Sample records for air mass exchange
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Extratropical Stratosphere-Troposphere Mass Exchange
NASA Technical Reports Server (NTRS)
Schoeberl, Mark R.
2004-01-01
Understanding the exchange of gases between the stratosphere and the troposphere is important for determining how pollutants enter the stratosphere and how they leave. This study does a global analysis of that the exchange of mass between the stratosphere and the troposphere. While the exchange of mass is not the same as the exchange of constituents, you can t get the constituent exchange right if you have the mass exchange wrong. Thus this kind of calculation is an important test for models which also compute trace gas transport. In this study I computed the mass exchange for two assimilated data sets and a GCM. The models all agree that amount of mass descending from the stratosphere to the troposphere in the Northern Hemisphere extra tropics is approx. 10(exp 10) kg/s averaged over a year. The value for the Southern Hemisphere by about a factor of two. ( 10(exp 10) kg of air is the amount of air in 100 km x 100 km area with a depth of 100 m - roughly the size of the D.C. metro area to a depth of 300 feet.) Most people have the idea that most of the mass enters the stratosphere through the tropics. But this study shows that almost 5 times more mass enters the stratosphere through the extra-tropics. This mass, however, is quickly recycled out again. Thus the lower most stratosphere is a mixture of upper stratospheric air and tropospheric air. This is an important result for understanding the chemistry of the lower stratosphere.
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Modelling heat and mass transfer in a membrane-based air-to-air enthalpy exchanger
NASA Astrophysics Data System (ADS)
Dugaria, S.; Moro, L.; Del, D., Col
2015-11-01
The diffusion of total energy recovery systems could lead to a significant reduction in the energy demand for building air-conditioning. With these devices, sensible heat and humidity can be recovered in winter from the exhaust airstream, while, in summer, the incoming air stream can be cooled and dehumidified by transferring the excess heat and moisture to the exhaust air stream. Membrane based enthalpy exchangers are composed by different channels separated by semi-permeable membranes. The membrane allows moisture transfer under vapour pressure difference, or water concentration difference, between the two sides and, at the same time, it is ideally impermeable to air and other contaminants present in exhaust air. Heat transfer between the airstreams occurs through the membrane due to the temperature gradient. The aim of this work is to develop a detailed model of the coupled heat and mass transfer mechanisms through the membrane between the two airstreams. After a review of the most relevant models published in the scientific literature, the governing equations are presented and some simplifying assumptions are analysed and discussed. As a result, a steady-state, two-dimensional finite difference numerical model is setup. The developed model is able to predict temperature and humidity evolution inside the channels. Sensible and latent heat transfer rate, as well as moisture transfer rate, are determined. A sensitive analysis is conducted in order to determine the more influential parameters on the thermal and vapour transfer.
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Boundary layers at a dynamic interface: air-sea exchange of heat and mass
NASA Astrophysics Data System (ADS)
Szeri, Andrew
2017-11-01
Exchange of mass or heat across a turbulent liquid-gas interface is a problem of critical interest, especially in air-sea transfer of natural and man-made gases involved in climate change. The goal in this research area is to determine the gas flux from air to sea or vice versa. For sparingly soluble non-reactive gases, this is controlled by liquid phase turbulent velocity fluctuations that act on the thin species concentration boundary layer on the liquid side of the interface. If the fluctuations in surface-normal velocity and gas concentration differences are known, then it is possible to determine the turbulent contribution to the gas flux. However, there is no suitable fundamental direct approach in the general case where neither of these quantities can be easily measured. A new approach is presented to deduce key aspects about the near-surface turbulent motions from remote measurements, which allows one to determine the gas transfer velocity, or gas flux per unit area if overall concentration differences are known. The approach is illustrated with conceptual examples.
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Heat Recovery Ventilation for Housing: Air-to-Air Heat Exchangers.
ERIC Educational Resources Information Center
Corbett, Robert J.; Miller, Barbara
The air-to-air heat exchanger (a fan powered ventilation device that recovers heat from stale outgoing air) is explained in this six-part publication. Topic areas addressed are: (1) the nature of air-to-air heat exchangers and how they work; (2) choosing and sizing the system; (3) installation, control, and maintenance of the system; (4) heat…
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Review of Air Exchange Rate Models for Air Pollution Exposure Assessments
A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings, where people spend their time. The AER, which is rate the exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pol...
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Water vapor mass balance method for determining air infiltration rates in houses
David R. DeWalle; Gordon M. Heisler
1980-01-01
A water vapor mass balance technique that includes the use of common humidity-control equipment can be used to determine average air infiltration rates in buildings. Only measurements of the humidity inside and outside the home, the mass of vapor exchanged by a humidifier/dehumidifier, and the volume of interior air space are needed. This method gives results that...
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Air-sea heat exchange, an element of the water cycle
NASA Technical Reports Server (NTRS)
Chahine, M. T.
1984-01-01
The distribution and variation of water vapor, clouds and precipitation are examined. Principal driving forces for these distributions are energy exchange and evaporation at the air-sea interface, which are also important elements of air-sea interaction studies. The overall aim of air-sea interaction studies is to quantitatively determine mass, momentum and energy fluxes, with the goal of understanding the mechanisms controlling them. The results of general circulation simulations indicate that the atmosphere in mid-latitudes responds to changes in the oceanic surface conditions in the tropics. This correlation reflects the strong interaction between tropical and mid-latitude conditions caused by the transport of heat and momentum from the tropics. Studies of air-sea exchanges involve a large number of physica, chemical and dynamical processes including heat flux, radiation, sea-surface temperature, precipitation, winds and ocean currents. The fluxes of latent heat are studied and the potential use of satellite data in determining them evaluated. Alternative ways of inferring heat fluxes will be considered.
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Air-water Gas Exchange Rates on a Large Impounded River Measured Using Floating Domes (Poster)
Mass balance models of dissolved gases in rivers typically serve as the basis for whole-system estimates of greenhouse gas emission rates. An important component of these models is the exchange of dissolved gases between air and water. Controls on gas exchange rates (K) have be...
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FACTORS AFFECTING AIR EXCHANGE IN TWO HOUSES
Air exchange rate is critical to determining the relationship between indoor and outdoor concentrations of hazardous pollutants. Approximately 150 air exchange experiments were completed in two residences: a two-story detached house located in Redwood City, CA and a three-story...
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Boundary layers at a dynamic interface: Air-sea exchange of heat and mass
NASA Astrophysics Data System (ADS)
Szeri, Andrew J.
2017-04-01
Exchange of mass or heat across a turbulent liquid-gas interface is a problem of critical interest, especially in air-sea transfer of natural and anthropogenic gases involved in the study of climate. The goal in this research area is to determine the gas flux from air to sea or vice versa. For sparingly soluble nonreactive gases, this is controlled by liquid phase turbulent velocity fluctuations that act on the thin species concentration boundary layer on the liquid side of the interface. If the fluctuations in surface-normal velocity w' and gas concentration c' are known, then it is possible to determine the turbulent contribution to the gas flux. However, there is no suitable fundamental direct approach in the general case where neither w' nor c' can be easily measured. A new approach is presented to deduce key aspects about the near-surface turbulent motions from measurements that can be taken by an infrared (IR) camera. An equation is derived with inputs being the surface temperature and heat flux, and a solution method developed for the surface-normal strain experienced over time by boundary layers at the interface. Because the thermal and concentration boundary layers experience the same near-surface fluid motions, the solution for the surface-normal strain determines the gas flux or gas transfer velocity. Examples illustrate the approach in the cases of complete surface renewal, partial surface renewal, and insolation. The prospects for use of the approach in flows characterized by sheared interfaces or rapid boundary layer straining are explored.
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Hydrogen/deuterium exchange in mass spectrometry.
Kostyukevich, Yury; Acter, Thamina; Zherebker, Alexander; Ahmed, Arif; Kim, Sunghwan; Nikolaev, Eugene
2018-03-30
The isotopic exchange approach is in use since the first observation of such reactions in 1933 by Lewis. This approach allows the investigation of the pathways of chemical and biochemical reactions, determination of structure, composition, and conformation of molecules. Mass spectrometry has now become one of the most important analytical tools for the monitoring of the isotopic exchange reactions. Investigation of conformational dynamics of proteins, quantitative measurements, obtaining chemical, and structural information about individual compounds of the complex natural mixtures are mainly based on the use of isotope exchange in combination with high resolution mass spectrometry. The most important reaction is the Hydrogen/Deuterium exchange, which is mainly performed in the solution. Recently we have developed the approach allowing performing of the Hydrogen/Deuterium reaction on-line directly in the ionization source under atmospheric pressure. Such approach simplifies the sample preparation and can accelerate the exchange reaction so that certain hydrogens that are considered as non-labile will also participate in the exchange. The use of in-ionization source H/D exchange in modern mass spectrometry for structural elucidation of molecules serves as the basic theme in this review. We will focus on the mechanisms of the isotopic exchange reactions and on the application of in-ESI, in-APCI, and in-APPI source Hydrogen/Deuterium exchange for the investigation of petroleum, natural organic matter, oligosaccharides, and proteins including protein-protein complexes. The simple scenario for adaptation of H/D exchange reactions into mass spectrometric method is also highlighted along with a couple of examples collected from previous studies. © 2018 Wiley Periodicals, Inc.
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Forecasting Foreign Currency Exchange Rates for Air Force Budgeting
2015-03-26
FORECASTING FOREIGN CURRENCY EXCHANGE RATES FOR AIR FORCE BUDGETING THESIS MARCH 2015...States. AFIT-ENV-MS-15-M-178 FORECASTING FOREIGN CURRENCY EXCHANGE RATES FOR AIR FORCE BUDGETING THESIS Presented to the Faculty...FORECASTING FOREIGN CURRENCY EXCHANGE RATES FOR AIR FORCE BUDGETING Nicholas R. Gardner, BS Captain, USAF Committee Membership: Lt Col Jonathan
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Air sparging: Air-water mass transfer coefficients
NASA Astrophysics Data System (ADS)
Braida, Washington J.; Ong, Say Kee
1998-12-01
Experiments investigating the mass transfer of several dissolved volatile organic compounds (VOCs) across the air-water interface were conducted using a single-air- channel air-sparging system. Three different porous media were used in the study. Air velocities ranged from 0.2 cm s-1 to 2.5 cm s-1. The tortuosity factor for each porous medium and the air-water mass transfer coefficients were estimated by fitting experimental data to a one-dimensional diffusion model. The estimated mass transfer coefficients KG ranged from 1.79 × 10-3 cm min-1 to 3.85 × 10-2 cm min-1. The estimated lumped gas phase mass transfer coefficients KGa were found to be directly related to the air diffusivity of the VOC, air velocity, and particle size, and inversely related to the Henry's law constant of the VOCs. Of the four parameters investigated, the parameter that controlled or had a dominant effect on the lumped gas phase mass transfer coefficient was the air diffusivity of the VOC. Two empirical models were developed by correlating the Damkohler and the modified air phase Sherwood numbers with the air phase Peclet number, Henry's law constant, and the reduced mean particle size of porous media. The correlation developed in this study may be used to obtain better predictions of mass transfer fluxes for field conditions.
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Effects of humidified and dry air on corneal endothelial cells during vitreal fluid-air exchange.
Cekiç, Osman; Ohji, Masahito; Hayashi, Atsushi; Fang, Xiao Y; Kusaka, Shunji; Tano, Yasuo
2002-07-01
To report the immediate anatomic and functional alterations in corneal endothelial cells following use of humidified air and dry air during vitreal fluid-air exchange in rabbits. Experimental study. Rabbits undergoing pars plana vitrectomy and lensectomy were perfused with either dry or humidified air during fluid-air exchange for designated durations. Three different experiments were performed. First, control and experimental corneas were examined by scanning electron microscopy (SEM). Second, corneas were stained with Phalloidin-FITC and examined by fluorescein microscopy. Finally, third, transendothelial permeability for carboxyfluorescein was determined using a diffusion chamber. While different from the corneal endothelial cells, those cells exposed to humidified air were less stressed than cells exposed to dry air by SEM. Actin cytoskeleton was found highly disorganized with dry air exposure. Humidified air maintained the normal actin cytoskeleton throughout the 20 minutes of fluid-air exchange. Paracellular carboxyfluorescein leakage was significantly higher in dry air insufflated eyes compared with that of the humidified air after 5, 10, and 20 minutes of fluid-air exchange (P =.002, P =.004, and P =.002, respectively). Dry air stress during fluid-air exchange causes significant immediate alterations in monolayer appearance, actin cytoskeleton, and barrier function of corneal endothelium in aphakic rabbit eyes. Use of humidified air largely prevents the alterations in monolayer appearance, actin cytoskeleton, and barrier function of corneal endothelial cells.
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Lin, Tian; Guo, Zhigang; Li, Yuanyuan; Nizzetto, Luca; Ma, Chuanliang; Chen, Yingjun
2015-05-05
Gaseous exchange fluxes of organochlorine pesticides (OCPs) across the air-water interface of the coastal East China Sea were determined in order to assess whether the contaminated plume of the Yangtze River could be an important regional source of OCPs to the atmosphere. Hexachlorocyclohexanes (HCHs), chlordane compounds (CHLs), and dichlorodiphenyltrichloroethanes (DDTs) were the most frequently detected OCPs in air and water. Air-water exchange was mainly characterized by net volatilization for all measured OCPs. The net gaseous exchange flux ranged 10-240 ng/(m2·day) for γ-HCH, 60-370 ng/(m2·day) for trans-CHL, 97-410 ng/(m2·day) for cis-CHL, and ∼0 (e.g., equilibrium) to 490 ng/(m2·day) for p,p'-DDE. We found that the plume of the large contaminated river can serve as a significant regional secondary atmospheric source of legacy contaminants released in the catchment. In particular, the sediment plume represented the relevant source of DDT compounds (especially p,p'-DDE) sustaining net degassing when clean air masses from the open ocean reached the plume area. In contrast, a mass balance showed that, for HCHs, contaminated river discharge (water and sediment) plumes were capable of sustaining volatilization throughout the year. These results demonstrate the inconsistencies in the fate of HCHs and DDTs in this large estuarine system with declining primary sources.
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Xie, Zhiyong; Lakaschus, Soenke; Ebinghaus, Ralf; Caba, Armando; Ruck, Wolfgang
2006-07-01
Concentrations of nonylphenol isomers (NP), tertiary octylphenol (t-OP) and nonylphenol monoethoxylate isomers (NP1EO) have been simultaneously determined in the sea water and atmosphere of the North Sea. A decreasing concentration profile appeared following the distance increasing from the coast to the central part of the North Sea. Air-sea exchanges of t-OP and NP were estimated using the two-film resistance model based upon relative air-water concentrations and experimentally derived Henry's law constant. The average of air-sea exchange fluxes was -12+/-6 ng m(-2)day(-1) for t-OP and -39+/-19 ng m(-2)day(-1) for NP, which indicates a net deposition is occurring. These results suggest that the air-sea vapour exchange is an important process that intervenes in the mass balance of alkylphenols in the North Sea.
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Lowenstein, Andrew; Sibilia, Marc J.; Miller, Jeffrey A.; Tonon, Thomas
2007-09-18
A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.
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Lowenstein, Andrew [Princeton, NJ; Sibilia, Marc J [Princeton, NJ; Miller, Jeffrey A [Hopewell, NJ; Tonon, Thomas [Princeton, NJ
2011-06-28
A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.
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78 FR 49484 - Exchange of Air Force Real Property for Non-Air Force Real Property
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-14
... DEPARTMENT OF DEFENSE Department of Air Force Exchange of Air Force Real Property for Non-Air Force Real Property SUMMARY: Notice identifies excess Federal real property under administrative jurisdiction of the United States Air Force it intends to exchange for real property not currently owned by the...
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Effect of humidity on posterior lens opacification during fluid-air exchange.
Harlan, J B; Lee, E T; Jensen, P S; de Juan, E
1999-06-01
To study the relationship of humidity and the rate of lens opacity formation during fluid-air exchange using an animal model. Vitrectomy and fluid-air exchange was carried out using 16 eyes of 8 pigmented rabbits. One eye of each rabbit was exposed to dry air and the fellow eye received humidified air using an intraocular air humidifier. In each case, the percent humidity of the intraocular air was measured using an in-line hygrometer. Elapsed time from initial air entry to lens feathering was recorded for each eye, with the surgeon-observer unaware of the percent humidity of the air infusion. In each rabbit, use of humidified air resulted in a delay in lens feathering (P<.02), with an overall increase in time to feathering of 80% for humidified air vs room air. Use of a humidifier during fluid-air exchange prolongs intraoperative lens clarity in the rabbit model, suggesting that humidified air should prolong lens clarity during phakic fluid-air exchange in patients. Use of humidified air during vitrectomy and fluid-air exchange may retard the intraoperative loss of lens clarity, promoting better visualization of the posterior segment and enhancing surgical performance.
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Analytical aspects of hydrogen exchange mass spectrometry
Engen, John R.; Wales, Thomas E.
2016-01-01
The analytical aspects of measuring hydrogen exchange by mass spectrometry are reviewed. The nature of analytical selectivity in hydrogen exchange is described followed by review of the analytical tools required to accomplish fragmentation, separation, and the mass spectrometry measurements under restrictive exchange quench conditions. In contrast to analytical quantitation that relies on measurements of peak intensity or area, quantitation in hydrogen exchange mass spectrometry depends on measuring a mass change with respect to an undeuterated or deuterated control, resulting in a value between zero and the maximum amount of deuterium that could be incorporated. Reliable quantitation is a function of experimental fidelity and to achieve high measurement reproducibility, a large number of experimental variables must be controlled during sample preparation and analysis. The method also reports on important qualitative aspects of the sample, including conformational heterogeneity and population dynamics. PMID:26048552
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Gas exchange rates across the sediment-water and air-water interfaces in south San Francisco Bay
Hartman, Blayne; Hammond, Douglas E.
1984-01-01
Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainty of the determinations, about 20%. The annual average of benthic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water interface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2–6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models.
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Performance evaluation on an air-cooled heat exchanger for alumina nanofluid under laminar flow.
Teng, Tun-Ping; Hung, Yi-Hsuan; Teng, Tun-Chien; Chen, Jyun-Hong
2011-08-09
This study analyzes the characteristics of alumina (Al2O3)/water nanofluid to determine the feasibility of its application in an air-cooled heat exchanger for heat dissipation for PEMFC or electronic chip cooling. The experimental sample was Al2O3/water nanofluid produced by the direct synthesis method at three different concentrations (0.5, 1.0, and 1.5 wt.%). The experiments in this study measured the thermal conductivity and viscosity of nanofluid with weight fractions and sample temperatures (20-60°C), and then used the nanofluid in an actual air-cooled heat exchanger to assess its heat exchange capacity and pressure drop under laminar flow. Experimental results show that the nanofluid has a higher heat exchange capacity than water, and a higher concentration of nanoparticles provides an even better ratio of the heat exchange. The maximum enhanced ratio of heat exchange and pressure drop for all the experimental parameters in this study was about 39% and 5.6%, respectively. In addition to nanoparticle concentration, the temperature and mass flow rates of the working fluid can affect the enhanced ratio of heat exchange and pressure drop of nanofluid. The cross-section aspect ratio of tube in the heat exchanger is another important factor to be taken into consideration.
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Performance evaluation on an air-cooled heat exchanger for alumina nanofluid under laminar flow
2011-01-01
This study analyzes the characteristics of alumina (Al2O3)/water nanofluid to determine the feasibility of its application in an air-cooled heat exchanger for heat dissipation for PEMFC or electronic chip cooling. The experimental sample was Al2O3/water nanofluid produced by the direct synthesis method at three different concentrations (0.5, 1.0, and 1.5 wt.%). The experiments in this study measured the thermal conductivity and viscosity of nanofluid with weight fractions and sample temperatures (20-60°C), and then used the nanofluid in an actual air-cooled heat exchanger to assess its heat exchange capacity and pressure drop under laminar flow. Experimental results show that the nanofluid has a higher heat exchange capacity than water, and a higher concentration of nanoparticles provides an even better ratio of the heat exchange. The maximum enhanced ratio of heat exchange and pressure drop for all the experimental parameters in this study was about 39% and 5.6%, respectively. In addition to nanoparticle concentration, the temperature and mass flow rates of the working fluid can affect the enhanced ratio of heat exchange and pressure drop of nanofluid. The cross-section aspect ratio of tube in the heat exchanger is another important factor to be taken into consideration. PMID:21827644
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NASA Astrophysics Data System (ADS)
Gromov, Sergey S.; Trifonova-Yakovleva, Alisa; Gromov, Sergey A.
2017-04-01
In this study, we attempt to quantify the uncertainties in air mass exchange in the lower troposphere across two regions of the Russian border in Eastern Siberia and the Russian Far East in 2000-2015. We use meteorological data from long-term air sound data (ASD) on mean layer winds [1] and from the ERA INTERIM re-analysis (EIR) project [2]. Using a transboundary exchange model, we estimate the total and net amounts of air crossing the boundary segments around Irkutsk (IR) and Vladivostok (VL) aerological stations. We compare transport terms derived (i) from the long-term wind statistics based on both ASD and EIR data, and (ii) from integrating 6h meteorological winds from EIR directly over the border segments cells. We find similar wind direction statistics in both meteorological datasets, however EIR favours stronger westerly winds at VL in summer, which results in more often air export from China to Russia in the Far East. There is less agreement on the wind strengths than wind directions between the datasets, with EIR often providing slower wind speeds. The resulting climatic (ASD) and directly (from EIR 6h terms) calculated non-equilibrium (net) transport terms are comparable in orders (tens of million km3/month), however may differ substantially in temporal evolution or/and magnitude. Thus, EIR net transport over the IR segment has similar annual dynamics but is higher by a factor of ˜ 4 (maxima of 3.6 vs. 12 of 106 km3/month in December, respectively). An opposite ratio is derived for the VL segment (average ˜ 6 vs. 13 of 106 km3/month), with a distinct seasonality in the ASD but not in the EIR data. We attribute this discrepancy to the variations in wind direction with altitude, which cannot be resolved in the model fed with the ASD data. Calculated transport in the boundary layer (BL, provided by the EIR) supports this inference. Thus, the BL net transport temporal dynamics differ substantially from that within the 3 km layer, owing to the BL diurnal
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Surfactant control of air-sea gas exchange across contrasting biogeochemical regimes
NASA Astrophysics Data System (ADS)
Pereira, Ryan; Schneider-Zapp, Klaus; Upstill-Goddard, Robert
2014-05-01
months likely from primary production and spatially there is less suppression of air-sea gas exchange with increasing distance from the shoreline, which is likely due to riverine inputs. REFERENCES Bock, E. J., Hara, T., Frew, N. M., and McGillis, W. R., 1999. Relationship between air-sea gas transfer and short wind waves. Journal of Geophysical Research-Oceans 104, 25821-25831. Brockmann, U. H., Huhnerfuss, H., Kattner, G., Broecker, H. C., and Hentzschel, G., 1982. Artificial surface-films in the sea area near sylt. Limnology and Oceanography 27, 1050-1058. Goldman, J. C., Dennett, M. R., and Frew, N. M., 1988. Surfactant effects on air sea gas-exchange under turbulent conditions. Deep-Sea Research Part a-Oceanographic Research Papers 35, 1953-1970. McKenna, S. P. and McGillis, W. R., 2004. The role of free-surface turbulence and surfactants in air-water gas transfer. International Journal of Heat and Mass Transfer 47, 539-553. Salter, M. E., R. C. Upstill-Goddard, P. D. Nightingale, S. D. Archer, B. Blomquist, D. T. Ho, B. Huebert, P. Schlosser, and M. Yang (2011), Impact of an artificial surfactant release on air-sea gas fluxes during Deep Ocean Gas Exchange Experiment II, J. Geophys. Res., 116, C11016, doi:10.1029/2011JC00702 Takahashi, T., Sutherland, S. C., Wanninkhof, R., Sweeney, C., Feely, R. A., Chipman, D. W., Hales, B., Friederich, G., Chavez, F., Sabine, C., Watson, A., Bakker, D. C. E., Schuster, U., Metzl, N., Yoshikawa-Inoue, H., Ishii, M., Midorikawa, T., Nojiri, Y., Körtzinger, A., Steinhoff, T., Hoppema, M., Olafsson, J., Arnarson, T. S., Tilbrook, B., Johannessen, T., Olsen, A., Bellerby, R., Wong, C. S., Delille, B., Bates, N. R., and de Baar, H. J. W., 2009. Climatological mean and decadal change in surface ocean pCO 2, and net sea-air CO 2 flux over the global oceans. Deep-Sea Research Part II: Topical Studies in Oceanography 56, 554-577.
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On factors influencing air-water gas exchange in emergent wetlands
Ho, David T.; Engel, Victor C.; Ferron, Sara; Hickman, Benjamin; Choi, Jay; Harvey, Judson W.
2018-01-01
Knowledge of gas exchange in wetlands is important in order to determine fluxes of climatically and biogeochemically important trace gases and to conduct mass balances for metabolism studies. Very few studies have been conducted to quantify gas transfer velocities in wetlands, and many wind speed/gas exchange parameterizations used in oceanographic or limnological settings are inappropriate under conditions found in wetlands. Here six measurements of gas transfer velocities are made with SF6 tracer release experiments in three different years in the Everglades, a subtropical peatland with surface water flowing through emergent vegetation. The experiments were conducted under different flow conditions and with different amounts of emergent vegetation to determine the influence of wind, rain, water flow, waterside thermal convection, and vegetation on air-water gas exchange in wetlands. Measured gas transfer velocities under the different conditions ranged from 1.1 cm h−1 during baseline conditions to 3.2 cm h−1 when rain and water flow rates were high. Commonly used wind speed/gas exchange relationships would overestimate the gas transfer velocity by a factor of 1.2 to 6.8. Gas exchange due to thermal convection was relatively constant and accounted for 14 to 51% of the total measured gas exchange. Differences in rain and water flow among the different years were responsible for the variability in gas exchange, with flow accounting for 37 to 77% of the gas exchange, and rain responsible for up to 40%.
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A review of air exchange rate models for air pollution exposure assessments.
Breen, Michael S; Schultz, Bradley D; Sohn, Michael D; Long, Thomas; Langstaff, John; Williams, Ronald; Isaacs, Kristin; Meng, Qing Yu; Stallings, Casson; Smith, Luther
2014-11-01
A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings where people spend their time. The AER, which is the rate of exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pollutants and for removal of indoor-emitted air pollutants. This paper presents an overview and critical analysis of the scientific literature on empirical and physically based AER models for residential and commercial buildings; the models highlighted here are feasible for exposure assessments as extensive inputs are not required. Models are included for the three types of airflows that can occur across building envelopes: leakage, natural ventilation, and mechanical ventilation. Guidance is provided to select the preferable AER model based on available data, desired temporal resolution, types of airflows, and types of buildings included in the exposure assessment. For exposure assessments with some limited building leakage or AER measurements, strategies are described to reduce AER model uncertainty. This review will facilitate the selection of AER models in support of air pollution exposure assessments.
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NASA Astrophysics Data System (ADS)
Wu, Z.; Guo, Z.
2017-12-01
We measured 15 parent polycyclic aromatic hydrocarbons (PAHs) in atmosphere and water during a research cruise from the East China Sea (ECS) to the northwestern Pacific Ocean (NWP) in the spring of 2015 to investigate the occurrence, air-sea gas exchange, and gas-particle partitioning of PAHs with a particular focus on the influence of East Asian continental outflow. The gaseous PAH composition and identification of sources were consistent with PAHs from the upwind area, indicating that the gaseous PAHs (three- to five-ring PAHs) were influenced by upwind land pollution. In addition, air-sea exchange fluxes of gaseous PAHs were estimated to be -54.2 to 107.4 ng m-2 d-1, and was indicative of variations of land-based PAH inputs. The logarithmic gas-particle partition coefficient (logKp) of PAHs regressed linearly against the logarithmic subcooled liquid vapor pressure, with a slope of -0.25. This was significantly larger than the theoretical value (-1), implying disequilibrium between the gaseous and particulate PAHs over the NWP. The non-equilibrium of PAH gas-particle partitioning was shielded from the volatilization of three-ring gaseous PAHs from seawater and lower soot concentrations in particular when the oceanic air masses prevailed. Modeling PAH absorption into organic matter and adsorption onto soot carbon revealed that the status of PAH gas-particle partitioning deviated more from the modeling Kp for oceanic air masses than those for continental air masses, which coincided with higher volatilization of three-ring PAHs and confirmed the influence of air-sea exchange. Meanwhile, significant linear regressions between logKp and logKoa (logKsa) for PAHs were observed for continental air masses, suggesting the dominant effect of East Asian continental outflow on atmospheric PAHs over the NWP during the sampling campaign.
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Microchannel laminated mass exchanger and method of making
Martin, Peter M [Kennewick, WA; Bennett, Wendy D [Kennewick, WA; Matson, Dean W [Kennewick, WA; Stewart, Donald C [Richland, WA; Drost, Monte K [Pasco, WA; Wegeng, Robert S [Richland, WA; Perez, Joseph M [Richland, WA; Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA
2003-03-18
The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.
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Microchannel laminated mass exchanger and method of making
Martin, Peter M.; Bennett, Wendy D.; Matson, Dean W.; Stewart, Donald C.; Drost, Monte K.; Wegeng, Robert S.; Perez, Joseph M.; Feng, Xiangdong; Liu, Jun
2000-01-01
The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.
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Microchannel laminated mass exchanger and method of making
Martin, Peter M [Kennewick, WA; Bennett, Wendy D [Kennewick, WA; Matson, Dean W [Kennewick, WA; Stewart, Donald C [Richland, WA; Drost, Monte K [Pasco, WA; Wegeng, Robert S [Richland, WA; Perez, Joseph M [Richland, WA; Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA
2002-03-05
The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.
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Continuous measurement of air-water gas exchange by underwater eddy covariance
NASA Astrophysics Data System (ADS)
Berg, Peter; Pace, Michael L.
2017-12-01
Exchange of gases, such as O2, CO2, and CH4, over the air-water interface is an important component in aquatic ecosystem studies, but exchange rates are typically measured or estimated with substantial uncertainties. This diminishes the precision of common ecosystem assessments associated with gas exchanges such as primary production, respiration, and greenhouse gas emission. Here, we used the aquatic eddy covariance technique - originally developed for benthic O2 flux measurements - right below the air-water interface (˜ 4 cm) to determine gas exchange rates and coefficients. Using an acoustic Doppler velocimeter and a fast-responding dual O2-temperature sensor mounted on a floating platform the 3-D water velocity, O2 concentration, and temperature were measured at high-speed (64 Hz). By combining these data, concurrent vertical fluxes of O2 and heat across the air-water interface were derived, and gas exchange coefficients were calculated from the former. Proof-of-concept deployments at different river sites gave standard gas exchange coefficients (k600) in the range of published values. A 40 h long deployment revealed a distinct diurnal pattern in air-water exchange of O2 that was controlled largely by physical processes (e.g., diurnal variations in air temperature and associated air-water heat fluxes) and not by biological activity (primary production and respiration). This physical control of gas exchange can be prevalent in lotic systems and adds uncertainty to assessments of biological activity that are based on measured water column O2 concentration changes. For example, in the 40 h deployment, there was near-constant river flow and insignificant winds - two main drivers of lotic gas exchange - but we found gas exchange coefficients that varied by several fold. This was presumably caused by the formation and erosion of vertical temperature-density gradients in the surface water driven by the heat flux into or out of the river that affected the turbulent
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Gustafson, K.E.; Dickhut, R.M.
1995-12-31
The gaseous exchange fluxes of polycyclic aromatic hydrocarbons (PAHs) across the air-water interface of lower Chesapeake Bay were determined using a modified two-film exchange model. Sampling covered the period January 1994 to June 1995 for five sites on lower Chesapeake Bay ranging from rural to urban and highly industrialized. Simultaneous air and water samples were collected and the atmospheric gas phase and water column dissolved phase analyzed via GC/MS for 17 PAHs. The direction and magnitude of flux for each PAH was calculated using Henry`s law constants, hydrological and meteorological parameters, Temperature was observed to be an important environmental factormore » in determining both the direction and magnitude of PAH gas exchange. Nonetheless, wind speed significantly impacts mass transfer coefficients, and therefore was found to control the magnitude of flux. Spatial and temporal variation of PAH gaseous exchange fluxes were examined. Fluxes were determined to be both into and out of Chesapeake Bay. The range of gas exchange fluxes ({minus}560 to 600{micro}g/M{sup 2}*Mo) is of the same order to 10X greater than atmospheric wet and dry depositional fluxes to lower Chesapeake Bay. The results of this study support the hypothesis that gas exchange is a major transport process affecting the net loadings of PAHs in lower Chesapeake Bay.« less
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Quanico, Jusal; Franck, Julien
2016-01-01
Hydrogen/deuterium exchange mass spectrometric (H/DXMS) methods for protein structural analysis are conventionally performed in solution. We present Tissue Deuterium Exchange Mass Spectrometry (TDXMS), a method to directly monitor deuterium uptake on tissue, as a means to better approximate the deuterium exchange behavior of proteins in their native microenvironment. Using this method, a difference in deuterium uptake behavior was observed when the same proteins were monitored in solution and on tissue. The higher maximum deuterium uptake at equilibrium for all proteins analyzed in solution suggests a more open conformation in the absence of interacting partners normally observed on tissue. We also demonstrate a difference in the deuterium uptake behavior of a few proteins across different morphological regions of the same tissue section. Modifications of the total number of hydrogens exchanged, as well as the kinetics of exchange, were both observed. These results provide information on the implication of protein interactions with partners as well as on the conformational changes related to these interactions, and illustrate the importance of examining protein deuterium exchange behavior in the presence of its specific microenvironment directly at the level of tissues. PMID:27512083
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Spume Drops: Their Potential Role in Air-Sea Gas Exchange
NASA Astrophysics Data System (ADS)
Monahan, Edward C.; Staniec, Allison; Vlahos, Penny
2017-12-01
After summarizing the time scales defining the change of the physical properties of spume and other droplets cast up from the sea surface, the time scales governing drop-atmosphere gas exchange are compared. Following a broad review of the spume drop production functions described in the literature, a subset of these functions is selected via objective criteria, to represent typical, upper bound, and lower bound production functions. Three complementary mechanisms driving spume-atmosphere gas exchange are described, and one is then used to estimate the relative importance, over a broad range of wind speeds, of this spume drop mechanism compared to the conventional, diffusional, sea surface mechanism in air-sea gas exchange. While remaining uncertainties in the wind dependence of the spume drop production flux, and in the immediate sea surface gas flux, preclude a definitive conclusion, the findings of this study strongly suggest that, at high wind speeds (>20 m s-1 for dimethyl sulfide and >30 m s-1 for gases such a carbon dioxide), spume drops do make a significant contribution to air-sea gas exchange.
Plain Language SummaryThis paper evaluates the existing spume drop generation functions available to date and selects a reasonable upper, lower and mid range function that are reasonable for use in <span class="hlt">air</span> sea <span class="hlt">exchange</span> models. Based on these the contribution of spume drops to overall <span class="hlt">air</span> sea gas <span class="hlt">exchange</span> at different wind speeds is then evaluated to determine the % contribution of spume. Generally below 20ms-1 spume drops contribute <1% of gas <span class="hlt">exchange</span> but may account for a significant amount of gas <span class="hlt">exchange</span> at higher wind speeds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3497365','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3497365"><span>Seasonal Variations of Indoor Microbial Exposures and Their Relation to Temperature, Relative Humidity, and <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rate</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bekö, Gabriel; Timm, Michael; Gustavsen, Sine; Hansen, Erik Wind</p> <p>2012-01-01</p> <p>Indoor microbial exposure has been related to adverse pulmonary health effects. Exposure assessment is not standardized, and various factors may affect the measured exposure. The aim of this study was to investigate the seasonal variation of selected microbial exposures and their associations with temperature, relative humidity, and <span class="hlt">air</span> <span class="hlt">exchange</span> rates in Danish homes. Airborne inhalable dust was sampled in five Danish homes throughout the four seasons of 1 year (indoors, n = 127; outdoors, n = 37). Measurements included culturable fungi and bacteria, endotoxin, N-acetyl-beta-d-glucosaminidase, total inflammatory potential, particles (0.75 to 15 μm), temperature, relative humidity, and <span class="hlt">air</span> <span class="hlt">exchange</span> rates. Significant seasonal variation was found for all indoor microbial exposures, excluding endotoxin. Indoor fungi peaked in summer (median, 235 CFU/m3) and were lowest in winter (median, 26 CFU/m3). Indoor bacteria peaked in spring (median, 2,165 CFU/m3) and were lowest in summer (median, 240 CFU/m3). Concentrations of fungi were predominately higher outdoors than indoors, whereas bacteria, endotoxin, and inhalable dust concentrations were highest indoors. Bacteria and endotoxin correlated with the <span class="hlt">mass</span> of inhalable dust and number of particles. Temperature and <span class="hlt">air</span> <span class="hlt">exchange</span> rates were positively associated with fungi and N-acetyl-beta-d-glucosaminidase and negatively with bacteria and the total inflammatory potential. Although temperature, relative humidity, and <span class="hlt">air</span> <span class="hlt">exchange</span> rates were significantly associated with several indoor microbial exposures, they could not fully explain the observed seasonal variations when tested in a mixed statistical model. In conclusion, the season significantly affects indoor microbial exposures, which are influenced by temperature, relative humidity, and <span class="hlt">air</span> <span class="hlt">exchange</span> rates. PMID:23001651</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/7300088-operating-experiences-rotary-air-air-heat-exchangers-hospitals-schools-nursing-homes-swimming-pools','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/7300088-operating-experiences-rotary-air-air-heat-exchangers-hospitals-schools-nursing-homes-swimming-pools"><span>Operating experiences with rotary <span class="hlt">air-to-air</span> heat <span class="hlt">exchangers</span>: hospitals, schools, nursing homes, swimming pools</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Pearson, R.J.</p> <p>1976-01-01</p> <p>Systems utilizing rotary <span class="hlt">air-to-air</span> heat <span class="hlt">exchangers</span> are discussed. Basic considerations of use (fresh <span class="hlt">air</span> requirements, system configurations, cost considerations), typical system layout/design considerations, and operating observations by engineers, staff and maintenance personnel are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28675854','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28675854"><span><span class="hlt">Air</span>-sea <span class="hlt">exchange</span> and gas-particle partitioning of polycyclic aromatic hydrocarbons over the northwestern Pacific Ocean: Role of East Asian continental outflow.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Zilan; Lin, Tian; Li, Zhongxia; Jiang, Yuqing; Li, Yuanyuan; Yao, Xiaohong; Gao, Huiwang; Guo, Zhigang</p> <p>2017-11-01</p> <p>We measured 15 parent polycyclic aromatic hydrocarbons (PAHs) in atmosphere and water during a research cruise from the East China Sea (ECS) to the northwestern Pacific Ocean (NWP) in the spring of 2015 to investigate the occurrence, <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span>, and gas-particle partitioning of PAHs with a particular focus on the influence of East Asian continental outflow. The gaseous PAH composition and identification of sources were consistent with PAHs from the upwind area, indicating that the gaseous PAHs (three-to five-ring PAHs) were influenced by upwind land pollution. In addition, <span class="hlt">air</span>-sea <span class="hlt">exchange</span> fluxes of gaseous PAHs were estimated to be -54.2-107.4 ng m -2 d -1 , and was indicative of variations of land-based PAH inputs. The logarithmic gas-particle partition coefficient (logK p ) of PAHs regressed linearly against the logarithmic subcooled liquid vapor pressure (logP L 0 ), with a slope of -0.25. This was significantly larger than the theoretical value (-1), implying disequilibrium between the gaseous and particulate PAHs over the NWP. The non-equilibrium of PAH gas-particle partitioning was shielded from the volatilization of three-ring gaseous PAHs from seawater and lower soot concentrations in particular when the oceanic <span class="hlt">air</span> <span class="hlt">masses</span> prevailed. Modeling PAH absorption into organic matter and adsorption onto soot carbon revealed that the status of PAH gas-particle partitioning deviated more from the modeling K p for oceanic <span class="hlt">air</span> <span class="hlt">masses</span> than those for continental <span class="hlt">air</span> <span class="hlt">masses</span>, which coincided with higher volatilization of three-ring PAHs and confirmed the influence of <span class="hlt">air</span>-sea <span class="hlt">exchange</span>. Meanwhile, significant linear regressions between logK p and logK oa (logK sa ) for PAHs were observed for continental <span class="hlt">air</span> <span class="hlt">masses</span>, suggesting the dominant effect of East Asian continental outflow on atmospheric PAHs over the NWP during the sampling campaign. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS31B1280P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS31B1280P"><span>Micrometeorological Measurement of Fetch- and Atmospheric Stability-Dependent <span class="hlt">Air</span>- Water <span class="hlt">Exchange</span> of Legacy Semivolatile Organic Contaminants in Lake Superior</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perlinger, J. A.; Tobias, D. E.; Rowe, M. D.</p> <p>2008-12-01</p> <p>Coastal waters including the Laurentian Great Lakes are particularly susceptible to local, regional, and long- range transport and deposition of semivolatile organic contaminants (SOCs) as gases and/or associated with particles. Recently-marketed SOCs can be expected to undergo net deposition in surface waters, whereas legacy SOCs such as polychlorinated biphenyls (PCBs) are likely to be at equilibrium with respect to <span class="hlt">air</span>-water <span class="hlt">exchange</span>, or, if atmospheric concentrations decrease through, e.g., policy implementation, to undergo net gas emission. SOC <span class="hlt">air</span>-water <span class="hlt">exchange</span> flux is usually estimated using the two-film model. This model describes molecular diffusion through the <span class="hlt">air</span> and water films adjacent to the <span class="hlt">air</span>-water interface. <span class="hlt">Air</span>-water <span class="hlt">exchange</span> flux is estimated as the product of SOC fugacity, typically based on on-shore gaseous concentration measurements, and a transfer coefficient, the latter which is estimated from SOC properties and environmental conditions. The transfer coefficient formulation commonly applied neglects resistance to <span class="hlt">exchange</span> in the internal boundary layer under atmospherically stable conditions, and the use of on-shore gaseous concentration neglects fetch-dependent equilibration, both of which will tend to cause overestimation of flux magnitude. Thus, for legacy chemicals or in any highly contaminated surface water, the rate at which the water is cleansed through gas emission tends to be over-predicted using this approach. Micrometeorological measurement of <span class="hlt">air</span>-water <span class="hlt">exchange</span> rates of legacy SOCs was carried out on ships during four transect experiments during off-shore flow in Lake Superior using novel multicapillary collection devices and thermal extraction technology to measure parts-per-quadrillion SOC levels. Employing sensible heat in the modified Bowen ratio, fluxes at three over-water stations along the transects were measured, along with up-wind, onshore gaseous concentration and aqueous concentration. The atmosphere was unstable for</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.891a2135C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.891a2135C"><span>Research on Heat <span class="hlt">Exchange</span> Process in Aircraft <span class="hlt">Air</span> Conditioning System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chichindaev, A. V.</p> <p>2017-11-01</p> <p>Using of heat-<span class="hlt">exchanger</span>-condenser in the <span class="hlt">air</span> conditioning system of the airplane Tu-204 (Boeing, Airbus, Superjet 100, MS-21, etc.) for cooling the compressed <span class="hlt">air</span> by the cold <span class="hlt">air</span> with negative temperature exiting the turbine results in a number of operational problems. Mainly it’s frosting of the heat <span class="hlt">exchange</span> surface, which is the cause of live-section channels frosting, resistance increasing and airflow in the system decreasing. The purpose of this work is to analyse the known freeze-up-fighting methods for heat-<span class="hlt">exchanger</span>-condenser, description of the features of anti-icing protection and offering solutions to this problem. For the problem of optimizing the design of heat <span class="hlt">exchangers</span> in this work used generalized criterion that describes the ratio of thermal resistances of cold and hot sections, which include: the ratio of the initial values of heat transfer agents flow state; heat <span class="hlt">exchange</span> surface finning coefficients; factors which describes the ratio of operating parameters and finning area. By controlling the ratio of the thermal resistances can be obtained the desired temperature of the heat <span class="hlt">exchange</span> surface, which would prevent freezing. The work presents the results of a numerical study of the effect of different combinations of regime and geometrical factors changes on reduction of the heat-<span class="hlt">exchanger</span>-condenser freezing surface area, including using of variable ratio of thermal resistances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100026667','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100026667"><span>A <span class="hlt">Mass</span> Computation Model for Lightweight Brayton Cycle Regenerator Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Juhasz, Albert J.</p> <p>2010-01-01</p> <p>Based on a theoretical analysis of convective heat transfer across large internal surface areas, this paper discusses the design implications for generating lightweight gas-gas heat <span class="hlt">exchanger</span> designs by packaging such areas into compact three-dimensional shapes. Allowances are made for hot and cold inlet and outlet headers for assembly of completed regenerator (or recuperator) heat <span class="hlt">exchanger</span> units into closed cycle gas turbine flow ducting. Surface area and resulting volume and <span class="hlt">mass</span> requirements are computed for a range of heat <span class="hlt">exchanger</span> effectiveness values and internal heat transfer coefficients. Benefit cost curves show the effect of increasing heat <span class="hlt">exchanger</span> effectiveness on Brayton cycle thermodynamic efficiency on the plus side, while also illustrating the cost in heat <span class="hlt">exchanger</span> required surface area, volume, and <span class="hlt">mass</span> requirements as effectiveness is increased. The equations derived for counterflow and crossflow configurations show that as effectiveness values approach unity, or 100 percent, the required surface area, and hence heat <span class="hlt">exchanger</span> volume and <span class="hlt">mass</span> tend toward infinity, since the implication is that heat is transferred at a zero temperature difference. To verify the dimensional accuracy of the regenerator <span class="hlt">mass</span> computational procedure, calculation of a regenerator specific <span class="hlt">mass</span>, that is, heat <span class="hlt">exchanger</span> weight per unit working fluid <span class="hlt">mass</span> flow, is performed in both English and SI units. Identical numerical values for the specific <span class="hlt">mass</span> parameter, whether expressed in lb/(lb/sec) or kg/(kg/sec), show the dimensional consistency of overall results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100037206','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100037206"><span>A <span class="hlt">Mass</span> Computation Model for Lightweight Brayton Cycle Regenerator Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Juhasz, Albert J.</p> <p>2010-01-01</p> <p>Based on a theoretical analysis of convective heat transfer across large internal surface areas, this paper discusses the design implications for generating lightweight gas-gas heat <span class="hlt">exchanger</span> designs by packaging such areas into compact three-dimensional shapes. Allowances are made for hot and cold inlet and outlet headers for assembly of completed regenerator (or recuperator) heat <span class="hlt">exchanger</span> units into closed cycle gas turbine flow ducting. Surface area and resulting volume and <span class="hlt">mass</span> requirements are computed for a range of heat <span class="hlt">exchanger</span> effectiveness values and internal heat transfer coefficients. Benefit cost curves show the effect of increasing heat <span class="hlt">exchanger</span> effectiveness on Brayton cycle thermodynamic efficiency on the plus side, while also illustrating the cost in heat <span class="hlt">exchanger</span> required surface area, volume, and <span class="hlt">mass</span> requirements as effectiveness is increased. The equations derived for counterflow and crossflow configurations show that as effectiveness values approach unity, or 100 percent, the required surface area, and hence heat <span class="hlt">exchanger</span> volume and <span class="hlt">mass</span> tend toward infinity, since the implication is that heat is transferred at a zero temperature difference. To verify the dimensional accuracy of the regenerator <span class="hlt">mass</span> computational procedure, calculation of a regenerator specific <span class="hlt">mass</span>, that is, heat <span class="hlt">exchanger</span> weight per unit working fluid <span class="hlt">mass</span> flow, is performed in both English and SI units. Identical numerical values for the specific <span class="hlt">mass</span> parameter, whether expressed in lb/(lb/sec) or kg/ (kg/sec), show the dimensional consistency of overall results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27..874S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27..874S"><span>Observational Studies of Parameters Influencing <span class="hlt">Air</span>-sea Gas <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schimpf, U.; Frew, N. M.; Bock, E. J.; Hara, T.; Garbe, C. S.; Jaehne, B.</p> <p></p> <p>A physically-based modeling of the <span class="hlt">air</span>-sea gas transfer that can be used to predict the gas transfer rates with sufficient accuracy as a function of micrometeorological parameters is still lacking. State of the art are still simple gas transfer rate/wind speed relationships. Previous measurements from Coastal Ocean Experiment in the Atlantic revealed positive correlations between mean square slope, near surface turbulent dis- sipation, and wind stress. It also demonstrated a strong negative correlation between mean square slope and the fluorescence of surface-enriched colored dissolved organic matter. Using heat as a proxy tracer for gases the <span class="hlt">exchange</span> process at the <span class="hlt">air</span>/water interface and the micro turbulence at the water surface can be investigated. The anal- ysis of infrared image sequences allow the determination of the net heat flux at the ocean surface, the temperature gradient across the <span class="hlt">air</span>/sea interface and thus the heat transfer velocity and gas transfer velocity respectively. Laboratory studies were carried out in the new Heidelberg wind-wave facility AELOTRON. Direct measurements of the Schmidt number exponent were done in conjunction with classical <span class="hlt">mass</span> balance methods to estimate the transfer velocity. The laboratory results allowed to validate the basic assumptions of the so called controlled flux technique by applying differ- ent tracers for the gas <span class="hlt">exchange</span> in a large Schmidt number regime. Thus a modeling of the Schmidt number exponent is able to fill the gap between laboratory and field measurements field. Both, the results from the laboratory and the field measurements should be able to give a further understanding of the mechanisms controlling the trans- port processes across the aqueous boundary layer and to relate the forcing functions to parameters measured by remote sensing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5858910','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5858910"><span>Hydrogen <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mayne, Leland</p> <p>2018-01-01</p> <p>Hydrogen <span class="hlt">exchange</span> (HX) methods can reveal much about the structure, energetics, and dynamics of proteins. The addition of <span class="hlt">mass</span> spectrometry (MS) to an earlier fragmentation-separation HX analysis now extends HX studies to larger proteins at high structural resolution and can provide information not available before. This chapter discusses experimental aspects of HX labeling, especially with respect to the use of MS and the analysis of MS data. PMID:26791986</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IJMPS..2460002Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IJMPS..2460002Z"><span><span class="hlt">Air</span> Pressure Controlled <span class="hlt">Mass</span> Measurement System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhong, Ruilin; Wang, Jian; Cai, Changqing; Yao, Hong; Ding, Jin'an; Zhang, Yue; Wang, Xiaolei</p> <p></p> <p><span class="hlt">Mass</span> measurement is influenced by <span class="hlt">air</span> pressure, temperature, humidity and other facts. In order to reduce the influence, <span class="hlt">mass</span> laboratory of National Institute of Metrology, China has developed an <span class="hlt">air</span> pressure controlled <span class="hlt">mass</span> measurement system. In this system, an automatic <span class="hlt">mass</span> comparator is installed in an airtight chamber. The Chamber is equipped with a pressure controller and associate valves, thus the <span class="hlt">air</span> pressure can be changed and stabilized to the pre-set value, the preferred pressure range is from 200 hPa to 1100 hPa. In order to keep the environment inside the chamber stable, the display and control part of the <span class="hlt">mass</span> comparator are moved outside the chamber, and connected to the <span class="hlt">mass</span> comparator by feed-throughs. Also a lifting device is designed for this system which can easily lift up the upper part of the chamber, thus weights can be easily put inside the <span class="hlt">mass</span> comparator. The whole system is put on a marble platform, and the temperature and humidity of the laboratory is very stable. The temperature, humidity, and carbon dioxide content inside the chamber are measured in real time and can be used to get <span class="hlt">air</span> density. <span class="hlt">Mass</span> measurement cycle from 1100 hPa to 200 hPa and back to 1100 hPa shows the effective of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/864049','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/864049"><span>Fluidized bed heat <span class="hlt">exchanger</span> with water cooled <span class="hlt">air</span> distributor and dust hopper</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Jukkola, Walfred W.; Leon, Albert M.; Van Dyk, Jr., Garritt C.; McCoy, Daniel E.; Fisher, Barry L.; Saiers, Timothy L.; Karstetter, Marlin E.</p> <p>1981-11-24</p> <p>A fluidized bed heat <span class="hlt">exchanger</span> is provided in which <span class="hlt">air</span> is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat <span class="hlt">exchange</span> and the housing of the heat <span class="hlt">exchanger</span> has a water-wall type construction. Vertical in-bed heat <span class="hlt">exchange</span> tubes are provided and the <span class="hlt">air</span> distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat <span class="hlt">exchange</span> tubes are provided to extract heat from the exiting combustion gases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1212391','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1212391"><span>Metal-<span class="hlt">air</span> cell with ion <span class="hlt">exchange</span> material</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan</p> <p>2015-08-25</p> <p>Embodiments of the invention are related to anion <span class="hlt">exchange</span> membranes used in electrochemical metal-<span class="hlt">air</span> cells in which the membranes function as the electrolyte material, or are used in conjunction with electrolytes such as ionic liquid electrolytes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA282842','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA282842"><span>Oceanic Whitecaps and Associated, Bubble-Mediated, <span class="hlt">Air</span>-Sea <span class="hlt">Exchange</span> Processes</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1992-10-01</p> <p>experiments performed in laboratory conditions using <span class="hlt">Air</span>-Sea <span class="hlt">Exchange</span> Monitoring System (A-SEMS). EXPERIMENTAL SET-UP In a first look, the <span class="hlt">Air</span>-Sea <span class="hlt">Exchange</span>...Model 225, equipped with a Model 519 plug-in module. Other complementary information on A-SEMS along with results from first tests and calibration...between 9.50C and 22.40C within the first 24 hours after transferring the water sample into laboratory conditions. The results show an enhancement of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150020902','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150020902"><span>Technology Candidates for <span class="hlt">Air-to-Air</span> and <span class="hlt">Air</span>-to-Ground Data <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Haynes, Brian D.</p> <p>2015-01-01</p> <p>Technology Candidates for <span class="hlt">Air-to-Air</span> and <span class="hlt">Air</span>-to-Ground Data <span class="hlt">Exchange</span> is a two-year research effort to visualize the U. S. aviation industry at a point 50 years in the future, and to define potential communication solutions to meet those future data <span class="hlt">exchange</span> needs. The research team, led by XCELAR, was tasked with identifying future National Airspace System (NAS) scenarios, determining requirements and functions (including gaps), investigating technical and business issues for <span class="hlt">air</span>, ground, & <span class="hlt">air</span>-to-ground interactions, and reporting on the results. The project was conducted under technical direction from NASA and in collaboration with XCELAR's partner, National Institute of Aerospace, and NASA technical representatives. Parallel efforts were initiated to define the information <span class="hlt">exchange</span> functional needs of the future NAS, and specific communication link technologies to potentially serve those needs. Those efforts converged with the mapping of each identified future NAS function to potential enabling communication solutions; those solutions were then compared with, and ranked relative to, each other on a technical basis in a structured analysis process. The technical solutions emerging from that process were then assessed from a business case perspective to determine their viability from a real-world adoption and deployment standpoint. The results of that analysis produced a proposed set of future solutions and most promising candidate technologies. Gap analyses were conducted at two points in the process, the first examining technical factors, and the second as part of the business case analysis. In each case, no gaps or unmet needs were identified in applying the solutions evaluated to the requirements identified. The future communication solutions identified in the research comprise both specific link technologies and two enabling technologies that apply to most or all specific links. As a result, the research resulted in a new analysis approach, viewing the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EPJWC..6702023D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EPJWC..6702023D"><span>Heat <span class="hlt">exchanger</span> design for hot <span class="hlt">air</span> ericsson-brayton piston engine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ďurčanský, P.; Lenhard, R.; Jandačka, J.</p> <p>2014-03-01</p> <p>One of the solutions without negative consequences for the increasing energy consumption in the world may be use of alternative energy sources in micro-cogeneration. Currently it is looking for different solutions and there are many possible ways. Cogeneration is known for long time and is widely used. But the installations are often large and the installed output is more suitable for cities or industry companies. When we will speak about decentralization, the small machines have to be used. The article deals with the principle of hot-<span class="hlt">air</span> engines, their use in combined heat and electricity production from biomass and with heat <span class="hlt">exchangers</span> as primary energy transforming element. In the article is hot <span class="hlt">air</span> engine presented as a heat engine that allows the conversion of heat into mechanical energy while heat supply can be external. In the contribution are compared cycles of hot-<span class="hlt">air</span> engine. Then are compared suitable heat <span class="hlt">exchangers</span> for use with hot <span class="hlt">air</span> Ericsson-Brayton engine. In the final part is proposal of heat <span class="hlt">exchanger</span> for use in closed Ericsson-Brayton cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1341440','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1341440"><span>Advanced Heat/<span class="hlt">Mass</span> <span class="hlt">Exchanger</span> Technology for Geothermal and Solar Renewable Energy Systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Greiner, Miles; Childress, Amy; Hiibel, Sage</p> <p>2014-12-16</p> <p>Northern Nevada has abundant geothermal and solar energy resources, and these renewable energy sources provide an ample opportunity to produce economically viable power. Heat/<span class="hlt">mass</span> <span class="hlt">exchangers</span> are essential components to any energy conversion system. Improvements in the heat/<span class="hlt">mass</span> <span class="hlt">exchange</span> process will lead to smaller, less costly (more efficient) systems. There is an emerging heat transfer technology, based on micro/nano/molecular-scale surface science that can be applied to heat/<span class="hlt">mass</span> <span class="hlt">exchanger</span> design. The objective is to develop and characterize unique coating materials, surface configurations and membranes capable of accommodating a 10-fold increase in heat/<span class="hlt">mass</span> <span class="hlt">exchanger</span> performance via phase change processes (boiling, condensation, etc.) andmore » single phase convective heat/<span class="hlt">mass</span> transfer.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26642083','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26642083"><span>Gaseous and Freely-Dissolved PCBs in the Lower Great Lakes Based on Passive Sampling: Spatial Trends and <span class="hlt">Air</span>-Water <span class="hlt">Exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Ying; Wang, Siyao; McDonough, Carrie A; Khairy, Mohammed; Muir, Derek C G; Helm, Paul A; Lohmann, Rainer</p> <p>2016-05-17</p> <p>Polyethylene passive sampling was performed to quantify gaseous and freely dissolved polychlorinated biphenyls (PCBs) in the <span class="hlt">air</span> and water of Lakes Erie and Ontario during 2011-2012. In view of differing physical characteristics and the impacts of historical contamination by PCBs within these lakes, spatial variation of PCB concentrations and <span class="hlt">air</span>-water <span class="hlt">exchange</span> across these lakes may be expected. Both lakes displayed statistically similar aqueous and atmospheric PCB concentrations. Total aqueous concentrations of 29 PCBs ranged from 1.5 pg L(-1) in the open lake of Lake Erie (site E02) in 2011 spring to 105 pg L(-1) in Niagara (site On05) in 2012 summer, while total atmospheric concentrations were 7.7-634 pg m(-3) across both lakes. A west-to-east gradient was observed for aqueous PCBs in Lake Erie. River discharge and localized influences (e.g., sediment resuspension and regional alongshore transport) likely dominated spatial trends of aqueous PCBs in both lakes. <span class="hlt">Air</span>-water <span class="hlt">exchange</span> fluxes of Σ7PCBs ranged from -2.4 (±1.9) ng m(-2) day(-1) (deposition) in Sheffield (site E03) to 9.0 (±3.1) ng m(-2) day(-1) (volatilization) in Niagara (site On05). Net volatilization of PCBs was the primary trend across most sites and periods. Almost half of variation in <span class="hlt">air</span>-water <span class="hlt">exchange</span> fluxes was attributed to the difference in aqueous concentrations of PCBs. Uncertainty analysis in fugacity ratios and <span class="hlt">mass</span> fluxes in <span class="hlt">air</span>-water <span class="hlt">exchange</span> of PCBs indicated that PCBs have reached or approached equilibrium only at the eastern Lake Erie and along the Canadian shore of Lake Ontario sites, where <span class="hlt">air</span>-water <span class="hlt">exchange</span> fluxes dominated atmospheric concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21141036','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21141036"><span>Advances in quantifying <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> and environmental forcing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wanninkhof, Rik; Asher, William E; Ho, David T; Sweeney, Colm; McGillis, Wade R</p> <p>2009-01-01</p> <p>The past decade has seen a substantial amount of research on <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> and its environmental controls. These studies have significantly advanced the understanding of processes that control gas transfer, led to higher quality field measurements, and improved estimates of the flux of climate-relevant gases between the ocean and atmosphere. This review discusses the fundamental principles of <span class="hlt">air</span>-sea gas transfer and recent developments in gas transfer theory, parameterizations, and measurement techniques in the context of the <span class="hlt">exchange</span> of carbon dioxide. However, much of this discussion is applicable to any sparingly soluble, non-reactive gas. We show how the use of global variables of environmental forcing that have recently become available and gas <span class="hlt">exchange</span> relationships that incorporate the main forcing factors will lead to improved estimates of global and regional <span class="hlt">air</span>-sea gas fluxes based on better fundamental physical, chemical, and biological foundations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=197971&Lab=NERL&keyword=gas+AND+behaviour&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=197971&Lab=NERL&keyword=gas+AND+behaviour&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Simulating the Vapour Phase <span class="hlt">Air</span>/Water <span class="hlt">Exchange</span> of p,p′-DDE, p,p′-DDT, Lindane, and 2,3,7,8-Tetrachlorodibenzodioxin</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Uncertainties in our understanding of gaseous <span class="hlt">air</span>/water <span class="hlt">exchange</span> have emerged as major sources of concern in efforts to construct global and regional <span class="hlt">mass</span> balances of both the green house gas carbon dioxide and semi-volatile persistent, bioaccumulative and toxic chemicals. Hoff e...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12214652','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12214652"><span>Exposure chamber measurements of <span class="hlt">mass</span> transfer and partitioning at the plant/<span class="hlt">air</span> interface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maddalena, Randy L; McKone, Thomas E; Kado, Norman Y</p> <p>2002-08-15</p> <p>Dynamic measures of <span class="hlt">air</span> and vegetation concentrations in an exposure chamber and a two-box <span class="hlt">mass</span> balance model are used to quantify factors that control the rate and extent of chemical partitioning between vegetation and the atmosphere. A continuous stirred flow-through exposure chamber was used to investigate the gas-phase transfer of pollutants between <span class="hlt">air</span> and plants. A probabilistic two-compartment <span class="hlt">mass</span> balance model of plant/<span class="hlt">air</span> <span class="hlt">exchange</span> within the exposure chamber was developed and used with measured concentrations from the chamber to simultaneously evaluate partitioning (Kpa), overall <span class="hlt">mass</span> transfer across the plant/<span class="hlt">air</span> interface (Upa), and loss rates in the atmosphere (Ra) and aboveground vegetation (Rp). The approach is demonstrated using mature Capsicum annuum (bell pepper) plants exposed to phenanthrene (PH), anthracene (AN), fluoranthene (FL) and pyrene (PY). Measured values of log Kpa (V[<span class="hlt">air</span>]/V[fresh plant]) were 5.7, 5.7, 6.0, and 6.2 for PH, AN, FL, and PY, respectively. Values of Upa (m d(-1)) under the conditions of this study ranged from 42 for PH to 119 for FL. After correcting for wall effects, the estimated reaction half-lives in <span class="hlt">air</span> were 3, 9, and 25 h for AN, FL and PY. Reaction half-lives in the plant compartment were 17, 6, 17, and 5 d for PH, AN, FL, and PY, respectively. The combined use of exposure chamber measurements and models provides a robust tool for simultaneously measuring several different transfer factors that are important for modeling the uptake of pollutants into vegetation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22965280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22965280"><span>Minimizing back <span class="hlt">exchange</span> in the hydrogen <span class="hlt">exchange-mass</span> spectrometry experiment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walters, Benjamin T; Ricciuti, Alec; Mayne, Leland; Englander, S Walter</p> <p>2012-12-01</p> <p>The addition of <span class="hlt">mass</span> spectrometry (MS) analysis to the hydrogen <span class="hlt">exchange</span> (HX) proteolytic fragmentation experiment extends powerful HX methodology to the study of large biologically important proteins. A persistent problem is the degradation of HX information due to back <span class="hlt">exchange</span> of deuterium label during the fragmentation-separation process needed to prepare samples for MS measurement. This paper reports a systematic analysis of the factors that influence back <span class="hlt">exchange</span> (solution pH, ionic strength, desolvation temperature, LC column interaction, flow rates, system volume). The many peptides exhibit a range of back <span class="hlt">exchange</span> due to intrinsic amino acid HX rate differences. Accordingly, large back <span class="hlt">exchange</span> leads to large variability in D-recovery from one residue to another as well as one peptide to another that cannot be corrected for by reference to any single peptide-level measurement. The usual effort to limit back <span class="hlt">exchange</span> by limiting LC time provides little gain. Shortening the LC elution gradient by 3-fold only reduced back <span class="hlt">exchange</span> by ~2%, while sacrificing S/N and peptide count. An unexpected dependence of back <span class="hlt">exchange</span> on ionic strength as well as pH suggests a strategy in which solution conditions are changed during sample preparation. Higher salt should be used in the first stage of sample preparation (proteolysis and trapping) and lower salt (<20 mM) and pH in the second stage before electrospray injection. Adjustment of these and other factors together with recent advances in peptide fragment detection yields hundreds of peptide fragments with D-label recovery of 90% ± 5%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JASMS..23.2132W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JASMS..23.2132W"><span>Minimizing Back <span class="hlt">Exchange</span> in the Hydrogen <span class="hlt">Exchange-Mass</span> Spectrometry Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walters, Benjamin T.; Ricciuti, Alec; Mayne, Leland; Englander, S. Walter</p> <p>2012-12-01</p> <p>The addition of <span class="hlt">mass</span> spectrometry (MS) analysis to the hydrogen <span class="hlt">exchange</span> (HX) proteolytic fragmentation experiment extends powerful HX methodology to the study of large biologically important proteins. A persistent problem is the degradation of HX information due to back <span class="hlt">exchange</span> of deuterium label during the fragmentation-separation process needed to prepare samples for MS measurement. This paper reports a systematic analysis of the factors that influence back <span class="hlt">exchange</span> (solution pH, ionic strength, desolvation temperature, LC column interaction, flow rates, system volume). The many peptides exhibit a range of back <span class="hlt">exchange</span> due to intrinsic amino acid HX rate differences. Accordingly, large back <span class="hlt">exchange</span> leads to large variability in D-recovery from one residue to another as well as one peptide to another that cannot be corrected for by reference to any single peptide-level measurement. The usual effort to limit back <span class="hlt">exchange</span> by limiting LC time provides little gain. Shortening the LC elution gradient by 3-fold only reduced back <span class="hlt">exchange</span> by ~2 %, while sacrificing S/N and peptide count. An unexpected dependence of back <span class="hlt">exchange</span> on ionic strength as well as pH suggests a strategy in which solution conditions are changed during sample preparation. Higher salt should be used in the first stage of sample preparation (proteolysis and trapping) and lower salt (<20 mM) and pH in the second stage before electrospray injection. Adjustment of these and other factors together with recent advances in peptide fragment detection yields hundreds of peptide fragments with D-label recovery of 90 % ± 5 %.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27461227','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27461227"><span><span class="hlt">Air</span> breathing and aquatic gas <span class="hlt">exchange</span> during hypoxia in armoured catfish.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scott, Graham R; Matey, Victoria; Mendoza, Julie-Anne; Gilmour, Kathleen M; Perry, Steve F; Almeida-Val, Vera M F; Val, Adalberto L</p> <p>2017-01-01</p> <p><span class="hlt">Air</span> breathing in fish is commonly believed to have arisen as an adaptation to aquatic hypoxia. The effectiveness of <span class="hlt">air</span> breathing for tissue O 2 supply depends on the ability to avoid O 2 loss as oxygenated blood from the <span class="hlt">air</span>-breathing organ passes through the gills. Here, we evaluated whether the armoured catfish (Hypostomus aff. pyreneusi)-a facultative <span class="hlt">air</span> breather-can avoid branchial O 2 loss while <span class="hlt">air</span> breathing in aquatic hypoxia, and we measured various other respiratory and metabolic traits important for O 2 supply and utilization. Fish were instrumented with opercular catheters to measure the O 2 tension (PO 2 ) of expired water, and <span class="hlt">air</span> breathing and aquatic respiration were measured during progressive stepwise hypoxia in the water. Armoured catfish exhibited relatively low rates of O 2 consumption and gill ventilation, and gill ventilation increased in hypoxia due primarily to increases in ventilatory stroke volume. Armoured catfish began <span class="hlt">air</span> breathing at a water PO 2 of 2.5 kPa, and both <span class="hlt">air</span>-breathing frequency and hypoxia tolerance (as reflected by PO 2 at loss of equilibrium, LOE) was greater in individuals with a larger body <span class="hlt">mass</span>. Branchial O 2 loss, as reflected by higher PO 2 in expired than in inspired water, was observed in a minority (4/11) of individuals as water PO 2 approached that at LOE. Armoured catfish also exhibited a gill morphology characterized by short filaments bearing short fused lamellae, large interlamellar cell <span class="hlt">masses</span>, low surface area, and a thick epithelium that increased water-to-blood diffusion distance. Armoured catfish had a relatively low blood-O 2 binding affinity when sampled in normoxia (P 50 of 3.1 kPa at pH 7.4), but were able to rapidly increase binding affinity during progressive hypoxia exposure (to a P 50 of 1.8 kPa). Armoured catfish also had low activities of several metabolic enzymes in white muscle, liver, and brain. Therefore, low rates of metabolism and gill ventilation, and a reduction in branchial gas-<span class="hlt">exchange</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5228218','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5228218"><span>Impacts of Changes of Indoor <span class="hlt">Air</span> Pressure and <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rate in Vapor Intrusion Scenarios</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shen, Rui; Suuberg, Eric M.</p> <p>2016-01-01</p> <p>There has, in recent years, been increasing interest in understanding the transport processes of relevance in vapor intrusion of volatile organic compounds (VOCs) into buildings on contaminated sites. These studies have included fate and transport modeling. Most such models have simplified the prediction of indoor <span class="hlt">air</span> contaminant vapor concentrations by employing a steady state assumption, which often results in difficulties in reconciling these results with field measurements. This paper focuses on two major factors that may be subject to significant transients in vapor intrusion situations, including the indoor <span class="hlt">air</span> pressure and the <span class="hlt">air</span> <span class="hlt">exchange</span> rate in the subject building. A three-dimensional finite element model was employed with consideration of daily and seasonal variations in these factors. From the results, the variations of indoor <span class="hlt">air</span> pressure and <span class="hlt">air</span> <span class="hlt">exchange</span> rate are seen to contribute to significant variations in indoor <span class="hlt">air</span> contaminant vapor concentrations. Depending upon the assumptions regarding the variations in these parameters, the results are only sometimes consistent with the reports of several orders of magnitude in indoor <span class="hlt">air</span> concentration variations from field studies. The results point to the need to examine more carefully the interplay of these factors in order to quantitatively understand the variations in potential indoor <span class="hlt">air</span> exposures. PMID:28090133</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28090133','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28090133"><span>Impacts of Changes of Indoor <span class="hlt">Air</span> Pressure and <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rate in Vapor Intrusion Scenarios.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, Rui; Suuberg, Eric M</p> <p>2016-02-01</p> <p>There has, in recent years, been increasing interest in understanding the transport processes of relevance in vapor intrusion of volatile organic compounds (VOCs) into buildings on contaminated sites. These studies have included fate and transport modeling. Most such models have simplified the prediction of indoor <span class="hlt">air</span> contaminant vapor concentrations by employing a steady state assumption, which often results in difficulties in reconciling these results with field measurements. This paper focuses on two major factors that may be subject to significant transients in vapor intrusion situations, including the indoor <span class="hlt">air</span> pressure and the <span class="hlt">air</span> <span class="hlt">exchange</span> rate in the subject building. A three-dimensional finite element model was employed with consideration of daily and seasonal variations in these factors. From the results, the variations of indoor <span class="hlt">air</span> pressure and <span class="hlt">air</span> <span class="hlt">exchange</span> rate are seen to contribute to significant variations in indoor <span class="hlt">air</span> contaminant vapor concentrations. Depending upon the assumptions regarding the variations in these parameters, the results are only sometimes consistent with the reports of several orders of magnitude in indoor <span class="hlt">air</span> concentration variations from field studies. The results point to the need to examine more carefully the interplay of these factors in order to quantitatively understand the variations in potential indoor <span class="hlt">air</span> exposures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16508435','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16508435"><span>Retinal damage caused by <span class="hlt">air</span>-fluid <span class="hlt">exchange</span> during pars plana vitrectomy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Sam S; McDonald, H Richard; Everett, A I; Johnson, Robert N; Jumper, J Michael; Fu, Arthur D</p> <p>2006-03-01</p> <p>To report two cases of retinal damage associated with <span class="hlt">air</span> infusion during pars plana vitrectomy. Observational case report. The authors reviewed the course of two patients who had retinal damage during par plana vitrectomy and <span class="hlt">air</span>-fluid <span class="hlt">exchange</span> for the treatment of macular hole and optic pit-related macular detachment, respectively. The intraoperative observations, postoperative course, and outcomes were reported. As a result of high <span class="hlt">air</span> infusion flow during <span class="hlt">air</span>-fluid <span class="hlt">exchange</span>, retinal damage was created in the area contralateral to the infusion port. In Case 1, an oval area of whitening was noted on the first postoperative day. This area subsequently developed into a large retinal break associated with retinal detachment. In the second case, retinal whitening was noted intraoperatively. This region of pallor resolved quickly during the early postoperative period but resulted in a corresponding inferotemporal visual field defect. High infusion flow during <span class="hlt">air</span>-fluid <span class="hlt">exchange</span> in eyes undergoing vitrectomy surgery may result in significant retinal damage. This pressure-induced trauma initially causes retinal whitening that may be seen intraoperatively or during the early postoperative period. The region of damaged retina may develop a retinal break and detachment or a corresponding visual field defect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10970675','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10970675"><span>Turbulence and wave breaking effects on <span class="hlt">air</span>-water gas <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boettcher; Fineberg; Lathrop</p> <p>2000-08-28</p> <p>We present an experimental characterization of the effects of turbulence and breaking gravity waves on <span class="hlt">air</span>-water gas <span class="hlt">exchange</span> in standing waves. We identify two regimes that govern aeration rates: turbulent transport when no wave breaking occurs and bubble dominated transport when wave breaking occurs. In both regimes, we correlate the qualitative changes in the aeration rate with corresponding changes in the wave dynamics. In the latter regime, the strongly enhanced aeration rate is correlated with measured acoustic emissions, indicating that bubble creation and dynamics dominate <span class="hlt">air</span>-water <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25597683','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25597683"><span><span class="hlt">Air</span>-soil <span class="hlt">exchange</span> of organochlorine pesticides in a sealed chamber.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Bing; Han, Baolu; Xue, Nandong; Zhou, Lingli; Li, Fasheng</p> <p>2015-01-01</p> <p>So far little is known about <span class="hlt">air</span>-soil <span class="hlt">exchange</span> under any sealed circumstances (e.g., in plastic and glass sheds), which however has huge implications for the soil-<span class="hlt">air</span>-plant pathways of persistent organic pollutants including organochlorine pesticides (OCPs). A newly designed passive <span class="hlt">air</span> sampler was tested in a sealed chamber for measuring the vertical concentration profiles of gaseous phase OCPs (hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs)). <span class="hlt">Air</span> was sampled at 5, 15, and 30 cm above ground level every 10th day during a 60-day period by deploying polyurethane foam cylinders housed in acrylonitrile butadiene styrene-covered cartridges. Concentrations and compositions of OCPs along the vertical sections indicated a clear relationship with proximity to the mixture of HCHs and DDTs which escapes from the soils. In addition, significant positive correlations were found between <span class="hlt">air</span> temperatures and concentrations of HCHs and DDTs. These results indicated revolatilization and re-deposition being at or close to dynamic pseudo-equilibrium with the overlying <span class="hlt">air</span>. The sampler used for addressing <span class="hlt">air</span>-soil <span class="hlt">exchange</span> of persistent organic pollutants in any sealed conditions is discussed. Copyright © 2014. Published by Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19778365','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19778365"><span>Why and how terrestrial plants <span class="hlt">exchange</span> gases with <span class="hlt">air</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cieslik, S; Omasa, K; Paoletti, E</p> <p>2009-11-01</p> <p>This work is intended as a review of gas <span class="hlt">exchange</span> processes between the atmosphere and the terrestrial vegetation, which have been known for more than two centuries since the discovery of photosynthesis. The physical and biological mechanisms of <span class="hlt">exchange</span> of carbon dioxide, water vapour, volatile organic compounds emitted by plants and <span class="hlt">air</span> pollutants taken up by them, is critically reviewed. The role of stomatal physiology is emphasised, as it controls most of these processes. The techniques used for measurement of gas <span class="hlt">exchange</span> fluxes between the atmosphere and vegetation are outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17664033','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17664033"><span>Carbon source/sink function of a subtropical, eutrophic lake determined from an overall <span class="hlt">mass</span> balance and a gas <span class="hlt">exchange</span> and carbon burial balance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Hong; Xing, Yangping; Xie, Ping; Ni, Leyi; Rong, Kewen</p> <p>2008-02-01</p> <p>Although studies on carbon burial in lake sediments have shown that lakes are disproportionately important carbon sinks, many studies on gaseous carbon <span class="hlt">exchange</span> across the water-<span class="hlt">air</span> interface have demonstrated that lakes are supersaturated with CO(2) and CH(4) causing a net release of CO(2) and CH(4) to the atmosphere. In order to more accurately estimate the net carbon source/sink function of lake ecosystems, a more comprehensive carbon budget is needed, especially for gaseous carbon <span class="hlt">exchange</span> across the water-<span class="hlt">air</span> interface. Using two methods, overall <span class="hlt">mass</span> balance and gas <span class="hlt">exchange</span> and carbon burial balance, we assessed the carbon source/sink function of Lake Donghu, a subtropical, eutrophic lake, from April 2003 to March 2004. With the overall <span class="hlt">mass</span> balance calculations, total carbon input was 14 905 t, total carbon output was 4950 t, and net carbon budget was +9955 t, suggesting that Lake Donghu was a great carbon sink. For the gas <span class="hlt">exchange</span> and carbon burial balance, gaseous carbon (CO(2) and CH(4)) emission across the water-<span class="hlt">air</span> interface totaled 752 t while carbon burial in the lake sediment was 9477 t. The ratio of carbon emission into the atmosphere to carbon burial into the sediment was only 0.08. This low ratio indicates that Lake Donghu is a great carbon sink. Results showed good agreement between the two methods with both showing Lake Donghu to be a great carbon sink. This results from the high primary production of Lake Donghu, substantive allochthonous carbon inputs and intensive anthropogenic activity. Gaseous carbon emission accounted for about 15% of the total carbon output, indicating that the total output would be underestimated without including gaseous carbon <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15914236','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15914236"><span>Passive <span class="hlt">air</span> sampling theory for semivolatile organic compounds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bartkow, Michael E; Booij, Kees; Kennedy, Karen E; Müller, Jochen F; Hawker, Darryl W</p> <p>2005-07-01</p> <p>The mathematical modelling underlying passive <span class="hlt">air</span> sampling theory can be based on <span class="hlt">mass</span> transfer coefficients or rate constants. Generally, these models have not been inter-related. Starting with basic models, the <span class="hlt">exchange</span> of chemicals between the gaseous phase and the sampler is developed using <span class="hlt">mass</span> transfer coefficients and rate constants. Importantly, the inter-relationships between the approaches are demonstrated by relating uptake rate constants and loss rate constants to <span class="hlt">mass</span> transfer coefficients when either sampler-side or <span class="hlt">air</span>-side resistance is dominating chemical <span class="hlt">exchange</span>. The influence of sampler area and sampler volume on chemical <span class="hlt">exchange</span> is discussed in general terms and as they relate to frequently used parameters such as sampling rates and time to equilibrium. Where <span class="hlt">air</span>-side or sampler-side resistance dominates, an increase in the surface area of the sampler will increase sampling rates. Sampling rates are not related to the sampler/<span class="hlt">air</span> partition coefficient (K(SV)) when <span class="hlt">air</span>-side resistance dominates and increase with K(SV) when sampler-side resistance dominates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.3367R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.3367R"><span><span class="hlt">Air</span> Circulation and Heat <span class="hlt">Exchange</span> under Reduced Pressures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rygalov, Vadim; Wheeler, Raymond; Dixon, Mike; Hillhouse, Len; Fowler, Philip</p> <p></p> <p>Low pressure atmospheres were suggested for Space Greenhouses (SG) design to minimize sys-tem construction and re-supply materials, as well as system manufacturing and deployment costs. But rarified atmospheres modify heat <span class="hlt">exchange</span> mechanisms what finally leads to alter-ations in thermal control for low pressure closed environments. Under low atmospheric pressures (e.g., lower than 25 kPa compare to 101.3 kPa for normal Earth atmosphere), convection is becoming replaced by diffusion and rate of heat <span class="hlt">exchange</span> reduces significantly. During a period from 2001 to 2009, a series of hypobaric experiments were conducted at Space Life Sciences Lab (SLSLab) NASA's Kennedy Space Center and the Department of Space Studies, University of North Dakota. Findings from these experiments showed: -<span class="hlt">air</span> circulation rate decreases non-linearly with lowering of total atmospheric pressure; -heat <span class="hlt">exchange</span> slows down with pressure decrease creating risk of thermal stress (elevated leaf tem-peratures) for plants in closed environments; -low pressure-induced thermal stress could be reduced by either lowering system temperature set point or increasing forced convection rates (circulation fan power) within certain limits; <span class="hlt">Air</span> circulation is an important constituent of controlled environments and plays crucial role in material and heat <span class="hlt">exchange</span>. Theoretical schematics and mathematical models are developed from a series of observations. These models can be used to establish optimal control algorithms for low pressure environments, such as a space greenhouse, as well as assist in fundamental design concept developments for these or similar habitable structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=261773&keyword=Human+AND+interaction&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=261773&keyword=Human+AND+interaction&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Spatiotemporally‐Resolved <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rate as a Modifier of Acute <span class="hlt">Air</span> Pollution‐Related Morbidity in AtlantaMorbidity in Atlanta</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Epidemiological studies frequently use central site concentrations as surrogates of exposure to <span class="hlt">air</span> pollutants. Variability in <span class="hlt">air</span> pollutant infiltration due to differential <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AERs) is potentially a major factor affecting the relationship between central site c...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Inertia&pg=5&id=EJ876095','ERIC'); return false;" href="https://eric.ed.gov/?q=Inertia&pg=5&id=EJ876095"><span>The Effective <span class="hlt">Mass</span> of a Ball in the <span class="hlt">Air</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Messer, J.; Pantaleone, J.</p> <p>2010-01-01</p> <p>The <span class="hlt">air</span> surrounding a projectile affects the projectile's motion in three very different ways: the drag force, the buoyant force, and the added <span class="hlt">mass</span>. The added <span class="hlt">mass</span> is an increase in the projectile's inertia from the motion of the <span class="hlt">air</span> around it. Here we experimentally measure the added <span class="hlt">mass</span> of a spherical projectile in <span class="hlt">air</span>. The results agree well…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3427778','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3427778"><span>Hydrogen <span class="hlt">Exchange</span> and <span class="hlt">Mass</span> Spectrometry: A Historical Perspective</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Englander, S. Walter</p> <p>2012-01-01</p> <p>Protein molecules naturally emit streams of information-rich signals in the language of hydrogen <span class="hlt">exchange</span> concerning the intimate details of their stability, dynamics, function, changes therein, and effects thereon, all resolved to the level of their individual amino acids. The effort to measure protein hydrogen <span class="hlt">exchange</span> behavior, understand the underlying chemistry and structural physics of hydrogen <span class="hlt">exchange</span> processes, and use this information to learn about protein properties and function has continued for 50 years. Recent work uses <span class="hlt">mass</span> spectrometric analysis together with an earlier proteolytic fragmentation method to extend the hydrogen <span class="hlt">exchange</span> capability to large biologically interesting proteins. This article briefly reviews the advances that have led us to this point and the understanding that has so far been achieved. PMID:16876429</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1255696-low-gwp-refrigerants-modelling-study-room-air-conditioner-having-microchannel-heat-exchangers','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1255696-low-gwp-refrigerants-modelling-study-room-air-conditioner-having-microchannel-heat-exchangers"><span>Low GWP Refrigerants Modelling Study for a Room <span class="hlt">Air</span> Conditioner Having Microchannel Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Shen, Bo; Bhandari, Mahabir S</p> <p></p> <p>Microchannel heat <span class="hlt">exchangers</span> (MHX) have found great successes in residential and commercial <span class="hlt">air</span> conditioning applications, being compact heat <span class="hlt">exchangers</span>, to reduce refrigerant charge and material cost. This investigation aims to extend the application of MHXs in split, room <span class="hlt">air</span> conditioners (RAC), per fundamental heat <span class="hlt">exchanger</span> and system modelling. For this paper, microchannel condenser and evaporator models were developed, using a segment-to-segment modelling approach. The microchannel heat <span class="hlt">exchanger</span> models were integrated to a system design model. The system model is able to predict the performance indices, such as cooling capacity, efficiency, sensible heat ratio, etc. Using the calibrated system and heatmore » <span class="hlt">exchanger</span> models, we evaluated numerous low GWP (global warming potential) refrigerants. The predicted system performance indices, e.g. cooling efficiency, compressor discharge temperature, and required compressor displacement volume etc., are compared. Suitable replacements for R22 and R-410A for the room <span class="hlt">air</span> conditioner application are recommended.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840011675','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840011675"><span>Hydromechanics and heat and <span class="hlt">mass</span> <span class="hlt">exchange</span> in weightlessness (Russian book): Table of contents</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Avduyevskiy, V. S.; Poleshayev, V. I.