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Sample records for aerosol flow system

  1. A New Aerosol Flow System for Photochemical and Thermal Studies of Tropospheric Aerosols

    SciTech Connect

    Ezell, Michael J.; Johnson, Stanley N.; Yu, Yong; Perraud, Veronique; Bruns, Emily; Alexander, M. L.; Zelenyuk, Alla; Dabdub, Donald; Finlayson-Pitts, Barbara J.

    2010-05-01

    For studying the formation and photochemical/thermal reactions of aerosols relevant to the troposphere, a unique, high-volume, slow-flow, stainless steel aerosol flow system equipped with 5 UV lamps has been constructed and characterized experimentally. The total flow system length 6 is 8.5 m and includes a 1.2 m section used for mixing, a 6.1 m reaction section and a 1.2 m 7 transition cone at the end. The 45.7 cm diameter results in a smaller surface to volume ratio than is found in many other flow systems and thus reduces the potential contribution from wall reactions. The latter are also reduced by frequent cleaning of the flow tube walls which is made feasible by the ease of disassembly. The flow tube is equipped with ultraviolet lamps for photolysis. This flow system allows continuous sampling under stable conditions, thus increasing the amount of sample available for analysis and permitting a wide variety of analytical techniques to be applied simultaneously. The residence time is of the order of an hour, and sampling ports located along the length of the flow tube allow for time-resolved measurements of aerosol and gas-phase products. The system was characterized using both an inert gas (CO2) and particles (atomized NaNO3). Instruments interfaced directly to this flow system include a NOx analyzer, an ozone analyzer, relative humidity and temperature probes, a scanning mobility particle sizer spectrometer, an aerodynamic particle sizer spectrometer, a gas chromatograph-mass spectrometer, an integrating nephelometer, and a Fourier transform infrared spectrophotometer equipped with a long path (64 m) cell. Particles collected with impactors and filters at the various sampling ports can be analyzed subsequently by a variety of techniques. Formation of secondary organic aerosol from α-pinene reactions (NOx photooxidation and ozonolysis) are used to demonstrate the capabilities of this new system.

  2. Construction, Modeling and Testing of a Low-Flow, Large-Diameter Aerosol Flow System for the Study of the Formation and Reactions of Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Ezell, M. J.; Johnson, S. N.; Yu, Y.; Pokkunuri, P.; Perraud, V.; Bruns, E.; Alexander, M.; Zelenyuk, A.; Dabdub, D.; Finlayson-Pitts, B. J.

    2008-12-01

    A unique, high-volume, low-flow, stainless steel aerosol flow system for the study of the formation and reactions of aerosols relevant to the troposphere has been constructed, modeled and experimentally tested. The total flow tube length is 7.3 m which includes a 1.2 m section used for mixing. The flow tube is equipped with ultraviolet lamps for photolysis. The diameter of 0.45 m results in a smaller surface to volume ratio than is found in many other flow systems and reduces the contribution of wall reactions. The latter is also reduced by frequent cleaning of the flow tube walls which is feasible due to the ease of disassembly of the flow tube. Flow systems present a major advantage over chamber studies in that continuous sampling under stable conditions over long periods of time is possible, increasing the amount of sample available for analysis and permitting a wide variety of analytical techniques to be applied simultaneously. In this system, the large volume (1000 L) and low flow speed (2 cm/minute) result in a residence time of nearly an hour; and equally spaced sampling ports allow for time-resolved measurements of aerosol and gas-phase products. The central features of this system have been modeled using computational fluid dynamics software and experimentally probed using inert gases and aerosols. Instrumentation attached directly to this flow system includes a NOx analyzer, an ozone analyzer, relative humidity and temperature probes, a scanning mobility particle sizer (SMPS) spectrometer, an aerodynamic particle sizer (APS) spectrometer, GC-MS, integrating nephelometer, and FTIR. Particles are collected using impactors and filters, and analyzed by a variety of techniques including FTIR, electrospray ionization mass spectrometry (ESI-MS), atmospheric pressure chemical ionization mass spectrometry (APCI-MS), GC-MS, HPLC-UV and HPLC-MS. In addition, for selected studies, an aerosol mass spectrometer (AMS), a single particle mass spectrometer (SPLAT II) and

  3. Pressure-flow reducer for aerosol focusing devices

    DOEpatents

    Gard, Eric; Riot, Vincent; Coffee, Keith; Woods, Bruce; Tobias, Herbert; Birch, Jim; Weisgraber, Todd

    2008-04-22

    A pressure-flow reducer, and an aerosol focusing system incorporating such a pressure-flow reducer, for performing high-flow, atmosphere-pressure sampling while delivering a tightly focused particle beam in vacuum via an aerodynamic focusing lens stack. The pressure-flow reducer has an inlet nozzle for adjusting the sampling flow rate, a pressure-flow reduction region with a skimmer and pumping ports for reducing the pressure and flow to enable interfacing with low pressure, low flow aerosol focusing devices, and a relaxation chamber for slowing or stopping aerosol particles. In this manner, the pressure-flow reducer decouples pressure from flow, and enables aerosol sampling at atmospheric pressure and at rates greater than 1 liter per minute.

  4. Inter-comparison of laboratory smog chamber and flow reactor systems on organic aerosol yield and composition

    NASA Astrophysics Data System (ADS)

    Bruns, E. A.; El Haddad, I.; Keller, A.; Klein, F.; Kumar, N. K.; Pieber, S. M.; Corbin, J. C.; Slowik, J. G.; Brune, W. H.; Baltensperger, U.; Prévôt, A. S. H.

    2015-01-01

    A variety of tools are used to simulate atmospheric aging, including smog chambers and flow reactors. Traditional, large-scale smog chambers age emissions over the course of hours to days, whereas flow reactors rapidly age emissions using high oxidant concentrations to reach higher degrees of oxygenation than typically attained in smog chamber experiments. The atmospheric relevance of the products generated under such rapid oxidation warrants further study. However, no previously published studies have compared the yields and chemical composition of products generated in flow reactors and smog chambers from the same starting mixture. The yields and composition of the organic aerosol formed from the photo-oxidation of α-pinene and of wood combustion emissions were determined using aerosol mass spectrometry in a smog chamber (SC) and two flow reactors: a potential aerosol mass reactor (PAM) and a micro-smog chamber (MSC). Reactants were sampled from the SC and aged in the MSC and PAM using a range of hydroxyl radical (OH) concentrations and then photo-chemically aged in the SC. The maximum yields/emission factors and the chemical composition of the products in both the α-pinene and wood combustion systems determined with the PAM and SC agreed reasonably well. High OH exposures have been shown previously to lower yields by breaking carbon-carbon bonds and forming higher volatility species, which reside largely in the gas phase, however, fragmentation in the PAM was not observed. The yields determined using the PAM for the α-pinene system were slightly lower than in the SC, possibly from increased wall losses of gas-phase species due to the higher surface area to volume ratios in the PAM, even when offset with better isolation of the sampled flow from the walls. The α-pinene SOA results for the MSC were not directly comparable, as particles were smaller than the optimal AMS transmission range. For the wood combustion system, emission factors measured by the MSC

  5. Inter-comparison of laboratory smog chamber and flow reactor systems on organic aerosol yield and composition

    NASA Astrophysics Data System (ADS)

    Bruns, E. A.; El Haddad, I.; Keller, A.; Klein, F.; Kumar, N. K.; Pieber, S. M.; Corbin, J. C.; Slowik, J. G.; Brune, W. H.; Baltensperger, U.; Prévôt, A. S. H.

    2015-06-01

    A variety of tools are used to simulate atmospheric aging, including smog chambers and flow reactors. Traditional, large-scale smog chambers age emissions over the course of hours to days, whereas flow reactors rapidly age emissions using high oxidant concentrations to reach higher degrees of oxygenation than typically attained in smog chamber experiments. The atmospheric relevance of the products generated under such rapid oxidation warrants further study. However, no previously published studies have compared the yields and chemical composition of products generated in flow reactors and smog chambers from the same starting mixture. The yields and composition of the organic aerosol formed from the photo-oxidation of α-pinene and of wood-combustion emissions in a smog chamber (SC) and two flow reactors: a potential aerosol mass reactor (PAM) and a micro-smog chamber (MSC), were determined using aerosol mass spectrometry. Reactants were sampled from the SC and aged in the MSC and the PAM using a range of hydroxyl radical (OH) concentrations and then photo-chemically aged in the SC. The chemical composition, as well as the maximum yields and emission factors, of the products in both the α-pinene and wood-combustion systems determined with the PAM and the SC agreed reasonably well. High OH exposures have been shown previously to lower yields by breaking carbon-carbon bonds and forming higher volatility species, which reside largely in the gas phase; however, fragmentation in the PAM was not observed. The yields determined using the PAM for the α-pinene system were slightly lower than in the SC, possibly from increased wall losses of gas phase species due to the higher surface area to volume ratios in the PAM, even when offset with better isolation of the sampled flow from the walls. The α-pinene SOA results for the MSC were not directly comparable, as particles were smaller than the optimal AMS transmission range. The higher supersaturation in the flow reactors

  6. Modeling of Aerosols in Post-Combustor Flow Path and Sampling System

    NASA Technical Reports Server (NTRS)

    Wey, Thomas; Liu, Nan-Suey

    2006-01-01

    The development and application of a multi-dimensional capability for modeling and simulation of aviation-sourced particle emissions and their precursors are elucidated. Current focus is on the role of the flow and thermal environments. The cases investigated include a film cooled turbine blade, the first-stage of a high-pressure turbine, the sampling probes, the sampling lines, and a pressure reduction chamber.

  7. Aerosol sampling system

    DOEpatents

    Masquelier, Donald A.

    2004-02-10

    A system for sampling air and collecting particulate of a predetermined particle size range. A low pass section has an opening of a preselected size for gathering the air but excluding particles larger than the sample particles. An impactor section is connected to the low pass section and separates the air flow into a bypass air flow that does not contain the sample particles and a product air flow that does contain the sample particles. A wetted-wall cyclone collector, connected to the impactor section, receives the product air flow and traps the sample particles in a liquid.