</p> <p>1983-01-01</p> <p>The table of contents is given for a book on hydromechanics and heat and <span class="hlt">mass</span> <span class="hlt">exchange</span> in weightlessness. The book covers such subjects as hydromechanics, convection and heat and <span class="hlt">mass</span> <span class="hlt">exchange</span>, and technological experiments and complicated systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1953j0089J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1953j0089J"><span>Experimental temperature analysis of simple & hybrid earth <span class="hlt">air</span> tunnel heat <span class="hlt">exchanger</span> in series connection at Bikaner Rajasthan India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jakhar, O. P.; Sharma, Chandra Shekhar; Kukana, Rajendra</p> <p>2018-05-01</p> <p>The Earth <span class="hlt">Air</span> Tunnel Heat <span class="hlt">Exchanger</span> System is a passive <span class="hlt">air</span>-conditioning system which has no side effect on earth climate and produces better cooling effect and heating effect comfortable to human body. It produces heating effect in winter and cooling effect in summer with the minimum power consumption of energy as compare to other <span class="hlt">air</span>-conditioning devices. In this research paper Temperature Analysis was done on the two systems of Earth <span class="hlt">Air</span> Tunnel Heat <span class="hlt">Exchanger</span> experimentally for summer cooling purpose. Both the system was installed at Mechanical Engineering Department Government Engineering College Bikaner Rajasthan India. Experimental results concludes that the Average <span class="hlt">Air</span> Temperature Difference was found as 11.00° C and 16.27° C for the Simple and Hybrid Earth <span class="hlt">Air</span> Tunnel Heat <span class="hlt">Exchanger</span> in Series Connection System respectively. The Maximum <span class="hlt">Air</span> Temperature Difference was found as 18.10° C and 23.70° C for the Simple and Hybrid Earth <span class="hlt">Air</span> Tunnel Heat <span class="hlt">Exchanger</span> in Series Connection System respectively. The Minimum <span class="hlt">Air</span> Temperature Difference was found as 5.20° C and 11.70° C for the Simple and Hybrid Earth <span class="hlt">Air</span> Tunnel Heat <span class="hlt">Exchanger</span> in Series Connection System respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25309638','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25309638"><span>SAIDE: A Semi-Automated Interface for Hydrogen/Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Villar, Maria T; Miller, Danny E; Fenton, Aron W; Artigues, Antonio</p> <p>2010-01-01</p> <p>Deuterium/hydrogen <span class="hlt">exchange</span> in combination with <span class="hlt">mass</span> spectrometry (DH MS) is a sensitive technique for detection of changes in protein conformation and dynamics. Since temperature, pH and timing control are the key elements for reliable and efficient measurement of hydrogen/deuterium content in proteins and peptides, we have developed a small, semiautomatic interface for deuterium <span class="hlt">exchange</span> that interfaces the HPLC pumps with a <span class="hlt">mass</span> spectrometer. This interface is relatively inexpensive to build, and provides efficient temperature and timing control in all stages of enzyme digestion, HPLC separation and <span class="hlt">mass</span> analysis of the resulting peptides. We have tested this system with a series of standard tryptic peptides reconstituted in a solvent containing increasing concentration of deuterium. Our results demonstrate the use of this interface results in minimal loss of deuterium due to back <span class="hlt">exchange</span> during HPLC desalting and separation. For peptides reconstituted in a buffer containing 100% deuterium, and assuming that all amide linkages have <span class="hlt">exchanged</span> hydrogen with deuterium, the maximum loss of deuterium content is only 17% of the label, indicating the loss of only one deuterium molecule per peptide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4192651','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4192651"><span>SAIDE: A Semi-Automated Interface for Hydrogen/Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Villar, Maria T.; Miller, Danny E.; Fenton, Aron W.; Artigues, Antonio</p> <p>2011-01-01</p> <p>Deuterium/hydrogen <span class="hlt">exchange</span> in combination with <span class="hlt">mass</span> spectrometry (DH MS) is a sensitive technique for detection of changes in protein conformation and dynamics. Since temperature, pH and timing control are the key elements for reliable and efficient measurement of hydrogen/deuterium content in proteins and peptides, we have developed a small, semiautomatic interface for deuterium <span class="hlt">exchange</span> that interfaces the HPLC pumps with a <span class="hlt">mass</span> spectrometer. This interface is relatively inexpensive to build, and provides efficient temperature and timing control in all stages of enzyme digestion, HPLC separation and <span class="hlt">mass</span> analysis of the resulting peptides. We have tested this system with a series of standard tryptic peptides reconstituted in a solvent containing increasing concentration of deuterium. Our results demonstrate the use of this interface results in minimal loss of deuterium due to back <span class="hlt">exchange</span> during HPLC desalting and separation. For peptides reconstituted in a buffer containing 100% deuterium, and assuming that all amide linkages have <span class="hlt">exchanged</span> hydrogen with deuterium, the maximum loss of deuterium content is only 17% of the label, indicating the loss of only one deuterium molecule per peptide. PMID:25309638</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20000740-coupling-phytoplankton-uptake-air-water-exchange-persistent-organic-pollutants','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20000740-coupling-phytoplankton-uptake-air-water-exchange-persistent-organic-pollutants"><span>Coupling of phytoplankton uptake and <span class="hlt">air</span>-water <span class="hlt">exchange</span> of persistent organic pollutants</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dachs, J.; Eisenreich, S.J.; Baker, J.E.</p> <p>1999-10-15</p> <p>A dynamic model that couples <span class="hlt">air</span>-water <span class="hlt">exchange</span> and phytoplankton uptake of persistent organic pollutants has been developed and then applied to PCB data from a small experimental lake. A sensitivity analysis of the model, taking into account the influence of physical environmental conditions such as temperature, wind speed, and mixing depth as well as plankton-related parameters such as biomass and growth rate was carried out for a number of PCBs with different physical-chemical properties. The results indicate that <span class="hlt">air</span>-water <span class="hlt">exchange</span> dynamics are influenced not only by physical parameters but also by phytoplankton biomass and growth rate. New phytoplankton production resultsmore » in substantially longer times to reach equilibrium. Phytoplankton uptake-induced depletion of the dissolved phase concentration maintains <span class="hlt">air</span> and water phases out of equilibrium. Furthermore, PCBs in phytoplankton also take longer times to reach equilibrium with the dissolved water phase when the latter is supported by diffusive <span class="hlt">air</span>-water <span class="hlt">exchange</span>. However, both model analysis and model application to the Experimental Lakes Area of northwestern Ontario (Canada) suggest that the gas phase supports the concentrations of persistent organic pollutants, such as PCBs, in atmospherically driven aquatic environments.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=335530&Lab=NERL&keyword=smith&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=335530&Lab=NERL&keyword=smith&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Probabilistic estimation of residential <span class="hlt">air</span> <span class="hlt">exchange</span> rates for population-based human exposure modeling</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Residential <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AERs) are a key determinant in the infiltration of ambient <span class="hlt">air</span> pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to <span class="hlt">air</span> pollutants have relied on input distributions from AER meas...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E3SWC..2200027C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E3SWC..2200027C"><span>Industrial applications of the <span class="hlt">air</span> direct-contact, gravel, ground heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cepiński, Wojciech; Besler, Maciej</p> <p>2017-11-01</p> <p>The paper describes the analysis of possibility of using the <span class="hlt">air</span> direct-contact, gravel, ground heat <span class="hlt">exchanger</span> (Polish acronym BGWCiM), patented at the Wroclaw University of Science and Technology to prepare <span class="hlt">air</span> for conditioning rooms in the industry. Indicated the industry sectors where the application may be the most beneficial.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59799&keyword=Exchange+AND+gaseous&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59799&keyword=Exchange+AND+gaseous&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>THE EFFECT OF SALINITY ON RATES OF ELEMENTAL MERCURY <span class="hlt">AIR</span>/WATER <span class="hlt">EXCHANGE</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The U.S. EPA laboratory in Athens, Georgia i spursuing the goal of developing a model for describing toxicant vapor phase <span class="hlt">air</span>/water <span class="hlt">exchange</span> under all relevant environmental conditions. To date, the two-layer <span class="hlt">exchange</span> model (suitable for low wind speed conditions) has been modif...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25686886','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25686886"><span>The effects of rice canopy on the <span class="hlt">air</span>-soil <span class="hlt">exchange</span> of polycyclic aromatic hydrocarbons and organochlorine pesticides using paired passive <span class="hlt">air</span> samplers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yan; Wang, Shaorui; Luo, Chunling; Li, Jun; Ming, Lili; Zhang, Gan; Li, Xiangdong</p> <p>2015-05-01</p> <p>The rice canopy in paddy fields can influence the <span class="hlt">air</span>-soil <span class="hlt">exchange</span> of organic chemicals. We used paired passive <span class="hlt">air</span> samplers to assess the <span class="hlt">exchange</span> of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in a paddy field, South China. Levels of OCPs and light PAHs were generally higher under the canopy than above it. We found that the rice canopy can physically obstruct the evaporation of most OCPs and light PAHs, and can also act as a barrier to the gaseous deposition of p,p'-DDT and heavy PAHs. Paddy fields can behave as a secondary source of OCPs and light PAHs. The homolog patterns of these two types of chemical varied slightly between the <span class="hlt">air</span> below and above the rice canopy, implying contributions of different sources. Paired passive <span class="hlt">air</span> samplers can be used effectively to assess the in situ <span class="hlt">air</span>-soil <span class="hlt">exchange</span> of PAHs and OCPs in subtropical paddy fields. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=306710&Lab=NRMRL&keyword=urease&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=306710&Lab=NRMRL&keyword=urease&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Processes of Ammonia <span class="hlt">Air</span>-Surface <span class="hlt">Exchange</span> in a Fertilized Zea Mays Canopy</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Recent incorporation of coupled soil biogeochemical and bi-directional NH3 <span class="hlt">air</span>-surface <span class="hlt">exchange</span> algorithms into regional <span class="hlt">air</span> quality models holds promise for further reducing uncertainty in estimates of NH3 emissions from fertilized soils. While this advancement represents a sig...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150018068','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150018068"><span>National <span class="hlt">Air</span> Space (NAS) Data <span class="hlt">Exchange</span> Environment Through 2060</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roy, Aloke</p> <p>2015-01-01</p> <p>NASA's NextGen Concepts and Technology Development (CTD) Project focuses on capabilities to improve safety, capacity and efficiency of the National <span class="hlt">Air</span> Space (NAS). In order to achieve those objectives, NASA sought industry-Government partnerships to research and identify solutions for traffic flow management, dynamic airspace configuration, separation assurance, super density operations, airport surface operations and similar forward-looking <span class="hlt">air</span>-traffic modernization (ATM) concepts. Data <span class="hlt">exchanges</span> over NAS being the key enabler for most of these ATM concepts, the Sub-Topic area 3 of the CTD project sought to identify technology candidates that can satisfy <span class="hlt">air-to-air</span> and <span class="hlt">air</span>/ground communications needs of the NAS in the year 2060 timeframe. Honeywell, under a two-year contract with NASA, is working on this communications technology research initiative. This report summarizes Honeywell's research conducted during the second year of the study task.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JBIS...62..122W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JBIS...62..122W"><span>Heat <span class="hlt">Exchanger</span> Design in Combined Cycle Engines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Webber, H.; Feast, S.; Bond, A.</p> <p></p> <p>Combined cycle engines employing both pre-cooled <span class="hlt">air</span>-breathing and rocket modes of operation are the most promising propulsion system for achieving single stage to orbit vehicles. The <span class="hlt">air</span>-breathing phase is purely for augmentation of the mission velocity required in the rocket phase and as such must be <span class="hlt">mass</span> effective, re-using the components of the rocket cycle, whilst achieving adequate specific impulse. This paper explains how the unique demands placed on the <span class="hlt">air</span>-breathing cycle results in the need for sophisticated thermodynamics and the use of a series of different heat <span class="hlt">exchangers</span> to enable precooling and high pressure ratio compression of the <span class="hlt">air</span> for delivery to the rocket combustion chambers. These major heat <span class="hlt">exchanger</span> roles are; extracting heat from incoming <span class="hlt">air</span> in the precooler, topping up cycle flow temperatures to maintain constant turbine operating conditions and extracting rejected heat from the power cycle via regenerator loops for thermal capacity matching. The design solutions of these heat <span class="hlt">exchangers</span> are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998EPJAP...3..295B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998EPJAP...3..295B"><span>Optimization of heat and <span class="hlt">mass</span> transfers in counterflow corrugated-plate liquid-gas <span class="hlt">exchangers</span> used in a greenhouse dehumidifier</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bentounes, N.; Jaffrin, A.</p> <p>1998-09-01</p> <p>Heat and <span class="hlt">mass</span> transfers occuring in a counterflow direct contact liquid-gas <span class="hlt">exchanger</span> determine the performance of a new greenhouse <span class="hlt">air</span> dehumidifier designed at INRA. This prototype uses triethylene glycol (TEG) as the desiccant fluid which extracts water vapor from the <span class="hlt">air</span>. The regeneration of the TEG desiccant fluid is then performed by direct contact with combustion gas from a high efficiency boiler equipped with a condensor. The heat and <span class="hlt">mass</span> transfers between the thin film of diluted TEG and the hot gas were simulated by a model which uses correlation formula from the literature specifically relevant to the present cross-corrugated plates geometry. A simple set of analytical solutions is first derived, which explains why some possible processes can clearly be far from optimal. Then, more exact numerical calculations confirm that some undesirable water recondensations on the upper part of the <span class="hlt">exchanger</span> were limiting the performance of this prototype. More suitable conditions were defined for the process, which lead to a new design of the apparatus. In this second prototype, a gas-gas <span class="hlt">exchanger</span> provides dryer and cooler gas to the basis of the regenerators, while a warmer TEG is fed on the top. A whole range of operating conditions was experimented and measured parameters were compared with numerical simulations of this new configuration: recondensation did not occur any more. As a consequence, this second prototype was able to concentrate the desiccant fluid at the desired rate of 20 kg H_{2O}/hour, under temperature and humidity conditions which correspond to the dehumidification of a 1000 m2 greenhouse heated at night during the winter season.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A43C0283L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A43C0283L"><span><span class="hlt">Air</span>-sea <span class="hlt">Exchange</span> of Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs), Organochlorine Pesticides (OCPs) and Polybrominated Diphenyl Ethers (PBDEs) in the Mediterranean Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lammel, G. P.; Heil, A.; Kukucka, P.; Meixner, F. X.; Mulder, M. D.; Prybilova, P.; Prokes, R.; Rusina, T. S.; Song, G. Z.; Vrana, B.</p> <p>2015-12-01</p> <p>The marine atmospheric environment is a receptor for persistent organic pollutants (POPs) which are advected from sources on land, primary, such as biomass burning by-products (PAHs, dioxins), and secondary, such as volatilization from contaminated soils (PCBs, pesticides). Primary sources do not exist in the marine environment, except for PAHs (ship engines) but following previous atmospheric deposition, the sea surface may turn to a secondary source by reversal of diffusive <span class="hlt">air</span>-sea <span class="hlt">mass</span> <span class="hlt">exchange</span>. No monitoring is in place. We studied the vertical fluxes of a wide range of primary and secondary emitted POPs based on measurements in <span class="hlt">air</span> and surface seawater at a remote coastal site in the eastern Mediterranean (2012). To this end, silicon rubbers were used as passive water samplers, vertical concentration gradients were determined in <span class="hlt">air</span> and fluxes were quantified based on Eddy covariance. Diffusive <span class="hlt">air</span>-sea <span class="hlt">exchange</span> fluxes of hexachlorocyclohexanes (HCHs) and semivolatile PAHs were found close to phase equilibrium, except one PAH, retene, a wood burning tracer, was found seasonally net-volatilisational. Some PCBs, p,p'-DDE, penta- and hexachlorobenzene (PeCB, HCB) were mostly net-depositional, while PBDEs were net-volatilizational. Fluxes determined at a a remote coastal site ranged -33 - +2.4 µg m-2 d-1 for PAHs and -4.0 - +0.3 µg m-2 d-1for halogenated compounds (< 0 means net-deposition, > 0 means net-volatilization). It is concluded that nowadays in open seas more pollutants are undergoing reversal of the direction of <span class="hlt">air</span>-sea <span class="hlt">exchange</span>. Recgional fire activity records in combination with box model simulations suggest that deposition of retene during summer is followed by a reversal of <span class="hlt">air</span>-sea <span class="hlt">exchange</span>. The seawater surface as secondary source of pollution should be assessed based on flux measurements across seasons and over longer time periods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=104827&keyword=applications+AND+thermodynamic&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=104827&keyword=applications+AND+thermodynamic&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>A CRITICAL ASSESSMENT OF ELEMENTAL MERCURY <span class="hlt">AIR</span>/WATER <span class="hlt">EXCHANGE</span> PARTNERS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Although evasion of elemental mercury from aquatic systems can significantly deplete net mercury accumulation resulting from atmospheric deposition, the current ability to model elemental mercury <span class="hlt">air</span>/water <span class="hlt">exchange</span> is limited by uncertainties in our understanding of all gaseous a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15859112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15859112"><span>Measurement of the oxygen <span class="hlt">mass</span> transfer through the <span class="hlt">air</span>-water interface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mölder, Erik; Mashirin, Alelxei; Tenno, Toomas</p> <p>2005-01-01</p> <p>Gas <span class="hlt">mass</span> transfer through the liquid-gas interface has enormous importance in various natural and industrial processes. Surfactants or insoluble compounds adsorbed onto an interface will inhibit the gas <span class="hlt">mass</span> transfer through the liquid-gas surface. This study presents a technique for measuring the oxygen <span class="hlt">mass</span> transfer through the <span class="hlt">air</span>-water interface. Experimental data obtained with the measuring device were incorporated into a novel mathematical model, which allowed one to calculate diffusion conduction of liquid surface layer and oxygen <span class="hlt">mass</span> transfer coefficient in the liquid surface layer. A special measurement cell was constructed. The most important part of the measurement cell is a chamber containing the electrochemical oxygen sensor inside it. Gas <span class="hlt">exchange</span> between the volume of the chamber and the external environment takes place only through the investigated surface layer. Investigated liquid was deoxygenated, which triggers the oxygen <span class="hlt">mass</span> transfer from the chamber through the liquid-<span class="hlt">air</span> interface into the liquid phase. The decrease of oxygen concentration in the cell during time was measured. By using this data it is possible to calculate diffusional parameters of the water surface layer. Diffusion conduction of oxygen through the <span class="hlt">air</span>-water surface layer of selected wastewaters was measured. The diffusion conduction of different wastewaters was about 3 to 6 times less than in the unpolluted water surface. It was observed that the dilution of wastewater does not have a significant impact on the oxygen diffusion conduction through the wastewater surface layer. This fact can be explained with the presence of the compounds with high surface activity in the wastewater. Surfactants achieved a maximum adsorption and, accordingly, the maximum decrease of oxygen permeability already at a very low concentration of surfactants in the solution. Oxygen <span class="hlt">mass</span> transfer coefficient of the surface layer of the water is found to be Ds/ls = 0.13 x 10(-3) x cm/s. A simple</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5907500','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5907500"><span>The Area between <span class="hlt">Exchange</span> Curves as a Measure of Conformational Differences in Hydrogen-Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry Studies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mazur, Sharlyn J.; Weber, Daniel P.</p> <p>2018-01-01</p> <p>Hydrogen-deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) provides information about protein conformational mobility under native conditions. The area between <span class="hlt">exchange</span> curves, Abec, a functional data analysis concept, was adapted to the interpretation of HDX-MS data and provides a useful measure of <span class="hlt">exchange</span> curve dissimilarity for tests of significance. Importantly, for most globular proteins under native conditions, Abec values provide an estimate of the log ratio of <span class="hlt">exchange</span>-competent fractions in the two states, and thus are related to differences in the free energy of microdomain unfolding. PMID:28236290</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28753295','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28753295"><span>Empirical Correction for Differences in Chemical <span class="hlt">Exchange</span> Rates in Hydrogen <span class="hlt">Exchange-Mass</span> Spectrometry Measurements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Toth, Ronald T; Mills, Brittney J; Joshi, Sangeeta B; Esfandiary, Reza; Bishop, Steven M; Middaugh, C Russell; Volkin, David B; Weis, David D</p> <p>2017-09-05</p> <p>A barrier to the use of hydrogen <span class="hlt">exchange-mass</span> spectrometry (HX-MS) in many contexts, especially analytical characterization of various protein therapeutic candidates, is that differences in temperature, pH, ionic strength, buffering agent, or other additives can alter chemical <span class="hlt">exchange</span> rates, making HX data gathered under differing solution conditions difficult to compare. Here, we present data demonstrating that HX chemical <span class="hlt">exchange</span> rates can be substantially altered not only by the well-established variables of temperature and pH but also by additives including arginine, guanidine, methionine, and thiocyanate. To compensate for these additive effects, we have developed an empirical method to correct the hydrogen-<span class="hlt">exchange</span> data for these differences. First, differences in chemical <span class="hlt">exchange</span> rates are measured by use of an unstructured reporter peptide, YPI. An empirical chemical <span class="hlt">exchange</span> correction factor, determined by use of the HX data from the reporter peptide, is then applied to the HX measurements obtained from a protein of interest under different solution conditions. We demonstrate that the correction is experimentally sound through simulation and in a proof-of-concept experiment using unstructured peptides under slow-<span class="hlt">exchange</span> conditions (pD 4.5 at ambient temperature). To illustrate its utility, we applied the correction to HX-MS excipient screening data collected for a pharmaceutically relevant IgG4 mAb being characterized to determine the effects of different formulations on backbone dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1170410','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1170410"><span>Solid oxide fuel cell power plant having a fixed contact oxidation catalyzed section of a multi-section cathode <span class="hlt">air</span> heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Saito, Kazuo; Lin, Yao</p> <p>2015-02-17</p> <p>The multi-section cathode <span class="hlt">air</span> heat <span class="hlt">exchanger</span> (102) includes at least a first heat <span class="hlt">exchanger</span> section (104), and a fixed contact oxidation catalyzed section (126) secured adjacent each other in a stack association. Cool cathode inlet <span class="hlt">air</span> flows through cool <span class="hlt">air</span> channels (110) of the at least first (104) and oxidation catalyzed sections (126). Hot anode exhaust flows through hot <span class="hlt">air</span> channels (124) of the oxidation catalyzed section (126) and is combusted therein. The combusted anode exhaust then flows through hot <span class="hlt">air</span> channels (112) of the first section (104) of the cathode <span class="hlt">air</span> heat <span class="hlt">exchanger</span> (102). The cool and hot <span class="hlt">air</span> channels (110, 112) are secured in direct heat <span class="hlt">exchange</span> relationship with each other so that temperatures of the heat <span class="hlt">exchanger</span> (102) do not exceed 800.degree. C. to minimize requirements for using expensive, high-temperature alloys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12806145','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12806145"><span>Mercury <span class="hlt">exchange</span> at the <span class="hlt">air</span>-water-soil interface: an overview of methods.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fang, Fengman; Wang, Qichao; Liu, Ruhai</p> <p>2002-06-12</p> <p>An attempt is made to assess the present knowledge about the methods of determining mercury (Hg) <span class="hlt">exchange</span> at the <span class="hlt">air</span>-water-soil interface during the past 20 years. Methods determining processes of wet and dry removal/deposition of atmospheric Hg to aquatic and terrestrial ecosystems, as well as methods determining Hg emission fluxes to the atmosphere from natural surfaces (soil and water) are discussed. On the basis of the impressive advances that have been made in the areas relating to Hg <span class="hlt">exchange</span> among <span class="hlt">air</span>-soil-water interfaces, we analyzed existing problems and shortcomings in our current knowledge. In addition, some important fields worth further research are discussed and proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980Tell...32..470H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980Tell...32..470H"><span>Gas <span class="hlt">exchange</span> across the <span class="hlt">air</span>-sea interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hasse, L.; Liss, P. S.</p> <p>1980-10-01</p> <p>The physics of gas <span class="hlt">exchange</span> at the <span class="hlt">air</span>-sea interface are reviewed. In order to describe the transfer of gases in the liquid near the boundary, a molecular plus eddy diffusivity concept is used, which has been found useful for smooth flow over solid surfaces. From consideration of the boundary conditions, a similar dependence of eddy diffusivity on distance from the interface can be derived for the flow beneath a gas/liquid interface, at least in the absence of waves. The influence of waves is then discussed. It is evident from scale considerations that the effect of gravity waves is small. It is known from wind tunnel work that capillary waves enhance gas transfer considerably. The existing hypotheses are apparently not sufficient to explain the observations. Examination of field data is even more frustrating since the data do not show the expected increase of gas <span class="hlt">exchange</span> with wind speed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15330437','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15330437"><span>[Comparison of <span class="hlt">air</span>/soil mercury <span class="hlt">exchange</span> between warm and cold season in Hongfeng Reservoir region].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Shao-feng; Feng, Xin-bin; Qiu, Guang-le; Fu, Xue-wu</p> <p>2004-01-01</p> <p>In July 2002 and March 2003, the mercury <span class="hlt">exchange</span> flux between soil and <span class="hlt">air</span> was measured using dynamic flux chamber method in Hongfeng Reservoir region. Mercury <span class="hlt">exchange</span> flux is (27.4 +/- 40.1) ng x (m2 x h)(-1) (n = 255) and (5.6 +/- 19.4) ng x (m2 x h)(-1) (n = 192) in summer and winter respectively. The correlation coefficient between mercury flux and solar radiation, <span class="hlt">air</span> temperature, soil temperature is 0.74, 0.83 and 0.80 in summer, and 0.88, 0.56 and 0.59 in winter. From the data, it was found that the mercury emission is stronger in summer than that in winter, and compared to winter, mercury <span class="hlt">exchange</span> between soil and <span class="hlt">air</span> depends more on meteorological conditions in summer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12719071','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12719071"><span>Experimental study of viscoelastic in the prevention of corneal endothelial desiccation injury from vitreal fluid-<span class="hlt">air</span> <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cekiç, Osman; Ohji, Masahito; Zheng, Yuping; Hayashi, Atsushi; Kusaka, Shunji; Tano, Yasuo</p> <p>2003-05-01</p> <p>To evaluate the usefulness of viscoelastic in protecting the corneal endothelium from desiccation injury associated with fluid-<span class="hlt">air</span> <span class="hlt">exchange</span> in a rabbit model. Experimental study. Rabbit eyes undergoing pars plana lensectomy and vitrectomy were insufflated with either dry or humidified <span class="hlt">air</span> for 20 minutes following introduction of either Opegan (sodium hyaluronate 1.0%; Santen, Osaka, Japan) or Viscoat (sodium hyaluronate 3%-chondroitin sulfate 4%; Alcon, Tokyo, Japan) into the anterior chamber. In two other groups of rabbit eyes, the same procedure was performed without using any viscoelastic agent. Corneas obtained from rabbits undergoing surgery were compared with corneas obtained from rabbits not undergoing surgery. Potential alterations in the corneal endothelium were investigated by scanning electron microscopy, by Phalloidin-FITC staining of actin and by in vitro measurements of corneal permeability for carboxyfluorescein using a diffusion chamber. Scanning electron microscopy displayed less distortion of corneal endothelium with Opegan and Viscoat compared with the dry <span class="hlt">air</span>-only exposed corneas. Using humidified <span class="hlt">air</span> in Opegan and Viscoat coated corneas maintained the normal actin cytoskeleton during fluid-<span class="hlt">air</span> <span class="hlt">exchange</span>. Paracellular leakage was much less with Opegan and Viscoat use following infusion of dry <span class="hlt">air</span> comparing to that of dry <span class="hlt">air</span>-only group (P =.026 and P =.041). The difference was much more striking following humidified <span class="hlt">air</span> infusion in Opegan or Viscoat coated corneas comparing to dry <span class="hlt">air</span>-only infused corneas (P <.002 and P <.002). Coating of rabbit corneal endothelium with Opegan or Viscoat before fluid-<span class="hlt">air</span> <span class="hlt">exchange</span> largely prevents dry <span class="hlt">air</span> damage to the endothelium. Infusion of humidified <span class="hlt">air</span> further protects corneal endothelium during fluid-<span class="hlt">air</span> <span class="hlt">exchange</span> in aphakic rabbit eyes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19848411','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19848411"><span>Online hydrogen/deuterium <span class="hlt">exchange</span> performed in the ion mobility cell of a hybrid <span class="hlt">mass</span> spectrometer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nagy, Kornél; Redeuil, Karine; Rezzi, Serge</p> <p>2009-11-15</p> <p>The present paper describes the performance of online, gas-phase hydrogen/deuterium <span class="hlt">exchange</span> implemented in the ion mobility cell of a quadrupole time-of-flight <span class="hlt">mass</span> spectrometer. Deuterium oxide and deuterated methanol were utilized to create deuterated vapor that is introduced into the ion mobility region of the <span class="hlt">mass</span> spectrometer. Hydrogen/deuterium <span class="hlt">exchange</span> occurs spontaneously in the milliseconds time frame without the need of switching the instrument into ion mobility mode. The <span class="hlt">exchange</span> was studied in case of low molecular weight molecules and proteins. The observed number of <span class="hlt">exchanged</span> hydrogens was equal to the number of theoretically <span class="hlt">exchangeable</span> hydrogens for all low molecular weight compounds. This method needs only minimal instrumental modifications, is simple, cheap, environment friendly, compatible with ultraperformance liquid chromatography, and can be implemented on commercially available instruments. It does not compromise choice of liquid chromatographic solvents and accurate <span class="hlt">mass</span> or parallel-fragmentation (MS(E)) methods. The performance of this method was compared to that of conventional alternatives where the deuterated solvent is introduced into the cone gas of the instrument. Although the degree of <span class="hlt">exchange</span> was similar between the two methods, the "cone gas method" requires 10 times higher deuterated solvent volumes (50 muL/min) and offers reduced sensitivity in the tandem <span class="hlt">mass</span> spectrometry (MS/MS) mode. The presented method is suggested as a standard future element of <span class="hlt">mass</span> spectrometers to aid online structural characterization of unknowns and to study conformational changes of proteins with hydrogen/deuterium <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1358252','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1358252"><span>Miniaturized <span class="hlt">Air</span>-to-Refrigerant Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Radermacher, Reinhard; Bacellar, Daniel; Aute, Vikrant</p> <p></p> <p><span class="hlt">Air</span>-to-refrigerant Heat <span class="hlt">eXchangers</span> (HX) are an essential component of Heating, Ventilation, <span class="hlt">Air</span>-Conditioning, and Refrigeration (HVAC&R) systems, serving as the main heat transfer component. The major limiting factor to HX performance is the large airside thermal resistance. Recent literature aims at improving heat transfer performance by utilizing enhancement methods such as fins and small tube diameters; this has lead to almost exhaustive research on the microchannel HX (MCHX). The objective of this project is to develop a miniaturized <span class="hlt">air</span>-to-refrigerant HX with at least 20% reduction in volume, material volume, and approach temperature compared to current state-of-the-art multiport flat tube designs andmore » also be capable of production within five years. Moreover, the proposed HX’s are expected to have good water drainage and should succeed in both evaporator and condenser applications. The project leveraged Parallel-Parametrized Computational Fluid Dynamics (PPCFD) and Approximation-Assisted Optimization (AAO) techniques to perform multi-scale analysis and shape optimization with the intent of developing novel HX designs whose thermal-hydraulic performance exceeds that of state-of-the-art MCHX. Nine heat <span class="hlt">exchanger</span> geometries were initially chosen for detailed analysis, selected from 35+ geometries which were identified in previous work at the University of Maryland, College Park. The newly developed optimization framework was exercised for three design optimization problems: (DP I) 1.0kW radiator, (DP II) 10kW radiator and (DP III) 10kW two-phase HX. DP I consisted of the design and optimization of 1.0kW <span class="hlt">air</span>-to-water HX’s which exceeded the project requirements of 20% volume/material reduction and 20% better performance. Two prototypes for the 1.0kW HX were prototyped, tested and validated using newly-designed airside and refrigerant side test facilities. DP II, a scaled version DP I for 10kW <span class="hlt">air</span>-to-water HX applications, also yielded optimized HX</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGeo...10.1379C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGeo...10.1379C"><span>Technical Note: A simple method for <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> measurements in mesocosms and its application in carbon budgeting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Czerny, J.; Schulz, K. G.; Ludwig, A.; Riebesell, U.</p> <p>2013-03-01</p> <p>Mesocosms as large experimental units provide the opportunity to perform elemental <span class="hlt">mass</span> balance calculations, e.g. to derive net biological turnover rates. However, the system is in most cases not closed at the water surface and gases <span class="hlt">exchange</span> with the atmosphere. Previous attempts to budget carbon pools in mesocosms relied on educated guesses concerning the <span class="hlt">exchange</span> of CO2 with the atmosphere. Here, we present a simple method for precise determination of <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> in mesocosms using N2O as a deliberate tracer. Beside the application for carbon budgeting, transfer velocities can be used to calculate <span class="hlt">exchange</span> rates of any gas of known concentration, e.g. to calculate aquatic production rates of climate relevant trace gases. Using an arctic KOSMOS (Kiel Off Shore Mesocosms for future Ocean Simulation) experiment as an exemplary dataset, it is shown that the presented method improves accuracy of carbon budget estimates substantially. Methodology of manipulation, measurement, data processing and conversion to CO2 fluxes are explained. A theoretical discussion of prerequisites for precise gas <span class="hlt">exchange</span> measurements provides a guideline for the applicability of the method under various experimental conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=180684&keyword=global+AND+water+AND+issues&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=180684&keyword=global+AND+water+AND+issues&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>ISSUES IN SIMULATING ELEMENTAL MERCURY <span class="hlt">AIR</span>/WATER <span class="hlt">EXCHANGE</span> AND AQUEOUS MONOMETHYLMERCURY SPECIATION</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This presentation focuses on two areas relevant to assessing the global fate and bioavailability of mercury: elemental mercury <span class="hlt">air</span>/water <span class="hlt">exchange</span> and aqueous environmental monomethylmercury speciation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1332306','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1332306"><span>Membrane device and process for <span class="hlt">mass</span> <span class="hlt">exchange</span>, separation, and filtration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Liu, Wei; Canfield, Nathan L.</p> <p>2016-11-15</p> <p>A membrane device and processes for fabrication and for using are disclosed. The membrane device may include a number of porous metal membranes that provide a high membrane surface area per unit volume. The membrane device provides various operation modes that enhance throughput and selectivity for <span class="hlt">mass</span> <span class="hlt">exchange</span>, <span class="hlt">mass</span> transfer, separation, and/or filtration applications between feed flow streams and permeate flow streams.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DFDL38005L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DFDL38005L"><span>Numerical analysis of heat and <span class="hlt">mass</span> transfer for water recovery in an evaporative cooling tower</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Hyunsub; Son, Gihun</p> <p>2017-11-01</p> <p>Numerical analysis is performed for water recovery in an evaporative cooling tower using a condensing heat <span class="hlt">exchanger</span>, which consists of a humid <span class="hlt">air</span> channel and an ambient dry <span class="hlt">air</span> channel. The humid <span class="hlt">air</span> including water vapor produced in an evaporative cooling tower is cooled by the ambient dry <span class="hlt">air</span> so that the water vapor is condensed and recovered to the liquid water. The conservation equations of <span class="hlt">mass</span>, momentum, energy and vapor concentration in each fluid region and the energy equation in a solid region are simultaneously solved with the heat and <span class="hlt">mass</span> transfer boundary conditions coupled to the effect of condensation on the channel surface of humid <span class="hlt">air</span>. The present computation demonstrates the condensed water film distribution on the humid <span class="hlt">air</span> channel, which is caused by the vapor <span class="hlt">mass</span> transfer between the humid <span class="hlt">air</span> and the colder water film surface, which is coupled to the indirect heat <span class="hlt">exchange</span> with the ambient <span class="hlt">air</span>. Computations are carried out to predict water recovery rate in parallel, counter and cross-flow type heat <span class="hlt">exchangers</span>. The effects of <span class="hlt">air</span> flow rate and channel interval on the water recovery rate are quantified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JPS...243..946K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JPS...243..946K"><span>Numerical investigation of interfacial transport resistance due to water droplets in proton <span class="hlt">exchange</span> membrane fuel cell <span class="hlt">air</span> channels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koz, Mustafa; Kandlikar, Satish G.</p> <p>2013-12-01</p> <p>Oxygen transport resistance at the <span class="hlt">air</span> flow channel and gas diffusion layer (GDL) interface is needed in modelling the performance of a proton <span class="hlt">exchange</span> membrane fuel cell (PEMFC). This resistance is expressed through the non-dimensional Sherwood number (Sh). The effect of the presence of a droplet on Sh is studied numerically in an isolated <span class="hlt">air</span> flow channel using a commercially available package, COMSOL Multiphysics®. A droplet is represented as a solid obstruction placed on the GDL-channel interface and centred along the channel width. The effect of a single droplet is first studied for a range of superficial mean <span class="hlt">air</span> velocities and droplet sizes. Secondly, the effect of droplet spacing on Sh is studied through simulations of two consecutive droplets. Lastly, multiple droplets in a row are studied as a more representative case of a PEMFC <span class="hlt">air</span> flow channel. The results show that the droplets significantly increase Sh above the fully developed value in the wake region. This enhancement increases with the number of droplets, droplet size, and superficial mean <span class="hlt">air</span> velocity. Moreover, the analogy between <span class="hlt">mass</span> and heat transfer is investigated by comparing Sh to the equivalent Nusselt number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830026675','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830026675"><span>Use of cooling <span class="hlt">air</span> heat <span class="hlt">exchangers</span> as replacements for hot section strategic materials</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gauntner, J. W.</p> <p>1983-01-01</p> <p>Because of financial and political constraints, strategic aerospace materials required for the hot section of future engines might be in short supply. As an alternative to these strategic materials, this study examines the use of a cooling <span class="hlt">air</span> heat <span class="hlt">exchanger</span> in combination with less advanced hot section materials. Cycle calculations are presented for future turbofan systems with overall pressure ratios to 65, bypass ratios near 13, and combustor exit temperatures to 3260 R. These calculations quantify the effect on TSFC of using a decreased materials technology in a turbofan system. The calculations show that the cooling <span class="hlt">air</span> heat <span class="hlt">exchanger</span> enables the feasibility of these engines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25743409','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25743409"><span>Estimation of <span class="hlt">air</span>-water gas <span class="hlt">exchange</span> coefficient in a shallow lagoon based on 222Rn <span class="hlt">mass</span> balance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cockenpot, S; Claude, C; Radakovitch, O</p> <p>2015-05-01</p> <p>The radon-222 <span class="hlt">mass</span> balance is now commonly used to quantify water fluxes due to Submarine Groundwater Discharge (SGD) in coastal areas. One of the main loss terms of this <span class="hlt">mass</span> balance, the radon evasion to the atmosphere, is based on empirical equations. This term is generally estimated using one among the many empirical equations describing the gas transfer velocity as a function of wind speed that have been proposed in the literature. These equations were, however, mainly obtained from areas of deep water and may be less appropriate for shallow areas. Here, we calculate the radon <span class="hlt">mass</span> balance for a windy shallow coastal lagoon (mean depth of 6m and surface area of 1.55*10(8) m(2)) and use these data to estimate the radon loss to the atmosphere and the corresponding gas transfer velocity. We present new equations, adapted to our shallow water body, to express the gas transfer velocity as a function of wind speed at 10 m height (wind range from 2 to 12.5 m/s). When compared with those from the literature, these equations fit particularly well with the one of Kremer et al. (2003). Finally, we emphasize that some gas transfer <span class="hlt">exchange</span> may always occur, even for conditions without wind. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20001972-waking-sleeping-giant-introducing-new-heat-exchanger-technology-residential-air-conditioning-marketplace','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20001972-waking-sleeping-giant-introducing-new-heat-exchanger-technology-residential-air-conditioning-marketplace"><span>Waking the sleeping giant: Introducing new heat <span class="hlt">exchanger</span> technology into the residential <span class="hlt">air</span>-conditioning marketplace</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chapp, T.; Voss, M.; Stephens, C.</p> <p>1998-07-01</p> <p>The <span class="hlt">Air</span> Conditioning Industry has made tremendous strides in improvements to the energy efficiency and reliability of its product offerings over the past 40 years. These improvement can be attributed to enhancements of components, optimization of the energy cycle, and modernized and refined manufacturing techniques. During this same period, energy consumption for space cooling has grown significantly. In January of 1992, the minimum efficiency requirement for central <span class="hlt">air</span> conditioning equipment was raised to 10 SEER. This efficiency level is likely to increase further under the auspices of the National Appliance Energy Conservation Act (NAECA). A new type of heat exchangermore » was developed for <span class="hlt">air</span> conditioning equipment by Modine Manufacturing Company in the early 1990's. Despite significant advantages in terms of energy efficiency, dehumidification, durability, and refrigerant charge there has been little interest expressed by the <span class="hlt">air</span> conditioning industry. A cooperative effort between Modine, various utilities, and several state energy offices has been organized to test and demonstrate the viability of this heat <span class="hlt">exchanger</span> design throughout the nation. This paper will review the fundamentals of heat <span class="hlt">exchanger</span> design and document this simple, yet novel technology. These experiences involving equipment retrofits have been documented with respect to the performance potential of <span class="hlt">air</span> conditioning system constructed with PF{trademark} Heat <span class="hlt">Exchangers</span> (generically referred to as microchannel heat <span class="hlt">exchangers</span>) from both an energy efficiency as well as a comfort perspective. The paper will also detail the current plan to introduce 16 to 24 systems into an extended field test throughout the US which commenced in the Fall of 1997.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=volume+AND+concept&pg=7&id=EJ667010','ERIC'); return false;" href="https://eric.ed.gov/?q=volume+AND+concept&pg=7&id=EJ667010"><span>Authentic Assessment in the Geometry Classroom: Calculating the Classroom <span class="hlt">Air-Exchange</span> Rate.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Erich, David J.</p> <p>2002-01-01</p> <p>Introduces a room <span class="hlt">air-exchange</span> activity designed to assess student understanding of the concept of volume. Lists materials for the activity and its procedures. Includes the lesson plan and a student worksheet. (KHR)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B34A..02L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B34A..02L"><span><span class="hlt">Air</span>-Water <span class="hlt">Exchange</span> of Legacy and Emerging Organic Pollutants across the Great Lakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lohmann, R.; Ruge, Z.; Khairy, M.; Muir, D.; Helm, P.</p> <p>2014-12-01</p> <p>Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are transported to great water bodies via long-range atmospheric transport and released from the surface water as <span class="hlt">air</span> concentrations continue to diminish. As the largest fresh water bodies in North America, the Great Lakes have both the potential to accumulate and serve as a secondary source of persistent bioaccumulative toxins. OCP and PCB concentrations were sampled at 30+ sites across Lake Superior, Ontario and Erie in the summer of 2011. Polyethylene passive samplers (PEs) were simultaneously deployed in surface water and near surface atmosphere to determine <span class="hlt">air</span>-water gaseous <span class="hlt">exchange</span> of OCPs and PCBs. In Lake Superior, surface water and atmospheric concentrations were dominated by α-HCH (average 250 pg/L and 4.2 pg/m3, respectively), followed by HCB (average 17 pg/L and 89 pg/m3, respectively). <span class="hlt">Air</span>-water <span class="hlt">exchange</span> varied greatly between sites and individual OCPs, however α-endosulfan was consistently deposited into the surface water (average 19 pg/m2/day). PCBs in the <span class="hlt">air</span> and water were characterized by penta- and hexachlorobiphenyls with distribution along the coast correlated with proximity to developed areas. <span class="hlt">Air</span>-water <span class="hlt">exchange</span> gradients generally yielded net volatilization of PCBs out of Lake Superior. Gaseous concentrations of hexachlorobenzene, dieldrin and chlordanes were significantly higher (p < 0.05) at Lake Erie than Lake Ontario. A multiple linear regression that incorporated meteorological, landuse and population data was used to explain variability in the atmospheric concentrations. Results indicated that landuse (urban and/or cropland) greatly explained the variability in the data. Freely dissolved concentrations of OCPs (<LOD-114 pg/L) were lower than previously detected concentrations. Nonetheless, concentrations of p,p'-DDE and chlordanes were higher than water quality guidelines for the protection of human health from the consumption of fish. Spatial distributions of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21917934','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21917934"><span><span class="hlt">Air</span>-gas <span class="hlt">exchange</span> reevaluated: clinically important results of a computer simulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shunmugam, Manoharan; Shunmugam, Sudhakaran; Williamson, Tom H; Laidlaw, D Alistair</p> <p>2011-10-21</p> <p>The primary aim of this study was to evaluate the efficiency of <span class="hlt">air</span>-gas <span class="hlt">exchange</span> techniques and the factors that influence the final concentration of an intraocular gas tamponade. Parameters were varied to find the optimum method of performing an <span class="hlt">air</span>-gas <span class="hlt">exchange</span> in ideal circumstances. A computer model of the eye was designed using 3D software with fluid flow analysis capabilities. Factors such as angular distance between ports, gas infusion gauge, exhaust vent gauge and depth were varied in the model. Flow rate and axial length were also modulated to simulate faster injections and more myopic eyes, respectively. The flush volume of gas required to achieve a 97% intraocular gas fraction concentration were compared. Modulating individual factors did not reveal any clinically significant difference in the angular distance between ports, exhaust vent size, and depth or rate of gas injection. In combination, however, there was a 28% increase in <span class="hlt">air</span>-gas <span class="hlt">exchange</span> efficiency comparing the most efficient with the least efficient studied parameters in this model. The gas flush volume required to achieve a 97% gas fill also increased proportionately at a ratio of 5.5 to 6.2 times the volume of the eye. A 35-mL flush is adequate for eyes up to 25 mm in axial length; however, eyes longer than this would require a much greater flush volume, and surgeons should consider using two separate 50-mL gas syringes to ensure optimal gas concentration for eyes greater than 25 mm in axial length.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27617333','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27617333"><span>Persistent organochlorine pesticides and polychlorinated biphenyls in <span class="hlt">air</span> of the North Sea region and <span class="hlt">air</span>-sea <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mai, Carolin; Theobald, Norbert; Hühnerfuss, Heinrich; Lammel, Gerhard</p> <p>2016-12-01</p> <p>Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were studied to determine occurrence, levels and spatial distribution in the marine atmosphere and surface seawater during cruises in the German Bight and the wider North Sea in spring and summer 2009-2010. In general, the concentrations found in <span class="hlt">air</span> are similar to, or below, the levels at coastal or near-coastal sites in Europe. Hexachlorobenzene and α-hexachlorocyclohexane (α-HCH) were close to phase equilibrium, whereas net atmospheric deposition was observed for γ-HCH. The results suggest that declining trends of HCH in seawater have been continuing for γ-HCH but have somewhat levelled off for α-HCH. Dieldrin displayed a close to phase equilibrium in nearly all the sampling sites, except in the central southwestern part of the North Sea. Here atmospheric deposition dominates the <span class="hlt">air</span>-sea <span class="hlt">exchange</span>. This region, close to the English coast, showed remarkably increased surface seawater concentrations. This observation depended neither on riverine input nor on the elevated abundances of dieldrin in the <span class="hlt">air</span> <span class="hlt">masses</span> of central England. A net depositional flux of p,p'-DDE into the North Sea was indicated by both its abundance in the marine atmosphere and the changes in metabolite pattern observed in the surface water from the coast towards the open sea. The long-term trends show that the atmospheric concentrations of DDT and its metabolites are not declining. Riverine input is a major source of PCBs in the German Bight and the wider North Sea. Atmospheric deposition of the lower molecular weight PCBs (PCB28 and PCB52) was indicated as a major source for surface seawater pollution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840032418&hterms=financial+ratios&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dfinancial%2Bratios','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840032418&hterms=financial+ratios&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dfinancial%2Bratios"><span>Use of cooling <span class="hlt">air</span> heat <span class="hlt">exchangers</span> as replacements for hot section strategic materials</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gauntner, J. W.</p> <p>1983-01-01</p> <p>Because of financial and political constraints, strategic aerospace materials required for the hot section of future engines might be in short supply. As an alternative to these strategic materials, this study examines the use of a cooling <span class="hlt">air</span> heat <span class="hlt">exchanger</span> in combination with less advanced hot section materials. Cycle calculations are presented for future turbofan systems with overall pressure ratios to 65, bypass ratios near 13, and combustor exit temperatures to 3260 R. These calculations quantify the effect on TSFC of using a decreased materials technology in a turbofan system. The calculations show that the cooling <span class="hlt">air</span> heat <span class="hlt">exchanger</span> enables the feasibility of these engines. Previously announced in STAR as N83-34946</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=335530&keyword=air&subject=air%20research&showcriteria=2&fed_org_id=111&datebeginpublishedpresented=02/22/2012&dateendpublishedpresented=02/22/2017&sortby=pubdateyear','PESTICIDES'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=335530&keyword=air&subject=air%20research&showcriteria=2&fed_org_id=111&datebeginpublishedpresented=02/22/2012&dateendpublishedpresented=02/22/2017&sortby=pubdateyear"><span>Probabilistic estimation of residential <span class="hlt">air</span> <span class="hlt">exchange</span> rates for ...</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Residential <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AERs) are a key determinant in the infiltration of ambient <span class="hlt">air</span> pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to <span class="hlt">air</span> pollutants have relied on input distributions from AER measurements. An algorithm for probabilistically estimating AER was developed based on the Lawrence Berkley National Laboratory Infiltration model utilizing housing characteristics and meteorological data with adjustment for window opening behavior. The algorithm was evaluated by comparing modeled and measured AERs in four US cities (Los Angeles, CA; Detroit, MI; Elizabeth, NJ; and Houston, TX) inputting study-specific data. The impact on the modeled AER of using publically available housing data representative of the region for each city was also assessed. Finally, modeled AER based on region-specific inputs was compared with those estimated using literature-based distributions. While modeled AERs were similar in magnitude to the measured AER they were consistently lower for all cities except Houston. AERs estimated using region-specific inputs were lower than those using study-specific inputs due to differences in window opening probabilities. The algorithm produced more spatially and temporally variable AERs compared with literature-based distributions reflecting within- and between-city differences, helping reduce error in estimates of <span class="hlt">air</span> pollutant exposure. Published in the Journal of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26196214','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26196214"><span>20 Years of <span class="hlt">Air</span>-Water Gas <span class="hlt">Exchange</span> Observations for Pesticides in the Western Arctic Ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jantunen, Liisa M; Wong, Fiona; Gawor, Anya; Kylin, Henrik; Helm, Paul A; Stern, Gary A; Strachan, William M J; Burniston, Deborah A; Bidleman, Terry F</p> <p>2015-12-01</p> <p>The Arctic has been contaminated by legacy organochlorine pesticides (OCPs) and currently used pesticides (CUPs) through atmospheric transport and oceanic currents. Here we report the time trends and <span class="hlt">air</span>-water <span class="hlt">exchange</span> of OCPs and CUPs from research expeditions conducted between 1993 and 2013. Compounds determined in both <span class="hlt">air</span> and water were trans- and cis-chlordanes (TC, CC), trans- and cis-nonachlors (TN, CN), heptachlor exo-epoxide (HEPX), dieldrin (DIEL), chlorobornanes (ΣCHBs and toxaphene), dacthal (DAC), endosulfans and metabolite endosulfan sulfate (ENDO-I, ENDO-II, and ENDO SUL), chlorothalonil (CHT), chlorpyrifos (CPF), and trifluralin (TFN). Pentachloronitrobenzene (PCNB and quintozene) and its soil metabolite pentachlorothianisole (PCTA) were also found in <span class="hlt">air</span>. Concentrations of most OCPs declined in surface water, whereas some CUPs increased (ENDO-I, CHT, and TFN) or showed no significant change (CPF and DAC), and most compounds declined in <span class="hlt">air</span>. Chlordane compound fractions TC/(TC + CC) and TC/(TC + CC + TN) decreased in water and <span class="hlt">air</span>, while CC/(TC + CC + TN) increased. TN/(TC + CC + TN) also increased in <span class="hlt">air</span> and slightly, but not significantly, in water. These changes suggest selective removal of more labile TC and/or a shift in chlordane sources. Water-<span class="hlt">air</span> fugacity ratios indicated net volatilization (FR > 1.0) or near equilibrium (FR not significantly different from 1.0) for most OCPs but net deposition (FR < 1.0) for ΣCHBs. Net deposition was shown for ENDO-I on all expeditions, while the net <span class="hlt">exchange</span> direction of other CUPs varied. Understanding the processes and current state of <span class="hlt">air</span>-surface <span class="hlt">exchange</span> helps to interpret environmental exposure and evaluate the effectiveness of international protocols and provides insights for the environmental fate of new and emerging chemicals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A53F2321H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A53F2321H"><span>Indoor Levels of Formaldehyde and Other Pollutants and Relationship to <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rates and Human Activities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huangfu, Y.; O'Keeffe, P.; Kirk, M.; Walden, V. P.; Lamb, B. K.; Jobson, B. T.</p> <p>2017-12-01</p> <p>This paper reports results on an indoor <span class="hlt">air</span> quality study conducted on six homes in summer and winter, contrasting indoor and outdoor concentrations of O3, CO, CO2, NOx, PM2.5, and selected volatile organic hydrocarbons measured by PTR-MS. Data were collected as 1 minute averages. <span class="hlt">Air</span> <span class="hlt">exchange</span> rates of the homes were determined by CO2 tracer release. Smart home sensors, recording human activity level in various places in the home, and window and doors openings, were utilized to better understand the link between human activity and indoor <span class="hlt">air</span> pollution. From our study, averaged <span class="hlt">air</span> <span class="hlt">exchange</span> rates of the homes ranged from 0.2 to 1.2 hour-1 and were greatly affected by the ventilation system type and window and door openings. In general, a negative correlation between <span class="hlt">air</span> <span class="hlt">exchange</span> rate and indoor VOCs levels was observed, with large variation of pollutant levels between the homes. For most of the VOCs measured in the house, including formaldehyde and acetaldehyde, summer levels were much higher than winter levels. In some homes formaldehyde levels displayed a time of day variation that was linked to changes in indoor temperature. During a wildfire period in the summer of 2015, outdoor levels of PM2.5, formaldehyde, and benzene dramatically increased, significantly impacting indoor levels due to infiltration. Human activities, such as cooking, can significantly change the levels of most of the compounds measured in the house and the levels can be significantly elevated for short periods of time, with peak levels can be several orders higher compared with typical levels. The data suggest that an outcome of state energy codes that require new homes to be energy efficient, and as a consequence built with lower <span class="hlt">air</span> <span class="hlt">exchange</span> rates, will be unacceptable levels of <span class="hlt">air</span> toxics, notably formaldehyde.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1850k0012Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1850k0012Q"><span>Thermal modelling and control of 130kw direct contact (salt/<span class="hlt">air</span>) heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qureshi, Omer A.; Calvet, Nicolas; Armstrong, Peter R.</p> <p>2017-06-01</p> <p>This work investigates the transient response of a certain type of direct contact heat <span class="hlt">exchanger</span> (DCHX) that consists of packing (Raschig Rings) to increase the surface area for effective heat transfer between molten salt and <span class="hlt">air</span>. Molten salt from the hot tank enters the heat <span class="hlt">exchanger</span> (HX) and exit after heating the <span class="hlt">air</span> still in the molten form. Thermal capacitance of the HX, mainly due to packing and resident salt inside the HX, results in strong transient response. Pure delay from salt residence time may also impact transient response. Both phenomena have been modelled in this paper. A Proportional-Integral controller (PI control) performance has been evaluated to maintain the minimum salt temperature above avoid crystallization temperature of the salt.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870014174','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870014174"><span>Development of an <span class="hlt">air</span> ground data <span class="hlt">exchange</span> concept: Flight deck perspective</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Flathers, G. W., II</p> <p>1987-01-01</p> <p>The planned modernization of the U.S. National Airspace System (NAS) includes the development and use of a digital data link as a means to <span class="hlt">exchange</span> information between aircraft and ground-based facilities. This report presents an operationally-oriented concept on how data link could be used for applications related directly to <span class="hlt">air</span> traffic control. The specific goal is to establish the role that data link could play in the <span class="hlt">air</span>-ground communications. Due regard is given to the unique characteristics of data link and voice communications, current principles of <span class="hlt">air</span> traffic control, operational procedures, human factors/man-machine interfaces, and the integration of data link with other <span class="hlt">air</span> and ground systems. The resulting concept is illustrated in the form of a paper-and-pencil simulation in which data link and voice communications during the course of a hypothetical flight are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59576&keyword=film+AND+analysis&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59576&keyword=film+AND+analysis&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>THE ROLE OF AQUEOUS THIN FILM EVAPORATIVE COOLING ON RATES OF ELEMENTAL MERCURY <span class="hlt">AIR</span>-WATER <span class="hlt">EXCHANGE</span> UNDER TEMPERATURE DISEQUILIBRIUM CONDITIONS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The technical conununity has only recently addressed the role of atmospheric temperature variations on rates of <span class="hlt">air</span>-water vapor phase toxicant <span class="hlt">exchange</span>. The technical literature has documented that: 1) day time rates of elemental mercury vapor phase <span class="hlt">air</span>-water <span class="hlt">exchange</span> can exceed ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28447675','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28447675"><span>Back-<span class="hlt">exchange</span>: a novel approach to quantifying oxygen diffusion and surface <span class="hlt">exchange</span> in ambient atmospheres.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cooper, Samuel J; Niania, Mathew; Hoffmann, Franca; Kilner, John A</p> <p>2017-05-17</p> <p>A novel two-step Isotopic <span class="hlt">Exchange</span> (IE) technique has been developed to investigate the influence of oxygen containing components of ambient <span class="hlt">air</span> (such as H 2 O and CO 2 ) on the effective surface <span class="hlt">exchange</span> coefficient (k*) of a common mixed ionic electronic conductor material. The two step 'back-<span class="hlt">exchange</span>' technique was used to introduce a tracer diffusion profile, which was subsequently measured using Time-of-Flight Secondary Ion <span class="hlt">Mass</span> Spectrometry (ToF-SIMS). The isotopic fraction of oxygen in a dense sample as a function of distance from the surface, before and after the second <span class="hlt">exchange</span> step, could then be used to determine the surface <span class="hlt">exchange</span> coefficient in each atmosphere. A new analytical solution was found to the diffusion equation in a semi-infinite domain with a variable surface <span class="hlt">exchange</span> boundary, for the special case where D* and k* are constant for all <span class="hlt">exchange</span> steps. This solution validated the results of a numerical, Crank-Nicolson type finite-difference simulation, which was used to extract the parameters from the experimental data. When modelling electrodes, D* and k* are important input parameters, which significantly impact performance. In this study La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF6428) was investigated and it was found that the rate of <span class="hlt">exchange</span> was increased by around 250% in ambient <span class="hlt">air</span> compared to high purity oxygen at the same pO 2 . The three experiments performed in this study were used to validate the back-<span class="hlt">exchange</span> approach and show its utility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22268690','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22268690"><span>Sorption-induced effects of humic substances on <span class="hlt">mass</span> transfer of organic pollutants through aqueous diffusion boundary layers: the example of water/<span class="hlt">air</span> <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ramus, Ksenia; Kopinke, Frank-Dieter; Georgi, Anett</p> <p>2012-02-21</p> <p>This study examines the effect of dissolved humic substances (DHS) on the rate of water-gas <span class="hlt">exchange</span> of organic compounds under conditions where diffusion through the aqueous boundary layer is rate-determining. A synthetic surfactant was applied for comparison. <span class="hlt">Mass</span>-transfer coefficients were determined from the rate of depletion of the model compounds by means of an apparatus containing a stirred aqueous solution with continuous purging of the headspace above the solution. In addition, experiments with continuous passive dosing of analytes into the water phase were conducted to simulate a system where thermodynamic activity of the chemical in the aqueous phase is identical in the presence and absence of DHS. The experimental results show that DHS and surfactants can affect water-gas <span class="hlt">exchange</span> rates by the superposition of two mechanisms: (1) hydrodynamic effects due to surface film formation ("surface smoothing"), and (2) sorption-induced effects. Whether sorption accelerates or retards <span class="hlt">mass</span> transfer depends on its effect on the thermodynamic activity of the pollutant in the aqueous phase. <span class="hlt">Mass</span> transfer will be retarded if the activity (or freely dissolved concentration) of the pollutant is decreased due to sorption. If it remains unchanged (e.g., due to fast equilibration with a sediment acting as a large source phase), then DHS and surfactant micelles can act as an additional shuttle for the pollutants, enhancing the flux through the boundary layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AtmEn.178...31J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AtmEn.178...31J"><span>Seasonal atmospheric deposition and <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implications for source-sink processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Yuqing; Lin, Tian; Wu, Zilan; Li, Yuanyuan; Li, Zhongxia; Guo, Zhigang; Yao, Xiaohong</p> <p>2018-04-01</p> <p>In this work, <span class="hlt">air</span> samples and surface seawater samples covering four seasons from March 2014 to January 2015 were collected from a background receptor site in the YRE to explore the seasonal fluxes of <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> and dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the <span class="hlt">air</span>-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. Gaseous PAH release from seawater to the atmosphere averaged 3114 ± 1999 ng m-2 d-1 in a year round. The <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> of PAHs was the dominant process at the <span class="hlt">air</span>-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of total dry and wet deposition. The gas PAH <span class="hlt">exchange</span> flux was dominated by three-ring PAHs, with the highest value in summer and lowest in winter, indicating a marked seasonal variation owing to differences in Henry's law constants associated with temperature, as well as wind speed and gaseous-dissolved gradient among seasons. Based on the simplified <span class="hlt">mass</span> balance estimation, a net 11 tons y-1 of PAHs (mainly three-ring PAHs) were volatilized from seawater to the atmosphere in a ∼20,000 km2 area in the YRE. Other than the year-round Yangtze River input and ocean ship emissions, the selective release of low-molecular-weight PAHs from bottom sediments in winter due to resuspension triggered by the East Asian winter monsoon is another potential source of PAHs. This work suggests that the source-sink processes of PAHs at the <span class="hlt">air</span>-sea interface in the YRE play a crucial role in regional cycling of PAHs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=335106','PESTICIDES'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=335106"><span>Investigation of ammonia <span class="hlt">air</span>-surface <span class="hlt">exchange</span> processes in a ...</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Recent assessments of atmospheric deposition in North America note the increasing importance of reduced (NHx = NH3 + NH4+) forms of nitrogen (N) relative to oxidized forms. This shift in in the composition of inorganic nitrogen deposition has both ecological and policy implications. Deposition budgets developed from inferential models applied at the landscape scale, as well as regional and global chemical transport models, indicate that NH3 dry deposition contributes a significant portion of inorganic N deposition in many areas. However, the bidirectional NH3 flux algorithms employed in these models have not been extensively evaluated for North American conditions (e.g, atmospheric chemistry, meteorology, biogeochemistry). Further understanding of the processes controlling NH3 <span class="hlt">air</span>-surface <span class="hlt">exchange</span> in natural systems is critically needed. Based on preliminary results from the Southern Appalachian Nitrogen Deposition Study (SANDS), this presentation examines processes of NH3 <span class="hlt">air</span>-surface <span class="hlt">exchange</span> in a deciduous montane forest at the Coweeta Hydrologic Laboratory in western North Carolina. A combination of measurements and modeling are used to investigate net fluxes of NH3 above the forest and sources and sinks of NH3 within the canopy and forest floor. Measurements of biogeochemical NH4+ pools are used to characterize emission potential and NH3 compensation points of canopy foliage (i.e., green vegetation), leaf litter, and soil and their relation to NH3 fluxes</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8504G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8504G"><span>Subtropical <span class="hlt">air</span> <span class="hlt">masses</span> over eastern Canada: Their links to extreme precipitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gyakum, John; Wood, Alice; Milrad, Shawn; Atallah, Eyad</p> <p>2017-04-01</p> <p>We investigate extremely warm, moist <span class="hlt">air</span> <span class="hlt">masses</span> with an analysis of 850-hPa equivalent potential temperature (θe) extremes at Montreal, Quebec. The utility of using this metric is that it represents the thermodynamic property of <span class="hlt">air</span> that ascends during a precipitation event. We produce an analysis of the 40 most extreme cases of positive θe, 10 for each season, based upon standardized anomalies from the 33-year climatology. The analysis shows the cases to be characterized by <span class="hlt">air</span> <span class="hlt">masses</span> with distinct subtropical traits for all seasons: reduced static stability, anomalously high precipitable water, and anomalously elevated dynamic tropopause heights. Persistent, slow moving upper- and lower-level features were essential in the build up of high- θe <span class="hlt">air</span> encompassing much of eastern Canada. The trajectory analysis also showed anticyclonic curvature to all paths in all seasons, implying that the subtropical anticyclone is crucial in the transport of high- θe <span class="hlt">air</span>. These atmospheric rivers during the winter are characterized by trajectories from the subtropical North Atlantic, and over the Gulf Stream current, northward into Montreal. In contrast, the summer anticyclonic trajectories are primarily continental, traveling from Texas north-northeastward into the Great Lakes, and then eastward into Montreal. The role of the <span class="hlt">air</span> <span class="hlt">mass</span> in modulating the strength of a precipitation event is addressed with an analysis of the expression, P = RD, where P is the total precipitation, and R is the precipitation rate, averaged through the duration, D, of the event. Though appearing simple, this expression includes R, (assumed to be same as condensation, with an efficiency of 1), which may be expressed as the product of vertical motion and the change of saturation mixing ratio following a moist adiabat, through the troposphere. This expression for R includes the essential ingredients of lift, <span class="hlt">air</span> <span class="hlt">mass</span> temperature, and static stability (implicit in vertical motion). We use this</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=heat+AND+exchange&pg=3&id=EJ582662','ERIC'); return false;" href="https://eric.ed.gov/?q=heat+AND+exchange&pg=3&id=EJ582662"><span>Balloons and Bottles: Activities on <span class="hlt">Air</span>-Sea Heat <span class="hlt">Exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Murphree, Tom</p> <p>1998-01-01</p> <p>Presents an activity designed to demonstrate how heating and cooling an <span class="hlt">air</span> <span class="hlt">mass</span> affects its temperature, volume, density, and pressure. Illustrates how thermal energy can cause atmospheric motion such as expansion, contraction, and winds. (Author/WRM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2954549','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2954549"><span>Modified Perfluorocarbon Tracer Method for Measuring Effective Multizone <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rates</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shinohara, Naohide; Kataoka, Toshiyuki; Takamine, Koichi; Butsugan, Michio; Nishijima, Hirokazu; Gamo, Masashi</p> <p>2010-01-01</p> <p>A modified procedure was developed for the measurement of the effective <span class="hlt">air</span> <span class="hlt">exchange</span> rate, which represents the relationship between the pollutants emitted from indoor sources and the residents’ level of exposure, by placing the dosers of tracer gas at locations that resemble indoor emission sources. To measure the 24-h-average effective <span class="hlt">air</span> <span class="hlt">exchange</span> rates in future surveys based on this procedure, a low-cost, easy-to-use perfluorocarbon tracer (PFT) doser with a stable dosing rate was developed by using double glass vials, a needle, a polyethylene-sintered filter, and a diffusion tube. Carbon molecular sieve cartridges and carbon disulfide (CS2) were used for passive sampling and extraction of the tracer gas, respectively. Recovery efficiencies, sampling rates, and lower detection limits for 24-h sampling of hexafluorobenzene, octafluorotoluene, and perfluoroallylbenzene were 40% ± 3%, 72% ± 5%, and 84% ± 6%; 10.5 ± 1.1, 14.4 ± 1.4, and 12.2 ± 0.49 mL min−1; and 0.20, 0.17, and 0.26 μg m−3, respectively. PMID:20948928</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20948928','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20948928"><span>Modified perfluorocarbon tracer method for measuring effective multizone <span class="hlt">air</span> <span class="hlt">exchange</span> rates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shinohara, Naohide; Kataoka, Toshiyuki; Takamine, Koichi; Butsugan, Michio; Nishijima, Hirokazu; Gamo, Masashi</p> <p>2010-09-01</p> <p>A modified procedure was developed for the measurement of the effective <span class="hlt">air</span> <span class="hlt">exchange</span> rate, which represents the relationship between the pollutants emitted from indoor sources and the residents' level of exposure, by placing the dosers of tracer gas at locations that resemble indoor emission sources. To measure the 24-h-average effective <span class="hlt">air</span> <span class="hlt">exchange</span> rates in future surveys based on this procedure, a low-cost, easy-to-use perfluorocarbon tracer (PFT) doser with a stable dosing rate was developed by using double glass vials, a needle, a polyethylene-sintered filter, and a diffusion tube. Carbon molecular sieve cartridges and carbon disulfide (CS₂) were used for passive sampling and extraction of the tracer gas, respectively. Recovery efficiencies, sampling rates, and lower detection limits for 24-h sampling of hexafluorobenzene, octafluorotoluene, and perfluoroallylbenzene were 40% ± 3%, 72% ± 5%, and 84% ± 6%; 10.5 ± 1.1, 14.4 ± 1.4, and 12.2 ± 0.49 mL min⁻¹; and 0.20, 0.17, and 0.26 μg m⁻³, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27602546','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27602546"><span>Computational methods and challenges in hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Claesen, Jürgen; Burzykowski, Tomasz</p> <p>2017-09-01</p> <p>Hydrogen/Deuterium <span class="hlt">exchange</span> (HDX) has been applied, since the 1930s, as an analytical tool to study the structure and dynamics of (small) biomolecules. The popularity of using HDX to study proteins increased drastically in the last two decades due to the successful combination with <span class="hlt">mass</span> spectrometry (MS). Together with this growth in popularity, several technological advances have been made, such as improved quenching and fragmentation. As a consequence of these experimental improvements and the increased use of protein-HDXMS, large amounts of complex data are generated, which require appropriate analysis. Computational analysis of HDXMS requires several steps. A typical workflow for proteins consists of identification of (non-)deuterated peptides or fragments of the protein under study (local analysis), or identification of the deuterated protein as a whole (global analysis); determination of the deuteration level; estimation of the protection extent or <span class="hlt">exchange</span> rates of the labile backbone amide hydrogen atoms; and a statistically sound interpretation of the estimated protection extent or <span class="hlt">exchange</span> rates. Several algorithms, specifically designed for HDX analysis, have been proposed. They range from procedures that focus on one specific step in the analysis of HDX data to complete HDX workflow analysis tools. In this review, we provide an overview of the computational methods and discuss outstanding challenges. © 2016 Wiley Periodicals, Inc. <span class="hlt">Mass</span> Spec Rev 36:649-667, 2017. © 2016 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28526196','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28526196"><span>Use of a numerical simulation approach to improve the estimation of <span class="hlt">air</span>-water <span class="hlt">exchange</span> fluxes of polycyclic aromatic hydrocarbons in a coastal zone.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lai, I-Chien; Lee, Chon-Lin; Ko, Fung-Chi; Lin, Ju-Chieh; Huang, Hu-Ching; Shiu, Ruei-Feng</p> <p>2017-07-15</p> <p>The <span class="hlt">air</span>-water <span class="hlt">exchange</span> is important for determining the transport, fate, and chemical loading of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere and in aquatic systems. Investigations of PAH <span class="hlt">air</span>-water <span class="hlt">exchange</span> are mostly based on observational data obtained using complicated field sampling processes. This study proposes a new approach to improve the estimation of long-term PAH <span class="hlt">air</span>-water <span class="hlt">exchange</span> fluxes by using a multivariate regression model to simulate hourly gaseous PAH concentrations. Model performance analysis and the benefits from this approach indicate its effectiveness at improving the flux estimations and at decreasing the field sampling difficulty. The proposed GIS mapping approach is useful for box model establishment and is tested for visualization of the spatiotemporal variations of <span class="hlt">air</span>-water <span class="hlt">exchange</span> fluxes in a coastal zone. The <span class="hlt">air</span>-water <span class="hlt">exchange</span> fluxes illustrated by contour maps suggest that the atmospheric PAHs might have greater impacts on offshore sites than on the coastal area in this study. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12578005','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12578005"><span>Effects of <span class="hlt">air</span> current speed on gas <span class="hlt">exchange</span> in plant leaves and plant canopies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kitaya, Y; Tsuruyama, J; Shibuya, T; Yoshida, M; Kiyota, M</p> <p>2003-01-01</p> <p>To obtain basic data on adequate <span class="hlt">air</span> circulation to enhance plant growth in a closed plant culture system in a controlled ecological life support system (CELSS), an investigation was made of the effects of the <span class="hlt">air</span> current speed ranging from 0.01 to 1.0 m s-1 on photosynthesis and transpiration in sweetpotato leaves and photosynthesis in tomato seedlings canopies. The gas <span class="hlt">exchange</span> rates in leaves and canopies were determined by using a chamber method with an infrared gas analyzer. The net photosynthetic rate and the transpiration rate increased significantly as the <span class="hlt">air</span> current speeds increased from 0.01 to 0.2 m s-1. The transpiration rate increased gradually at <span class="hlt">air</span> current speeds ranging from 0.2 to 1.0 m s-1 while the net photosynthetic rate was almost constant at <span class="hlt">air</span> current speeds ranging from 0.5 to 1.0 m s-1. The increase in the net photosynthetic and transpiration rates were strongly dependent on decreased boundary-layer resistances against gas diffusion. The net photosynthetic rate of the plant canopy was doubled by an increased <span class="hlt">air</span> current speed from 0.1 to 1.0 m s-1 above the plant canopy. The results demonstrate the importance of <span class="hlt">air</span> movement around plants for enhancing the gas <span class="hlt">exchange</span> in the leaf, especially in plant canopies in the CELSS. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/newsreleases/settlement-amherst-mass-company-reduces-emissions-air','PESTICIDES'); return false;" href="https://www.epa.gov/newsreleases/settlement-amherst-mass-company-reduces-emissions-air"><span>Settlement with Amherst, <span class="hlt">Mass</span>., Company Reduces Emissions to <span class="hlt">Air</span></span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Under the terms of a recent settlement with the U.S. Environmental Protection Agency (EPA), John S. Lane and Son, Inc. (JS Lane), a sand and gravel company in Amherst, <span class="hlt">Mass</span>., has taken steps to reduce <span class="hlt">air</span> pollution, as required by the Clean <span class="hlt">Air</span> Act (CAA).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmEn.112..106Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmEn.112..106Y"><span>Indoor transient SOA formation from ozone + α-pinene reactions: Impacts of <span class="hlt">air</span> <span class="hlt">exchange</span> and initial product concentrations, and comparison to limonene ozonolysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Youssefi, Somayeh; Waring, Michael S.</p> <p>2015-07-01</p> <p>The ozonolysis of reactive organic gases (ROG), e.g. terpenes, generates secondary organic aerosol (SOA) indoors. The SOA formation strength of such reactions is parameterized by the aerosol <span class="hlt">mass</span> fraction (AMF), a.k.a. SOA yield, which is the <span class="hlt">mass</span> ratio of generated SOA to oxidized ROG. AMFs vary in magnitude both among and for individual ROGs. Here, we quantified dynamic SOA formation from the ozonolysis of α-pinene with 'transient AMFs,' which describe SOA formation due to pulse emission of a ROG in an indoor space with <span class="hlt">air</span> <span class="hlt">exchange</span>, as is common when consumer products are intermittently used in ventilated buildings. We performed 19 experiments at low, moderate, and high (0.30, 0.52, and 0.94 h-1, respectively) <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AER) at varying concentrations of initial reactants. Transient AMFs as a function of peak SOA concentrations ranged from 0.071 to 0.25, and they tended to increase as the AER and product of the initial reactant concentrations increased. Compared to our similar research on limonene ozonolysis (Youssefi and Waring, 2014), for which formation strength was driven by secondary ozone reactions, the AER impact for α-pinene was opposite in direction and weaker, while the initial reactant product impact was in the same direction but stronger for α-pinene than for limonene. Linear fits of AMFs for α-pinene ozonolysis as a function of the AER and initial reactant concentrations are provided so that future indoor models can predict SOA formation strength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160000353','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160000353"><span><span class="hlt">Air</span> <span class="hlt">Mass</span> Origin in the Arctic and its Response to Future Warming</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Orbe, Clara; Newman, Paul A.; Waugh, Darryn W.; Holzer, Mark; Oman, Luke; Polvani, Lorenzo M.; Li, Feng</p> <p>2014-01-01</p> <p>We present the first climatology of <span class="hlt">air</span> <span class="hlt">mass</span> origin in the Arctic in terms of rigorously defined <span class="hlt">air</span> <span class="hlt">mass</span> fractions that partition <span class="hlt">air</span> according to where it last contacted the planetary boundary layer (PBL). Results from a present-day climate integration of the GEOSCCM general circulation model reveal that the Arctic lower troposphere below 700 mb is dominated year round by <span class="hlt">air</span> whose last PBL contact occurred poleward of 60degN, (Arctic <span class="hlt">air</span>, or <span class="hlt">air</span> of Arctic origin). By comparison, approx. 63% of the Arctic troposphere above 700 mb originates in the NH midlatitude PBL, (midlatitude <span class="hlt">air</span>). Although seasonal changes in the total fraction of midlatitude <span class="hlt">air</span> are small, there are dramatic changes in where that <span class="hlt">air</span> last contacted the PBL, especially above 700 mb. Specifically, during winter <span class="hlt">air</span> in the Arctic originates preferentially over the oceans, approx. 26% in the East Pacific, and approx. 20% in the Atlantic PBL. By comparison, during summer <span class="hlt">air</span> in the Arctic last contacted the midlatitude PBL primarily over land, overwhelmingly so in Asia (approx. 40 %) and, to a lesser extent, in North America (approx. 24%). Seasonal changes in <span class="hlt">air-mass</span> origin are interpreted in terms of seasonal variations in the large-scale ventilation of the midlatitude boundary layer and lower troposphere, namely changes in the midlatitude tropospheric jet and associated transient eddies during winter and large scale convective motions over midlatitudes during summer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54..305C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54..305C"><span>Experimental study on heat transfer performance of fin-tube <span class="hlt">exchanger</span> and PSHE for waste heat recovery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Ting; Bae, Kyung Jin; Kwon, Oh Kyung</p> <p>2018-02-01</p> <p>In this paper, heat transfer characteristics of fin-tube heat <span class="hlt">exchanger</span> and primary surface heat <span class="hlt">exchanger</span> (PSHE) used in waste heat recovery were investigated experimentally. The flow in the fin-tube heat <span class="hlt">exchanger</span> is cross flow and in PSHE counter flow. The variations of friction factor and Colburn j factor with <span class="hlt">air</span> <span class="hlt">mass</span> flow rate, and Nu number with Re number are presented. Various comparison methods are used to evaluate heat transfer performance, and the results show that the heat transfer rate of the PSHE is on average 17.3% larger than that of fin-tube heat <span class="hlt">exchanger</span> when <span class="hlt">air</span> <span class="hlt">mass</span> flow rate is ranging from 1.24 to 3.45 kg/min. However, the PSHE causes higher pressure drop, and the fin-tube heat <span class="hlt">exchanger</span> has a wider application range which leads to a 31.7% higher value of maximum heat transfer rate compared to that of the PSHE. Besides, under the same fan power per unit frontal surface, a higher heat transfer rate value is given in the fin-tube heat <span class="hlt">exchanger</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1046750','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1046750"><span>Stirling <span class="hlt">Air</span> Conditioner for Compact Cooling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>None</p> <p>2010-09-01</p> <p>BEETIT Project: Infinia is developing a compact <span class="hlt">air</span> conditioner that uses an unconventional high efficient Stirling cycle system (vs. conventional vapor compression systems) to produce cool <span class="hlt">air</span> that is energy efficient and does not rely on polluting refrigerants. The Stirling cycle system is a type of <span class="hlt">air</span> conditioning system that uses a motor with a piston to remove heat to the outside atmosphere using a gas refrigerant. To date, Stirling systems have been expensive and have not had the right kind of heat <span class="hlt">exchanger</span> to help cool <span class="hlt">air</span> efficiently. Infinia is using chip cooling technology from the computer industry tomore » make improvements to the heat <span class="hlt">exchanger</span> and improve system performance. Infinia’s <span class="hlt">air</span> conditioner uses helium gas as refrigerant, an environmentally benign gas that does not react with other chemicals and does not burn. Infinia’s improvements to the Stirling cycle system will enable the cost-effective <span class="hlt">mass</span> production of high-efficiency <span class="hlt">air</span> conditioners that use no polluting refrigerants.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991Metro..28...45G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991Metro..28...45G"><span>Experimental Determination of <span class="hlt">Air</span> Density Using a 1 kg <span class="hlt">Mass</span> Comparator in Vacuum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gläser, M.; Schwartz, R.; Mecke, M.</p> <p>1991-01-01</p> <p>The density of ambient <span class="hlt">air</span> has been determined by a straightforward experimental method. The apparent <span class="hlt">masses</span> of two artefacts having about the same <span class="hlt">mass</span> and surface, but different well-known volumes, have been compared by using a 1 kg balance in vacuum and in <span class="hlt">air</span>. The differences of apparent <span class="hlt">masses</span> and volumes yield the <span class="hlt">air</span> density with a relative uncertainty (1σ) of 5 × 10-5. From measurements made using a third artefact, surface sorption effects caused by the change between vacuum and <span class="hlt">air</span> conditions gave a coefficient of about 0,2 μg cm-2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ECSS..176....1M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ECSS..176....1M"><span>Temporal variability of <span class="hlt">air</span>-sea CO2 <span class="hlt">exchange</span> in a low-emission estuary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mørk, Eva Thorborg; Sejr, Mikael Kristian; Stæhr, Peter Anton; Sørensen, Lise Lotte</p> <p>2016-07-01</p> <p>There is the need for further study of whether global estimates of <span class="hlt">air</span>-sea CO2 <span class="hlt">exchange</span> in estuarine systems capture the relevant temporal variability and, as such, the temporal variability of bulk parameterized and directly measured CO2 fluxes was investigated in the Danish estuary, Roskilde Fjord. The <span class="hlt">air</span>-sea CO2 fluxes showed large temporal variability across seasons and between days and that more than 30% of the net CO2 emission in 2013 was a result of two large fall and winter storms. The diurnal variability of ΔpCO2 was up to 400 during summer changing the estuary from a source to a sink of CO2 within the day. Across seasons the system was suggested to change from a sink of atmospheric CO2 during spring to near neutral during summer and later to a source of atmospheric CO2 during fall. Results indicated that Roskilde Fjord was an annual low-emission estuary, with an estimated bulk parameterized release of 3.9 ± 8.7 mol CO2 m-2 y-1 during 2012-2013. It was suggested that the production-respiration balance leading to the low annual emission in Roskilde Fjord, was caused by the shallow depth, long residence time and high water quality in the estuary. In the data analysis the eddy covariance CO2 flux samples were filtered according to the H2Osbnd CO2 cross-sensitivity assessment suggested by Landwehr et al. (2014). This filtering reduced episodes of contradicting directions between measured and bulk parameterized <span class="hlt">air</span>-sea CO2 <span class="hlt">exchanges</span> and changed the net <span class="hlt">air</span>-sea CO2 <span class="hlt">exchange</span> from an uptake to a release. The CO2 gas transfer velocity was calculated from directly measured CO2 fluxes and ΔpCO2 and agreed to previous observations and parameterizations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPSJ...86a4003N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPSJ...86a4003N"><span>General Formalism of <span class="hlt">Mass</span> Scaling Approach for Replica-<span class="hlt">Exchange</span> Molecular Dynamics and its Application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nagai, Tetsuro</p> <p>2017-01-01</p> <p>Replica-<span class="hlt">exchange</span> molecular dynamics (REMD) has demonstrated its efficiency by combining trajectories of a wide range of temperatures. As an extension of the method, the author formalizes the <span class="hlt">mass</span>-manipulating replica-<span class="hlt">exchange</span> molecular dynamics (MMREMD) method that allows for arbitrary <span class="hlt">mass</span> scaling with respect to temperature and individual particles. The formalism enables the versatile application of <span class="hlt">mass</span>-scaling approaches to the REMD method. The key change introduced in the novel formalism is the generalized rules for the velocity and momentum scaling after accepted replica-<span class="hlt">exchange</span> attempts. As an application of this general formalism, the refinement of the viscosity-REMD (V-REMD) method [P. H. Nguyen, <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1063/1.3369626" xlink:type="simple">J. Chem. Phys. 132, 144109 (2010)</ext-link>] is presented. Numerical results are provided using a pilot system, demonstrating easier and more optimized applicability of the new version of V-REMD as well as the importance of adherence to the generalized velocity scaling rules. With the new formalism, more sound and efficient simulations will be performed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..122.7664L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..122.7664L"><span>Atmospheric deposition and <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> fluxes of DDT and HCH in the Yangtze River Estuary, East China Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Zhongxia; Lin, Tian; Li, Yuanyuan; Jiang, Yuqing; Guo, Zhigang</p> <p>2017-07-01</p> <p>The Yangtze River Estuary (YRE) is strongly influenced by the Yangtze River and lies on the pathway of the East Asian Monsoon. This study examined atmospheric deposition and <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> fluxes of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) to determine whether the YRE is a sink or source of selected pesticides at the <span class="hlt">air</span>-water interface under the influences of river input and atmospheric transport. The <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> of DDT was characterized by net volatilization with a marked difference in its fluxes between summer (140 ng/m2/d) and the other three seasons (12 ng/m2/d), possibly due to the high surface seawater temperatures and larger riverine input in summer. However, there was no obvious seasonal variation in the atmospheric HCH deposition, and the <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> reached equilibrium because of low HCH levels in the <span class="hlt">air</span> and seawater after the long-term banning of HCH and the degradation. The gas <span class="hlt">exchange</span> flux of HCH was comparable to the dry and wet deposition fluxes at the <span class="hlt">air</span>-water interface. This suggests that the influences from the Yangtze River input and East Asian continental outflow on the fate of HCH in the YRE were limited. The gas <span class="hlt">exchange</span> flux of DDT was about fivefold higher than the total dry and wet deposition fluxes. DDT residues in agricultural soil transported by enhanced riverine runoff were responsible for sustaining such a high net volatilization in summer. Moreover, our results indicated that there were fresh sources of DDT from the local environment to sustain net volatilization throughout the year.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/513622','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/513622"><span>The fabrication of plastic cages for suspension in <span class="hlt">mass</span> <span class="hlt">air</span> flow racks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nielsen, F H; Bailey, B</p> <p>1979-08-01</p> <p>A cage for suspension in <span class="hlt">mass</span> <span class="hlt">air</span> flow racks was constructed of plastic and used to house rats. Little or no difficulty was encountered with the <span class="hlt">mass</span> <span class="hlt">air</span> flow rack-suspended cage system during the 4 years it was used for the study of trace elements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22145748','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22145748"><span>Selective permeation of moisture and VOCs through polymer membranes used in total heat <span class="hlt">exchangers</span> for indoor <span class="hlt">air</span> ventilation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, L-Z; Zhang, X-R; Miao, Q-Z; Pei, L-X</p> <p>2012-08-01</p> <p>Fresh <span class="hlt">air</span> ventilation is central to indoor environmental control. Total heat <span class="hlt">exchangers</span> can be key equipment for energy conservation in ventilation. Membranes have been used for total heat <span class="hlt">exchangers</span> for more than a decade. Much effort has been spent to achieve water vapor permeability of various membranes; however, relatively little attention has been paid to the selectivity of moisture compared with volatile organic compounds (VOCs) through such membranes. In this investigation, the most commonly used membranes, both hydrophilic and hydrophobic ones, are tested for their permeability for moisture and five VOCs (acetic acid, formaldehyde, acetaldehyde, toluene, and ethane). The selectivity of moisture vs. VOCs in these membranes is then evaluated. With a solution-diffusion model, the solubility and diffusivity of moisture and VOCs in these membranes are calculated. The resulting data could provide some reference for future material selection. Total heat <span class="hlt">exchangers</span> are important equipment for fresh <span class="hlt">air</span> ventilation with energy conservation. However, their implications for indoor <span class="hlt">air</span> quality in terms of volatile organic compound permeation have not been known. The data in this article help us to clarify the impacts on indoor VOC levels of membrane-based heat <span class="hlt">exchangers</span>. Guidelines for material selection can be obtained for future use total heat <span class="hlt">exchangers</span> for building ventilation. © 2011 John Wiley & Sons A/S.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140007297','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140007297"><span>A Comparison of the Red Green Blue <span class="hlt">Air</span> <span class="hlt">Mass</span> Imagery and Hyperspectral Infrared Retrieved Profiles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berndt, E. B.; Folmer, Michael; Dunion, Jason</p> <p>2014-01-01</p> <p>The Red Green Blue (RGB) <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery is derived from multiple channels or paired channel differences. Multiple channel products typically provide additional information than a single channel can provide alone. The RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery simplifies the interpretation of temperature and moisture characteristics of <span class="hlt">air</span> <span class="hlt">masses</span> surrounding synoptic and mesoscale features. Despite the ease of interpretation of multiple channel products, the combination of channels and channel differences means the resulting product does not represent a quantity or physical parameter such as brightness temperature in conventional single channel satellite imagery. Without a specific quantity to reference, forecasters are often confused as to what RGB products represent. Hyperspectral infrared retrieved profiles of temperature, moisture, and ozone can provide insight about the <span class="hlt">air</span> <span class="hlt">mass</span> represented on the RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> product and provide confidence in the product and representation of <span class="hlt">air</span> <span class="hlt">masses</span> despite the lack of a quantity to reference for interpretation. This study focuses on RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> analysis of Hurricane Sandy as it moved north along the U.S. East Coast, while transitioning to a hybrid extratropical storm. Soundings and total column ozone retrievals were analyzed using data from the Cross-track Infrared and Advanced Technology Microwave Sounder Suite (CrIMSS) on the Suomi National Polar Orbiting Partnership satellite and the Atmospheric Infrared Sounder (<span class="hlt">AIRS</span>) on the National Aeronautics and Space Administration Aqua satellite along with dropsondes that were collected from National Oceanic and Atmospheric Administration and <span class="hlt">Air</span> Force research aircraft. By comparing these datasets to the RGB <span class="hlt">Air</span> <span class="hlt">Mass</span>, it is possible to capture quantitative information that could help in analyzing the synoptic environment enough to diagnose the onset of extratropical transition. This was done by identifying any stratospheric <span class="hlt">air</span> intrusions (SAIs) that existed in the vicinity of Sandy as the wind</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27974151','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27974151"><span>Using a passive <span class="hlt">air</span> sampler to monitor <span class="hlt">air</span>-soil <span class="hlt">exchange</span> of organochlorine pesticides in the pasture of the central Tibetan Plateau.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Chuanfei; Wang, Xiaoping; Ren, Jiao; Gong, Ping; Yao, Tandong</p> <p>2017-02-15</p> <p><span class="hlt">Air</span>-soil <span class="hlt">exchange</span> is a key process controlling the fate of persistent organic pollutants (POPs). However, the "sink effect" of soil for POPs in Tibetan pasture has not been clear. In NamCo, in the central Tibetan Plateau (TP) where the land is covered by grass, a modified passive <span class="hlt">air</span> sampler (PAS) (thickness: 2cm) was tested. Using the PAS, the atmospheric gaseous phase organochlorine pesticides (OCPs) at 11 heights from close-to-surface (2cm) to 200cm above ground, in summer and in winter, were measured. Concentrations of OCPs in summer were higher than those in winter. Both in summer and winter, atmospheric concentrations of OCPs decreased with decreasing height from 200 to 2cm, indicating that OCPs were being deposited from <span class="hlt">air</span> to soil. <span class="hlt">Air</span> deposition of OCPs was possibly driven by wind speed. Furthermore, based on <span class="hlt">air</span> OCPs at 0-3cm near the surface, the interface <span class="hlt">exchange</span> of OCPs between <span class="hlt">air</span> and soil was studied by the fugacity method. The results showed that pastural soil in the TP was a "sink" of OCPs even in summer. The mean deposition fluxes of α-HCH, γ-HCH and o,p'-DDT were 0.72, 0.24 and 0.54pg/h/m 2 , respectively, and it was estimated that the level of these pollutants in the soil will double every 24, 66 and 206years, respectively. This study will contribute to the further understanding of global cycling of POPs in different land covers. Copyright © 2016 Elsevier B.V. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869090','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869090"><span>Self-defrosting recuperative <span class="hlt">air-to-air</span> heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Drake, Richard L.</p> <p>1993-01-01</p> <p>A heat <span class="hlt">exchanger</span> includes a stationary spirally or concentrically wound heat <span class="hlt">exchanger</span> core with rotating baffles on upper and lower ends thereof. The rotating baffles include rotating inlets and outlets which are in communication with respective fixed inlets and outlets via annuli. The rotation of the baffles causes a concurrent rotation of the temperature distribution within the stationary <span class="hlt">exchanger</span> core, thereby preventing frost build-up in some applications and preventing the formation of hot spots in other applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1745b0002B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1745b0002B"><span>CFD analysis of the plate heat <span class="hlt">exchanger</span> - Mathematical modelling of <span class="hlt">mass</span> and heat transfer in serial connection with tubular heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bojko, Marian; Kocich, Radim</p> <p>2016-06-01</p> <p>Application of numerical simulations based on the CFD calculation when the <span class="hlt">mass</span> and heat transfer between the fluid flows is essential component of thermal calculation. In this article the mathematical model of the heat <span class="hlt">exchanger</span> is defined, which is subsequently applied to the plate heat <span class="hlt">exchanger</span>, which is connected in series with the other heat <span class="hlt">exchanger</span> (tubular heat <span class="hlt">exchanger</span>). The present contribution deals with the possibility to use the waste heat of the flue gas produced by small micro turbine. Inlet boundary conditions to the mathematical model of the plate heat <span class="hlt">exchanger</span> are obtained from the results of numerical simulation of the tubular heat <span class="hlt">exchanger</span>. Required parameters such for example inlet temperature was evaluated from temperature field, which was subsequently imported to the inlet boundary condition to the simulation of plate heat <span class="hlt">exchanger</span>. From the results of 3D numerical simulations are evaluated basic flow variables including the evaluation of dimensionless parameters such as Colburn j-factor and friction ft factor. Numerical simulation is realized by software ANSYS Fluent15.0.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900034024&hterms=mass+fraction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dmass%2Bfraction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900034024&hterms=mass+fraction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dmass%2Bfraction"><span>Dynamic <span class="hlt">mass</span> <span class="hlt">exchange</span> in doubly degenerate binaries. I - 0.9 and 1.2 solar <span class="hlt">mass</span> stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benz, W.; Cameron, A. G. W.; Press, W. H.; Bowers, R. L.</p> <p>1990-01-01</p> <p>The dynamic <span class="hlt">mass</span> <span class="hlt">exchange</span> process in doubly degenerate binaries was investigated using a three-dimensional numerical simulation of the evolution of a doubly degenerate binary system in which the primary is a 1.2-solar-<span class="hlt">mass</span> white dwarf and the Roche lobe filling secondary is a 0.9-solar-<span class="hlt">mass</span> dwarf. The results show that, in a little more than two orbital periods, the secondary is completely destroyed and transformed into a thick disk orbiting about the primary. Since only a very small fraction of the <span class="hlt">mass</span> (0.0063 solar <span class="hlt">mass</span>) escapes the system, the evolution of the binary results in the formation of a massive object. This object is composed of three parts, the initial white dwarf primary, a very hot pressure-supported spherical envelope, and a rotationally supported outer disk. The evolution of the system can be understood in terms of a simple analytical model where it is shown that the angular momentum carried by the <span class="hlt">mass</span> during the transfer and stored in the disk determines the evolution of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25318698','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25318698"><span>Time-resolved pulsed hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry probes gaseous proteins structural kinetics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rajabi, Khadijeh</p> <p>2015-01-01</p> <p>A pulsed hydrogen/deuterium <span class="hlt">exchange</span> (HDX) method has been developed for rapid monitoring of the <span class="hlt">exchange</span> kinetics of protein ions with D2O a few milliseconds after electrospray ionization (ESI). The stepwise gradual evolution of HDX of multiply charged protein ions was monitored using the pulsed HDX <span class="hlt">mass</span> spectrometry technique. Upon introducing a very short pulse of D2O (in the μs to ms time scale) into the linear ion trap (LIT) of a time-of-flight (TOF) <span class="hlt">mass</span> spectrometer, bimodal distributions were detected for the ions of cytochrome c and ubiquitin. Mechanistic details of HDX reactions for ubiquitin and cytochrome c in the gas phase were uncovered and the structural transitions were followed by analyzing the kinetics of HDX.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/143941','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/143941"><span>Self-defrosting recuperative <span class="hlt">air-to-air</span> heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Drake, R.L.</p> <p>1993-12-28</p> <p>A heat <span class="hlt">exchanger</span> is described which includes a stationary spirally or concentrically wound heat <span class="hlt">exchanger</span> core with rotating baffles on upper and lower ends thereof. The rotating baffles include rotating inlets and outlets which are in communication with respective fixed inlets and outlets via annuli. The rotation of the baffles causes a concurrent rotation of the temperature distribution within the stationary <span class="hlt">exchanger</span> core, thereby preventing frost build-up in some applications and preventing the formation of hot spots in other applications. 3 figures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26388365','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26388365"><span>Direct analysis of ultra-trace semiconductor gas by inductively coupled plasma <span class="hlt">mass</span> spectrometry coupled with gas to particle conversion-gas <span class="hlt">exchange</span> technique.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ohata, Masaki; Sakurai, Hiromu; Nishiguchi, Kohei; Utani, Keisuke; Günther, Detlef</p> <p>2015-09-03</p> <p>An inductively coupled plasma <span class="hlt">mass</span> spectrometry (ICPMS) coupled with gas to particle conversion-gas <span class="hlt">exchange</span> technique was applied to the direct analysis of ultra-trace semiconductor gas in ambient <span class="hlt">air</span>. The ultra-trace semiconductor gases such as arsine (AsH3) and phosphine (PH3) were converted to particles by reaction with ozone (O3) and ammonia (NH3) gases within a gas to particle conversion device (GPD). The converted particles were directly introduced and measured by ICPMS through a gas <span class="hlt">exchange</span> device (GED), which could penetrate the particles as well as <span class="hlt">exchange</span> to Ar from either non-reacted gases such as an <span class="hlt">air</span> or remaining gases of O3 and NH3. The particle size distribution of converted particles was measured by scanning mobility particle sizer (SMPS) and the results supported the elucidation of particle agglomeration between the particle converted from semiconductor gas and the particle of ammonium nitrate (NH4NO3) which was produced as major particle in GPD. Stable time-resolved signals from AsH3 and PH3 in <span class="hlt">air</span> were obtained by GPD-GED-ICPMS with continuous gas introduction; however, the slightly larger fluctuation, which could be due to the ionization fluctuation of particles in ICP, was observed compared to that of metal carbonyl gas in Ar introduced directly into ICPMS. The linear regression lines were obtained and the limits of detection (LODs) of 1.5 pL L(-1) and 2.4 nL L(-1) for AsH3 and PH3, respectively, were estimated. Since these LODs revealed sufficiently lower values than the measurement concentrations required from semiconductor industry such as 0.5 nL L(-1) and 30 nL L(-1) for AsH3 and PH3, respectively, the GPD-GED-ICPMS could be useful for direct and high sensitive analysis of ultra-trace semiconductor gas in <span class="hlt">air</span>. Copyright © 2015 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54..803D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54..803D"><span>Experimental evaluation of refrigerant <span class="hlt">mass</span> charge and ambient <span class="hlt">air</span> temperature effects on performance of <span class="hlt">air</span>-conditioning systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deymi-Dashtebayaz, Mahdi; Farahnak, Mehdi; Moraffa, Mojtaba; Ghalami, Arash; Mohammadi, Nima</p> <p>2018-03-01</p> <p>In this paper the effects of refrigerant charge amount and ambient <span class="hlt">air</span> temperature on performance and thermodynamic condition of refrigerating cycle in the split type <span class="hlt">air</span>-conditioner have been investigated. Optimum <span class="hlt">mass</span> charge is the point at which the energy efficiency ratio (EER) of refrigeration cycle becomes the maximum. Experiments have been conducted over a range of refrigerant <span class="hlt">mass</span> charge from 540 to 840 g and a range of ambient temperature from 27 to 45 °C, in a 12,000 Btu/h split <span class="hlt">air</span>-conditioner as case study. The various parameters have been considered to evaluate the cooling rate, energy efficiency ratio (EER), <span class="hlt">mass</span> charge effect and thermodynamic cycle of refrigeration system with R22 refrigerant gas. Results confirmed that the lack of appropriate refrigerant <span class="hlt">mass</span> charge causes the refrigeration system not to reach its maximum cooling capacity. The highest cooling capacity achieved was 3.2 kW (11,000 Btu/h). The optimum <span class="hlt">mass</span> charge and corresponding EER of studied system have been obtained about 640 g and 2.5, respectively. Also, it is observed that EER decreases by 30% as ambient temperature increases from 27 °C to 45 °C. By optimization of the refrigerant <span class="hlt">mass</span> charge in refrigerating systems, about 785 GWh per year of electric energy can be saved in Iran's residential sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......178W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......178W"><span>Aqueous turbulence structure immediately adjacent to the <span class="hlt">air</span> - water interface and interfacial gas <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Binbin</p> <p></p> <p><span class="hlt">Air</span>-sea interaction and the interfacial <span class="hlt">exchange</span> of gas across the <span class="hlt">air</span>-water interface are of great importance in coupled atmospheric-oceanic environmental systems. Aqueous turbulence structure immediately adjacent to the <span class="hlt">air</span>-water interface is the combined result of wind, surface waves, currents and other environmental forces and plays a key role in energy budgets, gas fluxes and hence the global climate system. However, the quantification of turbulence structure sufficiently close to the <span class="hlt">air</span>-water interface is extremely difficult. The physical relationship between interfacial gas <span class="hlt">exchange</span> and near surface turbulence remains insufficiently investigated. This dissertation aims to measure turbulence in situ in a complex environmental forcing system on Lake Michigan and to reveal the relationship between turbulent statistics and the CO2 flux across the <span class="hlt">air</span>-water interface. The major objective of this dissertation is to investigate the physical control of the interfacial gas <span class="hlt">exchange</span> and to provide a universal parameterization of gas transfer velocity from environmental factors, as well as to propose a mechanistic model for the global CO2 flux that can be applied in three dimensional climate-ocean models. Firstly, this dissertation presents an advanced measurement instrument, an in situ free floating Particle Image Velocimetry (FPIV) system, designed and developed to investigate the small scale turbulence structure immediately below the <span class="hlt">air</span>-water interface. Description of hardware components, design of the system, measurement theory, data analysis procedure and estimation of measurement error were provided. Secondly, with the FPIV system, statistics of small scale turbulence immediately below the <span class="hlt">air</span>-water interface were investigated under a variety of environmental conditions. One dimensional wave-number spectrum and structure function sufficiently close to the water surface were examined. The vertical profiles of turbulent dissipation rate were intensively studied</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1421910-importance-heat-mass-transfer-resistances-internally-cooled-liquid-desiccant-dehumidifiers-regenerators','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1421910-importance-heat-mass-transfer-resistances-internally-cooled-liquid-desiccant-dehumidifiers-regenerators"><span>On the importance of the heat and <span class="hlt">mass</span> transfer resistances in internally-cooled liquid desiccant dehumidifiers and regenerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Woods, Jason; Kozubal, Eric</p> <p>2018-02-06</p> <p>Liquid desiccant heat and <span class="hlt">mass</span> <span class="hlt">exchangers</span> are a promising technology for efficient humidity control in buildings. Many researchers have investigated these <span class="hlt">exchangers</span>, often using numerical models to predict their performance. However, there is a lack of information in the literature on the magnitude of the heat and <span class="hlt">mass</span> transfer resistances, both for the dehumidifier (which absorbs moisture from the <span class="hlt">air</span>) and the regenerator (which heats the liquid desiccant to re-concentrate it). This article focuses on internally-cooled, 3-fluid <span class="hlt">exchangers</span> in a parallel plate geometry. Water heats or cools a desiccant across a plate, and the desiccant absorbs or releases water intomore » an airstream through a membrane. A sensitivity analysis was used to estimate the importance of each of the heat and <span class="hlt">mass</span> transfer resistances (<span class="hlt">air</span>, membrane, desiccant, plate, water), and how it changes with different design geometries. The results show that, for most designs, the latent and sensible heat transfer of the dehumidifier is dominated by the <span class="hlt">air</span> <span class="hlt">mass</span> transfer resistance and <span class="hlt">air</span> heat transfer resistance, respectively. The <span class="hlt">air</span> <span class="hlt">mass</span> transfer resistance is also important for the regenerator, but much less so; the change in the desiccant equilibrium humidity ratio due to a change in either temperature or desiccant <span class="hlt">mass</span> fraction is much higher at the regenerator's higher temperatures. This increases the importance of (1) getting heat from the water to the desiccant/membrane interface, and (2) diffusing salt ions quickly away from the desiccant/membrane interface. The membrane heat transfer and water heat transfer resistances were found to be the least important. These results can help inform decisions about what simplifying assumptions to make in numerical models, and can also help in designing these <span class="hlt">exchangers</span> by understanding which resistances are most important.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1421910-importance-heat-mass-transfer-resistances-internally-cooled-liquid-desiccant-dehumidifiers-regenerators','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1421910-importance-heat-mass-transfer-resistances-internally-cooled-liquid-desiccant-dehumidifiers-regenerators"><span>On the importance of the heat and <span class="hlt">mass</span> transfer resistances in internally-cooled liquid desiccant dehumidifiers and regenerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Woods, Jason; Kozubal, Eric</p> <p></p> <p>Liquid desiccant heat and <span class="hlt">mass</span> <span class="hlt">exchangers</span> are a promising technology for efficient humidity control in buildings. Many researchers have investigated these <span class="hlt">exchangers</span>, often using numerical models to predict their performance. However, there is a lack of information in the literature on the magnitude of the heat and <span class="hlt">mass</span> transfer resistances, both for the dehumidifier (which absorbs moisture from the <span class="hlt">air</span>) and the regenerator (which heats the liquid desiccant to re-concentrate it). This article focuses on internally-cooled, 3-fluid <span class="hlt">exchangers</span> in a parallel plate geometry. Water heats or cools a desiccant across a plate, and the desiccant absorbs or releases water intomore » an airstream through a membrane. A sensitivity analysis was used to estimate the importance of each of the heat and <span class="hlt">mass</span> transfer resistances (<span class="hlt">air</span>, membrane, desiccant, plate, water), and how it changes with different design geometries. The results show that, for most designs, the latent and sensible heat transfer of the dehumidifier is dominated by the <span class="hlt">air</span> <span class="hlt">mass</span> transfer resistance and <span class="hlt">air</span> heat transfer resistance, respectively. The <span class="hlt">air</span> <span class="hlt">mass</span> transfer resistance is also important for the regenerator, but much less so; the change in the desiccant equilibrium humidity ratio due to a change in either temperature or desiccant <span class="hlt">mass</span> fraction is much higher at the regenerator's higher temperatures. This increases the importance of (1) getting heat from the water to the desiccant/membrane interface, and (2) diffusing salt ions quickly away from the desiccant/membrane interface. The membrane heat transfer and water heat transfer resistances were found to be the least important. These results can help inform decisions about what simplifying assumptions to make in numerical models, and can also help in designing these <span class="hlt">exchangers</span> by understanding which resistances are most important.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860008821','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860008821"><span>Aeorodynamic characteristics of an <span class="hlt">air-exchanger</span> system for the 40- by 80-foot wind tunnel at Ames Research Center</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rossow, V. J.; Schmidt, G. I.; Meyn, L. A.; Ortner, K. R.; Holmes, R. E.</p> <p>1986-01-01</p> <p>A 1/50-scale model of the 40- by 80-Foot Wind Tunnel at Ames Research Center was used to study various <span class="hlt">air-exchange</span> configurations. System components were tested throughout a range of parameters, and approximate analytical relationships were derived to explain the observed characteristics. It is found that the efficiency of the <span class="hlt">air</span> <span class="hlt">exchanger</span> could be increased (1) by adding a shaped wall to smoothly turn the incoming <span class="hlt">air</span> downstream, (2) by changing to a contoured door at the inlet to control the flow rate, and (3) by increasing the size of the exhaust opening. The static pressures inside the circuit then remain within the design limits at the higher tunnel speeds if the <span class="hlt">air-exchange</span> rate is about 5% or more. Since the model is much smaller than the full-scale facility, it is not possible to completely duplicate the tunnel, and it will be necessary to measure such characteristics as flow rate and tunnel pressures during implementation of the remodeled facility. The aerodynamic loads estimated for the inlet door and for nearby walls are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20050153817&hterms=1074&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231074','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050153817&hterms=1074&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231074"><span>The <span class="hlt">mass</span> and speed dependence of meteor <span class="hlt">air</span> plasma temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jenniskens, Peter; Laux, Christophe O.; Wilson, Michael A.; Schaller, Emily L.</p> <p>2004-01-01</p> <p>The speed and <span class="hlt">mass</span> dependence of meteor <span class="hlt">air</span> plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various <span class="hlt">air</span> plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid <span class="hlt">mass</span> and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and <span class="hlt">masses</span> between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher <span class="hlt">air</span> plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15104905','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15104905"><span>The <span class="hlt">mass</span> and speed dependence of meteor <span class="hlt">air</span> plasma temperatures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jenniskens, Peter; Laux, Christophe O; Wilson, Michael A; Schaller, Emily L</p> <p>2004-01-01</p> <p>The speed and <span class="hlt">mass</span> dependence of meteor <span class="hlt">air</span> plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various <span class="hlt">air</span> plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid <span class="hlt">mass</span> and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and <span class="hlt">masses</span> between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher <span class="hlt">air</span> plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26995905','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26995905"><span>[Effect of <span class="hlt">air</span> temperature and rainfall on wetland ecosystem CO2 <span class="hlt">exchange</span> in China].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chu, Xiao-jing; Han, Guang-xuan</p> <p>2015-10-01</p> <p>Wetland can be a potential efficient sink to reduce global warming due to its higher primary productivity and lower carbon decomposition rate. While there has been a series progress on the influence mechanism of ecosystem CO2 <span class="hlt">exchange</span> over China' s wetlands, a systematic metaanalysis of data still needs to be improved. We compiled data of ecosystem CO2 <span class="hlt">exchange</span> of 21 typical wetland vegetation types in China from 29 papers and carried out an integrated analysis of <span class="hlt">air</span> temperature and precipitation effects on net ecosystem CO2 <span class="hlt">exchange</span> (NEE), ecosystem respiration (Reco), gross primary productivity (GPP), the response of NEE to PAR, and the response of Reco to temperature. The results showed that there were significant responses (P<0.05) of NEE (R2 = 50%, R2=57%), GPP (R2 = 60%, R2 = 50%) Reco (R2 = 44%, R2=50%) with increasing <span class="hlt">air</span> temperature and enhanced precipitation on the annual scale. On the growing season scale, <span class="hlt">air</span> temperature accounted for 50% of the spatial variation of NEE, 36% of GPP and 19% of Reco, respectively. Both NEE (R2 = 33%) and GPP (R2 =25%) were correlated positively with precipitation (P<0.05). However, the relationship between Reco and precipitation was not significant (P>0.05). Across different Chinese wetlands, both precipitation and temperature had no significant effect on apparent quantum yield (α) or ecosystem respiration in the daytime (Reco,day, P>0.05). The maximum photosynthesis rate (Amax) was remarkably correlated with precipitation (P <0.01), but not with <span class="hlt">air</span> temperature. Besides, there was no significant correlation between basal respiration (Rref) and precipitation (P>0.05). Precipitation was negatively correlated with temperature sensitivity of Reco (Q10, P<0.05). Furthermore, temperature accounted for 35% and 46% of the variations in temperature sensitivity of Reco (Q10) and basal respiration (Rref P<0.05), respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950060064&hterms=heat+exchanger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dheat%2Bexchanger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950060064&hterms=heat+exchanger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dheat%2Bexchanger"><span>Analysis of a membrane-based condesate recovery heat <span class="hlt">exchanger</span> (CRX)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Newbold, D.D.</p> <p>1993-01-01</p> <p>The development of a temperature and humidity control system that can remove heat and recover water vapor is key to the development of an Environmental Control and Life Support System (ECLSS). Large quantities of water vapor must be removed from <span class="hlt">air</span>, and this operation has proven difficult in the absense of gravity. This paper presents the modeling results from a program to develop a novel membrane-based heat <span class="hlt">exchanger</span> known as the condensate recovery heat <span class="hlt">exchanger</span> (CRX). This device cools and dehumidifies humid <span class="hlt">air</span> and simultaneously recovers water-vapor condensate. In this paper, the CRX is described and the results of an analysis of the heat- and <span class="hlt">mass</span>-transfer characteristics of the device are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28886873','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28886873"><span>Estimation of <span class="hlt">air</span>-to-grass <span class="hlt">mass</span> interception factors for iodine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karunakara, N; Ujwal, P; Yashodhara, I; Sudeep Kumara, K; Mohan, M P; Bhaskar Shenoy, K; Geetha, P V; Dileep, B N; James, Joshi P; Ravi, P M</p> <p>2018-06-01</p> <p><span class="hlt">Air</span>-to-grass <span class="hlt">mass</span> interception factors for radionuclide are important basic input parameter for the estimation of radiation dose to the public around a nuclear power plant. In this paper, we present the determination of <span class="hlt">air</span>-to- grass <span class="hlt">mass</span> interception factors for iodine using a 2 m × 2 m × 2 m (l × b × h) size environmental chamber. The temperature, humidity, and rainfall inside the environmental chamber was controlled to required values to simulate different environmental conditions. Grass (Pennisetum purpureum, Schum), grown in pots, was kept inside the environmental chamber and stable iodine in elemental form was sublimed quickly inside the chamber to simulate an accidental release of iodine to the environment. The concentration of iodine in the <span class="hlt">air</span> was measured periodically by drawing <span class="hlt">air</span> through a bubbling setup, containing 1% sodium carbonate solution. The <span class="hlt">mass</span> interception factor for dry deposition varied in the range of 0.25-7.7 m 2 kg -1 with mean value of 2.2 m 2 kg -1 with respect to fresh weight of grass, and that due to wet deposition varied in the range of 0.6-4.8 m 2 kg -1 with mean value of 2.3 m 2 kg -1 . The <span class="hlt">mass</span> interception factor was inversely correlated with the total iodine deposited through dry deposition as well as with the rainfall. Copyright © 2017. Published by Elsevier Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28675863','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28675863"><span>Polychlorinated biphenyls in Nepalese surface soils: Spatial distribution, <span class="hlt">air</span>-soil <span class="hlt">exchange</span>, and soil-<span class="hlt">air</span> partitioning.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yadav, Ishwar Chandra; Devi, Ningombam Linthoingambi; Li, Jun; Zhang, Gan</p> <p>2017-10-01</p> <p>Regardless of the ban on the polychlorinated biphenyls (PCBs) decade ago, significant measures of PCBs are still transmitted from essential sources in cities and are all inclusive ecological contaminants around the world. In this study, the concentrations of PCBs in soil, the <span class="hlt">air</span>-soil <span class="hlt">exchange</span> of PCBs, and the soil-<span class="hlt">air</span> partitioning coefficient (K SA ) of PCBs were investigated in four noteworthy urban areas in Nepal. Overall, the concentrations of ∑ 30 PCBs ranged from 10 to 59.4ng/g dry weight; dw (mean 12.2ng/g ±11.2ng/g dw). The hexa-CBs (22-31%) was most dominant among several PCB-homologues, followed by tetra-CBs (20-29%), hepta-CBs (12-21%), penta-CBs (15-17%) and tri-CBs (9-19%). The sources of elevated level of PCBs discharge in Nepalese soil was identified as emission from transformer oil, lubricants, breaker oil, cutting oil and paints, and cable insulation. Slightly strong correlation of PCBs with TOC than BC demonstrated that amorphous organic matter (AOM) assumes a more critical part in holding of PCBs than BC in Nepalese soil. The fugacity fraction (ff) results indicated the soil being the source of PCB in <span class="hlt">air</span> through volatilization and net transport from soil to <span class="hlt">air</span>. The soil-<span class="hlt">air</span> partitioning coefficient study suggests the absorption by soil organic matter control soil-<span class="hlt">air</span> partitioning of PCBs. Slightly weak but positive correlation of measured Log K SA with Log K OA (R 2 = 0.483) and Log K BC-A (R 2 = 0.438) suggests that both Log K OA and Log K BC-A can predict soil-<span class="hlt">air</span> partitioning to lesser extent for PCBs. Copyright © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EPJWC.18002011B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EPJWC.18002011B"><span>The influence of flow modification on <span class="hlt">air</span> and PCM temperatures in an accumulative heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borcuch, Marcin; Musiał, Michał; Sztekler, Karol; Kalawa, Wojciech; Gumuła, Stanisław; Stefański, Sebastian</p> <p>2018-06-01</p> <p>The paper presents the influence of flow modification on the operation of an accumulative heat <span class="hlt">exchanger</span>. This device can be used as a regenerator in ventilation and <span class="hlt">air</span> supply systems. A heat <span class="hlt">exchanger</span> uses ceresine (a mixture of paraffins) as a phase change material (PCM). The aim of this research was to determine the effect of flow modification on temperature distribution and pressure drops in the device. The introduction contains a short description of the test stand used, including the accumulative heat <span class="hlt">exchanger</span>, the guide vanes, and the locations of measurement and control equipment. We found that additional objects limited vortex structures, increased the inside temperature, and dropped the pressure along the heat <span class="hlt">exchanger</span>. Guidelines for further research are proposed and briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1817337G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1817337G"><span>Inter-annual variability of <span class="hlt">air</span> <span class="hlt">mass</span> and acidified pollutants transboundary <span class="hlt">exchange</span> in the north-eastern part of the EANET region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gromov, Sergey A.; Trifonova-Yakovleva, Alisa; Gromov, Sergey S.</p> <p>2016-04-01</p> <p>Anthropogenic emissions, be it exhaust gases or aerosols, stem from multitude of sources and may survive long-range transport within the <span class="hlt">air</span> <span class="hlt">masses</span> they were emitted into. So they follow regional and global transport pathways varying under different climatological regimes. Transboundary transfer of pollutants occurs this way and has a significant impact on the ecological situation of the territories neighbouring those of emission sources, as found in a few earlier studies examining the environmental monitoring data [1]. In this study, we employ a relatively facile though robust technique for estimating the transboundary <span class="hlt">air</span> and concomitant pollutant fluxes using actual or climatological meteorological and <span class="hlt">air</span> pollution monitoring data. Practically, we assume pollutant transfer being proportional to the horizontal transport of <span class="hlt">air</span> enclosed in the lower troposphere and to the concentration of the pollutant of interest. The horizontal transport, in turn, is estimated using the mean layer wind direction and strength, or their descriptive statistics at the individual transects of the boundary of interest. The domain of our interest is the segment of Russian continental border in East Asia spanning from 88° E (southern Middle Siberia) to 135° E (Far East at Pacific shore). The data on atmospheric pollutants concentration are available from the Russian monitoring sites of the region-wide Acid Deposition Monitoring Network in East Asia (EANET, http://www.eanet.asia/) Mondy (Baikal area) and Primorskaya (near Vladivostok). The data comprises multi-year continuous measurement of gas-phase and particulate species abundances in <span class="hlt">air</span> with at least biweekly sampling rate starting from 2000. In the first phase of our study, we used climatological dataset on winds derived from the aerological soundings at Russian stations along the continental border for the 10-year period (1961-1970) by the Research Institute of Hydrometeorological Information - World Data Centre (RIHMI-WDC) [3</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JASMS..23..699V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JASMS..23..699V"><span>Polar Aprotic Modifiers for Chromatographic Separation and Back-<span class="hlt">Exchange</span> Reduction for Protein Hydrogen/Deuterium <span class="hlt">Exchange</span> Monitored by Fourier Transform Ion Cyclotron Resonance <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valeja, Santosh G.; Emmett, Mark R.; Marshall, Alan G.</p> <p>2012-04-01</p> <p>Hydrogen/deuterium <span class="hlt">exchange</span> monitored by <span class="hlt">mass</span> spectrometry is an important non-perturbing tool to study protein structure and protein-protein interactions. However, water in the reversed-phase liquid chromatography mobile phase leads to back-<span class="hlt">exchange</span> of D for H during chromatographic separation of proteolytic peptides following H/D <span class="hlt">exchange</span>, resulting in incorrect identification of fast-<span class="hlt">exchanging</span> hydrogens as unexchanged hydrogens. Previously, fast high-performance liquid chromatography (HPLC) and supercritical fluid chromatography have been shown to decrease back-<span class="hlt">exchange</span>. Here, we show that replacement of up to 40% of the water in the LC mobile phase by the modifiers, dimethylformamide (DMF) and N-methylpyrrolidone (NMP) (i.e., polar organic modifiers that lack rapid <span class="hlt">exchanging</span> hydrogens), significantly reduces back-<span class="hlt">exchange</span>. On-line LC micro-ESI FT-ICR MS resolves overlapped proteolytic peptide isotopic distributions, allowing for quantitative determination of the extent of back-<span class="hlt">exchange</span>. The DMF modified solvent composition also improves chromatographic separation while reducing back-<span class="hlt">exchange</span> relative to conventional solvent.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23157102','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23157102"><span>[Use of the <span class="hlt">air</span>-Q laryngeal airway and tube <span class="hlt">exchanger</span> in a case of difficult tracheal extubation after maxillectomy].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Komasawa, Nobuyasu; Ueki, Ryusuke; Iwasaki, Yohei; Tatara, Tsuneo; Tashiro, Chikara; Kaminoh, Yoshiroh</p> <p>2012-10-01</p> <p>A 79-year-old man was diagnosed with maxillary cancer and underwent total maxillectomy under general anesthesia. The oropharyngeal airway was needed for efficient mask ventilation during anesthesia induction. The maxilla was totally resected and reconstructed with skin from a femoral flap. Tracheal extubation was considered to be difficult given that mask ventilation was contraindicated due to reconstruction of the maxilla. After inserting a tube <span class="hlt">exchanger</span> (TE) into the trachea, the tracheal tube was <span class="hlt">exchanged</span> with an <span class="hlt">air</span>-Q laryngeal airway through the TE. After confirming effective ventilation with the <span class="hlt">air</span>-Q mask, the patient was awakened from anesthesia. We confirmed sufficient spontaneous breathing and no active bleeding in the pharynx. After re-inserting the TE thorough <span class="hlt">air</span>-Q, the <span class="hlt">air</span>-Q was removed, followed by removal of the TE. These findings suggest that the <span class="hlt">air</span>-Q and TE were effective in a case of difficult extubation after maxillectomy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JCoPh.271..172N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JCoPh.271..172N"><span>Reprint of: A numerical modelling of gas <span class="hlt">exchange</span> mechanisms between <span class="hlt">air</span> and turbulent water with an aquarium chemical reaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nagaosa, Ryuichi S.</p> <p>2014-08-01</p> <p>This paper proposes a new numerical modelling to examine environmental chemodynamics of a gaseous material <span class="hlt">exchanged</span> between the <span class="hlt">air</span> and turbulent water phases across a gas-liquid interface, followed by an aquarium chemical reaction. This study uses an extended concept of a two-compartment model, and assumes two physicochemical substeps to approximate the gas <span class="hlt">exchange</span> processes. The first substep is the gas-liquid equilibrium between the <span class="hlt">air</span> and water phases, A(g)⇌A(aq), with Henry's law constant H. The second is a first-order irreversible chemical reaction in turbulent water, A(aq)+H2O→B(aq)+H+ with a chemical reaction rate κA. A direct numerical simulation (DNS) technique has been employed to obtain details of the gas <span class="hlt">exchange</span> mechanisms and the chemical reaction in the water compartment, while zero velocity and uniform concentration of A is considered in the <span class="hlt">air</span> compartment. The study uses the different Schmidt numbers between 1 and 8, and six nondimensional chemical reaction rates between 10(≈0) to 101 at a fixed Reynolds number. It focuses on the effects of the Schmidt number and the chemical reaction rate on fundamental mechanisms of the gas <span class="hlt">exchange</span> processes across the interface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714727E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714727E"><span>Dusty <span class="hlt">air</span> <span class="hlt">masses</span> transport between Amazon Basin and Caribbean Islands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Euphrasie-Clotilde, Lovely; Molinie, Jack; Prospero, Joseph; Feuillard, Tony; Brute, Francenor; Jeannot, Alexis</p> <p>2015-04-01</p> <p>Depend on the month, African desert dust affect different parts of the North Atlantic Ocean. From December to April, Saharan dust outbreaks are often reported over the amazon basin and from May to November over the Caribbean islands and the southern regions of USA. This annual oscillation of Saharan dust presence, related to the ITCZ position, is perturbed some time, during March. Indeed, over Guadeloupe, the <span class="hlt">air</span> quality network observed between 2007 and 2012 several dust events during March. In this paper, using HISPLIT back trajectories, we analyzed <span class="hlt">air</span> <span class="hlt">masses</span> trajectories for March dust events observed in Guadeloupe, from 2007 to 2012.We observed that the high pressure positions over the Atlantic Ocean allow the transport of dusty <span class="hlt">air</span> <span class="hlt">masses</span> from southern region of West Africa to the Caribbean Sea with a path crossing close to coastal region of French Guyana. Complementary investigations including the relationship between PM10 concentrations recorded in two sites Pointe-a-Pitre in the Caribbean, and Cayenne in French Guyana, have been done. Moreover we focus on the mean delay observed between the times arrival. All the results show a link between pathway of dusty <span class="hlt">air</span> <span class="hlt">masses</span> present over amazon basin and over the Caribbean region during several event of March. The next step will be the comparison of mineral dust composition for this particular month.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18640753','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18640753"><span>Dry deposition and soil-<span class="hlt">air</span> gas <span class="hlt">exchange</span> of polychlorinated biphenyls (PCBs) in an industrial area.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bozlaker, Ayse; Odabasi, Mustafa; Muezzinoglu, Aysen</p> <p>2008-12-01</p> <p>Ambient <span class="hlt">air</span> and dry deposition, and soil samples were collected at the Aliaga industrial site in Izmir, Turkey. Atmospheric total (particle+gas) Sigma(41)-PCB concentrations were higher in summer (3370+/-1617 pg m(-3), average+SD) than in winter (1164+/-618 pg m(-3)), probably due to increased volatilization with temperature. Average particulate Sigma(41)-PCBs dry deposition fluxes were 349+/-183 and 469+/-328 ng m(-2) day(-1) in summer and winter, respectively. Overall average particulate deposition velocity was 5.5+/-3.5 cm s(-1). The spatial distribution of Sigma(41)-PCB soil concentrations (n=48) showed that the iron-steel plants, ship dismantling facilities, refinery and petrochemicals complex are the major sources in the area. Calculated <span class="hlt">air</span>-soil <span class="hlt">exchange</span> fluxes indicated that the contaminated soil is a secondary source to the atmosphere for lighter PCBs and as a sink for heavier ones. Comparable magnitude of gas <span class="hlt">exchange</span> and dry particle deposition fluxes indicated that both mechanisms are equally important for PCB movement between <span class="hlt">air</span> and soil in Aliaga.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19766288','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19766288"><span>Modelling bioaccumulation of semi-volatile organic compounds (SOCs) from <span class="hlt">air</span> in plants based on allometric principles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Steyaert, Nils L L; Hauck, Mara; Van Hulle, Stijn W H; Hendriks, A Jan</p> <p>2009-10-01</p> <p>A model was developed for gaseous plant-<span class="hlt">air</span> <span class="hlt">exchange</span> of semi-volatile organic compounds. Based on previous soil-plant modelling, uptake and elimination kinetics were scaled as a function of plant <span class="hlt">mass</span> and octanol-<span class="hlt">air</span> partition ratios. <span class="hlt">Exchange</span> of chemicals was assumed to be limited by resistances encountered during diffusion through a laminar boundary layer of <span class="hlt">air</span> and permeation through the cuticle of the leaf. The uptake rate constant increased and the elimination rate constant decreased with the octanol-<span class="hlt">air</span> partition ratio both apparently levelling off at high values. Differences in kinetics between species could be explained by their <span class="hlt">masses</span>. Validation on independent data showed that bio-concentration factors of PCBs, chlorobenzenes and other chemicals were predicted well by the model. For pesticides, polycyclic aromatic hydrocarbons and dioxins deviations occurred.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JASTP..71.2027A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JASTP..71.2027A"><span>Influence of the relative optical <span class="hlt">air</span> <span class="hlt">mass</span> on ultraviolet erythemal irradiance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antón, M.; Serrano, A.; Cancillo, M. L.; García, J. A.</p> <p>2009-12-01</p> <p>The main objective of this article is to analyze the relationship between the transmissivity for ultraviolet erythemal irradiance (UVER) and the relative optical <span class="hlt">air</span> <span class="hlt">mass</span> at Badajoz (Southwestern Spain). Thus, a power expression between both variables is developed, which analyses in detail how atmospheric transmission is influenced by the total ozone column (TOC) and the atmospheric clearness. The period of analysis extends from 2001 to 2005. The experimental results indicate that clearness conditions play an important role in the relationship between UVER transmissivity and the relative optical <span class="hlt">air</span> <span class="hlt">mass</span>, while the effect of TOC is much smaller for this data set. In addition, the results show that UVER transmissivity is more sensitive to changes in atmospheric clearness than to TOC variability. Changes in TOC values higher than 15% cause UVER trasnmissivity to vary between 14% and 22%, while changes between cloud-free and overcast conditions produce variations in UVER transmissivity between 68% and 74% depending on the relative optical <span class="hlt">air</span> <span class="hlt">mass</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOS.A23A..04C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOS.A23A..04C"><span><span class="hlt">Air</span>-Sea Momentum and Enthalpy <span class="hlt">Exchange</span> in Coupled Atmosphere-Wave-Ocean Modeling of Tropical Cyclones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Curcic, M.; Chen, S. S.</p> <p>2016-02-01</p> <p>The atmosphere and ocean are coupled through momentum, enthalpy, and <span class="hlt">mass</span> fluxes. Accurate representation of these fluxes in a wide range of weather and climate conditions is one of major challenges in prediction models. Their current parameterizations are based on sparse observations in low-to-moderate winds and are not suited for high wind conditions such as tropical cyclones (TCs) and winter storms. In this study, we use the Unified Wave INterface - Coupled Model (UWIN-CM), a high resolution, fully-coupled atmosphere-wave-ocean model, to better understand the role of ocean surface waves in mediating <span class="hlt">air</span>-sea momentum and enthalpy <span class="hlt">exchange</span> in TCs. In particular, we focus on the explicit treatment of wave growth and dissipation for calculating atmospheric and oceanic stress, and its role in upper ocean mixing and surface cooling in the wake of the storm. Wind-wave misalignment and local wave disequilibrium result in difference between atmospheric and oceanic stress being largest on the left side of the storm. We find that explicit wave calculation in the coupled model reduces momentum transfer into the ocean by more than 10% on average, resulting in reduced cooling in TC's wake and subsequent weakening of the storm. We also investigate the impacts of sea surface temperature and upper ocean parameterization on <span class="hlt">air</span>-sea enthalpy fluxes in the fully coupled model. High-resolution UWIN-CM simulations of TCs with various intensities and structure are conducted in this study to better understand the complex TC-ocean interaction and improve the representation of <span class="hlt">air</span>-sea coupling processes in coupled prediction models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC41A0997C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC41A0997C"><span>Defining Winter and Identifying Synoptic <span class="hlt">Air</span> <span class="hlt">Mass</span> Change in the Northeast and Northern Plains U.S. since 1950</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chapman, C. J.; Pennington, D.; Beitscher, M. R.; Godek, M. L.</p> <p>2017-12-01</p> <p>Understanding and forecasting the characteristics of winter weather change in the northern U.S. is vital to regional economy, agriculture, tourism and resident life. This is especially true in the Northeast and Northern Plains where substantial changes to the winter season have already been documented in the atmospheric science and biological literature. As there is no single established definition of `winter', this research attempts to identify the winter season in both regions utilizing a synoptic climatological approach with <span class="hlt">air</span> <span class="hlt">mass</span> frequencies. The Spatial Synoptic Classification is used to determine the daily <span class="hlt">air</span> <span class="hlt">mass</span>/ weather type conditions since 1950 at 40 locations across the two regions. Annual frequencies are first computed as a baseline reference. Then winter <span class="hlt">air</span> <span class="hlt">mass</span> frequencies and departures from normal are calculated to define the season along with the statistical significance. Once the synoptic winter is established, long-term regional changes to the season and significance are explored. As evident global changes have occurred after 1975, an Early period of years prior to 1975 and a Late set for all years following this date are compared. Early and Late record synoptic changes are then examined to assess any thermal and moisture condition changes of the regional winter <span class="hlt">air</span> <span class="hlt">masses</span> over time. Cold to moderately dry <span class="hlt">air</span> <span class="hlt">masses</span> dominate annually in both regions. Northeast winters are also characterized by cold to moderate dry <span class="hlt">air</span> <span class="hlt">masses</span>, with coastal locations experiencing more Moist Polar types. The Northern Plains winters are dominated by cold, dry <span class="hlt">air</span> <span class="hlt">masses</span> in the east and cold to moderate dry <span class="hlt">air</span> <span class="hlt">masses</span> in the west. Prior to 1975, Northeast winters are defined by an increase in cooler and wetter <span class="hlt">air</span> <span class="hlt">masses</span>. Dry Tropical <span class="hlt">air</span> <span class="hlt">masses</span> only occur in this region after 1975. Northern Plains winters are also characterized by more cold, dry <span class="hlt">air</span> <span class="hlt">masses</span> prior to 1975. More Dry Moderate and Moist Moderate <span class="hlt">air</span> <span class="hlt">masses</span> have occurred since 1975. These results</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006GeoRL..3314803Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006GeoRL..3314803Z"><span>Impacts of winter storms on <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Weiqing; Perrie, Will; Vagle, Svein</p> <p>2006-07-01</p> <p>The objective of this study is to investigate <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> during winter storms, using field measurements from Ocean Station Papa in the Northeast Pacific (50°N, 145°W). We show that increasing gas transfer rates are coincident with increasing winds and deepening depth of bubble penetration, and that this process depends on sea state. Wave-breaking is shown to be an important factor in the gas transfer velocity during the peaks of the storms, increasing the flux rates by up to 20%. Gas transfer rates and concentrations can exhibit asymmetry, reflecting a sudden increase with the onset of a storm, and gradual recovery stages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JEPT...89.1369G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JEPT...89.1369G"><span>Heat <span class="hlt">Exchange</span> with <span class="hlt">Air</span> and Temperature Profile of a Moving Oversize Tire</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grinchuk, P. S.; Fisenko, S. P.</p> <p>2016-11-01</p> <p>A one-dimensional mathematical model of heat transfer in a tire with account for the deformation energy dissipation and heat <span class="hlt">exchange</span> of a moving tire with <span class="hlt">air</span> has been developed. The mean temperature profiles are calculated and transition to a stationary thermal regime is considered. The influence of the rate of energy dissipation and of effective thermal conductivity of rubber on the temperature field is investigated quantitatively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910069804&hterms=air+measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dair%2Bmeasurement','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910069804&hterms=air+measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dair%2Bmeasurement"><span><span class="hlt">Air</span> <span class="hlt">mass</span> origins and troposphere-to-stratosphere <span class="hlt">exchange</span> associated with mid-latitude cyclogenesis and tropopause folding inferred from Be-7 measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kritz, Mark A.; Rosner, Stefan W.; Danielsen, Edwin F.; Selkirk, Henry B.</p> <p>1991-01-01</p> <p>The 1984 extratropical mission of NASA's Stratosphere-Troposphere <span class="hlt">Exchange</span> Project (STEP) studied cross-jet transport in regions of cyclogenesis and tropopause folding. Correlations of Be-7, ozone, water vapor, and potential vorticity measured on a NASA U-2 research aircraft flying in high shear regions above the jet core are indicative of mixing between the cyclonic and the anticyclonic sides of the jet and are consistent with the hypothesis that small-scale entrainments of upper tropospheric <span class="hlt">air</span> into the lower stratosphere during cyclogenesis are important in maintaining the vertical gradients of Be-7, ozone, water vapor and other trace constituents in the lower few kilometers of the midlatitude stratosphere. Correlations between Be-7, and ozone suggest a lower tropical stratospheric origin for the ozone-poor lamina observed above the jet core.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25216897','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25216897"><span>Intensification of heat and <span class="hlt">mass</span> transfer by ultrasound: application to heat <span class="hlt">exchangers</span> and membrane separation processes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gondrexon, N; Cheze, L; Jin, Y; Legay, M; Tissot, Q; Hengl, N; Baup, S; Boldo, P; Pignon, F; Talansier, E</p> <p>2015-07-01</p> <p>This paper aims to illustrate the interest of ultrasound technology as an efficient technique for both heat and <span class="hlt">mass</span> transfer intensification. It is demonstrated that the use of ultrasound results in an increase of heat <span class="hlt">exchanger</span> performances and in a possible fouling monitoring in heat <span class="hlt">exchangers</span>. <span class="hlt">Mass</span> transfer intensification was observed in the case of cross-flow ultrafiltration. It is shown that the enhancement of the membrane separation process strongly depends on the physico-chemical properties of the filtered suspensions. Copyright © 2014 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70102289','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70102289"><span><span class="hlt">Air</span>-water gas <span class="hlt">exchange</span> and CO2 flux in a mangrove-dominated estuary</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ho, David T.; Ferrón, Sara; Engel, Victor C.; Larsen, Laurel G.; Barr, Jordan G.</p> <p>2014-01-01</p> <p>Mangrove forests are highly productive ecosystems, but the fate of mangrove-derived carbon remains uncertain. Part of that uncertainty stems from the fact that gas transfer velocities in mangrove-surrounded waters are not well determined, leading to uncertainty in <span class="hlt">air</span>-water CO2 fluxes. Two SF6 tracer release experiments were conducted to determine gas transfer velocities (k(600) = 8.3 ± 0.4 and 8.1 ± 0.6 cm h−1), along with simultaneous measurements of pCO2 to determine the <span class="hlt">air</span>-water CO2 fluxes from Shark River, Florida (232.11 ± 23.69 and 171.13 ± 20.28 mmol C m−2 d−1), an estuary within the largest contiguous mangrove forest in North America. The gas transfer velocity results are consistent with turbulent kinetic energy dissipation measurements, indicating a higher rate of turbulence and gas <span class="hlt">exchange</span> than predicted by commonly used wind speed/gas <span class="hlt">exchange</span> parameterizations. The results have important implications for carbon fluxes in mangrove ecosystems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://lofe.dukejournals.org/content/2/1.abstract','USGSPUBS'); return false;" href="http://lofe.dukejournals.org/content/2/1.abstract"><span><span class="hlt">Air</span>-water oxygen <span class="hlt">exchange</span> in a large whitewater river</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hall, Robert O.; Kennedy, Theodore A.; Rosi-Marshall, Emma J.</p> <p>2012-01-01</p> <p><span class="hlt">Air</span>-water gas <span class="hlt">exchange</span> governs fluxes of gas into and out of aquatic ecosystems. Knowing this flux is necessary to calculate gas budgets (i.e., O2) to estimate whole-ecosystem metabolism and basin-scale carbon budgets. Empirical data on rates of gas <span class="hlt">exchange</span> for streams, estuaries, and oceans are readily available. However, there are few data from large rivers and no data from whitewater rapids. We measured gas transfer velocity in the Colorado River, Grand Canyon, as decline in O2 saturation deficit, 7 times in a 28-km segment spanning 7 rapids. The O2 saturation deficit exists because of hypolimnetic discharge from Glen Canyon Dam, located 25 km upriver from Lees Ferry. Gas transfer velocity (k600) increased with slope of the immediate reach. k600 was -1 in flat reaches, while k600 for the steepest rapid ranged 3600-7700 cm h-1, an extremely high value of k600. Using the rate of gas <span class="hlt">exchange</span> per unit length of water surface elevation (Kdrop, m-1), segment-integrated k600 varied between 74 and 101 cm h-1. Using Kdrop we scaled k600 to the remainder of the Colorado River in Grand Canyon. At the scale corresponding to the segment length where 80% of the O2 <span class="hlt">exchanged</span> with the atmosphere (mean length = 26.1 km), k600 varied 4.5-fold between 56 and 272 cm h-1 with a mean of 113 cm h-1. Gas transfer velocity for the Colorado River was higher than those from other aquatic ecosystems because of large rapids. Our approach of scaling k600 based on Kdrop allows comparing gas transfer velocity across rivers with spatially heterogeneous morphology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16460725','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16460725"><span>Winter <span class="hlt">air-mass</span>-based synoptic climatological approach and hospital admissions for myocardial infarction in Florence, Italy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morabito, Marco; Crisci, Alfonso; Grifoni, Daniele; Orlandini, Simone; Cecchi, Lorenzo; Bacci, Laura; Modesti, Pietro Amedeo; Gensini, Gian Franco; Maracchi, Giampiero</p> <p>2006-09-01</p> <p>The aim of this study was to evaluate the relationship between the risk of hospital admission for myocardial infarction (MI) and the daily weather conditions during the winters of 1998-2003, according to an <span class="hlt">air-mass</span>-based synoptic climatological approach. The effects of time lag and 2-day sequences with specific <span class="hlt">air</span> <span class="hlt">mass</span> types were also investigated. Studies concerning the relationship between atmospheric conditions and human health need to take into consideration simultaneous effects of many weather variables. At the moment few studies have surveyed these effects on hospitalizations for MI. Analyses were concentrated on winter, when the maximum peak of hospitalization occurred. An objective daily <span class="hlt">air</span> <span class="hlt">mass</span> classification by means of statistical analyses based on ground meteorological data was carried out. A comparison between <span class="hlt">air</span> <span class="hlt">mass</span> classification and hospital admissions was made by the calculation of a MI admission index, and to detect significant relationships the Mann-Whitney U test, the analysis of variance, and the Bonferroni test were used. Significant increases in hospital admissions for MI were evident 24h after a day characterized by an anticyclonic continental <span class="hlt">air</span> <span class="hlt">mass</span> and 6 days after a day characterized by a cyclonic <span class="hlt">air</span> <span class="hlt">mass</span>. Increased risk of hospitalization was found even when specific 2-day <span class="hlt">air</span> <span class="hlt">mass</span> sequences occurred. These results represent an important step in identifying reliable linkages between weather and health.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.877a2038S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.877a2038S"><span>Heat <span class="hlt">exchange</span> studies on coconut oil cells as thermal energy storage for room thermal conditioning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sutjahja, I. M.; Putri, Widya A.; Fahmi, Z.; Wonorahardjo, S.; Kurnia, D.</p> <p>2017-07-01</p> <p>As reported by many thermal environment experts, room <span class="hlt">air</span> conditioning might be controlled by thermal <span class="hlt">mass</span> system. In this paper we discuss the performance of coconut oil cells as room thermal energy storage. The heat <span class="hlt">exchange</span> mechanism of coconut oil (CO) which is one of potential organic Phase Change Material (PCM) is studied based on the results of temperature measurements in the perimeter and core parts of cells. We found that the heat <span class="hlt">exchange</span> performance, i.e. heat absorption and heat release processes of CO cells are dominated by heat conduction in the sensible solid from the higher temperature perimeter part to the lower temperature core part and heat convection during the solid-liquid phase transition and sensible liquid phase. The capability of heat absorption as measured by the reduction of <span class="hlt">air</span> temperature is not influenced by CO cell size. Besides that, the application of CO as the thermal <span class="hlt">mass</span> has to be accompanied by <span class="hlt">air</span> circulation to get the cool sensation of the room’s occupants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.5784F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.5784F"><span>Short-term Rn-222 concentration changes in underground spaces with limited <span class="hlt">air</span> <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fijałkowska-Lichwa, Lidia; Przylibski, Tadeusz A.</p> <p>2010-05-01</p> <p>Authors conducted research on radon concentration in two underground structures located in the vicinity of Kletno (Sudety Mts., SW Poland), which are accessible for visitors. One of these structures is Niedźwiedzia (Bear) Cave, and the second one is the part of former uranium mine - Fluorite Adit. Both selected underground structures are characterized by almost constant temperature, changing within the range from +5 to +7° C and also constant relative humidity, close to 100%. Both these parameters testify that <span class="hlt">air</span> <span class="hlt">exchange</span> with the atmosphere is very limited. <span class="hlt">Air</span> <span class="hlt">exchange</span> is limited particularly in Niedźwiedzia Cave, which microclimate is protected i.e. by applying of locks at the entrance and exit of tourist route. The measurements were conducted between 16.05.2008. and 15.11.2009., by the use of a new Polish equipment - SRDN-3 devices with semiconductor detector. SRDN-3 device records every hour radon concentration as well as atmospheric parameters - relative humidity and temperature. At the same time authors conducted measurements of basic parameters in the open atmosphere close to Niedźwiedzia Cave. Obtained results of atmospheric parameters measurements may be used for both underground structures; because they are located within the distance of about 1 km. Atmospheric parameters were measured by the use of automatic weather station VantagePro2. On the base of conducted research authors corroborate, that the differences of radon concentration in both underground structures reach three orders of magnitude during a year. In Niedźwiedzia Cave these values are in the range from below 88 Bq/m3 (detection limit of the SRDN-3 device) up to 12 kBq/m3. Related values in Fluorite Adit are between < 88 Bq/m3 and 35 kBq/m3. It was observed also the different course of daily radon concentration changes in both structures. Additionally, authors registered that daily course of radon concentration changes differs due to season of the year. Such changes are observed in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=66495&keyword=FLOODS&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=66495&keyword=FLOODS&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>DNAPL REMOVAL MECHANISMS AND <span class="hlt">MASS</span> TRANSFER CHARACTERISTICS DURING COSOLVENT-<span class="hlt">AIR</span> FLOODING</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The concurrent injection of cosolvent and <span class="hlt">air</span>, a cosolvent-<span class="hlt">air</span> (CA) flood was recently suggested for a dense nonaqueous phase liquid (DNAPL) remediation technology. The objectives of this study were to elucidate the DNAPL removal mechanisms of the CA flood and to quantify <span class="hlt">mass</span> t...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140005795','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140005795"><span>The Use of Red Green Blue (RGB) <span class="hlt">Air</span> <span class="hlt">Mass</span> Imagery to Investigate the Role of Stratospheric <span class="hlt">Air</span> in a Non-Convective Wind Event</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berndt, Emily; Zavodsky, Bradley; Molthan, Andrew; Jedlovec, Gary</p> <p>2013-01-01</p> <p><span class="hlt">AIRS</span> ozone and model PV analysis confirm the stratospheric <span class="hlt">air</span> in RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery. Trajectories confirm winds south of the low were distinct from CCB driven winds. Cross sections connect the tropopause fold, downward motion, and high nearsurface winds. Comparison to conceptual models show Shapiro-Keyser features and sting jet characteristics were observed in a storm that impacted the U.S. East Coast. RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery can be used to identify stratospheric <span class="hlt">air</span> and regions susceptible to tropopause folding and attendant non-convective winds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002JGRD..107.8013L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002JGRD..107.8013L"><span>Trace gases and <span class="hlt">air</span> <span class="hlt">mass</span> origin at Kaashidhoo, Indian Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lobert, Jürgen M.; Harris, Joyce M.</p> <p>2002-10-01</p> <p>Carbon monoxide (CO) was measured at the Kaashidhoo Climate Observatory (KCO, Republic of Maldives) between February 1998 and March 2000 to assess the regional pollution of the remote atmosphere in the northern Indian Ocean. CO showed a distinct annual cycle with maximum daily mixing ratios of around 240 parts per billion (ppb), a seasonal difference of about 200 ppb, and high variability during the dry seasons. Detailed <span class="hlt">air</span> <span class="hlt">mass</span> trajectory analysis for 1998, 1999, and 2000 was used to identify source regions and to associate them with various levels of pollution encountered at KCO. We conclude that most significant changes in local pollution throughout the year are caused by changes in <span class="hlt">air</span> <span class="hlt">masses</span>. <span class="hlt">Air</span> at KCO generally originated from three main regions with decreasing pollution: India and southeast Asia, the Arabian Sea, and the Southern Hemisphere. We show that isentropic <span class="hlt">air</span> <span class="hlt">mass</span> trajectories can be used to predict CO pollution levels at KCO to a certain extent and vice versa. Nitrous oxide, CFC-11, CFC-12, CCI4, and SF6 were measured during the Indian Ocean Experiment (February to March 1999) to support pollution analysis and to confirm that India is the main source for heavy pollution measured at KCO. Correlations between CO and other gases and aerosol properties measured at the surface illustrate that CO may also be used as a proxy for aerosol loading and general pollution at the surface.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..12211076F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..12211076F"><span>On the Influence of <span class="hlt">Air</span> <span class="hlt">Mass</span> Origin on Low-Cloud Properties in the Southeast Atlantic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuchs, Julia; Cermak, Jan; Andersen, Hendrik; Hollmann, Rainer; Schwarz, Katharina</p> <p>2017-10-01</p> <p>This study investigates the impact of <span class="hlt">air</span> <span class="hlt">mass</span> origin and dynamics on cloud property changes in the Southeast Atlantic (SEA) during the biomass burning season. The understanding of clouds and their determinants at different scales is important for constraining the Earth's radiative budget and thus prominent in climate system research. In this study, the thermodynamically stable SEA stratocumulus cover is observed not only as the result of local environmental conditions but also as connected to large-scale meteorology by the often neglected but important role of spatial origins of <span class="hlt">air</span> <span class="hlt">masses</span> entering this region. In order to assess to what extent cloud properties are impacted by aerosol concentration, <span class="hlt">air</span> <span class="hlt">mass</span> history, and meteorology, a Hybrid Single-Particle Lagrangian Integrated Trajectory cluster analysis is conducted linking satellite observations of cloud properties (Spinning-Enhanced Visible and Infrared Imager), information on aerosol species (Monitoring Atmospheric Composition and Climate), and meteorological context (ERA-Interim reanalysis) to <span class="hlt">air</span> <span class="hlt">mass</span> clusters. It is found that a characteristic pattern of <span class="hlt">air</span> <span class="hlt">mass</span> origins connected to distinct synoptical conditions leads to marked cloud property changes in the southern part of the study area. Long-distance <span class="hlt">air</span> <span class="hlt">masses</span> are related to midlatitude weather disturbances that affect the cloud microphysics, especially in the southwestern subdomain of the study area. Changes in cloud effective radius are consistent with a boundary layer deepening and changes in lower tropospheric stability (LTS). In the southeastern subdomain cloud cover is controlled by a generally higher LTS, while <span class="hlt">air</span> <span class="hlt">mass</span> origin plays a minor role. This study leads to a better understanding of the dynamical drivers behind observed stratocumulus cloud properties in the SEA and frames potentially interesting conditions for aerosol-cloud interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E3SWC..2200002A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E3SWC..2200002A"><span>Experimental investigation and CFD simulation of multi-pipe earth-to-<span class="hlt">air</span> heat <span class="hlt">exchangers</span> (EAHEs) flow performance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amanowicz, Łukasz; Wojtkowiak, Janusz</p> <p>2017-11-01</p> <p>In this paper the experimentally obtained flow characteristics of multi-pipe earth-to-<span class="hlt">air</span> heat <span class="hlt">exchangers</span> (EAHEs) were used to validate the EAHE flow performance numerical model prepared by means of CFD software Ansys Fluent. The cut-cell meshing and the k-ɛ realizable turbulence model with default coefficients values and enhanced wall treatment was used. The total pressure losses and airflow in each pipe of multi-pipe <span class="hlt">exchangers</span> was investigated both experimentally and numerically. The results show that airflow in each pipe of multi-pipe EAHE structures is not equal. The validated numerical model can be used for a proper designing of multi-pipe EAHEs from the flow characteristics point of view. The influence of EAHEs geometrical parameters on the total pressure losses and airflow division between the <span class="hlt">exchanger</span> pipes can be also analysed. Usage of CFD for designing the EAHEs can be helpful for HVAC engineers (Heating Ventilation and <span class="hlt">Air</span> Conditioning) for optimizing the geometrical structure of multi-pipe EAHEs in order to save the energy and decrease operational costs of low-energy buildings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/111427','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/111427"><span>Analysis of two-phase flow inter-subchannel <span class="hlt">mass</span> and momentum <span class="hlt">exchanges</span> by the two-fluid model approach</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ninokata, H.; Deguchi, A.; Kawahara, A.</p> <p>1995-09-01</p> <p>A new void drift model for the subchannel analysis method is presented for the thermohydraulics calculation of two-phase flows in rod bundles where the flow model uses a two-fluid formulation for the conservation of <span class="hlt">mass</span>, momentum and energy. A void drift model is constructed based on the experimental data obtained in a geometrically simple inter-connected two circular channel test sections using <span class="hlt">air</span>-water as working fluids. The void drift force is assumed to be an origin of void drift velocity components of the two-phase cross-flow in a gap area between two adjacent rods and to overcome the momentum <span class="hlt">exchanges</span> at themore » phase interface and wall-fluid interface. This void drift force is implemented in the cross flow momentum equations. Computational results have been successfully compared to experimental data available including 3x3 rod bundle data.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA587111','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA587111"><span>Military Airlift: DOD Plans to Participate in Multi-National Program to <span class="hlt">Exchange</span> <span class="hlt">Air</span> Services with European Nations</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-10-30</p> <p><span class="hlt">Air</span> Transport, <span class="hlt">Air-to-Air</span> Refueling and Other <span class="hlt">Exchange</span> of Services ( ATARES ) program.1 ATARES is a European program through which member nations use a... ATARES is managed by the Movement Coordination Centre Europe (MCCE), a multi-national organization established in July 2007 to coordinate and optimize...of ATARES but is seeking to join the program. DOD is a member of MCCE and pays a fee for this membership; there is no additional fee to become a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJBm...61.2245E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJBm...61.2245E"><span>Relationship between <span class="hlt">air</span> <span class="hlt">mass</span> type and emergency department visits for migraine headache across the Triangle region of North Carolina</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elcik, Christopher; Fuhrmann, Christopher M.; Mercer, Andrew E.; Davis, Robert E.</p> <p>2017-12-01</p> <p>An estimated 240 million people worldwide suffer from migraines. Because migraines are often debilitating, understanding the mechanisms that trigger them is crucial for effective prevention and treatment. Synoptic <span class="hlt">air</span> <span class="hlt">mass</span> types and emergency department (ED) visits for migraine headaches were examined over a 7-year period within a major metropolitan area of North Carolina to identify potential relationships between large-scale meteorological conditions and the incidence of migraine headaches. Barometric pressure changes associated with transitional <span class="hlt">air</span> <span class="hlt">masses</span>, or changing weather patterns, were also analyzed for potential relationships. Bootstrapping analysis revealed that tropical <span class="hlt">air</span> <span class="hlt">masses</span> (moist and dry) resulted in the greatest number of migraine ED visits over the study period, whereas polar <span class="hlt">air</span> <span class="hlt">masses</span> led to fewer. Moist polar <span class="hlt">air</span> <span class="hlt">masses</span> in particular were found to correspond with the fewest number of migraine ED visits. On transitional <span class="hlt">air</span> <span class="hlt">mass</span> days, the number of migraine ED visits fell between those of tropical <span class="hlt">air</span> <span class="hlt">mass</span> days and polar <span class="hlt">air</span> <span class="hlt">mass</span> days. Transitional days characterized by pressure increases exhibited a greater number of migraine ED visits than days characterized by pressure decreases. However, no relationship was found between migraine ED visits and the magnitude of barometric pressure changes associated with transitional <span class="hlt">air</span> <span class="hlt">masses</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914729D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914729D"><span>Observing <span class="hlt">mass</span> <span class="hlt">exchange</span> with the Lofoten Basin using surface drifters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dugstad, Johannes S.; LaCasce, Joe; Koszalka, Inga M.; Fer, Ilker</p> <p>2017-04-01</p> <p>The Lofoten Basin in the Nordic Seas plays a central role in the global overturning circulation, acting as a reservoir for northward-flowing Atlantic water. Substantial heat loss occurs here, permitting the waters to become denser and eventually sink nearer the Arctic. Idealized modeling studies and theoretical arguments suggest the warm water enters the Lofoten Basin via eddy transport from the boundary current over the adjacent continental slope. But there is no observational evidence that this is the major contribution to <span class="hlt">mass</span> <span class="hlt">exchange</span> between the warm Atlantic Current and the Basin. How the basin waters exit also remains a mystery. Surface drifters offer an unique possibility to study the pathways of the boundary-basin <span class="hlt">exchange</span> of <span class="hlt">mass</span> and heat. We thereby examine trajectories of surface drifters released in the Nordic Seas in the POLEWARD and PROVOLO experiments, and supplemented by historical data from the Global Drifter Array. Contrary to the idea that the boundary current eddies are the main source, the results suggest that fluid is entering the Lofoten Basin from all sides. However, the drifters exit preferentially in the northeast corner of the basin. This asymmetry likely contributes to the extended residence times of the warm Atlantic waters in the Lofoten Basin. We consider various measures to quantify the effect, and test whether this is captured in a high resolution numerical model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27458653','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27458653"><span>Spatial Distribution and <span class="hlt">Air</span>-Water <span class="hlt">Exchange</span> of Organic Flame Retardants in the Lower Great Lakes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McDonough, Carrie A; Puggioni, Gavino; Helm, Paul A; Muir, Derek; Lohmann, Rainer</p> <p>2016-09-06</p> <p>Organic flame retardants (OFRs) such as polybrominated diphenyl ethers (PBDEs) and novel halogenated flame retardants (NHFRs) are ubiquitous, persistent, and bioaccumulative contaminants that have been used in consumer goods to slow combustion. In this study, polyethylene passive samplers (PEs) were deployed throughout the lower Great Lakes (Lake Erie and Lake Ontario) to measure OFRs in <span class="hlt">air</span> and water, calculate <span class="hlt">air</span>-water <span class="hlt">exchange</span> fluxes, and investigate spatial trends. Dissolved Σ12BDE was greatest in Lake Ontario near Toronto (18 pg/L), whereas gaseous Σ12BDE was greatest on the southern shoreline of Lake Erie (11 pg/m(3)). NHFRs were generally below detection limits. <span class="hlt">Air</span>-water <span class="hlt">exchange</span> was dominated by absorption of BDEs 47 and 99, ranging from -964 pg/m(2)/day to -30 pg/m(2)/day. Σ12BDE in <span class="hlt">air</span> and water was significantly correlated with surrounding population density, suggesting that phased-out PBDEs continued to be emitted from population centers along the Great Lakes shoreline in 2012. Correlation with dissolved Σ12BDE was strongest when considering population within 25 km while correlation with gaseous Σ12BDE was strongest when using population within 3 km to the south of each site. Bayesian kriging was used to predict dissolved Σ12BDE over the lakes, illustrating the utility of relatively highly spatially resolved measurements in identifying potential hot spots for future study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17379807','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17379807"><span>Bottom-up determination of <span class="hlt">air</span>-sea momentum <span class="hlt">exchange</span> under a major tropical cyclone.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jarosz, Ewa; Mitchell, Douglas A; Wang, David W; Teague, William J</p> <p>2007-03-23</p> <p>As a result of increasing frequency and intensity of tropical cyclones, an accurate forecasting of cyclone evolution and ocean response is becoming even more important to reduce threats to lives and property in coastal regions. To improve predictions, accurate evaluation of the <span class="hlt">air</span>-sea momentum <span class="hlt">exchange</span> is required. Using current observations recorded during a major tropical cyclone, we have estimated this momentum transfer from the ocean side of the <span class="hlt">air</span>-sea interface, and we discuss it in terms of the drag coefficient. For winds between 20 and 48 meters per second, this coefficient initially increases and peaks at winds of about 32 meters per second before decreasing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880003414','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880003414"><span>Measured performance of the heat <span class="hlt">exchanger</span> in the NASA icing research tunnel under severe icing and dry-<span class="hlt">air</span> conditions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Olsen, W.; Vanfossen, J.; Nussle, R.</p> <p>1987-01-01</p> <p>Measurements were made of the pressure drop and thermal perfomance of the unique refrigeration heat <span class="hlt">exchanger</span> in the NASA Lewis Icing Research Tunnel (IRT) under severe icing and frosting conditions and also with dry <span class="hlt">air</span>. This data will be useful to those planning to use or extend the capability of the IRT and other icing facilities (e.g., the Altitude Wind Tunnel-AWT). The IRT heat <span class="hlt">exchanger</span> and refrigeration system is able to cool <span class="hlt">air</span> passing through the test section down to at least a total temperature of -30 C (well below icing requirements), and usually up to -2 C. The system maintains a uniform temperature across the test section at all airspeeds, which is more difficult and time consuming at low airspeeds, at high temperatures, and on hot, humid days when the cooling towers are less efficient. The very small surfaces of the heat <span class="hlt">exchanger</span> prevent any icing cloud droplets from passing through it and going through the tests section again. The IRT heat <span class="hlt">exchanger</span> was originally designed not to be adversely affected by severe icing. During a worst-case icing test the heat <span class="hlt">exchanger</span> iced up enough so that the temperature uniformaity was no worse than about +/- 1 deg C. The conclusion is that the heat <span class="hlt">exchanger</span> design performs well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20085625-measurement-frost-characteristics-heat-exchanger-fins-part-test-facility-instrumentation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20085625-measurement-frost-characteristics-heat-exchanger-fins-part-test-facility-instrumentation"><span>Measurement of frost characteristics on heat <span class="hlt">exchanger</span> fins. Part 1: Test facility and instrumentation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Thomas, L.; Chen, H.; Besant, R.W.</p> <p>1999-07-01</p> <p>A special test facility was developed to characterize frost growing on heat <span class="hlt">exchanger</span> fins where the cold surfaces and the <span class="hlt">air</span> supply conditions were similar to those experienced in freezers, i.e., cold surface temperatures ranging from {minus}35 C to {minus}40 C, <span class="hlt">air</span> supply temperatures from {minus}10 C to {minus}20 C, and 80% to 100% relative humidity (RH). This test facility included a test section with removable fins to measure the frost height and <span class="hlt">mass</span> concentration. Frost height on heat <span class="hlt">exchanger</span> fins was measured using a new automated laser scanning system to measure the height of frost and its distribution onmore » selected fins. The increase in <span class="hlt">air</span> pressure loss resulting from frost growth on the fins was measured directly in the test loop. The frost <span class="hlt">mass</span> accumulation distribution was measured for each test using special pre-etched fins that could be easily subdivided and weighed. The total heat rate was measured using a heat flux meter. These frost-measuring instruments were calibrated and the uncertainty of each is stated.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25399878','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25399878"><span>Estimation of bias with the single-zone assumption in measurement of residential <span class="hlt">air</span> <span class="hlt">exchange</span> using the perfluorocarbon tracer gas method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Ryswyk, K; Wallace, L; Fugler, D; MacNeill, M; Héroux, M È; Gibson, M D; Guernsey, J R; Kindzierski, W; Wheeler, A J</p> <p>2015-12-01</p> <p>Residential <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AERs) are vital in understanding the temporal and spatial drivers of indoor <span class="hlt">air</span> quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed <span class="hlt">air</span> zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER(1z)). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER(2z)). In total, 287 daily pairs of AER(2z) and AER(1z) estimates were made from 35 homes across three cities. In 87% of the cases, AER(2z) was higher than AER(1z). Overall, the AER(1z) estimates underestimated AER(2z) by approximately 16% (IQR: 5-32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential <span class="hlt">air</span> <span class="hlt">exchange</span> using a single PFT gas, the assumption of a single well-mixed <span class="hlt">air</span> zone very likely results in an under prediction of the AER. The results of this study suggest that the long-standing assumption that a home represents a single well-mixed <span class="hlt">air</span> zone may result in a substantial negative bias in <span class="hlt">air</span> <span class="hlt">exchange</span> estimates. Indoor <span class="hlt">air</span> quality professionals should take this finding into consideration when developing study designs or making decisions related to the recommendation and installation of residential ventilation systems. © 2014 Her Majesty the Queen in Right of Canada. Indoor <span class="hlt">Air</span> published by John Wiley & Sons Ltd Reproduced with the permission of the Minister of Health Canada.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A43G2559J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A43G2559J"><span>Seasonal atmospheric deposition and <span class="hlt">air</span>-sea gaseous <span class="hlt">exchange</span> of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implication for the source-sink processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Y.; Guo, Z.</p> <p>2017-12-01</p> <p>As the home of the largest port in the world, the Yangtze River Estuary (YRE) in the East China Sea (ECS) is adjacent to the largest economic zone in China with more than 10% of Chinese population and provides one-fifth of national GDP. The YRE is under the path of contaminated East Asian continental outflow. These make the YRE unique for the pollutant biogeochemical cycling in the world. In this work, 94 pairs of <span class="hlt">air</span> samples and 20 surface seawater samples covering four seasons were collected from a remote receptor site in the YRE from March 2014 to January 2015, in order to explore the seasonal fluxes of <span class="hlt">air</span>-sea gaseous <span class="hlt">exchange</span> and atmospheric dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the <span class="hlt">air</span>-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. The gaseous PAHs were released from seawater to atmosphere during the whole year with an average of 3039 ± 2030 ng m-2 d-1. The gaseous <span class="hlt">exchange</span> of PAHs was referred as the dominant process at the <span class="hlt">air</span>-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of the total dry and wet deposition. The gaseous PAH <span class="hlt">exchange</span> flux was dominated by 3-ring PAHs, with the highest value in summer while lowest in winter, depicting a strong seasonal variation due to temperature, wind speed and <span class="hlt">air</span>-sea concentration gradient difference among seasons. Based on the simplified <span class="hlt">mass</span> balance estimation, net 9.6 tons/y of PAHs was volatilized from seawater to atmosphere with an area of approximately 20000 km2 in the YRE. Apart from Yangtze River input and ocean ship emissions in the entire year, the selective release of low molecular weight PAHs from sediments in winter due to re-suspension triggered by the East Asian winter monsoon could be another possible source for dissolved PAHs. This work suggests that the source-sink processes of PAHs at <span class="hlt">air</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930061182&hterms=uv+visible&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Duv%2Bvisible','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930061182&hterms=uv+visible&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Duv%2Bvisible"><span>On the evaluation of <span class="hlt">air</span> <span class="hlt">mass</span> factors for atmospheric near-ultraviolet and visible absorption spectroscopy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Perliski, Lori M.; Solomon, Susan</p> <p>1993-01-01</p> <p>The interpretation of UV-visible twilight absorption measurements of atmospheric chemical constituents is dependent on how well the optical path, or <span class="hlt">air</span> <span class="hlt">mass</span> factor, of light collected by the spectrometer is understood. A simple single scattering model and a Monte Carlo radiative transfer scheme have been developed to study the effects of multiple scattering, aerosol scattering, surface albedo and refraction on <span class="hlt">air</span> <span class="hlt">mass</span> factors for scattered light observations. At fairly short visible wavelengths (less than about 450 nm), stratospheric <span class="hlt">air</span> <span class="hlt">mass</span> factors are found to be relatively insensitive to multiple scattering, surface albedo and refraction, as well as aerosol scattering by background aerosols. Longer wavelengths display greater sensitivity to refraction and aerosol scattering. Tropospheric <span class="hlt">air</span> <span class="hlt">mass</span> factors are found to be highly dependent on aerosol scattering, surface albedo and, at long visible wavelengths (about 650 nm), refraction. Absorption measurements of NO2 and O4 are shown to support these conclusions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.6719V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.6719V"><span><span class="hlt">Air</span>-sea <span class="hlt">exchange</span> over Black Sea estimated from high resolution regional climate simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Velea, Liliana; Bojariu, Roxana; Cica, Roxana</p> <p>2013-04-01</p> <p>Black Sea is an important influencing factor for the climate of bordering countries, showing cyclogenetic activity (Trigo et al, 1999) and influencing Mediterranean cyclones passing over. As for other seas, standard observations of the atmosphere are limited in time and space and available observation-based estimations of <span class="hlt">air</span>-sea <span class="hlt">exchange</span> terms present quite large ranges of uncertainty. The reanalysis datasets (e.g. ERA produced by ECMWF) provide promising validation estimates of climatic characteristics against the ones in available climatic data (Schrum et al, 2001), while cannot reproduce some local features due to relatively coarse horizontal resolution. Detailed and realistic information on smaller-scale processes are foreseen to be provided by regional climate models, due to continuous improvements of physical parameterizations and numerical solutions and thus affording simulations at high spatial resolution. The aim of the study is to assess the potential of three regional climate models in reproducing known climatological characteristics of <span class="hlt">air</span>-sea <span class="hlt">exchange</span> over Black Sea, as well as to explore the added value of the model compared to the input (reanalysis) data. We employ results of long-term (1961-2000) simulations performed within ENSEMBLE project (http://ensemblesrt3.dmi.dk/) using models ETHZ-CLM, CNRM-ALADIN, METO-HadCM, for which the integration domain covers the whole area of interest. The analysis is performed for the entire basin for several variables entering the heat and water budget terms and available as direct output from the models, at seasonal and annual scale. A comparison with independent data (ERA-INTERIM) and findings from other studies (e.g. Schrum et al, 2001) is also presented. References: Schrum, C., Staneva, J., Stanev, E. and Ozsoy, E., 2001: <span class="hlt">Air</span>-sea <span class="hlt">exchange</span> in the Black Sea estimated from atmospheric analysis for the period 1979-1993, J. Marine Systems, 31, 3-19 Trigo, I. F., T. D. Davies, and G. R. Bigg (1999): Objective</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21669328','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21669328"><span>Atmospheric concentrations and <span class="hlt">air</span>-soil gas <span class="hlt">exchange</span> of polycyclic aromatic hydrocarbons (PAHs) in remote, rural village and urban areas of Beijing-Tianjin region, North China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Wentao; Simonich, Staci; Giri, Basant; Chang, Ying; Zhang, Yuguang; Jia, Yuling; Tao, Shu; Wang, Rong; Wang, Bin; Li, Wei; Cao, Jun; Lu, Xiaoxia</p> <p>2011-07-01</p> <p>Forty passive <span class="hlt">air</span> samplers were deployed to study the occurrence of gas and particulate phase PAHs in remote, rural village and urban areas of Beijing-Tianjin region, North China for four seasons (spring, summer, fall and winter) from 2007 to 2008. The influence of emissions on the spatial distribution pattern of <span class="hlt">air</span> PAH concentrations was addressed. In addition, the <span class="hlt">air</span>-soil gas <span class="hlt">exchange</span> of PAHs was studied using fugacity calculations. The median gaseous and particulate phase PAH concentrations were 222 ng/m³ and 114 ng/m³, respectively, with a median total PAH concentration of 349 ng/m³. Higher PAH concentrations were measured in winter than in other seasons. <span class="hlt">Air</span> PAH concentrations measured at the rural villages and urban sites in the northern mountain region were significantly lower than those measured at sites in the southern plain during all seasons. However, there was no significant difference in PAH concentrations between the rural villages and urban sites in the northern and southern areas. This urban-rural PAH distribution pattern was related to the location of PAH emission sources and the population distribution. The location of PAH emission sources explained 56%-77% of the spatial variation in ambient <span class="hlt">air</span> PAH concentrations. The annual median <span class="hlt">air</span>-soil gas <span class="hlt">exchange</span> flux of PAHs was 42.2 ng/m²/day from soil to <span class="hlt">air</span>. Among the 15 PAHs measured, acenaphthylene (ACY) and acenaphthene (ACE) contributed to more than half of the total <span class="hlt">exchange</span> flux. Furthermore, the <span class="hlt">air</span>-soil gas <span class="hlt">exchange</span> fluxes of PAHs at the urban sites were higher than those at the remote and rural sites. In summer, more gaseous PAHs volatilized from soil to <span class="hlt">air</span> because of higher temperatures and increased rainfall. However, in winter, more gaseous PAHs deposited from <span class="hlt">air</span> to soil due to higher PAH emissions and lower temperatures. The soil TOC concentration had no significant influence on the <span class="hlt">air</span>-soil gas <span class="hlt">exchange</span> of PAHs. Copyright © 2011 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1214990','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1214990"><span><span class="hlt">Air</span>-Cooled Heat <span class="hlt">Exchanger</span> for High-Temperature Power Electronics: Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Waye, S. K.; Lustbader, J.; Musselman, M.</p> <p>2015-05-06</p> <p>This work demonstrates a direct <span class="hlt">air</span>-cooled heat <span class="hlt">exchanger</span> strategy for high-temperature power electronic devices with an application specific to automotive traction drive inverters. We present experimental heat dissipation and system pressure curves versus flow rate for baseline and optimized sub-module assemblies containing two ceramic resistance heaters that provide device heat fluxes. The maximum allowable junction temperature was set to 175 deg.C. Results were extrapolated to the inverter scale and combined with balance-of-inverter components to estimate inverter power density and specific power. The results exceeded the goal of 12 kW/L and 12 kW/kg for power density and specific power, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24274333','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24274333"><span>Hydrogen <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry of functional membrane-bound chemotaxis receptor complexes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Koshy, Seena S; Eyles, Stephen J; Weis, Robert M; Thompson, Lynmarie K</p> <p>2013-12-10</p> <p>The transmembrane signaling mechanism of bacterial chemotaxis receptors is thought to involve changes in receptor conformation and dynamics. The receptors function in ternary complexes with two other proteins, CheA and CheW, that form extended membrane-bound arrays. Previous studies have shown that attractant binding induces a small (∼2 Å) piston displacement of one helix of the periplasmic and transmembrane domains toward the cytoplasm, but it is not clear how this signal propagates through the cytoplasmic domain to control the kinase activity of the CheA bound at the membrane-distal tip, nearly 200 Å away. The cytoplasmic domain has been shown to be highly dynamic, which raises the question of how a small piston motion could propagate through a dynamic domain to control CheA kinase activity. To address this, we have developed a method for measuring dynamics of the receptor cytoplasmic fragment (CF) in functional complexes with CheA and CheW. Hydrogen-deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) measurements of global <span class="hlt">exchange</span> of the CF demonstrate that the CF exhibits significantly slower <span class="hlt">exchange</span> in functional complexes than in solution. Because the <span class="hlt">exchange</span> rates in functional complexes are comparable to those of other proteins with similar structures, the CF appears to be a well-structured protein within these complexes, which is compatible with its role in propagating a signal that appears to be a tiny conformational change in the periplasmic and transmembrane domains of the receptor. We also demonstrate the feasibility of this protocol for local <span class="hlt">exchange</span> measurements by incorporating a pepsin digest step to produce peptides with 87% sequence coverage and only 20% back <span class="hlt">exchange</span>. This method extends HDX-MS to membrane-bound functional complexes without detergents that may perturb the stability or structure of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3922707','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3922707"><span>Hydrogen <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry of Functional Membrane-bound Chemotaxis Receptor Complexes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Koshy, Seena S.; Eyles, Stephen J.; Weis, Robert M.; Thompson, Lynmarie K.</p> <p>2014-01-01</p> <p>The transmembrane signaling mechanism of bacterial chemotaxis receptors is thought to involve changes in receptor conformation and dynamics. The receptors function in ternary complexes with two other proteins, CheA and CheW, that form extended membrane-bound arrays. Previous studies have shown that attractant binding induces a small (~2 Å) piston displacement of one helix of the periplasmic and transmembrane domains towards the cytoplasm, but it is not clear how this signal propagates through the cytoplasmic domain to control the kinase activity of the CheA bound at the membrane-distal tip, nearly 200 Å away. The cytoplasmic domain has been shown to be highly dynamic, which raises the question of how a small piston motion could propagate through a dynamic domain to control CheA kinase activity. To address this, we have developed a method for measuring dynamics of the receptor cytoplasmic fragment (CF) in functional complexes with CheA and CheW. Hydrogen <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) measurements of global <span class="hlt">exchange</span> of CF demonstrate that CF exhibits significantly slower <span class="hlt">exchange</span> in functional complexes than in solution. Since the <span class="hlt">exchange</span> rates in functional complexes are comparable to that of other proteins of similar structure, the CF appears to be a well-structured protein within these complexes, which is compatible with its role in propagating a signal that appears to be a tiny conformational change in the periplasmic and transmembrane domains of the receptor. We also demonstrate the feasibility of this protocol for local <span class="hlt">exchange</span> measurements, by incorporating a pepsin digest step to produce peptides with 87% sequence coverage and only 20% back <span class="hlt">exchange</span>. This method extends HDX-MS to membrane-bound functional complexes without detergents that may perturb the stability or structure of the system. PMID:24274333</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4490136','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4490136"><span><span class="hlt">Air</span> <span class="hlt">exchange</span> rates and migration of VOCs in basements and residences</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Du, Liuliu; Batterman, Stuart; Godwin, Christopher; Rowe, Zachary; Chin, Jo-Yu</p> <p>2015-01-01</p> <p>Basements can influence indoor <span class="hlt">air</span> quality by affecting <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AERs) and by the presence of emission sources of volatile organic compounds (VOCs) and other pollutants. We characterized VOC levels, AERs and interzonal flows between basements and occupied spaces in 74 residences in Detroit, Michigan. Flows were measured using a steady-state multi-tracer system, and 7-day VOC measurements were collected using passive samplers in both living areas and basements. A walkthrough survey/inspection was conducted in each residence. AERs in residences and basements averaged 0.51 and 1.52 h−1, respectively, and had strong and opposite seasonal trends, e.g., AERs were highest in residences during the summer, and highest in basements during the winter. <span class="hlt">Air</span> flows from basements to occupied spaces also varied seasonally. VOC concentration distributions were right-skewed, e.g., 90th percentile benzene, toluene, naphthalene and limonene concentrations were 4.0, 19.1, 20.3 and 51.0 μg m−3, respectively; maximum concentrations were 54, 888, 1117 and 134 μg m−3. Identified VOC sources in basements included solvents, household cleaners, <span class="hlt">air</span> fresheners, smoking, and gasoline-powered equipment. The number and type of potential VOC sources found in basements are significant and problematic, and may warrant advisories regarding the storage and use of potentially strong VOCs sources in basements. PMID:25601281</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AtmEn.178..255G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AtmEn.178..255G"><span>Particle growth in an isoprene-rich forest: Influences of urban, wildfire, and biogenic <span class="hlt">air</span> <span class="hlt">masses</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gunsch, Matthew J.; Schmidt, Stephanie A.; Gardner, Daniel J.; Bondy, Amy L.; May, Nathaniel W.; Bertman, Steven B.; Pratt, Kerri A.; Ault, Andrew P.