  8. Aerosol Observing System (AOS) Handbook

    SciTech Connect

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  9. Radiological/biological/aerosol removal system

    DOEpatents

    Haslam, Jeffery J

    2015-03-17

    An air filter replacement system for existing buildings, vehicles, arenas, and other enclosed airspaces includes a replacement air filter for replacing a standard air filter. The replacement air filter has dimensions and air flow specifications that allow it to replace the standard air filter. The replacement air filter includes a filter material that removes radiological or biological or aerosol particles.

  10. Chemical aerosol flow synthesis of semiconductor nanoparticles.

    PubMed

    Didenko, Yuri T; Suslick, Kenneth S

    2005-09-01

    Nanometer-sized semiconductor particles (quantum dots) have been the subject of intense research during the past decade owing to their novel electronic, catalytic, and optical properties. Fundamental properties of these nanoparticles (1-20 nm diameter) can be systematically changed simply by controlling the size of the crystals while holding their chemical composition constant. We describe here a new methodology for the continuous production of fluorescent CdS, CdSe, and CdTe nanoparticles using ultrasonically generated aerosols of high boiling point solvents. Each submicron droplet serves as a separate nanoscale chemical reactor, with reactions proceeding as the liquid droplets (which hold both reactants and surface stabilizers) are heated in a gas stream. The method is inexpensive, scalable, and allows for the synthesis of high quality nanocrystals. This chemical aerosol flow synthesis (CAFS) can be extended to the synthesis of nanostructured metals, oxides, and other materials. PMID:16131177

  11. Multistage pH-responsive mucoadhesive nanocarriers prepared by aerosol flow reactor technology: A controlled dual protein-drug delivery system.

    PubMed

    Shrestha, Neha; Shahbazi, Mohammad-Ali; Araújo, Francisca; Mäkilä, Ermei; Raula, Janne; Kauppinen, Esko I; Salonen, Jarno; Sarmento, Bruno; Hirvonen, Jouni; Santos, Hélder A

    2015-11-01

    Nanotechnology based drug delivery systems are anticipated to overcome the persistent challenges in oral protein and peptide administration, and lead to the development of long awaited non-invasive therapies. Herein, an advanced single-step aerosol flow reactor based technology was used to develop a multifunctional site specific dual protein-drug delivery nanosystem. For this purpose, mucoadhesive porous silicon (PSi) nanoparticles encapsulated into a pH-responsive polymeric nanomatrix was developed for advanced oral type 2 diabetes mellitus therapy with an antidiabetic peptide, glucagon like peptide-1 (GLP-1), and the enzyme inhibitor, dipeptidyl peptidase-4 (DPP4). Chitosan surface modification inherited the mucoadhesiveness to the nanosystem which led to enhanced cellular interactions and increased cellular compatibility. An advanced aerosol flow reactor technology was used to encapsulate the chitosan modified nanoparticles into an enteric polymeric nanomatrix. The pH-sensitive polymeric matrix simultaneously prevented the gastric degradation of the encapsulated peptide and also preserved the mucoadhesive functionality of the chitosan-modified PSi nanoparticles in the harsh stomach environment. The multidrug loaded nanosystem showed augmented intestinal permeability of GLP-1, evaluated in an in vitro cell-based intestinal epithelium model, attributed to the permeation enhancer effect of chitosan and inhibition of GLP-1 degradation by the DPP4 inhibitor. The applied technology resulted in the development of a dual-drug delivery nanosystem that synergizes the antidiabetic effect of the loaded peptide and the enzyme inhibitor, thereby indicating high clinical potential of the system and preparation technique. PMID:26253804

  12. A System to Create Stable Nanoparticle Aerosols from Nanopowders.

    PubMed

    Ding, Yaobo; Riediker, Michael

    2016-01-01

    Nanoparticle aerosols released from nanopowders in workplaces are associated with human exposure and health risks. We developed a novel system, requiring minimal amounts of test materials (min. 200 mg), for studying powder aerosolization behavior and aerosol properties. The aerosolization procedure follows the concept of the fluidized-bed process, but occurs in the modified volume of a V-shaped aerosol generator. The airborne particle number concentration is adjustable by controlling the air flow rate. The system supplied stable aerosol generation rates and particle size distributions over long periods (0.5-2 hr and possibly longer), which are important, for example, to study aerosol behavior, but also for toxicological studies. Strict adherence to the operating procedures during the aerosolization experiments ensures the generation of reproducible test results. The critical steps in the standard protocol are the preparation of the material and setup, and the aerosolization operations themselves. The system can be used for experiments requiring stable aerosol concentrations and may also be an alternative method for testing dustiness. The controlled aerosolization made possible with this setup occurs using energy inputs (may be characterized by aerosolization air velocity) that are within the ranges commonly found in occupational environments where nanomaterial powders are handled. This setup and its operating protocol are thus helpful for human exposure and risk assessment. PMID:27501179

  13. Aerosol deposition in bends with turbulent flow

    SciTech Connect

    McFarland, A.R.; Gong, H.; Wente, W.B.

    1997-08-01

    The losses of aerosol particles in bends were determined numerically for a broad range of design and operational conditions. Experimental data were used to check the validity of the numerical model, where the latter employs a commercially available computational fluid dynamics code for characterizing the fluid flow field and Lagrangian particle tracking technique for characterizing aerosol losses. Physical experiments have been conducted to examine the effect of curvature ratio and distortion of the cross section of bends. If it curvature ratio ({delta} = R/a) is greater than about 4, it has little effect on deposition, which is in contrast with the recommendation given in ANSI N13.1-1969 for a minimum curvature ratio of 10. Also, experimental results show that if the tube cross section is flattened by 25% or less, the flattening also has little effect on deposition. Results of numerical tests have been used to develop a correlation of aerosol penetration through a bend as a function of Stokes number (Stk), curvature ratio ({delta}) and the bend angle ({theta}). 17 refs., 10 figs., 2 tabs.

  14. Aerosol Climate Interactions in Climate System Models

    NASA Astrophysics Data System (ADS)

    Kiehl, J. T.

    2002-12-01

    Aerosols are widely recognized as an important process in Earth's climate system. Observations over the past decade have improved our understanding of the physical and chemical properties of aerosols. Recently, field observations have highlighted the pervasiveness of absorbing aerosols in the atmosphere. These aerosols are of particular interest, since they alter the vertical distribution of shortwave radiative heating between the surface and atmosphere. Given this increased knowledge of aerosols from various field programs, interest is focusing on how to integrate this understanding into global climate models. These types of models provide the best tool available to comprehensively study the potential effects of aerosols on Earth's climate system. Results from climate system model simulations that include aerosol effects will be presented to illustrate key aerosol climate interactions. These simulations employ idealized and realistic distributions of absorbing aerosols. The idealized aerosol simulations provide insight into the role of aerosol shortwave absorption on the global hydrologic cycle. The realistic aerosol distributions provide insight into the local response of aerosol forcing in the Indian subcontinent region. Emphasis from these simulations will be on the hydrologic cycle, since water availability is of emerging global environmental concern. This presentation will also consider what more is needed to significantly improve our ability to model aerosol processes in climate system models. Uncertainty in aerosol climate interactions remains a major source of uncertainty in our ability to project future climate change. Focus will be on interactions between aerosols and various physical, chemical and biogeochemical aspects of the Earth system.

  15. Airborne Atmospheric Aerosol Measurement System

    NASA Astrophysics Data System (ADS)

    Ahn, K.; Park, Y.; Eun, H.; Lee, H.

    2015-12-01

    It is important to understand the atmospheric aerosols compositions and size distributions since they greatly affect the environment and human health. Particles in the convection layer have been a great concern in global climate changes. To understand these characteristics satellite, aircraft, and radio sonde measurement methods have usually been used. An aircraft aerosol sampling using a filter and/or impactor was the method commonly used (Jay, 2003). However, the flight speed particle sampling had some technical limitations (Hermann, 2001). Moreover, the flight legal limit, altitude, prohibited airspace, flight time, and cost was another demerit. To overcome some of these restrictions, Tethered Balloon Package System (T.B.P.S.) and Recoverable Sonde System(R.S.S.) were developed with a very light optical particle counter (OPC), impactor, and condensation particle counter (CPC). Not only does it collect and measure atmospheric aerosols depending on altitudes, but it also monitors the atmospheric conditions, temperature, humidity, wind velocity, pressure, GPS data, during the measurement (Eun, 2013). In this research, atmospheric aerosol measurement using T.B.P.S. in Ansan area is performed and the measurement results will be presented. The system can also be mounted to an unmanned aerial vehicle (UAV) and create an aerial particle concentration map. Finally, we will present measurement data using Tethered Balloon Package System (T.B.P.S.) and R.S.S (Recoverable Sonde System).

  16. Discrete-element modeling of particulate aerosol flows

    NASA Astrophysics Data System (ADS)

    Marshall, J. S.

    2009-03-01

    A multiple-time step computational approach is presented for efficient discrete-element modeling of aerosol flows containing adhesive solid particles. Adhesive aerosol particulates are found in numerous dust and smoke contamination problems, including smoke particle transport in the lungs, particle clogging of heat exchangers in construction vehicles, industrial nanoparticle transport and filtration systems, and dust fouling of electronic systems and MEMS components. Dust fouling of equipment is of particular concern for potential human occupation on dusty planets, such as Mars. The discrete-element method presented in this paper can be used for prediction of aggregate structure and breakup, for prediction of the effect of aggregate formation on the bulk fluid flow, and for prediction of the effects of small-scale flow features (e.g., due to surface roughness or MEMS patterning) on the aggregate formation. After presentation of the overall computational structure, the forces and torques acting on the particles resulting from fluid motion, particle-particle collision, and adhesion under van der Waals forces are reviewed. The effect of various parameters of normal collision and adhesion of two particles are examined in detail. The method is then used to examine aggregate formation and particle clogging in pipe and channel flow.