</p> <p>2018-04-01</p> <p>Growth of freshly nucleated particles is an important source of cloud condensation nuclei (CCN) and has been studied within a variety of environments around the world. However, there remains uncertainty regarding the sources of the precursor gases leading to particle growth, particularly in isoprene-rich forests. In this study, particle growth events were observed from the 14 total events (31% of days) during summer measurements (June 24 - August 2, 2014) at the Program for Research on Oxidants PHotochemistry, Emissions, and Transport (PROPHET) tower within the forested University of Michigan Biological Station located in northern Michigan. Growth events were observed within long-range transported <span class="hlt">air</span> <span class="hlt">masses</span> from urban areas, <span class="hlt">air</span> <span class="hlt">masses</span> impacted by wildfires, as well as stagnant, forested/regional <span class="hlt">air</span> <span class="hlt">masses</span>. Growth events observed during urban-influenced <span class="hlt">air</span> <span class="hlt">masses</span> were prevalent, with presumably high oxidant levels, and began midday during periods of high solar radiation. This suggests that increased oxidation of biogenic volatile organic compounds (BVOCs) likely contributed to the highest observed particle growth in this study (8 ± 2 nm h-1). Growth events during wildfire-influenced <span class="hlt">air</span> <span class="hlt">masses</span> were observed primarily at night and had slower growth rates (3 ± 1 nm h-1). These events were likely influenced by increased SO2, O3, and NO2 transported within the smoke plumes, suggesting a role of NO3 oxidation in the production of semi-volatile compounds. Forested/regional <span class="hlt">air</span> <span class="hlt">mass</span> growth events likely occurred due to the oxidation of regionally emitted BVOCs, including isoprene, monoterpenes, and sesquiterpenes, which facilitated multiday growth events also with slower rates (3 ± 2 nm h-1). Intense sulfur, carbon, and oxygen signals in individual particles down to 20 nm, analyzed by transmission electron microscopy with energy dispersive X-ray spectroscopy (TEM-EDX), suggest that H2SO4 and secondary organic aerosol contributed to particle growth. Overall, aerosol</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-LRC-1957-B701_P-05383.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-LRC-1957-B701_P-05383.html"><span>Hot-<span class="hlt">Air</span> Jets/Ceramic Heat <span class="hlt">Exchangers</span>/ Materials for Nose Cones and Reentry Vehicles</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1957-09-07</p> <p>L57-5383 Hot-<span class="hlt">air</span> jets employing ceramic heat <span class="hlt">exchangers</span> played an important role at Langley in the study of materials for ballistic missile nose cones and re-entry vehicles. Here a model is being tested in one of theses jets at 4000 degrees Fahrenheit in 1957. Photograph published in Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917-1958 by James R. Hansen. Page 477.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15683168','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15683168"><span><span class="hlt">Air</span>-water gas <span class="hlt">exchange</span> of chlorinated pesticides in four lakes spanning a 1,205 meter elevation range in the Canadian Rocky Mountains.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wilkinson, Andrew C; Kimpe, Lynda E; Blais, Jules M</p> <p>2005-01-01</p> <p>Concentrations of selected persistent organic pollutants (POPs) in <span class="hlt">air</span> and water were measured from four lakes that transect the Canadian Rocky Mountains. These data were used in combination with wind velocity and temperature-adjusted Henry's law constants to estimate the direction and magnitude of chemical <span class="hlt">exchange</span> across the <span class="hlt">air</span>-water interface of these lakes. Bow Lake (1,975 m above sea level [masl]) was studied during the summers of 1998 through 2000; Donald (770 masl) was studied during the summer of 1999; Dixon Dam Lake (946 masl) and Kananaskis Lake (1,667 masl) were studied during the summer of 2000. Hexachlorobenzene (HCB) and dieldrin volatilized from Bow Lake in spring and summer of 1998 to 2000 at a rate of 0.92 +/-1.1 and 0.55+/-0.37 ng m(-2) d(-1), respectively. The alpha-endosulfan deposited to Bow Lake at a rate of 3.4+/-2.2 ng m(-2) d(-1). Direction of gas <span class="hlt">exchange</span> for gamma-hexachlorocyclohexane (gamma-HCH) changed from net deposition in 1998 to net volatilization in 1999, partly because of a surge in y-HCH concentrations in the water at Bow Lake in 1999. Average gamma-HCH concentrations in <span class="hlt">air</span> declined steadily over the three-year period, from 0.021 ng m(-3) in 1998, to 0.0023 ng m(-3) in 2000, and to volatilization in 1999 and 2000. Neither the concentrations of organochlorine compounds (OCs) in <span class="hlt">air</span> and water, nor the direction and rate of <span class="hlt">air</span>-water gas <span class="hlt">exchange</span> correlate with temperature or elevation. In general, losses of pesticides by outflow were greater than the amount <span class="hlt">exchanged</span> across the <span class="hlt">air</span>-water interface in these lakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26930305','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26930305"><span>Trends and sources vs <span class="hlt">air</span> <span class="hlt">mass</span> origins in a major city in South-western Europe: Implications for <span class="hlt">air</span> quality management.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernández-Camacho, R; de la Rosa, J D; Sánchez de la Campa, A M</p> <p>2016-05-15</p> <p>This study presents a 17-years <span class="hlt">air</span> quality database comprised of different parameters corresponding to the largest city in the south of Spain (Seville) where atmospheric pollution is frequently attributed to traffic emissions and is directly affected by Saharan dust outbreaks. We identify the PM10 contributions from both natural and anthropogenic sources in this area associated to different <span class="hlt">air</span> <span class="hlt">mass</span> origins. Hourly, daily and seasonal variation of PM10 and gaseous pollutant concentrations (CO, NO2 and SO2), all of them showing negative trends during the study period, point to the traffic as one of the main sources of <span class="hlt">air</span> pollution in Seville. Mineral dust, secondary inorganic compounds (SIC) and trace elements showed higher concentrations under North African (NAF) <span class="hlt">air</span> <span class="hlt">mass</span> origins than under Atlantic. We observe a decreasing trend in all chemical components of PM10 under both types of <span class="hlt">air</span> <span class="hlt">masses</span>, NAF and Atlantic. Principal component analysis using more frequent <span class="hlt">air</span> <span class="hlt">masses</span> in the area allows the identification of five PM10 sources: crustal, regional, marine, traffic and industrial. Natural sources play a more relevant role during NAF events (20.6 μg · m(-3)) than in Atlantic episodes (13.8 μg · m(-3)). The contribution of the anthropogenic sources under NAF doubles the one under Atlantic conditions (33.6 μg · m(-3) and 15.8 μg · m(-3), respectively). During Saharan dust outbreaks the frequent accumulation of local anthropogenic pollutants in the lower atmosphere results in poor <span class="hlt">air</span> quality and an increased risk of mortality. The results are relevant when analysing the impact of anthropogenic emissions on the exposed population in large cities. The increase in potentially toxic elements during Saharan dust outbreaks should also be taken into account when discounting the number of exceedances attributable to non-anthropogenic or natural origins. Copyright © 2016 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14667723','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14667723"><span>Current issues and uncertainties in the measurement and modelling of <span class="hlt">air</span>-vegetation <span class="hlt">exchange</span> and within-plant processing of POPs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barber, Jonathan L; Thomas, Gareth O; Kerstiens, Gerhard; Jones, Kevin C</p> <p>2004-01-01</p> <p><span class="hlt">Air</span>-vegetation <span class="hlt">exchange</span> of POPs is an important process controlling the entry of POPs into terrestrial food chains, and may also have a significant effect on the global movement of these compounds. Many factors affect the <span class="hlt">air</span>-vegetation transfer including: the physicochemical properties of the compounds of interest; environmental factors such as temperature, wind speed, humidity and light conditions; and plant characteristics such as functional type, leaf surface area, cuticular structure, and leaf longevity. The purpose of this review is to quantify the effects these differences might have on <span class="hlt">air</span>/plant <span class="hlt">exchange</span> of POPs, and to point out the major gaps in the knowledge of this subject that require further research. Uptake mechanisms are complicated, with the role of each factor in controlling partitioning, fate and behaviour process still not fully understood. Consequently, current models of <span class="hlt">air</span>-vegetation <span class="hlt">exchange</span> do not incorporate variability in these factors, with the exception of temperature. These models instead rely on using average values for a number of environmental factors (e.g. plant lipid content, surface area), ignoring the large variations in these values. The available models suggest that boundary layer conductance is of key importance in the uptake of POPs, although large uncertainties in the cuticular pathway prevents confirmation of this with any degree of certainty, and experimental data seems to show plant-side resistance to be important. Models are usually based on the assumption that POP uptake occurs through the lipophilic cuticle which covers aerial surfaces of plants. However, some authors have recently attached greater importance to the stomatal route of entry into the leaf for gas phase compounds. There is a need for greater mechanistic understanding of <span class="hlt">air</span>-plant <span class="hlt">exchange</span> and the 'scaling' of factors affecting it. The review also suggests a number of key variables that researchers should measure in their experiments to allow comparisons</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110014867','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110014867"><span>Fault-Tolerant Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Izenson, Michael G.; Crowley, Christopher J.</p> <p>2005-01-01</p> <p>A compact, lightweight heat <span class="hlt">exchanger</span> has been designed to be fault-tolerant in the sense that a single-point leak would not cause mixing of heat-transfer fluids. This particular heat <span class="hlt">exchanger</span> is intended to be part of the temperature-regulation system for habitable modules of the International Space Station and to function with water and ammonia as the heat-transfer fluids. The basic fault-tolerant design is adaptable to other heat-transfer fluids and heat <span class="hlt">exchangers</span> for applications in which mixing of heat-transfer fluids would pose toxic, explosive, or other hazards: Examples could include fuel/<span class="hlt">air</span> heat <span class="hlt">exchangers</span> for thermal management on aircraft, process heat <span class="hlt">exchangers</span> in the cryogenic industry, and heat <span class="hlt">exchangers</span> used in chemical processing. The reason this heat <span class="hlt">exchanger</span> can tolerate a single-point leak is that the heat-transfer fluids are everywhere separated by a vented volume and at least two seals. The combination of fault tolerance, compactness, and light weight is implemented in a unique heat-<span class="hlt">exchanger</span> core configuration: Each fluid passage is entirely surrounded by a vented region bridged by solid structures through which heat is conducted between the fluids. Precise, proprietary fabrication techniques make it possible to manufacture the vented regions and heat-conducting structures with very small dimensions to obtain a very large coefficient of heat transfer between the two fluids. A large heat-transfer coefficient favors compact design by making it possible to use a relatively small core for a given heat-transfer rate. Calculations and experiments have shown that in most respects, the fault-tolerant heat <span class="hlt">exchanger</span> can be expected to equal or exceed the performance of the non-fault-tolerant heat <span class="hlt">exchanger</span> that it is intended to supplant (see table). The only significant disadvantages are a slight weight penalty and a small decrease in the <span class="hlt">mass</span>-specific heat transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2757243','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2757243"><span>Actin Isoform-specific Conformational Differences Observed with Hydrogen/Deuterium <span class="hlt">Exchange</span> and <span class="hlt">Mass</span> Spectrometry*</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stokasimov, Ema; Rubenstein, Peter A.</p> <p>2009-01-01</p> <p>Actin can exist in multiple conformations necessary for normal function. Actin isoforms, although highly conserved in sequence, exhibit different biochemical properties and cellular roles. We used amide proton hydrogen/deuterium (HD) <span class="hlt">exchange</span> detected by <span class="hlt">mass</span> spectrometry to analyze conformational differences between Saccharomyces cerevisiae and muscle actins in the G and F forms to gain insight into these differences. We also utilized HD <span class="hlt">exchange</span> to study interdomain and allosteric communication in yeast-muscle hybrid actins to better understand the conformational dynamics of actin. Areas showing differences in HD <span class="hlt">exchange</span> between G- and F-actins are areas of intermonomer contacts, consistent with the current filament models. Our results showed greater <span class="hlt">exchange</span> for yeast G-actin compared with muscle actin in the barbed end pivot region and areas in subdomains 1 and 2 and for F-actin in monomer-monomer contact areas. These results suggest greater flexibility of the yeast actin monomer and filament compared with muscle actin. For hybrid G-actins, the muscle-like and yeastlike parts of the molecule generally showed <span class="hlt">exchange</span> characteristics resembling their parent actins. A few exceptions were a peptide on top of subdomain 2 and the pivot region between subdomains 1 and 3 with muscle actin-like <span class="hlt">exchange</span> characteristics although the areas were yeastlike. These results demonstrate that there is cross-talk between subdomains 1 and 2 and the large and small domains. Hybrid F-actin data showing greater <span class="hlt">exchange</span> compared with both yeast and muscle actins are consistent with mismatched yeast-muscle interfaces resulting in decreased stability of the hybrid filament contacts. PMID:19605362</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..122.1203W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..122.1203W"><span>Low-CCN concentration <span class="hlt">air</span> <span class="hlt">masses</span> over the eastern North Atlantic: Seasonality, meteorology, and drivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wood, Robert; Stemmler, Jayson D.; Rémillard, Jasmine; Jefferson, Anne</p> <p>2017-01-01</p> <p>A 20 month cloud condensation nucleus concentration (NCCN) data set from Graciosa Island (39°N, 28°W) in the remote North Atlantic is used to characterize <span class="hlt">air</span> <span class="hlt">masses</span> with low cloud condensation nuclei (CCN) concentrations. Low-CCN events are defined as 6 h periods with mean NCCN<20 cm-3 (0.1% supersaturation). A total of 47 low-CCN events are identified. Surface, satellite, and reanalysis data are used to explore the meteorological and cloud context for low-CCN <span class="hlt">air</span> <span class="hlt">masses</span>. Low-CCN events occur in all seasons, but their frequency was 3 times higher in December-May than during June-November. Composites show that many of the low-CCN events had a common meteorological basis that involves southerly low-level flow and rather low wind speeds at Graciosa. Anomalously low pressure is situated to the west of Graciosa during these events, but back trajectories and lagged SLP composites indicate that low-CCN <span class="hlt">air</span> <span class="hlt">masses</span> often originate as cold <span class="hlt">air</span> outbreaks to the north and west of Graciosa. Low-CCN events were associated with low cloud droplet concentrations (Nd) at Graciosa, but liquid water path (LWP) during low-CCN events was not systematically different from that at other times. Satellite Nd and LWP estimates from MODIS collocated with Lagrangian back trajectories show systematically lower Nd and higher LWP several days prior to arrival at Graciosa, consistent with the hypothesis that observed low-CCN <span class="hlt">air</span> <span class="hlt">masses</span> are often formed by coalescence scavenging in thick warm clouds, often in cold <span class="hlt">air</span> outbreaks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HMT....52.2213B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HMT....52.2213B"><span>Influence of drying <span class="hlt">air</span> parameters on <span class="hlt">mass</span> transfer characteristics of apple slices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beigi, Mohsen</p> <p>2016-10-01</p> <p>To efficiently design both new drying process and equipment and/or to improve the existing systems, accurate values of <span class="hlt">mass</span> transfer characteristics are necessary. The present study aimed to investigate the influence of drying <span class="hlt">air</span> parameters (i.e. temperature, velocity and relative humidity) on effective diffusivity and convective <span class="hlt">mass</span> transfer coefficient of apple slices. The Dincer and Dost model was used to determine the <span class="hlt">mass</span> transfer characteristics. The obtained Biot number indicated that the moisture transfer in the apple slices was controlled by both internal and external resistance. The effective diffusivity and <span class="hlt">mass</span> transfer coefficient values obtained to be in the ranges of 7.13 × 10-11-7.66 × 10-10 and 1.46 × 10-7-3.39 × 10-7 m s-1, respectively and the both of them increased with increasing drying <span class="hlt">air</span> temperature and velocity, and decreasing relative humidity. The validation of the model showed that the model predicted the experimental drying curves of the samples with a good accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AtmEn.147..200O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AtmEn.147..200O"><span>Determination of temperature dependent Henry's law constants of polychlorinated naphthalenes: Application to <span class="hlt">air</span>-sea <span class="hlt">exchange</span> in Izmir Bay, Turkey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Odabasi, Mustafa; Adali, Mutlu</p> <p>2016-12-01</p> <p>The Henry's law constant (H) is a crucial variable to investigate the <span class="hlt">air</span>-water <span class="hlt">exchange</span> of persistent organic pollutants. H values for 32 polychlorinated naphthalene (PCN) congeners were measured using an inert gas-stripping technique at five temperatures ranging between 5 and 35 °C. H values in deionized water (at 25 °C) varied between 0.28 ± 0.08 Pa m3 mol-1 (PCN-73) and 18.01 ± 0.69 Pa m3 mol-1 (PCN-42). The agreement between the measured and estimated H values from the octanol-water and octanol-<span class="hlt">air</span> partition coefficients was good (measured/estimated ratio = 1.00 ± 0.41, average ± SD). The calculated phase change enthalpies (ΔHH) were within the interval previously determined for other several semivolatile organic compounds (42.0-106.4 kJ mol-1). Measured H values, paired atmospheric and aqueous concentrations and meteorological variables were also used to reveal the level and direction of <span class="hlt">air</span>-sea <span class="hlt">exchange</span> fluxes of PCNs at the coast of Izmir Bay, Turkey. The net PCN <span class="hlt">air</span>-sea <span class="hlt">exchange</span> flux varied from -0.55 (volatilization, PCN-24/14) to 2.05 (deposition, PCN-23) ng m-2 day-1. PCN-19, PCN-24/14, PCN-42, and PCN-33/34/37 were mainly volatilized from seawater while the remaining congeners were mainly deposited. The overall number of the cases showing deposition was higher (67.9%) compared to volatilization (21.4%) and near equilibrium (10.7%).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22571272','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22571272"><span>Improved protein hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry platform with fully automated data processing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Zhongqi; Zhang, Aming; Xiao, Gang</p> <p>2012-06-05</p> <p>Protein hydrogen/deuterium <span class="hlt">exchange</span> (HDX) followed by protease digestion and <span class="hlt">mass</span> spectrometric (MS) analysis is accepted as a standard method for studying protein conformation and conformational dynamics. In this article, an improved HDX MS platform with fully automated data processing is described. The platform significantly reduces systematic and random errors in the measurement by introducing two types of corrections in HDX data analysis. First, a mixture of short peptides with fast HDX rates is introduced as internal standards to adjust the variations in the extent of back <span class="hlt">exchange</span> from run to run. Second, a designed unique peptide (PPPI) with slow intrinsic HDX rate is employed as another internal standard to reflect the possible differences in protein intrinsic HDX rates when protein conformations at different solution conditions are compared. HDX data processing is achieved with a comprehensive HDX model to simulate the deuterium labeling and back <span class="hlt">exchange</span> process. The HDX model is implemented into the in-house developed software <span class="hlt">Mass</span>Analyzer and enables fully unattended analysis of the entire protein HDX MS data set starting from ion detection and peptide identification to final processed HDX output, typically within 1 day. The final output of the automated data processing is a set (or the average) of the most possible protection factors for each backbone amide hydrogen. The utility of the HDX MS platform is demonstrated by exploring the conformational transition of a monoclonal antibody by increasing concentrations of guanidine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1965U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1965U"><span>CO2 and O2 Gas <span class="hlt">Exchange</span> in an Experimental Model of the Btlss with Plant Wastes and Human Wastes Included in the <span class="hlt">Mass</span> <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ushakova, Sofya; Tikhomirov, Alexander A.; Velichko, Vladimir; Tikhomirova, Natalia; Trifonov, Sergey V.</p> <p>2016-07-01</p> <p><span class="hlt">Mass</span> <span class="hlt">exchange</span> processes in the new experimental model of the biotechnical life support system (BTLSS) constructed at the Institute of Biophysics SB RAS have a higher degree of closure than in the previous BTLSS, and, thus, the technologies employed in the new system are more complex. Therefore, before closing the loops of <span class="hlt">mass</span> <span class="hlt">exchange</span> processes for several months, the new model of the BTLSS was run to match the technologies employed to cultivate plants and the methods used to involve inedible plant parts and human wastes into the <span class="hlt">mass</span> <span class="hlt">exchange</span> with the CO2 absorption rate and the amount of the resulting O2. The plant compartment included vegetables grown on the soil-like substrate (SLS) (chufa, beet, carrot, radish, and lettuce), plants hydroponically grown on expanded clay aggregate (wheat, soybean, watercress), and plants grown in aquaculture (common glasswort and watercress). Nutrient solutions for hydroponically grown plants were prepared by using products of physicochemical mineralization of human wastes. Growing the plants in aquaculture enabled maintaining NaCl concentration in the irrigation solution for hydroponically grown plants at a level safe for the plants. Inedible plant biomass was added to the SLS. Three cycles of closing the system were run, which lasted 7, 7, and 10 days. The comparison of the amount of CO2 fed into the system over 24 h (simulating human respiration) and the amount of CO2 daily exhaled by a 70-kg middle-aged human showed that between 1% and 4% of the daily emissions of CO2 were assimilated in the system, and about 3% of the average human daily O2 requirement accumulated in the system. Plant productivity was between 4 and 4.7% of the human daily vegetable requirement, or between 3 and 3.5% of the total human daily food requirement. Thus, testing of the BTLSS showed a match between the technologies employed to arrange <span class="hlt">mass</span> <span class="hlt">exchange</span> processes. This study was supported by the grant of the Russian Science Foundation (Project No. 14-14-00599).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15279352','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15279352"><span>Microbial <span class="hlt">air</span> quality in <span class="hlt">mass</span> transport buses and work-related illness among bus drivers of Bangkok <span class="hlt">Mass</span> Transit Authority.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luksamijarulkul, Pipat; Sundhiyodhin, Viboonsri; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan</p> <p>2004-06-01</p> <p>The <span class="hlt">air</span> quality in <span class="hlt">mass</span> transport buses, especially <span class="hlt">air</span>-conditioned buses may affect bus drivers who work full time. Bus numbers 16, 63, 67 and 166 of the Seventh Bus Zone of Bangkok <span class="hlt">Mass</span> Transit Authority were randomly selected to investigate for microbial <span class="hlt">air</span> quality. Nine <span class="hlt">air</span>-conditioned buses and 2-4 open-<span class="hlt">air</span> buses for each number of the bus (36 <span class="hlt">air</span>-conditioned buses and 12 open-<span class="hlt">air</span> buses) were included. Five points of in-bus <span class="hlt">air</span> samples in each studied bus were collected by using the Millipore A ir Tester Totally, 180 and 60 <span class="hlt">air</span> samples collected from <span class="hlt">air</span>-conditioned buses and open-<span class="hlt">air</span> buses were cultured for bacterial and fungal counts. The bus drivers who drove the studied buses were interviewed towards histories of work-related illness while working. The results revealed that the mean +/- SD of bacterial counts in the studied open-<span class="hlt">air</span> buses ranged from 358.50 +/- 146.66 CFU/m3 to 506 +/- 137.62 CFU/m3; bus number 16 had the highest level. As well as the mean +/- SD of fungal counts which ranged from 93.33 +/- 44.83 CFU/m3 to 302 +/- 294.65 CFU/m3; bus number 166 had the highest level. Whereas, the mean +/- SD of bacterial counts in the studied <span class="hlt">air</span>-conditioned buses ranged from 115.24 +/- 136.01 CFU/m3 to 244.69 +/- 234.85 CFU/m3; bus numbers 16 and 67 had the highest level. As well as the mean +/- SD of fungal counts which rangedfrom 18.84 +/- 39.42 CFU/m3 to 96.13 +/- 234.76 CFU/m3; bus number 166 had the highest level. When 180 and 60 studied <span class="hlt">air</span> samples were analyzed in detail, it was found that 33.33% of the <span class="hlt">air</span> samples from open-<span class="hlt">air</span> buses and 6.11% of <span class="hlt">air</span> samples from <span class="hlt">air</span>-conditioned buses had a high level of bacterial counts (> 500 CFU/m3) while 6.67% of <span class="hlt">air</span> samples from open-<span class="hlt">air</span> buses and 2.78% of <span class="hlt">air</span> samples from <span class="hlt">air</span>-conditioned buses had a high level of fungal counts (> 500 CFU/m3). Data from the history of work-related illnesses among the studied bus drivers showed that 91.67% of open-<span class="hlt">air</span> bus drivers and 57.28% of <span class="hlt">air</span>-conditioned bus drivers had</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25386953','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25386953"><span>Modeling spatial and temporal variability of residential <span class="hlt">air</span> <span class="hlt">exchange</span> rates for the Near-Road Exposures and Effects of Urban <span class="hlt">Air</span> Pollutants Study (NEXUS).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Breen, Michael S; Burke, Janet M; Batterman, Stuart A; Vette, Alan F; Godwin, Christopher; Croghan, Carry W; Schultz, Bradley D; Long, Thomas C</p> <p>2014-11-07</p> <p><span class="hlt">Air</span> pollution health studies often use outdoor concentrations as exposure surrogates. Failure to account for variability of residential infiltration of outdoor pollutants can induce exposure errors and lead to bias and incorrect confidence intervals in health effect estimates. The residential <span class="hlt">air</span> <span class="hlt">exchange</span> rate (AER), which is the rate of <span class="hlt">exchange</span> of indoor <span class="hlt">air</span> with outdoor <span class="hlt">air</span>, is an important determinant for house-to-house (spatial) and temporal variations of <span class="hlt">air</span> pollution infiltration. Our goal was to evaluate and apply mechanistic models to predict AERs for 213 homes in the Near-Road Exposures and Effects of Urban <span class="hlt">Air</span> Pollutants Study (NEXUS), a cohort study of traffic-related <span class="hlt">air</span> pollution exposures and respiratory effects in asthmatic children living near major roads in Detroit, Michigan. We used a previously developed model (LBL), which predicts AER from meteorology and questionnaire data on building characteristics related to <span class="hlt">air</span> leakage, and an extended version of this model (LBLX) that includes natural ventilation from open windows. As a critical and novel aspect of our AER modeling approach, we performed a cross validation, which included both parameter estimation (i.e., model calibration) and model evaluation, based on daily AER measurements from a subset of 24 study homes on five consecutive days during two seasons. The measured AER varied between 0.09 and 3.48 h(-1) with a median of 0.64 h(-1). For the individual model-predicted and measured AER, the median absolute difference was 29% (0.19 h‑1) for both the LBL and LBLX models. The LBL and LBLX models predicted 59% and 61% of the variance in the AER, respectively. Daily AER predictions for all 213 homes during the three year study (2010-2012) showed considerable house-to-house variations from building leakage differences, and temporal variations from outdoor temperature and wind speed fluctuations. Using this novel approach, NEXUS will be one of the first epidemiology studies to apply calibrated and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14503509','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14503509"><span><span class="hlt">Mass</span> <span class="hlt">exchange</span> in an experimental new-generation life support system model based on biological regeneration of environment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tikhomirov, A A; Ushakova, S A; Manukovsky, N S; Lisovsky, G M; Kudenko, Yu A; Kovalev, V S; Gubanov, V G; Barkhatov, Yu V; Gribovskaya, I V; Zolotukhin, I G; Gros, J B; Lasseur, Ch</p> <p>2003-01-01</p> <p>An experimental model of a biological life support system was used to evaluate qualitative and quantitative parameters of the internal <span class="hlt">mass</span> <span class="hlt">exchange</span>. The photosynthesizing unit included the higher plant component (wheat and radish), and the heterotrophic unit consisted of a soil-like substrate, California worms, mushrooms and microbial microflora. The gas <span class="hlt">mass</span> <span class="hlt">exchange</span> involved evolution of oxygen by the photosynthesizing component and its uptake by the heterotroph component along with the formation and maintaining of the SLS structure, growth of mushrooms and California worms, human respiration, and some other processes. Human presence in the system in the form of "virtual human" that at regular intervals took part in the respirative gas <span class="hlt">exchange</span> during the experiment. Experimental data demonstrated good oxygen/carbon dioxide balance, and the closure of the cycles of these gases was almost complete. The water cycle was nearly 100% closed. The main components in the water <span class="hlt">mass</span> <span class="hlt">exchange</span> were transpiration water and the watering solution with mineral elements. Human consumption of the edible plant biomass (grains and roots) was simulated by processing these products by a unique physicochemical method of oxidizing them to inorganic mineral compounds, which were then returned into the system and fully assimilated by the plants. The oxidation was achieved by "wet combustion" of organic biomass, using hydrogen peroxide following a special procedure, which does not require high temperature and pressure. Hydrogen peroxide is produced from the water inside the system. The closure of the cycle was estimated for individual elements and compounds. Stoichiometric proportions are given for the main components included in the experimental model of the system. Approaches to the mathematical modeling of the cycling processes are discussed, using the data of the experimental model. Nitrogen, as a representative of biogenic elements, shows an almost 100% closure of the cycle inside</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910021829','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910021829"><span>Flight tests with a data link used for <span class="hlt">air</span> traffic control information <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Knox, Charles E.; Scanlon, Charles H.</p> <p>1991-01-01</p> <p>Previous studies showed that <span class="hlt">air</span> traffic control (ATC) message <span class="hlt">exchange</span> with a data link offers the potential benefits of increased airspace system safety and efficiency. To accomplish these benefits, data link can be used to reduce communication errors and relieve overloaded ATC voice radio frequencies, which hamper efficient message <span class="hlt">exchange</span> during peak traffic periods. Flight tests with commercial airline pilots as test subjects were conducted in the NASA Transport Systems Research Vehicle Boeing 737 airplane to contrast flight operations that used current voice communications with flight operations that used data link to transmit both strategic and tactical ATC clearances during a typical commercial airflight from takeoff to landing. The results of these tests that used data link as the primary communication source with ATC showed flight crew acceptance, a perceived reduction in crew work load, and a reduction in crew communication errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3600394','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3600394"><span>Hydrogen-<span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry for the Study of Intrinsic Disorder in Proteins</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Balasubramaniam, Deepa; Komives, Elizabeth A.</p> <p>2012-01-01</p> <p>Amide hydrogen/deuterium <span class="hlt">exchange</span> detected by <span class="hlt">mass</span> spectrometry (HXMS) is seeing wider use for the identification of intrinsically disordered parts of proteins. In this review, we discuss examples of how discovery of intrinsically disordered regions and their removal can aid in structure determination, biopharmaceutical quality control, the characterization of how posttranslational modifications affect weak structuring of disordered regions, the study of coupled folding and binding, and the characterization of amyloid formation. PMID:23099262</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.908a2046X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.908a2046X"><span>Functional design of heat <span class="hlt">exchange</span> for pneumatic vehicles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Z. G.; Yang, D. Y.; Shen, W. D.; Liu, T. T.</p> <p>2017-10-01</p> <p>With the increasingly serious environmental problems, especially the impact of fog and haze, the development of <span class="hlt">air</span> powered vehicles has become an important research direction of new energy vehicles. Quadrature test was done with different materials, i.e. stainless steel and aluminum alloy, at different inlet pressures, using different expansion gases, i.e. <span class="hlt">air</span>, CO2, for heat <span class="hlt">exchanging</span> properties for pneumatic vehicles. The mathematics as well as simulation methods are used to analyze the different heat <span class="hlt">exchanging</span> effects in the multistage cylinder. The research results showed that the stainless steel has better effects in heat <span class="hlt">exchanging</span> than Aluminum Alloy; the intake pressure has little effect on CO2 than the <span class="hlt">air</span> in heat <span class="hlt">exchanging</span> effect. CO2 is better in heat <span class="hlt">exchanging</span> than <span class="hlt">air</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988asme.conf....2B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988asme.conf....2B"><span>Heat transfer and pressure drop measurements in an <span class="hlt">air</span>/molten salt direct-contact heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bohn, Mark S.</p> <p>1988-11-01</p> <p>This paper presents a comparison of experimental data with a recently published model of heat <span class="hlt">exchange</span> in irrigated packed beds. Heat transfer and pressure drop were measured in a 150 mm (ID) column with a 610 mm bed of metal Pall rings. Molten nitrate salt and preheated <span class="hlt">air</span> were the working fluids with a salt inlet temperature of approximately 440 C and <span class="hlt">air</span> inlet temperatures of approximately 230 C. A comparison between the experimental data and the heat transfer model is made on the basis of heat transfer from the salt. For the range of <span class="hlt">air</span> and salt flow rates tested, 0.3 to 1.2 kg/sq m/s <span class="hlt">air</span> flow and 6 to 18 kg/sq m/s salt flow, the data agree with the model within 22 percent standard deviation. In addition, a model for the column pressure drop was validated, agreeing with the experimental data within 18 percent standard deviation over the range of column pressure drop from 40 to 1250 Pa/m.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A32F..08C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A32F..08C"><span>Constraining the Stratosphere-Troposphere <span class="hlt">Exchange</span> of Radiocarbon using <span class="hlt">Air</span>Core 14CO2 Measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, H.</p> <p>2016-12-01</p> <p>Radiocarbon (14C) plays an important role in the carbon cycle studies to understand both natural and anthropogenic carbon fluxes, but also in atmospheric chemistry to constrain hydroxyl radical (OH) concentrations in the atmosphere. Apart from the enormous 14C emissions from nuclear bomb testing in the 1950s and 1960s, radiocarbon is primarily produced in the upper atmosphere due to reactions of nitrogen nuclei with thermal neutrons that are induced by cosmic rays. 14C is quickly oxidized to 14CO, which is then further oxidized to 14CO2 by OH. To this end, better understanding the radiocarbon source is very useful to advance the use of radiocarbon for these applications. However, upper atmospheric 14C observations have been very sparse to constrain the magnitude and the location of the 14C production as well as the transport of radiocarbon from the stratosphere to the troposphere. Recently we have successfully made stratospheric 14CO2 measurements using <span class="hlt">Air</span>Core samples from Sodankylä, Northern Finland, along with regular <span class="hlt">Air</span>Core profiles of CO2, CH4, and CO since 2013. In this study, we calculate the stratosphere-troposphere <span class="hlt">exchange</span> of 14C using the correlation between 14CO2 and N2O, and the estimated N2O loss rate. Besides this, we assess the impact of the mean age of <span class="hlt">air</span> on 14CO2 profiles. Furthermore, we will evaluate the influence of different cosmogenic 14C production scenarios and the uncertainties in the OH field on the seasonal cycles of radiocarbon and on the stratosphere-troposphere <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26ES...36a2056J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26ES...36a2056J"><span>Design and simulation of heat <span class="hlt">exchangers</span> using Aspen HYSYS, and Aspen <span class="hlt">exchanger</span> design and rating for paddy drying application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janaun, J.; Kamin, N. H.; Wong, K. H.; Tham, H. J.; Kong, V. V.; Farajpourlar, M.</p> <p>2016-06-01</p> <p><span class="hlt">Air</span> heating unit is one of the most important parts in paddy drying to ensure the efficiency of a drying process. In addition, an optimized <span class="hlt">air</span> heating unit does not only promise a good paddy quality, but also save more for the operating cost. This study determined the suitable and best specifications heating unit to heat <span class="hlt">air</span> for paddy drying in the LAMB dryer. In this study, Aspen HYSYS v7.3 was used to obtain the minimum flow rate of hot water needed. The resulting data obtained from Aspen HYSYS v7.3 were used in Aspen <span class="hlt">Exchanger</span> Design and Rating (EDR) to generate heat <span class="hlt">exchanger</span> design and costs. The designs include shell and tubes and plate heat <span class="hlt">exchanger</span>. The heat <span class="hlt">exchanger</span> was designed in order to produce various drying temperatures of 40, 50, 60 and 70°C of <span class="hlt">air</span> with different flow rate, 300, 2500 and 5000 LPM. The optimum condition for the heat <span class="hlt">exchanger</span> were found to be plate heat <span class="hlt">exchanger</span> with 0.6 mm plate thickness, 198.75 mm plate width, 554.8 mm plate length and 11 numbers of plates operating at 5000 LPM <span class="hlt">air</span> flow rate.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V43B3148X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V43B3148X"><span>Site-Specific Hydrogen Isotope Composition of Propane: <span class="hlt">Mass</span> spectrometric methods, equilibrium temperature dependence, and kinetics of <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, H.; Ponton, C.; Kitchen, N.; Lloyd, M. K.; Lawson, M.; Formolo, M. J.; Eiler, J. M.</p> <p>2016-12-01</p> <p>Intramolecular isotope ordering can constrain temperatures of synthesis, mechanisms of formation, and/or source substrates of organic compounds. Here we explore site-specific hydrogen isotope variations of propane. Statistical thermodynamic models predict that at equilibrium methylene hydrogen (-CH2-) in propane will be 10's of per mil higher in D/H ratio than methyl hydrogen (-CH3) at geologically relevant temperatures, and that this difference is highly temperature dependent ( 0.5-1 ‰/°C). Chemical-kinetic controls on site-specific D/H in propane could constrain the mechanisms, conditions and extents of propane synthesis or destruction. We have developed a method for measuring the difference in D/H ratio between methylene and methyl hydrogen in propane by gas source <span class="hlt">mass</span> spectrometry. The data were measured using the Thermo Fisher Double Focusing Sector high resolution <span class="hlt">mass</span> spectrometer (DFS), and involve comparison of the D/H ratios of molecular ion (C3H8+) and the ethyl fragmental ion (C2H5+). We demonstrate the accuracy and precision of this method through analysis of D-labeled and independently analyzed propanes. In the <span class="hlt">exchange</span> experiments, propane was heated (100-200 oC) either alone or in the presence of D-enriched water (δD=1,1419 ‰ SMOW), with or without one of several potentially catalytic substrates for hours to weeks. Propane was found to <span class="hlt">exchange</span> hydrogen with water vigorously at 200 °C in the presence of metal catalysts. In the presence of Ni catalyst, methylene hydrogen <span class="hlt">exchanges</span> 2.5 times faster than methyl hydrogen. Hydrogen <span class="hlt">exchange</span> in the presence of Pd catalyst is more effective and can equilibrate hydrogen isotope distribution on propane on the order of 7 days. Isotopic <span class="hlt">exchange</span> in the presence of natural materials have also been tested, but is only measurable in the methylene group at 200 °C. High catalytic activity of Pd permits attainment of a bracketed, time-invariant equilibrium state that we use to calibrate the site</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080026152&hterms=biofilm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbiofilm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080026152&hterms=biofilm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbiofilm"><span>Utilization of Porous Media for Condensing Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tuan, George C.</p> <p>2006-01-01</p> <p>The use of porous media as a mean of separating liquid condensate from the <span class="hlt">air</span> stream in condensing heat <span class="hlt">exchangers</span> has been explored in the past inside small plant growth chambers and in the Apollo Command Module. Both applications used a cooled porous media made of sintered stainless steel to cool and separate condensation from the <span class="hlt">air</span> stream. However, the main issues with the utilization of porous media in the past have been the deterioration of the porous media over long duration, such as clogging and changes in surface wetting characteristics. In addition, for long duration usage, biofilm growth from microorganisms on the porous medial would also be an issue. In developing Porous Media Condensing Heat <span class="hlt">Exchangers</span> (PMCHX) for future space applications, different porous materials and microbial growth control methods will need to be explored. This paper explores the work performed at JSC and GRC to evaluate different porous materials and microbial control methods to support the development of a Porous Media Condensing Heat <span class="hlt">Exchanger</span>. It outlines the basic principles for designing a PMCHX and issues that were encountered and ways to resolve those issues. The PMCHX has potential of <span class="hlt">mass</span>, volume, and power savings over current CHX and water separator technology and would be beneficial for long duration space missions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A13F2141B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A13F2141B"><span>Markers for Chinese and Korean <span class="hlt">Air</span> <span class="hlt">Masses</span>: Halocarbons and Other Trace Gases Measured During KORUS-AQ</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blake, N. J.; Blake, D. R.; Meinardi, S.; Simpson, I. J.; Hughes, S.; Barletta, B.; Fleming, L.; Vizenor, N.; Schroeder, J.; Emmons, L. K.; Knote, C. J.</p> <p>2017-12-01</p> <p>The UC-Irvine Whole <span class="hlt">Air</span> Sampler (WAS) collected a total of 2650 samples aboard the NASA DC-8 aircraft in support of the May-June 2016 field deployment phase of the KORUS-AQ mission: An International Cooperative <span class="hlt">Air</span> Quality Field Study in Korea. Here we employ our trace gas measurements, along with CAM-chem tracers and back-trajectories to identify source regions during KORUS-AQ, with a focus on <span class="hlt">air</span> <span class="hlt">masses</span> which indicate Chinese and/or Korean origin. During KORUS-AQ we flew mostly over and around the Korean Peninsula with the intent of characterising Korean sources, but Chinese influence was observed offshore near the surface of the West Sea during several KORUS-AQ flights - in accord with forecast predictions from CAM-chem model runs. Unlike previous missions in the Asian region such as TRACE-P (2001), we found that halon-1211 (H-1211) is no longer a useful indicator of <span class="hlt">air</span> <span class="hlt">masses</span> from China because of production decline. By contrast, mixing ratios of the long-lived halocarbons carbon tetrachloride (CCl4) and chlorofluorocarbon-113 (CFC-113) were more strongly enhanced in <span class="hlt">air</span> <span class="hlt">masses</span> intercepted from China compared to Korea. We will use these tracers, the shorter-lived halocarbons, dichloromethane (CH2Cl2) and methyl chloride (CH3Cl), as well as the sulfur gas carbonyl sulfide (COS) and others, to characterize different regional <span class="hlt">air</span> <span class="hlt">mass</span> origins and their sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19910095','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19910095"><span>Organochlorine pesticides in soils of Mexico and the potential for soil-<span class="hlt">air</span> <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wong, Fiona; Alegria, Henry A; Bidleman, Terry F</p> <p>2010-03-01</p> <p>The spatial distribution of organochlorine pesticides (OCs) in soils and their potential for soil-<span class="hlt">air</span> <span class="hlt">exchange</span> was examined. The most prominent OCs were the DDTs (Geometric Mean, GM=1.6 ng g(-1)), endosulfans (0.16 ng g(-1)), and toxaphenes (0.64 ng g(-1)). DDTs in soils of southern Mexico showed fresher signatures with higher FDDTe=p,p'-DDT/(p,p'-DDT+p,p'-DDE) and more racemic o,p'-DDT, while the signatures in the central and northern part of Mexico were more indicative of aged residues. Soil-<span class="hlt">air</span> fugacity fractions showed that some soils are net recipients of DDTs from the atmosphere, while other soils are net sources. Toxaphene profiles in soils and <span class="hlt">air</span> showed depletion of Parlar 39 and 42 which suggests that soil is the source to the atmosphere. Endosulfan was undergoing net deposition at most sites as it is a currently used pesticide. Other OCs showed wide variability in fugacity, suggesting a mix of net deposition and volatilization. Copyright (c) 2009 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28402293','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28402293"><span>Influence of relative <span class="hlt">air</span>/water flow velocity on oxygen <span class="hlt">mass</span> transfer in gravity sewers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carrera, Lucie; Springer, Fanny; Lipeme-Kouyi, Gislain; Buffiere, Pierre</p> <p>2017-04-01</p> <p>Problems related to hydrogen sulfide may be serious for both network stakeholders and the public in terms of health, sustainability of the sewer structure and urban comfort. H 2 S emission models are generally theoretical and simplified in terms of environmental conditions. Although <span class="hlt">air</span> transport characteristics in sewers must play a role in the fate of hydrogen sulfide, only a limited number of studies have investigated this issue. The aim of this study was to better understand H 2 S liquid to gas transfer by highlighting the link between the <span class="hlt">mass</span> transfer coefficient and the turbulence in the <span class="hlt">air</span> flow and the water flow. For experimental safety reasons, O 2 was taken as a model compound. The oxygen <span class="hlt">mass</span> transfer coefficients were obtained using a <span class="hlt">mass</span> balance in plug flow. The <span class="hlt">mass</span> transfer coefficient was not impacted by the range of the interface <span class="hlt">air</span>-flow velocity values tested (0.55-2.28 m·s -1 ) or the water velocity values (0.06-0.55 m·s -1 ). Using the ratio between k L,O 2 to k L,H 2 S , the H 2 S <span class="hlt">mass</span> transfer behavior in a gravity pipe in the same hydraulic conditions can be predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT........22V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT........22V"><span>Photochemical influences on the <span class="hlt">air</span>-water <span class="hlt">exchange</span> of mercury</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vette, Alan Frederic</p> <p></p> <p>The formation of dissolved gaseous mercury (DGM) in natural waters is an important component in the biogeochemical cycle of mercury (Hg). The predominate form of DGM in natural waters, gaseous elemental Hg (Hg0), may be transferred from the water to the atmosphere. Gas <span class="hlt">exchange</span> may reduce the amount of Hg available for methyl-Hg formation, the most toxic form of Hg that bioaccumulates in the food chain. Determining the mechanisms and rates of DGM formation is essential in understanding the fate and cycling of Hg in aquatic ecosystems. Field and laboratory experiments were conducted to evaluate the effect of light on DGM formation in surface waters containing different levels of dissolved organic carbon (DOC). Water samples collected from the Tahqwamenon River and Whitefish Bay on Lake Superior were amended with divalent Hg (Hg2+) and irradiated under a variety of reaction conditions to determine rates of DGM formation. The water samples were also analyzed for various Hg species (total, filtered, easily reducible and dissolved gaseous Hg), DOC and light attenuation. Additional field studies were conducted on Lake Michigan to measure gaseous Hg in <span class="hlt">air</span> and water. These data were used to develop a mechanistic model to estimate <span class="hlt">air</span>-water <span class="hlt">exchange</span> of gaseous Hg. This research found that photochemical formation of DGM was affected by penetration of UV A radiation (320-400 nm). Formation of DGM was enhanced at higher DOC concentrations, indicating DOC photosensitized the reduction of Hg2+ to Hg0. Wavelength studies determined that formation of DGM was significantly reduced in the absence of UV A. Field studies showed DGM concentrations were highest near the water surface and peaked at mid-day, indicating a photo-induced source of DGM. The conversion of reducible Hg2+ to Hg0 was suppressed in high DOC waters where UV A penetration was limited. The mechanistic model predicted similar DGM concentrations to the observed values and demonstrated that deposition and emission</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..217a2021D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..217a2021D"><span>Working parameters affecting earth-<span class="hlt">air</span> heat <span class="hlt">exchanger</span> (EAHE) system performance for passive cooling: A review</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Darius, D.; Misaran, M. S.; Rahman, Md. M.; Ismail, M. A.; Amaludin, A.</p> <p>2017-07-01</p> <p>The study on the effect of the working parameters such as pipe material, pipe length, pipe diameter, depth of burial of the pipe, <span class="hlt">air</span> flow rate and different types of soils on the thermal performance of earth-<span class="hlt">air</span> heat <span class="hlt">exchanger</span> (EAHE) systems is very crucial to ensure that thermal comfort can be achieved. In the past decade, researchers have performed studies to develop numerical models for analysis of EAHE systems. Until recently, two-dimensional models replaced the numerical models in the 1990s and in recent times, more advanced analysis using three-dimensional models, specifically the Computational Fluid Dynamics (CFD) simulation in the analysis of EAHE system. This paper reviews previous models used to analyse the EAHE system and working parameters that affects the earth-<span class="hlt">air</span> heat <span class="hlt">exchanger</span> (EAHE) thermal performance as of February 2017. Recent findings on the parameters affecting EAHE performance are also presented and discussed. As a conclusion, with the advent of CFD methods, investigational work have geared up to modelling and simulation work as it saves time and cost. Comprehension of the EAHE working parameters and its effect on system performance is largely established. However, the study on type of soil and its characteristics on the performance of EAHEs systems are surprisingly barren. Therefore, future studies should focus on the effect of soil characteristics such as moisture content, density of soil, and type of soil on the thermal performance of EAHEs system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EurSS..49.1400G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EurSS..49.1400G"><span>The influence of cryogenic <span class="hlt">mass</span> <span class="hlt">exchange</span> on the distribution of viable microfauna in cryozems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gubin, S. V.; Lupachev, A. V.; Shatilovich, A. V.; Myl'nikov, A. P.; Ryss, A. Yu.; Veremeeva, A. A.</p> <p>2016-12-01</p> <p>The role of cryogenic <span class="hlt">mass</span> <span class="hlt">exchange</span> in the distribution of the viable microfauna (ciliates, heterotrophic flagellates, and nematodes) in the profiles of cryoturbated cryogenic soils and in the upper layers of permafrost was revealed. The material for microbiological investigations was collected from the main horizons of cryozem profiles, including the zones with morphologically manifested processes of cryogenic <span class="hlt">mass</span> <span class="hlt">exchange</span> (the development of barren spots, cryoturbation, and suprapermafrost accumulation) and the zones affected by solifluction. The radiocarbon dating of the soil samples showed that the age of the organic cryogenic material and material buried in the course of solifluction varied from 2100 to 4500 years. Some zones with specific ecological conditions promoting the preservation of species diversity of the microfauna were found to develop in the cryozem profiles. A considerable part of the community (38% of ciliates, 58% of flagellates, and 50% of nematodes) maintained its viability in the dormant state, and in some cases, it could pass to the state of long-term cryobiosis in the upper layer of permafrost.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21275601','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21275601"><span>Vitreous web after pars plana vitrectomy and bevacizumab with fluid-<span class="hlt">air</span> <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chiang, Allen; Reddy, Shantan; Tsui, Irena; Hubschman, Jean-Pierre</p> <p>2011-01-01</p> <p>Intravitreal bevacizumab may result in intraocular inflammation of infectious and non-infectious etiology. Appropriate recognition of a sterile process can circumvent unnecessary treatment for endophthalmitis. Observational case report. A marked web-like inflammatory response within the vitreous following intraoperative intravitreal bevacizumab is described in a patient with pre-proliferative diabetic retinopathy, macular edema, and epiretinal membrane who underwent pars plana vitrectomy, membrane peel, endolaser, and fluid-<span class="hlt">air</span> <span class="hlt">exchange</span>. Wide-field fundus photography captured the full extent of this reaction. On post-operative day one, the patient presented with vitreous opacities in the form of a web of multiple white strands inferior to an <span class="hlt">air</span> bubble, with minimal anterior or vitreous cell. At one week, the inflammatory reaction had completely resolved. Existing reports of intraocular inflammation following intravitreal bevacizumab range from uveitis to infectious endophthalmitis. With wide-field fundus imaging, we report an acute, marked web-like inflammatory response following intraoperative intravitreal bevacizumab that resolved spontaneously.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A43H3373K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A43H3373K"><span>Direct observations of Biogenic Volatile Organic Compound (BVOC) <span class="hlt">Air</span>-Sea <span class="hlt">Exchange</span> in the remote North Atlantic from the High-Wind Gas-<span class="hlt">Exchange</span> Study (HiWinGS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, M.; Yang, M. X.; Blomquist, B.; Huebert, B. J.; Bertram, T. H.</p> <p>2014-12-01</p> <p>Biogenic Volatile Organic Compounds (BVOCs) are reactive trace gases that impact both chemistry and climate by regulating oxidant loadings, determining secondary organic aerosol production rates as well as altering particle hygroscopicity. While continental BVOC <span class="hlt">exchange</span> rates are well studied, global marine flux estimates are poorly constrained. In Fall 2013, a chemical-ionization time-of-flight <span class="hlt">mass</span> spectrometer (CI-ToF-MS) utilizing benzene cations was deployed as part of the High Wind Gas <span class="hlt">Exchange</span> Study (HiWinGs) to quantify monoterpenes, isoprene and dimethylsulfide fluxes in the remote North Atlantic. Dimethylsulfide measurements are in strong agreement with those determined by the University of Hawaii's atmospheric pressure ionization <span class="hlt">mass</span>-spectrometer. In the remote marine boundary layer, positive monoterpene fluxes (i.e. emissions) were observed while isoprene levels rarely exceeded the detection limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26717885','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26717885"><span>Two-step ion-<span class="hlt">exchange</span> chromatographic purification combined with reversed-phase chromatography to isolate C-peptide for <span class="hlt">mass</span> spectrometric analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kabytaev, Kuanysh; Durairaj, Anita; Shin, Dmitriy; Rohlfing, Curt L; Connolly, Shawn; Little, Randie R; Stoyanov, Alexander V</p> <p>2016-02-01</p> <p>A liquid chromatography with <span class="hlt">mass</span> spectrometry on-line platform that includes the orthogonal techniques of ion <span class="hlt">exchange</span> and reversed phase chromatography is applied for C-peptide analysis. Additional improvement is achieved by the subsequent application of cation- and anion-<span class="hlt">exchange</span> purification steps that allow for isolating components that have their isoelectric points in a narrow pH range before final reversed-phase <span class="hlt">mass</span> spectrometry analysis. The utility of this approach for isolating fractions in the desired "pI window" for profiling complex mixtures is discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JASMS..27...83Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JASMS..27...83Z"><span>Localizing Carbohydrate Binding Sites in Proteins Using Hydrogen/Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Jingjing; Kitova, Elena N.; Li, Jun; Eugenio, Luiz; Ng, Kenneth; Klassen, John S.</p> <p>2016-01-01</p> <p>The application of hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) to localize ligand binding sites in carbohydrate-binding proteins is described. Proteins from three bacterial toxins, the B subunit homopentamers of Cholera toxin and Shiga toxin type 1 and a fragment of Clostridium difficile toxin A, and their interactions with native carbohydrate receptors, GM1 pentasaccharides (β-Gal-(1→3)-β-GalNAc-(1→4)[α-Neu5Ac-(2→3)]-β-Gal-(1→4)-Glc), Pk trisaccharide (α-Gal-(1→4)-β-Gal-(1→4)-Glc) and CD-grease (α-Gal-(1→3)-β-Gal-(1→4)-β-GlcNAcO(CH2)8CO2CH3), respectively, served as model systems for this study. Comparison of the differences in deuterium uptake for peptic peptides produced in the absence and presence of ligand revealed regions of the proteins that are protected against deuterium <span class="hlt">exchange</span> upon ligand binding. Notably, protected regions generally coincide with the carbohydrate binding sites identified by X-ray crystallography. However, ligand binding can also result in increased deuterium <span class="hlt">exchange</span> in other parts of the protein, presumably through allosteric effects. Overall, the results of this study suggest that HDX-MS can serve as a useful tool for localizing the ligand binding sites in carbohydrate-binding proteins. However, a detailed interpretation of the changes in deuterium <span class="hlt">exchange</span> upon ligand binding can be challenging because of the presence of ligand-induced changes in protein structure and dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140016490','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140016490"><span>The Use of Red Green Blue <span class="hlt">Air</span> <span class="hlt">Mass</span> Imagery to Investigate the Role of Stratospheric <span class="hlt">Air</span> in a Non-Convective Wind Event</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berndt, E. B.; Zavodsky, B. T.; Moltham, A. L.; Folmer, M. J.; Jedlovec, G. J.</p> <p>2014-01-01</p> <p>The investigation of non-convective winds associated with passing extratropical cyclones and the formation of the sting jet in North Atlantic cyclones that impact Europe has been gaining interest. Sting jet research has been limited to North Atlantic cyclones that impact Europe because it is known to occur in Shapiro-Keyser cyclones and theory suggests it does not occur in Norwegian type cyclones. The global distribution of sting jet cyclones is unknown and questions remain as to whether cyclones with Shapiro-Keyser characteristics that impact the United States develop features similar to the sting jet. Therefore unique National Aeronautics and Space Administration (NASA) products were used to analyze an event that impacted the Northeast United States on 09 February 2013. Moderate Resolution Imaging Spectroradiometer (MODIS) Red Green Blue (RGB) <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery and Atmospheric Infrared Sounder (<span class="hlt">AIRS</span>) ozone data were used in conjunction with NASA's global Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis and higher-resolution regional 13-km Rapid Refresh (RAP) data to analyze the role of stratospheric <span class="hlt">air</span> in producing high winds. The RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery and a new <span class="hlt">AIRS</span> ozone anomaly product were used to confirm the presence of stratospheric <span class="hlt">air</span>. Plan view and cross sectional plots of wind, potential vorticity, relative humidity, omega, and frontogenesis were used to analyze the relationship between stratospheric <span class="hlt">air</span> and high surface winds during the event. Additionally, the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to plot trajectories to determine the role of the conveyor belts in producing the high winds. Analyses of new satellite products, such as the RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery, show the utility of future GOES-R products in forecasting non-convective wind events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A23A0183Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A23A0183Z"><span>An <span class="hlt">Air</span> <span class="hlt">Mass</span> Based Approach to the Establishment of Spring Season Synoptic Characteristics in the Northeast United States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zander, R.; Messina, A.; Godek, M. L.</p> <p>2012-12-01</p> <p>The spring season is indicative of marked meteorological, ecological, and biological changes across the Northeast United States. The onset of spring coincides with distinct meteorological phenomena including an increase in severe weather events and snow meltwaters that can cause localized flooding and other costly damages. Increasing and variable springtime temperatures also influence Northeast tourist operations and agricultural productivity. Even with the vested interest of industry in the season and public awareness of the dynamic characteristics of spring, the definition of spring remains somewhat arbitrary. The primary goal of this research is to obtain a synoptic meteorological definition of the spring season through an assessment of <span class="hlt">air</span> <span class="hlt">mass</span> frequency over the past 60 years. A secondary goal examines the validity of recent speculations that the onset and termination of spring has changed in recent decades, particularly since 1975. The Spatial Synoptic Classification is utilized to define daily <span class="hlt">air</span> <span class="hlt">masses</span> over the region. Annual and seasonal baseline frequencies are identified and their differences are acquired to characterize the season. Seasonal frequency departures of the early and late segments of the period of record around 1975 are calculated and examined for practical and statistical significance. The daily boundaries of early and late spring are then isolated and frequencies are obtained for these periods. Boundary frequencies are assessed across the period of record to identify important changes in the season's initiation and termination through time. Results indicate that the Northeast spring season is dominated by dry <span class="hlt">air</span> <span class="hlt">masses</span>, mainly the Dry Moderate and Dry Polar types. Significant differences in seasonal <span class="hlt">air</span> <span class="hlt">mass</span> frequency are also observed through time. Prior to 1975, higher frequencies of polar <span class="hlt">air</span> <span class="hlt">mass</span> types are detected while after 1975 there is an increase in the frequencies of both moderate and tropical types. This finding is also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=255244&keyword=temperature+AND+variability&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=255244&keyword=temperature+AND+variability&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Identifying Housing and Meteorological Conditions Influencing Residential <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rates in the DEARS and RIOPA Studies: Development of Distributions for Human Exposure Modeling</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Appropriate prediction of residential <span class="hlt">air</span> <span class="hlt">exchange</span> rate (AER) is important for estimating human exposures in the residential microenvironment, as AER drives the infiltration of outdoor-generated <span class="hlt">air</span> pollutants indoors. AER differences among homes may result from a number of fact...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ACP....14.9903C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ACP....14.9903C"><span>Characterising terrestrial influences on Antarctic <span class="hlt">air</span> <span class="hlt">masses</span> using Radon-222 measurements at King George Island</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chambers, S. D.; Hong, S.-B.; Williams, A. G.; Crawford, J.; Griffiths, A. D.; Park, S.-J.</p> <p>2014-09-01</p> <p>We report on one year of high-precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m-3 in late-summer to 44 mBq m-3 in late winter and early spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m-3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced <span class="hlt">air</span> <span class="hlt">masses</span> was South America (47-53° S), with minor influences also attributed to aged Australian <span class="hlt">air</span> <span class="hlt">masses</span> and local sources. Plume dilution factors of 2.8-4.0 were estimated for the most terrestrially influenced (South American) <span class="hlt">air</span> <span class="hlt">masses</span>, and a seasonal cycle in terrestrial influence on tropospheric <span class="hlt">air</span> descending at the pole was identified and characterised.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ACPD...1411541C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ACPD...1411541C"><span>Characterising terrestrial influences on Antarctic <span class="hlt">air</span> <span class="hlt">masses</span> using radon-222 measurements at King George Island</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chambers, S. D.; Hong, S.-B.; Williams, A. G.; Crawford, J.; Griffiths, A. D.; Park, S.-J.</p> <p>2014-05-01</p> <p>We report on one year of high precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m-3 in late summer to 44 mBq m-3 in late-winter and early-spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m-3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced <span class="hlt">air</span> <span class="hlt">masses</span> was South America (47-53° S), with minor influences also attributed to aged Australian <span class="hlt">air</span> <span class="hlt">masses</span> and local sources. Plume dilution factors of 2.8-4.0 were estimated for the most terrestrially influenced (South American) <span class="hlt">air</span> <span class="hlt">masses</span>, and a seasonal cycle in terrestrial influence on tropospheric <span class="hlt">air</span> descending at the pole was identified and characterised.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17124141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17124141"><span>Analysis of heat and <span class="hlt">mass</span> transfer during condensation over a porous substrate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Balasubramaniam, R; Nayagam, V; Hasan, M M; Khan, L</p> <p>2006-09-01</p> <p>Condensing heat <span class="hlt">exchangers</span> are important in many space applications for thermal and humidity control systems. The International Space Station uses a cooled fin surface to condense moisture from humid <span class="hlt">air</span> that is blown over it. The condensate and the <span class="hlt">air</span> are "slurped" into a system that separates <span class="hlt">air</span> and water by centrifugal forces. The use of a cooled porous substrate is an attractive alternative to the fin where condensation and liquid/gas separation can be achieved in a single step. We analyze the heat and <span class="hlt">mass</span> transfer during condensation of moisture from flowing <span class="hlt">air</span> over such a cooled, flat, porous substrate. A fully developed regime is investigated for coupled <span class="hlt">mass</span>, momentum and energy transport in the gas phase, and momentum and energy transport in the condensate layer on the porous substrate and through the porous medium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17706251','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17706251"><span><span class="hlt">Air</span>--sea gaseous <span class="hlt">exchange</span> of PCB at the Venice lagoon (Italy).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Manodori, L; Gambaro, A; Moret, I; Capodaglio, G; Cescon, P</p> <p>2007-10-01</p> <p>Water bodies are important storage media for persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) and this function is increased in coastal regions because their inputs are higher than those to the open sea. The <span class="hlt">air</span>-water interface is extensively involved with the global cycling of PCBs because it is the place where they accumulate due to depositional processes and where they may be emitted by gaseous <span class="hlt">exchange</span>. In this work the parallel collection of <span class="hlt">air</span>, microlayer and sub-superficial water samples was performed in July 2005 at a site in the Venice lagoon to evaluate the summer gaseous flux of PCBs. The total concentration of PCBs (sum of 118 congeners) in <span class="hlt">air</span> varies from 87 to 273 pg m(-3), whereas in the operationally defined dissolved phase of microlayer and sub-superficial water samples it varies from 159 to 391 pg L(-1). No significant enrichment of dissolved PCB into the microlayer has been observed, although a preferential accumulation of most hydrophobic congeners occurs. Due to this behaviour, we believe that the modified two-layer model was the most suitable approach for the evaluation of the flux at the <span class="hlt">air</span>-sea interface, because it takes into account the influence of the microlayer. From its application it appears that PCB volatilize from the lagoon waters with a net flux varying from 58 to 195 ng m(-2)d(-1) (uncertainty: +/-50-64%) due to the strong influence of wind speed. This flux is greater than those reported in the literature for the atmospheric deposition and rivers input and reveals that PCB are actively emitted from the Venice lagoon in summer months.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5544108','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5544108"><span>Analysis of phosphoinositide 3-kinase inhibitors by bottom-up electron-transfer dissociation hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Masson, Glenn R.; Maslen, Sarah L.</p> <p>2017-01-01</p> <p>Until recently, one of the major limitations of hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) was the peptide-level resolution afforded by proteolytic digestion. This limitation can be selectively overcome through the use of electron-transfer dissociation to fragment peptides in a manner that allows the retention of the deuterium signal to produce hydrogen/deuterium <span class="hlt">exchange</span> tandem <span class="hlt">mass</span> spectrometry (HDX-MS/MS). Here, we describe the application of HDX-MS/MS to structurally screen inhibitors of the oncogene phosphoinositide 3-kinase catalytic p110α subunit. HDX-MS/MS analysis is able to discern a conserved mechanism of inhibition common to a range of inhibitors. Owing to the relatively minor amounts of protein required, this technique may be utilised in pharmaceutical development for screening potential therapeutics. PMID:28381646</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880025659&hterms=water+effects&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dwater%2Beffects','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880025659&hterms=water+effects&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dwater%2Beffects"><span>Seasonal <span class="hlt">air</span> and water <span class="hlt">mass</span> redistribution effects on LAGEOS and Starlette</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gutierrez, Roberto; Wilson, Clark R.</p> <p>1987-01-01</p> <p>Zonal geopotential coefficients have been computed from average seasonal variations in global <span class="hlt">air</span> and water <span class="hlt">mass</span> distribution. These coefficients are used to predict the seasonal variations of LAGEOS' and Starlette's orbital node, the node residual, and the seasonal variation in the 3rd degree zonal coefficient for Starlette. A comparison of these predictions with the observed values indicates that <span class="hlt">air</span> pressure and, to a lesser extent, water storage may be responsible for a large portion of the currently unmodeled variation in the earth's gravity field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ACP....18.6661K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ACP....18.6661K"><span>Photochemical aging of aerosol particles in different <span class="hlt">air</span> <span class="hlt">masses</span> arriving at Baengnyeong Island, Korea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kang, Eunha; Lee, Meehye; Brune, William H.; Lee, Taehyoung; Park, Taehyun; Ahn, Joonyoung; Shang, Xiaona</p> <p>2018-05-01</p> <p>Atmospheric aerosol particles are a serious health risk, especially in regions like East Asia. We investigated the photochemical aging of ambient aerosols using a potential aerosol <span class="hlt">mass</span> (PAM) reactor at Baengnyeong Island in the Yellow Sea during 4-12 August 2011. The size distributions and chemical compositions of aerosol particles were measured alternately every 6 min from the ambient <span class="hlt">air</span> or through the highly oxidizing environment of a potential aerosol <span class="hlt">mass</span> (PAM) reactor. Particle size and chemical composition were measured by using the combination of a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol <span class="hlt">mass</span> spectrometer (HR-ToF-AMS). Inside the PAM reactor, O3 and OH levels were equivalent to 4.6 days of integrated OH exposure at typical atmospheric conditions. Two types of <span class="hlt">air</span> <span class="hlt">masses</span> were distinguished on the basis of the chemical composition and the degree of aging: <span class="hlt">air</span> transported from China, which was more aged with a higher sulfate concentration and O : C ratio, and the <span class="hlt">air</span> transported across the Korean Peninsula, which was less aged with more organics than sulfate and a lower O : C ratio. For both episodes, the particulate sulfate <span class="hlt">mass</span> concentration increased in the 200-400 nm size range when sampled through the PAM reactor. A decrease in organics was responsible for the loss of <span class="hlt">mass</span> concentration in 100-200 nm particles when sampled through the PAM reactor for the organics-dominated episode. This loss was especially evident for the m/z 43 component, which represents less oxidized organics. The m/z 44 component, which represents further oxidized organics, increased with a shift toward larger sizes for both episodes. It is not possible to quantify the maximum possible organic <span class="hlt">mass</span> concentration for either episode because only one OH exposure of 4.6 days was used, but it is clear that SO2 was a primary precursor of secondary aerosol in northeast Asia, especially during long-range transport from China. In addition</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24037179','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24037179"><span>Determining the ventilation and aerosol deposition rates from routine indoor-<span class="hlt">air</span> measurements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Halios, Christos H; Helmis, Costas G; Deligianni, Katerina; Vratolis, Sterios; Eleftheriadis, Konstantinos</p> <p>2014-01-01</p> <p>Measurement of <span class="hlt">air</span> <span class="hlt">exchange</span> rate provides critical information in energy and indoor-<span class="hlt">air</span> quality studies. Continuous measurement of ventilation rates is a rather costly exercise and requires specific instrumentation. In this work, an alternative methodology is proposed and tested, where the <span class="hlt">air</span> <span class="hlt">exchange</span> rate is calculated by utilizing indoor and outdoor routine measurements of a common pollutant such as SO2, whereas the uncertainties induced in the calculations are analytically determined. The application of this methodology is demonstrated, for three residential microenvironments in Athens, Greece, and the results are also compared against ventilation rates calculated from differential pressure measurements. The calculated time resolved ventilation rates were applied to the <span class="hlt">mass</span> balance equation to estimate the particle loss rate which was found to agree with literature values at an average of 0.50 h(-1). The proposed method was further evaluated by applying a <span class="hlt">mass</span> balance numerical model for the calculation of the indoor aerosol number concentrations, using the previously calculated ventilation rate, the outdoor measured number concentrations and the particle loss rates as input values. The model results for the indoors' concentrations were found to be compared well with the experimentally measured values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3799349','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3799349"><span>Protein hydrogen <span class="hlt">exchange</span> at residue resolution by proteolytic fragmentation <span class="hlt">mass</span> spectrometry analysis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kan, Zhong-Yuan; Walters, Benjamin T.; Mayne, Leland; Englander, S. Walter</p> <p>2013-01-01</p> <p>Hydrogen <span class="hlt">exchange</span> technology provides a uniquely powerful instrument for measuring protein structural and biophysical properties, quantitatively and in a nonperturbing way, and determining how these properties are implemented to produce protein function. A developing hydrogen exchange–<span class="hlt">mass</span> spectrometry method (HX MS) is able to analyze large biologically important protein systems while requiring only minuscule amounts of experimental material. The major remaining deficiency of the HX MS method is the inability to deconvolve HX results to individual amino acid residue resolution. To pursue this goal we used an iterative optimization program (HDsite) that integrates recent progress in multiple peptide acquisition together with previously unexamined isotopic envelope-shape information and a site-resolved back-<span class="hlt">exchange</span> correction. To test this approach, residue-resolved HX rates computed from HX MS data were compared with extensive HX NMR measurements, and analogous comparisons were made in simulation trials. These tests found excellent agreement and revealed the important computational determinants. PMID:24019478</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AcSpe.135...82S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AcSpe.135...82S"><span>Optimization of collision/reaction gases for determination of 90Sr in atmospheric particulate matter by inductively coupled plasma tandem <span class="hlt">mass</span> spectrometry after direct introduction of <span class="hlt">air</span> via a gas-<span class="hlt">exchange</span> device</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suzuki, Yoshinari; Ohara, Ryota; Matsunaga, Kirara</p> <p>2017-09-01</p> <p>Nuclear power plant accidents release radioactive strontium 90 (90Sr) into the environment. Monitoring of 90Sr, although important, is difficult and time consuming because it emits only beta radiation. We have developed a new analytical system that enables real-time analysis of 90Sr in atmospheric particulate matter with an analytical run time of only 10 min. Briefly, after passage of an <span class="hlt">air</span> sample through an impactor, a small fraction of the sample is introduced into a gas-<span class="hlt">exchange</span> device, where the <span class="hlt">air</span> is replaced by Ar. Then the sample is directly introduced into an inductively coupled plasma tandem <span class="hlt">mass</span> spectrometry (ICP-MS/MS) system equipped with a collision/reaction cell to eliminate isobaric interferences on 90Sr from 90Zr+, 89Y1H+, and 90Y+. Experiments with various reaction gas conditions revealed that these interferences could be minimized under the following optimized conditions: 1.0 mL min- 1 O2, 10.0 mL min- 1 H2, and 1.0 mL min- 1 NH3. The estimated background equivalent concentration and estimated detection limit of the system were 9.7 × 10- 4 and 3.6 × 10- 4 ng m- 3, respectively, which are equivalent to 4.9 × 10- 6 and 1.8 × 10- 6 Bq cm- 3. Recoveries of Sr in PM2.5 measured by real-time analysis compared to those obtained by simultaneously collection on filter was 53 ± 23%, and using this recovery, the detection limit as PM2.5 was estimated to be 3.4 ± 1.5 × 10- 6 Bq cm- 3. That is, this system enabled detection of 90Sr at concentrations < 5 × 10- 6 Bq cm- 3 even considering the insufficient fusion/vaporization/ionization efficiency of Sr in PM2.5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MsT.........35W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MsT.........35W"><span>Investigation of Various Novel <span class="hlt">Air</span>-Breathing Propulsion Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilhite, Jarred M.</p> <p></p> <p>The current research investigates the operation and performance of various <span class="hlt">air</span>-breathing propulsion systems, which are capable of utilizing different types of fuel. This study first focuses on a modular RDE configuration, which was mainly studied to determine which conditions yield stable, continuous rotating detonation for an ethylene-<span class="hlt">air</span> mixture. The performance of this RDE was analyzed by studying various parameters such as <span class="hlt">mass</span> flow rate, equivalence ratios, wave speed and cell size. For relatively low <span class="hlt">mass</span> flow rates near stoichiometric conditions, a rotating detonation wave is observed for an ethylene-RDE, but at speeds less than an ideal detonation wave. The current research also involves investigating the newly designed, Twin Oxidizer Injection Capable (TOXIC) RDE. Mixtures of hydrogen and <span class="hlt">air</span> were utilized for this configuration, resulting in sustained rotating detonation for various <span class="hlt">mass</span> flow rates and equivalence ratios. A thrust stand was also developed to observe and further measure the performance of the TOXIC RDE. Further analysis was conducted to accurately model and simulate the response of thrust stand during operation of the RDE. Also included in this research are findings and analysis of a propulsion system capable of operating on the Inverse Brayton Cycle. The feasibility of this novel concept was validated in a previous study to be sufficient for small-scale propulsion systems, namely UAV applications. This type of propulsion system consists of a reorganization of traditional gas turbine engine components, which incorporates expansion before compression. This cycle also requires a heat <span class="hlt">exchanger</span> to reduce the temperature of the flow entering the compressor downstream. While adding a heat <span class="hlt">exchanger</span> improves the efficiency of the cycle, it also increases the engine weight, resulting in less endurance for the aircraft. Therefore, this study focuses on the selection and development of a new heat <span class="hlt">exchanger</span> design that is lightweight, and is capable</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013594','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013594"><span>Miniature Distillation Column for Producing LOX From <span class="hlt">Air</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rozzi, Jay C.</p> <p>2006-01-01</p> <p>The figure shows components of a distillation column intended for use as part of a system that produces high-purity liquid oxygen (LOX) from <span class="hlt">air</span> by distillation. (The column could be easily modified to produce high-purity liquid nitrogen.) Whereas typical industrial distillation columns for producing high-purity liquid oxygen and/or nitrogen are hundreds of feet tall, this distillation column is less than 3 ft (less than about 0.9 m) tall. This column was developed to trickle-charge a LOX-based emergency oxygen system (EOS) for a large commercial aircraft. A description of the industrial production of liquid oxygen and liquid nitrogen by distillation is prerequisite to a meaningful description of the present miniaturized distillation column. Typically, such industrial production takes place in a chemical processing plant in which large quantities of high-pressure <span class="hlt">air</span> are expanded in a turboexpander to (1) recover a portion of the electrical power required to compress the <span class="hlt">air</span> and (2) partially liquefy the <span class="hlt">air</span>. The resulting two-phase flow of <span class="hlt">air</span> is sent to the middle of a distillation column. The liquid phase is oxygen-rich, and its oxygen purity increases as it flows down the column. The vapor phase is nitrogen-rich and its nitrogen purity increases as it flows up the column. A heater or heat <span class="hlt">exchanger</span>, commonly denoted a reboiler, is at the bottom of the column. The reboiler is so named because its role is to reboil some of the liquid oxygen collected at the bottom of the column to provide a flow of oxygen-rich vapor. As the oxygen-rich vapor flows up the column, it absorbs the nitrogen in the down-flowing liquid by <span class="hlt">mass</span> transfer. Once the vapor leaves the lower portion of the column, it interacts with down-flowing nitrogen liquid that has been condensed in a heat <span class="hlt">exchanger</span>, commonly denoted a condenser, at the top of the column. Liquid oxygen and liquid nitrogen products are obtained by draining some of the purified product at the bottom and top of the column</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080015925','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080015925"><span>Establishing Lagrangian Connections between Observations within <span class="hlt">Air</span> <span class="hlt">Masses</span> Crossing the Atlantic during the ICARTT Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Methven, J.; Arnold, S. R.; Stohl, A.; Evans, M. J.; Avery, M.; Law, K.; Lewis, A. C.; Monks, P. S.; Parrish, D.; Reeves, C.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20080015925'); toggleEditAbsImage('author_20080015925_show'); toggleEditAbsImage('author_20080015925_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20080015925_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20080015925_hide"></p> <p>2006-01-01</p> <p>The International Consortium for Atmospheric Research on Transport and Transformation (ICARTT)-Lagrangian experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of <span class="hlt">air</span> <span class="hlt">masses</span> in the free troposphere away from emissions. To this end attempts were made to intercept and sample <span class="hlt">air</span> <span class="hlt">masses</span> several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts using two Lagrangian models that were used to direct the aircraft into target <span class="hlt">air</span> <span class="hlt">masses</span>. A novel technique is then used to identify Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole <span class="hlt">air</span> samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these coincident matches is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown and the downwind minus upwind differences in tracers are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4674977','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4674977"><span>Estimation of bias with the single-zone assumption in measurement of residential <span class="hlt">air</span> <span class="hlt">exchange</span> using the perfluorocarbon tracer gas method</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Van Ryswyk, K; Wallace, L; Fugler, D; MacNeill, M; Héroux, M È; Gibson, M D; Guernsey, J R; Kindzierski, W; Wheeler, A J</p> <p>2015-01-01</p> <p>Residential <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AERs) are vital in understanding the temporal and spatial drivers of indoor <span class="hlt">air</span> quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed <span class="hlt">air</span> zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER1z). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER2z). In total, 287 daily pairs of AER2z and AER1z estimates were made from 35 homes across three cities. In 87% of the cases, AER2z was higher than AER1z. Overall, the AER1z estimates underestimated AER2z by approximately 16% (IQR: 5–32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential <span class="hlt">air</span> <span class="hlt">exchange</span> using a single PFT gas, the assumption of a single well-mixed <span class="hlt">air</span> zone very likely results in an under prediction of the AER. PMID:25399878</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110000601','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110000601"><span><span class="hlt">Air</span> Circulation and Heat <span class="hlt">Exchange</span> Under Reduced Pressures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rygalov, V.; Wheeler, R.; Dixon, M.; Fowler, P.; Hillhouse, L.</p> <p>2010-01-01</p> <p>Heat <span class="hlt">exchange</span> rates decrease non-linearly with reductions in atmospheric pressure. This decrease creates risk of thermal stress (elevated leaf temperatures) for plants under reduced pressures. Forced convection (fans) significantly increases heat <span class="hlt">exchange</span> rate under almost all pressures except below 10 kPa. Plant cultivation techniques under reduced pressures will require forced convection. The cooling curve technique is a reliable means of assessing the influence of environmental variables like pressure and gravity on gas <span class="hlt">exchange</span> of plant. These results represent the extremes of gas <span class="hlt">exchange</span> conditions for simple systems under variable pressures. In reality, dense plant canopies will exhibit responses in between these extremes. More research is needed to understand the dependence of forced convection on atmospheric pressure. The overall thermal balance model should include latent and radiative <span class="hlt">exchange</span> components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol11/pdf/CFR-2013-title40-vol11-sec63-654.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol11/pdf/CFR-2013-title40-vol11-sec63-654.pdf"><span>40 CFR 63.654 - Heat <span class="hlt">exchange</span> systems.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>...) through (g) of this section if all heat <span class="hlt">exchangers</span> within the heat <span class="hlt">exchange</span> system either: (1) Operate... exposure to <span class="hlt">air</span> for each heat <span class="hlt">exchange</span> system. (ii) Selected heat <span class="hlt">exchanger</span> exit line(s) so that each heat <span class="hlt">exchanger</span> or group of heat <span class="hlt">exchangers</span> within a heat <span class="hlt">exchange</span> system is covered by the selected monitoring...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol11/pdf/CFR-2014-title40-vol11-sec63-654.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol11/pdf/CFR-2014-title40-vol11-sec63-654.pdf"><span>40 CFR 63.654 - Heat <span class="hlt">exchange</span> systems.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>...) through (g) of this section if all heat <span class="hlt">exchangers</span> within the heat <span class="hlt">exchange</span> system either: (1) Operate... exposure to <span class="hlt">air</span> for each heat <span class="hlt">exchange</span> system. (ii) Selected heat <span class="hlt">exchanger</span> exit line(s) so that each heat <span class="hlt">exchanger</span> or group of heat <span class="hlt">exchangers</span> within a heat <span class="hlt">exchange</span> system is covered by the selected monitoring...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JBIS...60..188W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JBIS...60..188W"><span>The Sensitivity of Precooled <span class="hlt">Air</span>-Breathing Engine Performance to Heat <span class="hlt">Exchanger</span> Design Parameters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Webber, H.; Bond, A.; Hempsell, M.</p> <p></p> <p>The issues relevant to propulsion design for Single Stage To Orbit (SSTO) vehicles are considered. In particular two <span class="hlt">air</span>- breathing engine concepts involving precooling are compared; SABRE (Synergetic <span class="hlt">Air</span>-Breathing and Rocket Engine) as designed for the Skylon SSTO launch vehicle, and a LACE (Liquid <span class="hlt">Air</span> Cycle Engine) considered in the 1960's by the Americans for an early generation spaceplane. It is shown that through entropy minimisation the SABRE has made substantial gains in performance over the traditional LACE precooled engine concept, and has shown itself as the basis of a viable means of realising a SSTO vehicle. Further, it is demonstrated that the precooler is a major source of thermodynamic irreversibility within the engine cycle and that further reduction in entropy can be realised by increasing the heat transfer coefficient on the <span class="hlt">air</span> side of the precooler. If this were to be achieved, it would improve the payload <span class="hlt">mass</span> delivered to orbit by the Skylon launch vehicle by between 5 and 10%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=308472&Lab=NERL&keyword=simulation+AND+processes&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=308472&Lab=NERL&keyword=simulation+AND+processes&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Development and Evaluation of a New <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rate Algorithm for the Stochastic Human Exposure and Dose Simulation Model</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>between-home and between-city variability in residential pollutant infiltration. This is likely a result of differences in home ventilation, or <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AER). The Stochastic Human Exposure and Dose Simulation (SHEDS) model is a population exposure model that uses a pro...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15732932','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15732932"><span><span class="hlt">Mass</span> spectrometer characterization of halogen gases in <span class="hlt">air</span> at atmospheric pressure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ivey, Michelle M; Foster, Krishna L</p> <p>2005-03-01</p> <p>We have developed a new interface for a commercial ion trap <span class="hlt">mass</span> spectrometer equipped with APCI capable of real-time measurements of gaseous compounds with limits of detection on the order of pptv. The new interface has been tested using the detection of Br2 and Cl2 over synthetic seawater ice at atmospheric pressure as a model system. A mechanical pump is used to draw gaseous mixtures through a glass manifold into the corona discharge area, where the molecules are ionized. Analysis of bromine and chlorine in dry <span class="hlt">air</span> show that ion intensity is affected by the pumping rate and the position of the glass manifold. The <span class="hlt">mass</span> spectrometer signals for Br2 are linear in the 0.1-10.6 ppbv range, and the estimated 3sigma detection limit is 20 pptv. The MS signals for Cl2 are linear in the 0.2-25 ppbv range, and the estimated 3sigma detection limit is 1 ppbv. This new interface advances the field of analytical chemistry by introducing a practical modification to a commercially available ion trap <span class="hlt">mass</span> spectrometer that expands the available methods for performing highly specific and sensitive measurements of gases in <span class="hlt">air</span> at atmospheric pressure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950031278&hterms=biomass+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbiomass%2Bproduction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950031278&hterms=biomass+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbiomass%2Bproduction"><span>Enhancement of acidic gases in biomass burning impacted <span class="hlt">air</span> <span class="hlt">masses</span> over Canada</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lefer, B. L.; Talbot, R. W.; Harriss, R. C.; Bradshaw, J. D.; Sandholm, S. T.; Olson, J. O.; Sachse, G. W.; Collins, J.; Shipham, M. A.; Blake, D. R.</p> <p>1994-01-01</p> <p>Biomass-burning impacted <span class="hlt">air</span> <span class="hlt">masses</span> sampled over central and eastern Canada during the summer of 1990 as part of ABLE 3B contained enhanced mixing ratios of gaseous HNO3, HCOOH, CH3COOH, and what appears to be (COOH)2. These aircraft-based samples were collected from a variety of fresh burning plumes and more aged haze layers from different source regions. Values of the enhancement factor, delta X/delta CO, where X represents an acidic gas, for combustion-impacted <span class="hlt">air</span> <span class="hlt">masses</span> sampled both near and farther away from the fires, were relatively uniform. However, comparison of carboxylic acid emission ratios measured in laboratory fires to field plume enhancement factors indicates significant in-plume production of HCOOH. Biomass-burning appears to be an important source of HNO3, HCOOH, and CH3COOH to the troposphere over subarctic Canada.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA636043','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA636043"><span>Environmental Assessment: Proposed Construction of Army and <span class="hlt">Air</span> Force <span class="hlt">Exchange</span> Service New Day Street Shoppette</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2003-10-01</p> <p>would either be operated by AAFES as a franchise or would be owned by AAFES. The three existing 10,000-gallon underground storage tanks (USTs...Street Shoppette FINAL Army and <span class="hlt">Air</span> Force <span class="hlt">Exchange</span> Service 2-3 The restaurant would either be operated by AAFES as a franchise or would be owned by...levels of employment with the inclusion of a new restaurant, (to be either a franchise or AAFES-owned), car wash, increased services of the Auto Pride</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010DSRII..57.1212L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010DSRII..57.1212L"><span>The flushing and <span class="hlt">exchange</span> of the South China Sea derived from salt and <span class="hlt">mass</span> conservation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Yang; Bye, John A. T.; You, Yuzhu; Bao, Xianwen; Wu, Dexing</p> <p>2010-07-01</p> <p>In this paper, we use two kinds of hydrographic data, historical cruise data, Array for Real-time Geostrophic Oceanography (Argo) float data, and atmospheric data to study the water <span class="hlt">exchange</span> between the South China Sea (SCS) and the Pacific Ocean through the Luzon Strait. The annual mean distributions of temperature and salinity at five different levels in the SCS and the adjacent Pacific Ocean are presented, which indicate the occurrence of active water <span class="hlt">exchange</span> through the Luzon Strait. The flushing and <span class="hlt">exchange</span> of the SCS are then determined by the application of salt and <span class="hlt">mass</span> conservation in a multi-layered thermohaline system, using an estimate of the net rainfall obtained from reanalysis data. The results show that the annual mean flushing time is 44±8 months with an inflow rate of 11±2 Sv (1 Sv=10 6 m 3 s -1), part of which recirculates at a deeper level through the Luzon Strait, the remainder (6±2 Sv) forming the SCS throughflow. The diffusive influx of salt is also estimated and accounts for about 10% of the total influx, and hence advection dominates over diffusion in the water <span class="hlt">exchange</span> through the Luzon Strait. The seasonal cycle of <span class="hlt">exchange</span> shows a maximum in autumn and winter of about twice the annual mean rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29627358','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29627358"><span>Hydrogen-deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry reveals folding and allostery in protein-protein interactions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ramirez-Sarmiento, Cesar A; Komives, Elizabeth A</p> <p>2018-04-06</p> <p>Hydrogen-deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDXMS) has emerged as a powerful approach for revealing folding and allostery in protein-protein interactions. The advent of higher resolution <span class="hlt">mass</span> spectrometers combined with ion mobility separation and ultra performance liquid chromatographic separations have allowed the complete coverage of large protein sequences and multi-protein complexes. Liquid-handling robots have improved the reproducibility and accurate temperature control of the sample preparation. Many researchers are also appreciating the power of combining biophysical approaches such as stopped-flow fluorescence, single molecule FRET, and molecular dynamics simulations with HDXMS. In this review, we focus on studies that have used a combination of approaches to reveal (re)folding of proteins as well as on long-distance allosteric changes upon interaction. Copyright © 2018 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000037970&hterms=gas+natural&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dgas%2Bnatural','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000037970&hterms=gas+natural&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dgas%2Bnatural"><span>The Effect of Rain on <span class="hlt">Air</span>-Water Gas <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ho, David T.; Bliven, Larry F.; Wanninkhof, Rik; Schlosser, Peter</p> <p>1997-01-01</p> <p>The relationship between gas transfer velocity and rain rate was investigated at NASA's Rain-Sea Interaction Facility (RSIF) using several SF, evasion experiments. During each experiment, a water tank below the rain simulator was supersaturated with SF6, a synthetic gas, and the gas transfer velocities were calculated from the measured decrease in SF6 concentration with time. The results from experiments with IS different rain rates (7 to 10 mm/h) and 1 of 2 drop sizes (2.8 or 4.2 mm diameter) confirm a significant and systematic enhancement of <span class="hlt">air</span>-water gas <span class="hlt">exchange</span> by rainfall. The gas transfer velocities derived from our experiment were related to the kinetic energy flux calculated from the rain rate and drop size. The relationship obtained for mono-dropsize rain at the RSIF was extrapolated to natural rain using the kinetic energy flux of natural rain calculated from the Marshall-Palmer raindrop size distribution. Results of laboratory experiments at RSIF were compared to field observations made during a tropical rainstorm in Miami, Florida and show good agreement between laboratory and field data.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.agu.org/journals/jc/v096/iC04/90JC02642/','USGSPUBS'); return false;" href="http://www.agu.org/journals/jc/v096/iC04/90JC02642/"><span>Atmospheric organochlorine pollutants and <span class="hlt">air</span>-sea <span class="hlt">exchange</span> of hexachlorocyclohexane in the Bering and Chukchi Seas</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hinckley, D.A.; Bidleman, T.F.; Rice, C.P.</p> <p>1991-01-01</p> <p>Organochlorine pesticides have been found in Arctic fish, marine mammals, birds, and plankton for some time. The lack of local sources and remoteness of the region imply long-range transport and deposition of contaminants into the Arctic from sources to the south. While on the third Soviet-American Joint Ecological Expedition to the Bering and Chukchi Seas (August 1988), high-volume <span class="hlt">air</span> samples were taken and analyzed for organochlorine pesticides. Hexachlorocyclohexane (HCH), hexachlorobenzene, polychlorinated camphenes, and chlordane (listed in order of abundance, highest to lowest) were quantified. The <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> of HCH was estimated at 18 stations during the cruise. Average alpha-HCH concentrations in concurrent atmosphere and surface water samples were 250 pg m-3 and 2.4 ng L-1, respectively, and average gamma-HCH concentrations were 68 pg m-3 in the atmosphere and 0.6 ng L-1 in surface water. Calculations based on experimentally derived Henry's law constants showed that the surface water was undersaturated with respect to the atmosphere at most stations (alpha-HCH, average 79% saturation; gamma-HCH, average 28% saturation). The flux for alpha-HCH ranged from -47 ng m-2 day-1 (sea to <span class="hlt">air</span>) to 122 ng m-2 d-1 (<span class="hlt">air</span> to sea) and averaged 25 ng m-2 d-1 <span class="hlt">air</span> to sea. All fluxes of gamma-HCH were from <span class="hlt">air</span> to sea, ranged from 17 to 54 ng m-2 d-1, and averaged 31 ng m-2 d-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024135','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024135"><span>Stable isotope composition of waters in the Great Basin, United States 1. <span class="hlt">Air-mass</span> trajectories</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Friedman, I.; Harris, J.M.; Smith, G.I.; Johnson, C.A.</p> <p>2002-01-01</p> <p>Isentropic trajectories, calculated using the NOAA/Climate Monitoring and Diagnostics Laboratory's isentropic transport model, were used to determine <span class="hlt">air</span>-parcel origins and the influence of <span class="hlt">air</span> <span class="hlt">mass</span> trajectories on the isotopic composition of precipitation events that occurred between October 1991 and September 1993 at Cedar City, Utah, and Winnemucca, Nevada. Examination of trajectories that trace the position of <span class="hlt">air</span> parcels backward in time for 10 days indicated five distinct regions of water vapor origin: (1) Gulf of Alaska and North Pacific, (2) central Pacific, (3) tropical Pacific, (4) Gulf of Mexico, and (5) continental land <span class="hlt">mass</span>. Deuterium (??D) and oxygen-18 (??18O) analyses were made of precipitation representing 99% of all Cedar City events. Similar analyses were made on precipitation representing 66% of the precipitation falling at Winnemucca during the same period. The average isotopic composition of precipitation derived from each water vapor source was determined. More than half of the precipitation that fell at both sites during the study period originated in the tropical Pacific and traveled northeast to the Great Basin; only a small proportion traversed the Sierra Nevada. The isotopic composition of precipitation is determined by <span class="hlt">air-mass</span> origin and its track to the collection station, mechanism of droplet formation, reequilibration within clouds, and evaporation during its passage from cloud to ground. The Rayleigh distillation model can explain the changes in isotopic composition of precipitation as an <span class="hlt">air</span> <span class="hlt">mass</span> is cooled pseudo-adiabatically during uplift. However, the complicated processes that take place in the rapidly convecting environment of cumulonimbus and other clouds that are common in the Great Basin, especially in summer, require modification of this model because raindrops that form in the lower portion of those clouds undergo isotopic change as they are elevated to upper levels of the clouds from where they eventually drop to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22923254','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22923254"><span>Effects of <span class="hlt">air</span> <span class="hlt">exchange</span> property of passive-type radon-thoron discriminative detectors on performance of radon and thoron measurements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Omori, Y; Janik, M; Sorimachi, A; Ishikawa, T; Tokonami, S</p> <p>2012-11-01</p> <p>Pairs of diffusion chambers with different <span class="hlt">air</span> <span class="hlt">exchange</span> rates are used in a large-scale survey to determine radon and thoron, separately. When they are enclosed in radon-proof bags for keeping after the exposure, since radon does not escape out immediately from the low-diffusion chamber, it leads to further exposure in the bags and disturbs the estimation of radon and thoron concentrations. In this study, the effects of the different <span class="hlt">air</span> <span class="hlt">exchange</span> properties of the radon-thoron discriminative detectors with CR-39 chips on the estimations of radon and thoron concentrations were investigated. The commercially available and frequently used detectors, Raduet, are examined in this study. The result shows that radon escapes out in 10 h. When degassing is not enough after the exposure in a calibration experiment or high-background radiation area, the residual radon causes the overestimation of the radon concentration and increase in the uncertainty in the thoron concentration, i.e. a low-performance quality of radon and thoron measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JASMS..26..564D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JASMS..26..564D"><span>Ion Mobility Spectrometry-Hydrogen Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry of Anions: Part 1. Peptides to Proteins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Donohoe, Gregory C.; Khakinejad, Mahdiar; Valentine, Stephen J.</p> <p>2015-04-01</p> <p>Ion mobility spectrometry (IMS) coupled with hydrogen deuterium <span class="hlt">exchange</span> (HDX)-<span class="hlt">mass</span> spectrometry (MS) has been used to study the conformations of negatively-charged peptide and protein ions. Results are presented for ion conformers of angiotensin 1, a synthetic peptide (SP), bovine insulin, ubiquitin, and equine cytochrome c. In general, the SP ion conformers demonstrate a greater level of HDX efficiency as a greater proportion of the sites undergo HDX. Additionally, these ions exhibit the fastest rates of <span class="hlt">exchange</span>. Comparatively, the angiotensin 1 ions exhibit a lower rate of <span class="hlt">exchange</span> and HDX level presumably because of decreased accessibility of <span class="hlt">exchange</span> sites by charge sites. The latter are likely confined to the peptide termini. Insulin ions show dramatically reduced HDX levels and <span class="hlt">exchange</span> rates, which can be attributed to decreased conformational flexibility resulting from the disulfide bonds. For the larger ubiquitin and protein ions, increased HDX is observed for larger ions of higher charge state. For ubiquitin, a conformational transition from compact to more elongated species (from lower to higher charge states) is reflected by an increase in HDX levels. These results can be explained by a combination of interior site protection by compact conformers as well as decreased access by charge sites. The elongated cytochrome c ions provide the largest HDX levels where higher values correlate with charge state. These results are consistent with increased <span class="hlt">exchange</span> site accessibility by additional charge sites. The data from these enhanced IMS-HDX experiments are described in terms of charge site location, conformer rigidity, and interior site protection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJP..132..245M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJP..132..245M"><span>Aerosol concentration measurements and correlations with <span class="hlt">air</span> <span class="hlt">mass</span> trajectories at the Pierre Auger Observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Micheletti, M. I.; Louedec, K.; Freire, M.; Vitale, P.; Piacentini, R. D.</p> <p>2017-06-01</p> <p>Aerosols play an important role in radiative transfer processes involved in different fields of study. In particular, their influence is crucial in the attenuation of light at astronomical and astrophysical observatories, and has to be taken into account in light transfer models employed to reconstruct the signals. The Andean Argentinean region is increasingly being considered as a good candidate to host such facilities, as well as the ones for solar-energy resources, and an adequate knowledge of aerosols characteristics there is needed, but it is not always possible due to the vast area involved and the scarce atmospheric data at ground. The aim of this work is to find correlations between aerosol data and particle trajectories that can give an insight into the origin and behaviour of aerosols in this zone and can be employed in situations in which one does not have local aerosol measurements. For this purpose, an aerosol spectrometer and dust monitor (Grimm 1.109) was installed at the Pierre Auger Observatory of ultra-high-energy cosmic rays, to record aerosol concentrations in different size intervals, at surface level. These measurements are analysed and correlated with <span class="hlt">air</span> <span class="hlt">mass</span> trajectories obtained from HYSPLIT (NOAA) model calculations. High aerosol concentrations are registered predominantly when <span class="hlt">air</span> <span class="hlt">masses</span> have travelled mostly over continental areas, mainly from the NE direction, while low aerosol concentrations are found in correspondence with <span class="hlt">air</span> <span class="hlt">masses</span> coming from the Pacific Ocean, from the NW direction. Different size distribution patterns were found for the aerosols depending on their origin: marine or continental. This work shows for the first time the size distribution of aerosols registered at the Pierre Auger Observatory. The correlations found between <span class="hlt">mass</span> and particle concentrations (total and for different size ranges) and HYSPLIT <span class="hlt">air</span> <span class="hlt">mass</span> trajectories, confirm that the latter can be employed as a useful tool to infer the sources, evolution</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.9230H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.9230H"><span>Spatial variability of hailfalls in France: an analysis of <span class="hlt">air</span> <span class="hlt">mass</span> retro-trajectories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hermida, Lucía; Merino, Andrés; Sánchez, José Luis; Berthet, Claude; Dessens, Jean; López, Laura; Fernández-González, Sergio; Gascón, Estíbaliz; García-Ortega, Eduardo</p> <p>2014-05-01</p> <p>Hail is the main meteorological risk in south-west France, with the strongest hailfalls being concentrated in just a few days. Specifically, this phenomenon occurs most often and with the greatest severity in the Midi-Pyrénées area. Previous studies have revealed the high spatial variability of hailfall in this part of France, even leading to different characteristics being recorded on hailpads that were relatively close together. For this reason, an analysis of the <span class="hlt">air</span> <span class="hlt">mass</span> trajectories was carried out at ground level and at altitude, which subsequently led to the formation of the hail recorded by these hailpads. It is already known that in the study zone, the trajectories of the storms usually stretch for long distances and are oriented towards the east, leading to hailstones with diameters in excess of 3 cm, and without any change in direction above 3 km. We analysed different days with hail precipitation where there was at least one stone with a diameter of 3 cm or larger. Using the simulations from these days, an analysis of the backward trajectories of the <span class="hlt">air</span> <span class="hlt">masses</span> was carried out. We used the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory Model) to determine the origin of the <span class="hlt">air</span> <span class="hlt">masses</span>, and tracked them toward each of the hailpads that were hit during the day studied. The height of the final points was the height of the impacted hailpads. Similarly, the backward trajectories for different heights were also established. Finally, the results show how storms that affect neighbouring hailpads come from very different <span class="hlt">air</span> <span class="hlt">masses</span>; and provide a deeper understanding of the high variability that affects the characteristics of hailfalls. Acknowledgements The authors would like to thank the Regional Government of Castile-León for its financial support through the project LE220A11-2. This study was supported by the following grants: GRANIMETRO (CGL2010-15930); MICROMETEO (IPT-310000-2010-22).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGeo...10.5793S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGeo...10.5793S"><span>Biology and <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> controls on the distribution of carbon isotope ratios (δ13C) in the ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmittner, A.; Gruber, N.; Mix, A. C.; Key, R. M.; Tagliabue, A.; Westberry, T. K.</p> <p>2013-09-01</p> <p>Analysis of observations and sensitivity experiments with a new three-dimensional global model of stable carbon isotope cycling elucidate processes that control the distribution of δ13C of dissolved inorganic carbon (DIC) in the contemporary and preindustrial ocean. Biological fractionation and the sinking of isotopically light δ13C organic matter from the surface into the interior ocean leads to low δ13CDIC values at depths and in high latitude surface waters and high values in the upper ocean at low latitudes with maxima in the subtropics. <span class="hlt">Air</span>-sea gas <span class="hlt">exchange</span> has two effects. First, it acts to reduce the spatial gradients created by biology. Second, the associated temperature-dependent fractionation tends to increase (decrease) δ13CDIC values of colder (warmer) water, which generates gradients that oppose those arising from biology. Our model results suggest that both effects are similarly important in influencing surface and interior δ13CDIC distributions. However, since <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> is slow in the modern ocean, the biological effect dominates spatial δ13CDIC gradients both in the interior and at the surface, in contrast to conclusions from some previous studies. Calcium carbonate cycling, pH dependency of fractionation during <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span>, and kinetic fractionation have minor effects on δ13CDIC. Accumulation of isotopically light carbon from anthropogenic fossil fuel burning has decreased the spatial variability of surface and deep δ13CDIC since the industrial revolution in our model simulations. Analysis of a new synthesis of δ13CDIC measurements from years 1990 to 2005 is used to quantify preformed and remineralized contributions as well as the effects of biology and <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span>. The model reproduces major features of the observed large-scale distribution of δ13CDIC as well as the individual contributions and effects. Residual misfits are documented and analyzed. Simulated surface and subsurface δ13CDIC are influenced by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810126C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810126C"><span>Towards constraining the stratosphere-troposphere <span class="hlt">exchange</span> of radiocarbon: strategies of stratospheric 14CO2 measurements using <span class="hlt">Air</span>Core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Huilin; Paul, Dipayan; Meijer, Harro; Miller, John; Kivi, Rigel; Krol, Maarten</p> <p>2016-04-01</p> <p>Radiocarbon (14C) plays an important role in the carbon cycle studies to understand both natural and anthropogenic carbon fluxes, but also in atmospheric chemistry to constrain hydroxyl radical (OH) concentrations in the atmosphere. Apart from the enormous 14C emissions from nuclear bomb testing in the 1950s and 1960s, radiocarbon is primarily produced in the stratosphere due to the cosmogenic production. To this end, better understanding the stratospheric radiocarbon source is very useful to advance the use of radiocarbon for these applications. However, stratospheric 14C observations have been very limited so that there are large uncertainties on the magnitude and the location of the 14C production as well as the transport of radiocarbon from the stratosphere to the troposphere. Recently we have successfully made stratospheric 14C measurements using <span class="hlt">Air</span>Core samples from Sodankylä, Northern Finland. <span class="hlt">Air</span>Core is an innovative atmospheric sampling system, which passively collects atmospheric <span class="hlt">air</span> samples into a long piece of coiled stainless steel tubing during the descent of a balloon flight. Due to the relatively low cost of the consumables, there is a potential to make such <span class="hlt">Air</span>Core profiling in other parts of the world on a regular basis. In this study, we simulate the 14C in the atmosphere and assess the stratosphere-troposphere <span class="hlt">exchange</span> of radiocarbon using the TM5 model. The Sodankylä radiocarbon measurements will be used to verify the performance of the model at high latitude. Besides this, we will also evaluate the influence of different cosmogenic 14C production scenarios and the uncertainties in the OH field on the seasonal cycles of radiocarbon and on the stratosphere-troposphere <span class="hlt">exchange</span>, and based on the results design a strategy to set up a 14C measurement program using <span class="hlt">Air</span>Core.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22103582','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22103582"><span>Distribution and <span class="hlt">air</span>-sea <span class="hlt">exchange</span> of current-use pesticides (CUPs) from East Asia to the high Arctic Ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhong, Guangcai; Xie, Zhiyong; Cai, Minghong; Möller, Axel; Sturm, Renate; Tang, Jianhui; Zhang, Gan; He, Jianfeng; Ebinghaus, Ralf</p> <p>2012-01-03</p> <p>Surface seawater and marine boundary layer <span class="hlt">air</span> samples were collected on the ice-breaker R/V Xuelong (Snow Dragon) from the East China Sea to the high Arctic (33.23-84.5° N) in July to September 2010 and have been analyzed for six current-use pesticides (CUPs): trifluralin, endosulfan, chlorothalonil, chlorpyrifos, dacthal, and dicofol. In all oceanic <span class="hlt">air</span> samples, the six CUPs were detected, showing highest level (>100 pg/m(3)) in the Sea of Japan. Gaseous CUPs basically decreased from East Asia (between 36.6 and 45.1° N) toward Bering and Chukchi Seas. The dissolved CUPs in ocean water ranged widely from <MDL to 111 pg/L. Latitudinal trends of α-endosulfan, chlorpyrifos, and dicofol in seawater were roughly consistent with their latitudinal trends in <span class="hlt">air</span>. Trifluralin in seawater was relatively high in the Sea of Japan (35.2° N) and evenly distributed between 36.9 and 72.5° N, but it remained below the detection limit at the highest northern latitudes in Chukchi Sea. In contrast with other CUPs, concentrations of chlorothalonil and dacthal were more abundant in Chukchi Sea and in East Asia. The <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> of CUPs was generally dominated by net deposition. Latitudinal trends of fugacity ratios of α-endosulfan, chlorothalonil, and dacthal showed stronger deposition of these compounds in East Asia than in Chukchi Sea, while trifluralin showed stronger deposition in Chukchi Sea (-455 ± 245 pg/m(2)/day) than in the North Pacific (-241 ± 158 pg/m(2)/day). <span class="hlt">Air</span>-sea gas <span class="hlt">exchange</span> of chlorpyrifos varied from net volatilizaiton in East Asia (<40° N) to equilibrium or net deposition in the North Pacific and the Arctic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28488200','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28488200"><span>Application of Atmospheric Pressure Photoionization H/D-<span class="hlt">exchange</span> <span class="hlt">Mass</span> Spectrometry for Speciation of Sulfur-containing Compounds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Acter, Thamina; Kim, Donghwi; Ahmed, Arif; Ha, Ji-Hyoung; Kim, Sunghwan</p> <p>2017-08-01</p> <p>Herein we report the observation of atmospheric pressure in-source hydrogen-deuterium <span class="hlt">exchange</span> (HDX) of thiol group for the first time. The HDX for thiol group was optimized for positive atmospheric pressure photoionization (APPI) <span class="hlt">mass</span> spectrometry (MS). The optimized HDX-MS was applied for 31 model compounds (thiols, thiophenes, and sulfides) to demonstrate that <span class="hlt">exchanged</span> peaks were observed only for thiols. The optimized method has been successfully applied to the isolated fractions of sulfur-rich oil samples. The <span class="hlt">exchange</span> of one and two thiol hydrogens with deuterium was observed in the thiol fraction; no HDX was observed in the other fractions. Thus, the results presented in this study demonstrate that the HDX-MS method using APPI ionization source can be effective for speciation of sulfur compounds. This method has the potential to be used to access corrosion problems caused by thiol-containing compounds. Graphical Abstract ᅟ.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24643387','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24643387"><span>Concentrations, atmospheric partitioning, and <span class="hlt">air</span>-water/soil surface <span class="hlt">exchange</span> of polychlorinated dibenzo-p-dioxin and dibenzofuran along the upper reaches of the Haihe River basin, North China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nie, Zhiqiang; Die, Qingqi; Yang, Yufei; Tang, Zhenwu; Wang, Qi; Huang, Qifei</p> <p>2014-01-01</p> <p>Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDF) were overall measured and compared in ambient <span class="hlt">air</span>, water, soils, and sediments along the upper reaches of the Haihe River of North China, so as to evaluate their concentrations, profiles, and to understand the processes of gas-particle partitioning and <span class="hlt">air</span>-water/soil <span class="hlt">exchange</span>. The following results were obtained: (1) The average concentrations (toxic equivalents, TEQs) of 2,3,7,8-PCDD/PCDF in <span class="hlt">air</span>, water, sediment, and soil samples were 4,855 fg/m(3), 9.5 pg/L, 99.2 pg/g dry weight (dw), and 56.4 pg/g (203 fg TEQ/m(3), 0.46 pg TEQ/L, 2.2 pg TEQ/g dw, and 1.3 pg TEQ/g, respectively), respectively. (2) Although OCDF, 1,2,3,4,6,7,8-HpCDF, OCDD, and 1,2,3,4,6,7,8-HpCDD were the dominant congeners among four environmental sinks, obvious discrepancies of these congener and homologue patterns of PCDD/PCDF were observed still. (3) Significant linear correlations for PCDD/PCDF were observed between the gas-particle partition coefficient (K p) and the subcooled liquid vapor pressure (P L (0)) and octanol-<span class="hlt">air</span> partition coefficient (K oa). (4) Fugacity fraction values of <span class="hlt">air</span>-water <span class="hlt">exchange</span> indicated that most of PCDD/PCDF homologues were dominated by net volatilization from water into <span class="hlt">air</span>. The low-chlorinated PCDD/PCDF (tetra- to hexa-) presented a strong net volatilization from the soil into <span class="hlt">air</span>, while high-chlorinated PCDD/PCDF (hepta- to octa-) were mainly close to equilibrium for <span class="hlt">air</span>-soil <span class="hlt">exchange</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17328184','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17328184"><span><span class="hlt">Air</span>-water <span class="hlt">exchange</span> and dry deposition of polybrominated diphenyl ethers at a coastal site in Izmir Bay, Turkey.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cetin, Banu; Odabasi, Mustafa</p> <p>2007-02-01</p> <p>The <span class="hlt">air</span>-water <span class="hlt">exchange</span> of polybrominated diphenyl ethers (PBDEs), an emerging class of persistent organic pollutants (POPs), was investigated using paired <span class="hlt">air</span>-water samples (n = 15) collected in July and December, 2005 from Guzelyali Port in Izmir Bay, Turkey. Total dissolved-phase water concentrations of PBDEs (sigma7PBDEs) were 212 +/- 65 and 87 +/- 57 pg L(-1) (average +/- SD) in summer and winter, respectively. BDE-209 was the most abundant congener in all samples, followed by BDE-99 and -47. Average ambient gas-phase sigma7PBDE concentrations were between 189 +/- 61 (summer) and 76 +/- 65 pg m(-3) (winter). Net <span class="hlt">air</span>-water <span class="hlt">exchange</span> fluxes ranged from -0.9 +/- 1.0 (BDE-28) (volatilization) to 11.1 +/- 5.4 (BDE-209) ng m(-2) day(-1) (deposition). The BDE-28 fluxes were mainly volatilization while the other congeners were deposited. Gas- and dissolved-phase concentrations were significantly correlated (P = 0.33-0.55, p < 0.05, except for BDE-209, r = 0.05, p > 0.05) indicating thatthe atmosphere controls the surface water PBDE levels in this coastal environment. Estimated particulate dry deposition fluxes ranged between 2.7 +/- 1.9 (BDE-154) and 116 +/- 84 ng m(-2) day(-1) (BDE-209) indicating that dry deposition is also a significant input to surface waters in the study area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMEP43D0770P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMEP43D0770P"><span>Wind driven vertical transport in a vegetated, wetland water column with <span class="hlt">air</span>-water gas <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poindexter, C.; Variano, E. A.</p> <p>2010-12-01</p> <p>Flow around arrays of cylinders at low and intermediate Reynolds numbers has been studied numerically, analytically and experimentally. Early results demonstrated that at flow around randomly oriented cylinders exhibits reduced turbulent length scales and reduced diffusivity when compared to similarly forced, unimpeded flows (Nepf 1999). While horizontal dispersion in flows through cylinder arrays has received considerable research attention, the case of vertical dispersion of reactive constituents has not. This case is relevant to the vertical transfer of dissolved gases in wetlands with emergent vegetation. We present results showing that the presence of vegetation can significantly enhance vertical transport, including gas transfer across the <span class="hlt">air</span>-water interface. Specifically, we study a wind-sheared <span class="hlt">air</span>-water interface in which randomly arrayed cylinders represent emergent vegetation. Wind is one of several processes that may govern physical dispersion of dissolved gases in wetlands. Wind represents the dominant force for gas transfer across the <span class="hlt">air</span>-water interface in the ocean. Empirical relationships between wind and the gas transfer coefficient, k, have been used to estimate spatial variability of CO2 <span class="hlt">exchange</span> across the worlds’ oceans. Because wetlands with emergent vegetation are different from oceans, different model of wind effects is needed. We investigated the vertical transport of dissolved oxygen in a scaled wetland model built inside a laboratory tank equipped with an open-ended wind tunnel. Plastic tubing immersed in water to a depth of approximately 40 cm represented emergent vegetation of cylindrical form such as hard-stem bulrush (Schoenoplectus acutus). After partially removing the oxygen from the tank water via reaction with sodium sulfite, we used an optical probe to measure dissolved oxygen at mid-depth as the tank water re-equilibrated with the <span class="hlt">air</span> above. We used dissolved oxygen time-series for a range of mean wind speeds to estimate the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20337424','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20337424"><span>Advantages of isotopic depletion of proteins for hydrogen/deuterium <span class="hlt">exchange</span> experiments monitored by <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bou-Assaf, George M; Chamoun, Jean E; Emmett, Mark R; Fajer, Piotr G; Marshall, Alan G</p> <p>2010-04-15</p> <p>Solution-phase hydrogen/deuterium <span class="hlt">exchange</span> (HDX) monitored by <span class="hlt">mass</span> spectrometry is an excellent tool to study protein-protein interactions and conformational changes in biological systems, especially when traditional methods such as X-ray crystallography or nuclear magnetic resonance are not feasible. Peak overlap among the dozens of proteolytic fragments (including those from autolysis of the protease) can be severe, due to high protein molecular weight(s) and the broad isotopic distributions due to multiple deuterations of many peptides. In addition, different subunits of a protein complex can yield isomeric proteolytic fragments. Here, we show that depletion of (13)C and/or (15)N for one or more protein subunits of a complex can greatly simplify the <span class="hlt">mass</span> spectra, increase the signal-to-noise ratio of the depleted fragment ions, and remove ambiguity in assignment of the m/z values to the correct isomeric peptides. Specifically, it becomes possible to monitor the <span class="hlt">exchange</span> progress for two isobaric fragments originating from two or more different subunits within the complex, without having to resort to tandem <span class="hlt">mass</span> spectrometry techniques that can lead to deuterium scrambling in the gas phase. Finally, because the isotopic distribution for a small to medium-size peptide is essentially just the monoisotopic species ((12)C(c)(1)H(h)(14)N(n)(16)O(o)(32)S(s)), it is not necessary to deconvolve the natural abundance distribution for each partially deuterated peptide during HDX data reduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28186210','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28186210"><span>US residential building <span class="hlt">air</span> <span class="hlt">exchange</span> rates: new perspectives to improve decision making at vapor intrusion sites.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reichman, Rivka; Shirazi, Elham; Colliver, Donald G; Pennell, Kelly G</p> <p>2017-02-22</p> <p>Vapor intrusion (VI) is well-known to be difficult to characterize because indoor <span class="hlt">air</span> (IA) concentrations exhibit considerable temporal and spatial variability in homes throughout impacted communities. To overcome this and other limitations, most VI science has focused on subsurface processes; however there is a need to understand the role of aboveground processes, especially building operation, in the context of VI exposure risks. This tutorial review focuses on building <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AERs) and provides a review of literature related building AERs to inform decision making at VI sites. Commonly referenced AER values used by VI regulators and practitioners do not account for the variability in AER values that have been published in indoor <span class="hlt">air</span> quality studies. The information presented herein highlights that seasonal differences, short-term weather conditions, home age and <span class="hlt">air</span> conditioning status, which are well known to influence AERs, are also likely to influence IA concentrations at VI sites. Results of a 3D VI model in combination with relevant AER values reveal that IA concentrations can vary more than one order of magnitude due to <span class="hlt">air</span> conditioning status and one order of magnitude due to house age. Collectively, the data presented strongly support the need to consider AERs when making decisions at VI sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28924306','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28924306"><span>Refrigerant Performance Evaluation Including Effects of Transport Properties and Optimized Heat <span class="hlt">Exchangers</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brignoli, Riccardo; Brown, J Steven; Skye, H; Domanski, Piotr A</p> <p>2017-08-01</p> <p>Preliminary refrigerant screenings typically rely on using cycle simulation models involving thermodynamic properties alone. This approach has two shortcomings. First, it neglects transport properties, whose influence on system performance is particularly strong through their impact on the performance of the heat <span class="hlt">exchangers</span>. Second, the refrigerant temperatures in the evaporator and condenser are specified as input, while real-life equipment operates at imposed heat sink and heat source temperatures; the temperatures in the evaporator and condensers are established based on overall heat transfer resistances of these heat <span class="hlt">exchangers</span> and the balance of the system. The paper discusses a simulation methodology and model that addresses the above shortcomings. This model simulates the thermodynamic cycle operating at specified heat sink and heat source temperature profiles, and includes the ability to account for the effects of thermophysical properties and refrigerant <span class="hlt">mass</span> flux on refrigerant heat transfer and pressure drop in the <span class="hlt">air</span>-to-refrigerant evaporator and condenser. Additionally, the model can optimize the refrigerant <span class="hlt">mass</span> flux in the heat <span class="hlt">exchangers</span> to maximize the Coefficient of Performance. The new model is validated with experimental data and its predictions are contrasted to those of a model based on thermodynamic properties alone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1150902-multi-scale-modeling-approximation-assisted-optimization-bare-tube-heat-exchangers','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1150902-multi-scale-modeling-approximation-assisted-optimization-bare-tube-heat-exchangers"><span>MULTI-SCALE MODELING AND APPROXIMATION ASSISTED OPTIMIZATION OF BARE TUBE HEAT <span class="hlt">EXCHANGERS</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bacellar, Daniel; Ling, Jiazhen; Aute, Vikrant</p> <p>2014-01-01</p> <p><span class="hlt">Air</span>-to-refrigerant heat <span class="hlt">exchangers</span> are very common in <span class="hlt">air</span>-conditioning, heat pump and refrigeration applications. In these heat <span class="hlt">exchangers</span>, there is a great benefit in terms of size, weight, refrigerant charge and heat transfer coefficient, by moving from conventional channel sizes (~ 9mm) to smaller channel sizes (< 5mm). This work investigates new designs for <span class="hlt">air</span>-to-refrigerant heat <span class="hlt">exchangers</span> with tube outer diameter ranging from 0.5 to 2.0mm. The goal of this research is to develop and optimize the design of these heat <span class="hlt">exchangers</span> and compare their performance with existing state of the art designs. The <span class="hlt">air</span>-side performance of various tube bundle configurationsmore » are analyzed using a Parallel Parameterized CFD (PPCFD) technique. PPCFD allows for fast-parametric CFD analyses of various geometries with topology change. Approximation techniques drastically reduce the number of CFD evaluations required during optimization. Maximum Entropy Design method is used for sampling and Kriging method is used for metamodeling. Metamodels are developed for the <span class="hlt">air</span>-side heat transfer coefficients and pressure drop as a function of tube-bundle dimensions and <span class="hlt">air</span> velocity. The metamodels are then integrated with an <span class="hlt">air</span>-to-refrigerant heat <span class="hlt">exchanger</span> design code. This integration allows a multi-scale analysis of <span class="hlt">air</span>-side performance heat <span class="hlt">exchangers</span> including <span class="hlt">air</span>-to-refrigerant heat transfer and phase change. Overall optimization is carried out using a multi-objective genetic algorithm. The optimal designs found can exhibit 50 percent size reduction, 75 percent decrease in <span class="hlt">air</span> side pressure drop and doubled <span class="hlt">air</span> heat transfer coefficients compared to a high performance compact micro channel heat <span class="hlt">exchanger</span> with same capacity and flow rates.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=pollution+AND+light&pg=5&id=EJ090046','ERIC'); return false;" href="https://eric.ed.gov/?q=pollution+AND+light&pg=5&id=EJ090046"><span>The Analysis of PPM Levels of Gases in <span class="hlt">Air</span> by Photoionization <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Driscoll, John N.; Warneck, Peter</p> <p>1973-01-01</p> <p>Discusses analysis of trace gases in <span class="hlt">air</span> by photoionization <span class="hlt">mass</span> spectrometer. It is shown that the necessary sensitivity can be obtained by eliminating the UV monochromator and using direct ionization with a hydrogen light source. (JP)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4294719','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4294719"><span>Experimental study of heat transfer and thermal performance with longitudinal fins of solar <span class="hlt">air</span> heater</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chabane, Foued; Moummi, Noureddine; Benramache, Said</p> <p>2013-01-01</p> <p>The thermal performance of a single pass solar <span class="hlt">air</span> heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat <span class="hlt">exchange</span> and render the flow fluid in the channel uniform. The effect of <span class="hlt">mass</span> flow rate of <span class="hlt">air</span> on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two <span class="hlt">air</span> <span class="hlt">mass</span> flow rates of 0.012 and 0.016 kg s−1. Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s−1 with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the <span class="hlt">mass</span> flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency. PMID:25685486</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25685486','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25685486"><span>Experimental study of heat transfer and thermal performance with longitudinal fins of solar <span class="hlt">air</span> heater.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chabane, Foued; Moummi, Noureddine; Benramache, Said</p> <p>2014-03-01</p> <p>The thermal performance of a single pass solar <span class="hlt">air</span> heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat <span class="hlt">exchange</span> and render the flow fluid in the channel uniform. The effect of <span class="hlt">mass</span> flow rate of <span class="hlt">air</span> on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two <span class="hlt">air</span> <span class="hlt">mass</span> flow rates of 0.012 and 0.016 kg s(-1). Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s(-1) with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the <span class="hlt">mass</span> flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=311934&Lab=NERL&keyword=simulation+AND+processes&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=311934&Lab=NERL&keyword=simulation+AND+processes&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Development and Evaluation of a New <span class="hlt">Air</span> <span class="hlt">Exchange</span> Rate Algorithm for the Stochastic Human Exposure and Dose Simulation Model (ISES Presentation)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Previous exposure assessment panel studies have observed considerable seasonal, between-home and between-city variability in residential pollutant infiltration. This is likely a result of differences in home ventilation, or <span class="hlt">air</span> <span class="hlt">exchange</span> rates (AER). The Stochastic Human Exposure ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130000766','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130000766"><span>International Space Station Common Cabin <span class="hlt">Air</span> Assembly Condensing Heat <span class="hlt">Exchanger</span> Hydrophilic Coating Operation, Recovery, and Lessons Learned</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Balistreri, Steven F.; Steele, John W.; Caron, Mark E.; Laliberte, Yvon J.; Shaw, Laura A.</p> <p>2013-01-01</p> <p>The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin <span class="hlt">air</span> is controlled by the Common Cabin <span class="hlt">Air</span> Assembly (CCAA). The CCAA consists of a fan, a condensing heat <span class="hlt">exchanger</span> (CHX), an <span class="hlt">air</span>/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent <span class="hlt">air</span>. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX in the ISS segments, the unit s ability to remove moisture from the <span class="hlt">air</span> is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the ISS cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings as well as remediation and recovery of the full heat <span class="hlt">exchanger</span> will be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..245e2027R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..245e2027R"><span>Cooperation of Horizontal Ground Heat <span class="hlt">Exchanger</span> with the Ventilation Unit During Summer - Case Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romańska-Zapała, Anna; Furtak, Marcin; Dechnik, Mirosław</p> <p>2017-10-01</p> <p>Renewable energy sources are used in the modern energy-efficient buildings to improve their energy balance. One of them is used in the mechanical ventilation system ground <span class="hlt">air</span> heat <span class="hlt">exchanger</span> (earth-<span class="hlt">air</span> heat <span class="hlt">exchanger</span> - EAHX). This solution, right after heat recovery from exhaust <span class="hlt">air</span> (recuperation), allows the reduction in the energy needed to obtain the desired temperature of supply <span class="hlt">air</span>. The article presents the results of "in situ" measurements of pipe ground <span class="hlt">air</span> heat <span class="hlt">exchanger</span> cooperating with the <span class="hlt">air</span> handling unit, supporting cooling the building in the summer season, in Polish climatic conditions. The laboratory consists of a ventilation unit intake - exhaust with rotor for which the source of fresh <span class="hlt">air</span> is the <span class="hlt">air</span> intake wall and two <span class="hlt">air</span> intakes field cooperating with the tube with ground <span class="hlt">air</span> heat <span class="hlt">exchangers</span>. Selection of the source of fresh <span class="hlt">air</span> is performed using sprocket with actuators. This system is part of the ventilation system of the Malopolska Laboratory of Energy-Efficient Building (MLBE) building of Cracow University of Technology. The measuring system are, among others, the sensors of parameters of <span class="hlt">air</span> inlets and outlets of the heat <span class="hlt">exchanger</span> channels EAHX and weather station that senses the local weather conditions. The measurement data are recorded and archived by the integrated process control system in the building of MLBE. During the study measurements of operating parameters of the ventilation unit cooperating with the selected source of fresh <span class="hlt">air</span> were performed. Two cases of operation of the system: using EAHX heat <span class="hlt">exchanger</span> and without it, were analyzed. Potentially the use of ground <span class="hlt">air</span> heat <span class="hlt">exchanger</span> in the mechanical ventilation system can reduce the energy demand for heating or cooling rooms by the pre-adjustment of the supply <span class="hlt">air</span> temperature. Considering the results can be concluded that the continuous use of these <span class="hlt">exchangers</span> is not optimal. This relationship is appropriate not only on an annual basis for the transitional periods (spring</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title47-vol2/pdf/CFR-2010-title47-vol2-sec22-880.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title47-vol2/pdf/CFR-2010-title47-vol2-sec22-880.pdf"><span>47 CFR 22.880 - Information <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES <span class="hlt">Air</span>-Ground Radiotelephone Service Commercial Aviation <span class="hlt">Air</span>-Ground Systems § 22.880 Information <span class="hlt">exchange</span>. (a) Prior notification. Public safety/CII licensees may notify a commercial aviation <span class="hlt">air</span>-ground system...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..126a2018A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..126a2018A"><span>Modification split type <span class="hlt">air</span> conditioning unit by installing internal heat <span class="hlt">exchanger</span> and condenser precooling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ambarita, H.</p> <p>2018-03-01</p> <p>In this paper, a modified of <span class="hlt">air</span> conditioning (AC) system is proposed. In the modified system, an internal heat <span class="hlt">exchanger</span> and condenser precooling unit are installed. The objective is to explore the effect of the additional equipment to the performance of the system. An AC with compressor power of 1 PK is modified and compared with the original one. The results show that ER of the modified system is higher than the original one in order of 3.6%. The work of the compressor of the modified system is 12.5% lower than work of the compressor without modification. Finally, the COP of the modified system is 11.71% higher than the original one. These facts reveal that the combination of IHX and condenser precooling shows positive impact on the performance of the AC. It is recommended to use the modified system to improve the energy efficiency of the <span class="hlt">Air</span> Conditioning system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960007722','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960007722"><span>Towards a theory of tropical/midlatitude <span class="hlt">mass</span> <span class="hlt">exchange</span> from the earth's surface through the stratosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hartley, Dana</p> <p>1995-01-01</p> <p>The main focus of this work is to understand the dynamics of <span class="hlt">mass</span> <span class="hlt">exchange</span> between the tropics and the midlatitudes and to determine any links between tropospheric <span class="hlt">exchange</span> and that in the stratosphere. We have approached this problem from two different perspectives. The first is aimed towards understanding the troposphere's role in inducing lower stratospheric tropical/midlatitude <span class="hlt">exchange</span>. For this project we focus on observational analysis of the lower stratosphere to assess the key regions of transport in/out of the tropics and to what extent this transport is driven by tropospheric processes. The second approach is to determine the extent to which stratospheric processes influence the troposphere. In this project we are performing potential vorticity (PV) inversions to assess the winds induced near the tropopause when the stratospheric polar vortex is displaced equatorward. These are each discussed in more detail in the subsections below. Also, we have organized a session on Tropical/Midlatitude Interaction and Transport at the Fall AGU where we will be showing our latest results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16023284','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16023284"><span>Local dynamics measured by hydrogen/deuterium <span class="hlt">exchange</span> and <span class="hlt">mass</span> spectrometry of creatine kinase digested by two proteases.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mazon, Hortense; Marcillat, Olivier; Forest, Eric; Vial, Christian</p> <p>2005-12-01</p> <p>Hydrogen/deuterium <span class="hlt">exchange</span> coupled to <span class="hlt">mass</span> spectrometry has been used to investigate the structure and dynamics of native dimeric cytosolic muscle creatine kinase. The protein was incubated in D2O for various time. After H/D <span class="hlt">exchange</span> and rapid quenching of the reaction, the partially deuterated protein was cleaved in parallel by two different proteases (pepsin or type XIII protease from Aspergillus saitoi) to increase the sequence coverage and spatial resolution of deuterium incorporation. The resulting peptides were analyzed by liquid chromatography coupled to <span class="hlt">mass</span> spectrometry. In comparison with the 3D structure of MM-CK, the analysis of the two independent proteolysis deuteration patterns allowed us to get new insights into CK local dynamics as compared to a previous study using pepsin [Mazon et al. Protein Science 13 (2004) 476-486]. In particular, we obtained more information on the kinetics and extent of deuterium <span class="hlt">exchange</span> in the N- and C-terminal extremities represented by the 1-22 and 362-380 pepsin peptides. Indeed, we observed a very different behaviour of the 1-12 and 13-22 type XIII protease peptides, and similarly for the 362-373 and 374-380 peptides. Moreover, comparison of the deuteration patterns of type XIII protease segments of the large 90-126 pepsin peptide led us to identify a small relatively dynamic region (108-114).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ACP....12.3761D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ACP....12.3761D"><span>Variability of aerosol, gaseous pollutants and meteorological characteristics associated with changes in <span class="hlt">air</span> <span class="hlt">mass</span> origin at the SW Atlantic coast of Iberia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diesch, J.-M.; Drewnick, F.; Zorn, S. R.; von der Weiden-Reinmüller, S.-L.; Martinez, M.; Borrmann, S.</p> <p>2012-04-01</p> <p>Measurements of the ambient aerosol were performed at the Southern coast of Spain, within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from 20 November until 9 December 2008 at the atmospheric research station "El Arenosillo" (37°5'47.76" N, 6°44'6.94" W). As the monitoring station is located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean, a variety of physical and chemical parameters of aerosols and gas phase could be characterized in dependency on the origin of <span class="hlt">air</span> <span class="hlt">masses</span>. Backwards trajectories were examined and compared with local meteorology to classify characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types for several source regions. Aerosol number and <span class="hlt">mass</span> as well as polycyclic aromatic hydrocarbons and black carbon concentrations were measured in PM1 and size distributions were registered covering a size range from 7 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol (NR-PM1) was measured by means of an Aerosol <span class="hlt">Mass</span> Spectrometer (Aerodyne HR-ToF-AMS). Gas phase analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) and a weather station provided meteorological parameters. Lowest average submicron particle <span class="hlt">mass</span> and number concentrations were found in <span class="hlt">air</span> <span class="hlt">masses</span> arriving from the Atlantic Ocean with values around 2 μg m-3 and 1000 cm-3. These <span class="hlt">mass</span> concentrations were about two to four times lower than the values recorded in <span class="hlt">air</span> <span class="hlt">masses</span> of continental and urban origins. For some species PM1-fractions in marine <span class="hlt">air</span> were significantly larger than in <span class="hlt">air</span> <span class="hlt">masses</span> originating from Huelva, a closely located city with extensive industrial activities. The largest fraction of sulfate (54%) was detected in marine <span class="hlt">air</span> <span class="hlt">masses</span> and was to a high degree not neutralized. In addition, small concentrations of methanesulfonic acid (MSA), a product of biogenic dimethyl sulfate (DMS) emissions, could be identified in the particle phase</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770003526','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770003526"><span>Lightweight Long Life Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, E. K.</p> <p>1976-01-01</p> <p>A shuttle orbiter flight configuration aluminum heat <span class="hlt">exchanger</span> was designed, fabricated, and tested. The heat <span class="hlt">exchanger</span> utilized aluminum clad titanium composite parting sheets for protection against parting sheet pin hole corrosion. The heat <span class="hlt">exchanger</span>, which is fully interchangeable with the shuttle condensing heat <span class="hlt">exchanger</span>, includes slurpers (a means for removing condensed water from the downstream face of the heat <span class="hlt">exchanger</span>), and both the core <span class="hlt">air</span> passes and slurpers were hydrophilic coated to enhance wettability. The test program included performance tests which demonstrated the adequacy of the design and confirmed the predicted weight savings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29058415','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29058415"><span>Online Simultaneous Hydrogen/Deuterium <span class="hlt">Exchange</span> of Multitarget Gas-Phase Molecules by Electrospray Ionization <span class="hlt">Mass</span> Spectrometry Coupled with Gas Chromatography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jeong, Eun Sook; Cha, Eunju; Cha, Sangwon; Kim, Sunghwan; Oh, Han Bin; Kwon, Oh-Seung; Lee, Jaeick</p> <p>2017-11-21</p> <p>In this study, a hydrogen/deuterium (H/D) <span class="hlt">exchange</span> method using gas chromatography-electrospray ionization/<span class="hlt">mass</span> spectrometry (GC-ESI/MS) was first investigated as a novel tool for online H/D <span class="hlt">exchange</span> of multitarget analytes. The GC and ESI source were combined with a homemade heated column transfer line. GC-ESI/MS-based H/D <span class="hlt">exchange</span> occurs in an atmospheric pressure ion source as a result of reacting the gas-phase analyte eluted from GC with charged droplets of deuterium oxide infused as the ESI spray solvent. The consumption of the deuterated solvent at a flow rate of 2 μL min -1 was more economical than that in online H/D <span class="hlt">exchange</span> methods reported to date. In-ESI-source H/D <span class="hlt">exchange</span> by GC-ESI/MS was applied to 11 stimulants with secondary amino or hydroxyl groups. After H/D <span class="hlt">exchange</span>, the spectra of the stimulants showed unexchanged, partially <span class="hlt">exchanged</span>, and fully <span class="hlt">exchanged</span> ions showing various degrees of <span class="hlt">exchange</span>. The relative abundances corrected for naturally occurring isotopes of the fully <span class="hlt">exchanged</span> ions of stimulants, except for etamivan, were in the range 24.3-85.5%. Methylephedrine and cyclazodone showed low H/D <span class="hlt">exchange</span> efficiency under acidic, neutral, and basic spray solvent conditions and nonexchange for etamivan with an acidic phenolic OH group. The in-ESI-source H/D <span class="hlt">exchange</span> efficiency by GC-ESI/MS was sufficient to determine the number of hydrogen by elucidation of fragmentation from the spectrum. Therefore, this online H/D <span class="hlt">exchange</span> technique using GC-ESI/MS has potential as an alternative method for simultaneous H/D <span class="hlt">exchange</span> of multitarget analytes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPS...218..286B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPS...218..286B"><span>Multi-layer membrane model for <span class="hlt">mass</span> transport in a direct ethanol fuel cell using an alkaline anion <span class="hlt">exchange</span> membrane</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bahrami, Hafez; Faghri, Amir</p> <p>2012-11-01</p> <p>A one-dimensional, isothermal, single-phase model is presented to investigate the <span class="hlt">mass</span> transport in a direct ethanol fuel cell incorporating an alkaline anion <span class="hlt">exchange</span> membrane. The electrochemistry is analytically solved and the closed-form solution is provided for two limiting cases assuming Tafel expressions for both oxygen reduction and ethanol oxidation. A multi-layer membrane model is proposed to properly account for the diffusive and electroosmotic transport of ethanol through the membrane. The fundamental differences in fuel crossover for positive and negative electroosmotic drag coefficients are discussed. It is found that ethanol crossover is significantly reduced upon using an alkaline anion <span class="hlt">exchange</span> membrane instead of a proton <span class="hlt">exchange</span> membrane, especially at current densities higher than 500 A m</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140008761','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140008761"><span>A Comparison of the Red Green Blue (RGB) <span class="hlt">Air</span> <span class="hlt">Mass</span> Imagery and Hyperspectral Infrared Retrieved Profiles and NOAA G-IV Dropsondes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berndt, Emily; Folmer, Michael; Dunion, Jason</p> <p>2014-01-01</p> <p>RGB <span class="hlt">air</span> <span class="hlt">mass</span> imagery is derived from multiple channels or paired channel differences. The combination of channels and channel differences means the resulting imagery does not represent a quantity or physical parameter such as brightness temperature in conventional single channel imagery. Without a specific quantity to reference, forecasters are often confused as to what RGB products represent. Hyperspectral infrared retrieved profiles and NOAA G-IV dropsondes provide insight about the vertical structure of the <span class="hlt">air</span> <span class="hlt">mass</span> represented on the RGB <span class="hlt">air</span> <span class="hlt">mass</span> imagery and are a first step to validating the imagery.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ThApC.110..423C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ThApC.110..423C"><span>On the origin and destination of atmospheric moisture and <span class="hlt">air</span> <span class="hlt">mass</span> over the Tibetan Plateau</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Bin; Xu, Xiang-De; Yang, Shuai; Zhang, Wei</p> <p>2012-12-01</p> <p>The Tibet Plateau (TP) is a key region that imposes profound impacts on the atmospheric water cycle and energy budget of Asia, even the global climate. In this work, we develop a climatology of origin (destination) of <span class="hlt">air</span> <span class="hlt">mass</span> and moisture transported to (from) the TP using a Lagrangian moisture diagnosis combined with the forward and backward atmospheric tracking schemes. The climatology is derived from 6-h particle positions based on 5-year (2005-2009) seasonal summer trajectory dataset from the Lagrangian particle dispersion model FLEXPART using NCEP/GFS data as input, where the regional model atmosphere was globally filled with particles. The results show that (1) the dominant origin of the moisture supplied to the TP is a narrow tropical-subtropical band in the extended Arabian Sea covering a long distance from the Indian subcontinent to the Southern Hemisphere. Two additional moisture sources are located in the northwestern part of TP and the Bay of Bengal and play a secondary role. This result indicates that the moisture transporting to the TP more depends on the Indian summer monsoon controlled by large-scale circulation. (2) The moisture departing from the TP can be transported rapidly to East Asia, including East China, Korea, Japan, and even East Pacific. The qualitative similarity between the regions of diagnosed moisture loss and the pattern of the observed precipitation highlights the robustness of the role of the TP on precipitation over East Asia. (3) In contrast to the moisture origin confined in the low level, the origin and fate of whole column <span class="hlt">air</span> <span class="hlt">mass</span> over the TP is largely controlled by a strong high-level Asian anticyclone. The results show that the TP is a crossroad of <span class="hlt">air</span> <span class="hlt">mass</span> where <span class="hlt">air</span> enters mainly from the northwest and northeast and continues in two separate streams: one goes southwestwards over the Indian Ocean and the other southeastwards through western North Pacific. Both of them partly enter the trade wind zone, which manifests the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSEC54B1327H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSEC54B1327H"><span>First System-Wide Estimates of <span class="hlt">Air</span>-Sea <span class="hlt">Exchange</span> of Carbon Dioxide in the Chesapeake Bay</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herrmann, M.; Najjar, R.; Menendez, A.</p> <p>2016-02-01</p> <p>Estuaries are estimated to play a major role in the global carbon cycle by degassing between 0.25 and 0.4 Pg C y-1, comparable to the uptake of atmospheric CO2 by continental shelf waters and as much as one quarter of the uptake of atmospheric CO2 by the open ocean. However, the global estimates of estuarine CO2 gas <span class="hlt">exchange</span> are highly uncertain mostly due to limited data availability and extreme heterogeneity of coastal systems. Notably, the <span class="hlt">air</span>-water CO2 flux for the largest U.S. estuary, the Chesapeake Bay, is yet unknown. Here we provide first system-level CO2 gas <span class="hlt">exchange</span> estimates for the Chesapeake Bay, using data from the Chesapeake Bay Water Quality Monitoring Program (CBWQMP) and other data sources. We focus on the main stem of the Chesapeake Bay; hence, tributaries, such as the tidal portions of the Potomac and James Rivers, are not included in this first estimation of the flux. The preliminary results show the Bay to be a net source of CO2 to the atmosphere, outgassing on average 0.2 Tg C yr-1 over the study period, between 1985 and 2013. The spatial and temporal variability of the gas <span class="hlt">exchange</span> will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28372725','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28372725"><span>Analysis of volatile compounds by open-<span class="hlt">air</span> ionization <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meher, Anil Kumar; Chen, Yu-Chie</p> <p>2017-05-08</p> <p>This study demonstrates a simple method for rapid and in situ identification of volatile and endogenous compounds in culinary spice samples through <span class="hlt">mass</span> spectrometry (MS). This method only requires a holder for solid spice sample (2-3 mm) that is placed close to a <span class="hlt">mass</span> spectrometer inlet, which is applied with a high voltage. Volatile species responsible for the aroma of the spice samples can be readily detected by the <span class="hlt">mass</span> spectrometer. Sample pretreatment is not required prior to MS analysis, and no solvent was used during MS analysis. The high voltage applied to the inlet of the <span class="hlt">mass</span> spectrometer induces the ionization of volatile compounds released from the solid spice samples. Furthermore, moisture in the <span class="hlt">air</span> also contributes to the ionization of volatile compounds. Dried spices including cinnamon and cloves are used as the model sample to demonstrate this straightforward MS analysis, which can be completed within few seconds. Furthermore, we also demonstrate the suitability of the current method for rapid screening of cinnamon quality through detection of the presence of a hepatotoxic agent, i.e. coumarin. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22894100','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22894100"><span>Measurement of <span class="hlt">air</span> <span class="hlt">exchange</span> rates in different indoor environments using continuous CO2 sensors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>You, Yan; Niu, Can; Zhou, Jian; Liu, Yating; Bai, Zhipeng; Zhang, Jiefeng; He, Fei; Zhang, Nan</p> <p>2012-01-01</p> <p>A new <span class="hlt">air</span> <span class="hlt">exchange</span> rate (AER) monitoring method using continuous CO2 sensors was developed and validated through both laboratory experiments and field studies. Controlled laboratory simulation tests were conducted in a 1-m3 environmental chamber at different AERs (0.1-10.0 hr(-1)). AERs were determined using the decay method based on box model assumptions. Field tests were conducted in classrooms, dormitories, meeting rooms and apartments during 2-5 weekdays using CO2 sensors coupled with data loggers. Indoor temperature, relative humidity (RH), and CO2 concentrations were continuously monitored while outdoor parameters combined with on-site climate conditions were recorded. Statistical results indicated that good laboratory performance was achieved: duplicate precision was within 10%, and the measured AERs were 90%-120% of the real AERs. Average AERs were 1.22, 1.37, 1.10, 1.91 and 0.73 hr(-1) in dormitories, <span class="hlt">air</span>-conditioned classrooms, classrooms with an <span class="hlt">air</span> circulation cooling system, reading rooms, and meeting rooms, respectively. In an elderly particulate matter exposure study, all the homes had AER values ranging from 0.29 to 3.46 hr(-1) in fall, and 0.12 to 1.39 hr(-1) in winter with a median AER of 1.15.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PalOc..31..582T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PalOc..31..582T"><span>Plio-Pleistocene evolution of water <span class="hlt">mass</span> <span class="hlt">exchange</span> and erosional input at the Atlantic-Arctic gateway</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Teschner, Claudia; Frank, Martin; Haley, Brian A.; Knies, Jochen</p> <p>2016-05-01</p> <p>Water <span class="hlt">mass</span> <span class="hlt">exchange</span> between the Arctic Ocean and the Norwegian-Greenland Seas has played an important role for the Atlantic thermohaline circulation and Northern Hemisphere climate. We reconstruct past water <span class="hlt">mass</span> mixing and erosional inputs from the radiogenic isotope compositions of neodymium (Nd), lead (Pb), and strontium (Sr) at Ocean Drilling Program site 911 (leg 151) from 906 m water depth on Yermak Plateau in the Fram Strait over the past 5.2 Myr. The isotopic compositions of past bottom waters were extracted from authigenic oxyhydroxide coatings of the bulk sediments. Neodymium isotope signatures obtained from surface sediments agree well with present-day deepwater ɛNd signature of -11.0 ± 0.2. Prior to 2.7 Ma the Nd and Pb isotope compositions of the bottom waters only show small variations indicative of a consistent influence of Atlantic waters. Since the major intensification of the Northern Hemisphere Glaciation at 2.7 Ma the seawater Nd isotope composition has varied more pronouncedly due to changes in weathering inputs related to the waxing and waning of the ice sheets on Svalbard, the Barents Sea, and the Eurasian shelf, due to changes in water <span class="hlt">mass</span> <span class="hlt">exchange</span> and due to the increasing supply of ice-rafted debris (IRD) originating from the Arctic Ocean. The seawater Pb isotope record also exhibits a higher short-term variability after 2.7 Ma, but there is also a trend toward more radiogenic values, which reflects a combination of changes in input sources and enhanced incongruent weathering inputs of Pb released from freshly eroded old continental rocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16615688','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16615688"><span>Testing of heat <span class="hlt">exchangers</span> in membrane oxygenators using <span class="hlt">air</span> pressure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hamilton, Carole; Stein, Jutta; Seidler, Rainer; Kind, Robert; Beck, Karin; Tosok, Jürgen; Upterfofel, Jörg</p> <p>2006-03-01</p> <p>All heat <span class="hlt">exchangers</span> (HE) in membrane oxygenators are tested by the manufacturer for water leaks during the production phase. However, for safety reasons, it is highly recommended that HEs be tested again before clinical use. The most common method is to attach the heater-cooler to the HE and allow the water to recirculate for at least 10 min, during which time a water leak should be evident. To improve the detection of water leaks, a test was devised using a pressure manometer with an integrated bulb used to pressurize the HE with <span class="hlt">air</span>. The cardiopulmonary bypass system is set up as per protocol. A pressure manometer adapted to a 1/2" tubing is connected to the water inlet side of the oxygenator. The water outlet side is blocked with a short piece of 1/2" deadend tubing. The HE is pressurized with 250 mmHg for at least 30 sec and observed for any drop. Over the last 2 years, only one oxygenator has been detected with a water leak in which the <span class="hlt">air</span>-method leaktest was performed. This unit was sent back to the manufacturer who confirmed the failure. Even though the incidence of water leaks is very low, it does occur and it is, therefore, important that all HEs are tested before they are used clinically. This method of using a pressure manometer offers many advantages, as the HE can be tested outside of the operating room (OR), allowing earlier testing of the oxygenator, no water contact is necessary, and it is simple, easy and quick to perform.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=68872&keyword=water+AND+gas+AND+exchange&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=68872&keyword=water+AND+gas+AND+exchange&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>DIFFUSIVE <span class="hlt">EXCHANGE</span> OF GASEOUS POLYCYCLIC AROMATIC HYDROCARBONS AND POLYCHLORINATED BIPHENYLS ACROSS THE <span class="hlt">AIR</span>-WATER INTERFACE OF THE CHESAPEAKE BAY. (R825245)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Dissolved and gas-phase concentrations of nine polycyclic aromatic hydrocarbons and 46 polychlorinated biphenyl congeners were measured at eight sites on the Chesapeake Bay at four different times of the year to estimate net diffusive <span class="hlt">air</span>-water gas <span class="hlt">exchange</span> rates. Gaseous PAHs ar...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ACPD...1227927E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ACPD...1227927E"><span><span class="hlt">Air</span>-surface <span class="hlt">exchange</span> measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Edwards, G. C.; Howard, D. A.</p> <p>2012-10-01</p> <p>This paper presents the first gaseous elemental mercury (GEM) <span class="hlt">air</span>-surface <span class="hlt">exchange</span> measurements obtained over naturally enriched and background (< 0.1 μg g-1 Hg) terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m-2 h-1 to 113 ± 6 ng m-2 h-1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m-2 h-1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. Comparison of the Australian data to North American data confirmed the need for Australian specific mercury <span class="hlt">air</span>-surface <span class="hlt">exchange</span> data representative of Australia's unique climatic conditions, vegetation types, land use patterns, and soils.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23336325','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23336325"><span>Indoor <span class="hlt">air</span> quality, <span class="hlt">air</span> <span class="hlt">exchange</span> rates, and radioactivity in new built temporary houses following the Great East Japan Earthquake in Minamisoma, Fukushima.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shinohara, N; Tokumura, M; Kazama, M; Yoshino, H; Ochiai, S; Mizukoshi, A</p> <p>2013-08-01</p> <p>This study measured <span class="hlt">air</span> <span class="hlt">exchange</span> rates, indoor concentrations of aldehydes and volatile organic compounds (VOCs), and radioactivity levels at 19 temporary houses in different temporary housing estate constructed in Minamisoma City following the Great East Japan Earthquake. The 19 surveyed houses represented all of the companies assigned to construct temporary houses in that Minamisoma City. Data were collected shortly after construction and before occupation, from August 2011 to January 2012. Mean <span class="hlt">air</span> <span class="hlt">exchange</span> rates in the temporary houses were 0.28/h, with no variation according to housing types and construction date. Mean indoor concentrations of formaldehyde, acetaldehyde, toluene, ethylbenzene, m/p-xylene, o-xylene, styrene, p-dichlorobenzene, tetradecane, and total VOCs (TVOCs) were 29.2, 72.7, 14.6, 6.35, 3.05, 1.81, 7.29, 14.3, 8.32, and 901 μg/m(3), respectively. The levels of acetaldehyde and TVOCs exceeded the indoor guideline (48 μg/m(3)) and interim target (400 μg/m(3)) in more than half of the 31 rooms tested. In addition to guideline chemicals, terpenes (α-pinene and d-limonene) and acetic esters (butyl acetate and ethyl acetate) were often detected in these houses. The indoor radiation levels measured by a Geiger-Müller tube (Mean: 0.22 μSv/h) were lower than those recorded outdoors (Mean: 0.42 μSv/h), although the shielding effect of the houses was less than for other types of buildings. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8338613','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8338613"><span>[The effect of the ventilation rate on <span class="hlt">air</span> particle and <span class="hlt">air</span> microbe concentration in operating rooms with conventional ventilation. 1. Measurement without surgical activity].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kruppa, B; Rüden, H</p> <p>1993-05-01</p> <p>The question was if a reduction of airborne particles and bacteria in conventionally (turbulently), ventilated operating theatres in comparison to Laminar-Airflow (LAF) operating theatres does occur at high <span class="hlt">air-exchange</span>-rates. Within the framework of energy consumption measures the influence of <span class="hlt">air-exchange</span>-rates on airborne particle and bacteria concentrations was determined in two identical operating theatres with conventional ventilation (wall diffusor panel) at the <span class="hlt">air-exchange</span>-rates 7.5, 10, 15 and 20/h without surgical activity. This was established by means of the statistical procedure of analysis of variance. Especially for the comparison of the <span class="hlt">air-exchange</span>-rates 7.5 and 15/h statistical differences were found for airborne particle concentrations in supply and ambient <span class="hlt">air</span>. Concerning airborne bacteria concentrations no differences were found among the various <span class="hlt">air-exchange</span>-rates. Explanation of variance is quite high for non-viable particles (supply <span class="hlt">air</span>: 37%, ambient <span class="hlt">air</span>: 81%) but negligible for viable particles (bacteria) with values below 15%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21069949','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21069949"><span>Predicting residential <span class="hlt">air</span> <span class="hlt">exchange</span> rates from questionnaires and meteorology: model evaluation in central North Carolina.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Breen, Michael S; Breen, Miyuki; Williams, Ronald W; Schultz, Bradley D</p> <p>2010-12-15</p> <p>A critical aspect of <span class="hlt">air</span> pollution exposure models is the estimation of the <span class="hlt">air</span> <span class="hlt">exchange</span> rate (AER) of individual homes, where people spend most of their time. The AER, which is the airflow into and out of a building, is a primary mechanism for entry of outdoor <span class="hlt">air</span> pollutants and removal of indoor source emissions. The mechanistic Lawrence Berkeley Laboratory (LBL) AER model was linked to a leakage area model to predict AER from questionnaires and meteorology. The LBL model was also extended to include natural ventilation (LBLX). Using literature-reported parameter values, AER predictions from LBL and LBLX models were compared to data from 642 daily AER measurements across 31 detached homes in central North Carolina, with corresponding questionnaires and meteorological observations. Data was collected on seven consecutive days during each of four consecutive seasons. For the individual model-predicted and measured AER, the median absolute difference was 43% (0.17 h(-1)) and 40% (0.17 h(-1)) for the LBL and LBLX models, respectively. Additionally, a literature-reported empirical scale factor (SF) AER model was evaluated, which showed a median absolute difference of 50% (0.25 h(-1)). The capability of the LBL, LBLX, and SF models could help reduce the AER uncertainty in <span class="hlt">air</span> pollution exposure models used to develop exposure metrics for health studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17874769','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17874769"><span><span class="hlt">Air</span>-sea <span class="hlt">exchange</span> fluxes of synthetic polycyclic musks in the North Sea and the Arctic.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xie, Zhiyong; Ebinghaus, Ralf; Temme, Christian; Heemken, Olaf; Ruck, Wolfgang</p> <p>2007-08-15</p> <p>Synthetic polycyclic musk fragrances Galaxolide (HHCB) and Tonalide (AHTN) were measured simultaneously in <span class="hlt">air</span> and seawater in the Arctic and the North Sea and in the rural <span class="hlt">air</span> of northern Germany. Median concentrations of gas-phase HHCB and AHTN were 4 and 18 pg m(-3) in the Arctic, 28 and 18 pg m(-3) in the North Sea, and 71 and 21 pg m(-3) in northern Germany, respectively. Various ratios of HHCB/AHTN implied that HHCB is quickly removed by atmospheric degradation, while AHTN is relatively persistent in the atmosphere. Dissolved concentrations ranged from 12 to 2030 pg L(-1) for HHCB and from below the method detection limit (3 pg L(-1)) to 965 pg L(-1) for AHTN with median values of 59 and 23 pg L(-1), respectively. The medians of volatilization fluxes for HHCB and AHTN were 27.2 and 14.2 ng m(-2) day(-1) and the depositional fluxes were 5.9 and 3.3 ng m(-2) day(-1), respectively, indicating water-to-<span class="hlt">air</span> volatilization is a significant process to eliminate HHCB and AHTN from the North Sea. In the Arctic, deposition fluxes dominated the <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> of HHCB and AHTN, suggesting atmospheric input controls the levels of HHCB and AHTN in the polar region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ACPD...1131585D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACPD...1131585D"><span>Variability of aerosol, gaseous pollutants and meteorological characteristics associated with continental, urban and marine <span class="hlt">air</span> <span class="hlt">masses</span> at the SW Atlantic coast of Iberia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diesch, J.-M.; Drewnick, F.; Zorn, S. R.; von der Weiden-Reinmüller, S.-L.; Martinez, M.; Borrmann, S.</p> <p>2011-12-01</p> <p>Measurements of the ambient aerosol were performed at the Southern coast of Spain, within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from 20 November until 9 December 2008 at the atmospheric research station "El Arenosillo" (37°5'47.76" N, 6°44'6.94" W). As the monitoring station is located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean a variety of physical and chemical parameters of aerosols and gas phase could be characterized in dependency on the origin of <span class="hlt">air</span> <span class="hlt">masses</span>. Backwards trajectories were examined and compared with local meteorology to classify characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types for several source regions. Aerosol number and <span class="hlt">mass</span> as well as polycyclic aromatic hydrocarbons and black carbon concentrations were measured in PM1 and size distributions were registered covering a size range from 7 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol <span class="hlt">Mass</span> Spectrometer (Aerodyne HR-ToF-AMS). Gas phase analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) and a weather station provided meteorological parameters. Lowest average submicron particle <span class="hlt">mass</span> and number concentrations were found in <span class="hlt">air</span> <span class="hlt">masses</span> arriving from the Atlantic Ocean with values around 2 μg m-3 and 1000 cm-3. These <span class="hlt">mass</span> concentrations were about two to four times lower than the values recorded in <span class="hlt">air</span> <span class="hlt">masses</span> of continental and urban origins. For some species PM1-fractions in marine <span class="hlt">air</span> were significantly larger than in <span class="hlt">air</span> <span class="hlt">masses</span> originating from Huelva, a closely located city with extensive industrial activities. The largest fraction of sulfate (54%) was detected in marine <span class="hlt">air</span> <span class="hlt">masses</span> and was to a high degree not neutralized. In addition small concentrations of methanesulfonic acid (MSA), a product of biogenic dimethyl sulfate (DMS) emissions could be identified in the particle phase. In all</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=20677','PESTICIDES'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=20677"><span>VOLATILIZATION RATES FROM WATER TO INDOOR <span class="hlt">AIR</span> ...</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Contaminated water can lead to volatilization of chemicals to residential indoor <span class="hlt">air</span>. Previous research has focused on only one source (shower stalls) and has been limited to chemicals in which gas-phase resistance to <span class="hlt">mass</span> transfer is of marginal significance. As a result, attempts to extrapolate chemical emissions from high-volatility chemicals to lower volatility chemicals, or to sources other than showers, have been difficult or impossible. This study involved the development of two-phase, dynamic <span class="hlt">mass</span> balance models for estimating chemical emissions from washing machines, dishwashers, and bathtubs. An existing model was adopted for showers only. Each model required the use of source- and chemical-specific <span class="hlt">mass</span> transfer coefficients. <span class="hlt">Air</span> <span class="hlt">exchange</span> (ventilation) rates were required for dishwashers and washing machines as well. These parameters were estimated based on a series of 113 experiments involving 5 tracer chemicals (acetone, ethyl acetate, toluene, ethylbenzene, and cyclohexane) and 4 sources (showers, bathtubs, washing machines, and dishwashers). Each set of experiments led to the determination of chemical stripping efficiencies and <span class="hlt">mass</span> transfer coefficients (overall, liquid-phase, gas-phase), and to an assessment of the importance of gas- phase resistance to <span class="hlt">mass</span> transfer. Stripping efficiencies ranged from 6.3% to 80% for showers, 2.6% to 69% for bathtubs, 18% to 100% for dishwashers, and 3.8% to 100% for washing machines. Acetone and cyclohexane al</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915393F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915393F"><span>Southeast Atlantic Cloud Properties in a Multivariate Statistical Model - How Relevant is <span class="hlt">Air</span> <span class="hlt">Mass</span> History for Local Cloud Properties?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuchs, Julia; Cermak, Jan; Andersen, Hendrik</p> <p>2017-04-01</p> <p>This study aims at untangling the impacts of external dynamics and local conditions on cloud properties in the Southeast Atlantic (SEA) by combining satellite and reanalysis data using multivariate statistics. The understanding of clouds and their determinants at different scales is important for constraining the Earth's radiative budget, and thus prominent in climate-system research. In this study, SEA stratocumulus cloud properties are observed not only as the result of local environmental conditions but also as affected by external dynamics and spatial origins of <span class="hlt">air</span> <span class="hlt">masses</span> entering the study area. In order to assess to what extent cloud properties are impacted by aerosol concentration, <span class="hlt">air</span> <span class="hlt">mass</span> history, and meteorology, a multivariate approach is conducted using satellite observations of aerosol and cloud properties (MODIS, SEVIRI), information on aerosol species composition (MACC) and meteorological context (ERA-Interim reanalysis). To account for the often-neglected but important role of <span class="hlt">air</span> <span class="hlt">mass</span> origin, information on <span class="hlt">air</span> <span class="hlt">mass</span> history based on HYSPLIT modeling is included in the statistical model. This multivariate approach is intended to lead to a better understanding of the physical processes behind observed stratocumulus cloud properties in the SEA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29501890','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29501890"><span>Distribution, sources, and <span class="hlt">air</span>-soil <span class="hlt">exchange</span> of OCPs, PCBs and PAHs in urban soils of Nepal.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pokhrel, Balram; Gong, Ping; Wang, Xiaoping; Chen, Mengke; Wang, Chuanfei; Gao, Shaopeng</p> <p>2018-06-01</p> <p>Due to the high temperature and extensive use of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), tropical cities could act as secondary sources of these pollutants and therefore received global concern. As compared with other tropical cities, studies on the <span class="hlt">air</span>-soil <span class="hlt">exchange</span> of OCPs, PCBs and PAHs in tropical Nepali cities remained limited. In the present study, 39 soil samples from Kathmandu (capital of Nepal) and 21 soil samples from Pokhara (second largest city in Nepal) were collected The soil concentrations of the sum of endosulfans (α- and β-endosulfans) ranged from 0.01 to 16.4 ng/g dw. Meanwhile, ∑dichlorodiphenyltrichloroethane (DDTs) ranged from 0.01 to 6.5 ng/g dw; ∑6PCBs from 0.01 to 9.7 ng/g dw; and ∑15PAHs from 17.1 to 6219 ng/g dw. High concentrations of OCPs were found in the soil of commercial land, while, high soil PAH concentrations were found on tourist/religious and commercial land. Combined the published <span class="hlt">air</span> concentrations, and the soil data of this study, the directions and fluxes of <span class="hlt">air</span>-soil <span class="hlt">exchange</span> were estimated using a fugacity model. It is clear that Nepal is a country contributing prominently to secondary emissions of endosulfans, hexachlorobenzene (HCB), and low molecular weight (LMW) PCBs and PAHs. The flux for all the pollutants in Kathmandu, with ∑endosulfans up to 3553; HCB up to 5263; and ∑LMW-PAHs up to 24378 ng m -2 h -1 , were higher than those in Pokhara. These high flux values indicated the high strength of Nepali soils to act as a source. Copyright © 2018 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/351688-sensing-flux-volatile-chemicals-through-air-water-interface','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/351688-sensing-flux-volatile-chemicals-through-air-water-interface"><span>Sensing the flux of volatile chemicals through the <span class="hlt">air</span>-water interface</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Mackay, D.; Schroeder, W.H.; Ooijen, H. von</p> <p>1997-12-31</p> <p>There are several situations in which there is a need to assess the direction and magnitude of the flux across the <span class="hlt">air</span>-water interface. Contaminants may be evaporating or absorbing in wastewater treatment systems in natural lake, river, estuarine and marine systems, and any attempt to compile a <span class="hlt">mass</span> balance must include this process. In this study the authors review the theory underlying <span class="hlt">air</span>-water <span class="hlt">exchange</span>, then describe and discuss a sparging approach by which the direction and magnitude of the flux can be ascertained. The principle of the method is that a known flow rate of <span class="hlt">air</span> is bubbled through themore » sparger and allowed to equilibrate with the water. The gas exiting the water surface is passed through a sorbent trap and later analyzed. The concentration, and hence the fugacity, of the contaminant in the sparged <span class="hlt">air</span> can be deduced. In parallel, a similar flow of <span class="hlt">air</span> from the atmosphere above the water is drawn through another sparger at a similar flow rate for a similar time and the trapped chemical analyzed giving the concentration and fugacity in the <span class="hlt">air</span>. These data show the direction of <span class="hlt">air</span>-water <span class="hlt">exchange</span> (i.e. from high to low fugacity) and with information on the <span class="hlt">mass</span> transfer coefficients and area, the flux. Successful tests were conducted of the system in a laboratory tank, in Lake Ontario and in Hamilton Harbour. Analyses of the traps showed a large number of peaks on the chromatogram many of which are believed to be of petroleum origin from fuels and vessel exhaust. The system will perform best under conditions where concentrations of specific contaminants are large, as occurs in waste water treatment systems. The approach has the potential to contribute to more accurate assessment of <span class="hlt">air</span>-water fluxes. It avoids the problems of different analytical methodologies and the effect of sorption in the water column.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AtmEn.129..229S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AtmEn.129..229S"><span>New directions: Time for a new approach to modeling surface-atmosphere <span class="hlt">exchanges</span> in <span class="hlt">air</span> quality models?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saylor, Rick D.; Hicks, Bruce B.</p> <p>2016-03-01</p> <p>Just as the <span class="hlt">exchange</span> of heat, moisture and momentum between the Earth's surface and the atmosphere are critical components of meteorological and climate models, the surface-atmosphere <span class="hlt">exchange</span> of many trace gases and aerosol particles is a vitally important process in <span class="hlt">air</span> quality (AQ) models. Current state-of-the-art AQ models treat the emission and deposition of most gases and particles as separate model parameterizations, even though evidence has accumulated over time that the emission and deposition processes of many constituents are often two sides of the same coin, with the upward (emission) or downward (deposition) flux over a landscape depending on a range of environmental, seasonal and biological variables. In this note we argue that the time has come to integrate the treatment of these processes in AQ models to provide biological, physical and chemical consistency and improved predictions of trace gases and particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989saei.confQ....C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989saei.confQ....C"><span>Analytical methods to predict liquid congealing in ram <span class="hlt">air</span> heat <span class="hlt">exchangers</span> during cold operation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coleman, Kenneth; Kosson, Robert</p> <p>1989-07-01</p> <p>Ram <span class="hlt">air</span> heat <span class="hlt">exchangers</span> used to cool liquids such as lube oils or Ethylene-Glycol/water solutions can be subject to congealing in very cold ambients, resulting in a loss of cooling capability. Two-dimensional, transient analytical models have been developed to explore this phenomenon with both continuous and staggered fin cores. Staggered fin predictions are compared to flight test data from the E-2C Allison T56 engine lube oil system during winter conditions. For simpler calculations, a viscosity ratio correction was introduced and found to provide reasonable cold ambient performance predictions for the staggered fin core, using a one-dimensional approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.A41B0028A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.A41B0028A"><span>Ozone Modulation/Membrane Introduction <span class="hlt">Mass</span> Spectrometry for Analysis of Hydrocarbon Pollutants in <span class="hlt">Air</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Atkinson, D. B.</p> <p>2001-12-01</p> <p>Modulation of volatile hydrocarbons in two-component mixtures is demonstrated using an ozonolysis pretreatment with membrane introduction <span class="hlt">mass</span> spectrometry (MIMS). The MIMS technique allows selective introduction of volatile and semivolatile analytes into a <span class="hlt">mass</span> spectrometer via processes known collectively as pervaporation [Kotiaho and Cooks, 1992]. A semipermeable polymer membrane acts as an interface between the sample (vapor or solution) and the vacuum of the <span class="hlt">mass</span> spectrometer. This technique has been demonstrated to allow for sensitive analysis of hydrocarbons and other non-polar volatile organic compounds (VOC`s) in <span class="hlt">air</span> samples[Cisper et al., 1995] . The methodology has the advantages of no sample pretreatment and short analysis time, which are promising for online monitoring applications but the chief disadvantage of lack of a separation step for the different analytes in a mixture. Several approaches have been investigated to overcome this problem including use of selective chemical ionization [Bier and Cooks, 1987] and multivariate calibration techniques[Ketola et al., 1999] . A new approach is reported for the quantitative measurement of VOCs in complex matrices. The method seeks to reduce the complexity of <span class="hlt">mass</span> spectra observed in hydrocarbon mixture analysis by selective pretreatment of the analyte mixture. In the current investigation, the rapid reaction of ozone with alkenes is used, producing oxygenated compounds which are suppressed by the MIMS system. This has the effect of removing signals due to unsaturated analytes from the compound <span class="hlt">mass</span> spectra, and comparison of the spectra before and after the ozone treatment reveals the nature of the parent compounds. In preliminary investigations, ozone reacted completely with cyclohexene from a mixture of cylohexene and cyclohexane, and with β -pinene from a mixture of toluene and β -pinene, suppressing the ion signals from the olefins. A slight attenuation of the cyclohexane and toluene in those</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996ApOpt..35.4905M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996ApOpt..35.4905M"><span>Diode laser-based <span class="hlt">air</span> <span class="hlt">mass</span> flux sensor for subsonic aeropropulsion inlets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, Michael F.; Kessler, William J.; Allen, Mark G.</p> <p>1996-08-01</p> <p>An optical <span class="hlt">air</span> <span class="hlt">mass</span> flux sensor based on a compact, room-temperature diode laser in a fiber-coupled delivery system has been tested on a full-scale gas turbine engine. The sensor is based on simultaneous measurements of O 2 density and Doppler-shifted velocity along a line of sight across the inlet duct. Extensive tests spanning engine power levels from idle to full afterburner demonstrate accuracy and precision of the order of 1 2 of full scale in density, velocity, and <span class="hlt">mass</span> flux. The precision-limited velocity at atmospheric pressure was as low as 40 cm s. Multiple data-reduction procedures are quantitatively compared to suggest optimal strategies for flight sensor packages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmEn.122..628S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmEn.122..628S"><span>Measuring and modeling <span class="hlt">air</span> <span class="hlt">exchange</span> rates inside taxi cabs in Los Angeles, California</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shu, Shi; Yu, Nu; Wang, Yueyan; Zhu, Yifang</p> <p>2015-12-01</p> <p><span class="hlt">Air</span> <span class="hlt">exchange</span> rates (AERs) have a direct impact on traffic-related <span class="hlt">air</span> pollutant (TRAP) levels inside vehicles. Taxi drivers are occupationally exposed to TRAP on a daily basis, yet there is limited measurement of AERs in taxi cabs. To fill this gap, AERs were quantified in 22 representative Los Angeles taxi cabs including 10 Prius, 5 Crown Victoria, 3 Camry, 3 Caravan, and 1 Uplander under realistic driving (RD) conditions. To further study the impacts of window position and ventilation settings on taxi AERs, additional tests were conducted on 14 taxis with windows closed (WC) and on the other 8 taxis with not only windows closed but also medium fan speed (WC-MFS) under outdoor <span class="hlt">air</span> mode. Under RD conditions, the AERs in all 22 cabs had a mean of 63 h-1 with a median of 38 h-1. Similar AERs were observed under WC condition when compared to those measured under RD condition. Under WC-MFS condition, AERs were significantly increased in all taxi cabs, when compared with those measured under RD condition. A General Estimating Equation (GEE) model was developed and the modeling results showed that vehicle model was a significant factor in determining the AERs in taxi cabs under RD condition. Driving speed and car age were positively associated with AERs but not statistically significant. Overall, AERs measured in taxi cabs were much higher than typical AERs people usually encounter in indoor environments such as homes, offices, and even regular passenger vehicles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol11/pdf/CFR-2011-title40-vol11-sec63-1435.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol11/pdf/CFR-2011-title40-vol11-sec63-1435.pdf"><span>40 CFR 63.1435 - Heat <span class="hlt">exchanger</span> provisions.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Heat <span class="hlt">exchanger</span> provisions. 63.1435... Standards for Hazardous <span class="hlt">Air</span> Pollutant Emissions for Polyether Polyols Production § 63.1435 Heat <span class="hlt">exchanger</span>... for heat <span class="hlt">exchange</span> systems, with the exceptions noted in paragraphs (b) through (e) of this section. (b...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol11/pdf/CFR-2010-title40-vol11-sec63-1435.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol11/pdf/CFR-2010-title40-vol11-sec63-1435.pdf"><span>40 CFR 63.1435 - Heat <span class="hlt">exchanger</span> provisions.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Heat <span class="hlt">exchanger</span> provisions. 63.1435... Standards for Hazardous <span class="hlt">Air</span> Pollutant Emissions for Polyether Polyols Production § 63.1435 Heat <span class="hlt">exchanger</span>... for heat <span class="hlt">exchange</span> systems, with the exceptions noted in paragraphs (b) through (e) of this section. (b...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JTePh..60.1549K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JTePh..60.1549K"><span>Small-size <span class="hlt">mass</span> spectrometer for determining gases and volatile compounds in <span class="hlt">air</span> during breathing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kogan, V. T.; Kozlenok, A. V.; Chichagov, Yu. V.; Antonov, A. S.; Lebedev, D. S.; Bogdanov, A. A.; Moroshkin, V. S.; Berezina, A. V.; Viktorova-Leclerc, O. S.; Vlasov, S. A.; Tubol'tsev, Yu. V.</p> <p>2015-10-01</p> <p>We describe an automated <span class="hlt">mass</span> spectrometer for diagnostics of deceases from the composition of exhaled <span class="hlt">air</span>. It includes a capillary system, which performs a rapid direct feeding of the sample to the instrument without changing substantially its composition and serves for studying the dynamics of variation of the ratio between various components of exhaled <span class="hlt">air</span>. The membrane system for introducing the sample is intended for determining low concentrations of volatile organic compounds which are biomarkers of pathologies. It is characterized by selective transmittance and ensures the detection limits of target compounds at the parts per million-parts per billion (ppm-ppb) level. A static <span class="hlt">mass</span> analyzer operating on permanent magnets possesses advantages important for mobile devices as compared to its dynamic analogs: it is more reliable in operation, has a larger dynamic range, and can be used for determining the concentration of components in the mixture one-by-one or simultaneously. The curvilinear output boundary of the magnetic lens of the <span class="hlt">mass</span> analyzer makes it possible to reduce its weight and size by 2.5 times without deteriorating the <span class="hlt">mass</span> resolution. We report on the results of testing of the instrument and consider the possibility of its application for early detection of deceases of respiratory and blood circulation system, gastrointestinal tract, and endocrine system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26589062','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26589062"><span>Molecular Dynamics Simulations Provide Atomistic Insight into Hydrogen <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry Experiments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Petruk, Ariel A; Defelipe, Lucas A; Rodríguez Limardo, Ramiro G; Bucci, Hernán; Marti, Marcelo A; Turjanski, Adrian G</p> <p>2013-01-08</p> <p>It is now clear that proteins are flexible entities that in solution switch between conformations to achieve their function. Hydrogen/Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry (HX/MS) is an invaluable tool to understand dynamic changes in proteins modulated by cofactor binding, post-transductional modifications, or protein-protein interactions. ERK2MAPK, a protein involved in highly conserved signal transduction pathways of paramount importance for normal cellular function, has been extensively studied by HX/MS. Experiments of the ERK2MAPK in the inactive and active states (in the presence or absence of bound ATP) have provided valuable information on the plasticity of the MAPK domain. However, interpretation of the HX/MS data is difficult, and changes are mostly explained in relation to available X-ray structures, precluding a complete atomic picture of protein dynamics. In the present work, we have used all atom Molecular Dynamics simulations (MD) to provide a theoretical framework for the interpretation of HX/MS data. Our results show that detailed analysis of protein-solvent interaction along the MD simulations allows (i) prediction of the number of protons <span class="hlt">exchanged</span> for each peptide in the HX/MS experiments, (ii) rationalization of the experimentally observed changes in <span class="hlt">exchange</span> rates in different protein conditions at the residue level, and (iii) that at least for ERK2MAPK, most of the functionally observed differences in protein dynamics are related to what can be considered the native state conformational ensemble. In summary, the combination of HX/MS experiments with all atom MD simulations emerges as a powerful approach to study protein native state dynamics with atomic resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12732918','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12732918"><span>Uncertainty evaluation of <span class="hlt">mass</span> values determined by electronic balances in analytical chemistry: a new method to correct for <span class="hlt">air</span> buoyancy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wunderli, S; Fortunato, G; Reichmuth, A; Richard, Ph</p> <p>2003-06-01</p> <p>A new method to correct for the largest systematic influence in <span class="hlt">mass</span> determination-<span class="hlt">air</span> buoyancy-is outlined. A full description of the most relevant influence parameters is given and the combined measurement uncertainty is evaluated according to the ISO-GUM approach [1]. A new correction method for <span class="hlt">air</span> buoyancy using an artefact is presented. This method has the advantage that only a <span class="hlt">mass</span> artefact is used to correct for <span class="hlt">air</span> buoyancy. The classical approach demands the determination of the <span class="hlt">air</span> density and therefore suitable equipment to measure at least the <span class="hlt">air</span> temperature, the <span class="hlt">air</span> pressure and the relative <span class="hlt">air</span> humidity within the demanded uncertainties (i.e. three independent measurement tasks have to be performed simultaneously). The calculated uncertainty is lower for the classical method. However a field laboratory may not always be in possession of fully traceable measurement systems for these room climatic parameters.A comparison of three approaches applied to the calculation of the combined uncertainty of <span class="hlt">mass</span> values is presented. Namely the classical determination of <span class="hlt">air</span> buoyancy, the artefact method, and the neglecting of this systematic effect as proposed in the new EURACHEM/CITAC guide [2]. The artefact method is suitable for high-precision measurement in analytical chemistry and especially for the production of certified reference materials, reference values and analytical chemical reference materials. The method could also be used either for volume determination of solids or for <span class="hlt">air</span> density measurement by an independent method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=176545&keyword=Detection+AND+ammonium&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=176545&keyword=Detection+AND+ammonium&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>AUTOMATED DECONVOLUTION OF COMPOSITE <span class="hlt">MASS</span> SPECTRA OBTAINED WITH AN OPEN-<span class="hlt">AIR</span> IONIZATIONS SOURCE BASED ON EXACT <span class="hlt">MASSES</span> AND RELATIVE ISOTIPIC ABUNDANCES</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Chemicals dispersed by accidental, deliberate, or weather-related events must be rapidly identified to assess health risks. <span class="hlt">Mass</span> spectra from high levels of analytes obtained using rapid, open-<span class="hlt">air</span> ionization by a Direct Analysis in Real Time (DART®) ion source often contain<br><b...