  17. Discrete-element modeling of particulate aerosol flows

    SciTech Connect

    Marshall, J.S.

    2009-03-20

    A multiple-time step computational approach is presented for efficient discrete-element modeling of aerosol flows containing adhesive solid particles. Adhesive aerosol particulates are found in numerous dust and smoke contamination problems, including smoke particle transport in the lungs, particle clogging of heat exchangers in construction vehicles, industrial nanoparticle transport and filtration systems, and dust fouling of electronic systems and MEMS components. Dust fouling of equipment is of particular concern for potential human occupation on dusty planets, such as Mars. The discrete-element method presented in this paper can be used for prediction of aggregate structure and breakup, for prediction of the effect of aggregate formation on the bulk fluid flow, and for prediction of the effects of small-scale flow features (e.g., due to surface roughness or MEMS patterning) on the aggregate formation. After presentation of the overall computational structure, the forces and torques acting on the particles resulting from fluid motion, particle-particle collision, and adhesion under van der Waals forces are reviewed. The effect of various parameters of normal collision and adhesion of two particles are examined in detail. The method is then used to examine aggregate formation and particle clogging in pipe and channel flow.

  18. Aerosol Measurement and Processing System (AMAPS)

    Atmospheric Science Data Center

    2016-03-22

    Description:  Access aerosol data from MISR and MODIS Subset Level-2 MISR granules by parameter and by space/time region Extract MISR aerosol data for overflights of specific geographic regions or ground site ... or concerns. Details:  Aerosol Measurement and Processing System (AMAPS) Screenshot:  ...

  19. Photochemistry of Model Organic Aerosol Systems

    NASA Astrophysics Data System (ADS)

    Mang, S. A.; Bateman, A. P.; Dailo, M.; Do, T.; Nizkorodov, S. A.; Pan, X.; Underwood, J. S.; Walser, M. L.

    2007-05-01

    Up to 90 percent of urban aerosol particles have been shown to contain organic molecules. Reactions of these particles with atmospheric oxidants and/or sunlight result in large changes in their composition, toxicity, and ability to act as cloud condensation nuclei. For this reason, chemistry of model organic aerosol particles initiated by oxidation and direct photolysis is of great interest to atmospheric, climate, and health scientists. Most studies in this area have focused on identifying the products of oxidation of the organic aerosols, while the products of direct photolysis of the resulting molecules remaining in the aerosol particle have been left mostly unexplored. We have explored direct photolytic processes occurring in selected organic aerosol systems using infrared cavity ringdown spectroscopy to identify small gas phase products of photolysis, and mass-spectrometric and photometric techniques to study the condensed phase products. The first model system was secondary organic aerosol formed from the oxidation of several monoterpenes by ozone in the presence and absence of NOx, under different humidities. The second system modeled after oxidatively aged primary organic aerosol particles was a thin film of either alkanes or saturated fatty acids oxidized in several different ways, with the oxidation initiated by ozone, chlorine atom, or OH. In every case, the general conclusion was that the photochemical processing of model organic aerosols is significant. Such direct photolysis processes are believed to age organic aerosol particles on time scales that are short compared to the particles' atmospheric lifetimes.

  20. Multi-Sensor Aerosol Products Sampling System

    NASA Technical Reports Server (NTRS)

    Petrenko, M.; Ichoku, C.; Leptoukh, G.

    2011-01-01

    Global and local properties of atmospheric aerosols have been extensively observed and measured using both spaceborne and ground-based instruments, especially during the last decade. Unique properties retrieved by the different instruments contribute to an unprecedented availability of the most complete set of complimentary aerosol measurements ever acquired. However, some of these measurements remain underutilized, largely due to the complexities involved in analyzing them synergistically. To characterize the inconsistencies and bridge the gap that exists between the sensors, we have established a Multi-sensor Aerosol Products Sampling System (MAPSS), which consistently samples and generates the spatial statistics (mean, standard deviation, direction and rate of spatial variation, and spatial correlation coefficient) of aerosol products from multiple spacebome sensors, including MODIS (on Terra and Aqua), MISR, OMI, POLDER, CALIOP, and SeaWiFS. Samples of satellite aerosol products are extracted over Aerosol Robotic Network (AERONET) locations as well as over other locations of interest such as those with available ground-based aerosol observations. In this way, MAPSS enables a direct cross-characterization and data integration between Level-2 aerosol observations from multiple sensors. In addition, the available well-characterized co-located ground-based data provides the basis for the integrated validation of these products. This paper explains the sampling methodology and concepts used in MAPSS, and demonstrates specific examples of using MAPSS for an integrated analysis of multiple aerosol products.

  1. Convective flow dominates aerosol delivery to the lung segments

    PubMed Central

    van Ertbruggen, C.; Prisk, G. K.

    2011-01-01

    Most previous computational studies on aerosol transport in models of the central airways of the human lung have focused on deposition, rather than transport of particles through these airways to the subtended lung regions. Using a model of the bronchial tree extending from the trachea to the segmental bronchi (J Appl Physiol 98: 970–980, 2005), we predicted aerosol delivery to the lung segments. Transport of 0.5- to 10-μm-diameter particles was computed at various gravity levels (0–1.6 G) during steady inspiration (100–500 ml/s). For each condition, the normalized aerosol distribution among the lung segments was compared with the normalized flow distribution by calculating the ratio (Ri) of the number of particles exiting each segmental bronchus i to the flow. When Ri = 1, particle transport was directly proportional to segmental flow. Flow and particle characteristics were represented by the Stokes number (Stk) in the trachea. For Stk < 0.01, Ri values were close to 1 and were unaffected by gravity. For Stk > 0.01, Ri varied greatly among the different outlets (Ri = 0.30–1.93 in normal gravity for 10-μm particles at 500 ml/s) and was affected by gravity and inertia. These data suggest that, for Stk < 0.01, ventilation defines the delivery of aerosol to lung segments and that the use of aerosol tracers is a valid technique to visualize ventilation in different parts of the lung. At higher Stokes numbers, inertia, but not gravitational sedimentation, is the second major factor affecting the transport of large particles in the lung. PMID:21474695

  2. Infrared spectroscopic methods for the study of aerosol particles using White cell optics: Development and characterization of a new aerosol flow tube.

    PubMed

    Nájera, Juan J; Fochesatto, Javier G; Last, Deborah J; Percival, Carl J; Horn, Andrew B

    2008-12-01

    A description of a new aerosol flow tube apparatus for measurements in situ under atmospherically relevant conditions is presented here. The system consists of a laboratory-made nebulizer generation system and a flow tube with a White cell-based Fourier transform IR for the detection system. An assessment of the White cell coupled to the flow tube was carried out by an extensive set of experiments to ensure the alignment of the infrared beam and optimize the performance of this system. The detection limit for CO was established as (1.0+/-0.3) ppm and 16 passes was chosen as the optimum number of passes to be used in flow tube experiments. Infrared spectroscopy was used to characterize dry aerosol particles in the flow tube. Pure particles composed of ammonium sulfate or sodium chloride ranging between 0.8 and 2.1 mum for size diameter and (0.8-4.9)x10(6) particles/cm(3) for density number were generated by nebulization of aqueous solutions. Direct measurements of the aerosol particle size agree with size spectra retrieved from inversion of the extinction measurements using Mie calculations, where the difference residual value is in the order of 0.2%. The infrared detection limit for ammonium sulfate aerosol particles was determined as d(p)=0.9 mum and N=5x10(3) particles/cm(3) with sigma=1.1 by Mie calculation. Alternatively, Mie calculations were performed to determine the flexibility in varying the optical length when aerosol particles are sent by the injector. The very good agreement between the values retrieved for aerosol particles injected through the flow tube or through the injector clearly validates the estimation of the effective optical path length for the injector. To determine the flexibility in varying the reaction zone length, analysis of the extinction spectra as function of the position of the injector was carried out by monitoring the integrated area of different absorption modes of the ammonium sulfate. We conclude that the aerosol loss in the

  3. A satellite view of aerosols in the climate system

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Tanre, Didier; Boucher, Olivier

    2002-01-01

    Anthropogenic aerosols are intricately linked to the climate system and to the hydrologic cycle. The net effect of aerosols is to cool the climate system by reflecting sunlight. Depending on their composition, aerosols can also absorb sunlight in the atmosphere, further cooling the surface but warming the atmosphere in the process. These effects of aerosols on the temperature profile, along with the role of aerosols as cloud condensation nuclei, impact the hydrologic cycle, through changes in cloud cover, cloud properties and precipitation. Unravelling these feedbacks is particularly difficult because aerosols take a multitude of shapes and forms, ranging from desert dust to urban pollution, and because aerosol concentrations vary strongly over time and space. To accurately study aerosol distribution and composition therefore requires continuous observations from satellites, networks of ground-based instruments and dedicated field experiments. Increases in aerosol concentration and changes in their composition, driven by industrialization and an expanding population, may adversely affect the Earth's climate and water supply.

  4. Numerical Investigation of Sheath and Aerosol Flows in the Flow Combination Section of a Baron Fiber Classifier

    PubMed Central

    Dubey, Prahit; Ghia, Urmila; Turkevich, Leonid A.

    2015-01-01

    The Baron fiber classifier is an instrument used to separate fibers by length. The flow combination section (FCS) of this instrument is an upstream annular region, where an aerosol of uncharged fibers is introduced along with two sheath flows; length separation occurs by dielectrophoresis downstream in the flow classification section. In its current implementation at NIOSH, the instrument is capable of processing only very small quantities of fibers. In order to prepare large quantities of length-separated fibers for toxicological studies, the throughput of the instrument needs to be increased, and hence, higher aerosol flow rates need to be considered. However, higher aerosol flow rates may give rise to flow separation or vortex formation in the FCS, arising from the sudden expansion of the aerosol at the inlet nozzle. The goal of the present investigation is to understand the interaction of the sheath and aerosol flows inside the FCS, using computational fluid dynamics (CFD), and to identify possible limits to increasing aerosol flow rates. Numerical solutions are obtained using an axisymmetric model of the FCS, and solving the Navier-Stokes equations governing these flows; in this study, the aerosol flow is treated purely aerodynamically. Results of computations are presented for four different flow rates. The geometry of the converging outer cylinder, along with the two sheath flows, is effective in preventing vortex formation in the FCS for aerosol-to-sheath flow inlet velocity ratios below ~ 50. For higher aerosol flow rates, recirculation is observed in both inner and outer sheaths. Results for velocity, streamlines, and shear stress are presented. PMID:26388662

  5. Generation and characterization of large-particle aerosols using a center flow tangential aerosol generator with a nonhuman-primate, head-only aerosol chamber

    PubMed Central

    Bohannon, J. Kyle; Lackemeyer, Matthew G.; Kuhn, Jens H.; Wada, Jiro; Bollinger, Laura; Jahrling, Peter B.; Johnson, Reed F.