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70194076','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70194076"><span>Updated polychlorinated biphenyl <span class="hlt">mass</span> budget for Lake Michigan</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Guo, Jiehong; Romanak, Kevin; Westenbroek, Stephen M.; Li, An; Kreis, Russell; Hites, Ronald A.; Venier, Marta</p> <p>2017-01-01</p> <p>This study revisits and updates the Lake Michigan <span class="hlt">Mass</span> Balance Project (LMMBP) for polychlorinated biphenyls (PCBs) that was conducted in 1994–1995. This work uses recent concentrations of PCBs in tributary and open lake water, <span class="hlt">air</span>, and sediment to calculate an updated <span class="hlt">mass</span> budget. Five of the 11 LMMBP tributaries were revisited in 2015. In these five tributaries, the geometric mean concentrations of ∑PCBs (sum of 85 congeners) ranged from 1.52 to 22.4 ng L–1. The highest concentrations of PCBs were generally found in the Lower Fox River and in the Indiana Harbor and Ship Canal. The input flows of ∑PCBs from wet deposition, dry deposition, tributary loading, and <span class="hlt">air</span> to water <span class="hlt">exchange</span>, and the output flows due to sediment burial, volatilization from water to <span class="hlt">air</span>, and transport to Lake Huron and through the Chicago Diversion were calculated, as well as flows related to the internal processes of settling, resuspension, and sediment–water diffusion. The net transfer of ∑PCBs is 1240 ± 531 kg yr–1 out of the lake. This net transfer is 46% lower than that estimated in 1994–1995. PCB concentrations in most matrices in the lake are decreasing, which drove the decline of all the individual input and output flows. Atmospheric deposition has become negligible, while volatilization from the water surface is still a major route of loss, releasing PCBs from the lake into the <span class="hlt">air</span>. Large <span class="hlt">masses</span> of PCBs remain in the water column and surface sediments and are likely to contribute to the future efflux of PCBs from the lake to the <span class="hlt">air</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1240194','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1240194"><span>Ozone and limonene in indoor <span class="hlt">air</span>: a source of submicron particle exposure.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wainman, T; Zhang, J; Weschler, C J; Lioy, P J</p> <p>2000-01-01</p> <p>Little information currently exists regarding the occurrence of secondary organic aerosol formation in indoor <span class="hlt">air</span>. Smog chamber studies have demonstrated that high aerosol yields result from the reaction of ozone with terpenes, both of which commonly occur in indoor <span class="hlt">air</span>. However, smog chambers are typically static systems, whereas indoor environments are dynamic. We conducted a series of experiments to investigate the potential for secondary aerosol in indoor <span class="hlt">air</span> as a result of the reaction of ozone with d-limonene, a compound commonly used in <span class="hlt">air</span> fresheners. A dynamic chamber design was used in which a smaller chamber was nested inside a larger one, with <span class="hlt">air</span> <span class="hlt">exchange</span> occurring between the two. The inner chamber was used to represent a model indoor environment and was operated at an <span class="hlt">air</span> <span class="hlt">exchange</span> rate below 1 <span class="hlt">exchange</span>/hr, while the outer chamber was operated at a high <span class="hlt">air</span> <span class="hlt">exchange</span> rate of approximately 45 <span class="hlt">exchanges</span>/hr. Limonene was introduced into the inner chamber either by the evaporation of reagent-grade d-limonene or by inserting a lemon-scented, solid <span class="hlt">air</span> freshener. A series of ozone injections were made into the inner chamber during the course of each experiment, and an optical particle counter was used to measure the particle concentration. Measurable particle formation and growth occurred almost exclusively in the 0.1-0.2 microm and 0.2-0.3 microm size fractions in all of the experiments. Particle formation in the 0.1-0.2 microm size range occurred as soon as ozone was introduced, but the formation of particles in the 0.2-0.3 microm size range did not occur until at least the second ozone injection occurred. The results of this study show a clear potential for significant particle concentrations to be produced in indoor environments as a result of secondary particle formation via the ozone-limonene reaction. Because people spend the majority of their time indoors, secondary particles formed in indoor environments may make a significant contribution to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11133393','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11133393"><span>Ozone and limonene in indoor <span class="hlt">air</span>: a source of submicron particle exposure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wainman, T; Zhang, J; Weschler, C J; Lioy, P J</p> <p>2000-12-01</p> <p>Little information currently exists regarding the occurrence of secondary organic aerosol formation in indoor <span class="hlt">air</span>. Smog chamber studies have demonstrated that high aerosol yields result from the reaction of ozone with terpenes, both of which commonly occur in indoor <span class="hlt">air</span>. However, smog chambers are typically static systems, whereas indoor environments are dynamic. We conducted a series of experiments to investigate the potential for secondary aerosol in indoor <span class="hlt">air</span> as a result of the reaction of ozone with d-limonene, a compound commonly used in <span class="hlt">air</span> fresheners. A dynamic chamber design was used in which a smaller chamber was nested inside a larger one, with <span class="hlt">air</span> <span class="hlt">exchange</span> occurring between the two. The inner chamber was used to represent a model indoor environment and was operated at an <span class="hlt">air</span> <span class="hlt">exchange</span> rate below 1 <span class="hlt">exchange</span>/hr, while the outer chamber was operated at a high <span class="hlt">air</span> <span class="hlt">exchange</span> rate of approximately 45 <span class="hlt">exchanges</span>/hr. Limonene was introduced into the inner chamber either by the evaporation of reagent-grade d-limonene or by inserting a lemon-scented, solid <span class="hlt">air</span> freshener. A series of ozone injections were made into the inner chamber during the course of each experiment, and an optical particle counter was used to measure the particle concentration. Measurable particle formation and growth occurred almost exclusively in the 0.1-0.2 microm and 0.2-0.3 microm size fractions in all of the experiments. Particle formation in the 0.1-0.2 microm size range occurred as soon as ozone was introduced, but the formation of particles in the 0.2-0.3 microm size range did not occur until at least the second ozone injection occurred. The results of this study show a clear potential for significant particle concentrations to be produced in indoor environments as a result of secondary particle formation via the ozone-limonene reaction. Because people spend the majority of their time indoors, secondary particles formed in indoor environments may make a significant contribution to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PhFl...17j0616J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhFl...17j0616J"><span>Boundary-layer <span class="hlt">exchange</span> by bubble: A novel method for generating transient nanofluidic layers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jennissen, Herbert P.</p> <p>2005-10-01</p> <p>Unstirred layers (i.e., Nernst boundary layers) occur on every dynamic solid-liquid interface, constituting a diffusion barrier, since the velocity of a moving liquid approaches zero at the surface (no slip). If a macromolecule-surface reaction rate is higher than the diffusion rate, the Nernst layer is solute depleted and the reaction rate becomes <span class="hlt">mass</span>-transport limited. The thickness of a Nernst boundary layer (δN) generally lies between 5 and 50μm. In an evanescent wave rheometer, measuring fibrinogen adsorption to fused silica, we made the fundamental observation that an <span class="hlt">air</span> bubble preceding the sample through the flow cell abolishes the <span class="hlt">mass</span>-transport limitation of the Nernst diffusion layer. Instead exponential kinetics are found. Experimental and simulation studies strongly indicate that these results are due to the elimination of the Nernst diffusion layer and its replacement by a dynamic nanofluidic layer (δν) maximally 200-300nm thick. It is suggested that the <span class="hlt">air</span> bubble leads to a transient boundary-layer separation into a novel nanoboundary layer on the surface and the bulk fluid velocity profile separated by a vortex sheet with an estimated lifetime of 30-60s. A bubble-induced boundary-layer <span class="hlt">exchange</span> from the Nernst to the nanoboundary layer and back is obtained, giving sufficient time for the measurement of unbiased exponential surface kinetics. Noteworthy is that the nanolayer can exist at all and displays properties such as (i) a long persistence and resistance to dissipation by the bulk liquid (boundary-layer-<span class="hlt">exchange</span>-hysteresis) and (ii) a lack of solute depletion in spite of boundary-layer separation. The boundary-layer-<span class="hlt">exchange</span> by bubble (BLEB) method therefore appears ideal for enhancing the rates of all types of diffusion-limited macromolecular reactions on surfaces with contact angles between 0° and 90° and only appears limited by slippage due to nanobubbles or an <span class="hlt">air</span> gap beneath the nanofluidic layer on very hydrophobic surfaces. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26975003','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26975003"><span><span class="hlt">Air</span>-sea <span class="hlt">exchange</span> of gaseous mercury in the East China Sea.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Chunjie; Ci, Zhijia; Wang, Zhangwei; Zhang, Xiaoshan</p> <p>2016-05-01</p> <p>Two oceanographic cruises were carried out in the East China Sea (ECS) during the summer and fall of 2013. The main objectives of this study are to identify the spatial-temporal distributions of gaseous elemental mercury (GEM) in <span class="hlt">air</span> and dissolved gaseous mercury (DGM) in surface seawater, and then to estimate the Hg(0) flux. The GEM concentration was lower in summer (1.61 ± 0.32 ng m(-3)) than in fall (2.20 ± 0.58 ng m(-3)). The back-trajectory analysis revealed that the <span class="hlt">air</span> <span class="hlt">masses</span> with high GEM levels during fall largely originated from the land, while the <span class="hlt">air</span> <span class="hlt">masses</span> with low GEM levels during summer primarily originated from ocean. The spatial distribution patterns of total Hg (THg), fluorescence, and turbidity were consistent with the pattern of DGM with high levels in the nearshore area and low levels in the open sea. Additionally, the levels of percentage of DGM to THg (%DGM) were higher in the open sea than in the nearshore area, which was consistent with the previous studies. The THg concentration in fall was higher (1.47 ± 0.51 ng l(-1)) than those of other open oceans. The DGM concentration (60.1 ± 17.6 pg l(-1)) and Hg(0) flux (4.6 ± 3.6 ng m(-2) h(-1)) in summer were higher than those in fall (DGM: 49.6 ± 12.5 pg l(-1) and Hg(0) flux: 3.6 ± 2.8 ng m(-2) h(-1)). The emission flux of Hg(0) from the ECS was estimated to be 27.6 tons yr(-1), accounting for ∼0.98% of the global Hg oceanic evasion though the ECS only accounts for ∼0.21% of global ocean area, indicating that the ECS plays an important role in the oceanic Hg cycle. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DSRI..122...17M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DSRI..122...17M"><span>The <span class="hlt">air</span>-sea <span class="hlt">exchange</span> of mercury in the low latitude Pacific and Atlantic Oceans</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mason, Robert P.; Hammerschmidt, Chad R.; Lamborg, Carl H.; Bowman, Katlin L.; Swarr, Gretchen J.; Shelley, Rachel U.</p> <p>2017-04-01</p> <p><span class="hlt">Air</span>-sea <span class="hlt">exchange</span> is an important component of the global mercury (Hg) cycle as it mediates the rate of increase in ocean Hg, and therefore the rate of change in levels of methylmercury (MeHg), the most toxic and bioaccumulative form of Hg in seafood and the driver of human health concerns. Gas evasion of elemental Hg (Hg0) from the ocean is an important sink for ocean Hg with previous studies suggesting that evasion is not uniform across ocean basins. To understand further the factors controlling Hg0 evasion, and its relationship to atmospheric Hg deposition, we made measurements of dissolved Hg0 (DHg0) in surface waters, along with measurements of Hg in precipitation and on aerosols, and Hg0 in marine <span class="hlt">air</span>, during two GEOTRACES cruises; GP16 in the equatorial South Pacific and GA03 in the North Atlantic. We contrast the concentrations and estimated evasion fluxes of Hg0 during these cruises, and the factors influencing this <span class="hlt">exchange</span>. Concentrations of DHg0 and fluxes were lower during the GP16 cruise than during the GA03 cruise, and likely reflect the lower atmospheric deposition in the South Pacific. An examination of Hg/Al ratios for aerosols from the cruises suggests that they were anthropogenically-enriched relative to crustal material, although to a lesser degree for the South Pacific than the aerosols over the North Atlantic. Both regions appear to be net sources of Hg0 to the atmosphere (evasion>deposition) and the reasons for this are discussed. Overall, the studies reported here provide further clarification on the factors controlling evasion of Hg0 from the ocean surface, and the role of anthropogenic inputs in influencing ocean Hg concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70004693','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70004693"><span><span class="hlt">Exchange</span> of Groundwater and Surface-Water Mediated by Permafrost Response to Seasonal and Long Term <span class="hlt">Air</span> Temperature Variation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ge, Shemin; McKenzie, Jeffrey; Voss, Clifford; Wu, Qingbai</p> <p>2011-01-01</p> <p>Permafrost dynamics impact hydrologic cycle processes by promoting or impeding groundwater and surface water <span class="hlt">exchange</span>. Under seasonal and decadal <span class="hlt">air</span> temperature variations, permafrost temperature changes control the <span class="hlt">exchanges</span> between groundwater and surface water. A coupled heat transport and groundwater flow model, SUTRA, was modified to simulate groundwater flow and heat transport in the subsurface containing permafrost. The northern central Tibet Plateau was used as an example of model application. Modeling results show that in a yearly cycle, groundwater flow occurs in the active layer from May to October. Maximum groundwater discharge to the surface lags the maximum subsurface temperature by two months. Under an increasing <span class="hlt">air</span> temperature scenario of 3?C per 100 years, over the initial 40-year period, the active layer thickness can increase by three-fold. Annual groundwater discharge to the surface can experience a similar three-fold increase in the same period. An implication of these modeling results is that with increased warming there will be more groundwater flow in the active layer and therefore increased groundwater discharge to rivers. However, this finding only holds if sufficient upgradient water is available to replenish the increased discharge. Otherwise, there will be an overall lowering of the water table in the recharge portion of the catchment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035273','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035273"><span><span class="hlt">Exchange</span> of groundwater and surface-water mediated by permafrost response to seasonal and long term <span class="hlt">air</span> temperature variation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ge, S.; McKenzie, J.; Voss, C.; Wu, Q.</p> <p>2011-01-01</p> <p>Permafrost dynamics impact hydrologic cycle processes by promoting or impeding groundwater and surface water <span class="hlt">exchange</span>. Under seasonal and decadal <span class="hlt">air</span> temperature variations, permafrost temperature changes control the <span class="hlt">exchanges</span> between groundwater and surface water. A coupled heat transport and groundwater flow model, SUTRA, was modified to simulate groundwater flow and heat transport in the subsurface containing permafrost. The northern central Tibet Plateau was used as an example of model application. Modeling results show that in a yearly cycle, groundwater flow occurs in the active layer from May to October. Maximum groundwater discharge to the surface lags the maximum subsurface temperature by two months. Under an increasing <span class="hlt">air</span> temperature scenario of 3C per 100 years, over the initial 40-year period, the active layer thickness can increase by three-fold. Annual groundwater discharge to the surface can experience a similar three-fold increase in the same period. An implication of these modeling results is that with increased warming there will be more groundwater flow in the active layer and therefore increased groundwater discharge to rivers. However, this finding only holds if sufficient upgradient water is available to replenish the increased discharge. Otherwise, there will be an overall lowering of the water table in the recharge portion of the catchment. Copyright 2011 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25761782','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25761782"><span>Protein structural dynamics at the gas/water interface examined by hydrogen <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xiao, Yiming; Konermann, Lars</p> <p>2015-08-01</p> <p>Gas/water interfaces (such as <span class="hlt">air</span> bubbles or foam) are detrimental to the stability of proteins, often causing aggregation. This represents a potential problem for industrial processes, for example, the production and handling of protein drugs. Proteins possess surfactant-like properties, resulting in a high affinity for gas/water interfaces. The tendency of previously buried nonpolar residues to maximize contact with the gas phase can cause significant structural distortion. Most earlier studies in this area employed spectroscopic tools that could only provide limited information. Here we use hydrogen/deuterium <span class="hlt">exchange</span> (HDX) <span class="hlt">mass</span> spectrometry (MS) for probing the conformational dynamics of the model protein myoglobin (Mb) in the presence of N(2) bubbles. HDX/MS relies on the principle that unfolded and/or highly dynamic regions undergo faster deuteration than tightly folded segments. In bubble-free solution Mb displays EX2 behavior, reflecting the occurrence of short-lived excursions to partially unfolded conformers. A dramatically different behavior is seen in the presence of N(2) bubbles; EX2 dynamics still take place, but in addition the protein shows EX1 behavior. The latter results from interconversion of the native state with conformers that are globally unfolded and long-lived. These unfolded species likely correspond to Mb that is adsorbed to the surface of gas bubbles. N(2) sparging also induces aggregation. To explain the observed behavior we propose a simple model, that is, "semi-unfolded" ↔ "native" ↔ "globally unfolded" → "aggregated". This model quantitatively reproduces the experimentally observed kinetics. To the best of our knowledge, the current study marks the first exploration of surface denaturation phenomena by HDX/MS. © 2015 The Protein Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29445070','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29445070"><span>Development to term of sheep embryos reconstructed after inner cell <span class="hlt">mass</span>/trophoblast <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loi, Pasqualino; Galli, Cesare; Lazzari, Giovanna; Matsukawa, Kazutsugu; Fulka, Josef; Goeritz, Frank; Hildebrandt, Thomas B</p> <p>2018-04-13</p> <p>Here we report in vitro and term development of sheep embryos after the inner cell <span class="hlt">mass</span> (ICM) from one set of sheep blastocysts were injected into the trophoblast vesicles of another set. We also observed successful in vitro development of chimeric blastocysts made from sheep trophoblast vesicles injected with bovine ICM. First, we dissected ICMs from 35 sheep blastocysts using a stainless steel microblade and injected them into 29 re-expanded sheep trophoblastic vesicles. Of the 25 successfully micromanipulated trophoblastic vesicles, 15 (51.7%) re-expanded normally and showed proper ICM integration. The seven most well reconstructed embryos were transferred for development to term. Three ewes receiving manipulated blastocysts were pregnant at day 45 (42.8%), and all delivered normal offspring (singletons, two females and one male, average weight: 3.54 ± 0.358 kg). Next, we monitored in vitro development of sheep trophoblasts injected with bovine ICMs. Of 17 injected trophoblastic vesicles, 10 (58.8%) re-expanded after 4 h in culture, and four (40%) exhibited integrated bovine ICM. Our results indicate that ICM/trophoblast <span class="hlt">exchange</span> is feasible, allowing full term development with satisfactory lambing rate. Therefore, ICM <span class="hlt">exchange</span> is a promising approach for endangered species conservation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AtmEn..60...88C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AtmEn..60...88C"><span>Atmospheric pollutants in Chiang Mai (Thailand) over a five-year period (2005-2009), their possible sources and relation to <span class="hlt">air</span> <span class="hlt">mass</span> movement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chantara, Somporn; Sillapapiromsuk, Sopittaporn; Wiriya, Wan</p> <p>2012-12-01</p> <p>Monitoring and analysis of the chemical composition of <span class="hlt">air</span> pollutants were conducted over a five-year period (2005-2009) in the sub-urban area of Chiang Mai, Thailand. This study aims to determine the seasonal variation of atmospheric ion species and gases, examine their correlations, identify possible sources and assess major <span class="hlt">air</span>-flow patterns to the receptor. The dominant gas and particulate pollutants were NH3 (43-58%) and SO42- (39-48%), respectively. The annual mean concentrations of NH3 (μg m-3) in descending order were 4.08 (2009) > 3.32 (2007) > 2.68 (2008) > 2.47 (2006) and 1.87 (2005), while those of SO42- (μg m-3) were 2.60 (2007) > 2.20 (2006) > 1.95 (2009) > 1.75 (2008) and 1.26 (2005). Concentrations of particulate ions were analyzed by principle component analysis to find out the possible sources of <span class="hlt">air</span> pollutants in this area. The first component of each year had a high loading of SO42- and NH4+, which probably came from fuel combustion and agricultural activity, respectively. K+, a tracer of biomass burning, also contributed to the first or the second components of each year. Concentrations of NH4+ and SO42- were well correlated (r > 0.777, p < 0.01), which lead to the conclusion that (NH4)2SO4 was a major compound present in this area. The 3-day backward trajectories of <span class="hlt">air</span> <span class="hlt">mass</span> arriving at Chiang Mai from 2005 to 2009 were analyzed using the hybrid single particle langrangian integrated trajectory (HYSPLIT) model and grouped by cluster analysis. The <span class="hlt">air</span> <span class="hlt">mass</span> data was analyzed for the dry season (n = 18; 100%). The trajectory of <span class="hlt">air</span> <span class="hlt">mass</span> in 2005 mainly originated locally (67%). In 2006, the recorded data showed that 56% of <span class="hlt">air</span> <span class="hlt">mass</span> was emitted from the western continental region of Thailand. In 2007, the percent ratios from the western and eastern continental areas were equal (39%). In 2008, 67% originated from the western continental area. In 2009, the recorded <span class="hlt">air</span> <span class="hlt">mass</span> mainly came from the western continental area (72%). In conclusion, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27269384','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27269384"><span>Seasonal variation in diffusive <span class="hlt">exchange</span> of polycyclic aromatic hydrocarbons across the <span class="hlt">air</span>-seawater interface in coastal urban area.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Seung-Kyu; Chae, Doo Hyun</p> <p>2016-08-15</p> <p>Concentrations of 15 polycyclic aromatic hydrocarbons (PAHs) in <span class="hlt">air</span>-seawater interface were measured over 1year in the coastal region of Incheon, South Korea. Most individual PAHs and total PAHs in <span class="hlt">air</span> displayed statistically significant negative correlations with temperature, but not significant in seawater. Less hydrophobic compounds with three rings were at or near equilibrium in summer, while PAHs with four to six rings were in disequilibrium in all seasons, with higher fugacity gradients in colder seasons and for more hydrophobic compounds. Differently from fugacity gradients, the highest net fluxes occurred for some three- and four-ring PAHs showing the highest atmospheric concentrations. Net gaseous <span class="hlt">exchange</span>, which was higher in winter, occurred from <span class="hlt">air</span> to seawater with an annual cumulative flux of 2075μg/m(2)/year (for Σ15PAHs), indicating that atmospheric PAHs in this region, originating from coal/biomass combustion, can deteriorate the quality of seawater and sediment. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NewAR..70....1N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NewAR..70....1N"><span>A critical review of period analyses and implications for <span class="hlt">mass</span> <span class="hlt">exchange</span> in W UMa eclipsing binaries: Paper 3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nelson, R. H.; Terrell, D.; Milone, E. F.</p> <p>2016-02-01</p> <p>This is the third of a series of four papers, the goal of which is to identify the overcontact eclipsing binary star systems for which a solid case can be made for <span class="hlt">mass</span> <span class="hlt">exchange</span>. To reach this goal, it is necessary first to identify those systems for which there is a strong case for period change. We have identified 60 candidate systems; in the first two papers (Nelson et al. 2014, 2016) we discussed 40 individual cases; this paper continues with the last 20. For each system, we present a detailed discussion and evaluation concerning the observational and interpretive material presented in the literature. At least one eclipse timing (ET) diagram, commonly referred to as an "O-C diagram", that includes the latest available data, accompanies each discussion. In paper 4, we will discuss the mechanisms that can cause period change and which of the 60 systems can be reliably concluded to exhibit <span class="hlt">mass</span> <span class="hlt">exchange</span>; we will also provide a list of marginal and rejected cases - suitable for future work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10548806','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10548806"><span>Airborne <span class="hlt">mass</span> spectrometers: four decades of atmospheric and space research at the <span class="hlt">Air</span> Force research laboratory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Viggiano, A A; Hunton, D E</p> <p>1999-11-01</p> <p><span class="hlt">Mass</span> spectrometry is a versatile research tool that has proved to be extremely useful for exploring the fundamental nature of the earth's atmosphere and ionosphere and in helping to solve operational problems facing the <span class="hlt">Air</span> Force and the Department of Defense. In the past 40 years, our research group at the <span class="hlt">Air</span> Force Research Laboratory has flown quadrupole <span class="hlt">mass</span> spectrometers of many designs on nearly 100 sounding rockets, nine satellites, three Space Shuttles and many missions of high-altitude research aircraft and balloons. We have also used our instruments in ground-based investigations of rocket and jet engine exhaust, combustion chemistry and microwave breakdown chemistry. This paper is a review of the instrumentation and techniques needed for space research, a summary of the results from many of the experiments, and an introduction to the broad field of atmospheric and space <span class="hlt">mass</span> spectrometry in general. Copyright 1999 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070023751&hterms=air+asia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dair%2Basia','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070023751&hterms=air+asia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dair%2Basia"><span>High Lapse Rates in <span class="hlt">AIRS</span> Retrieved Temperatures in Cold <span class="hlt">Air</span> Outbreaks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fetzer, Eric J.; Kahn, Brian; Olsen, Edward T.; Fishbein, Evan</p> <p>2004-01-01</p> <p>The Atmospheric Infrared Sounder (<span class="hlt">AIRS</span>) experiment, on NASA's Aqua spacecraft, uses a combination of infrared and microwave observations to retrieve cloud and surface properties, plus temperature and water vapor profiles comparable to radiosondes throughout the troposphere, for cloud cover up to 70%. The high spectral resolution of <span class="hlt">AIRS</span> provides sensitivity to important information about the near-surface atmosphere and underlying surface. A preliminary analysis of <span class="hlt">AIRS</span> temperature retrievals taken during January 2003 reveals extensive areas of superadiabatic lapse rates in the lowest kilometer of the atmosphere. These areas are found predominantly east of North America over the Gulf Stream, and, off East Asia over the Kuroshio Current. Accompanying the high lapse rates are low <span class="hlt">air</span> temperatures, large sea-<span class="hlt">air</span> temperature differences, and low relative humidities. Imagery from a Visible / Near Infrared instrument on the <span class="hlt">AIRS</span> experiment shows accompanying clouds. These lines of evidence all point to shallow convection in the bottom layer of a cold <span class="hlt">air</span> <span class="hlt">mass</span> overlying warm water, with overturning driven by heat flow from ocean to atmosphere. An examination of operational radiosondes at six coastal stations in Japan shows <span class="hlt">AIRS</span> to be oversensitive to lower tropospheric lapse rates due to systematically warm near-surface <span class="hlt">air</span> temperatures. The bias in near-surface <span class="hlt">air</span> temperature is seen to be independent of sea surface temperature, however. <span class="hlt">AIRS</span> is therefore sensitive to <span class="hlt">air</span>-sea temperature difference, but with a warm atmospheric bias. A regression fit to radiosondes is used to correct <span class="hlt">AIRS</span> near-surface retrieved temperatures, and thereby obtain an estimate of the true atmosphere-ocean thermal contrast in five subtropical regions across the north Pacific. Moving eastward, we show a systematic shift in this <span class="hlt">air</span>-sea temperature differences toward more isothermal conditions. These results, while preliminary, have implications for our understanding of heat flow from ocean to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040053519','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040053519"><span>Material Properties Governing Co-Current Flame Spread: The Effect of <span class="hlt">Air</span> Entrainment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coutin, Mickael; Rangwala, Ali S.; Torero, Jose L.; Buckley, Steven G.</p> <p>2003-01-01</p> <p>A study on the effects of lateral <span class="hlt">air</span> entrainment on an upward spreading flame has been conducted. The fuel is a flat PMMA plate of constant length and thickness but variable width. Video images and surface temperatures have allowed establishing the progression of the pyrolyis front and on the flame stand-off distance. These measurements have been incorporated into a theoretical formulation to establish characteristic <span class="hlt">mass</span> transfer numbers ("B" numbers). The <span class="hlt">mass</span> transfer number is deemed as a material related parameter that could be used to assess the potential of a material to sustain co-current flame spread. The experimental results show that the theoretical formulation fails to describe heat <span class="hlt">exchange</span> between the flame and the surface. The discrepancies seem to be associated to lateral <span class="hlt">air</span> entrainment that lifts the flame off the surface and leads to an over estimation of the local <span class="hlt">mass</span> transfer number. Particle Image Velocimetry (PIV) measurements are in the process of being acquired. These measurements are intended to provide insight on the effect of <span class="hlt">air</span> entrainment on the flame stand-off distance. A brief description of the methodology to be followed is presented here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4352854','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4352854"><span>Neutral Poly-/perfluoroalkyl Substances in <span class="hlt">Air</span> and Snow from the Arctic</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xie, Zhiyong; Wang, Zhen; Mi, Wenying; Möller, Axel; Wolschke, Hendrik; Ebinghaus, Ralf</p> <p>2015-01-01</p> <p>Levels of neutral poly-/perfluoroalkyl substances (nPFASs) in <span class="hlt">air</span> and snow collected from Ny-Ålesund were measured and their <span class="hlt">air</span>-snow <span class="hlt">exchange</span> was determined to investigate whether they could re-volatilize into the atmosphere driven by means of <span class="hlt">air</span>-snow <span class="hlt">exchange</span>. The total concentration of 12 neutral PFASs ranged from 6.7 to 39 pg m−3 in <span class="hlt">air</span> and from 330 to 690 pg L−1 in snow. A significant log-linear relationship was observed between the gas/particle partition coefficient and vapor pressure of the neutral PFASs. For fluorotelomer alcohol (FTOHs) and fluorotelomer acrylates (FTAs), the <span class="hlt">air</span>-snow <span class="hlt">exchange</span> fluxes were positive, indicating net evaporative from snow into <span class="hlt">air</span>, while net deposition into snow was observed for perfluorooctane sulfonamidoethanols (Me/EtFOSEs) in winter and spring of 2012. The <span class="hlt">air</span>-snow <span class="hlt">exchange</span> was snow-phase controlled for FTOHs and FTAs, and controlled by the <span class="hlt">air</span>-phase for FOSEs. <span class="hlt">Air</span>-snow <span class="hlt">exchange</span> may significantly interfere with atmospheric concentrations of neutral PFASs in the Arctic. PMID:25746440</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title47-vol2/pdf/CFR-2014-title47-vol2-sec22-880.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title47-vol2/pdf/CFR-2014-title47-vol2-sec22-880.pdf"><span>47 CFR 22.880 - Information <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... 47 Telecommunication 2 2014-10-01 2014-10-01 false Information <span class="hlt">exchange</span>. 22.880 Section 22.880...-Ground Radiotelephone Service Commercial Aviation <span class="hlt">Air</span>-Ground Systems § 22.880 Information <span class="hlt">exchange</span>. (a...-ground system licensee must provide the following information to the public safety/CII licensee at least...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title47-vol2/pdf/CFR-2012-title47-vol2-sec22-880.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title47-vol2/pdf/CFR-2012-title47-vol2-sec22-880.pdf"><span>47 CFR 22.880 - Information <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... 47 Telecommunication 2 2012-10-01 2012-10-01 false Information <span class="hlt">exchange</span>. 22.880 Section 22.880...-Ground Radiotelephone Service Commercial Aviation <span class="hlt">Air</span>-Ground Systems § 22.880 Information <span class="hlt">exchange</span>. (a...-ground system licensee must provide the following information to the public safety/CII licensee at least...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol2/pdf/CFR-2013-title47-vol2-sec22-880.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol2/pdf/CFR-2013-title47-vol2-sec22-880.pdf"><span>47 CFR 22.880 - Information <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... 47 Telecommunication 2 2013-10-01 2013-10-01 false Information <span class="hlt">exchange</span>. 22.880 Section 22.880...-Ground Radiotelephone Service Commercial Aviation <span class="hlt">Air</span>-Ground Systems § 22.880 Information <span class="hlt">exchange</span>. (a...-ground system licensee must provide the following information to the public safety/CII licensee at least...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title47-vol2/pdf/CFR-2011-title47-vol2-sec22-880.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title47-vol2/pdf/CFR-2011-title47-vol2-sec22-880.pdf"><span>47 CFR 22.880 - Information <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... 47 Telecommunication 2 2011-10-01 2011-10-01 false Information <span class="hlt">exchange</span>. 22.880 Section 22.880...-Ground Radiotelephone Service Commercial Aviation <span class="hlt">Air</span>-Ground Systems § 22.880 Information <span class="hlt">exchange</span>. (a...-ground system licensee must provide the following information to the public safety/CII licensee at least...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7785756','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7785756"><span>[Heat and moisture <span class="hlt">exchangers</span> for conditioning of inspired <span class="hlt">air</span> of intubated patients in intensive care. The humidification properties of passive <span class="hlt">air</span> <span class="hlt">exchangers</span> under clinical conditions].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rathgeber, J; Züchner, K; Kietzmann, D; Weyland, W</p> <p>1995-04-01</p> <p>Heat and moisture <span class="hlt">exchangers</span> (HME) are used as artificial noses for intubated patients to prevent tracheo-bronchial or pulmonary damage resulting from dry and cold inspired gases. HME are mounted directly on the tracheal tube, where they collect a large fraction of the heat and moisture of the expired <span class="hlt">air</span>, adding this to the subsequent inspired breath. The effective performance depends on the water-retention capacity of the HME: the amount of water added to the inspired gas cannot exceed the stored water uptake of the previous breath. This study evaluates the efficiency of four different HME under laboratory and clinical conditions using a new moisture-measuring device. METHODS. In a first step, the absolute efficiency of four different HME (DAR Hygrobac, Gibeck Humid-Vent 2P, Pall BB 22-15 T, and Pall BB 100) was evaluated using a lung model simulating physiological heat and humidity conditions of the upper airways. The model was ventilated with tidal volumes of 500, 1,000, and 1,500 ml and different flow rates. The water content of the ventilated <span class="hlt">air</span> was determined between tracheal tube and HME using a new high-resolution humidity meter and compared with the absolute water loss of the exhaled <span class="hlt">air</span> at the gas outlet of a Siemens Servo C ventilator measured with a dew-point hygrometer. Secondly, the moisturizing efficiency was evaluated under clinical conditions in an intensive care unit with 25 intubated patients. Maintaining the ventilatory conditions for each patient, the HME were randomly changed. The humidity data were determined as described above and compared with the laboratory findings. RESULTS AND DISCUSSION. The water content at the respirator outlet is inversely equivalent to the humidity of the inspired gases and represents the water loss from the respiratory tract if the patient is ventilated with dry gases. Moisture retention and heating capacity decreased with higher volumes and higher flow rates. These data are simple to obtain without affecting the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16575583','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16575583"><span>An objective classification system of <span class="hlt">air</span> <span class="hlt">mass</span> types for Szeged, Hungary, with special attention to plant pollen levels.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Makra, László; Juhász, Miklós; Mika, János; Bartzokas, Aristides; Béczi, Rita; Sümeghy, Zoltán</p> <p>2006-07-01</p> <p>This paper discusses the characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types over the Carpathian Basin in relation to plant pollen levels over annual pollination periods. Based on the European Centre for Medium-Range Weather Forecasts dataset, daily sea-level pressure fields analysed at 00 UTC were prepared for each <span class="hlt">air</span> <span class="hlt">mass</span> type (cluster) in order to relate sea-level pressure patterns to pollen levels in Szeged, Hungary. The database comprises daily values of 12 meteorological parameters and daily pollen concentrations of 24 species for their pollination periods from 1997 to 2001. Characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types were objectively defined via factor analysis and cluster analysis. According to the results, nine <span class="hlt">air</span> <span class="hlt">mass</span> types (clusters) were detected for pollination periods of the year corresponding to pollen levels that appear with higher concentration when irradiance is moderate while wind speed is moderate or high. This is the case when an anticyclone prevails in the region west of the Carpathian Basin and when Hungary is under the influence of zonal currents (wind speed is high). The sea level pressure systems associated with low pollen concentrations are mostly similar to those connected to higher pollen concentrations, and arise when wind speed is low or moderate. Low pollen levels occur when an anticyclone prevails in the region west of the Carpathian Basin, as well as when an anticyclone covers the region with Hungary at its centre. Hence, anticyclonic or anticyclonic ridge weather situations seem to be relevant in classifying pollen levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12387399','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12387399"><span>Investigation into the importance of the stomatal pathway in the <span class="hlt">exchange</span> of PCBs between <span class="hlt">air</span> and plants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barber, Jonathan L; Kurt, Perihan B; Thomas, Gareth O; Kerstiens, Gerhard; Jones, Kevin C</p> <p>2002-10-15</p> <p>The transfer of persistent organic pollutants (POPs) from <span class="hlt">air</span> to vegetation is an important <span class="hlt">air</span>-surface <span class="hlt">exchange</span> process that affects global cycling and can result in human and wildlife exposure via the terrestrial food chain. To improve understanding of this process, the role of stomata in uptake of gas-phase polychlorinated biphenyls (PCBs) was investigated using Hemerocallis x hybrida "Black Eyed Stella", a plant with a high stomatal density. Uptake of PCBs was monitored over a 72-h period in the presence and absence of light. Uptake rates were significantly greater in illuminated (stomata open) plants than unilluminated (stomata closed) plants for 18 of the 28 measured PCB congeners (p < 0.05). Depuration of PCBs was monitored in a subsequent experiment over a period of 3 weeks. Levels after 3 weeks of depuration time were still much higher than the concentration prior to contamination. Tri- and tetrachlorinated PCBs showed the greatest depuration, with less than 20% and 50% of accumulated PCBs respectively remaining, while approximately 70% of higher chlorinated PCB congeners remained in the plants at the end of the experiment. Treatments with/without light (to control stomatal opening during uptake) and with/without abscisic acid (ABA) application (to control stomatal opening during depuration) were compared. After contamination indoors for 3 days, there was a significantly higher concentration of PCBs (p < 0.05) in the light contaminated plants than the dark-contaminated plants for 13 of the 28 measured PCB congeners. The ABA treatment affected depuration of PCB-18 only. "Light/ABA-treated" plants had a significantly slower depuration rate for PCB-18 than "light/untreated", "dark/ABA-treated", and "dark/untreated" plants (p < 0.05). The results of the study indicate that there is a stomatal effect on the rate of <span class="hlt">exchange</span> of PCBs between Hemerocallis leaves and <span class="hlt">air</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18336534','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18336534"><span>Particle loading rates for HVAC filters, heat <span class="hlt">exchangers</span>, and ducts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Waring, M S; Siegel, J A</p> <p>2008-06-01</p> <p>The rate at which airborne particulate matter deposits onto heating, ventilation, and <span class="hlt">air</span>-conditioning (HVAC) components is important from both indoor <span class="hlt">air</span> quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle <span class="hlt">mass</span> loading rates for residential and commercial filters, heat <span class="hlt">exchangers</span> (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted <span class="hlt">mass</span> loading rates allow for the assessment of pressure drop and indoor <span class="hlt">air</span> quality consequences that result from particle <span class="hlt">mass</span> loading onto HVAC system components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100042292','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100042292"><span><span class="hlt">Air</span> cycle machine for an aircraft environmental control system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Decrisantis, Angelo A. (Inventor); O'Coin, James R. (Inventor); Taddey, Edmund P. (Inventor)</p> <p>2010-01-01</p> <p>An ECS system includes an ACM mounted adjacent an <span class="hlt">air</span>-liquid heat <span class="hlt">exchanger</span> through a diffuser that contains a diffuser plate. The diffuser plate receives airflow from the ACM which strikes the diffuser plate and flows radially outward and around the diffuser plate and into the <span class="hlt">air</span>-liquid heat <span class="hlt">exchanger</span> to provide minimal pressure loss and proper flow distribution into the <span class="hlt">air</span>-liquid heat <span class="hlt">exchanger</span> with significantly less packaging space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170005404','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170005404"><span>Laser Processed Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hansen, Scott</p> <p>2017-01-01</p> <p>The Laser Processed Heat <span class="hlt">Exchanger</span> project will investigate the use of laser processed surfaces to reduce <span class="hlt">mass</span> and volume in liquid/liquid heat <span class="hlt">exchangers</span> as well as the replacement of the harmful and problematic coatings of the Condensing Heat <span class="hlt">Exchangers</span> (CHX). For this project, two scale unit test articles will be designed, manufactured, and tested. These two units are a high efficiency liquid/liquid HX and a high reliability CHX.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HMT....52.1081G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HMT....52.1081G"><span><span class="hlt">Mass</span> transfer characteristics of bisporus mushroom ( Agaricus bisporus) slices during convective hot <span class="hlt">air</span> drying</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghanbarian, Davoud; Baraani Dastjerdi, Mojtaba; Torki-Harchegani, Mehdi</p> <p>2016-05-01</p> <p>An accurate understanding of moisture transfer parameters, including moisture diffusivity and moisture transfer coefficient, is essential for efficient <span class="hlt">mass</span> transfer analysis and to design new dryers or improve existing drying equipments. The main objective of the present study was to carry out an experimental and theoretical investigation of mushroom slices drying and determine the <span class="hlt">mass</span> transfer characteristics of the samples dried under different conditions. The mushroom slices with two thicknesses of 3 and 5 mm were dried at <span class="hlt">air</span> temperatures of 40, 50 and 60 °C and <span class="hlt">air</span> flow rates of 1 and 1.5 m s-1. The Dincer and Dost model was used to determine the moisture transfer parameters and predict the drying curves. It was observed that the entire drying process took place in the falling drying rate period. The obtained lag factor and Biot number indicated that the moisture transfer in the samples was controlled by both internal and external resistance. The effective moisture diffusivity and the moisture transfer coefficient increased with increasing <span class="hlt">air</span> temperature, <span class="hlt">air</span> flow rate and samples thickness and varied in the ranges of 6.5175 × 10-10 to 1.6726 × 10-9 m2 s-1 and 2.7715 × 10-7 to 3.5512 × 10-7 m s-1, respectively. The validation of the Dincer and Dost model indicated a good capability of the model to describe the drying curves of the mushroom slices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EPJWC..2405004I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EPJWC..2405004I"><span>Time lag between the tropopause height and the levels of 7Be concentration in near surface <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ioannidou, A.; Vasileiadis, A.; Melas, D.</p> <p>2012-04-01</p> <p>The concentration of 7Be at near surface <span class="hlt">air</span> has been determined over 2009, a year of a deep solar minimum, in the region of Thessaloniki, Greece at 40°62' N, 22°95'E. In geomagnetic latitudes over 40° N, the elevation of the tropopause during the warm summer months and the vertical <span class="hlt">exchange</span> of <span class="hlt">air</span> <span class="hlt">masses</span> within the troposphere cause greater mixture of the <span class="hlt">air</span> <span class="hlt">masses</span> resulting in higher concentration levels for 7Be in surface <span class="hlt">air</span>. The positive correlation between the monthly activity concentration of 7Be and the tropopause height (0.94, p < 0.0001), and also between 7Be concentration and the temperature T (°C) (R = 0.97, p < 0.001), confirm that the increased rate of vertical transport within the troposphere, especially during warmer summer months, has as a result the descent to surface of <span class="hlt">air</span> <span class="hlt">masses</span> enriched in 7Be. However, the 7Be concentration levels in near surface <span class="hlt">air</span> are not expected to respond immediately to the change of elevation of the tropopause. It was found that there's a time lag of ~ 3 days between the change in the daily surface concentrations of 7Be the change in the elevation of the tropopause.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ACP....10.8413D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ACP....10.8413D"><span>Aerosol properties associated with <span class="hlt">air</span> <span class="hlt">masses</span> arriving into the North East Atlantic during the 2008 Mace Head EUCAARI intensive observing period: an overview</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dall'Osto, M.; Ceburnis, D.; Martucci, G.; Bialek, J.; Dupuy, R.; Jennings, S. G.; Berresheim, H.; Wenger, J.; Healy, R.; Facchini, M. C.; Rinaldi, M.; Giulianelli, L.; Finessi, E.; Worsnop, D.; Ehn, M.; Mikkilä, J.; Kulmala, M.; O'Dowd, C. D.</p> <p>2010-09-01</p> <p>As part of the EUCAARI Intensive Observing Period, a 4-week campaign to measure aerosol physical, chemical and optical properties, atmospheric structure, and cloud microphysics was conducted from mid-May to mid-June, 2008 at the Mace Head Atmospheric Research Station, located at the interface of Western Europe and the N. E. Atlantic and centered on the west Irish coastline. During the campaign, continental <span class="hlt">air</span> <span class="hlt">masses</span> comprising both young and aged continental plumes were encountered, along with polar, Arctic and tropical <span class="hlt">air</span> <span class="hlt">masses</span>. Polluted-continental aerosol concentrations were of the order of 3000 cm-3, while background marine <span class="hlt">air</span> aerosol concentrations were between 400-600 cm-3. The highest marine <span class="hlt">air</span> concentrations occurred in polar <span class="hlt">air</span> <span class="hlt">masses</span> in which a 15 nm nucleation mode, with concentration of 1100 cm-3, was observed and attributed to open ocean particle formation. Continental <span class="hlt">air</span> submicron chemical composition (excluding refractory sea salt) was dominated by organic matter, closely followed by sulphate <span class="hlt">mass</span>. Although the concentrations and size distribution spectral shape were almost identical for the young and aged continental cases, hygroscopic growth factors (GF) and cloud condensation nuclei (CCN) to total condensation nuclei (CN) concentration ratios were significantly less in the younger pollution plume, indicating a more oxidized organic component to the aged continental plume. The difference in chemical composition and hygroscopic growth factor appear to result in a 40-50% impact on aerosol scattering coefficients and Aerosol Optical Depth, despite almost identical aerosol microphysical properties in both cases, with the higher values been recorded for the more aged case. For the CCN/CN ratio, the highest ratios were seen in the more age plume. In marine <span class="hlt">air</span>, sulphate <span class="hlt">mass</span> dominated the sub-micron component, followed by water soluble organic carbon, which, in turn, was dominated by methanesulphonic acid (MSA). Sulphate concentrations were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24732885','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24732885"><span>Decomposing the profile of PM in two low polluted German cities--mapping of <span class="hlt">air</span> <span class="hlt">mass</span> residence time, focusing on potential long range transport impacts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dimitriou, Konstantinos; Kassomenos, Pavlos</p> <p>2014-07-01</p> <p>This paper aims to decompose the profile of particulates in Karlsruhe and Potsdam (Germany), focusing on the localization of PM potential transboundary sources. An <span class="hlt">air</span> <span class="hlt">mass</span> cluster analysis was implemented, followed by a study of <span class="hlt">air</span> <span class="hlt">mass</span> residence time on a grid of a 0.5° × 0.5° resolution. Particulate/gaseous daily <span class="hlt">air</span> pollution and meteorological data were used to indicate PM local sources. Four Principal Component Analysis (PCA) components were produced: traffic, photochemical, industrial/domestic and particulate. PM2.5/PM10 ratio seasonal trends, indicated production of PMCOARSE (PM10-PM2.5) from secondary sources in Potsdam during warm period (WP). The residing areas of incoming slow moving <span class="hlt">air</span> <span class="hlt">masses</span> are potential transboundary PM sources. For Karlsruhe those areas were mainly around the city. An <span class="hlt">air</span> <span class="hlt">mass</span> residence time secondary peak was observed over Stuttgart. For Potsdam, areas with increased dwelling time of the arriving <span class="hlt">air</span> parcels were detected particularly above E/SE Germany. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018TDM.....5b5012Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018TDM.....5b5012Z"><span>Liquid phase <span class="hlt">mass</span> production of <span class="hlt">air</span>-stable black phosphorus/phospholipids nanocomposite with ultralow tunneling barrier</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Qiankun; Liu, Yinan; Lai, Jiawei; Qi, Shaomian; An, Chunhua; Lu, Yao; Duan, Xuexin; Pang, Wei; Zhang, Daihua; Sun, Dong; Chen, Jian-Hao; Liu, Jing</p> <p>2018-04-01</p> <p>Few-layer black phosphorus (FLBP), a recently discovered two-dimensional semiconductor, has attracted substantial attention in the scientific and technical communities due to its great potential in electronic and optoelectronic applications. However, reactivity of FLBP flakes with ambient species limits its direct applications. Among various methods to passivate FLBP in ambient environment, nanocomposites mixing FLBP flakes with stable matrix may be one of the most promising approaches for industry applications. Here, we report a simple one-step procedure to <span class="hlt">mass</span> produce <span class="hlt">air</span>-stable FLBP/phospholipids nanocomposite in liquid phase. The resultant nanocomposite is found to have ultralow tunneling barrier for charge carriers which can be described by an Efros-Shklovskii variable range hopping mechanism. Devices made from such <span class="hlt">mass</span>-produced FLBP/phospholipids nanocomposite show highly stable electrical conductivity and opto-electrical response in ambient conditions, indicating its promising applications in both electronic and optoelectronic applications. This method could also be generalized to the <span class="hlt">mass</span> production of nanocomposites consisting of other <span class="hlt">air</span>-sensitive 2D materials, such as FeSe, NbSe2, WTe2, etc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ACPD....926265D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ACPD....926265D"><span>Aerosol properties associated with <span class="hlt">air</span> <span class="hlt">masses</span> arriving into the North East Atlantic during the 2008 Mace Head EUCAARI intensive observing period: an overview</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dall'Osto, M.; Ceburnis, D.; Martucci, G.; Bialek, J.; Dupuy, R.; Jennings, S. G.; Berresheim, H.; Wenger, J. C.; Sodeau, J. R.; Healy, R. M.; Facchini, M. C.; Rinaldi, M.; Giulianelli, L.; Finessi, E.; Worsnop, D.; O'Dowd, C. D.</p> <p>2009-12-01</p> <p>As part of the EUCAARI Intensive Observing Period, a 4-week campaign to measure aerosol physical, chemical and optical properties, atmospheric structure, and cloud microphysics was conducted from mid-May to mid-June 2008 at the Mace Head Atmospheric Research Station, located at the interface of Western Europe and the NE Atlantic and centered on the west Irish coastline. During the campaign, continental <span class="hlt">air</span> <span class="hlt">masses</span> comprising both young and aged continental plumes were encountered, along with polar, Arctic and tropical <span class="hlt">air</span> <span class="hlt">masses</span>. Polluted-continental aerosol concentrations were of the order of 3000 cm-3, while background marine <span class="hlt">air</span> aerosol concentrations were between 400-600 cm-3. The highest marine <span class="hlt">air</span> concentrations occurred in polar <span class="hlt">air</span> <span class="hlt">masses</span> in which a 15 nm nucleation mode, with concentration of 1100 cm-3, was observed and attributed to open ocean particle formation. Black carbon concentrations in polluted <span class="hlt">air</span> were between 300-400 ng m-3, and in clean marine <span class="hlt">air</span> were less than 50 ng m-3. Continental <span class="hlt">air</span> submicron chemical composition (excluding refractory sea salt) was dominated by organic matter, closely followed by sulphate <span class="hlt">mass</span>. Although the concentrations and size distribution spectral shape were almost identical for the young and aged continental cases, hygroscopic growth factors (GF) and cloud condensation nuclei (CCN) to total condensation nuclei (CN) concentration ratios were significantly less in the younger pollution plume, indicating a more oxidized organic component to the aged continental plume. The difference in chemical composition and hygroscopic growth factor appear to result in a 40-50% impact on aerosol scattering coefficients and Aerosol Optical Depth, despite almost identical aerosol microphysical properties in both cases, with the higher values been recorded for the more aged case. For the CCN/CN ratio, the highest ratios were seen in the more age plume. In marine <span class="hlt">air</span>, sulphate <span class="hlt">mass</span> dominated the sub-micron component, followed by water</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940019169','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940019169"><span>Study of transient behavior of finned coil heat <span class="hlt">exchangers</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rooke, S. P.; Elissa, M. G.</p> <p>1993-01-01</p> <p>The status of research on the transient behavior of finned coil cross-flow heat <span class="hlt">exchangers</span> using single phase fluids is reviewed. Applications with available analytical or numerical solutions are discussed. Investigation of water-to-<span class="hlt">air</span> type cross-flow finned tube heat <span class="hlt">exchangers</span> is examined through the use of simplified governing equations and an up-wind finite difference scheme. The degenerate case of zero <span class="hlt">air</span>-side capacitance rate is compared with available exact solution. Generalization of the numerical model is discussed for application to multi-row multi-circuit heat <span class="hlt">exchangers</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005GeCoA..69.1841B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005GeCoA..69.1841B"><span>U/Th dating by SHRIMP RG ion-microprobe <span class="hlt">mass</span> spectrometry using single ion-<span class="hlt">exchange</span> beads</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bischoff, James L.; Wooden, Joe; Murphy, Fred; Williams, Ross W.</p> <p>2005-04-01</p> <p>We present a new analytical method for U-series isotopes using the SHRIMP RG (Sensitive High <span class="hlt">mass</span> Resolution Ion MicroProbe) <span class="hlt">mass</span> spectrometer that utilizes the preconcentration of the U-series isotopes from a sample onto a single ion-<span class="hlt">exchange</span> bead. Ion-microprobe <span class="hlt">mass</span> spectrometry is capable of producing Th ionization efficiencies in excess of 2%. Analytical precision is typically better than alpha spectroscopy, but not as good as thermal ionization <span class="hlt">mass</span> spectroscopy (TIMS) and inductively coupled plasma multicollector <span class="hlt">mass</span> spectrometry (ICP-MS). Like TIMS and ICP-MS the method allows analysis of small samples sizes, but also adds the advantage of rapidity of analysis. A major advantage of ion-microprobe analysis is that U and Th isotopes are analyzed in the same bead, simplifying the process of chemical separation. Analytical time on the instrument is ˜60 min per sample, and a single instrument-loading can accommodate 15-20 samples to be analyzed in a 24-h day. An additional advantage is that the method allows multiple reanalyses of the same bead and that samples can be archived for reanalysis at a later time. Because the ion beam excavates a pit only a few μm deep, the mount can later be repolished and reanalyzed numerous times. The method described of preconcentrating a low concentration sample onto a small conductive substrate to allow ion-microprobe <span class="hlt">mass</span> spectrometry is potentially applicable to many other systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70028872','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70028872"><span>U/Th dating by SHRIMP RG ion-microprobe <span class="hlt">mass</span> spectrometry using single ion-<span class="hlt">exchange</span> beads</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bischoff, J.L.; Wooden, J.; Murphy, F.; Williams, Ross W.</p> <p>2005-01-01</p> <p>We present a new analytical method for U-series isotopes using the SHRIMP RG (Sensitive High <span class="hlt">mass</span> Resolution Ion MicroProbe) <span class="hlt">mass</span> spectrometer that utilizes the preconcentration of the U-series isotopes from a sample onto a single ion-<span class="hlt">exchange</span> bead. Ion-microprobe <span class="hlt">mass</span> spectrometry is capable of producing Th ionization efficiencies in excess of 2%. Analytical precision is typically better than alpha spectroscopy, but not as good as thermal ionization <span class="hlt">mass</span> spectroscopy (TIMS) and inductively coupled plasma multicollector <span class="hlt">mass</span> spectrometry (ICP-MS). Like TIMS and ICP-MS the method allows analysis of small samples sizes, but also adds the advantage of rapidity of analysis. A major advantage of ion-microprobe analysis is that U and Th isotopes are analyzed in the same bead, simplifying the process of chemical separation. Analytical time on the instrument is ???60 min per sample, and a single instrument-loading can accommodate 15-20 samples to be analyzed in a 24-h day. An additional advantage is that the method allows multiple reanalyses of the same bead and that samples can be archived for reanalysis at a later time. Because the ion beam excavates a pit only a few ??m deep, the mount can later be repolished and reanalyzed numerous times. The method described of preconcentrating a low concentration sample onto a small conductive substrate to allow ion-microprobe <span class="hlt">mass</span> spectrometry is potentially applicable to many other systems. Copyright ?? 2005 Elsevier Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhPro...3..153O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhPro...3..153O"><span>Influence of power ultrasound application on <span class="hlt">mass</span> transport and microstructure of orange peel during hot <span class="hlt">air</span> drying</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ortuño, Carmen; Pérez-Munuera, Isabel; Puig, Ana; Riera, Enrique; Garcia-Perez, J. V.</p> <p>2010-01-01</p> <p>Power ultrasound application on convective drying of foodstuffs may be considered an emergent technology. This work deals with the influence of power ultrasound on drying of natural materials addressing the kinetic as well as the product's microstructure. Convective drying kinetics of orange peel slabs (thickness 5.95±0.41 mm) were carried out at 40 ∘C and 1 m/s with (US) and without (<span class="hlt">AIR</span>) power ultrasound application. A diffusion model considering external resistance to <span class="hlt">mass</span> transfer was considered to describe drying kinetics. Fresh, US and <span class="hlt">AIR</span> dried samples were analyzed using Cryo-SEM. Results showed that drying kinetics of orange peel were significantly improved by the application of power ultrasound. From modeling, it was observed a significant (p¡0.05) increase in both <span class="hlt">mass</span> transfer coefficient and effective moisture diffusivity. The effects on <span class="hlt">mass</span> transfer properties were confirmed from microestructural observations. In the cuticle surface, the pores were obstructed by wax components scattering, which evidence the ultrasonic effects on the interfaces. The cells of the flavedo were compressed and large intercellular <span class="hlt">air</span> spaces were generated in the albedo facilitating water transfer through it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A31G..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A31G..06D"><span>Characterization of key aerosol, trace gas and meteorological properties and particle formation and growth processes dependent on <span class="hlt">air</span> <span class="hlt">mass</span> origins in coastal Southern Spain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diesch, J.; Drewnick, F.; Sinha, V.; Williams, J.; Borrmann, S.</p> <p>2011-12-01</p> <p>The chemical composition and concentration of aerosols at a certain site can vary depending on season, the <span class="hlt">air</span> <span class="hlt">mass</span> source region and distance from sources. Regardless of the environment, new particle formation (NPF) events are one of the major sources for ultrafine particles which are potentially hazardous to human health. Grown particles are optically active and efficient CCN resulting in important implications for visibility and climate (Zhang et al., 2004). The study presented here is intended to provide information about various aspects of continental, urban and marine <span class="hlt">air</span> <span class="hlt">masses</span> reflected by wind patterns of the <span class="hlt">air</span> arriving at the measurement site. Additionally we will be focusing on NPF events associated with different types of <span class="hlt">air</span> <span class="hlt">masses</span> affecting their emergence and temporal evolution. Measurements of the ambient aerosol, various trace gases and meteorological parameters were performed within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from mid-November to mid-December 2008 at the atmospheric research station "El Arenosillo" located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean. Number and <span class="hlt">mass</span> as well as PAH and black carbon concentrations were measured in PM1 and size distribution instruments covered the size range 6 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol <span class="hlt">Mass</span> Spectrometer (AMS). In order to evaluate the characteristics of different <span class="hlt">air</span> <span class="hlt">masses</span> linking local and regional sources as well as NPF processes, characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types were classified dependent on backwards trajectory pathways and local meteorology. Large nuclei mode concentrations in the number size distribution were found within continental and urban influenced <span class="hlt">air</span> <span class="hlt">mass</span> types due to frequently occurring NPF events. Exploring individual production and sink variables, sulfuric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.C31D..01L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.C31D..01L"><span>Gas <span class="hlt">exchange</span> in the ice zone: the role of small waves and big animals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loose, B.; Takahashi, A.; Bigdeli, A.</p> <p>2016-12-01</p> <p>The balance of <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> and net biological carbon fixation determine the transport and transformation of carbon dioxide and methane in the ocean. <span class="hlt">Air</span>-sea gas <span class="hlt">exchange</span> is mostly driven by upper ocean physics, but biology can also play a role. In the open ocean, gas <span class="hlt">exchange</span> increases proportionate to the square of wind speed. When sea ice is present, this dependence breaks down in part because breaking waves and <span class="hlt">air</span> bubble entrainment are damped out by interactions between sea ice and the wave field. At the same time, sea ice motions, formation, melt, and even sea ice-associated organisms can act to introduce turbulence and <span class="hlt">air</span> bubbles into the upper ocean, thereby enhancing <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span>. We take advantage of the knowledge advances of upper ocean physics including bubble dynamics to formulate a model for <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> in the sea ice zone. Here, we use the model to examine the role of small-scale waves and diving animals that trap <span class="hlt">air</span> for insulation, including penguins, seals and polar bears. We compare these processes to existing parameterizations of wave and bubble dynamics in the open ocean, to observe how sea ice both mitigates and locally enhances <span class="hlt">air</span>-sea gas transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920012282','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920012282"><span>Liquid <span class="hlt">air</span> cycle engines</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rosevear, Jerry</p> <p>1992-01-01</p> <p>Given here is a definition of Liquid <span class="hlt">Air</span> Cycle Engines (LACE) and existing relevant technologies. Heat <span class="hlt">exchanger</span> design and fabrication techniques, the handling of liquid hydrogen to achieve the greatest heat sink capabilities, and <span class="hlt">air</span> decontamination to prevent heat <span class="hlt">exchanger</span> fouling are discussed. It was concluded that technology needs to be extended in the areas of design and fabrication of heat <span class="hlt">exchangers</span> to improve reliability along with weight and volume reductions. Catalysts need to be improved so that conversion can be achieved with lower quantities and lower volumes. Packaging studies need to be investigated both analytically and experimentally. Recycling with slush hydrogen needs further evaluation with experimental testing.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25901845','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25901845"><span>The effect of long-range <span class="hlt">air</span> <span class="hlt">mass</span> transport pathways on PM10 and NO2 concentrations at urban and rural background sites in Ireland: Quantification using clustering techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Donnelly, Aoife A; Broderick, Brian M; Misstear, Bruce D</p> <p>2015-01-01</p> <p>The specific aims of this paper are to: (i) quantify the effects of various long range transport pathways nitrogen dioxide (NO2) and particulate matter with diameter less than 10μm (PM10) concentrations in Ireland and identify <span class="hlt">air</span> <span class="hlt">mass</span> movement corridors which may lead to incidences poor <span class="hlt">air</span> quality for application in forecasting; (ii) compare the effects of such pathways at various sites; (iii) assess pathways associated with a period of decreased <span class="hlt">air</span> quality in Ireland. The origin of and the regions traversed by an <span class="hlt">air</span> <span class="hlt">mass</span> 96h prior to reaching a receptor is modelled and k-means clustering is applied to create <span class="hlt">air-mass</span> groups. Significant differences in <span class="hlt">air</span> pollution levels were found between <span class="hlt">air</span> <span class="hlt">mass</span> cluster types at urban and rural sites. It was found that easterly or recirculated <span class="hlt">air</span> <span class="hlt">masses</span> lead to higher NO2 and PM10 levels with average NO2 levels varying between 124% and 239% of the seasonal mean and average PM10 levels varying between 103% and 199% of the seasonal mean at urban and rural sites. Easterly <span class="hlt">air</span> <span class="hlt">masses</span> are more frequent during winter months leading to higher overall concentrations. The span in relative concentrations between <span class="hlt">air</span> <span class="hlt">mass</span> clusters is highest at the rural site indicating that regional factors are controlling concentration levels. The methods used in this paper could be applied to assist in modelling and forecasting <span class="hlt">air</span> quality based on long range transport pathways and forecast meteorology without the requirement for detailed emissions data over a large regional domain or the use of computationally demanding modelling techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24209303','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24209303"><span>Application of high performance liquid chromatography with inductively coupled plasma <span class="hlt">mass</span> spectrometry (HPLC-ICP-MS) for determination of chromium compounds in the <span class="hlt">air</span> at the workplace.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stanislawska, Magdalena; Janasik, Beata; Wasowicz, Wojciech</p> <p>2013-12-15</p> <p>The toxicity and bioavailability of chromium species are highly dependable on the form or species, therefore determination of total chromium is insufficient for a complete toxicological evaluation and risk assessment. An analytical method for determination of soluble and insoluble Cr (III) and Cr (VI) compounds in welding fume at workplace <span class="hlt">air</span> has been developed. The total chromium (Cr) was determined by using quadruple inductively coupled plasma <span class="hlt">mass</span> spectrometry (ICP-MS) equipped with a dynamic reaction cell (DRC(®)). Soluble trivalent and hexavalent chromium compounds were determined by high performance liquid chromatography with inductively coupled plasma <span class="hlt">mass</span> spectrometry (HPLC-ICP-MS). A high-speed, reversed-phase CR C8 column (PerkinElmer, Inc., Shelton, CT, USA) was used for the speciation of soluble Cr (III) and soluble Cr (VI). The separation was accomplished by interaction of the chromium species with the different components of the mobile phase. Cr (III) formed a complex with EDTA, i.e. retained on the column, while Cr (VI) existed in the solutions as dichromate. Alkaline extraction (2% KOH and 3% Na2CO3) and anion <span class="hlt">exchange</span> column (PRP-X100, PEEK, Hamilton) were used for the separation of the total Cr (VI). The results of the determination of Cr (VI) were confirmed by the analysis of the certified reference material BCR CRM 545 (Cr (VI) in welding dust). The results obtained for the certified material (40.2±0.6 g kg(-1)) and the values recorded in the examined samples (40.7±0.6 g kg(-1)) were highly consistent. This analytical method was applied for the determination of chromium in the samples in the workplace <span class="hlt">air</span> collected onto glass (Whatman, Ø 37 mm) and membrane filters (Sartorius, 0.8 μm, Ø 37 mm). High performance liquid chromatography with inductively coupled plasma <span class="hlt">mass</span> spectrometry is a remarkably powerful and versatile technique for determination of chromium species in welding fume at workplace <span class="hlt">air</span>. Crown Copyright © 2013 Published by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ACP....13.5325E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ACP....13.5325E"><span><span class="hlt">Air</span>-surface <span class="hlt">exchange</span> measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Edwards, G. C.; Howard, D. A.</p> <p>2013-05-01</p> <p>This paper presents the first gaseous elemental mercury (GEM) <span class="hlt">air</span>-surface <span class="hlt">exchange</span> measurements obtained over naturally enriched and background (<0.1 μg g-1 Hg) terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m-2 h-1 to 113 ± 6 ng m-2 h-1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m-2 h-1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. For periods of deposition, dry deposition velocities ranged from 0.00025 cm s-1 to 0.0083 cm s-1 with an average of 0.0041 ± 0.00018 cm s-1, representing bare soil, nighttime conditions. Comparison of the Australian data to North American data suggests the need for Australian-specific mercury <span class="hlt">air</span>-surface <span class="hlt">exchange</span> data representative of Australia's unique climatic conditions, vegetation types, land use patterns and soils.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1208301','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1208301"><span>[Comparative study of respiratory <span class="hlt">exchanging</span> surfaces in birds and mammals].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jammes, Y</p> <p>1975-01-01</p> <p>Anatomical studies of the respiratory apparatus of birds show evidences for a gas <span class="hlt">exchanging</span> tubular system (parabronchi and <span class="hlt">air</span> capillaries); these <span class="hlt">exchanging</span> structures are entirely dissociated from the ventilatory drive acting on the <span class="hlt">air</span> sacs. A "cross-current" gas <span class="hlt">exchanging</span> system (perpendicular disposition of <span class="hlt">air</span> and blood capillaries) allow a good wash-out of carbon dioxide (PaCO2 lower than PECO2). The great efficiency of this lung is allowed by its very large diffusive surface (ASa) and by the high values of lung specific oxygen diffusing capacity (DO2/ASa) and of O2 extraction coefficient in inspired <span class="hlt">air</span>. The ventilatory pattern of birds is characterized by a greater tidal volume and a smaller respiratory frequency than in mammals of same weight. Respiratory centers of birds receive afferences from lung stretch receptors, CO2-sensitive lung receptors and arterial chemoreceptors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25950136','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25950136"><span>Measuring <span class="hlt">air</span>-water interfacial area for soils using the <span class="hlt">mass</span> balance surfactant-tracer method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Araujo, Juliana B; Mainhagu, Jon; Brusseau, Mark L</p> <p>2015-09-01</p> <p>There are several methods for conducting interfacial partitioning tracer tests to measure <span class="hlt">air</span>-water interfacial area in porous media. One such approach is the <span class="hlt">mass</span> balance surfactant tracer method. An advantage of the <span class="hlt">mass</span>-balance method compared to other tracer-based methods is that a single test can produce multiple interfacial area measurements over a wide range of water saturations. The <span class="hlt">mass</span>-balance method has been used to date only for glass beads or treated quartz sand. The purpose of this research is to investigate the effectiveness and implementability of the <span class="hlt">mass</span>-balance method for application to more complex porous media. The results indicate that interfacial areas measured with the <span class="hlt">mass</span>-balance method are consistent with values obtained with the miscible-displacement method. This includes results for a soil, for which solid-phase adsorption was a significant component of total tracer retention. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JOM....70c.298M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JOM....70c.298M"><span>Fiber Orientation Effects in Fused Filament Fabrication of <span class="hlt">Air</span>-Cooled Heat <span class="hlt">Exchangers</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mulholland, T.; Goris, S.; Boxleitner, J.; Osswald, T. A.; Rudolph, N.</p> <p>2018-03-01</p> <p>Fused filament fabrication (FFF) is a type of additive manufacturing based on material extrusion that has long been considered a prototyping technology. However, the right application of material, process, and product can be used for manufacturing of end-use products, such as <span class="hlt">air</span>-cooled heat <span class="hlt">exchangers</span> made by adding fillers to the base polymer, enhancing the thermal conductivity. Fiber fillers lead to anisotropic thermal conductivity, which is governed by the process-induced fiber orientation. This article presents an experimental study on the microstructure-property relationship for carbon fiber-filled polyamide used in FFF. The fiber orientation is measured by micro-computed tomography, and the thermal conductivity of manufactured samples is measured. Although the thermal conductivity is raised by more than three times in the fiber orientation direction at a load of only 12 vol.%, the enhancement is low in the other directions, and this anisotropy, along with certain manufacturing restrictions, influences the final part performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5394062-isotopic-exchange-during-derivatization-platelet-activating-factor-gas-chromatography-mass-spectrometry','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5394062-isotopic-exchange-during-derivatization-platelet-activating-factor-gas-chromatography-mass-spectrometry"><span>Isotopic <span class="hlt">exchange</span> during derivatization of platelet activating factor for gas chromatography-<span class="hlt">mass</span> spectrometry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Haroldsen, P.E.; Gaskell, S.J.; Weintraub, S.T.</p> <p>1991-04-01</p> <p>One approach to the quantitative analysis of platelet activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycerol-3-phosphocholine; also referred to as AGEPC, alkyl glyceryl ether phosphocholine) is hydrolytic removal of the phosphocholine group and conversion to an electron-capturing derivative for gas chromatography-negative ion <span class="hlt">mass</span> spectrometry. (2H3)Acetyl-AGEPC has been commonly employed as an internal standard. When 1-hexadecyl-2-(2H3)acetyl glycerol (obtained by enzymatic hydrolysis of (2H3)-C16:0 AGEPC) is treated with pentafluorobenzoyl chloride at 120 degrees C, the resulting 3-pentafluorobenzoate derivative shows extensive loss of the deuterium label. This <span class="hlt">exchange</span> is evidently acid-catalyzed since derivatization of 1-hexadecyl-2-acetyl glycerol under the same conditions in the presence of a trace ofmore » 2HCl results in the incorporation of up to three deuterium atoms. Isotope <span class="hlt">exchange</span> can be avoided if the reaction is carried out at low temperature in the presence of base. Direct derivatization of (2H3)-C16:0 AGEPC by treatment with pentafluorobenzoyl chloride or heptafluorobutyric anhydride also results in loss of the deuterium label. The use of (13C2)-C16:0 AGEPC as an internal standard is recommended for rigorous quantitative analysis.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5902907','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5902907"><span>Development to term of sheep embryos reconstructed after inner cell <span class="hlt">mass</span>/trophoblast <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>LOI, Pasqualino; GALLI, Cesare; LAZZARI, Giovanna; MATSUKAWA, Kazutsugu; FULKA, Josef; GOERITZ, Frank; HILDEBRANDT, Thomas B.</p> <p>2018-01-01</p> <p>Here we report in vitro and term development of sheep embryos after the inner cell <span class="hlt">mass</span> (ICM) from one set of sheep blastocysts were injected into the trophoblast vesicles of another set. We also observed successful in vitro development of chimeric blastocysts made from sheep trophoblast vesicles injected with bovine ICM. First, we dissected ICMs from 35 sheep blastocysts using a stainless steel microblade and injected them into 29 re-expanded sheep trophoblastic vesicles. Of the 25 successfully micromanipulated trophoblastic vesicles, 15 (51.7%) re-expanded normally and showed proper ICM integration. The seven most well reconstructed embryos were transferred for development to term. Three ewes receiving manipulated blastocysts were pregnant at day 45 (42.8%), and all delivered normal offspring (singletons, two females and one male, average weight: 3.54 ± 0.358 kg). Next, we monitored in vitro development of sheep trophoblasts injected with bovine ICMs. Of 17 injected trophoblastic vesicles, 10 (58.8%) re-expanded after 4 h in culture, and four (40%) exhibited integrated bovine ICM. Our results indicate that ICM/trophoblast <span class="hlt">exchange</span> is feasible, allowing full term development with satisfactory lambing rate. Therefore, ICM <span class="hlt">exchange</span> is a promising approach for endangered species conservation. PMID:29445070</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29290633','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29290633"><span>SAM-CAAM: A Concept for Acquiring Systematic Aircraft Measurements to Characterize Aerosol <span class="hlt">Air</span> <span class="hlt">Masses</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kahn, Ralph A; Berkoff, Tim A; Brock, Charles; Chen, Gao; Ferrare, Richard A; Ghan, Steven; Hansico, Thomas F; Hegg, Dean A; Martins, J Vanderlei; McNaughton, Cameron S; Murphy, Daniel M; Ogren, John A; Penner, Joyce E; Pilewskie, Peter; Seinfeld, John H; Worsnop, Douglas R</p> <p>2017-10-01</p> <p>A modest operational program of systematic aircraft measurements can resolve key satellite-aerosol-data-record limitations. Satellite observations provide frequent, global aerosol-amount maps, but offer only loose aerosol property constraints needed for climate and <span class="hlt">air</span> quality applications. We define and illustrate the feasibility of flying an aircraft payload to measure key aerosol optical, microphysical, and chemical properties in situ . The flight program could characterize major aerosol <span class="hlt">air-mass</span> types statistically, at a level-of-detail unobtainable from space. It would: (1) enhance satellite aerosol retrieval products with better climatology assumptions, and (2) improve translation between satellite-retrieved optical properties and species-specific aerosol <span class="hlt">mass</span> and size simulated in climate models to assess aerosol forcing, its anthropogenic components, and other environmental impacts. As such, Systematic Aircraft Measurements to Characterize Aerosol <span class="hlt">Air</span> <span class="hlt">Masses</span> (SAM-CAAM) could add value to data records representing several decades of aerosol observations from space, improve aerosol constraints on climate modeling , help interrelate remote-sensing, in situ, and modeling aerosol-type definitions , and contribute to future satellite aerosol missions. Fifteen Required Variables are identified, and four Payload Options of increasing ambition are defined, to constrain these quantities. "Option C" could meet all the SAM-CAAM objectives with about 20 instruments, most of which have flown before, but never routinely several times per week, and never as a group. Aircraft integration, and approaches to data handling, payload support, and logistical considerations for a long-term, operational mission are discussed. SAM-CAAM is feasible because, for most aerosol sources and specified seasons, particle properties tend to be repeatable , even if aerosol loading varies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..4412324M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..4412324M"><span>Enrichment of Extracellular Carbonic Anhydrase in the Sea Surface Microlayer and Its Effect on <span class="hlt">Air</span>-Sea CO2 <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mustaffa, N. I. H.; Striebel, M.; Wurl, O.</p> <p>2017-12-01</p> <p>This paper describes the quantification of extracellular carbonic anhydrase (eCA) concentrations in the sea surface microlayer (SML), the boundary layer between the ocean and the atmosphere of the Indo-West Pacific. We demonstrated that the SML is enriched with eCA by 1.5 ± 0.7 compared to the mixed underlying water. Enrichment remains up to a wind speed of 7 m s-1 (i.e., under typical oceanic conditions). As eCA catalyzes the interconversion of HCO3- and CO2, it has been hypothesized that its enrichment in the SML enhances the <span class="hlt">air</span>-sea CO2 <span class="hlt">exchange</span>. We detected concentrations in the range of 0.12 to 0.76 n<fi>M</fi>, which can enhance the <span class="hlt">exchange</span> by up to 15% based on the model approach described in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040089954&hterms=infrared+temperature+sensor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dinfrared%2Btemperature%2Bsensor','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040089954&hterms=infrared+temperature+sensor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dinfrared%2Btemperature%2Bsensor"><span>Quantifying energy and <span class="hlt">mass</span> transfer in crop canopies: sensors for measurement of temperature and <span class="hlt">air</span> velocity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bugbee, B.; Monje, O.; Tanner, B.</p> <p>1996-01-01</p> <p>Here we report on the in situ performance of inexpensive, miniature sensors that have increased our ability to measure <span class="hlt">mass</span> and energy fluxes from plant canopies in controlled environments: 1. Surface temperature. Canopy temperature measurements indicate changes in stomatal aperture and thus latent and sensible heat fluxes. Infrared transducers from two manufacturers (Exergen Corporation, Newton, MA; and Everest Interscience, Tucson, AZ, USA) have recently become available. Transducer accuracy matched that of a more expensive hand-held infrared thermometer. 2. <span class="hlt">Air</span> velocity varies above and within plant canopies and is an important component in <span class="hlt">mass</span> and energy transfer models. We tested commercially-available needle, heat-transfer anemometers (1 x 50 mm cylinder) that consist of a fine-wire thermocouple and a heater inside a hypodermic needle. The needle is heated and wind speed determined from the temperature rise above ambient. These sensors are particularly useful in measuring the low wind speeds found within plant canopies. 3. Accurate measurements of <span class="hlt">air</span> temperature adjacent to plant leaves facilitates transport phenomena modeling. We quantified the effect of radiation and <span class="hlt">air</span> velocity on temperature rise in thermocouples from 10 to 500 micrometers. At high radiation loads and low wind speeds, temperature errors were as large as 7 degrees C above <span class="hlt">air</span> temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A11C0071B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A11C0071B"><span>Transport Regimes of <span class="hlt">Air</span> <span class="hlt">Masses</span> Affecting the Tropospheric Composition of the Canadian and European Arctic During RACEPAC 2014 and NETCARE 2014/2015</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bozem, H.; Hoor, P. M.; Koellner, F.; Kunkel, D.; Schneider, J.; Schulz, C.; Herber, A. B.; Borrmann, S.; Wendisch, M.; Ehrlich, A.; Leaitch, W. R.; Willis, M. D.; Burkart, J.; Thomas, J. L.; Abbatt, J.</p> <p>2015-12-01</p> <p>The Arctic is warming much faster than any other place in the world and undergoes a rapid change dominated by a changing climate in this region. The impact of polluted <span class="hlt">air</span> <span class="hlt">masses</span> traveling to the Arctic from various remote sources significantly contributes to the observed climate change, in contrast there are additional local emission sources contributing to the level of pollutants (trace gases and aerosol). Processes affecting the emission and transport of these pollutants are not well understood and need to be further investigated. We present aircraft based trace gas measurements in the Arctic during RACEPAC (2014) and NETCARE (2014 and 2015) with the Polar 6 aircraft of Alfred Wegener Institute (AWI) covering an area from 134°W to 17°W and 68°N to 83°N. We focus on cloud, aerosol and general transport processes of polluted <span class="hlt">air</span> <span class="hlt">masses</span> into the high Arctic. Based on CO and CO2 measurements and kinematic 10-day back trajectories we analyze the transport regimes prevalent during spring (RACEPAC 2014 and NETCARE 2015) and summer (NETCARE 2014) in the observed region. Whereas the eastern part of the Canadian Arctic is affected by <span class="hlt">air</span> <span class="hlt">masses</span> with their origin in Asia, in the central and western parts of the Canadian and European Arctic <span class="hlt">air</span> <span class="hlt">masses</span> from North America are predominant at the time of the measurement. In general the more northern parts of the Arctic were relatively unaffected by pollution from mid-latitudes since <span class="hlt">air</span> <span class="hlt">masses</span> mostly travel within the polar dome, being quite isolated. Associated mixing ratios of CO and CO2 fit into the seasonal cycle observed at NOAA ground stations throughout the Arctic, but show a more mid-latitudinal characteristic at higher altitudes. The transition is remarkably sharp and allows for a chemical definition of the polar dome. At low altitudes, synoptic disturbances transport polluted <span class="hlt">air</span> <span class="hlt">masses</span> from mid-latitudes into regions of the polar dome. These <span class="hlt">air</span> <span class="hlt">masses</span> contribute to the Arctic pollution background, but also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17716909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17716909"><span>Remote <span class="hlt">mass</span> spectrometric sampling of electrospray- and desorption electrospray-generated ions using an <span class="hlt">air</span> ejector.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dixon, R Brent; Bereman, Michael S; Muddiman, David C; Hawkridge, Adam M</p> <p>2007-10-01</p> <p>A commercial <span class="hlt">air</span> ejector was coupled to an electrospray ionization linear ion trap <span class="hlt">mass</span> spectrometer (LTQ) to transport remotely generated ions from both electrospray (ESI) and desorption electrospray ionization (DESI) sources. We demonstrate the remote analysis of a series of analyte ions that range from small molecules and polymers to polypeptides using the AE-LTQ interface. The details of the ESI-AE-LTQ and DESI-AE-LTQ experimental configurations are described and preliminary <span class="hlt">mass</span> spectrometric data are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GBioC..31..901E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GBioC..31..901E"><span>Impacts of ENSO on <span class="hlt">air</span>-sea oxygen <span class="hlt">exchange</span>: Observations and mechanisms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eddebbar, Yassir A.; Long, Matthew C.; Resplandy, Laure; Rödenbeck, Christian; Rodgers, Keith B.; Manizza, Manfredi; Keeling, Ralph F.</p> <p>2017-05-01</p> <p>Models and observations of atmospheric potential oxygen (APO ≃ O2 + 1.1 * CO2) are used to investigate the influence of El Niño-Southern Oscillation (ENSO) on <span class="hlt">air</span>-sea O2 <span class="hlt">exchange</span>. An atmospheric transport inversion of APO data from the Scripps flask network shows significant interannual variability in tropical APO fluxes that is positively correlated with the Niño3.4 index, indicating anomalous ocean outgassing of APO during El Niño. Hindcast simulations of the Community Earth System Model (CESM) and the Institut Pierre-Simon Laplace model show similar APO sensitivity to ENSO, differing from the Geophysical Fluid Dynamics Laboratory model, which shows an opposite APO response. In all models, O2 accounts for most APO flux variations. Detailed analysis in CESM shows that the O2 response is driven primarily by ENSO modulation of the source and rate of equatorial upwelling, which moderates the intensity of O2 uptake due to vertical transport of low-O2 waters. These upwelling changes dominate over counteracting effects of biological productivity and thermally driven O2 <span class="hlt">exchange</span>. During El Niño, shallower and weaker upwelling leads to anomalous O2 outgassing, whereas deeper and intensified upwelling during La Niña drives enhanced O2 uptake. This response is strongly localized along the central and eastern equatorial Pacific, leading to an equatorial zonal dipole in atmospheric anomalies of APO. This dipole is further intensified by ENSO-related changes in winds, reconciling apparently conflicting APO observations in the tropical Pacific. These findings suggest a substantial and complex response of the oceanic O2 cycle to climate variability that is significantly (>50%) underestimated in magnitude by ocean models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RvGeo..50.3002K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RvGeo..50.3002K"><span>Evapotranspiration: A process driving <span class="hlt">mass</span> transport and energy <span class="hlt">exchange</span> in the soil-plant-atmosphere-climate system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katul, Gabriel G.; Oren, Ram; Manzoni, Stefano; Higgins, Chad; Parlange, Marc B.</p> <p>2012-09-01</p> <p>The role of evapotranspiration (ET) in the global, continental, regional, and local water cycles is reviewed. Elevated atmospheric CO2, <span class="hlt">air</span> temperature, vapor pressure deficit (D), turbulent transport, radiative transfer, and reduced soil moisture all impact biotic and abiotic processes controlling ET that must be extrapolated to large scales. Suggesting a blueprint to achieve this link is the main compass of this review. Leaf-scale transpiration (fe) as governed by the plant biochemical demand for CO2 is first considered. When this biochemical demand is combined with <span class="hlt">mass</span> transfer formulations, the problem remains mathematically intractable, requiring additional assumptions. A mathematical "closure" that assumes stomatal aperture is autonomously regulated so as to maximize the leaf carbon gain while minimizing water loss is proposed, which leads to analytical expressions for leaf-scale transpiration. This formulation predicts well the effects of elevated atmospheric CO2 and increases in D on fe. The case of soil moisture stress is then considered using extensive gas <span class="hlt">exchange</span> measurements collected in drought studies. Upscaling the fe to the canopy is then discussed at multiple time scales. The impact of limited soil water availability within the rooting zone on the upscaled ET as well as some plant strategies to cope with prolonged soil moisture stress are briefly presented. Moving further up in direction and scale, the soil-plant system is then embedded within the atmospheric boundary layer, where the influence of soil moisture on rainfall is outlined. The review concludes by discussing outstanding challenges and how to tackle them by means of novel theoretical, numerical, and experimental approaches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950005168','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950005168"><span>Use of radon and cosmogenic radionuclides as indicators of <span class="hlt">exchange</span> between troposphere and stratosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kritz, Mark A.</p> <p>1994-01-01</p> <p>This research grant covered participation in the operational phase of NASA's Stratosphere-Troposphere <span class="hlt">Exchange</span> Project (STEP), a multi-agency airborne science program conducted aboard NASA U-2 and ER-2 high altitude research aircraft. The primary goals of STEP were to investigate the mechanisms of irreversible movement of <span class="hlt">mass</span>, trace gases, and aerosols from the troposphere into the stratosphere, and to explain the observed dryness of the stratosphere. Three flight experiments were conducted to address these questions: two extratropical experiments, in 1984 and 1986, and a tropical experiment, in 1987. The cosmogenic radionuclides Be-7 and P-32, produced in the stratosphere by cosmic rays, and Rn-222 (radon), emitted from continental soils, were well-suited as tracers of intra-stratospheric <span class="hlt">air</span> <span class="hlt">mass</span> movements, and to follow episodes of troposphere to stratosphere <span class="hlt">exchange</span>. Measurements of Be-7 and P-32 were made in all three STEP experiments. Measurements of radon were made in the tropical experiment only. The equipment worked well, and produced a valuable data set in support of the STEP objectives, as indicated by the 'quick-look' results outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol2/pdf/CFR-2010-title14-vol2-sec65-43.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title14-vol2/pdf/CFR-2010-title14-vol2-sec65-43.pdf"><span>14 CFR 65.43 - Rating privileges and <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Rating privileges and <span class="hlt">exchange</span>. 65.43... § 65.43 Rating privileges and <span class="hlt">exchange</span>. (a) The holder of a senior rating on August 31, 1970, may at any time after that date <span class="hlt">exchange</span> his rating for a facility rating at the same <span class="hlt">air</span> traffic control...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.9764F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.9764F"><span>Toward a universal <span class="hlt">mass</span>-momentum transfer relationship for predicting nutrient uptake and metabolite <span class="hlt">exchange</span> in benthic reef communities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Falter, James L.; Lowe, Ryan J.; Zhang, Zhenlin</p> <p>2016-09-01</p> <p>Here we synthesize data from previous field and laboratory studies describing how rates of nutrient uptake and metabolite <span class="hlt">exchange</span> (<span class="hlt">mass</span> transfer) are related to form drag and bottom stresses (momentum transfer). Reanalysis of this data shows that rates of <span class="hlt">mass</span> transfer are highly correlated (r2 ≥ 0.9) with the root of the bottom stress (τbot0.4) under both waves and currents and only slightly higher under waves (~10%). The amount of <span class="hlt">mass</span> transfer that can occur per unit bottom stress (or form drag) is influenced by morphological features ranging anywhere from millimeters to meters in scale; however, surface-scale roughness (millimeters) appears to have little effect on actual nutrient uptake by living reef communities. Although field measurements of nutrient uptake by natural reef communities agree reasonably well with predictions based on existing <span class="hlt">mass</span>-momentum transfer relationships, more work is needed to better constrain these relationships for more rugose and morphologically complex communities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70157933','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70157933"><span>Natural radium and radon tracers to quantify water <span class="hlt">exchange</span> and movement in reservoirs</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Smith, Christopher G.; Baskaran, Mark</p> <p>2011-01-01</p> <p>Radon and radium isotopes are routinely used to quantify <span class="hlt">exchange</span> rates between different hydrologic reservoirs. Since their recognition as oceanic tracers in the 1960s, both radon and radium have been used to examine processes such as <span class="hlt">air</span>-sea <span class="hlt">exchange</span>, deep oceanic mixing, benthic inputs, and many others. Recently, the application of radon-222 and the radium-quartet (223,224,226,228Ra) as coastal tracers has seen a revelation with the growing interest in coastal groundwater dynamics. The enrichment of these isotopes in benthic fluids including groundwater makes both radium and radon ideal tracers of coastal benthic processes (e.g. submarine groundwater discharge). In this chapter we review traditional and recent advances in the application of radon and radium isotopes to understand mixing and <span class="hlt">exchange</span> between various hydrologic reservoirs, specifically: (1) atmosphere and ocean, (2) deep and shallow oceanic water <span class="hlt">masses</span>, (3) coastal groundwater/benthic pore waters and surface ocean, and (4) aquifer-lakes. While the isotopes themselves and their distribution in the environment provide qualitative information about the <span class="hlt">exchange</span> processes, it is mixing/<span class="hlt">exchange</span> and transport models for these isotopes that provide specific quantitative information about these processes. Brief introductions of these models and mixing parameters are provided for both historical and more recent studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2855537','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2855537"><span>Regulation of Phenylalanine Hydroxylase: Conformational Changes Upon Phenylalanine Binding Detected by H/D <span class="hlt">Exchange</span> and <span class="hlt">Mass</span> Spectrometry†</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Jun; Dangott, Lawrence J.; Fitzpatrick, Paul F.</p> <p>2010-01-01</p> <p>Phenylalanine acts as an allosteric activator of the tetrahydropterin-dependent enzyme phenylalanine hydroxylase. Hydrogen/deuterium <span class="hlt">exchange</span> monitored by <span class="hlt">mass</span> spectrometry has been used to gain insight into local conformational changes accompanying activation of rat phenylalanine hydroxylase by phenylalanine. Peptides in the regulatory and catalytic domains that lie in the interface between these two domains show large increases in the extent of deuterium incorporation from solvent in the presence of phenylalanine. In contrast, the effects of phenylalanine on the <span class="hlt">exchange</span> kinetics of a mutant enzyme lacking the regulatory domain are limited to peptides surrounding the binding site for the amino acid substrate. These results support a model in which the N-terminus of the protein acts as an inhibitory peptide, with phenylalanine binding causing a conformational change in the regulatory domain that alters the interaction between the catalytic and regulatory domains. PMID:20307070</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090040085&hterms=heat+exchanger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dheat%2Bexchanger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090040085&hterms=heat+exchanger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dheat%2Bexchanger"><span>Development, Fabrication, and Testing of a Liquid/Liquid Microchannel Heat <span class="hlt">Exchanger</span> for Constellation Spacecrafts</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hawkins-Reynolds, Ebony; Le,Hung; Stephans, Ryan A.</p> <p>2009-01-01</p> <p>Minimizing <span class="hlt">mass</span> and volume is critically important for space hardware. Microchannel technology can be used to decrease both of these parameters for heat <span class="hlt">exchangers</span>. Working in concert with NASA, Pacific Northwest National Laboratories (PNNL) has developed a microchannel liquid/liquid heat <span class="hlt">exchanger</span> that has resulted in significant <span class="hlt">mass</span> and volume savings. The microchannel heat <span class="hlt">exchanger</span> delivers these improvements without sacrificing thermal and pressure drop performance. A conventional heat <span class="hlt">exchanger</span> has been tested and the performance of it recorded to compare it to the microchannel heat <span class="hlt">exchanger</span> that PNNL has fabricated. The microchannel heat <span class="hlt">exchanger</span> was designed to meet all of the requirements of the baseline heat <span class="hlt">exchanger</span>, while reducing the heat <span class="hlt">exchanger</span> <span class="hlt">mass</span> and volume. The baseline heat <span class="hlt">exchanger</span> was designed to have an transfer approximately 3.1 kW for a specific set of inlet conditions. The baseline heat <span class="hlt">exchanger</span> <span class="hlt">mass</span> was 2.7 kg while the microchannel <span class="hlt">mass</span> was only 2.0 kg. More impressive, however, was the volumetric savings associated with the microchannel heat <span class="hlt">exchanger</span>. The microchannel heat <span class="hlt">exchanger</span> was an order of magnitude smaller than the baseline heat <span class="hlt">exchanger</span> (2180cm3 vs. 311 cm3). This paper will describe the test apparatus designed to complete performance tests for both heat <span class="hlt">exchangers</span>. Also described in this paper will be the performance specifications for the microchannel heat <span class="hlt">exchanger</span> and how they compare to the baseline heat <span class="hlt">exchanger</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmEn.107...35V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmEn.107...35V"><span>Influence of <span class="hlt">air</span> <span class="hlt">mass</span> origin on aerosol properties at a remote Michigan forest site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>VanReken, T. M.; Mwaniki, G. R.; Wallace, H. W.; Pressley, S. N.; Erickson, M. H.; Jobson, B. T.; Lamb, B. K.</p> <p>2015-04-01</p> <p>The northern Great Lakes region of North America is a large, relatively pristine area. To date, there has only been limited study of the atmospheric aerosol in this region. During summer 2009, a detailed characterization of the atmospheric aerosol was conducted at the University of Michigan Biological Station (UMBS) as part of the Community Atmosphere-Biosphere Interactions Experiment (CABINEX). Measurements included particle size distribution, water-soluble composition, and CCN activity. Aerosol properties were strongly dependent on the origin of the <span class="hlt">air</span> <span class="hlt">masses</span> reaching the site. For ∼60% of the study period, <span class="hlt">air</span> was transported from sparsely populated regions to the northwest. During these times aerosol loadings were low, with mean number and volume concentrations of 1630 cm-3 and 1.91 μm3 cm-3, respectively. The aerosol during clean periods was dominated by organics, and exhibited low hygroscopicities (mean κ = 0.18 at s = 0.3%). When <span class="hlt">air</span> was from more populated regions to the east and south (∼29% of the time), aerosol properties reflected a stronger anthropogenic influence, with 85% greater particle number concentrations, 2.5 times greater aerosol volume, six times more sulfate <span class="hlt">mass</span>, and increased hygroscopicity (mean к = 0.24 at s = 0.3%). These trends are have the potential to influence forest-atmosphere interactions and should be targeted for future study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1353457-influence-air-mass-origin-aerosol-properties-remote-michigan-forest-site','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1353457-influence-air-mass-origin-aerosol-properties-remote-michigan-forest-site"><span>Influence of <span class="hlt">air</span> <span class="hlt">mass</span> origin on aerosol properties at a remote Michigan forest site</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>VanReken, T. M.; Mwaniki, G. R.; Wallace, H. W.; ...</p> <p>2015-02-10</p> <p>The northern Great Lakes region of North America is a large, relatively pristine area. To date, there has only been limited study of the atmospheric aerosol in this region. During summer 2009, a detailed characterization of the atmospheric aerosol was conducted at the University of Michigan Biological Station (UMBS) as part of the Community Atmosphere–Biosphere Interactions Experiment (CABINEX). Measurements included particle size distribution, water-soluble composition, and CCN activity. Aerosol properties were strongly dependent on the origin of the <span class="hlt">air</span> <span class="hlt">masses</span> reaching the site. For ~60% of the study period, <span class="hlt">air</span> was transported from sparsely populated regions to the northwest. Duringmore » these times aerosol loadings were low, with mean number and volume concentrations of 1630 cm -3 and 1.91 μm 3 cm -3, respectively. The aerosol during clean periods was dominated by organics, and exhibited low hygroscopicities (mean κ = 0.18 at s = 0.3%). When <span class="hlt">air</span> was from more populated regions to the east and south (~29% of the time), aerosol properties reflected a stronger anthropogenic influence, with 85% greater particle number concentrations, 2.5 times greater aerosol volume, six times more sulfate <span class="hlt">mass</span>, and increased hygroscopicity (mean к = 0.24 at s = 0.3%). Furthermore, these trends are have the potential to influence forest–atmosphere interactions and should be targeted for future study.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17737437','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17737437"><span>Condensation of atmospheric moisture from tropical maritime <span class="hlt">air</span> <span class="hlt">masses</span> as a freshwater resource.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gerard, R D; Worzel, J L</p> <p>1967-09-15</p> <p>A method is proposed whereby potable water may be obtained by condensing moisture from the atmosphere in suitable seashore or island areas. Deep, cold, offshore seawater is used as a source of cold and is pumped to condensers set up on shore to intercept the flow of highly humid, tropical, maritime <span class="hlt">air</span> <span class="hlt">masses</span>. This <span class="hlt">air</span>, when cooled, condenses moisture, which is conducted away and stored for use as a water supply. Windmill-driven generators would supply low-cost power for the operation. Side benefits are derived by using the nutritious deep water to support aquiculture in nearby lagoons or to enhance the productivity of the outfall area. Additional benefits are derived from the condenser as an <span class="hlt">air</span>-conditioning device for nearby residents. The islands of the Caribbean are used as an example of a location in the trade-winds belt where nearly optimum conditions for the operation of this system can be found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030062089','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030062089"><span>Fuel Cell Propulsion Systems for an All-electric Personal <span class="hlt">Air</span> Vehicle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kohout, Lisa L.; Schmitz, Paul C.</p> <p>2003-01-01</p> <p>There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton <span class="hlt">exchange</span> membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal <span class="hlt">air</span> vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem <span class="hlt">mass</span>, fuel storage volume and <span class="hlt">mass</span>, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton <span class="hlt">exchange</span> membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a <span class="hlt">mass</span> and range basis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030108305','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030108305"><span>Fuel Cell Propulsion Systems for an All-Electric Personal <span class="hlt">Air</span> Vehicle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kohout, Lisa L.</p> <p>2003-01-01</p> <p>There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton <span class="hlt">exchange</span> membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal <span class="hlt">air</span> vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem <span class="hlt">mass</span>, fuel storage volume and <span class="hlt">mass</span>, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton <span class="hlt">exchange</span> membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a <span class="hlt">mass</span> and range basis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2151844','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2151844"><span>Remote <span class="hlt">Mass</span> Spectrometric Sampling of Electrospray- and Desorption Electrospray-Generated Ions Using an <span class="hlt">Air</span> Ejector</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dixon, R. Brent; Bereman, Michael S.; Muddiman, David C.; Hawkridge, Adam M.</p> <p>2007-01-01</p> <p>A commercial <span class="hlt">air</span> ejector was coupled to an electrospray ionization linear ion trap <span class="hlt">mass</span> spectrometer (LTQ) to transport remotely generated ions from both electrospray (ESI) and desorption electrospray ionization (DESI) sources. We demonstrate the remote analysis of a series of analyte ions that range from small molecules and polymers to polypeptides using the AE-LTQ interface. The details of the ESI-AE-LTQ and DESI-AE-LTQ experimental configurations are described and preliminary <span class="hlt">mass</span> spectrometric data is presented. PMID:17716909</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930039263&hterms=air+measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dair%2Bmeasurement','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930039263&hterms=air+measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dair%2Bmeasurement"><span><span class="hlt">Air-mass</span> flux measurement system using Doppler-shifted filtered Rayleigh scattering</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shirley, John A.; Winter, Michael</p> <p>1993-01-01</p> <p>An optical system has been investigated to measure <span class="hlt">mass</span> flux distributions in the inlet of a high speed <span class="hlt">air</span>-breathing propulsion system. Rayleigh scattered light from <span class="hlt">air</span> is proportional to the number density of molecules and hence can be used to ascertain the gas density in a calibrated system. Velocity field measurements are achieved by spectrally filtering the elastically-scattered Doppler-shifted light with an absorbing molecular filter. A novel anamorphic optical collection system is used which allows optical rays from different scattering angles, that have different Doppler shifts, to be recorded separately. This is shown to obviate the need to tune the laser through the absorption to determine velocities, while retaining the ability to make spatially-resolved measurements along a line. By properly selecting the laser tuning and filter parameters, simultaneous density measurements can be made. These properties are discussed in the paper and experiments demonstrating the velocimetry capability are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870015088','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870015088"><span>Distributed control using linear momentum <span class="hlt">exchange</span> devices</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sharkey, J. P.; Waites, Henry; Doane, G. B., III</p> <p>1987-01-01</p> <p>MSFC has successfully employed the use of the Vibrational Control of Space Structures (VCOSS) Linear Momentum <span class="hlt">Exchange</span> Devices (LMEDs), which was an outgrowth of the <span class="hlt">Air</span> Force Wright Aeronautical Laboratory (AFWAL) program, in a distributed control experiment. The control experiment was conducted in MSFC's Ground Facility for Large Space Structures Control Verification (GF/LSSCV). The GF/LSSCV's test article was well suited for this experiment in that the LMED could be judiciously placed on the ASTROMAST. The LMED placements were such that vibrational mode information could be extracted from the accelerometers on the LMED. The LMED accelerometer information was processed by the control algorithms so that the LMED <span class="hlt">masses</span> could be accelerated to produce forces which would dampen the vibrational modes of interest. Experimental results are presented showing the LMED's capabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910014924&hterms=para+ortho+hydrogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpara%2Bortho%2Bhydrogen','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910014924&hterms=para+ortho+hydrogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpara%2Bortho%2Bhydrogen"><span>Cryogenic hydrogen-induced <span class="hlt">air</span> liquefaction technologies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Escher, William J. D.</p> <p>1990-01-01</p> <p>Extensively utilizing a special advanced airbreathing propulsion archives database, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen-induced <span class="hlt">air</span> liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented. The resulting assessment report is summarized. Technical findings are presented relating the status of <span class="hlt">air</span> liquefaction technology, both as a singular technical area, and also that of a cluster of collateral technical areas including: compact lightweight cryogenic heat <span class="hlt">exchangers</span>; heat <span class="hlt">exchanger</span> atmospheric constituents fouling alleviation; para/ortho hydrogen shift conversion catalysts; hydrogen turbine expanders, cryogenic <span class="hlt">air</span> compressors and liquid <span class="hlt">air</span> pumps; hydrogen recycling using slush hydrogen as heat sink; liquid hydrogen/liquid <span class="hlt">air</span> rocket-type combustion devices; <span class="hlt">air</span> collection and enrichment systems (ACES); and technically related engine concepts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.5912J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.5912J"><span>Modeling of water <span class="hlt">masses</span> <span class="hlt">exchange</span> between Brepolen and the main fjord in the Western Svalbard fjord - Hornsund</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jakacki, Jaromir; Przyborska, Anna; Sunfjord, Arild; Albertsen, Jon; Białoskórski, Michał; Pliszka, Bartosz</p> <p>2016-04-01</p> <p>Hornsund is the southernmost fjord of the Svalbard archipelago island - Spitsbergen. It is under the influence of two main currents - the coastal Sørkapp Current (SC) carrying fresher and colder water <span class="hlt">masses</span> from the Barents Sea and the West Spitsbergen Current (WSC), which is the branch of the Norwegian Atlantic Current (NwAC) and carries warm and salty waters from the North Atlantic. The main local forcing, which is tidal motion, brings shelf waters into the central fjord basin and then the transformed <span class="hlt">masses</span> are carried into the easternmost part of the fjord, Brepolen. For the purpose of studying circulation and water <span class="hlt">exchange</span> in this area a three-dimensional hydrodynamic model has been implemented and validated. The model is based on MIKE by DHI product and covers the Hornsund fjord with the shelf area, which is the fjord foreground. It is sigma a coordinate model (in our case 35 vertical levels) with variable horizontal resolution (mesh grid). The smallest cell has a horizontal dimension less than one hundred meters and the largest cells about 5 km. In spite of model limitations, the model reproduces the main circulation and water pathways in the Brepolen area. Seasonal and annual volume, heat and salt <span class="hlt">exchanges</span> have been also estimated. The influence of freshwater discharge on shelf-fjord <span class="hlt">exchange</span> will be also analyzed. The model results allow to study full horizontal and vertical fields of physical parameters (temperature, salinity, sea level variations and currents). The model integration covers only years 2005-2010 and the presented results will be based on this simulation. The project has been financed from the funds of the Leading National Research Centre (KNOW) received by the Centre for Polar Studies for the period 2014-2018</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015HMT....51.1121T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015HMT....51.1121T"><span>Estimation of whole lemon <span class="hlt">mass</span> transfer parameters during hot <span class="hlt">air</span> drying using different modelling methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torki-Harchegani, Mehdi; Ghanbarian, Davoud; Sadeghi, Morteza</p> <p>2015-08-01</p> <p>To design new dryers or improve existing drying equipments, accurate values of <span class="hlt">mass</span> transfer parameters is of great importance. In this study, an experimental and theoretical investigation of drying whole lemons was carried out. The whole lemons were dried in a convective hot <span class="hlt">air</span> dryer at different <span class="hlt">air</span> temperatures (50, 60 and 75 °C) and a constant <span class="hlt">air</span> velocity (1 m s-1). In theoretical consideration, three moisture transfer models including Dincer and Dost model, Bi- G correlation approach and conventional solution of Fick's second law of diffusion were used to determine moisture transfer parameters and predict dimensionless moisture content curves. The predicted results were then compared with the experimental data and the higher degree of prediction accuracy was achieved by the Dincer and Dost model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24047550','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24047550"><span>Polycyclic aromatic hydrocarbons in surface soil across the Tibetan Plateau: spatial distribution, source and <span class="hlt">air</span>-soil <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Chuanfei; Wang, Xiaoping; Gong, Ping; Yao, Tandong</p> <p>2014-01-01</p> <p>There are limited data on polycyclic aromatic hydrocarbons (PAHs) in both the atmosphere and soil of the Tibetan Plateau (TP). Concentrations of PAHs were therefore measured in 13 XAD resin-based passive <span class="hlt">air</span> samplers and 41 surface (0-5 cm) soil samples across the TP. The average concentration of atmospheric PAHs was 5.55 ng/m(3), which was lower than that reported for other background areas, but higher than the Arctic. Concentrations in the soils fell in a wide range from 5.54 to 389 ng/g, with an average of 59.9 ng/g. Elevation was found to play an important role in determining the spatial distribution of soil PAHs. The <span class="hlt">air</span>-soil <span class="hlt">exchange</span> state showed that the soils of the TP will likely remain as a sink for high molecular weight PAHs, but may become a potential "secondary source" for low molecular weight PAHs. Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=327584','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=327584"><span>Toward a better understanding of the impact of <span class="hlt">mass</span> transit <span class="hlt">air</span> pollutants on human health</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Modern <span class="hlt">mass</span> transit systems, based on roads, rail, water, and <span class="hlt">air</span>, generate toxic airborne pollutants throughout the developed world. This has become one of the leading concerns about the use of modern transportation, particularly in densely-populated urban areas where their use is enormous and inc...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ACP.....6.5649M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ACP.....6.5649M"><span>Cluster Analysis of the Organic Peaks in Bulk <span class="hlt">Mass</span> Spectra Obtained During the 2002 New England <span class="hlt">Air</span> Quality Study with an Aerodyne Aerosol <span class="hlt">Mass</span> Spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marcolli, C.; Canagaratna, M. R.; Worsnop, D. R.; Bahreini, R.; de Gouw, J. A.; Warneke, C.; Goldan, P. D.; Kuster, W. C.; Williams, E. J.; Lerner, B. M.; Roberts, J. M.; Meagher, J. F.; Fehsenfeld, F. C.; Marchewka, M.; Bertman, S. B.; Middlebrook, A. M.</p> <p>2006-12-01</p> <p>We applied hierarchical cluster analysis to an Aerodyne aerosol <span class="hlt">mass</span> spectrometer (AMS) bulk <span class="hlt">mass</span> spectral dataset collected aboard the NOAA research vessel R. H. Brown during the 2002 New England <span class="hlt">Air</span> Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their <span class="hlt">mass</span> spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter probably originating from both anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when <span class="hlt">air</span> <span class="hlt">masses</span> from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent on average 17% of the total organic <span class="hlt">mass</span> that stems likely from biogenic sources during the ship's cruise. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated <span class="hlt">mass</span> spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol <span class="hlt">mass</span> spectra from a field study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25501714','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25501714"><span>Characterization of ion processes in a GC/DMS <span class="hlt">air</span> quality monitor by integration of the instrument to a <span class="hlt">mass</span> spectrometer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Limero, T F; Nazarov, E G; Menlyadiev, M; Eiceman, G A</p> <p>2015-02-07</p> <p>The <span class="hlt">air</span> quality monitor (AQM), which included a portable gas chromatograph (GC) and a detector was interfaced to a <span class="hlt">mass</span> spectrometer (MS) by introducing flow from the GC detector to the atmospheric pressure ion source of the MS. This small GC system, with a gas recirculation loop for carrier and detector make-up gases, comprised an inlet to preconcentrate volatile organic compounds (VOCs) in <span class="hlt">air</span>, a thermal desorber before the GC column, a differential mobility spectrometer (DMS), and another DMS as an atmospheric pressure ionization source for the MS. Return flow to the internally recirculated <span class="hlt">air</span> system of the AQM's DMS was replenished using purified <span class="hlt">air</span>. Although ions and unreacted neutral vapors flowed from the detector through Viton® tubing into the source of the MS, ions were not detected in the MS without the auxillary ion source, (63)Ni as in the mobility detector. The GC-DMS-MS instrument provided a 3-D measurement platform (GC, DMS, and MS analysis) to explore the gas composition inside the GC-DMS recirculation loop and provide DMS-MS measurement of the components of a complex VOC mixture with performance significantly enhanced by <span class="hlt">mass</span>-analysis, either with <span class="hlt">mass</span> spectral scans or with an extracted ion chromatogram. This combination of a mobility spectrometer and a <span class="hlt">mass</span> spectrometer was possible as vapors and ions are carried together through the DMS analyzer, thereby preserving the chromatographic separation efficiency. The critical benefit of this instrument concept is that all flows in and through the thoroughly integrated GC-DMS analyzer are kept intact allowing a full measure of the ion and vapor composition in the complete system. Performance has been evaluated using a synthetic <span class="hlt">air</span> sample and a sample of airborne vapors in a laboratory. Capabilities and performance values are described using results from AQM-MS analysis of purified <span class="hlt">air</span>, ambient <span class="hlt">air</span> from a research laboratory in a chemistry building, and a sample of synthetic <span class="hlt">air</span> of known composition</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ACPD....6.4601M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ACPD....6.4601M"><span>Cluster analysis of the organic peaks in bulk <span class="hlt">mass</span> spectra obtained during the 2002 New England <span class="hlt">Air</span> Quality Study with an Aerodyne aerosol <span class="hlt">mass</span> spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marcolli, C.; Canagaratna, M. R.; Worsnop, D. R.; Bahreini, R.; de Gouw, J. A.; Warneke, C.; Goldan, P. D.; Kuster, W. C.; Williams, E. J.; Lerner, B. M.; Roberts, J. M.; Meagher, J. F.; Fehsenfeld, F. C.; Marchewka, M. L.; Bertman, S. B.; Middlebrook, A. M.</p> <p>2006-06-01</p> <p>We applied hierarchical cluster analysis to an Aerodyne aerosol <span class="hlt">mass</span> spectrometer (AMS) bulk <span class="hlt">mass</span> spectral dataset collected aboard the NOAA research vessel Ronald H. Brown during the 2002 New England <span class="hlt">Air</span> Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their <span class="hlt">mass</span> spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter most probably originating from both, anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when <span class="hlt">air</span> <span class="hlt">masses</span> from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent as much as 5 µg/m3 organic aerosol <span class="hlt">mass</span> - 17% of the total organic <span class="hlt">mass</span> - that can be attributed to biogenic sources. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated <span class="hlt">mass</span> spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol <span class="hlt">mass</span> spectra from a field study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.......189H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.......189H"><span>Heat Transfer in Metal Foam Heat <span class="hlt">Exchangers</span> at High Temperature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hafeez, Pakeeza</p> <p></p> <p>Heat transfer though open-cell metal foam is experimentally studied for heat <span class="hlt">exchanger</span> and heat shield applications at high temperatures (˜750°C). Nickel foam sheets with pore densities of 10 and 40 pores per linear inch (PPI), have been used to make the heat <span class="hlt">exchangers</span> and heat shields by using thermal spray coating to deposit an Inconel skin on a foam core. Heat transfer measurements were performed on a test rig capable of generating hot gas up to 1000°C. The heat <span class="hlt">exchangers</span> were tested by exposing their outer surface to combustion gases at a temperature of 550°C and 750°C while being cooled by <span class="hlt">air</span> flowing through them at room temperature at velocities up to 5 m/s. The temperature rise of the <span class="hlt">air</span>, the surface temperature of the heat <span class="hlt">exchangers</span> and the <span class="hlt">air</span> temperature inside the heat <span class="hlt">exchanger</span> were measured. The volumetric heat transfer coefficient and Nusselt number were calculated for different velocities. The heat transfer performance of the 40PPI sample brazed with the foil is found to be the most efficient. Pressure drop measurements were also performed for 10 and 40PPI metal foam. Thermographic measurements were done on 40PPI foam heat <span class="hlt">exchangers</span> using a high temperature infrared camera. A high power electric heater was used to produce hot <span class="hlt">air</span> at 300°C that passed over the foam heat <span class="hlt">exchanger</span> while the cooling <span class="hlt">air</span> was blown through it. Heat shields were made by depositing porous skins on metal foam and it was observed that a small amount of coolant leaking through the pores notably reduces the heat transfer from the hot gases. An analytical model was developed based assuming local thermal non-equilibrium that accounts for the temperature difference between solid and fluid phase. The experimental results are found to be in good agreement with the predicted values of the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1570919','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1570919"><span>Structure, function and evolution of the gas <span class="hlt">exchangers</span>: comparative perspectives</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Maina, JN</p> <p>2002-01-01</p> <p>Over the evolutionary continuum, animals have faced similar fundamental challenges of acquiring molecular oxygen for aerobic metabolism. Under limitations and constraints imposed by factors such as phylogeny, behaviour, body size and environment, they have responded differently in founding optimal respiratory structures. A quintessence of the aphorism that ‘necessity is the mother of invention’, gas <span class="hlt">exchangers</span> have been inaugurated through stiff cost–benefit analyses that have evoked transaction of trade-offs and compromises. Cogent structural–functional correlations occur in constructions of gas <span class="hlt">exchangers</span>: within and between taxa, morphological complexity and respiratory efficiency increase with metabolic capacities and oxygen needs. Highly active, small endotherms have relatively better-refined gas <span class="hlt">exchangers</span> compared with large, inactive ectotherms. Respiratory structures have developed from the plain cell membrane of the primeval prokaryotic unicells to complex multifunctional ones ofthe modern Metazoa. Regarding the respiratory medium used to extract oxygen from, animal life has had only two choices – water or <span class="hlt">air</span> – within the biological range of temperature and pressure the only naturally occurring respirable fluids. In rarer cases, certain animalshave adapted to using both media. Gills (evaginated gas <span class="hlt">exchangers</span>) are the primordial respiratory organs: they are the archetypal water breathing organs. Lungs (invaginated gas <span class="hlt">exchangers</span>) are the model <span class="hlt">air</span> breathing organs. Bimodal (transitional) breathers occupy the water–<span class="hlt">air</span> interface. Presentation and exposure of external (water/<span class="hlt">air</span>) and internal (haemolymph/blood) respiratory media, features determined by geometric arrangement of the conduits, are important features for gas <span class="hlt">exchange</span> efficiency: counter-current, cross-current, uniform pool and infinite pool designs have variably developed. PMID:12430953</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008cosp...37.3319V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008cosp...37.3319V"><span>Closure of <span class="hlt">mass</span> <span class="hlt">exchange</span> under use of a vegetable conveyer cultivated on a neutral and soil-like substrates as applied to BLSS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Velitchko, Vladimir; Tikhomirov, Alexander; Ushakova, Sofya</p> <p></p> <p>To increase a closure level of <span class="hlt">mass</span> <span class="hlt">exchange</span> processes in bioregenerative life support systems (BLSS) including a human a technology of plants cultivation on a soil-like substrate (SLS) consisting in a gradual decomposition of inedible plants biomass under its addition in the SLS was developed at the Institute of Biophysics SB RAS (Russia). In the given work the effect of periodical introduction of inedible plant biomass in the SLS on plants photosynthetic productivity and on the closure of <span class="hlt">mass</span> <span class="hlt">exchange</span> has been analyzed. Thereupon CO2 gas <span class="hlt">exchange</span> and the certain vegetables' productivity under their cultivation in a conveyor regime on the SLS and on a neutral substrate with reference to the closure of <span class="hlt">mass</span> <span class="hlt">exchange</span> processes in BLSS have been studied in this work. The vegetables Raphanus sativus L., Brassica caulorapa L. Daucus carota L. and Beta vulgaris L. being prospective plantsrepresentatives of the BLSS phototrophic unit were taken as the research objects. The SLS was taken as an experiment substrate and an expanded clay aggregate as the control. The changeable Knop solution was used for the control, and an irrigation solution with the SLS extract was used for the experiment. Rapidity dynamics of CO2 consumption showed sharp distinctions of the ‘plants-SLS' system from the ‘plantsexpanded clay aggregate' system connected with the oxidation processes coursing in the SLS. The intensity of CO2 evolution from the SLS on average was 70% of the total plants conveyor's respiration. Thus a balance between the system's respiration and photosynthesis was often determined by the processes coursing in the SLS. Here the sharp CO2 evolution was recorded after introduction of the plants inedible biomass in the SLS. That peak was gradually coming down during 10-14 days after the beginning of every cycle of plants cultivation that was connected with intensification of plants photosynthesis and drop of decomposition intensity of the biomass introduced. Comparative</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100040574&hterms=common+good&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcommon%2Bgood','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100040574&hterms=common+good&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcommon%2Bgood"><span>International Space Station Common Cabin <span class="hlt">Air</span> Assembly Condensing Heat <span class="hlt">Exchanger</span> Hydrophilic Coating Failures and Lessons Learned</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Balistreri, Steven F.; Shaw, Laura A.; Laliberte, Yvon</p> <p>2010-01-01</p> <p>The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin <span class="hlt">air</span> is controlled by the Common Cabin <span class="hlt">Air</span> Assembly (CCAA). The CCAA consists of a fan, a condensing heat <span class="hlt">exchanger</span> (CHX), an <span class="hlt">air</span>/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent <span class="hlt">air</span>. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX, the unit s ability to remove moisture from the <span class="hlt">air</span> is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within in the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings and potential remediation techniques will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.B21E..06W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.B21E..06W"><span>Spatial and Temporal Patterns in the Carbon Isotopic Signal of Leaf Wax Aerosols in Continental <span class="hlt">Air</span> <span class="hlt">Masses</span>: Linkages with Ecosystem Discrimination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weber, J.; Conte, M. H.</p> <p>2006-12-01</p> <p>Temporal and spatial variations in the concentration and isotopic composition of atmospheric carbon dioxide can be used to estimate the relative magnitudes of the terrestrial and oceanic carbon sinks. An important model parameter is the terrestrial photosynthetic carbon isotopic fractionation of CO2 (Δ), yet estimating Δ over the large spatial scales required by models remains problematic. Epiculticular leaf waxes appear to closely reflect the plant's carbon isotopic discrimination; therefore, the ablated wax aerosols present in well-mixed continental <span class="hlt">air</span> <span class="hlt">masses</span> may be used as a proxy to estimate the magnitude of Δ integrated over large (subcontinental) spatial scales. Over the last several years, we have been conducting time-series studies of wax aerosol molecular and isotopic composition at strategically located sites (Maine, northern Alaska, Florida, Bermuda, Barbados) which receive continental <span class="hlt">air</span> <span class="hlt">masses</span> passing over major terrestrial biomes (northern temperate/ecotonal boreal forests, tundra, southern US pine/hardwood forests, North American and north African). In this presentation, we describe and contrast patterns of wax aerosol-derived estimates of Δ at these sites. In North American <span class="hlt">air</span> <span class="hlt">masses</span>, estimates of Δ range from 14.5-20.5 using the concentration-weighted average δ13C of wax n-acids and from 13.5-19.5 for the wax n-alcohols. Seasonal trends observed in the Florida (southern US) and Bermuda samples (mixed North American <span class="hlt">air</span> <span class="hlt">masses</span>) indicate maximum discrimination in early spring and minimum discrimination during the summer dry season. In northern US and high latitude <span class="hlt">air</span> <span class="hlt">masses</span>, seasonal trends are less pronounced but in general temporally offset with highest discrimination occurring during late summer. At Barbados, which is dominated by north African <span class="hlt">air</span> <span class="hlt">masses</span> passing over regions largely comprised of arid C4 grasslands, estimated Δ for the wax n-acids is significantly lower (14.0-15.5 per mil), consistent with a higher predominance of C4</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/11366','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/11366"><span>A Controlled Environment System For Measuring Plant-Atmosphere Gas <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>James M. Brown</p> <p>1975-01-01</p> <p>Describes an inexpensive, efficient system for measuring plant-atmosphere gas <span class="hlt">exchange</span>. Designed to measure transpiration from potted tree seedlings, it is readily adaptable for measuring other gas <span class="hlt">exchanges</span> or gas <span class="hlt">exchange</span> by plant parts. Light level, <span class="hlt">air</span> and root temperature can be precisely controlled at minimum cost.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E3339T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E3339T"><span>Inclusion of human mineralized exometabolites and fish wastes as a source of higher plant mineral nutrition in BTLSS <span class="hlt">mass</span> <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tikhomirova, Natalia; Tikhomirov, Alexander A.; Ushakova, Sofya; Anischenko, Olesya; Trifonov, Sergey V.</p> <p></p> <p>Human exometabolites inclusion into an intrasystem <span class="hlt">mass</span> <span class="hlt">exchange</span> will allow increasing of a closure level of a biological-technical life support system (BTLSS). Previously at the IBP SB RAS it was shown that human mineralized exometabolites could be incorporated in the BTLSS <span class="hlt">mass</span> <span class="hlt">exchange</span> as a mineral nutrition source for higher plants. However, it is not known how that combined use of human mineralized exometabolites and fish wastes in the capacity of nutrient medium, being a part of the BTLSS consumer wastes, will affect the plant productivity. Several wheat vegetations were grown in an uneven-aged conveyor on a neutral substrate. A mixture of human mineralized exometabolites and fish wastes was used as a nutrient solution in the experiment treatment and human mineralized exometabolites were used in the control. Consequently, a high wheat yield in the experiment treatment practically equal to the control yield was obtained. Thus, mineralized fish wastes can be an additional source of macro-and micronutrients for plants, and use of such wastes for the plant mineral nutrition allows increasing of BTLSS closure level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15037083','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15037083"><span>Equilibrium and kinetic folding of rabbit muscle triosephosphate isomerase by hydrogen <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pan, Hai; Raza, Ashraf S; Smith, David L</p> <p>2004-03-05</p> <p>Unfolding and refolding of rabbit muscle triosephosphate isomerase (TIM), a model for (betaalpha)8-barrel proteins, has been studied by amide hydrogen <span class="hlt">exchange/mass</span> spectrometry. Unfolding was studied by destabilizing the protein in guanidine hydrochloride (GdHCl) or urea, pulse-labeling with 2H2O and analyzing the intact protein by HPLC electrospray ionization <span class="hlt">mass</span> spectrometry. Bimodal isotope patterns were found in the <span class="hlt">mass</span> spectra of the labeled protein, indicating two-state unfolding behavior. Refolding experiments were performed by diluting solutions of TIM unfolded in GdHCl or urea and pulse-labeling with 2H2O at different times. <span class="hlt">Mass</span> spectra of the intact protein labeled after one to two minutes had three envelopes of isotope peaks, indicating population of an intermediate. Kinetic modeling indicates that the stability of the folding intermediate in water is only 1.5 kcal/mol. Failure to detect the intermediate in the unfolding experiments was attributed to its low stability and the high concentrations of denaturant required for unfolding experiments. The folding status of each segment of the polypeptide backbone was determined from the deuterium levels found in peptic fragments of the labeled protein. Analysis of these spectra showed that the C-terminal half folds to form the intermediate, which then forms native TIM with folding of the N-terminal half. These results show that TIM folding fits the (4+4) model for folding of (betaalpha)8-barrel proteins. Results of a double-jump experiment indicate that proline isomerization does not contribute to the rate-limiting step in the folding of TIM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25825865','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25825865"><span>Infrequent <span class="hlt">air</span> contamination with Acinetobacter baumannii of <span class="hlt">air</span> surrounding known colonized or infected patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rock, Clare; Harris, Anthony D; Johnson, J Kristie; Bischoff, Werner E; Thom, Kerri A</p> <p>2015-07-01</p> <p>Using a validated <span class="hlt">air</span> sampling method we found Acinetobacter baumannii in the <span class="hlt">air</span> surrounding only 1 of 12 patients known to be colonized or infected with A. baumannii. Patients' closed-circuit ventilator status, frequent <span class="hlt">air</span> <span class="hlt">exchanges</span> in patient rooms, and short sampling time may have contributed to this low burden.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910000544&hterms=Air+conditioning+system&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DAir%2Bconditioning%2Bsystem','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910000544&hterms=Air+conditioning+system&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DAir%2Bconditioning%2Bsystem"><span>Expert System For Heat <span class="hlt">Exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bagby, D. Gordon; Cormier, Reginald A.</p> <p>1991-01-01</p> <p>Diagnosis simplified for non-engineers. Developmental expert-system computer program assists operator in controlling, monitoring operation, diagnosing malfunctions, and ordering repairs of heat-<span class="hlt">exchanger</span> system dissipating heat generated by 20-kW radio transmitter. System includes not only heat <span class="hlt">exchanger</span> but also pumps, fans, sensors, valves, reservoir, and associated plumbing. Program conceived to assist operator while avoiding cost of keeping engineer in full-time attendance. Similar programs developed for heating, ventilating, and <span class="hlt">air</span>-conditioning systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863488','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863488"><span>Fluidized bed heat <span class="hlt">exchanger</span> utilizing angularly extending heat <span class="hlt">exchange</span> tubes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Talmud, Fred M.; Garcia-Mallol, Juan-Antonio</p> <p>1980-01-01</p> <p>A fluidized bed heat <span class="hlt">exchanger</span> in which <span class="hlt">air</span> is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided and includes a steam drum disposed adjacent the fluidized bed and a series of tubes connected at one end to the steam drum. A portion of the tubes are connected to a water drum and in the path of the <span class="hlt">air</span> and the gaseous products of combustion exiting from the bed. Another portion of the tubes pass through the bed and extend at an angle to the upper surface of the bed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910013846&hterms=para+ortho+hydrogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpara%2Bortho%2Bhydrogen','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910013846&hterms=para+ortho+hydrogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpara%2Bortho%2Bhydrogen"><span>Cryogenic hydrogen-induced <span class="hlt">air</span>-liquefaction technologies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Escher, William J. D.</p> <p>1990-01-01</p> <p>Extensive use of a special advanced airbreathing propulsion archives data base, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen induced <span class="hlt">air</span> liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented in 1986. The resulting assessment report is summarized. Technical findings relating the status of <span class="hlt">air</span> liquefaction technology are presented both as a singular technical area, and also as that of a cluster of collateral technical areas including: Compact lightweight cryogenic heat <span class="hlt">exchangers</span>; Heat <span class="hlt">exchanger</span> atmospheric constituents fouling alleviation; Para/ortho hydrogen shift conversion catalysts; Hydrogen turbine expanders, cryogenic <span class="hlt">air</span> compressors and liquid <span class="hlt">air</span> pumps; Hydrogen recycling using slush hydrogen as heat sinks; Liquid hydrogen/liquid <span class="hlt">air</span> rocket type combustion devices; <span class="hlt">Air</span> Collection and Enrichment System (ACES); and Technically related engine concepts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10535149','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10535149"><span>Indoor <span class="hlt">air</span> quality at the Correr Museum, Venice, Italy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Camuffo, D; Brimblecombe, P; Van Grieken, R; Busse, H J; Sturaro, G; Valentino, A; Bernardi, A; Blades, N; Shooter, D; De Bock, L; Gysels, K; Wieser, M; Kim, O</p> <p>1999-09-15</p> <p>Two multidisciplinary field surveys, one in winter and the other in summer have monitored the indoor microclimate, <span class="hlt">air</span> pollution, deposition and origin of the suspended particulate matter and microorganisms of the Correr Museum, Venice. In addition, this study was focused to identify the problems caused by the heating and <span class="hlt">air</span> conditioning system (HAC) and the effects due to the presence of carpets. Heating and <span class="hlt">air</span> conditioning systems (HACs), when chiefly designed for human welfare, are not suitable for conservation and can cause dangerous temperature and humidity fluctuations. Improvements at the Correr Museum have been achieved with the assistance of environmental monitoring. The carpet has a negative influence as it retains particles and bacteria which are resuspended each time people walk on it. The indoor/outdoor pollutants ratio is greater in the summertime, when doors and windows are more frequently open to allow for better ventilation, illustrating that this ratio is mainly governed by the free <span class="hlt">exchange</span> of the <span class="hlt">air</span> <span class="hlt">masses</span>. The chemical composition, size and origin of the suspended particulate matter have been identified, as well as the bacteria potentially dangerous to the paintings. Some general suggestions for improving indoor <span class="hlt">air</span> quality are reported in the conclusions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvC..97d5502B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvC..97d5502B"><span>Quasielastic neutrino charged-current scattering off 12C: Effects of the meson <span class="hlt">exchange</span> currents and large nucleon axial <span class="hlt">mass</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butkevich, A. V.; Luchuk, S. V.</p> <p>2018-04-01</p> <p>The quasielastic scattering of muon neutrino and electrons on a carbon target are analyzed using the relativistic distorted-wave impulse approximation (RDWIA). We also evaluate the contribution of the two-particle and two-hole meson <span class="hlt">exchange</span> current (2 p -2 h MEC) to electroweak response functions. The nuclear model dependence of the (anti)neutrino cross sections is studied within the RDWIA+MEC approach and RDWIA model with the large nucleon axial <span class="hlt">mass</span>. It is shown that the results for the squared momentum transfer distribution d σ /d Q2 and for invariant <span class="hlt">mass</span> of the final hadronic system distribution d σ /d W obtained within these models are substantially different.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23197791','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23197791"><span>Nepenthesin from monkey cups for hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rey, Martial; Yang, Menglin; Burns, Kyle M; Yu, Yaping; Lees-Miller, Susan P; Schriemer, David C</p> <p>2013-02-01</p> <p>Studies of protein dynamics, structure and interactions using hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) have sharply increased over the past 5-10 years. The predominant technology requires fast digestion at pH 2-3 to retain deuterium label. Pepsin is used almost exclusively, but it provides relatively low efficiency under the constraints of the experiment, and a selectivity profile that renders poor coverage of intrinsically disordered regions. In this study we present nepenthesin-containing secretions of the pitcher plant Nepenthes, commonly called monkey cups, for use in HDX-MS. We show that nepenthesin is at least 1400-fold more efficient than pepsin under HDX-competent conditions, with a selectivity profile that mimics pepsin in part, but also includes efficient cleavage C-terminal to "forbidden" residues K, R, H, and P. High efficiency permits a solution-based analysis with no detectable autolysis, avoiding the complication of immobilized enzyme reactors. Relaxed selectivity promotes high coverage of disordered regions and the ability to "tune" the <span class="hlt">mass</span> map for regions of interest. Nepenthesin-enriched secretions were applied to an analysis of protein complexes in the nonhomologous end-joining DNA repair pathway. The analysis of XRCC4 binding to the BRCT domains of Ligase IV points to secondary interactions between the disordered C-terminal tail of XRCC4 and remote regions of the BRCT domains, which could only be identified with a nepenthesin-based workflow. HDX data suggest that stalk-binding to XRCC4 primes a BRCT conformation in these remote regions to support tail interaction, an event which may be phosphoregulated. We conclude that nepenthesin is an effective alternative to pepsin for all HDX-MS applications, and especially for the analysis of structural transitions among intrinsically disordered proteins and their binding partners.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16106855','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16106855"><span>Analysis of carbohydrates by anion <span class="hlt">exchange</span> chromatography and <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bruggink, Cees; Maurer, Rolf; Herrmann, Heiko; Cavalli, Silvano; Hoefler, Frank</p> <p>2005-08-26</p> <p>A versatile liquid chromatographic platform has been developed for analysing underivatized carbohydrates using high performance anion <span class="hlt">exchange</span> chromatography (HPAEC) followed by an inert PEEK splitter that splits the effluent to the integrated pulsed amperometric detector (IPAD) and to an on-line single quadrupole <span class="hlt">mass</span> spectrometer (MS). Common eluents for HPAEC such as sodium hydroxide and sodium acetate are beneficial for the amperometric detection but not compatible with electrospray ionisation (ESI). Therefore a membrane-desalting device was installed after the splitter and prior to the ESI interface converting sodium hydroxide into water and sodium acetate into acetic acid. To enhance the sensitivity for the MS detection, 0.5 mmol/l lithium chloride was added after the membrane desalter to form lithium adducts of the carbohydrates. To compare sensitivity of IPAD and MS detection glucose, fructose, and sucrose were used as analytes. A calibration with external standards from 2.5 to 1000 pmole was performed showing a linear range over three orders of magnitude. Minimum detection limits (MDL) with IPAD were determined at 5 pmole levels for glucose to be 0.12 pmole, fructose 0.22 pmole and sucrose 0.11 pmole. With MS detection in the selected ion mode (SIM) the lithium adducts of the carbohydrates were detected obtaining MDL's for glucose of 1.49 pmole, fructose 1.19 pmole, and sucrose 0.36 pmole showing that under these conditions IPAD is 3-10 times more sensitive for those carbohydrates. The applicability of the method was demonstrated analysing carbohydrates in real world samples such as chicory inulin where polyfructans up to a molecular <span class="hlt">mass</span> of 7000 g/mol were detected as quadrupoly charged lithium adducts. Furthermore mono-, di-, tri-, and oligosaccharides were detected in chicory coffee, honey and beer samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28178609','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28178609"><span>Toward a better understanding of the impact of <span class="hlt">mass</span> transit <span class="hlt">air</span> pollutants on human health.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Ki-Hyun; Kumar, Pawan; Szulejko, Jan E; Adelodun, Adedeji A; Junaid, Muhammad Faisal; Uchimiya, Minori; Chambers, Scott</p> <p>2017-05-01</p> <p>Globally, modern <span class="hlt">mass</span> transport systems whether by road, rail, water, or <span class="hlt">air</span> generate airborne pollutants in both developing and developed nations. <span class="hlt">Air</span> pollution is the primary human health concern originating from modern transportation, particularly in densely-populated urban areas. This review will specifically focus on the origin and the health impacts of carbonaceous traffic-related <span class="hlt">air</span> pollutants (TRAP), including particulate matter (PM), volatile organic compounds (VOCs), and elemental carbon (EC). We conclude that the greatest current challenge regarding urban TRAP is understanding and evaluating the human health impacts well enough to set appropriate pollution control measures. Furthermore, we provide a detailed discussion regarding the effects of TRAP on local environments and pedestrian health in low and high traffic-density environments. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25837315','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25837315"><span>Development of a particle-trap preconcentration-soft ionization <span class="hlt">mass</span> spectrometric technique for the quantification of mercury halides in <span class="hlt">air</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Deeds, Daniel A; Ghoshdastidar, Avik; Raofie, Farhad; Guérette, Élise-Andrée; Tessier, Alain; Ariya, Parisa A</p> <p>2015-01-01</p> <p>Measurement of oxidized mercury, Hg(II), in the atmosphere poses a significant analytical challenge as Hg(II) is present at ultra-trace concentrations (picograms per cubic meter <span class="hlt">air</span>). Current technologies are sufficiently sensitive to measure the total Hg present as Hg(II) but cannot determine the chemical speciation of Hg(II). We detail here the development of a soft ionization <span class="hlt">mass</span> spectrometric technique coupled with preconcentration onto nano- or microparticle-based traps prior to analysis for the measurement of mercury halides in <span class="hlt">air</span>. The current methodology has comparable detection limits (4-11 pg m(-3)) to previously developed techniques for the measurement of total inorganic mercury in <span class="hlt">air</span> while allowing for the identification of HgX2 in collected samples. Both mercury chloride and mercury bromide have been sporadically detected in Montreal urban and indoor <span class="hlt">air</span> using atmospheric pressure chemical ionization-<span class="hlt">mass</span> spectrometry (APCI-MS). We discuss limitations and advantages of the current technique and discuss potential avenues for future research including quantitative trace measurements of a larger range of mercury compounds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JTST...25.1056H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JTST...25.1056H"><span>Fabrication of High-Temperature Heat <span class="hlt">Exchangers</span> by Plasma Spraying Exterior Skins on Nickel Foams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hafeez, P.; Yugeswaran, S.; Chandra, S.; Mostaghimi, J.; Coyle, T. W.</p> <p>2016-06-01</p> <p>Thermal-sprayed heat <span class="hlt">exchangers</span> were tested at high temperatures (750 °C), and their performances were compared to the foam heat <span class="hlt">exchangers</span> made by brazing Inconel sheets to their surface. Nickel foil was brazed to the exterior surface of 10-mm-thick layers of 10 and 40 PPI nickel foam. A plasma torch was used to spray an Inconel coating on the surface of the foil. A burner test rig was built to produce hot combustion gases that flowed over exposed face of the heat <span class="hlt">exchanger</span>. Cooling <span class="hlt">air</span> flowed through the foam heat <span class="hlt">exchanger</span> at rates of up to 200 SLPM. Surface temperature and <span class="hlt">air</span> inlet/exit temperature were measured. Heat transfer to <span class="hlt">air</span> flowing through the foam was significantly higher for the thermally sprayed heat <span class="hlt">exchangers</span> than for the brazed heat <span class="hlt">exchangers</span>. On an average, thermally sprayed heat <span class="hlt">exchangers</span> show 36% higher heat transfer than conventionally brazed foam heat <span class="hlt">exchangers</span>. At low flow rates, the convective resistance is large (~4 × 10-2 m2 K/W), and the effect of thermal contact resistance is negligible. At higher flow rates, the convective resistance decreases (~2 × 10-3 m2 K/W), and the lower contact resistance of the thermally sprayed heat <span class="hlt">exchanger</span> provides better performance than the brazed heat <span class="hlt">exchangers</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGD....10.8415S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGD....10.8415S"><span>Biology and <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> controls on the distribution of carbon isotope ratios (δ13C) in the ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmittner, A.; Gruber, N.; Mix, A. C.; Key, R. M.; Tagliabue, A.; Westberry, T. K.</p> <p>2013-05-01</p> <p>Analysis of observations and sensitivity experiments with a new three-dimensional global model of stable carbon isotope cycling elucidate the processes that control the distribution of δ13C in the contemporary and preindustrial ocean. Biological fractionation dominates the distribution of δ13CDIC of dissolved inorganic carbon (DIC) due to the sinking of isotopically light δ13C organic matter from the surface into the interior ocean. This process leads to low δ13CDIC values at dephs and in high latitude surface waters and high values in the upper ocean at low latitudes with maxima in the subtropics. <span class="hlt">Air</span>-sea gas <span class="hlt">exchange</span> provides an important secondary influence due to two effects. First, it acts to reduce the spatial gradients created by biology. Second, the associated temperature dependent fractionation tends to increase (decrease) δ13CDIC values of colder (warmer) water, which generates gradients that oppose those arising from biology. Our model results suggest that both effects are similarly important in influencing surface and interior δ13CDIC distributions. However, <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> is slow, so biological effect dominate spatial δ13CDIC gradients both in the interior and at the surface, in constrast to conclusions from some previous studies. Analysis of a new synthesis of δ13CDIC measurements from years 1990 to 2005 is used to quantify preformed (δ13Cpre) and remineralized (δ13Crem) contributions as well as the effects of biology (Δδ13Cbio) and <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span> (δ13C*). The model reproduces major features of the observed large-scale distribution of δ13CDIC, δ13Cpre, δ13Crem, δ13C*, and Δδ13Cbio. Residual misfits are documented and analyzed. Simulated surface and subsurface δ13CDIC are influenced by details of the ecosystem model formulation. For example, inclusion of a simple parameterization of iron limitation of phytoplankton growth rates and temperature-dependent zooplankton grazing rates improves the agreement with δ13CDIC</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22648347','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22648347"><span>Seasonal and <span class="hlt">air</span> <span class="hlt">mass</span> trajectory effects on dissolved organic matter of bulk deposition at a coastal town in south-western Europe.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santos, Patrícia S M; Santos, Eduarda B H; Duarte, Armando C</p> <p>2013-01-01</p> <p>Rainwater contains a complex mixture of organic compounds which may influence climate, terrestrial and maritime ecosystems and thus human health. In this work, the characteristics of DOM of bulk deposition at a coastal town on the southwest of Europe were assessed by UV-visible and three-dimensional excitation-emission matrix fluorescence spectroscopies and by dissolved organic carbon (DOC) content. The seasonal and <span class="hlt">air</span> <span class="hlt">mass</span> trajectory effects on dissolved organic matter (DOM) of bulk deposition were evaluated. The absorbance at 250 nm (UV(250 nm)) and integrated fluorescence showed to be positively correlated with each other, and they were also positively correlated to the DOC in bulk deposition, which suggest that a constant fraction of DOM is likely to fluoresce. There was more chromophoric dissolved organic matter (CDOM) present in summer and autumn seasons than in winter and spring. Bulk deposition associated with terrestrial <span class="hlt">air</span> <span class="hlt">masses</span> contained a higher CDOM content than bulk deposition related to marine <span class="hlt">air</span> <span class="hlt">masses</span>, thus highlighting the contribution of terrestrial/anthropogenic sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AtmEn..91..175H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AtmEn..91..175H"><span>New Directions: Questions surrounding suspended particle <span class="hlt">mass</span> used as a surrogate for <span class="hlt">air</span> quality and for regulatory control of ambient urban <span class="hlt">air</span> pollution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoare, John L.</p> <p>2014-07-01</p> <p>The original choice of particulate matter <span class="hlt">mass</span> (PM) as a realistic surrogate for gross <span class="hlt">air</span> pollution has gradually evolved into routine use nowadays of epidemiologically-based estimates of the monetary and other benefits expected from regulating urban <span class="hlt">air</span> quality. Unfortunately, the statistical associations facilitating such calculations usually are based on single indices of <span class="hlt">air</span> pollution whereas the health effects themselves are more broadly based causally. For this and other reasons the economic benefits of control tend to be exaggerated. Primarily because of their assumed inherently inferior respirability, particles ≥10 μm are generally excluded from such considerations. Where the particles themselves are chemically heterogeneous, as in an urban context, this may be inappropriate. Clearly all <span class="hlt">air</span>-borne particles, whether coarse or fine, are susceptible to inhalation. Hence, the possibility exists for any adhering potentially harmful semi-volatile substances to be subsequently de-sorbed in vivo thereby facilitating their transport deeper into the lungs. Consequently, this alone may be a sufficient reason for including rather than rejecting during <span class="hlt">air</span> quality monitoring the relatively coarse 10-100 μm particle fraction, ideally in conjunction with routine estimation of the gaseous co-pollutants thereby facilitating a multi-pollutant approach apropos regulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BoLMe.167..123G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BoLMe.167..123G"><span>Turbulence and <span class="hlt">Air</span> <span class="hlt">Exchange</span> in a Two-Dimensional Urban Street Canyon Between Gable Roof Buildings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garau, Michela; Badas, Maria Grazia; Ferrari, Simone; Seoni, Alessandro; Querzoli, Giorgio</p> <p>2018-04-01</p> <p>We experimentally investigate the effect of a typical building covering: the gable roof, on the flow and <span class="hlt">air</span> <span class="hlt">exchange</span> in urban canyons. In general, the morphology of the urban canopy is very varied and complex, depending on a large number of factors, such as building arrangement, or the morphology of the terrain. Therefore we focus on a simple, prototypal shape, the two-dimensional canyon, with the aim of elucidating some fundamental phenomena driving the street-canyon ventilation. Experiments are performed in a water channel, over an array of identical prismatic obstacles representing an idealized urban canopy. The aspect ratio, i.e. canyon-width to building-height ratio, ranges from 1 to 6. Gable roof buildings with 1:1 pitch are compared with flat roofed buildings. Velocity is measured using a particle-image-velocimetry technique with flow dynamics discussed in terms of mean flow and second- and third-order statistical moments of the velocity. The ventilation is interpreted by means of a simple well-mixed box model and the outflow rate and mean residence time are computed. Results show that gable roofs tend to delay the transition from the skimming-flow to the wake-interference regime and promote the development of a deeper and more turbulent roughness layer. The presence of a gable roof significantly increases the momentum flux, especially for high packing density. The <span class="hlt">air</span> <span class="hlt">exchange</span> is improved compared to the flat roof buildings, and the beneficial effect is more significant for narrow canyons. Accordingly, for unit aspect ratio gable roofs reduce the mean residence time by a factor of 0.37 compared to flat roofs, whereas the decrease is only by a factor of 0.9 at the largest aspect ratio. Data analysis indicates that, for flat roof buildings, the mean residence time increases by 30% when the aspect ratio is decreased from 6 to 2, whereas this parameter is only weakly dependent on aspect ratio in the case of gable roofs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JASMS.tmp..699H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JASMS.tmp..699H"><span>Conformational Assessment of Adnectin and Adnectin-Drug Conjugate by Hydrogen/Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Richard Y.-C.; O'Neil, Steven R.; Lipovšek, Daša; Chen, Guodong</p> <p>2018-05-01</p> <p>Higher-order structure (HOS) characterization of therapeutic protein-drug conjugates for comprehensive assessment of conjugation-induced protein conformational changes is an important consideration in the biopharmaceutical industry to ensure proper behavior of protein therapeutics. In this study, conformational dynamics of a small therapeutic protein, adnectin 1, together with its drug conjugate were characterized by hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) with different spatial resolutions. Top-down HDX allows detailed assessment of the residue-level deuterium content in the payload conjugation region. HDX-MS dataset revealed the ability of peptide-based payload/linker to retain deuterium in HDX experiments. Combined results from intact, top-down, and bottom-up HDX indicated no significant conformational changes of adnectin 1 upon payload conjugation. [Figure not available: see fulltext.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ACP....14.1205J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ACP....14.1205J"><span>On the relationship between Arctic ice clouds and polluted <span class="hlt">air</span> <span class="hlt">masses</span> over the North Slope of Alaska in April 2008</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jouan, C.; Pelon, J.; Girard, E.; Ancellet, G.; Blanchet, J. P.; Delanoë, J.</p> <p>2014-02-01</p> <p>Recently, two types of ice clouds (TICs) properties have been characterized using the Indirect and Semi-Direct Aerosol Campaign (ISDAC) airborne measurements (Alaska, April 2008). TIC-2B were characterized by fewer (< 10 L-1) and larger (> 110 μm) ice crystals, and a larger ice supersaturation (> 15%) compared to TIC-1/2A. It has been hypothesized that emissions of SO2 may reduce the ice nucleating properties of ice nuclei (IN) through acidification, resulting in a smaller concentration of larger ice crystals and leading to precipitation (e.g., cloud regime TIC-2B). Here, the origin of <span class="hlt">air</span> <span class="hlt">masses</span> forming the ISDAC TIC-1/2A (1 April 2008) and TIC-2B (15 April 2008) is investigated using trajectory tools and satellite data. Results show that the synoptic conditions favor <span class="hlt">air</span> <span class="hlt">masses</span> transport from three potential SO2 emission sources into Alaska: eastern China and Siberia where anthropogenic and biomass burning emissions, respectively, are produced, and the volcanic region of the Kamchatka/Aleutians. Weather conditions allow the accumulation of pollutants from eastern China and Siberia over Alaska, most probably with the contribution of acidic volcanic aerosol during the TIC-2B period. Observation Monitoring Instrument (OMI) satellite observations reveal that SO2 concentrations in <span class="hlt">air</span> <span class="hlt">masses</span> forming the TIC-2B were larger than in <span class="hlt">air</span> <span class="hlt">masses</span> forming the TIC-1/2A. Airborne measurements show high acidity near the TIC-2B flight where humidity was low. These results support the hypothesis that acidic coating on IN could be at the origin of the formation of TIC-2B.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050206364','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050206364"><span>High-Altitude <span class="hlt">Air</span> <span class="hlt">Mass</span> Zero Calibration of Solar Cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Woodyard, James R.; Snyder, David B.</p> <p>2005-01-01</p> <p><span class="hlt">Air</span> <span class="hlt">mass</span> zero calibration of solar cells has been carried out for several years by NASA Glenn Research Center using a Lear-25 aircraft and Langley plots. The calibration flights are carried out during early fall and late winter when the tropopause is at the lowest altitude. Measurements are made starting at about 50,000 feet and continue down to the tropopause. A joint NASA/Wayne State University program called Suntracker is underway to explore the use of weather balloon and communication technologies to characterize solar cells at elevations up to about 100 kft. The balloon flights are low-cost and can be carried out any time of the year. AMO solar cell characterization employing the mountaintop, aircraft and balloon methods are reviewed. Results of cell characterization with the Suntracker are reported and compared with the NASA Glenn Research Center aircraft method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982PhDT........65M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982PhDT........65M"><span>Dynamical <span class="hlt">Mass</span> Generation.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mendel Horwitz, Roberto Ruben</p> <p>1982-03-01</p> <p>In the framework of the Glashow-Weinberg-Salem model without elementary scalar particles, we show that <span class="hlt">masses</span> for fermions and intermediate vector bosons can be generated dynamically. The mechanism is the formation of fermion-antifermion pseudoscalar bound states of zero total four momentum, which form a condensate in the physical vacuum. The force responsible for the binding is the short distance part of the net Coulomb force due to photon and Z <span class="hlt">exchange</span>. Fermions and bosons acquire <span class="hlt">masses</span> through their interaction with this condensate. The neutrinos remain massless because their righthanded components have no interactions. Also the charge -1/3 quarks remain massless because the repulsive force from the Z <span class="hlt">exchange</span> dominates over the Coulomb force. To correct this, we propose two possible modifications to the theory. One is to cut off the Z <span class="hlt">exchange</span> at very small distances, so that all fermions except the neutrinos acquire <span class="hlt">masses</span>, which are then, purely electromagnetic in origin. The other is to introduce an additional gauge boson that couples to all quarks with a pure vector coupling. To make this vector boson unobservable at usual energies, at least two new fermions must couple to it. The vector boson squared <span class="hlt">masses</span> receive additive contributions from all the fermion squared <span class="hlt">masses</span>. The photon remains massless and the <span class="hlt">masses</span> of the Z and W('(+OR -)) bosons are shown to be related through the Weinberg angle in the conventional way. Assuming only three families of fermions, we obtain estimates for the top quark <span class="hlt">mass</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4288250','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4288250"><span>Investigating the Interaction between the Neonatal Fc Receptor and Monoclonal Antibody Variants by Hydrogen/Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry*</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jensen, Pernille Foged; Larraillet, Vincent; Schlothauer, Tilman; Kettenberger, Hubert; Hilger, Maximiliane; Rand, Kasper D.</p> <p>2015-01-01</p> <p>The recycling of immunoglobulins by the neonatal Fc receptor (FcRn) is of crucial importance in the maintenance of antibody levels in plasma and is responsible for the long half-lives of endogenous and recombinant monoclonal antibodies. From a therapeutic point of view there is great interest in understanding and modulating the IgG–FcRn interaction to optimize antibody pharmacokinetics and ultimately improve efficacy and safety. Here we studied the interaction between a full-length human IgG1 and human FcRn via hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry and targeted electron transfer dissociation to map sites perturbed by binding on both partners of the IgG–FcRn complex. Several regions in the antibody Fc region and the FcRn were protected from <span class="hlt">exchange</span> upon complex formation, in good agreement with previous crystallographic studies of FcRn in complex with the Fc fragment. Interestingly, we found that several regions in the IgG Fab region also showed reduced deuterium uptake. Our findings indicate the presence of hitherto unknown FcRn interaction sites in the Fab region or a possible conformational link between the IgG Fc and Fab regions upon FcRn binding. Further, we investigated the role of IgG glycosylation in the conformational response of the IgG–FcRn interaction. Removal of antibody glycans increased the flexibility of the FcRn binding site in the Fc region. Consequently, FcRn binding did not induce a similar conformational stabilization of deglycosylated IgG as observed for the wild-type glycosylated IgG. Our results provide new molecular insight into the IgG–FcRn interaction and illustrate the capability of hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry to advance structural proteomics by providing detailed information on the conformation and dynamics of large protein complexes in solution. PMID:25378534</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26ES...35a2003A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26ES...35a2003A"><span>The potential role of sea spray droplets in facilitating <span class="hlt">air</span>-sea gas transfer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andreas, E. L.; Vlahos, P.; Monahan, E. C.</p> <p>2016-05-01</p> <p>For over 30 years, <span class="hlt">air</span>-sea interaction specialists have been evaluating and parameterizing the role of whitecap bubbles in <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span>. To our knowledge, no one, however, has studied the mirror image process of whether sea spray droplets can facilitate <span class="hlt">air</span>-sea gas <span class="hlt">exchange</span>. We are therefore using theory, data analysis, and numerical modeling to quantify the role of spray on <span class="hlt">air</span>-sea gas transfer. In this, our first formal work on this subject, we seek the rate-limiting step in spray-mediated gas transfer by evaluating the three time scales that govern the <span class="hlt">exchange</span>: τ <span class="hlt">air</span> , which quantifies the rate of transfer between the atmospheric gas reservoir and the surface of the droplet; τ int , which quantifies the <span class="hlt">exchange</span> rate across the <span class="hlt">air</span>-droplet interface; and τ aq , which quantifies gas mixing within the aqueous solution droplet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19476883','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19476883"><span><span class="hlt">Mass</span> casualty tracking with <span class="hlt">air</span> traffic control methodologies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hoskins, Jason D; Graham, Ross F; Robinson, Duane R; Lutz, Clifford C; Folio, Les R</p> <p>2009-06-01</p> <p>An intrahospital casualty throughput system modeled after <span class="hlt">air</span> traffic control (ATC) tracking procedures was tested in <span class="hlt">mass</span> casualty exercises. ATC uses a simple tactile process involving informational progress strips representing each aircraft, which are held in bays representing each stage of flight to prioritize and manage aircraft. These strips can be reordered within the bays to indicate a change in priority of aircraft sequence. In this study, a similar system was designed for patient tracking. We compared the ATC model and traditional casualty tracking methods of paper and clipboard in 18 four-hour casualty scenarios, each with 5 to 30 mock casualties. The experimental and control groups were alternated to maximize exposure and minimize training effects. Results were analyzed with Mann-Whitney statistical analysis with p value < 0.05 (two-sided). The ATC method had significantly (p = 0.017) fewer errors in critical patient data (eg, name, social security number, diagnosis). Specifically, the ATC method better tracked the mechanism of injury, working diagnosis, and disposition of patients. The ATC method also performed considerably better with patient accountability during <span class="hlt">mass</span> casualty scenarios. Data strips were comparable with the control method in terms of ease of use. In addition, participants preferred the ATC method to the control (p = 0.003) and preferred using the ATC method (p = 0.003) to traditional methods in the future. The ATC model more effectively tracked patient data with fewer errors when compared with the clipboard method. Application of these principles can enhance trauma management and can have application in civilian and military trauma centers and emergency rooms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4465451','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4465451"><span>Imidazole C-2 Hydrogen/Deuterium <span class="hlt">Exchange</span> Reaction at Histidine for Probing Protein Structure and Function with MALDI <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hayashi, Naoka; Kuyama, Hiroki; Nakajima, Chihiro; Kawahara, Kazuki; Miyagi, Masaru; Nishimura, Osamu; Matsuo, Hisayuki; Nakazawa, Takashi</p> <p>2015-01-01</p> <p>We present a <span class="hlt">mass</span> spectrometric method for analyzing protein structure and function, based on the imidazole C-2 or histidine Cε1 hydrogen/deuterium (H/D) <span class="hlt">exchange</span> reaction, which is intrinsically second order with respect to the concentrations of the imidazolium cation and OD− in D2O. The second-order rate constant (k2) of this reaction was calculated from the pH-dependency of the pseudo-first-order rate constant (kφ) obtained from the change of average <span class="hlt">mass</span> ΔMr (0 ≤ ΔMr < 1) of a peptide fragment containing a defined histidine residue at incubation time (t) such that kφ = − [ln(1−ΔMr)]/t. We preferred using k2 rather than kφ because k2max (maximal value of k2) was empirically related to pKa as illustrated with a Brønsted plot: logk2max=-0.7pKa+α (α is an arbitrary constant), so that we could analyze the effect of structure on the H/D-<span class="hlt">exchange</span> rate in terms of log(k2max/k2) representing the deviation of k2 from k2max. In the catalytic site of bovine ribonuclease A, His12 showed much larger change in log(k2max/k2) compared with His119 upon binding with cytidine 3′-monophosphate, as anticipated from the X-ray structures and the possible change in solvent accessibility. However, there is a need of considering the hydrogen bonds of the imidazole group with non-dissociable groups to interpret an extremely slow H/D <span class="hlt">exchange</span> rate of His48 in partially solvent-exposed situation. PMID:24606199</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4992071','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4992071"><span>Features of <span class="hlt">air</span> <span class="hlt">masses</span> associated with the deposition of Pseudomonas syringae and Botrytis cinerea by rain and snowfall</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Monteil, Caroline L; Bardin, Marc; Morris, Cindy E</p> <p>2014-01-01</p> <p>Clarifying the role of precipitation in microbial dissemination is essential for elucidating the processes involved in disease emergence and spread. The ecology of Pseudomonas syringae and its presence throughout the water cycle makes it an excellent model to address this issue. In this study, 90 samples of freshly fallen rain and snow collected from 2005–2011 in France were analyzed for microbiological composition. The conditions favorable for dissemination of P. syringae by this precipitation were investigated by (i) estimating the physical properties and backward trajectories of the <span class="hlt">air</span> <span class="hlt">masses</span> associated with each precipitation event and by (ii) characterizing precipitation chemistry, and genetic and phenotypic structures of populations. A parallel study with the fungus Botrytis cinerea was also performed for comparison. Results showed that (i) the relationship of P. syringae to precipitation as a dissemination vector is not the same for snowfall and rainfall, whereas it is the same for B. cinerea and (ii) the occurrence of P. syringae in precipitation can be linked to electrical conductivity and pH of water, the trajectory of the <span class="hlt">air</span> <span class="hlt">mass</span> associated with the precipitation and certain physical conditions of the <span class="hlt">air</span> <span class="hlt">mass</span> (i.e. temperature, solar radiation exposure, distance traveled), whereas these predictions are different for B. cinerea. These results are pertinent to understanding microbial survival, emission sources and atmospheric processes and how they influence microbial dissemination. PMID:24722630</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24722630','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24722630"><span>Features of <span class="hlt">air</span> <span class="hlt">masses</span> associated with the deposition of Pseudomonas syringae and Botrytis cinerea by rain and snowfall.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Monteil, Caroline L; Bardin, Marc; Morris, Cindy E</p> <p>2014-11-01</p> <p>Clarifying the role of precipitation in microbial dissemination is essential for elucidating the processes involved in disease emergence and spread. The ecology of Pseudomonas syringae and its presence throughout the water cycle makes it an excellent model to address this issue. In this study, 90 samples of freshly fallen rain and snow collected from 2005-2011 in France were analyzed for microbiological composition. The conditions favorable for dissemination of P. syringae by this precipitation were investigated by (i) estimating the physical properties and backward trajectories of the <span class="hlt">air</span> <span class="hlt">masses</span> associated with each precipitation event and by (ii) characterizing precipitation chemistry, and genetic and phenotypic structures of populations. A parallel study with the fungus Botrytis cinerea was also performed for comparison. Results showed that (i) the relationship of P. syringae to precipitation as a dissemination vector is not the same for snowfall and rainfall, whereas it is the same for B. cinerea and (ii) the occurrence of P. syringae in precipitation can be linked to electrical conductivity and pH of water, the trajectory of the <span class="hlt">air</span> <span class="hlt">mass</span> associated with the precipitation and certain physical conditions of the <span class="hlt">air</span> <span class="hlt">mass</span> (i.e. temperature, solar radiation exposure, distance traveled), whereas these predictions are different for B. cinerea. These results are pertinent to understanding microbial survival, emission sources and atmospheric processes and how they influence microbial dissemination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3348023','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3348023"><span>An anthropometric model to estimate neonatal fat <span class="hlt">mass</span> using <span class="hlt">air</span> displacement plethysmography</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Background Current validated neonatal body composition methods are limited/impractical for use outside of a clinical setting because they are labor intensive, time consuming, and require expensive equipment. The purpose of this study was to develop an anthropometric model to estimate neonatal fat <span class="hlt">mass</span> (kg) using an <span class="hlt">air</span> displacement plethysmography (PEA POD® Infant Body Composition System) as the criterion. Methods A total of 128 healthy term infants, 60 females and 68 males, from a multiethnic cohort were included in the analyses. Gender, race/ethnicity, gestational age, age (in days), anthropometric measurements of weight, length, abdominal circumference, skin-fold thicknesses (triceps, biceps, sub scapular, and thigh), and body composition by PEA POD® were collected within 1-3 days of birth. Backward stepwise linear regression was used to determine the model that best predicted neonatal fat <span class="hlt">mass</span>. Results The statistical model that best predicted neonatal fat <span class="hlt">mass</span> (kg) was: -0.012 -0.064*gender + 0.024*day of measurement post-delivery -0.150*weight (kg) + 0.055*weight (kg)2 + 0.046*ethnicity + 0.020*sum of three skin-fold thicknesses (triceps, sub scapular, and thigh); R2 = 0.81, MSE = 0.08 kg. Conclusions Our anthropometric model explained 81% of the variance in neonatal fat <span class="hlt">mass</span>. Future studies with a greater variety of neonatal anthropometric measurements may provide equations that explain more of the variance. PMID:22436534</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RScI...83f3503B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RScI...83f3503B"><span>Surface analysis using a new plasma assisted desorption/ionisation source for <span class="hlt">mass</span> spectrometry in ambient <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bowfield, A.; Barrett, D. A.; Alexander, M. R.; Ortori, C. A.; Rutten, F. M.; Salter, T. L.; Gilmore, I. S.; Bradley, J. W.</p> <p>2012-06-01</p> <p>The authors report on a modified micro-plasma assisted desorption/ionisation (PADI) device which creates plasma through the breakdown of ambient <span class="hlt">air</span> rather than utilising an independent noble gas flow. This new micro-PADI device is used as an ion source for ambient <span class="hlt">mass</span> spectrometry to analyse species released from the surfaces of polytetrafluoroethylene, and generic ibuprofen and paracetamol tablets through remote activation of the surface by the plasma. The <span class="hlt">mass</span> spectra from these surfaces compare favourably to those produced by a PADI device constructed using an earlier design and confirm that the new ion source is an effective device which can be used to achieve ambient <span class="hlt">mass</span> spectrometry with improved spatial resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23192280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23192280"><span>Measurement of the <span class="hlt">mass</span> energy-absorption coefficient of <span class="hlt">air</span> for x-rays in the range from 3 to 60 keV.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Buhr, H; Büermann, L; Gerlach, M; Krumrey, M; Rabus, H</p> <p>2012-12-21</p> <p>For the first time the absolute photon <span class="hlt">mass</span> energy-absorption coefficient of <span class="hlt">air</span> in the energy range of 10 to 60 keV has been measured with relative standard uncertainties below 1%, considerably smaller than those of up to 2% assumed for calculated data. For monochromatized synchrotron radiation from the electron storage ring BESSY II both the radiant power and the fraction of power deposited in dry <span class="hlt">air</span> were measured using a cryogenic electrical substitution radiometer and a free <span class="hlt">air</span> ionization chamber, respectively. The measured absorption coefficients were compared with state-of-the art calculations and showed an average deviation of 2% from calculations by Seltzer. However, they agree within 1% with data calculated earlier by Hubbell. In the course of this work, an improvement of the data analysis of a previous experimental determination of the <span class="hlt">mass</span> energy-absorption coefficient of <span class="hlt">air</span> in the range of 3 to 10 keV was found to be possible and corrected values of this preceding study are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ThEng..63..329M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ThEng..63..329M"><span>Startup of <span class="hlt">air</span>-cooled condensers and dry cooling towers at low temperatures of the cooling <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Milman, O. O.; Ptakhin, A. V.; Kondratev, A. V.; Shifrin, B. A.; Yankov, G. G.</p> <p>2016-05-01</p> <p>The problems of startup and performance of <span class="hlt">air</span>-cooled condensers (ACC) and dry cooling towers (DCT) at low cooling <span class="hlt">air</span> temperatures are considered. Effects of the startup of the ACC at sub-zero temperatures are described. Different options of the ACC heating up are analyzed, and examples of existing technologies are presented (electric heating, heating up with hot <span class="hlt">air</span> or steam, and internal and external heating). The use of additional heat <span class="hlt">exchanging</span> sections, steam tracers, in the DCT design is described. The need for high power in cases of electric heating and heating up with hot <span class="hlt">air</span> is noted. An experimental stand for research and testing of the ACC startup at low temperatures is described. The design of the three-pass ACC unit is given, and its advantages over classical single-pass design at low temperatures are listed. The formation of ice plugs inside the heat <span class="hlt">exchanging</span> tubes during the start-up of ACC and DCT at low cooling <span class="hlt">air</span> temperatures is analyzed. Experimental data on the effect of the steam flow rate, steam nozzle distance from the heat-<span class="hlt">exchange</span> surface, and their orientation in space on the metal temperature were collected, and test results are analyzed. It is noted that the surface temperature at the end of the heat up is almost independent from its initial temperature. Recommendations for the safe start-up of ACCs and DCTs are given. The heating flow necessary to sufficiently heat up heat-<span class="hlt">exchange</span> surfaces of ACCs and DCTs for the safe startup is estimated. The technology and the process of the heat up of the ACC with the heating steam external supply are described by the example of the startup of the full-scale section of the ACC at sub-zero temperatures of the cooling <span class="hlt">air</span>, and the advantages of the proposed start-up technology are confirmed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ACPD...1313285B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ACPD...1313285B"><span><span class="hlt">Air</span>/sea DMS gas transfer in the North Atlantic: evidence for limited interfacial gas <span class="hlt">exchange</span> at high wind speed</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bell, T. G.; De Bruyn, W.; Miller, S. D.; Ward, B.; Christensen, K.; Saltzman, E. S.</p> <p>2013-05-01</p> <p>Shipboard measurements of eddy covariance DMS <span class="hlt">air</span>/sea fluxes and seawater concentration were carried out in the North Atlantic bloom region in June/July 2011. Gas transfer coefficients (k660) show a linear dependence on mean horizontal wind speed at wind speeds up to 11 m s-1. At higher wind speeds the relationship between k660 and wind speed weakens. At high winds, measured DMS fluxes were lower than predicted based on the linear relationship between wind speed and interfacial stress extrapolated from low to intermediate wind speeds. In contrast, the transfer coefficient for sensible heat did not exhibit this effect. The apparent suppression of <span class="hlt">air</span>/sea gas flux at higher wind speeds appears to be related to sea state, as determined from shipboard wave measurements. These observations are consistent with the idea that long waves suppress near surface water side turbulence, and decrease interfacial gas transfer. This effect may be more easily observed for DMS than for less soluble gases, such as CO2, because the <span class="hlt">air</span>/sea <span class="hlt">exchange</span> of DMS is controlled by interfacial rather than bubble-mediated gas transfer under high wind speed conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993ONERA..75.....A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993ONERA..75.....A"><span>High temperature heat <span class="hlt">exchangers</span> for gas turbines and future hypersonic <span class="hlt">air</span> breathing propulsion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Avran, Patrick; Bernard, Pierre</p> <p></p> <p>After surveying the results of ONERA's investigations to date of metallic and ceramic heat <span class="hlt">exchangers</span> applicable to automotive and aircraft powerplants, which are primarily of finned-tube counterflow configuration, attention is given to the influence of heat-<span class="hlt">exchanger</span> effectiveness on fuel consumption and <span class="hlt">exchanger</span> dimensions and weight. Emphasis is placed on the results of studies of cryogenic heat <span class="hlt">exchangers</span> used by airbreathing hypersonic propulsion systems. The numerical codes developed by ONERA for the modeling of heat <span class="hlt">exchanger</span> thermodynamics are evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ACPD...13.4331J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ACPD...13.4331J"><span>On the relationship between Arctic ice clouds and polluted <span class="hlt">air</span> <span class="hlt">masses</span> over the north slope of Alaska in April 2008</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jouan, C.; Pelon, J.; Girard, E.; Ancellet, G.; Blanchet, J. P.; Delanoë, J.</p> <p>2013-02-01</p> <p>Recently, two Types of Ice Clouds (TICs) properties have been characterized using ISDAC airborne measurements (Alaska, April 2008). TIC-2B were characterized by fewer (<10 L-1) and larger (>110 μm) ice crystals, a larger ice supersaturation (>15%) and a fewer ice nuclei (IN) concentration (<2 order of magnitude) when compared to TIC-1/2A. It has been hypothesized that emissions of SO2 may reduce the ice nucleating properties of IN through acidification, resulting to a smaller concentration of larger ice crystals and leading to precipitation (e.g. cloud regime TIC-2B) because of the reduced competition for the same available moisture. Here, the origin of <span class="hlt">air</span> <span class="hlt">masses</span> forming the ISDAC TIC-1/2A (1 April 2008) and TIC-2B (15 April 2008) is investigated using trajectory tools and satellite data. Results show that the synoptic conditions favor <span class="hlt">air</span> <span class="hlt">masses</span> transport from the three potentials SO2 emission areas to Alaska: eastern China and Siberia where anthropogenic and biomass burning emission respectively are produced and the volcanic region from the Kamchatka/Aleutians. Weather conditions allow the accumulation of pollutants from eastern China/Siberia over Alaska, most probably with the contribution of acid volcanic aerosol during the TIC-2B period. OMI observations reveal that SO2 concentrations in <span class="hlt">air</span> <span class="hlt">masses</span> forming the TIC-2B were larger than in <span class="hlt">air</span> <span class="hlt">masses</span> forming the TIC-1/2A. Airborne measurements show high acidity near the TIC-2B flight where humidity was low. These results strongly support the hypothesis that acidic coating on IN are at the origin of the formation of TIC-2B.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=546779','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=546779"><span>Gas <span class="hlt">Exchange</span> of Algae</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ammann, Elizabeth C. B.; Lynch, Victoria H.</p> <p>1966-01-01</p> <p>Changes in the oxygen partial pressure of <span class="hlt">air</span> over the range of 8 to 258 mm of Hg did not adversely affect the photosynthetic capacity of Chlorella pyrenoidosa. Gas <span class="hlt">exchange</span> and growth measurements remained constant for 3-week periods and were similar to <span class="hlt">air</span> controls (oxygen pressure of 160 mm of Hg). Oxygen partial pressures of 532 and 745 mm of Hg had an adverse effect on algal metabolism. Carbon dioxide consumption was 24% lower in the gas mixture containing oxygen at a pressure 532 mm of Hg than in the <span class="hlt">air</span> control, and the growth rate was slightly reduced. Oxygen at a partial pressure of 745 mm of Hg decreased the photosynthetic rate 39% and the growth rate 37% over the corresponding rates in <span class="hlt">air</span>. The lowered metabolic rates remained constant during 14 days of measurements, and the effect was reversible after this time. Substitution of helium or argon for the nitrogen in <span class="hlt">air</span> had no effect on oxygen production, carbon dioxide consumption, or growth rate for 3-week periods. All measurements were made at a total pressure of 760 mm of Hg, and all gas mixtures were enriched with 2% carbon dioxide. Thus, the physiological functioning and reliability of a photosynthetic gas <span class="hlt">exchanger</span> should not be adversely affected by: (i) oxygen partial pressures ranging from 8 to 258 mm of Hg; (ii) the use of pure oxygen at reduced total pressure (155 to 258 mm of Hg) unless pressure per se affects photosynthesis, or (iii) the inclusion of helium or argon in the gas environment (up to a partial pressure of 595 mm of Hg). PMID:5927028</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15298198','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15298198"><span><span class="hlt">Exchange</span> of polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) between <span class="hlt">air</span> and a mixed pasture sward.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barber, Jonathan L; Thomas, Gareth O; Bailey, Rebekah; Kerstiens, Gerhard; Jones, Kevin C</p> <p>2004-07-15</p> <p> pasture-to-<span class="hlt">air</span> <span class="hlt">exchange</span> of gas-phase PCBs and PCNs; i.e., differences between plant species in cuticle composition and/or structure affecting the permeability of the cuticle are of greater importance than differences in leaf morphology affecting aerodynamic roughness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18522097','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18522097"><span>Measurement and modeling of diel variability of polybrominated diphenyl ethers and chlordanes in <span class="hlt">air</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moeckel, Claudia; Macleod, Matthew; Hungerbühler, Konrad; Jones, Kevin C</p> <p>2008-05-01</p> <p>Short-term variability of concentrations of polybrominated diphenyl ethers (PBDEs) and chlordanes in <span class="hlt">air</span> at a semirural site in England over a 5 day period is reported. Four-hour <span class="hlt">air</span> samples were collected during a period dominated by a high pressure system that produced stable diel (24-h) patterns of meteorological conditions such as temperature and atmospheric boundary layer height. PBDE and chlordane concentrations showed clear diel variability with concentrations in the afternoon and evening being 1.9 - 2.7 times higher than in the early morning. The measurements are interpreted using a multimedia <span class="hlt">mass</span> balance model parametrized with forcing functions representing local temperature, atmospheric boundary layer height, wind speed and hydroxyl radical concentrations. Model results indicate that reversible, temperature-controlled <span class="hlt">air</span>-surface <span class="hlt">exchange</span> is the primary driver of the diel concentration pattern observed for chlordanes and PBDE 28. For higher brominated PBDE congeners (47, 99 and 100), the effect of variable atmospheric mixing height in combination with irreversible deposition on aerosol particles is dominant and explains the diel patterns almost entirely. Higher concentrations of chlordanes and PBDEs in <span class="hlt">air</span> observed at the end of the study period could be related to likely source areas using back trajectory analysis. This is the first study to clearly document diel variability in concentrations of PBDEs in <span class="hlt">air</span> over a period of several days. Our model analysis indicates that high daytime and low nighttime concentrations of semivolatile organic chemicals can arise from different underlying driving processes, and are not necessarily evidence of reversible <span class="hlt">air</span>-surface <span class="hlt">exchange</span> on a 24-h time scale.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26910987','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26910987"><span>[Summer Greenhouse Gases <span class="hlt">Exchange</span> Flux Across Water-<span class="hlt">air</span> Interface in Three Water Reservoirs Located in Different Geologic Setting in Guangxi, China].