    2016-01-01

    Aerosol droplets or particles produced from infected respiratory secretions have the potential to infect another host through inhalation. These respiratory particles can be polydisperse and range from 0.05–500 μm in diameter. Animal models of infection are generally established to facilitate the potential licensure of candidate prophylactics and/or therapeutics. Consequently, aerosol-based animal infection models are needed to properly study and counter airborne infections. Ideally, experimental aerosol exposure should reliably result in animal disease that faithfully reproduces the modelled human disease. Few studies have been performed to explore the relationship between exposure particle size and induced disease course for infectious aerosol particles. The center flow tangential aerosol generator (CenTAG™) produces large-particle aerosols capable of safely delivering a variety of infectious aerosols to nonhuman primates within a Class III Biological Safety Cabinet (BSC) for establishment or refinement of nonhuman primate infectious disease models. Here we report the adaptation of this technology to the Animal Biosafety Level 4 (ABSL-4) environment for the future study of high-consequence viral pathogens and the characterization of CenTAG™-created sham (no animal, no virus) aerosols using a variety of viral growth media and media supplements. PMID:25970823

  6. Generation and characterization of large-particle aerosols using a center flow tangential aerosol generator with a non-human-primate, head-only aerosol chamber.

    PubMed

    Bohannon, J Kyle; Lackemeyer, Matthew G; Kuhn, Jens H; Wada, Jiro; Bollinger, Laura; Jahrling, Peter B; Johnson, Reed F

    2015-01-01

    Aerosol droplets or particles produced from infected respiratory secretions have the potential to infect another host through inhalation. These respiratory particles can be polydisperse and range from 0.05 to 500 µm in diameter. Animal models of infection are generally established to facilitate the potential licensure of candidate prophylactics and/or therapeutics. Consequently, aerosol-based animal infection models are needed to properly study and counter airborne infections. Ideally, experimental aerosol exposure should reliably result in animal disease that faithfully reproduces the modeled human disease. Few studies have been performed to explore the relationship between exposure particle size and induced disease course for infectious aerosol particles. The center flow tangential aerosol generator (CenTAG™) produces large-particle aerosols capable of safely delivering a variety of infectious aerosols to non-human primates (NHPs) within a Class III Biological Safety Cabinet (BSC) for establishment or refinement of NHP infectious disease models. Here, we report the adaptation of this technology to the Animal Biosafety Level 4 (ABSL-4) environment for the future study of high-consequence viral pathogens and the characterization of CenTAG™-created sham (no animal, no virus) aerosols using a variety of viral growth media and media supplements. PMID:25970823

  7. Ionization detection system for aerosols

    DOEpatents

    Jacobs, Martin E.

    1977-01-01

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system utilizes a measuring ionization chamber which is modified to minimize false alarms and reductions in sensitivity resulting from changes in ambient temperature. In the preferred form of the modification, an annular radiation shield is mounted about the usual radiation source provided to effect ionization in the measuring chamber. The shield is supported by a bimetallic strip which flexes in response to changes in ambient temperature, moving the shield relative to the source so as to vary the radiative area of the source in a manner offsetting temperature-induced variations in the sensitivity of the chamber.

  8. The Pharmaceutical Aerosol Deposition Device on Cell Cultures (PADDOCC) in vitro system: design and experimental protocol.

    PubMed

    Hein, Stephanie; Bur, Michael; Kolb, Tobias; Muellinger, Bernhard; Schaefer, Ulrich F; Lehr, Claus-Michael

    2010-08-01

    The development of aerosol medicines typically involves numerous tests on animals, due to the lack of adequate in vitro models. A new in vitro method for testing pharmaceutical aerosol formulations on cell cultures was developed, consisting of an aerosolisation unit fitting a commercial dry powder inhaler (HandiHaler(c), Boehringer Ingelheim, Germany), an air-flow control unit (Akita(c), Activaero, Germany) and a custom-made sedimentation chamber. This chamber holds three Snapwell(c) inserts with monolayers of pulmonary epithelial cells. The whole set-up, referred to as the Pharmaceutical Aerosol Deposition Device On Cell Cultures (PADDOCC) system, aims to mimic the complete process of aerosol drug delivery, encompassing aerosol generation, aerosol deposition onto pulmonary epithelial cells and subsequent drug transport across this biological barrier, to facilitate the investigation of new aerosol formulations in the early stages of development. We describe here, the development of the design and the protocol for this device. By testing aerosol formulations of budesonide and salbutamol sulphate, respectively, reproducible deposition of aerosol particles on, and the integrity of, the pulmonary cell monolayer could be demonstrated. PMID:20822321

  9. Respiratory flows during early childhood: Computational models to examine therapeutic aerosols in the developing airways

    NASA Astrophysics Data System (ADS)

    Tenenbaum-Katan, Janna; Hofemeier, Philipp; Sznitman, Josué; Janna Tenenbaum-Katan Team

    2015-11-01

    Inhalation therapy is the cornerstone of early-childhood respiratory treatments, as well as a rising potential for systemic drug delivery and pulmonary vaccination. As such, indispensable understanding of respiratory flow phenomena, coupled with particle transport at the deep regions of children's lungs is necessary to attain efficient targeting of aerosol therapy. However, fundamental research of pulmonary transport is overwhelmingly focused on adults. In our study, we have developed an anatomically-inspired computational model of representing pulmonary acinar regions at several age points during a child's development. Our numerical simulations examine respiratory flows and particle deposition maps within the acinar model, accounting for varying age dependant anatomical considerations and ventilation patterns. Resulting deposition maps of aerosols alter with age, such findings might suggest that medication protocols of inhalation therapy in young children should be considered to be accordingly amended with the child's development. Additionally to understanding basic scientific concepts of age effects on aerosol deposition, our research can potentially contribute practical guidelines to therapy protocols, and its' necessary modifications with age. We acknowledge the support of the ISF and the Israeli ministry of Science.

  10. Ultrasonic flow metering system

    DOEpatents

    Gomm, Tyler J.; Kraft, Nancy C.; Mauseth, Jason A.; Phelps, Larry D.; Taylor, Steven C.

    2002-01-01

    A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters and receivers, one of which is set at an angle to the direction of flow that is different from the others.

  11. An analysis of lift forces on aerosols in a wall bounded turbulent shear flow

    SciTech Connect

    Cherukat, P.; McLaughlin, J.B.

    1992-12-31

    This paper describes work that will lead to a better understanding of the role of lift forces in the deposition of aerosols on the walls bounding a turbulent shear flow. After providing some background information about aerosol trajectories that has been obtained from computer simulations, new results for the lift force in the relevant parameter ranges are presented.

  12. An analysis of lift forces on aerosols in a wall bounded turbulent shear flow

    SciTech Connect

    Cherukat, P.; McLaughlin, J.B.

    1992-01-01

    This paper describes work that will lead to a better understanding of the role of lift forces in the deposition of aerosols on the walls bounding a turbulent shear flow. After providing some background information about aerosol trajectories that has been obtained from computer simulations, new results for the lift force in the relevant parameter ranges are presented.

  13. AEROSOL GROWTH IN A STEADY-STATE, CONTINUOUS FLOW CHAMBER: APPLICATION TO STUDIES OF SECONDARY AEROSOL FORMATION

    EPA Science Inventory

    An analytical solution for the steady-state aerosol size distribution achieved in a steady-state, continuous flow chamber is derived, where particle growth is occurring by gas-to-particle conversion and particle loss is occurring by deposition to the walls of the chamber. The s...

  14. Near Real Time Vertical Profiles of Clouds and Aerosols from the Cloud-Aerosol Transport System (CATS) on the International Space Station

    NASA Astrophysics Data System (ADS)

    Yorks, J. E.; McGill, M. J.; Nowottnick, E. P.

    2015-12-01

    Plumes from hazardous events, such as ash from volcanic eruptions and smoke from wildfires, can have a profound impact on the climate system, human health and the economy. Global aerosol transport models are very useful for tracking hazardous plumes and predicting the transport of these plumes. However aerosol vertical distributions and optical properties are a major weakness of global aerosol transport models, yet a key component of tracking and forecasting smoke and ash. The Cloud-Aerosol Transport System (CATS) is an elastic backscatter lidar designed to provide vertical profiles of clouds and aerosols while also demonstrating new in-space technologies for future Earth Science missions. CATS has been operating on the Japanese Experiment Module - Exposed Facility (JEM-EF) of the International Space Station (ISS) since early February 2015. The ISS orbit provides more comprehensive coverage of the tropics and mid-latitudes than sun-synchronous orbiting sensors, with nearly a three-day repeat cycle. The ISS orbit also provides CATS with excellent coverage over the primary aerosol transport tracks, mid-latitude storm tracks, and tropical convection. Data from CATS is used to derive properties of clouds and aerosols including: layer height, layer thickness, backscatter, optical depth, extinction, and depolarization-based discrimination of particle type. The measurements of atmospheric clouds and aerosols provided by the CATS payload have demonstrated several science benefits. CATS provides near-real-time observations of cloud and aerosol vertical distributions that can be used as inputs to global models. The infrastructure of the ISS allows CATS data to be captured, transmitted, and received at the CATS ground station within several minutes of data collection. The CATS backscatter and vertical feature mask are part of a customized near real time (NRT) product that the CATS processing team produces within 6 hours of collection. The continuous near real time CATS data

  15. Development of a Scheimpflug Lidar System for Atmospheric Aerosol Monitoring

    NASA Astrophysics Data System (ADS)

    Mei, Liang; Brydegaard, Mikkel

    2016-06-01

    This work presents a Scheimpflug lidar system which was employed for atmospheric aerosol monitoring in southern Sweden. Atmospheric aerosol fluctuation was observed around rush-hour. The extinction coefficient over 6 km was retrieved, i.e., 0.15 km-1, by employing the slop-method during the time when the atmosphere was relatively homogenous. The measurements successfully demonstrate the potential of using a Scheimpflug lidar technique for atmospheric aerosol monitoring applications.

  16. Aerosol mass spectrometry systems and methods

    SciTech Connect

    Fergenson, David P.; Gard, Eric E.

    2013-08-20

    A system according to one embodiment includes a particle accelerator that directs a succession of polydisperse aerosol particles along a predetermined particle path; multiple tracking lasers for generating beams of light across the particle path; an optical detector positioned adjacent the particle path for detecting impingement of the beams of light on individual particles; a desorption laser for generating a beam of desorbing light across the particle path about coaxial with a beam of light produced by one of the tracking lasers; and a controller, responsive to detection of a signal produced by the optical detector, that controls the desorption laser to generate the beam of desorbing light. Additional systems and methods are also disclosed.

  17. Neutral and charged binary sulfate aerosol nucleation in the aerosol-climate modeling system ECHAM5-HAM

    NASA Astrophysics Data System (ADS)

    Kazil, J.; Kokkola, H.

    2007-12-01

    Aerosol particles play an important role in the Earth's atmosphere and in the climate system: Aerosols scatter and absorb solar radiation, facilitate heterogeneous and multiphase chemistry, and change cloud characteristics in many ways. Aerosol particles can be directly emitted from surface sources (primary aerosol) or form from the gas phase (secondary aerosol). Secondary aerosol formation can significantly increase concentrations of cloud condensation nuclei. Two important pathways of aerosol formation from the gas phase are neutral and charged binary nucleation of sulfuric acid and water. We have introduced laboratory data based representations of these pathways into the aerosol-climate modeling system ECHAM5-HAM, and investigate their relative importance and spatial distribution in the troposphere, and discuss ramifications for processes in the Earth's atmosphere.

  18. Gas Flow Detection System

    NASA Technical Reports Server (NTRS)

    Moss, Thomas; Ihlefeld, Curtis; Slack, Barry

    2010-01-01

    This system provides a portable means to detect gas flow through a thin-walled tube without breaking into the tubing system. The flow detection system was specifically designed to detect flow through two parallel branches of a manifold with only one inlet and outlet, and is a means for verifying a space shuttle program requirement that saves time and reduces the risk of flight hardware damage compared to the current means of requirement verification. The prototype Purge Vent and Drain Window Cavity Conditioning System (PVD WCCS) Flow Detection System consists of a heater and a temperature-sensing thermistor attached to a piece of Velcro to be attached to each branch of a WCCS manifold for the duration of the requirement verification test. The heaters and thermistors are connected to a shielded cable and then to an electronics enclosure, which contains the power supplies, relays, and circuit board to provide power, signal conditioning, and control. The electronics enclosure is then connected to a commercial data acquisition box to provide analog to digital conversion as well as digital control. This data acquisition box is then connected to a commercial laptop running a custom application created using National Instruments LabVIEW. The operation of the PVD WCCS Flow Detection System consists of first attaching a heater/thermistor assembly to each of the two branches of one manifold while there is no flow through the manifold. Next, the software application running on the laptop is used to turn on the heaters and to monitor the manifold branch temperatures. When the system has reached thermal equilibrium, the software application s graphical user interface (GUI) will indicate that the branch temperatures are stable. The operator can then physically open the flow control valve to initiate the test flow of gaseous nitrogen (GN2) through the manifold. Next, the software user interface will be monitored for stable temperature indications when the system is again at

  19. The Cloud-Aerosol Transport System (CATS): Demonstrating New Techniques for Cloud and Aerosol Measurements

    NASA Astrophysics Data System (ADS)

    Yorks, J. E.; McGill, M. J.; Palm, S. P.; Hlavka, D. L.; Nowottnick, E. P.; Selmer, P. A.

    2015-12-01

    The Cloud-Aerosol Transport System (CATS) is an elastic backscatter lidar that provides vertical profiles of cloud and aerosol properties. The CATS payload has been operating since early February 2015 from the International Space Station (ISS). CATS was designed to operate for six months, and up to three years, providing a combination of operational science, in-space technology demonstration, and technology risk reduction for future Earth Science missions. One of the primary project goals of CATS is to demonstrate technology in support of future space-based lidar mission development. The CATS instrument has been demonstrating the high repetition rate laser and photon counting detection approach to lidar observations, in contrast to the low repetition rate, high energy technique employed by CALIPSO. Due to this technique, cloud and aerosol profile data exhibit high spatial and temporal resolution, which was never before possible from a space-based platform. Another important science goal of the CATS-FO project is accurate determination of aerosol type on a global scale. CATS provided the first space-based depolarization measurements at multiple wavelengths (532 and 1064 nm), and first measurements at 1064 nm from space. The ratio of the depolarization measurements at these two wavelengths enables significant improvement in aerosol typing. The CATS retrievals at 1064 nm also provide improvements to detecting aerosols above clouds. The CATS layer identification algorithm is a threshold-based layer detection method that uses the 1064 nm attenuated scattering ratio and also includes a routine to identify clouds embedded within aerosol layers. This technique allows CATS to detect the full extent of the aerosol layers above the cloud, and differentiate these two layers so that the optical properties can be more accurately determined.

  20. Meteorological and Aerosol Sensing with small Unmanned Aerial Systems

    NASA Astrophysics Data System (ADS)

    Born, J.; Möhler, O.; Haunold, W.; Schrod, J.; Brooks, I.; Norris, S.; Brooks, B.; Hill, M.; Leisner, T.

    2012-04-01

    Unmanned Aerial Systems (UAS) facilitate the monitoring of several meteorological and aerosol parameters with high resolution in space and time. They are small, easy to operate, cost efficient and allow for flexible application during field campaigns. We present two experimental payloads for measurement of relative humidity, temperature, aerosol size distribution and the collection of aerosol samples on board the small UAS SIRIUS II. The payload modules are light weight (<1kg) and can be easily switched between two flights. All sensors can be controlled from the ground and the measured data is recorded by the autopilot together with the position data. The first module contains a sensor package for measurement of relative humidity and temperature and the Compact Lightweight Aerosol Spectrometer Prope (CLASP) for acquisition of aerosol size distributions. CLASP measures aerosol particles with diameters from 0.12μm to 9.25μm in up to 32 channels at a frequency of 10 Hz. The second module also contains a humidity and temperature sensor package and the aerosol sample collection device. The aerosol sampler collects air samples at 2 l/min onto a sample holder. After the flight the ice nuclei on the sample holder are activated in the lab and counted. In August 2012 the complete setup will be used during a measurement campaign at mount "Kleiner Feldberg" close to Frankfurt. Until then we will perform test flights and additional laboratory tests.

  1. Aerosol generation by blower motors as a bias in assessing aerosol penetration into cabin filtration systems.

    PubMed

    Heitbrink, William A; Collingwood, Scott

    2005-01-01

    In cabin filtration systems, blower motors pressurize a vehicle cabin with clean filtered air and recirculate air through an air-conditioning evaporator coil and a heater core. The exposure reduction offered by these cabins is evaluated by optical particle counters that measure size-dependent aerosol concentration inside and outside the cabin. The ratio of the inside-to-outside concentration is termed penetration. Blower motors use stationary carbon brushes to transmit an electrical current through a rotating armature that abrades the carbon brushes. This creates airborne dust that may affect experimental evaluations of aerosol penetration. To evaluate the magnitude of these dust emissions, blower motors were placed in a test chamber and operated at 12 and 13.5 volts DC. A vacuum cleaner drew 76 m3/hour (45 cfm) of air through HEPA filters, the test chamber, and through a 5 cm diameter pipe. An optical particle counter drew air through an isokinetic sampling probe and measured the size-dependent particle concentrations from 0.3 to 15 microm. The concentration of blower motor aerosol was between 2 x 10(5) and 1.8 x 10(6) particles/m3. Aerosol penetration into three stationary vehicles, two pesticide application vehicles and one tractor were measured at two conditions: low concentration (outside in the winter) and high concentration (inside repair shops and burning incense sticks used as a supplemental aerosol source). For particles smaller than 1 microm, the in-cabin concentrations can be explained by the blower motor emissions. For particles larger than 1 microm, other aerosol sources, such as resuspended dirt, are present. Aerosol generated by the operation of the blower motor and by other sources can bias the exposure reduction measured by optical particle counters. PMID:15764523

  2. A Randomized Double-Blind Placebo-Controlled Dose-Escalation Phase 1 Study of Aerosolized Amikacin and Fosfomycin Delivered via the PARI Investigational eFlow® Inline Nebulizer System in Mechanically Ventilated Patients

    PubMed Central

    Vallance, Shirley; Abuan, Tammy; Tservistas, Markus; Davies, Andrew

    2014-01-01

    Abstract Background: This clinical trial evaluated the pharmacokinetics and safety/tolerability of amikacin/fosfomycin solution using a vibrating plate nebulizer, in mechanically ventilated patients with ventilator-associated tracheobronchitis (VAT) or ventilator-associated pneumonia (VAP). Methods: Nine adult patients were consented to receive three escalating doses of a combination of 50 mg/mL amikacin and 20 mg/mL fosfomycin; doses were separated by 24±2 hr. On day 3, patients received two blinded, randomized treatments (amikacin/fosfomycin and volume-matched placebo), separated by 2 hr. All treatments were administered with a single-patient, multitreatment nebulizer (Investigational eFlow® Inline Nebulizer System; PARI Pharma GmbH, positioned in the inspiratory limb tubing between the ventilator and the patient. The nebulizer remained in-line until all treatments had been delivered. Concentrations of amikacin and fosfomycin were measured in tracheal aspirate and plasma samples obtained during the 24 hr after each dose. Results: Fifteen minutes after dosing with the 300/120 mg amikacin/fosfomycin combination, tracheal aspirate amikacin concentrations±SD were 12,390±3,986 μg/g, and fosfomycin concentrations were 6,174±2,548 μg/g (n=6). Airway clearance was rapid. Plasma concentrations were subtherapeutic; the highest observed amikacin plasma concentration was 1.4 μg/mL, and the highest observed fosfomycin plasma concentration was 0.8 μg/mL. Administration time was approximately 2 min/mL. No adverse effects on respiratory rate, peak airway pressures, or oxygenation were observed during or following drug or placebo administration. Conclusions: High tracheal aspirate concentrations of amikacin and fosfomycin were achieved in mechanically ventilated patients with VAT or VAP after aerosolized administration with an inline nebulizer system. Airway clearance was rapid. No adverse respiratory effects were noted during or following drug

  3. Development of the aerosol generation system for simulating the dry deposition behavior of radioaerosol emitted by the accident of FDNPP

    NASA Astrophysics Data System (ADS)

    Zhang, Z.