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Jian-hong; Pu, Jun-bing; Sun, Ping-an; Yuan, Dao-xian; Liu, Wen; Zhang, Tao; Mo, Xue</p> <p>2015-11-01</p> <p>Due to special hydrogeochemical characteristics of calcium-rich, alkaline and DIC-rich ( dissolved inorganic carbon) environment controlled by the weathering products from carbonate rock, the <span class="hlt">exchange</span> characteristics, processes and controlling factors of greenhouse gas (CO2 and CH4) across water-<span class="hlt">air</span> interface in karst water reservoir show obvious differences from those of non-karst water reservoir. Three water reservoirs (Dalongdong reservoir-karst reservoir, Wulixia reservoir--semi karst reservoir, Si'anjiang reservoir-non-karst reservoir) located in different geologic setting in Guangxi Zhuang Autonomous Region, China were chosen to reveal characteristics and controlling factors of greenhouse gas <span class="hlt">exchange</span> flux across water-<span class="hlt">air</span> interface. Two common approaches, floating chamber (FC) and thin boundary layer models (TBL), were employed to research and contrast greenhouse gas <span class="hlt">exchange</span> flux across water-<span class="hlt">air</span> interface from three reservoirs. The results showed that: (1) surface-layer water in reservoir area and discharging water under dam in Dalongdong water reservoir were the source of atmospheric CO2 and CH4. Surface-layer water in reservoir area in Wulixia water reservoir was the sink of atmospheric CO2 and the source of atmospheric CH4, while discharging water under dam was the source of atmospheric CO2 and CH4. Surface-layer water in Si'anjiang water reservoir was the sink of atmospheric CO2 and source of atmospheric CH4. (2) CO2 and CH4 effluxes in discharging water under dam were much more than those in surface-layer water in reservoir area regardless of karst reservoir or non karst reservoir. Accordingly, more attention should be paid to the CO2 and CH4 emission from discharging water under dam. (3) In the absence of submerged soil organic matters and plants, the difference of CH4 effluxes between karst groundwater-fed reservoir ( Dalongdong water reservoir) and non-karst area ( Wulixia water reservoir and Si'anjiang water reservoir) was less. However, CO2</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15213705','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15213705"><span>Relationship of Indoor, Outdoor and Personal <span class="hlt">Air</span> (RIOPA) study: study design, methods and quality assurance/control results.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Weisel, Clifford P; Zhang, Junfeng; Turpin, Barbara J; Morandi, Maria T; Colome, Steven; Stock, Thomas H; Spektor, Dalia M; Korn, Leo; Winer, Arthur; Alimokhtari, Shahnaz; Kwon, Jaymin; Mohan, Krishnan; Harrington, Robert; Giovanetti, Robert; Cui, William; Afshar, Masoud; Maberti, Silvia; Shendell, Derek</p> <p>2005-03-01</p> <p>The Relationship of Indoor, Outdoor and Personal <span class="hlt">Air</span> (RIOPA) Study was undertaken to evaluate the contribution of outdoor sources of <span class="hlt">air</span> toxics, as defined in the 1990 Clean <span class="hlt">Air</span> Act Amendments, to indoor concentrations and personal exposures. The concentrations of 18 volatile organic compounds (VOCs), 17 carbonyl compounds, and fine particulate matter <span class="hlt">mass</span> (PM(2.5)) were measured using 48-h outdoor, indoor and personal <span class="hlt">air</span> samples collected simultaneously. PM2.5 <span class="hlt">mass</span>, as well as several component species (elemental carbon, organic carbon, polyaromatic hydrocarbons and elemental analysis) were also measured; only PM(2.5) <span class="hlt">mass</span> is reported here. Questionnaires were administered to characterize homes, neighborhoods and personal activities that might affect exposures. The <span class="hlt">air</span> <span class="hlt">exchange</span> rate was also measured in each home. Homes in close proximity (<0.5 km) to sources of <span class="hlt">air</span> toxics were preferentially (2:1) selected for sampling. Approximately 100 non-smoking households in each of Elizabeth, NJ, Houston, TX, and Los Angeles, CA were sampled (100, 105, and 105 respectively) with second visits performed at 84, 93, and 81 homes in each city, respectively. VOC samples were collected at all homes, carbonyls at 90% and PM(2.5) at 60% of the homes. Personal samples were collected from nonsmoking adults and a portion of children living in the target homes. This manuscript provides the RIOPA study design and quality control and assurance data. The results from the RIOPA study can potentially provide information on the influence of ambient sources on indoor <span class="hlt">air</span> concentrations and exposure for many <span class="hlt">air</span> toxics and will furnish an opportunity to evaluate exposure models for these compounds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Cryo...80...97Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Cryo...80...97Y"><span>Numerical study of heat transfer characteristics in BOG heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan, Yan; Pfotenhauer, John M.; Miller, Franklin; Ni, Zhonghua; Zhi, Xiaoqin</p> <p>2016-12-01</p> <p>In this study, a numerical study of turbulent flow and the heat transfer process in a boil-off liquefied natural gas (BOG) heat <span class="hlt">exchanger</span> was performed. Finite volume computational fluid dynamics and the k - ω based shear stress transport model were applied to simulate thermal flow of BOG and ethylene glycol in a full-sized 3D tubular heat <span class="hlt">exchanger</span>. The simulation model has been validated and compared with the engineering specification data from its supplier. In order to investigate thermal characteristics of the heat <span class="hlt">exchanger</span>, velocity, temperature, heat flux and thermal response were studied under different <span class="hlt">mass</span> flowrates in the shell-side. The shell-side flow pattern is mostly determined by viscous forces, which lead to a small velocity and low temperature buffer area in the bottom-right corner of the heat <span class="hlt">exchanger</span>. Changing the shell-side <span class="hlt">mass</span> flowrate could result in different distributions of the shell-side flow. However, the distribution in the BOG will remain in a relatively stable pattern. Heat flux increases along with the shell-side <span class="hlt">mass</span> flowrate, but the increase is not linear. The ratio of increased heat flux to the <span class="hlt">mass</span> flow interval is superior at lower <span class="hlt">mass</span> flow conditions, and the threshold <span class="hlt">mass</span> flow for stable working conditions is defined as greater than 0.41 kg/s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991mshe.reptS....D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991mshe.reptS....D"><span>Microtube strip heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doty, F. D.</p> <p>1991-10-01</p> <p>This progress report is for the September-October 1991 quarter. We have demonstrated feasibility of higher specific conductance by a factor of five than any other work in high-temperature gas-to-gas <span class="hlt">exchangers</span>. These laminar-flow, microtube <span class="hlt">exchangers</span> exhibit extremely low pressure drop compared to alternative compact designs under similar conditions because of their much shorter flow length and larger total flow area for lower flow velocities. The design appears to be amenable to <span class="hlt">mass</span> production techniques, but considerable process development remains. The reduction in materials usage and the improved heat <span class="hlt">exchanger</span> performance promise to be of enormous significance in advanced engine designs and in cryogenics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1175556','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1175556"><span>Co-flow anode/cathode supply heat <span class="hlt">exchanger</span> for a solid-oxide fuel cell assembly</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Haltiner, Jr., Karl J.; Kelly, Sean M.</p> <p>2005-11-22</p> <p>In a solid-oxide fuel cell assembly, a co-flow heat <span class="hlt">exchanger</span> is provided in the flow paths of the reformate gas and the cathode <span class="hlt">air</span> ahead of the fuel cell stack, the reformate gas being on one side of the <span class="hlt">exchanger</span> and the cathode <span class="hlt">air</span> being on the other. The reformate gas is at a substantially higher temperature than is desired in the stack, and the cathode gas is substantially cooler than desired. In the co-flow heat <span class="hlt">exchanger</span>, the temperatures of the reformate and cathode streams converge to nearly the same temperature at the outlet of the <span class="hlt">exchanger</span>. Preferably, the heat <span class="hlt">exchanger</span> is formed within an integrated component manifold (ICM) for a solid-oxide fuel cell assembly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25706557','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25706557"><span>Indoor <span class="hlt">air</span> condensate as a novel matrix for monitoring inhalable organic contaminants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roll, Isaac B; Halden, Rolf U; Pycke, Benny F G</p> <p>2015-05-15</p> <p>With the population of developed nations spending nearly 90% of their time indoors, indoor <span class="hlt">air</span> quality (IAQ) is a critical indicator of human health risks from inhalation of airborne contaminants. We present a novel approach for qualitative monitoring of IAQ through the collection and analysis of indoor <span class="hlt">air</span> condensate discharged from heat <span class="hlt">exchangers</span> of heating, ventilation, and <span class="hlt">air</span> conditioning (HVAC) systems. Condensate samples were collected from six suburban homes and one business in Maricopa County, Arizona, concentrated via solid-phase extraction, analyzed for 10 endocrine disrupting chemicals (EDCs) by liquid chromatography-tandem <span class="hlt">mass</span> spectrometry (LC-MS/MS), and screened for additional organic compounds by gas chromatography-<span class="hlt">mass</span> spectrometry (GC-MS). All 10 EDCs were detected in at least one of the sampled buildings. More than 100 additional compounds were detected by GC-MS, of which 40 were tentatively identified using spectral database searches. Twelve compounds listed as designated chemicals for biomonitoring by the California Environmental Contaminant Biomonitoring Program were detected. Microfiltration of condensate samples prior to extraction had no discernable effect on contaminant concentration, suggesting that contaminants were freely dissolved or associated with inhalable, submicron particles. This study is the first to document the utility of HVAC condensate for the qualitative assessment of indoor <span class="hlt">air</span> for pollutants. Copyright © 2015 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Metro..50..532C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Metro..50..532C"><span>Stability of reference <span class="hlt">masses</span>: VII. Cleaning methods in <span class="hlt">air</span> and vacuum applied to a platinum <span class="hlt">mass</span> standard similar to the international and national kilogram prototypes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cumpson, Peter J.; Sano, Naoko; Barlow, Anders J.; Portoles, Jose F.</p> <p>2013-10-01</p> <p>Mercury contamination and the build-up of carbonaceous contamination are two contributing factors to the instability observed in kilogram prototype <span class="hlt">masses</span>. The kilogram prototypes that lie at the core of the dissemination of the SI base unit were manufactured in the late 19th century, and have polished surfaces. In papers IV and V of this series we developed a method for cleaning noble metal <span class="hlt">mass</span> standards in <span class="hlt">air</span> to remove carbonaceous contamination. At the core of this ‘UVOPS’ protocol is the application of UV light and ozone gas generated in situ in <span class="hlt">air</span>. The precise nature of the carbonaceous contamination that builds up on such surfaces is difficult to mimic demonstrably or quickly on new test surfaces, yet data from such tests are needed to provide the final confidence to allow UVOPS to be applied to a real 19th century kilogram prototype. Therefore, in the present work we have applied the UVOPS method to clean a platinum avoirdupois pound <span class="hlt">mass</span> standard, ‘RS2’, manufactured in the mid-19th century. This is thought to have been polished in a similar manner to the kilogram prototypes. To our knowledge this platinum surface has not previously been cleaned by any method. We used x-ray photoelectron spectroscopy to identify organic contamination, and weighing to quantify the <span class="hlt">mass</span> lost at each application of the UVOPS procedure. The UVOPS procedure is shown to be very effective. It is likely that the redefinition of the kilogram will require <span class="hlt">mass</span> comparisons in vacuum in the years to come. Therefore, in addition to UVOPS a cleaning method for use in vacuum will also be needed. We introduce and evaluate gas cluster ion-beam (GCIB) treatment as a potential method for cleaning reference <span class="hlt">masses</span> in vacuum. Again, application of this GCIB cleaning to a real artefact, RS2, allows us to make a realistic evaluation of its performance. While it has some attractive features, we cannot recommend it for cleaning <span class="hlt">mass</span> standards in its present form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020039007&hterms=syed&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DN%2Bsyed','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020039007&hterms=syed&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DN%2Bsyed"><span>Large-Scale <span class="hlt">Air</span> <span class="hlt">Mass</span> Characteristics Observed Over the Remote Tropical Pacific Ocean During March-April 1999: Results from PEM-Tropics B Field Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Browell, Edward V.; Fenn, Marta A.; Butler, Carolyn F.; Grant, William B.; Ismail, Syed; Ferrare, Richard A.; Kooi, Susan A.; Brackett, Vincent G.; Clayton, Marian B.; Avery, Melody A.</p> <p>2001-01-01</p> <p>Eighteen long-range flights over the Pacific Ocean between 38 S to 20 N and 166 E to 90 W were made by the NASA DC-8 aircraft during the NASA Pacific Exploratory Mission (PEM) Tropics B conducted from March 6 to April 18, 1999. Two lidar systems were flown on the DC-8 to remotely measure vertical profiles of ozone (O3), water vapor (H2O), aerosols, and clouds from near the surface to the upper troposphere along their flight track. In situ measurements of a wide range of gases and aerosols were made on the DC-8 for comprehensive characterization of the <span class="hlt">air</span> and for correlation with the lidar remote measurements. The transition from northeasterly flow of Northern Hemispheric (NH) <span class="hlt">air</span> on the northern side of the Intertropical Convergence Zone (ITCZ) to generally easterly flow of Southern Hemispheric (SH) <span class="hlt">air</span> south of the ITCZ was accompanied by a significant decrease in O3, carbon monoxide, hydrocarbons, and aerosols and an increase in H2O. Trajectory analyses indicate that <span class="hlt">air</span> north of the ITCZ came from Asia and/or the United States, while the <span class="hlt">air</span> south of the ITCZ had a long residence time over the Pacific, perhaps originating over South America several weeks earlier. <span class="hlt">Air</span> south of the South Pacific Convergence Zone (SPCZ) came rapidly from the west originating over Australia or Africa. This <span class="hlt">air</span> had enhanced O3 and aerosols and an associated decrease in H2O. Average latitudinal and longitudinal distributions of O3 and H2O were constructed from the remote and in situ O3 and H2O data, and these distributions are compared with results from PEM-Tropics A conducted in August-October 1996. During PEM-Tropics B, low O3 <span class="hlt">air</span> was found in the SH across the entire Pacific Basin at low latitudes. This was in strong contrast to the photochemically enhanced O3 levels found across the central and eastern Pacific low latitudes during PEM-Tropics A. Nine <span class="hlt">air</span> <span class="hlt">mass</span> types were identified for PEM-Tropics B based on their O3, aerosols, clouds, and potential vorticity characteristics. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15782902','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15782902"><span>Quantification of the heat <span class="hlt">exchange</span> of chicken eggs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Brecht, A; Hens, H; Lemaire, J L; Aerts, J M; Degraeve, P; Berckmans, D</p> <p>2005-03-01</p> <p>In the incubation process of domestic avian eggs, the development of the embryo is mainly influenced by the physical microenvironment around the egg. Only small spatiotemporal deviations in the optimal incubator <span class="hlt">air</span> temperature are allowed to optimize hatchability and hatchling quality. The temperature of the embryo depends on 3 factors: (1) the <span class="hlt">air</span> temperature, (2) the <span class="hlt">exchange</span> of heat between the egg and its microenvironment and (3) the time-variable heat production of the embryo. Theoretical estimates on the heat <span class="hlt">exchange</span> between an egg and its physical microenvironment are approximated using equations that assume an approximate spherical shape for eggs. The objective of this research was to determine the heat transfer between the eggshell and its microenvironment and then compare this value to various theoretical estimates. By using experimental data, the overall and the convective heat transfer coefficients were determined as a function of heat production, <span class="hlt">air</span> humidity, <span class="hlt">air</span> speed, and <span class="hlt">air</span> temperature. Heat transfer was not affected by <span class="hlt">air</span> humidity but solely by <span class="hlt">air</span> temperature, embryonic heat generation, and <span class="hlt">air</span> speed and flow around eggs. Also, heat transfer in forced-<span class="hlt">air</span> incubators occurs mainly by convective heat loss, which is dependent on the speed of airflow. A vertical airflow is more efficient than a horizontal airflow in transferring heat from the egg. We showed that describing an egg as a sphere underestimated convective heat transfer by 33% and was, therefore, too simplistic to accurately assess actual heat transfer from real eggs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010NuPhA.847...24R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010NuPhA.847...24R"><span>Macro-microscopic <span class="hlt">mass</span> formulae and nuclear <span class="hlt">mass</span> predictions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Royer, G.; Guilbaud, M.; Onillon, A.</p> <p>2010-12-01</p> <p>Different <span class="hlt">mass</span> formulae derived from the liquid drop model and the pairing and shell energies of the Thomas-Fermi model have been studied and compared. They include or not the diffuseness correction to the Coulomb energy, the charge <span class="hlt">exchange</span> correction term, the curvature energy, different forms of the Wigner term and powers of the relative neutron excess I=(N-Z)/A. Their coefficients have been determined by a least square fitting procedure to 2027 experimental atomic <span class="hlt">masses</span> (G. Audi et al. (2003) [1]). The Coulomb diffuseness correction Z/A term or the charge <span class="hlt">exchange</span> correction Z/A term plays the main role to improve the accuracy of the <span class="hlt">mass</span> formula. The Wigner term and the curvature energy can also be used separately but their coefficients are very unstable. The different fits lead to a surface energy coefficient of around 17-18 MeV. A large equivalent rms radius ( r=1.22-1.24 fm) or a shorter central radius may be used. An rms deviation of 0.54 MeV can be reached between the experimental and theoretical <span class="hlt">masses</span>. The remaining differences come probably mainly from the determination of the shell and pairing energies. <span class="hlt">Mass</span> predictions of selected expressions have been compared to 161 new experimental <span class="hlt">masses</span> and the correct agreement allows to provide extrapolations to <span class="hlt">masses</span> of 656 selected exotic nuclei.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.9754G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.9754G"><span>Changes in water <span class="hlt">mass</span> <span class="hlt">exchange</span> between the NW shelf areas and the North Atlantic and their impact on nutrient/carbon cycling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gröger, Matthias; Maier-Reimer, Ernst; Mikolajewicz, Uwe; Segschneider, Joachim; Sein, Dimitry</p> <p>2010-05-01</p> <p>Despite their comparatively small extension on a global scale, shelf areas are of interest for several economic reasons and climatic processes related to nutrient cycling, sea food supply, and biological productivity. Moreover, they constitute an important interface for nutrients, pollutants and freshwater on their pathway from the continents to the open ocean. This modelling study aims to investigate the spatial and temporal variability of water <span class="hlt">mass</span> <span class="hlt">exchange</span> between the North Atlantic and the NW European shelf and their impact on nutrient/carbon cycling and biological productivity. For this, a new modeling approach has been set up which bridges the gap between pure shelf models where water <span class="hlt">mass</span> transports across the model domain too strongly depend on the formulation of open boundaries and global models suffering under their too coarse resolution in shelf regions. The new model consists of the global ocean and carbon cycle model MPIOM/HAMOCC with strongly increased resolution in the North Sea and the North Atlantic coupled to the regional atmosphere model REMO. The model takes the full luni-solar tides into account. It includes further a 12 layer sediment module with the relevant pore water chemistry. The main focus lies on the governing mechanisms of water <span class="hlt">mass</span> <span class="hlt">exchange</span> across the shelf break and the imprint on shelf biogeochemistry. For this, artificial tracers with a prescribed decay rate have been implemented to distinguish waters arriving from polar and shelf regions and those that originate from the tropics. Experiments were carried out for the years 1948 - 2007. The relationship to larger scale circulation patterns like the position and variability of the subtropical and subpolar gyres is analyzed. The water <span class="hlt">mass</span> <span class="hlt">exchange</span> is analyzed with respect to the nutrient concentration and productivity on the European shelf areas. The implementation of tides leads to an enhanced vertical mixing which causes lower sea surface temperatures compared to simulations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4603868','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4603868"><span>Neonatal Presentation of an <span class="hlt">Air</span>-Filled Neck <span class="hlt">Mass</span> that Enlarges with Valsalva: A Case Report</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Patel, Jasminkumar Bharatbhai; Kilbride, Howard; Paulson, Lorien</p> <p>2015-01-01</p> <p>Branchial cleft cysts are common causes of congenital neck <span class="hlt">masses</span> in the pediatric population. However, neonatal presentation of branchial cleft cysts is uncommon, but recognizable secondary to acute respiratory distress from airway compression or complications secondary to infection. We report a 1-day-old infant presenting with an <span class="hlt">air</span>-filled neck <span class="hlt">mass</span> that enlarged with Valsalva and was not associated with respiratory distress. The infant was found to have a third branchial cleft cyst with an internal opening into the pyriform sinus. The cyst was conservatively managed with endoscopic surgical decompression and cauterization of the tract and opening. We review the embryology of branchial cleft cysts and current management. PMID:26495186</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28640914','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28640914"><span>Kinetic analysis of an anion <span class="hlt">exchange</span> absorbent for CO2 capture from ambient <span class="hlt">air</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shi, Xiaoyang; Li, Qibin; Wang, Tao; Lackner, Klaus S</p> <p>2017-01-01</p> <p>This study reports a preparation method of a new moisture swing sorbent for CO2 capture from <span class="hlt">air</span>. The new sorbent components include ion <span class="hlt">exchange</span> resin (IER) and polyvinyl chloride (PVC) as a binder. The IER can absorb CO2 when surrounding is dry and release CO2 when surrounding is wet. The manuscript presents the studies of membrane structure, kinetic model of absorption process, performance of desorption process and the diffusivity of water molecules in the CO2 absorbent. It has been proved that the kinetic performance of CO2 absorption/desorption can be improved by using thin binder and hot water treatment. The fast kinetics of P-100-90C absorbent is due to the thin PVC binder, and high diffusion rate of H2O molecules in the sample. The impressive is this new CO2 absorbent has the fastest CO2 absorption rate among all absorbents which have been reported by other up-to-date literatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5480984','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5480984"><span>Kinetic analysis of an anion <span class="hlt">exchange</span> absorbent for CO2 capture from ambient <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shi, Xiaoyang; Li, Qibin; Lackner, Klaus S.</p> <p>2017-01-01</p> <p>This study reports a preparation method of a new moisture swing sorbent for CO2 capture from <span class="hlt">air</span>. The new sorbent components include ion <span class="hlt">exchange</span> resin (IER) and polyvinyl chloride (PVC) as a binder. The IER can absorb CO2 when surrounding is dry and release CO2 when surrounding is wet. The manuscript presents the studies of membrane structure, kinetic model of absorption process, performance of desorption process and the diffusivity of water molecules in the CO2 absorbent. It has been proved that the kinetic performance of CO2 absorption/desorption can be improved by using thin binder and hot water treatment. The fast kinetics of P-100-90C absorbent is due to the thin PVC binder, and high diffusion rate of H2O molecules in the sample. The impressive is this new CO2 absorbent has the fastest CO2 absorption rate among all absorbents which have been reported by other up-to-date literatures. PMID:28640914</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24462236','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24462236"><span>Polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) in the equatorial Indian Ocean: temporal trend, continental outflow and <span class="hlt">air</span>-water <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Yumei; Li, Jun; Xu, Yue; Xu, Weihai; Cheng, Zhineng; Liu, Junwen; Wang, Yan; Tian, Chongguo; Luo, Chunling; Zhang, Gan</p> <p>2014-03-15</p> <p>Nineteen pairs of <span class="hlt">air</span> and seawater samples collected from the equatorial Indian Ocean onboard the Shiyan I from 4/2011 to 5/2011 were analyzed for PCBs and HCB. Gaseous concentrations of ∑(ICES)PCBs (ICES: International Council for the Exploration of the Seas) and HCB were lower than previous data over the study area. <span class="hlt">Air</span> samples collected near the coast had higher levels of PCBs relative to those collected in the open ocean, which may be influenced by proximity to source regions and <span class="hlt">air</span> <span class="hlt">mass</span> origins. Dissolved concentrations of ∑(ICES)PCBs and HCB were 1.4-14 pg L⁻¹ and 0.94-13 pg L⁻¹, with the highest concentrations in the sample collected from Strait of Malacca. Fugacity fractions suggest volatilization of PCBs and HCB from the seawater to <span class="hlt">air</span> during the cruise, with fluxes of 0.45-34 ng m⁻² d⁻¹ and 0.36-18 ng m⁻² d⁻¹, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AtmEn..42..757G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AtmEn..42..757G"><span>Impact of ventilation scenario on <span class="hlt">air</span> <span class="hlt">exchange</span> rates and on indoor particle number concentrations in an <span class="hlt">air</span>-conditioned classroom</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, H.; Morawska, L.; He, C.; Gilbert, D.</p> <p></p> <p>A 2-week intensive measurement campaign of indoor and outdoor <span class="hlt">air</span> pollution was carried out in September 2006, in a primary school to investigate indoor-outdoor correlations of particle number (PN) concentrations, and the impact of <span class="hlt">air</span> <span class="hlt">exchange</span> rate (ACH) on the indoor PN concentration. The ACHs in the classroom for different conditions associated with window opening and the operational status of <span class="hlt">air</span> conditioners (A/C) and fans were tested. As expected, the lowest ACH (0.12 h -1) was found when the windows were closed and A/C and fans were off. In contrast, the highest ACH (7.92 h -1) was observed when the windows were opened and A/C and fans were all on. The analysis of the PN I/ O ratios at different ACHs in the absence of indoor sources indicates that the mean I/ O ratio was 0.621±0.007 (mean±95% confidence interval) when the windows were closed, and A/C and fans were off; 0.524±0.023 when windows were closed, fans were off and A/C was on; and 0.502±0.029 when windows were closed, A/C was off and fans were on. To further understand the relationship between indoor and outdoor PN concentrations, the impact of outdoor PN concentration on I/ O ratios at different ACHs was investigated. It was found that the relationship between outdoor PN concentration and the I/ O ratio at different ACHs followed a power trendline with an equation of I/ O ratio= A PN out-b ( A and b are coefficients, PN out is outdoor PN concentration), suggesting that the penetration efficiency decreased with increasing outdoor PN concentration. It is the first time we found that when the outdoor PN concentration increased there was an associated increase in the concentration of nano-particles, which have been demonstrated to have higher deposition rates and lower penetration efficiencies. Based on the above equation, the study also showed a significant effect of ACH on indoor PN concentrations under stable outdoor PN concentrations. In general, the higher the ACH was, the lower the indoor PN</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/homeland-security-research/epa-air-method-toxic-organics-15-15-determination-volatile-organic','PESTICIDES'); return false;" href="https://www.epa.gov/homeland-security-research/epa-air-method-toxic-organics-15-15-determination-volatile-organic"><span>EPA <span class="hlt">Air</span> Method, Toxic Organics - 15 (TO-15): Determination of Volatile Organic Compounds (VOCs) in <span class="hlt">Air</span> Collected in Specially-Prepared Canisters and Analyzed by Gas Chromatography/<span class="hlt">Mass</span> Spectrometry (GC/MS)</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Method T)-15 describes procedures for for preparation and analysis of <span class="hlt">air</span> samples containing volatile organic compounds collected in specially-prepared canisters, using gas chromatography-<span class="hlt">mass</span> spectrometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JGRD..10923S20D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JGRD..10923S20D"><span>Chemical composition of <span class="hlt">air</span> <span class="hlt">masses</span> transported from Asia to the U.S. West Coast during ITCT 2K2: Fossil fuel combustion versus biomass-burning signatures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Gouw, J. A.; Cooper, O. R.; Warneke, C.; Hudson, P. K.; Fehsenfeld, F. C.; Holloway, J. S.; Hübler, G.; Nicks, D. K., Jr.; Nowak, J. B.; Parrish, D. D.; Ryerson, T. B.; Atlas, E. L.; Donnelly, S. G.; Schauffler, S. M.; Stroud, V.; Johnson, K.; Carmichael, G. R.; Streets, D. G.</p> <p>2004-12-01</p> <p>As part of the Intercontinental Transport and Chemical Transformation experiment in 2002 (ITCT 2K2), a National Oceanic and Atmospheric Administration (NOAA) WP-3D research aircraft was used to study the long-range transport of Asian <span class="hlt">air</span> <span class="hlt">masses</span> toward the west coast of North America. During research flights on 5 and 17 May, strong enhancements of carbon monoxide (CO) and other species were observed in <span class="hlt">air</span> <span class="hlt">masses</span> that had been transported from Asia. The hydrocarbon composition of the <span class="hlt">air</span> <span class="hlt">masses</span> indicated that the highest CO levels were related to fossil fuel use. During the flights on 5 and 17 May and other days, the levels of several biomass-burning indicators increased with altitude. This was true for acetonitrile (CH3CN), methyl chloride (CH3Cl), the ratio of acetylene (C2H2) to propane (C3H8), and, on May 5, the percentage of particles measured by the particle analysis by laser <span class="hlt">mass</span> spectrometry (PALMS) instrument that were attributed to biomass burning based on their carbon and potassium content. An ensemble of back-trajectories, calculated from the U.S. west coast over a range of latitudes and altitudes for the entire ITCT 2K2 period, showed that <span class="hlt">air</span> <span class="hlt">masses</span> from Southeast Asia and China were generally observed at higher altitudes than <span class="hlt">air</span> from Japan and Korea. Emission inventories estimate the contribution of biomass burning to the total emissions to be low for Japan and Korea, higher for China, and the highest for Southeast Asia. Combined with the origin of the <span class="hlt">air</span> <span class="hlt">masses</span> versus altitude, this qualitatively explains the increase with altitude, averaged over the whole ITCT 2K2 period, of the different biomass-burning indicators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27882886','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27882886"><span>Technical note: <span class="hlt">Air</span> compared to nitrogen as nebulizing and drying gases for electrospray ionization <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mielczarek, P; Silberring, J; Smoluch, M</p> <p></p> <p>In the present study we tested the application of compressed <span class="hlt">air</span> instead of pure nitrogen as the nebulizing and drying gas, and its influence on the quality of electrospray ionization (ESI) <span class="hlt">mass</span> spectra. The intensities of the signals corresponding to protonated molecules were significantly (twice) higher when <span class="hlt">air</span> was used. Inspection of signal-to-noise (S/N) ratios revealed that, in both cases, sensitivity was comparable. A higher ion abundance after the application of compressed <span class="hlt">air</span> was followed by a higher background. Another potential risk of using <span class="hlt">air</span> in the ESI source is the possibility for sample oxidation due to the presence of oxygen. To test this, we selected five easily oxidizing compounds to verify their susceptibility to oxidation. In particular, the presence of methionine was of interest. For all the compounds studied, no oxidation was observed. Amodiaquine oxidizes spontaneously in water solutions and its oxidized form can be detected a few hours after preparation. Direct comparison of the spectra where nitrogen was used with the corresponding spectra obtained when <span class="hlt">air</span> was applied did not show significant differences. The only distinction was slightly different patterns of adducts when <span class="hlt">air</span> was used. The difference concerns acetonitrile, which forms higher signals when <span class="hlt">air</span> is the nebulizing gas. It is also important that the replacement of nitrogen with <span class="hlt">air</span> does not affect quantitative data. The prepared calibration curves also visualize an intensity twice as high (independent of concentration within tested range) of the signal where <span class="hlt">air</span> was applied. We have used our system continuously for three months with <span class="hlt">air</span> as the nebulizing and drying gas and have not noticed any unexpected signal deterioration caused by additional source contamination from the <span class="hlt">air</span>. Moreover, compressed <span class="hlt">air</span> is much cheaper and easily available using oil-free compressors or pumps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JASMS..29..174H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JASMS..29..174H"><span>Probing Conformational Dynamics of Tau Protein by Hydrogen/Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Richard Y.-C.; Iacob, Roxana E.; Sankaranarayanan, Sethu; Yang, Ling; Ahlijanian, Michael; Tao, Li; Tymiak, Adrienne A.; Chen, Guodong</p> <p>2018-01-01</p> <p>Fibrillization of the microtubule-associated protein tau has been recognized as one of the signature pathologies of the nervous system in Alzheimer's disease, progressive supranuclear palsy, and other tauopathies. The conformational transition of tau in the fibrillization process, tau monomer to soluble aggregates to fibrils in particular, remains unclear. Here we report on the use of hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) in combination with other biochemical approaches, including Thioflavin S fluorescence measurements, enzyme-linked immunosorbent assay (ELISA), and Western blotting to understand the heparin-induced tau's fibrillization. HDX-MS studies including anti-tau antibody epitope mapping experiments provided molecular level details of the full-length tau's conformational dynamics and its regional solvent accessibility upon soluble aggregates formation. The results demonstrate that R3 region in the full-length tau's microtubule binding repeat region (MTBR) is stabilized in the aggregation process, leaving both N and C terminal regions to be solvent exposed in the soluble aggregates and fibrils. The findings also illustrate the practical utility of orthogonal analytical methodologies for the characterization of protein higher order structure. [Figure not available: see fulltext.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PrOce.144...15W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PrOce.144...15W"><span>Biofilm-like properties of the sea surface and predicted effects on <span class="hlt">air</span>-sea CO2 <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wurl, Oliver; Stolle, Christian; Van Thuoc, Chu; The Thu, Pham; Mari, Xavier</p> <p>2016-05-01</p> <p>Because the sea surface controls various interactions between the ocean and the atmosphere, it has a profound function for marine biogeochemistry and climate regulation. The sea surface is the gateway for the <span class="hlt">exchange</span> of climate-relevant gases, heat and particles. Thus, in order to determine how the ocean and the atmosphere interact and respond to environmental changes on a global scale, the characterization and understanding of the sea surface are essential. The uppermost part of the water column is defined as the sea-surface microlayer and experiences strong spatial and temporal dynamics, mainly due to meteorological forcing. Wave-damped areas at the sea surface are caused by the accumulation of surface-active organic material and are defined as slicks. Natural slicks are observed frequently but their biogeochemical properties are poorly understood. In the present study, we found up to 40 times more transparent exopolymer particles (TEP), the foundation of any biofilm, in slicks compared to the underlying bulk water at multiple stations in the North Pacific, South China Sea, and Baltic Sea. We found a significant lower enrichment of TEP (up to 6) in non-slick sea surfaces compared to its underlying bulk water. Moreover, slicks were characterized by a large microbial biomass, another shared feature with conventional biofilms on solid surfaces. Compared to non-slick samples (avg. pairwise similarity of 70%), the community composition of bacteria in slicks was increasingly (avg. pairwise similarity of 45%) different from bulk water communities, indicating that the TEP-matrix creates specific environments for its inhabitants. We, therefore, conclude that slicks can feature biofilm-like properties with the excessive accumulation of particles and microbes. We also assessed the potential distribution and frequency of slick-formation in coastal and oceanic regions, and their effect on <span class="hlt">air</span>-sea CO2 <span class="hlt">exchange</span> based on literature data. We estimate that slicks can reduce CO2</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1710370B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1710370B"><span>Evidence for widespread tropospheric Cl chemistry in free tropospheric <span class="hlt">air</span> <span class="hlt">masses</span> from the South China Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, Angela K.; Sauvage, Carina; Thorenz, Ute R.; Brenninkmeijer, Carl A. M.; Oram, David E.; van Velthoven, Peter; Zahn, Andreas; Williams, Jonathan</p> <p>2015-04-01</p> <p>While the primary global atmospheric oxidant is the hydroxyl radical (OH), under certain circumstances chlorine radicals (Cl) can compete with OH and perturb the oxidative cycles of the troposphere. During flights between Bangkok, Thailand and Kuala Lumpur, Malaysia conducted over two fall/winter seasons (November 2012 - March 2013 and November 2013 - January 2014) the IAGOS-CARIBIC (www.caribic-atmospheric.com) observatory consistently encountered free tropospheric <span class="hlt">air</span> <span class="hlt">masses</span> (9-11 km) originating over the South China Sea which had non-methane hydrocarbon (NMHC) signatures characteristic of processing by Cl. These signatures were observed in November and December of both years, but were not seen in other months, suggesting that oxidation by Cl is a persistent seasonal feature in this region. These Cl signatures were observed over a range of ~1500 km indicating a large-scale phenomenon. In this region, where transport patterns facilitate global redistribution of pollutants and persistent deep convection creates a fast-track for cross-tropopause transport, there exists the potential for regional chemistry to have impacts further afield. Here we use observed relationships between NMHCs to estimate the significance and magnitude of Cl oxidation in this region. From the relative depletions of NMHCs in these <span class="hlt">air</span> <span class="hlt">masses</span> we infer OH to Cl ratios of 83±28 to 139±40 [OH]/[Cl], which we believe represents an upper limit, based on the technique employed. At a predicted average [OH] of 1.5×106 OH cm-3 this corresponds to an average (minimum) [Cl] exposure of 1-2×104 Cl cm-3 during <span class="hlt">air</span> <span class="hlt">mass</span> transport. Lastly, in addition to estimating Cl abundances we have used IAGOS-CARIBIC observations to elucidate whether the origin of this Cl is predominantly natural or anthropogenic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28495075','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28495075"><span>Relationship Between Chronic Obstructive Pulmonary Disease and <span class="hlt">Air</span> Pollutants Depending on the Origin and Trajectory of <span class="hlt">Air</span> <span class="hlt">Masses</span> in the North of Spain.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santurtún, Ana; Rasilla, Domingo F; Riancho, Leyre; Zarrabeitia, María T</p> <p>2017-11-01</p> <p>Chronic obstructive pulmonary disease (COPD) is a common respiratory condition and one of the leading causes of death. Our aim was to analyze the association between emergency room visits due to this disease and meteorological variables and atmospheric contaminant levels in Santander, depending on the origin and trajectory of <span class="hlt">air</span> <span class="hlt">masses</span>. Data from emergency room visits at Hospital Marqués de Valdecilla were collected on a daily basis during an 8-year period. Data on concentrations of the main atmospheric pollutants and meteorological variables were also recorded.Retrotrajectories leading to Santander at a height of1,500 meters above sea level were then calculated. Finally, a correlation model was produced to evaluate the effect of the contaminants on emergency visitsdue to COPD. There is a direct association between PM 10 levels and the number of visits to the emergency room due to COPD. For every 10μg/m3 increase in pollutantlevels, emergency visitsincrease by3.34% (p=0.00005), and thiseffect is enhanced in individualsover 74 years of age. This effect is heightened when PM10 levels depend on <span class="hlt">air</span> <span class="hlt">masses</span> from the South and when <span class="hlt">air</span> recirculation occurs. There is no association betweenother pollutants and the number of visits to the emergency room. Exposure to high levels of PM10 causes exacerbations in COPD patients. By studying the atmospheric circulation pattern, we can predict whether PM10 levels will be inappropriately high, and we can also obtain information about the particle components. Copyright © 2017 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890006529','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890006529"><span>A piloted simulation study of data link ATC message <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Waller, Marvin C.; Lohr, Gary W.</p> <p>1989-01-01</p> <p>Data link <span class="hlt">Air</span> Traffic Control (ATC) and <span class="hlt">Air</span> Traffic Service (ATS) message and data <span class="hlt">exchange</span> offers the potential benefits of increased flight safety and efficiency by reducing communication errors and allowing more information to be transferred between aircraft and ground facilities. Digital communication also presents an opportunity to relieve the overloading of ATC radio frequencies which hampers message <span class="hlt">exchange</span> during peak traffic hours in many busy terminal areas. A piloted simulation study to develop pilot factor guidelines and assess potential flight crew benefits and liabilities from using data link ATC message <span class="hlt">exchange</span> was completed. The data link ATC message <span class="hlt">exchange</span> concept, implemented on an existing navigation computer Control Display Unit (CDU) required maintaining a voice radio telephone link with an appropriate ATC facility. Flight crew comments, scanning behavior, and measurements of time spent in ATC communication activities for data link ATC message <span class="hlt">exchange</span> were compared to similar measures for simulated conventional voice radio operations. The results show crew preference for the quieter flight deck environment and a perception of lower communication workload.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780000481&hterms=heater+Solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dheater%2BSolar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780000481&hterms=heater+Solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dheater%2BSolar"><span>Solar-powered hot-<span class="hlt">air</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1979-01-01</p> <p>Solar-powered <span class="hlt">air</span> heater supplies part or all of space heating requirements of residential or commercial buildings and is interfaced with <span class="hlt">air</span> to water heat <span class="hlt">exchanger</span> to heat domestic hot water. System has potential application in drying agricultural products such as cotton, lumber, corn, grains, and peanuts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989PhDT........36B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989PhDT........36B"><span>Compact heat and <span class="hlt">mass</span> <span class="hlt">exchangers</span> of the plate fin type in thermal sorption systems: Application in an absorption heat pump with the working pair CH3OH-LiBr/ZnBr2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Becker, Harry</p> <p></p> <p>The possible application of Compact Heat and <span class="hlt">Mass</span> <span class="hlt">Exchangers</span> (CHME) in a gas fired Absorption Heat Pump (AHP) for domestic heating is studied. The above mentioned heat and <span class="hlt">mass</span> <span class="hlt">exchangers</span> are of the plate type. The space between the parallel and plain plates is filled up with corrugated plates of a certain height. The plain and finned plates are stacked and welded together. This gives a heat and <span class="hlt">mass</span> <span class="hlt">exchanger</span> which is very compact, expressed by a high area density (m2/m3). This leads to heat and <span class="hlt">mass</span> transfer processes with small temperature and concentration differences. For testing purposes a pilot plant was built using the above type of components in order to test their heat and/or <span class="hlt">mass</span> transfer performance. Only the generator is of the Shell And Tube (SAT) type. As the working pair, CH3OH - LiBr/ ZnBr2 was chosen, with the alcohol as the solvent and the salt mixture as the absorbent. This leads to sub atmospheric working pressures with only solvent in the vapor phase. Three series of experiments have been carried out, during which the input parameters were varied over a certain range. It is concluded that the plate fin CHMES are very suitable for application in an AHP for domestic heating purposes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRD..11123S62M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRD..11123S62M"><span>Establishing Lagrangian connections between observations within <span class="hlt">air</span> <span class="hlt">masses</span> crossing the Atlantic during the International Consortium for Atmospheric Research on Transport and Transformation experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Methven, J.; Arnold, S. R.; Stohl, A.; Evans, M. J.; Avery, M.; Law, K.; Lewis, A. C.; Monks, P. S.; Parrish, D. D.; Reeves, C. E.; Schlager, H.; Atlas, E.; Blake, D. R.; Coe, H.; Crosier, J.; Flocke, F. M.; Holloway, J. S.; Hopkins, J. R.; McQuaid, J.; Purvis, R.; Rappenglück, B.; Singh, H. B.; Watson, N. M.; Whalley, L. K.; Williams, P. I.</p> <p>2006-12-01</p> <p>The ITCT-Lagrangian-2K4 (Intercontinental Transport and Chemical Transformation) experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of <span class="hlt">air</span> <span class="hlt">masses</span> in the free troposphere away from emissions. To this end, attempts were made to intercept and sample <span class="hlt">air</span> <span class="hlt">masses</span> several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts from two Lagrangian models that were used to direct the aircraft into target <span class="hlt">air</span> <span class="hlt">masses</span>. A novel technique then identifies Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole <span class="hlt">air</span> samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these "coincident matches" is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown, and the downwind minus upwind differences in tracers are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.3813H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.3813H"><span>Influence of current velocity and wind speed on <span class="hlt">air</span>-water gas <span class="hlt">exchange</span> in a mangrove estuary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ho, David T.; Coffineau, Nathalie; Hickman, Benjamin; Chow, Nicholas; Koffman, Tobias; Schlosser, Peter</p> <p>2016-04-01</p> <p>Knowledge of <span class="hlt">air</span>-water gas transfer velocities and water residence times is necessary to study the fate of mangrove derived carbon exported into surrounding estuaries and ultimately to determine carbon balances in mangrove ecosystems. For the first time, the 3He/SF6 dual tracer technique, which has been proven to be a powerful tool to determine gas transfer velocities in the ocean, is applied to Shark River, an estuary situated in the largest contiguous mangrove forest in North America. The mean gas transfer velocity was 3.3 ± 0.2 cm h-1 during the experiment, with a water residence time of 16.5 ± 2.0 days. We propose a gas <span class="hlt">exchange</span> parameterization that takes into account the major sources of turbulence in the estuary (i.e., bottom generated shear and wind stress).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950044372&hterms=motes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmotes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950044372&hterms=motes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmotes"><span>Characteristics of stratosphere-troposphere <span class="hlt">exchange</span> in a general circulation model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mote, Philip W.; Holton, James R.; Boville, Byron A.</p> <p>1994-01-01</p> <p>In this study we examine <span class="hlt">mass</span> <span class="hlt">exchange</span>, water vapor <span class="hlt">exchange</span>, and the behavior of idealized tracers and parcels to diagnose Stratosphere-Troposphere <span class="hlt">Exchange</span> (STE) in the National Center for Atmospheric Research (NCAR) General Circulation Model (GCM), the Community Climate Model (CCM2). The CCM2 correctly represents the seasonality of <span class="hlt">mass</span> <span class="hlt">exchange</span> across 100 hPa, but values are uniformly too strong. Water vapor, however, indicates that tropical STE is not well represented in the CCM2; even though mean tropopause temperatures are colder than observed, the lower stratosphere is too moist. Most net <span class="hlt">mass</span> flux occurs at water vapor mixing ratios of about 4-5 parts per million by volume (ppmv), about 1 ppmv too moist. Vertical resolution has little impact on the nature of tropical STE. In midlatitudes, CCM2 more successfully represents STE, which occurs in developing baroclinic waves and stationary anticyclones. <span class="hlt">Exchange</span> from troposphere to stratosphere does occur but only influences the lowest few kilometers of the extratropical stratosphere, even for tracers with large vertical gradients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24222707','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24222707"><span>Ex vivo assessment and validation of water <span class="hlt">exchange</span> performance of 23 heat and moisture <span class="hlt">exchangers</span> for laryngectomized patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van den Boer, Cindy; Muller, Sara H; Vincent, Andrew D; van den Brekel, Michiel W M; Hilgers, Frans J M</p> <p>2014-08-01</p> <p>Breathing through a tracheostoma results in insufficient warming and humidification of the inspired <span class="hlt">air</span>. This loss of <span class="hlt">air</span> conditioning, especially humidification, can be partially restored with the application of a heat and moisture <span class="hlt">exchanger</span> (HME) over the tracheostoma. For medical professionals, it is not easy to judge differences in water <span class="hlt">exchange</span> performance of various HMEs owing to the lack of universal outcome measures. This study has three aims: assessment of the water <span class="hlt">exchange</span> performance of commercially available HMEs for laryngectomized patients, validation of these results with absolute humidity outcomes, and assessment of the role of hygroscopic salt present in some of the tested HMEs. Measurements of weight and absolute humidity at end inspiration and end expiration at different breathing volumes of a healthy volunteer were performed using a microbalance and humidity sensor. Twenty-three HMEs from 6 different manufacturers were tested. Associations were determined between core weight, weight change, breathing volume, and absolute humidity, using both linear and nonlinear mixed effects models. Water <span class="hlt">exchange</span> of the 23 HMEs at a breathing volume of 0.5 L varies between 0.5 and 3.6 mg. Both water <span class="hlt">exchange</span> and wet core weight correlate strongly with the end-inspiratory absolute humidity values (r2 =0.89/0.87). Hygroscopic salt increases core weight. The 23 tested HMEs for laryngectomized patients show wide variation in water <span class="hlt">exchange</span> performance. Water <span class="hlt">exchange</span> correlates well with the end-inspiratory absolute humidity outcome, which validates the ex vivo weight change method. Wet core weight is a predictor of HME performance. Hygroscopic salt increases the weight of the core material. The results of this study can help medical professionals to obtain a more founded opinion about the performance of available HMEs for pulmonary rehabilitation in laryngectomized patients, and allow them to make an informed decision about which HME type to use.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870048193&hterms=concentration+pH+ammonium+sulfate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dconcentration%2B%252BpH%2B%252B%2Bammonium%2Bsulfate','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870048193&hterms=concentration+pH+ammonium+sulfate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dconcentration%2B%252BpH%2B%252B%2Bammonium%2Bsulfate"><span>Aerosols in polluted versus nonpolluted <span class="hlt">air</span> <span class="hlt">masses</span> Long-range transport and effects on clouds</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pueschel, R. F.; Van Valin, C. C.; Castillo, R. C.; Kadlecek, J. A.; Ganor, E.</p> <p>1986-01-01</p> <p>To assess the influence of anthropogenic aerosols on the physics and chemistry of clouds in the northeastern United States, aerosol and cloud-drop size distributions, elemental composition of aerosols as a function of size, and ionic content of cloud water were measured on Whiteface Mountain, NY, during the summers of 1981 and 1982. In several case studies, the data were cross-correlated with different <span class="hlt">air</span> <span class="hlt">mass</span> types - background continental, polluted continental, and maritime - that were advected to the sampling site. The results are the following: (1) Anthropogenic sources hundreds of kilometers upwind cause the small-particle (accumulation) mode number to increase from hundreds of thousands per cubic centimeter and the <span class="hlt">mass</span> loading to increase from a few to several tens of micrograms per cubic meter, mostly in the form of sulfur aerosols. (2) A significant fraction of anthropogenic sulfur appears to act as cloud condensation nuclei (CCN) to affect the cloud drop concentration. (3) Clouds in Atlantic maritime <span class="hlt">air</span> <span class="hlt">masses</span> have cloud drop spectra that are markedly different from those measured in continental clouds. The drop concentration is significantly lower, and the drop size spectra are heavily skewed toward large drops. (4) Effects of anthropogenic pollutants on cloud water ionic composition are an increase of nitrate by a factor of 50, an increase of sulfate by more than one order of magnitude, and an increase of ammonium ion by a factor of 7. The net effect of the changes in ionic concentrations is an increase in cloud water acidity. An anion deficit even in maritime clouds suggests an unknown, possibly biogenic, source that could be responsible for a pH below neutral, which is frequently observed in nonpolluted clouds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ACP....1311073B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ACP....1311073B"><span><span class="hlt">Air</span>-sea dimethylsulfide (DMS) gas transfer in the North Atlantic: evidence for limited interfacial gas <span class="hlt">exchange</span> at high wind speed</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bell, T. G.; De Bruyn, W.; Miller, S. D.; Ward, B.; Christensen, K.; Saltzman, E. S.</p> <p>2013-11-01</p> <p>Shipboard measurements of eddy covariance dimethylsulfide (DMS) <span class="hlt">air</span>-sea fluxes and seawater concentration were carried out in the North Atlantic bloom region in June/July 2011. Gas transfer coefficients (k660) show a linear dependence on mean horizontal wind speed at wind speeds up to 11 m s-1. At higher wind speeds the relationship between k660 and wind speed weakens. At high winds, measured DMS fluxes were lower than predicted based on the linear relationship between wind speed and interfacial stress extrapolated from low to intermediate wind speeds. In contrast, the transfer coefficient for sensible heat did not exhibit this effect. The apparent suppression of <span class="hlt">air</span>-sea gas flux at higher wind speeds appears to be related to sea state, as determined from shipboard wave measurements. These observations are consistent with the idea that long waves suppress near-surface water-side turbulence, and decrease interfacial gas transfer. This effect may be more easily observed for DMS than for less soluble gases, such as CO2, because the <span class="hlt">air</span>-sea <span class="hlt">exchange</span> of DMS is controlled by interfacial rather than bubble-mediated gas transfer under high wind speed conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1220375','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1220375"><span>Technology Solutions Case Study: Foundation Heat <span class="hlt">Exchanger</span>, Oak Ridge, Tennessee</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>None</p> <p>2014-03-01</p> <p>The foundation heat <span class="hlt">exchanger</span>, developed by Oak Ridge National Laboratory, is a new concept for a cost-effective horizontal ground heat <span class="hlt">exchanger</span> that can be connected to water-to-water or water-to-<span class="hlt">air</span> heat pump systems for space conditioning as well as domestic water heating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21953973','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21953973"><span>Metabolite identification of triptolide by data-dependent accurate <span class="hlt">mass</span> spectrometric analysis in combination with online hydrogen/deuterium <span class="hlt">exchange</span> and multiple data-mining techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Du, Fuying; Liu, Ting; Liu, Tian; Wang, Yongwei; Wan, Yakun; Xing, Jie</p> <p>2011-10-30</p> <p>Triptolide (TP), the primary active component of the herbal medicine Tripterygium wilfordii Hook F, has shown promising antileukemic and anti-inflammatory activity. The pharmacokinetic profile of TP indicates an extensive metabolic elimination in vivo; however, its metabolic data is rarely available partly because of the difficulty in identifying it due to the absence of appropriate ultraviolet chromophores in the structure and the presence of endogenous interferences in biological samples. In the present study, the biotransformation of TP was investigated by improved data-dependent accurate <span class="hlt">mass</span> spectrometric analysis, using an LTQ/Orbitrap hybrid <span class="hlt">mass</span> spectrometer in conjunction with the online hydrogen (H)/deuterium (D) <span class="hlt">exchange</span> technique for rapid structural characterization. Accurate full-scan MS and MS/MS data were processed with multiple post-acquisition data-mining techniques, which were complementary and effective in detecting both common and uncommon metabolites from biological matrices. As a result, 38 phase I, 9 phase II and 8 N-acetylcysteine (NAC) metabolites of TP were found in rat urine. Accurate MS/MS data were used to support assignments of metabolite structures, and online H/D <span class="hlt">exchange</span> experiments provided additional evidence for <span class="hlt">exchangeable</span> hydrogen atoms in the structure. The results showed the main phase I metabolic pathways of TP are hydroxylation, hydrolysis and desaturation, and the resulting metabolites subsequently undergo phase II processes. The presence of NAC conjugates indicated the capability of TP to form reactive intermediate species. This study also demonstrated the effectiveness of LC/HR-MS(n) in combination with multiple post-acquisition data-mining methods and the online H/D <span class="hlt">exchange</span> technique for the rapid identification of drug metabolites. Copyright © 2011 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/834477','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/834477"><span>Chemical-Specific Representation of <span class="hlt">Air</span>-Soil <span class="hlt">Exchange</span> and Soil Penetration in Regional Multimedia Models</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>McKone, T.E.; Bennett, D.H.</p> <p>2002-08-01</p> <p>In multimedia <span class="hlt">mass</span>-balance models, the soil compartment is an important sink as well as a conduit for transfers to vegetation and shallow groundwater. Here a novel approach for constructing soil transport algorithms for multimedia fate models is developed and evaluated. The resulting algorithms account for diffusion in gas and liquid components; advection in gas, liquid, or solid phases; and multiple transformation processes. They also provide an explicit quantification of the characteristic soil penetration depth. We construct a compartment model using three and four soil layers to replicate with high reliability the flux and <span class="hlt">mass</span> distribution obtained from the exact analyticalmore » solution describing the transient dispersion, advection, and transformation of chemicals in soil with fixed properties and boundary conditions. Unlike the analytical solution, which requires fixed boundary conditions, the soil compartment algorithms can be dynamically linked to other compartments (<span class="hlt">air</span>, vegetation, ground water, surface water) in multimedia fate models. We demonstrate and evaluate the performance of the algorithms in a model with applications to benzene, benzo(a)pyrene, MTBE, TCDD, and tritium.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JASMS..24.1016Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JASMS..24.1016Z"><span>Rapid Screening for Potential Epitopes Reactive with a Polycolonal Antibody by Solution-Phase H/D <span class="hlt">Exchange</span> Monitored by FT-ICR <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Qian; Noble, Kyle A.; Mao, Yuan; Young, Nicolas L.; Sathe, Shridhar K.; Roux, Kenneth H.; Marshall, Alan G.</p> <p>2013-07-01</p> <p>The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D <span class="hlt">exchange</span> (HDX) coupled with Fourier transform ion cyclotron resonance <span class="hlt">mass</span> spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D <span class="hlt">exchange</span> upon pAb binding are identified as potential epitopes and mapped onto a homologous model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10466E..6FS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10466E..6FS"><span>Potential sources of the <span class="hlt">air</span> <span class="hlt">masses</span> leading to warm and cold anomalies in Moscow in summer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shukurov, K. A.; Semenov, V. A.</p> <p>2017-11-01</p> <p>For summer (June-July-August) days in 1949-2016, using the NOAA trajectory model HYSPLIT_4, the 5-day backward trajectories of the <span class="hlt">air</span> parcels (elementary <span class="hlt">air</span> particles) were calculated. Using the daily surface <span class="hlt">air</span> temperatures (SAT) in summer in Moscow in 1949-2016 and the results of the backward trajectories modeling by PSCF (potential source contribution function) and CWT (concentration weighted trajectories) methods the regions where the <span class="hlt">air</span> <span class="hlt">masses</span> most probably hit to before its arrive into the Moscow region at the days of 20%, 10%, 5% and 2% of the strongest positive and negative anomalies of SAT in summer in Moscow. For composites of days with SAT in summer in Moscow above 90th and below the 10th percentile of the distribution function of the SAT, the field of the anomaly of atmospheric pressure at sea level relative to 1981-2010 climatology and the field of average SAT in Eurasia north of 30° N are calculated. The peculiarities of the fields associated with the strong positive and negative anomalies of SAT in summer seasons in Moscow are identified. The fields of potential sources of <span class="hlt">air</span> parcels, mean <span class="hlt">air</span> temperature on the path of the movement of <span class="hlt">air</span> parcels and the average height of the backward trajectory for days with strong anomalies of SAT in summer in Moscow are compared. Possible atmospheric circulation drivers of the highest and lowest anomalies of SAT in winter in Moscow are found out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/4431','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/4431"><span>Enabling User Preferences Through Data <span class="hlt">Exchange</span></span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>1997-08-01</p> <p>This paper describes a process, via user- <span class="hlt">air</span> traffic management (ATM) data : <span class="hlt">exchange</span>, for enabling user preferences in an ATM-based system. User : preferences may be defined in terms of a four-dimensional (4D) user-preferred : trajectory, or a seri...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3113475','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3113475"><span>Differential hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry analysis of protein–ligand interactions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chalmers, Michael J; Busby, Scott A; Pascal, Bruce D; West, Graham M; Griffin, Patrick R</p> <p>2011-01-01</p> <p>Functional regulation of ligand-activated receptors is driven by alterations in the conformational dynamics of the protein upon ligand binding. Differential hydrogen/deuterium <span class="hlt">exchange</span> (HDX) coupled with <span class="hlt">mass</span> spectrometry has emerged as a rapid and sensitive approach for characterization of perturbations in conformational dynamics of proteins following ligand binding. While this technique is sensitive to detecting ligand interactions and alterations in receptor dynamics, it also can provide important mechanistic insights into ligand regulation. For example, HDX has been used to determine a novel mechanism of ligand activation of the nuclear receptor peroxisome proliferator activated receptor-γ, perform detailed analyses of binding modes of ligands within the ligand-binding pocket of two estrogen receptor isoforms, providing insight into selectivity, and helped classify different types of estrogen receptor-α ligands by correlating their pharmacology with the way they interact with the receptor based solely on hierarchical clustering of receptor HDX signatures. Beyond small-molecule–receptor interactions, this technique has also been applied to study protein–protein complexes, such as mapping antibody–antigen interactions. In this article, we summarize the current state of the differential HDX approaches and the future outlook. We summarize how HDX analysis of protein–ligand interactions has had an impact on biology and drug discovery. PMID:21329427</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29498268','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29498268"><span>Unequal <span class="hlt">Exchange</span> of <span class="hlt">Air</span> Pollution and Economic Benefits Embodied in China's Exports.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Wei; Wang, Feng; Hubacek, Klaus; Liu, Yu; Wang, Jinnan; Feng, Kuishuang; Jiang, Ling; Jiang, Hongqiang; Zhang, Bing; Bi, Jun</p> <p>2018-04-03</p> <p>As the world's factory, China has enjoyed huge economic benefits from international export but also suffered severe environmental consequences. Most studies investigating unequal environmental <span class="hlt">exchange</span> associated with trade took China as a homogeneous entity ignoring considerable inequality and outsourcing of pollution within China. This paper traces the regional mismatch of export-induced economic benefits and environmental costs along national supply chains by using the latest multiregional input-output model and emission inventory for 2012. The results indicate that approximately 56% of the national GDP induced by exports has been received by developed coastal regions, while about 72% of <span class="hlt">air</span> pollution embodied in national exports, measured as aggregated atmospheric pollutant equivalents (APE), has been mainly incurred by less developed central and western regions. For each yuan of export-induced GDP, developed regions only incurred 0.4-0.6 g APE emissions, whereas less developed regions from western or central China had to suffer 4-8 times the amount of emissions. This is due to poorer regions providing lower value added and higher emission-intensive inputs and having lower environmental standards and less efficient technologies. Our results may pave a way to mitigate the unequal relationship between developed and less developed regions from the perspective of environment-economy nexus.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25057757','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25057757"><span>International system of units traceable results of Hg <span class="hlt">mass</span> concentration at saturation in <span class="hlt">air</span> from a newly developed measurement procedure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Quétel, Christophe R; Zampella, Mariavittoria; Brown, Richard J C; Ent, Hugo; Horvat, Milena; Paredes, Eduardo; Tunc, Murat</p> <p>2014-08-05</p> <p>Data most commonly used at present to calibrate measurements of mercury vapor concentrations in <span class="hlt">air</span> come from a relationship known as the "Dumarey equation". It uses a fitting relationship to experimental results obtained nearly 30 years ago. The way these results relate to the international system of units (SI) is not known. This has caused difficulties for the specification and enforcement of limit values for mercury concentrations in <span class="hlt">air</span> and in emissions to <span class="hlt">air</span> as part of national or international legislation. Furthermore, there is a significant discrepancy (around 7% at room temperature) between the Dumarey data and data calculated from results of mercury vapor pressure measurements in the presence of only liquid mercury. As an attempt to solve some of these problems, a new measurement procedure is described for SI traceable results of gaseous Hg concentrations at saturation in milliliter samples of <span class="hlt">air</span>. The aim was to propose a scheme as immune as possible to analytical biases. It was based on isotope dilution (ID) in the liquid phase with the (202)Hg enriched certified reference material ERM-AE640 and measurements of the mercury isotope ratios in ID blends, subsequent to a cold vapor generation step, by inductively coupled plasma <span class="hlt">mass</span> spectrometry. The process developed involved a combination of interconnected valves and syringes operated by computer controlled pumps and ensured continuity under closed circuit conditions from the <span class="hlt">air</span> sampling stage onward. Quantitative trapping of the gaseous mercury in the liquid phase was achieved with 11.5 μM KMnO4 in 2% HNO3. <span class="hlt">Mass</span> concentrations at saturation found from five measurements under room temperature conditions were significantly higher (5.8% on average) than data calculated from the Dumarey equation, but in agreement (-1.2% lower on average) with data based on mercury vapor pressure measurement results. Relative expanded combined uncertainties were estimated following a model based approach. They ranged from 2</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750008008','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750008008"><span>Operational performance of a low cost, <span class="hlt">air</span> <span class="hlt">mass</span> 2 solar simulator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yass, K.; Curtis, H. B.</p> <p>1975-01-01</p> <p>Modifications and improvements on a low cost <span class="hlt">air</span> <span class="hlt">mass</span> 2 solar simulator are discussed. The performance characteristics of total irradiance, uniformity of irradiance, spectral distribution, and beam subtense angle are presented. The simulator consists of an array of tungsten halogen lamps hexagonally spaced in a plane. A corresponding array of plastic Fresnel lenses shapes the output beam such that the simulator irradiates a 1.2 m by 1.2 m area with uniform collimated irradiance. Details are given concerning individual lamp output measurements and placement of the lamps. Originally, only the direct component of solar irradiance was simulated. Since the diffuse component may affect the performance of some collectors, the capability to simulate it is being added. An approach to this diffuse addition is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120015618','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120015618"><span>Progress Toward a Global, EOS-Era Aerosol <span class="hlt">Air</span> <span class="hlt">Mass</span> Type Climatology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kahn, Ralph A.</p> <p>2012-01-01</p> <p>The MISR and MODIS instruments aboard the NASA Earth Observing System's Terra Satellite have been collecting data containing information about the state of Earth's atmosphere and surface for over eleven years. Data from these instruments have been used to develop a global, monthly climatology of aerosol amount that is widely used as a constraint on climate models, including those used for the 2007 IPCC assessment report. The next frontier in assessing aerosol radiative forcing of climate is aerosol type, and in particular, the absorption properties of major aerosol <span class="hlt">air</span> <span class="hlt">masses</span>. This presentation will focus on the prospects for constraining aerosol type globally, and the steps we are taking to apply a combination of satellite and suborbital data to this challenge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110008919','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110008919"><span>Microgravity condensing heat <span class="hlt">exchanger</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, Christopher M. (Inventor); Ma, Yonghui (Inventor); North, Andrew (Inventor); Weislogel, Mark M. (Inventor)</p> <p>2011-01-01</p> <p>A heat <span class="hlt">exchanger</span> having a plurality of heat <span class="hlt">exchanging</span> aluminum fins with hydrophilic condensing surfaces which are stacked and clamped between two cold plates. The cold plates are aligned radially along a plane extending through the axis of a cylindrical duct and hold the stacked and clamped portions of the heat <span class="hlt">exchanging</span> fins along the axis of the cylindrical duct. The fins extend outwardly from the clamped portions along approximately radial planes. The spacing between fins is symmetric about the cold plates, and are somewhat more closely spaced as the angle they make with the cold plates approaches 90.degree.. Passageways extend through the fins between vertex spaces which provide capillary storage and communicate with passageways formed in the stacked and clamped portions of the fins, which communicate with water drains connected to a pump externally to the duct. Water with no entrained <span class="hlt">air</span> is drawn from the capillary spaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770000092&hterms=Auxillary&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DAuxillary','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770000092&hterms=Auxillary&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DAuxillary"><span>Removing CO2 and moisture from <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tepper, E. H.</p> <p>1977-01-01</p> <p>Foamed-aluminum blocks act as passive heat <span class="hlt">exchanger</span> to improve efficiency. Improved closed-cycle atmospheric scrubber, level of carbon dioxide, and water vapor are reduced without affecting temperature of airstream. <span class="hlt">Exchangers</span> draw impurities from <span class="hlt">air</span> without additional heaters of auxillary equipment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120012821','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120012821"><span>Constraining Aerosol Optical Models Using Ground-Based, Collocated Particle Size and <span class="hlt">Mass</span> Measurements in Variable <span class="hlt">Air</span> <span class="hlt">Mass</span> Regimes During the 7-SEAS/Dongsha Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bell, Shaun W.; Hansell, Richard A.; Chow, Judith C.; Tsay, Si-Chee; Wang, Sheng-Hsiang; Ji, Qiang; Li, Can; Watson, John G.; Khlystov, Andrey</p> <p>2012-01-01</p> <p>During the spring of 2010, NASA Goddard's COMMIT ground-based mobile laboratory was stationed on Dongsha Island off the southwest coast of Taiwan, in preparation for the upcoming 2012 7-SEAS field campaign. The measurement period offered a unique opportunity for conducting detailed investigations of the optical properties of aerosols associated with different <span class="hlt">air</span> <span class="hlt">mass</span> regimes including background maritime and those contaminated by anthropogenic <span class="hlt">air</span> pollution and mineral dust. What appears to be the first time for this region, a shortwave optical closure experiment for both scattering and absorption was attempted over a 12-day period during which aerosols exhibited the most change. Constraints to the optical model included combined SMPS and APS number concentration data for a continuum of fine and coarse-mode particle sizes up to PM2.5. We also take advantage of an IMPROVE chemical sampler to help constrain aerosol composition and <span class="hlt">mass</span> partitioning of key elemental species including sea-salt, particulate organic matter, soil, non sea-salt sulphate, nitrate, and elemental carbon. Our results demonstrate that the observed aerosol scattering and absorption for these diverse <span class="hlt">air</span> <span class="hlt">masses</span> are reasonably captured by the model, where peak aerosol events and transitions between key aerosols types are evident. Signatures of heavy polluted aerosol composed mostly of ammonium and non sea-salt sulphate mixed with some dust with transitions to background sea-salt conditions are apparent in the absorption data, which is particularly reassuring owing to the large variability in the imaginary component of the refractive indices. Extinctive features at significantly smaller time scales than the one-day sample period of IMPROVE are more difficult to reproduce, as this requires further knowledge concerning the source apportionment of major chemical components in the model. Consistency between the measured and modeled optical parameters serves as an important link for advancing remote</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1210133Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1210133Z"><span><span class="hlt">Air</span>-sea fluxes of momentum and <span class="hlt">mass</span> in the presence of wind waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zülicke, Christoph</p> <p>2010-05-01</p> <p>An <span class="hlt">air</span>-sea interaction model (ASIM) is developed including the effect of wind waves on momentum and <span class="hlt">mass</span> transfer. This includes the derivation of profiles of dissipation rate, flow speed and concentration from a certain height to a certain depth. Simplified assumptions on the turbulent closure, skin - bulk matching and the spectral wave model allow for an analytic treatment. Particular emphasis was put on the inclusion of primary (gravity) waves and secondary (capillary-gravity) waves. The model was tuned to match wall-flow theory and data on wave height and slope. Growing waves reduce the <span class="hlt">air</span>-side turbulent stress and lead to an increasing drag coefficient. In the sea, breaking waves inject turbulent kinetic energy and accelerate the transfer. Cross-reference with data on wave-related momentum and energy flux, dissipation rate and transfer velocity was sufficient. The evaluation of ASIM allowed for the analytical calculation of bulk formulae for the wind-dependent gas transfer velocity including information on the <span class="hlt">air</span>-side momentum transfer (drag coefficient) and the sea-side gas transfer (Dalton number). The following regimes have been identified: the smooth waveless regime with a transfer velocity proportional to (wind) × (diffusion)2-3, the primary wave regime with a wind speed dependence proportional to (wind)1-4 × (diffusion)1-2-(waveage)1-4 and the secondary wave regime including a more-than-linear wind speed dependence like (wind)15-8 × (diffusion)1-2 × (waveage)5-8. These findings complete the current understanding of <span class="hlt">air</span>-sea interaction for medium winds between 2 and 20 m s^-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6497489-low-temperature-air-high-iaq-dry-climates','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6497489-low-temperature-air-high-iaq-dry-climates"><span>Low temperature <span class="hlt">air</span> with high IAQ for dry climates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Scofield, C.M.; Des Champs, N.H.</p> <p>1995-01-01</p> <p>This article describes how low temperature supply <span class="hlt">air</span> and <span class="hlt">air-to-air</span> heat <span class="hlt">exchangers</span> can furnish 100% outdoor <span class="hlt">air</span> with reduced peak energy demands. The use of low temperature supply <span class="hlt">air</span> systems in arid climates greatly simplifies the <span class="hlt">air</span>-conditioning design. Risks associated with moisture migration and sweating of duct and terminal equipment are reduced. Insulation and vapor barrier design requirements are not nearly as critical as they are in the humid, ambient conditions that exist in the eastern United States. The introduction of outdoor <span class="hlt">air</span> to meet ASHRAE Standard 62-1989 becomes far less taxing on the mechanical cooling equipment because of themore » lower enthalpy levels of the dry western climate. Energy costs to assure indoor <span class="hlt">air</span> quality (IAQ) are lower than for more tropical climates. In arid regions, maintaining acceptable indoor relative humidity (RH) levels becomes a major IAQ concern. For the western United States, coupling an <span class="hlt">air-to-air</span> heat <span class="hlt">exchanger</span> to direct (adiabatic) evaporative coolers can greatly reduce low temperature supply <span class="hlt">air</span> refrigeration energy requirements and winter humidification costs while ensuring proper ventilation.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24184550','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24184550"><span>Organochlorine pesticides in surface soils from obsolete pesticide dumping ground in Hyderabad City, Pakistan: contamination levels and their potential for <span class="hlt">air</span>-soil <span class="hlt">exchange</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alamdar, Ambreen; Syed, Jabir Hussain; Malik, Riffat Naseem; Katsoyiannis, Athanasios; Liu, Junwen; Li, Jun; Zhang, Gan; Jones, Kevin C</p> <p>2014-02-01</p> <p>This study was conducted to examine organochlorine pesticides (OCPs) contamination levels in the surface soil and <span class="hlt">air</span> samples together with <span class="hlt">air</span>-soil <span class="hlt">exchange</span> fluxes at an obsolete pesticide dumping ground and the associated areas from Hyderabad City, Pakistan. Among all the sampling sites, concentrations of OCPs in the soil and <span class="hlt">air</span> samples were found highest in obsolete pesticide dumping ground, whereas dominant contaminants were dichlorodiphenyltrichloroethane (DDTs) (soil: 77-212,200 ng g(-1); <span class="hlt">air</span>: 90,700 pg m(-3)) and hexachlorocyclohexane (HCHs) (soil: 43-4,090 ng g(-1); <span class="hlt">air</span>: 97,400 pg m(-3)) followed by chlordane, heptachlor and hexachlorobenzene (HCB). OCPs diagnostic indicative ratios reflect historical use as well as fresh input in the study area. Moreover, the <span class="hlt">air</span> and soil fugacity ratios (0.9-1.0) at the dumping ground reflecting a tendency towards net volatilization of OCPs, while at the other sampling sites, the fugacity ratios indicate in some cases deposition and in other cases volatilization. Elevated concentrations of DDTs and HCHs at pesticide dumping ground and its surroundings pose potential exposure risk to biological organisms, to the safety of agricultural products and to the human health. Our study thus emphasizes the need of spatio-temporal monitoring of OCPs at local and regional scale to assess and remediate the future adverse implications. © 2013.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5783867-effect-residential-air-air-heat-moisture-exchangers-indoor-humidity','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5783867-effect-residential-air-air-heat-moisture-exchangers-indoor-humidity"><span>Effect of residential <span class="hlt">air-to-air</span> heat and moisture <span class="hlt">exchangers</span> on indoor humidity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Barringer, C.G.; McGugan, C.A.</p> <p>1989-01-01</p> <p>A project was undertaken to develop guidelines for the selection of residential heat and moisture recovery ventilation systems (HRVs) in order to maintain an acceptable indoor humidity for various climatic conditions. These guidelines were developed from reviews on ventilation requirements, HRV performance specifications, and from computer modeling. Space conditions within three house/occupancy models for several types of HRV were simulated for three climatic conditions (Lake Charles, LA; Seattle, WA; and Winnipeg, MB) in order to determine the impact of the HRVs on indoor relative humidity and space-conditioning loads. Results show that when reduction of cooling cost is the main consideration,more » <span class="hlt">exchangers</span> with moisture recovery are preferable to sensible HRVs. For reduction of heating costs, moisture recovery should be done for ventilation rates greater than about 15 L/s and average winter temperatures less than about (minus) 10{degrees}C if internal moisture generation rates are low. For houses with higher ventilation rates and colder average winter temperatures, <span class="hlt">exchangers</span> with moisture recovery should be used.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JASMS..28..795H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JASMS..28..795H"><span>Characterization of Aggregation Propensity of a Human Fc-Fusion Protein Therapeutic by Hydrogen/Deuterium <span class="hlt">Exchange</span> <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Richard Y.-C.; Iacob, Roxana E.; Krystek, Stanley R.; Jin, Mi; Wei, Hui; Tao, Li; Das, Tapan K.; Tymiak, Adrienne A.; Engen, John R.; Chen, Guodong</p> <p>2017-05-01</p> <p>Aggregation of protein therapeutics has long been a concern across different stages of manufacturing processes in the biopharmaceutical industry. It is often indicative of aberrant protein therapeutic higher-order structure. In this study, the aggregation propensity of a human Fc-fusion protein therapeutic was characterized. Hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) was applied to examine the conformational dynamics of dimers collected from a bioreactor. HDX-MS data combined with spatial aggregation propensity calculations revealed a potential aggregation interface in the Fc domain. This study provides a general strategy for the characterization of the aggregation propensity of Fc-fusion proteins at the molecular level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A41A0045W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A41A0045W"><span>Fullerene Soot in Eastern China <span class="hlt">Air</span>: Results from Soot Particle-Aerosol <span class="hlt">Mass</span> Spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, J.; Ge, X.; Chen, M.; Zhang, Q.; Yu, H.; Sun, Y.; Worsnop, D. R.; Collier, S.</p> <p>2015-12-01</p> <p>In this work, we present for the first time, the observation and quantification of fullerenes in ambient airborne particulate using an Aerodyne Soot Particle - Aerosol <span class="hlt">Mass</span> Spectrometer (SP-AMS) deployed during 2015 winter in suburban Nanjing, a megacity in eastern China. The laser desorption and electron impact ionization techniques employed by the SP-AMS allow us to differentiate various fullerenes from other aerosol components. <span class="hlt">Mass</span> spectrum of the identified fullerene soot is consisted by a series of high molecular weight carbon clusters (up to m/z of 2000 in this study), almost identical to the spectral features of commercially available fullerene soot, both with C70 and C60 clusters as the first and second most abundant species. This type of soot was observed throughout the entire study period, with an average <span class="hlt">mass</span> loading of 0.18 μg/m3, accounting for 6.4% of the black carbon <span class="hlt">mass</span>, 1.2% of the total organic <span class="hlt">mass</span>. Temporal variation and diurnal pattern of fullerene soot are overall similar to those of black carbon, but are clearly different in some periods. Combining the positive matrix factorization, back-trajectory and analyses of the meteorological parameters, we identified the petrochemical industrial plants situating upwind from the sampling site, as the major source of fullerene soot. In this regard, our findings imply the ubiquitous presence of fullerene soot in ambient <span class="hlt">air</span> of industry-influenced area, especially the oil and gas production regions. This study also offers new insights into the characterization of fullerenes from other environmental samples via the advanced SP-AMS technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=65360&keyword=day+AND+night&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=65360&keyword=day+AND+night&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>MONITORING CYCLICAL <span class="hlt">AIR</span>-WATER ELEMENTAL MERCURY <span class="hlt">EXCHANGE</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Previous experimental work has demonstrated that elemental mercury evasion from natural water displays a diel cycle; evasion rates during the day can be two to three times evasion rates observed at night. A study with polychlorinated biphenyls (PCBS) found that diurnal PCB <span class="hlt">air</span>/wa...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AtmEn..92....9B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AtmEn..92....9B"><span>Influence of trans-boundary biomass burning impacted <span class="hlt">air</span> <span class="hlt">masses</span> on submicron particle number concentrations and size distributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Betha, Raghu; Zhang, Zhe; Balasubramanian, Rajasekhar</p> <p>2014-08-01</p> <p>Submicron particle number concentration (PNC) and particle size distribution (PSD) in the size range of 5.6-560 nm were investigated in Singapore from 27 June 2009 through 6 September 2009. Slightly hazy conditions lasted in Singapore from 6 to 10 August. Backward <span class="hlt">air</span> trajectories indicated that the haze was due to the transport of biomass burning impacted <span class="hlt">air</span> <span class="hlt">masses</span> originating from wild forest and peat fires in Sumatra, Indonesia. Three distinct peaks in the morning (08:00-10:00), afternoon (13:00-15:00) and evening (16:00-20:00) were observed on a typical normal day. However, during the haze period no distinct morning and afternoon peaks were observed and the PNC (39,775 ± 3741 cm-3) increased by 1.5 times when compared to that during non-haze periods (26,462 ± 6017). The morning and afternoon peaks on the normal day were associated with the local rush hour traffic while the afternoon peak was induced by new particle formation (NPF). Diurnal profiles of PNCs and PSDs showed that primary particle peak diameters were large during the haze (60 nm) period when compared to that during the non-haze period (45.3 nm). NPF events observed in the afternoon period on normal days were suppressed during the haze periods due to heavy particle loading in atmosphere caused by biomass burning impacted <span class="hlt">air</span> <span class="hlt">masses</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JASMS..28..486H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JASMS..28..486H"><span>Determination of Equine Cytochrome c Backbone Amide Hydrogen/Deuterium <span class="hlt">Exchange</span> Rates by <span class="hlt">Mass</span> Spectrometry Using a Wider Time Window and Isotope Envelope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamuro, Yoshitomo</p> <p>2017-03-01</p> <p>A new strategy to analyze amide hydrogen/deuterium <span class="hlt">exchange</span> <span class="hlt">mass</span> spectrometry (HDX-MS) data is proposed, utilizing a wider time window and isotope envelope analysis of each peptide. While most current scientific reports present HDX-MS data as a set of time-dependent deuteration levels of peptides, the ideal HDX-MS data presentation is a complete set of backbone amide hydrogen <span class="hlt">exchange</span> rates. The ideal data set can provide single amide resolution, coverage of all <span class="hlt">exchange</span> events, and the open/close ratio of each amide hydrogen in EX2 mechanism. Toward this goal, a typical HDX-MS protocol was modified in two aspects: measurement of a wider time window in HDX-MS experiments and deconvolution of isotope envelope of each peptide. Measurement of a wider time window enabled the observation of deuterium incorporation of most backbone amide hydrogens. Analysis of the isotope envelope instead of centroid value provides the deuterium distribution instead of the sum of deuteration levels in each peptide. A one-step, global-fitting algorithm optimized <span class="hlt">exchange</span> rate and deuterium retention during the analysis of each amide hydrogen by fitting the deuterated isotope envelopes at all time points of all peptides in a region. Application of this strategy to cytochrome c yielded 97 out of 100 amide hydrogen <span class="hlt">exchange</span> rates. A set of <span class="hlt">exchange</span> rates determined by this approach is more appropriate for a patent or regulatory filing of a biopharmaceutical than a set of peptide deuteration levels obtained by a typical protocol. A wider time window of this method also eliminates false negatives in protein-ligand binding site identification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Nonli..31.3460E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Nonli..31.3460E"><span>Mathematical theory of <span class="hlt">exchange</span>-driven growth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Esenturk, Emre</p> <p>2018-07-01</p> <p><span class="hlt">Exchange</span>-driven growth is a process in which pairs of clusters interact by <span class="hlt">exchanging</span> single unit of <span class="hlt">mass</span> at a time. The rate of <span class="hlt">exchange</span> is given by an interaction kernel which depends on the <span class="hlt">masses</span> of the two interacting clusters. In this paper we establish the fundamental mathematical properties of the mean field rate equations of this process for the first time. We find two different classes of behavior depending on whether is symmetric or not. For the non-symmetric case, we prove global existence and uniqueness of solutions for kernels satisfying . This result is optimal in the sense that we show for a large class of initial conditions and kernels satisfying the solutions cannot exist. On the other hand, for symmetric kernels, we prove global existence of solutions for ( while existence is lost for ( In the intermediate regime we can only show local existence. We conjecture that the intermediate regime exhibits finite-time gelation in accordance with the heuristic results obtained for particular kernels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26810432','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26810432"><span>Tuning a High Transmission Ion Guide to Prevent Gas-Phase Proton <span class="hlt">Exchange</span> During H/D <span class="hlt">Exchange</span> MS Analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guttman, Miklos; Wales, Thomas E; Whittington, Dale; Engen, John R; Brown, Jeffery M; Lee, Kelly K</p> <p>2016-04-01</p> <p>Hydrogen/deuterium <span class="hlt">exchange</span> (HDX) <span class="hlt">mass</span> spectrometry (MS) for protein structural analysis has been adopted for many purposes, including biopharmaceutical development. One of the benefits of examining amide proton <span class="hlt">exchange</span> by <span class="hlt">mass</span> spectrometry is that it can readily resolve different <span class="hlt">exchange</span> regimes, as evidenced by either binomial or bimodal isotope patterns. By careful analysis of the isotope pattern during <span class="hlt">exchange</span>, more insight can be obtained on protein behavior in solution. However, one must be sure that any observed bimodal isotope patterns are not artifacts of analysis and are reflective of the true behavior in solution. Sample carryover and certain stationary phases are known as potential sources of bimodal artifacts. Here, we describe an additional undocumented source of deuterium loss resulting in artificial bimodal patterns for certain highly charged peptides. We demonstrate that this phenomenon is predominantly due to gas-phase proton <span class="hlt">exchange</span> between peptides and bulk solvent within the initial stages of high-transmission conjoined ion guides. Minor adjustments of the ion guide settings, as reported here, eliminate the phenomenon without sacrificing signal intensity. Such gas-phase deuterium loss should be appreciated for all HDX-MS studies using such ion optics, even for routine studies not focused on interpreting bimodal spectra. Graphical Abstract ᅟ.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ACP....1113181L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACP....1113181L"><span>Reactive nitrogen, ozone and ozone production in the Arctic troposphere and the impact of stratosphere-troposphere <span class="hlt">exchange</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, Q.; Rodriguez, J. M.; Douglass, A. R.; Crawford, J. H.; Olson, J. R.; Apel, E.; Bian, H.; Blake, D. R.; Brune, W.; Chin, M.; Colarco, P. R.; da Silva, A.; Diskin, G. S.; Duncan, B. N.; Huey, L. G.; Knapp, D. J.; Montzka, D. D.; Nielsen, J. E.; Pawson, S.; Riemer, D. D.; Weinheimer, A. J.; Wisthaler, A.</p> <p>2011-12-01</p> <p>We use aircraft observations obtained during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission to examine the distributions and source attributions of O3 and NOy in the Arctic and sub-Arctic region. Using a number of marker tracers, we distinguish various <span class="hlt">air</span> <span class="hlt">masses</span> from the background troposphere and examine their contributions to NOx, O3, and O3 production in the Arctic troposphere. The background Arctic troposphere has a mean O3 of ~60 ppbv and NOx of ~25 pptv throughout spring and summer with CO decreasing from ~145 ppbv in spring to ~100 ppbv in summer. These observed mixing ratios are not notably different from the values measured during the 1988 ABLE-3A and the 2002 TOPSE field campaigns despite the significant changes in emissions and stratospheric ozone layer in the past two decades that influence Arctic tropospheric composition. <span class="hlt">Air</span> <span class="hlt">masses</span> associated with stratosphere-troposphere <span class="hlt">exchange</span> are present throughout the mid and upper troposphere during spring and summer. These <span class="hlt">air</span> <span class="hlt">masses</span>, with mean O3 concentrations of 140-160 ppbv, are significant direct sources of O3 in the Arctic troposphere. In addition, <span class="hlt">air</span> of stratospheric origin displays net O3 formation in the Arctic due to its sustainable, high NOx (75 pptv in spring and 110 pptv in summer) and NOy (~800 pptv in spring and ~1100 pptv in summer). The <span class="hlt">air</span> <span class="hlt">masses</span> influenced by the stratosphere sampled during ARCTAS-B also show conversion of HNO3 to PAN. This active production of PAN is the result of increased degradation of ethane in the stratosphere-troposphere mixed <span class="hlt">air</span> <span class="hlt">mass</span> to form CH3CHO, followed by subsequent formation of PAN under high NOx conditions. These findings imply that an adequate representation of stratospheric NOy input, in addition to stratospheric O3 influx, is essential to accurately simulate tropospheric Arctic O3, NOx and PAN in chemistry transport models. Plumes influenced by recent anthropogenic and biomass burning emissions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11613284','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11613284"><span>[Medical <span class="hlt">exchanges</span> among China and Asiana countries].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, H</p> <p>1996-01-01</p> <p>Among the issues of medical <span class="hlt">exchanges</span>, medicaments are more often encountered than medical issues, based on ancient Chinese literatures, early in the Han-Jin Dynasties, Thailand, Malaysia, Indonesia, and Brunei had <span class="hlt">exchanges</span> with China, also in Sui-Tang Dynasties. In the Song-Yuan Dynasties, ancient Singapore and the Philippines also incorporated in <span class="hlt">exchanges</span> of medicament and goods. In the Ming-Qing dynasties, these 6 Asian countries had even more close contact with China, especially in trades and medical <span class="hlt">exchanges</span> among the <span class="hlt">masses</span>, carried out in a large scale thus, promoting the advent and development of TCM in Asiana Regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920012283','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920012283"><span>Cryogenic hydrogen-induced <span class="hlt">air</span>-liquefaction technologies for combined-cycle propulsion applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Escher, William J. D.</p> <p>1992-01-01</p> <p>Given here is a technical assessment of the realization of cryogenic hydrogen induced <span class="hlt">air</span> liquefaction technologies in a prospective onboard aerospace vehicle process setting. The technical findings related to the status of <span class="hlt">air</span> liquefaction technologies are reviewed. Compact lightweight cryogenic heat <span class="hlt">exchangers</span>, heat <span class="hlt">exchanger</span> atmospheric constituent fouling alleviation measures, para/ortho-hydrogen shift-conversion catalysts, cryogenic <span class="hlt">air</span> compressors and liquid <span class="hlt">air</span> pumps, hydrogen recycling using slush hydrogen as a heat sink, liquid hydrogen/liquid <span class="hlt">air</span> rocket-type combustion devices, and technically related engine concepts are discussed. Much of the LACE work is related to aerospaceplane propulsion concepts that were developed in the 1960's. Emphasis is placed on the Liquid <span class="hlt">Air</span> Cycle Engine (LACE).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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