    2015-12-01

    A large amount of radioactivity was discharged by the accident of FDNPP. The long half-life radionuclide, 137Cs was transported through the atmosphere mainly as the aerosol form and deposited to the forests in Fukushima prefecture. After the dry deposition of the 137Cs, the foliar uptake process would occur. To evaluate environmental transfer of radionuclides, the dry deposition and following foliar uptake is very important. There are some pioneering studies for radionuclide foliar uptake with attaching the solution containing stable target element on the leaf, however, cesium oxide aerosols were used for these deposition study [1]. In the FDNPP case, 137Cs was transported in sulfate aerosol form [2], so the oxide aerosol behaviors could not represent the actual deposition behavior in this accident. For evaluation of whole behavior of 137Cs in vegetation system, fundamental data for deposition and uptake process of sulfate aerosol was desired. In this study, we developed aerosol generation system for simulating the dry deposition and the foliar uptake behaviors of aerosol in the different chemical constitutions. In this system, the method of aerosol generation based on the spray drying. Solution contained 137Cs was send to a nozzle by a syringe pump and spraying with a high speed air flow. The sprayed mist was generated in a chamber in the relatively high temperature. The solution in the mist was dried quickly, and micro size solid aerosols consisting 137Cs were generated. The aerosols were suctioned by an ejector and transported inside a tube by the dry air flow, then were directly blown onto the leaves. The experimental condition, such as the size of chamber, chamber temperature, solution flow rate, air flow rate and so on, were optimized. In the deposition experiment, the aerosols on leaves were observed by a SEM/EDX system and the deposition amount was evaluated by measuring the stable Cs remaining on leaf. In the presentation, we will discuss the detail

  4. Hand calculations for transport of radioactive aerosols through sampling systems.

    PubMed

    Hogue, Mark; Thompson, Martha; Farfan, Eduardo; Hadlock, Dennis

    2014-05-01

    Workplace air monitoring programs for sampling radioactive aerosols in nuclear facilities sometimes must rely on sampling systems to move the air to a sample filter in a safe and convenient location. These systems may consist of probes, straight tubing, bends, contractions and other components. Evaluation of these systems for potential loss of radioactive aerosols is important because significant losses can occur. However, it can be very difficult to find fully described equations to model a system manually for a single particle size and even more difficult to evaluate total system efficiency for a polydispersed particle distribution. Some software methods are available, but they may not be directly applicable to the components being evaluated and they may not be completely documented or validated per current software quality assurance requirements. This paper offers a method to model radioactive aerosol transport in sampling systems that is transparent and easily updated with the most applicable models. Calculations are shown with the R Programming Language, but the method is adaptable to other scripting languages. The method has the advantage of transparency and easy verifiability. This paper shows how a set of equations from published aerosol science models may be applied to aspiration and transport efficiency of aerosols in common air sampling system components. An example application using R calculation scripts is demonstrated. The R scripts are provided as electronic attachments. PMID:24667389

  5. Application of flow cytometry and cell sorting to the bacterial analysis of environmental aerosol samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flow cytometry (FCM) combined with viability staining is a useful tool in discerning viable bacteria in environmental samples where traditional culture methods may fail. Contamination of aerosol samples with dust and other non-biological particles can interfere with accurate sample analysis and ther...

  6. A humidity controlled Nephelometer system to study the hygroscopic properties of aerosols in the marine environment

    NASA Astrophysics Data System (ADS)

    Vaishya, Aditya; O'Dowd, Colin; Jennings, S. Gerard

    2010-05-01

    A Humidograph system has been designed to study the hygroscopic properties of aerosols for different air-masses and for different seasons in the marine environment. Since ambient marine aerosols are likely to be found in a metastable state, and in accordance with recommendations of WMO/GAW to sample dry aerosol, a drying unit (Nafion based) is placed just after the inlet to dry the aerosols to a relative humidity (RH) < 40% so as not to misinterpret the optical properties of hygroscopic aerosols if they are on the descending branch of the hysteresis curve. The flow after the dryer is split into two, one going to a 3-wavelength TSI-3563 Integrating Nephelometer, and the other to a Gore-Tex based humidifier followed by a single-wavelength TSI-3561 Integrating Nephelometer. The humidifier is used to vary the RH from 40% to 90%. While the TSI-3563 Integrating Nephelometer will operate at RH < 40%, the TSI-3561 Integrating Nephelometer will operate under varying RH conditions. Software developed in LabVIEW is used to control the hardware components and to log the data in a predefined format. Results of the performance of the Humidograph system in the laboratory and at the Mace Head Atmospheric Research Station are presented.

  7. In situ measurement of the infrared absorption and extinction of chemical and biologically derived aerosols using flow-through photoacoustics.

    PubMed

    Gurton, Kristan P; Dahmani, Rachid; Ligon, David; Bronk, Burt V

    2005-07-01

    In an effort to establish a more reliable set of optical cross sections for a variety of chemical and biological aerosol simulants, we have developed a flow-through photoacoustic system that is capable of measuring absolute, mass-normalized extinction and absorption cross sections. By employing a flow-through design we avoid issues associated with closed aerosol photoacoustic systems and improve sensitivity. Although the results shown here were obtained for the tunable CO2 laser waveband region, i.e., 9.20-10.80 microm, application to other wavelengths is easily achievable. The aerosols considered are categorized as biological, chemical, and inorganic in origin, i.e., Bacillus atrophaeus endospores, dimethicone silicone oil (SF-96 grade 50), and kaolin clay powder (alumina and silicate), respectively. Results compare well with spectral extinction measured previously by Fourier-transform infrared spectroscopy. Comparisons with Mie theory calculations based on previously published complex indices of refraction and measured size distributions are also presented. PMID:16004057

  8. Aerosol identification using a hybrid active/passive system

    NASA Astrophysics Data System (ADS)

    D'Amico, Francis M.; Moon, Raphael P.; Davidson, Charles E.

    2005-08-01

    Recent experimental work has shown that passive systems such as hyperspectral FTIR and frequency-tunable IR cameras have application in detection of biological aerosols. This provided the motivation for a new detection technique, which we call Aerosol Ranging Spectroscopy (ARS), whereby a scattering LIDAR is used to augment passive spectrometer data to determine the location and optical depth of the aerosol plume. When the two systems are co-aligned or boresighted, the hybrid data product provides valuable enhancements for signal exploitation of the passive spectral data. This paper presents the motivation and theoretical basis for the ARS technique. A prototype implementation of an ARS system will also be described, along with preliminary results from recent outdoor field experiments.

  9. Atmospheric aerosol profiling with a bistatic imaging lidar system.

    PubMed

    Barnes, John E; Sharma, N C Parikh; Kaplan, Trevor B

    2007-05-20

    Atmospheric aerosols have been profiled using a simple, imaging, bistatic lidar system. A vertical laser beam is imaged onto a charge-coupled-device camera from the ground to the zenith with a wide-angle lens (CLidar). The altitudes are derived geometrically from the position of the camera and laser with submeter resolution near the ground. The system requires no overlap correction needed in monostatic lidar systems and needs a much smaller dynamic range. Nighttime measurements of both molecular and aerosol scattering were made at Mauna Loa Observatory. The CLidar aerosol total scatter compares very well with a nephelometer measuring at 10 m above the ground. The results build on earlier work that compared purely molecular scattered light to theory, and detail instrument improvements. PMID:17514239

  10. Evaluations of tropospheric aerosol properties simulated by the community earth system model with a sectional aerosol microphysics scheme

    NASA Astrophysics Data System (ADS)

    Yu, Pengfei; Toon, Owen B.; Bardeen, Charles G.; Mills, Michael J.; Fan, Tianyi; English, Jason M.; Neely, Ryan R.

    2015-06-01

    A sectional aerosol model (CARMA) has been developed and coupled with the Community Earth System Model (CESM1). Aerosol microphysics, radiative properties, and interactions with clouds are simulated in the size-resolving model. The model described here uses 20 particle size bins for each aerosol component including freshly nucleated sulfate particles, as well as mixed particles containing sulfate, primary organics, black carbon, dust, and sea salt. The model also includes five types of bulk secondary organic aerosols with four volatility bins. The overall cost of CESM1-CARMA is approximately ˜2.6 times as much computer time as the standard three-mode aerosol model in CESM1 (CESM1-MAM3) and twice as much computer time as the seven-mode aerosol model in CESM1 (CESM1-MAM7) using similar gas phase chemistry codes. Aerosol spatial-temporal distributions are simulated and compared with a large set of observations from satellites, ground-based measurements, and airborne field campaigns. Simulated annual average aerosol optical depths are lower than MODIS/MISR satellite observations and AERONET observations by ˜32%. This difference is within the uncertainty of the satellite observations. CESM1/CARMA reproduces sulfate aerosol mass within 8%, organic aerosol mass within 20%, and black carbon aerosol mass within 50% compared with a multiyear average of the IMPROVE/EPA data over United States, but differences vary considerably at individual locations. Other data sets show similar levels of comparison with model simulations. The model suggests that in addition to sulfate, organic aerosols also significantly contribute to aerosol mass in the tropical UTLS, which is consistent with limited data.

  11. A study of a singlet-oxygen generator with a twisted aerosol flow

    SciTech Connect

    Adamenkov, A A; Vyskubenko, B A; Il'in, S P; Krukovskii, I M

    2002-06-30

    The results of a study of a singlet-oxygen generator (SOG) with a twisted aerosol flow are presented. The output parameters of the generator obtained in experiments exceed the corresponding characteristics reported earlier in the literature. The maximum chemical efficiency of the reactor amounts to {approx} 70%. The flux density of the electron energy stored by the excited oxygen molecules in the reaction zone is above 1.5 kJ cm{sup -2} s{sup -1}. The measured singlet-oxygen yield is {approx} 60% at a pressure of 100 Torr. Adding a buffer gas (N{sub 2}) to chlorine ensures an increase in the outlet pressure up to 250 Torr without a decrease in the singlet-oxygen yield. The utilisation of chlorine under such conditions exceeds 95 %. The SOG design with a twisted flow ensures atmospheric pressure of the waste solution at the reactor outlet, thus significantly simplifying the development of a system for liquid recycling. (active media)

  12. Atmospheric aerosol monitoring by an elastic Scheimpflug lidar system.

    PubMed

    Mei, Liang; Brydegaard, Mikkel

    2015-11-30

    This work demonstrates a new approach - Scheimpflug lidar - for atmospheric aerosol monitoring. The atmospheric backscattering echo of a high-power continuous-wave laser diode is received by a Newtonian telescope and recorded by a tilted imaging sensor satisfying the Scheimpflug condition. The principles as well as the lidar equation are discussed in details. A Scheimpflug lidar system operating at around 808 nm is developed and employed for continuous atmospheric aerosol monitoring at daytime. Localized emission, atmospheric variation, as well as the changes of cloud height are observed from the recorded lidar signals. The extinction coefficient is retrieved according to the slope method for a homogeneous atmosphere. This work opens up new possibilities of using a compact and robust Scheimpflug lidar system for atmospheric aerosol remote sensing. PMID:26698808

  13. Ellipsoidal cell flow system

    DOEpatents

    Salzman, Gary C.; Mullaney, Paul F.

    1976-01-01

    The disclosure relates to a system incorporating an ellipsoidal flow chamber having light reflective walls for low level light detection in practicing cellular analysis. The system increases signal-to-noise ratio by a factor of ten over prior art systems. In operation, laser light passes through the primary focus of the ellipsoid. A controlled flow of cells simultaneously passes through this focus so that the laser light impinges on the cells and is modulated by the cells. The reflective walls of the ellipsoid reflect the cell-modulated light to the secondary focus of the ellipsoid. A tapered light guide at the secondary focus picks up a substantial portion of modulated reflective light and directs it onto a light detector to produce a signal. The signal is processed to obtain the intensity distribution of the modulated light and hence sought after characteristics of the cells. In addition, cells may be dyed so as to fluoresce in response to the laser light and their fluorescence may be processed as cell-modulated light above described. A light discriminating filter would be used to distinguish reflected modulated laser light from reflected fluorescent light.

  14. The Aerosol-Monsoon Climate System of Asia

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kyu-Myong, Kim

    2012-01-01

    In Asian monsoon countries such as China and India, human health and safety problems caused by air-pollution are worsening due to the increased loading of atmospheric pollutants stemming from rising energy demand associated with the rapid pace of industrialization and modernization. Meanwhile, uneven distribution of monsoon rain associated with flash flood or prolonged drought, has caused major loss of human lives, and damages in crop and properties with devastating societal impacts on Asian countries. Historically, air-pollution and monsoon research are treated as separate problems. However a growing number of recent studies have suggested that the two problems may be intrinsically intertwined and need to be studied jointly. Because of complexity of the dynamics of the monsoon systems, aerosol impacts on monsoons and vice versa must be studied and understood in the context of aerosol forcing in relationship to changes in fundamental driving forces of the monsoon climate system (e.g. sea surface temperature, land-sea contrast etc.) on time scales from intraseasonal variability (weeks) to climate change ( multi-decades). Indeed, because of the large contributions of aerosols to the global and regional energy balance of the atmosphere and earth surface, and possible effects of the microphysics of clouds and precipitation, a better understanding of the response to climate change in Asian monsoon regions requires that aerosols be considered as an integral component of a fully coupled aerosol-monsoon system on all time scales. In this paper, using observations and results from climate modeling, we will discuss the coherent variability of the coupled aerosol-monsoon climate system in South Asia and East Asia, including aerosol distribution and types, with respect to rainfall, moisture, winds, land-sea thermal contrast, heat sources and sink distributions in the atmosphere in seasonal, interannual to climate change time scales. We will show examples of how elevated

  15. Simulation test of aerosol generation from vessels in the pre-treatment system of fuel reprocessing

    SciTech Connect

    Fujine, Sachio; Kitamura, Koichiro; Kihara, Takehiro

    1997-08-01

    Aerosol concentration and droplet size are measured in off-gas of vessel under various conditions by changing off-gas flow rate, stirring air flow rate, salts concentration and temperature of nitrate solution. Aerosols are also measured under evaporation and air-lift operation. 4 refs., 6 figs.

  16. Modeling aerosol formation in opposed-flow diffusion flames.

    PubMed

    Violi, Angela; D'Anna, Andrea; D'Alessio, Antonio; Sarofim, Adel F

    2003-06-01

    The microstructures of atmospheric pressure, counter-flow, sooting, flat, laminar ethylene diffusion flames have been studied numerically by using a new kinetic model developed for hydrocarbon oxidation and pyrolysis. Modeling results are in reasonable agreement with experimental data in terms of concentration profiles of stable species and gas-phase aromatic compounds. Modeling results are used to analyze the controlling steps of aromatic formation and soot growth in counter-flow configurations. The formation of high molecular mass aromatics in diffusion controlled conditions is restricted to a narrow area close to the flame front where these species reach a molecular weight of about 1000 u. Depending on the flame configuration, soot formation is controlled by the coagulation of nanoparticles or by the addition of PAH to soot nuclei. PMID:12718969

  17. Gas Dynamics, Characterization, and Calibration of Fast Flow Flight Cascade Impactor Quartz Crystal Microbalances (QCM) for Aerosol Measurements

    NASA Technical Reports Server (NTRS)

    Grant, J.R.; Thorpe, A. N.; James, C.; Michael, A.; Ware, M.; Senftle, F.; Smith, S.

    1997-01-01

    During recent high altitude flights, we have tested the aerosol section of the fast flow flight cascade impactor quartz crystal microbalance (QCM) on loan to Howard University from NASA. The aerosol mass collected during these flights was disappointingly small. Increasing the flow through the QCM did not correct the problem. It was clear that the instrument was not being operated under proper conditions for aerosol collect ion primarily because the gas dynamics is not well understood. A laboratory study was therefore undertaken using two different fast flow QCM's in an attempt to establish the gas flow characteristics of the aerosol sections and its effect on particle collection, Some tests were made at low temperatures but most of the work reported here was carried out at room temperature. The QCM is a cascade type impactor originally designed by May (1945) and later modified by Anderson (1966) and Mercer et al (1970) for chemical gas analysis. The QCM has been used extensively for collecting and sizing stratospheric aerosol particles. In this paper all flow rates are given or corrected and referred to in terms of air at STP. All of the flow meters were kept at STP. Although there have been several calibration and evaluation studies of moderate flow cascade impactors of less than or equal to 1 L/rein., there is little experimental information on the gas flow characteristics for fast flow rates greater than 1 L/rein.

  18. Secondary organic aerosol formation and primary organic aerosol oxidation from biomass burning smoke in a flow reactor during FLAME-3

    NASA Astrophysics Data System (ADS)

    Ortega, A. M.; Day, D. A.; Cubison, M. J.; Brune, W. H.; Bon, D.; de Gouw, J. A.; Jimenez, J. L.

    2013-05-01

    We report the physical and chemical effects of photochemically aging dilute biomass-burning smoke. A potential aerosol mass "PAM" flow reactor was used with analysis by a high-resolution aerosol mass spectrometer and a proton-transfer reaction ion-trap mass spectrometer during the FLAME-3 campaign. Hydroxyl (OH) radical concentrations in the reactor reached up to ~ 1000 times average tropospheric levels, producing effective OH exposures equivalent to up to 5 days aging in the atmosphere. VOC observations show aromatics and terpenes decrease with aging, while formic acid and other unidentified oxidation products increase. Unidentified gas-phase oxidation products, previously observed in atmospheric and laboratory measurements, were observed here, including evidence of multiple generations of photochemistry. Substantial new organic aerosol (OA) mass ("net SOA"; secondary OA) was observed from aging biomass-burning smoke, resulting in an total OA average of 1.42 ± 0.36 times the initial primary OA (POA) after oxidation. This study confirms that the net SOA to POA ratio of biomass burning smoke is far lower on average than that observed for urban emissions. Although most fuels were very reproducible, significant differences were observed among the biomasses, with some fuels resulting in a doubling of the OA mass, while for others a very small increase or even a decrease was observed. Net SOA formation in the photochemical reactor increased with OH exposure (OHexp), typically peaking around three days of equivalent atmospheric photochemical age (OHexp ~ 3.9 × 1011 molecules cm-3 s-1), then leveling off at higher exposures. The amount of additional OA mass added from aging is positively correlated with initial POA concentration, but not with the total VOC concentration or the concentration of known SOA precursors. The mass of SOA formed often exceeds the mass of the known VOC precursors, indicating the likely importance of primary semivolatile/intermediate volatility

  19. Alveolar targeting of aerosol pentamidine. Toward a rational delivery system

    SciTech Connect

    Simonds, A.K.; Newman, S.P.; Johnson, M.A.; Talaee, N.; Lee, C.A.; Clarke, S.W. )

    1990-04-01

    Nebulizer systems that deposit a high proportion of aerosolized pentamidine on large airways are likely to be associated with marked adverse side effects, which may lead to premature cessation of treatment. We have measured alveolar deposition and large airway-related side effects (e.g., cough, breathlessness, and effect on pulmonary function) after aerosolization of 150 mg pentamidine isethionate labeled with {sup 99m}Tc-Sn-colloid. Nine patients with AIDS were studied using three nebulizer systems producing different droplet size profiles: the Acorn System 22, Respirgard II, and Respirgard II with the inspiratory baffle removed. Alveolar deposition was greatest and side effects least with the nebulizer producing the smallest droplet size profile (Respirgard II), whereas large airway-related side effects were prominent and alveolar deposition lowest with the nebulizer producing the largest droplet size (Acorn System 22). Values for alveolar deposition and adverse airway effects were intermediate using the Respirgard with inspiratory baffle removed, thus indicating the importance of the baffle valve in determining droplet size. Addition of a similar baffle valve to the Acorn System 22 produced a marked improvement in droplet size profile. Selection of a nebulizer that produces an optimal droplet size range offers the advantage of enhancing alveolar targeting of aerosolized pentamidine while reducing large airway-related side effects.

  20. Endovascular blood flow measurement system

    NASA Astrophysics Data System (ADS)

    Khe, A. K.; Cherevko, A. A.; Chupakhin, A. P.; Krivoshapkin, A. L.; Orlov, K. Yu

    2016-06-01

    In this paper an endovascular measurement system used for intraoperative cerebral blood flow monitoring is described. The system is based on a Volcano ComboMap Pressure and Flow System extended with analogue-to-digital converter and PC laptop. A series of measurements performed in patients with cerebrovascular pathologies allows us to introduce “velocity-pressure” and “flow rate-energy flow rate” diagrams as important characteristics of the blood flow. The measurement system presented here can be used as an additional instrument in neurosurgery for assessment and monitoring of the operation procedure. Clinical data obtained with the system are used for construction of mathematical models and patient-specific simulations. The monitoring of the blood flow parameters during endovascular interventions was approved by the Ethics Committee at the Meshalkin Novosibirsk Research Institute of Circulation Pathology and included in certain surgical protocols for pre-, intra- and postoperative examinations.

  1. Atmospheric pressure flow reactor / aerosol mass spectrometer studies of tropospheric aerosol nucleat and growth kinetics. Final report, June, 2001

    SciTech Connect

    Worsnop, Douglas R.

    2001-06-01

    The objective of this program was to determine the mechanisms and rates of growth and transformation and growth processes that control secondary aerosol particles in both the clear and polluted troposphere. The experimental plan coupled an aerosol mass spectrometer (AMS) with a chemical ionization mass spectrometer to provide simultaneous measurement of condensed and particle phases. The first task investigated the kinetics of tropospheric particle growth and transformation by measuring vapor accretion to particles (uptake coefficients, including mass accommodation coefficients and heterogeneous reaction rate coefficients). Other work initiated investigation of aerosol nucleation processes by monitoring the appearance of submicron particles with the AMS as a function of precursor gas concentrations. Three projects were investigated during the program: (1) Ozonolysis of oleic acid aerosols as model of chemical reactivity of secondary organic aerosol; (2) Activation of soot particles by measurement deliquescence in the presence of sulfuric acid and water vapor; (3) Controlled nucleation and growth of sulfuric acid aerosols.

  2. Aerosolization of lipoplexes using AERx Pulmonary Delivery System.

    PubMed

    Deshpande, Deepa; Blanchard, James; Srinivasan, Sudarshan; Fairbanks, Dallas; Fujimoto, Jun; Sawa, Teiji; Wiener-Kronish, Jeanine; Schreier, Hans; Gonda, Igor

    2002-01-01

    The lung represents an attractive target for delivering gene therapy to achieve local and potentially systemic delivery of gene products. The objective of this study was to evaluate the feasibility of the AERx Pulmonary Delivery System for delivering nonviral gene therapy formulations to the lung. We found that "naked" DNA undergoes degradation following aerosolization through the AERx nozzle system. However, DNA formulated with a molar excess of cationic lipids (lipoplexes) showed no loss of integrity. In addition, the lipoplexes showed no significant change in particle size, zeta (zeta) potential, or degree of complexation following extrusion. The data suggest that complexation with cationic lipids had a protective effect on the formulation following extrusion. In addition, there was no significant change in the potency of the formulation as determined by a transfection study in A-549 cells in culture. We also found that DNA formulations prepared in lactose were aerosolized poorly. Significant improvements in aerosolization efficiency were seen when electrolytes such as NaCl were added to the formulation. In conclusion, the data suggest that delivery of lipoplexes using the AERx Pulmonary Delivery System may be a viable approach for pulmonary gene therapy. PMID:12423062

  3. A Search for Correlations Between Four Different Atmospheric Aerosol Measurement Systems Atop Rattlesnake Mountain, Washington

    NASA Astrophysics Data System (ADS)

    Milbrath, Brian

    2004-05-01

    Accurate atmospheric aerosol transport measurements are important to international nuclear test monitoring, emergency response, health and ecosystem toxicology, and climate change. An International Monitoring System (IMS) is being established which will include a suite of aerosol radionuclide sensors. To explore the possibility of using the IMS sites to improve the understanding of global atmospheric aerosol transport, four state-of-the-art aerosol measurement systems were placed atop Rattlesnake Mountain at Pacific Northwest National Laboratory. The Radionuclide Aerosol Sampler/Analyzer measures radionuclide concentration via gamma-ray spectroscopy. The Cascade Impactor Beam Analyzer Technique measures 30 elements in three aerosol sizes using PNNLâ's Ion Beams Materials Analysis Laboratory. The Tapered Element Oscillating Microbalance provides time-averaged aerosol mass concentrations for a range of sizes. The Multi-Filter Rotating Shadowband Radiometer measures the solar irradiance to derive an aerosol optical depth. Results and correlations from the four different detectors will be presented.

  4. New apparatus of single particle trap system for aerosol visualization

    NASA Astrophysics Data System (ADS)

    Higashi, Hidenori; Fujioka, Tomomi; Endo, Tetsuo; Kitayama, Chiho; Seto, Takafumi; Otani, Yoshio

    2014-08-01

    Control of transport and deposition of charged aerosol particles is important in various manufacturing processes. Aerosol visualization is an effective method to directly observe light scattering signal from laser-irradiated single aerosol particle trapped in a visualization cell. New single particle trap system triggered by light scattering pulse signal was developed in this study. The performance of the device was evaluated experimentally. Experimental setup consisted of an aerosol generator, a differential mobility analyzer (DMA), an optical particle counter (OPC) and the single particle trap system. Polystylene latex standard (PSL) particles (0.5, 1.0 and 2.0 μm) were generated and classified according to the charge by the DMA. Singly charged 0.5 and 1.0 μm particles and doubly charged 2.0 μm particles were used as test particles. The single particle trap system was composed of a light scattering signal detector and a visualization cell. When the particle passed through the detector, trigger signal with a given delay time sent to the solenoid valves upstream and downstream of the visualization cell for trapping the particle in the visualization cell. The motion of particle in the visualization cell was monitored by CCD camera and the gravitational settling velocity and the electrostatic migration velocity were measured from the video image. The aerodynamic diameter obtained from the settling velocity was in good agreement with Stokes diameter calculated from the electrostatic migration velocity for individual particles. It was also found that the aerodynamic diameter obtained from the settling velocity was a one-to-one function of the scattered light intensity of individual particles. The applicability of this system will be discussed.

  5. A portable optical particle counter system for measuring dust aerosols.

    PubMed

    Marple, V A; Rubow, K L

    1978-03-01

    A portable battery-operated optical particle counter/multichannel analyzer system has been developed for the numbers size distribution and number concentration measurement of light-absorbing irregular-shaped dust particles. An inertial impactor technique has been used to obtain calibration curves by relating the magnitude of the optical counter's signal to the particle's aerodynamic or Stokes' diameter. These calibrations have been made for aerosols of coal, potash, silica, rock (copper ore), and Arizona road dust particles. PMID:645547

  6. Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

    SciTech Connect

    Moore, Murray E.

    2015-02-23

    Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to mass flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is

  7. Determination of Maintaining Time of Temperature Traces of Aerosol Droplet Water Flows During Motion in a Flame

    NASA Astrophysics Data System (ADS)

    Antonov, D. V.; Voitkov, I. S.; Strizhak, P. A.

    2016-02-01

    To develop fire fighting technologies, the temperatures of combustible products were measured after passing an aerosol droplet flow of water through the flames (with monitored temperatures). It was applied the aerosol flows with droplets of sizes less than 100 μm, 100-200 μm, and 200-300 μm. Investigations were conducted at a temperature of combustible products from 500 K to 900 K. Temperatures of gases in droplet flow traces and maintaining times of relatively low temperatures in these areas (it can be considered as temperature trace) were defined. It was obtained the satisfactory agreement of experimental results and numerical simulation data.

  8. Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems.

    PubMed

    Benami, Maya; Busgang, Allison; Gillor, Osnat; Gross, Amit

    2016-08-15

    Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) - a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus. According to the settle-plate technique, low amounts (0-9.7×10(4)CFUm(-2)h(-1)) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1m away from the GW systems. At the 5m distance amounts of these bacteria were not statistically different (p>0.05) from background concentrations tested over 50m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques to provide more accurate

  9. AEROFROSH: a shock condition calculator for multi-component fuel aerosol-laden flows

    NASA Astrophysics Data System (ADS)

    Campbell, M. F.; Haylett, D. R.; Davidson, D. F.; Hanson, R. K.

    2015-08-01

    This article introduces an algorithm that determines the thermodynamic conditions behind incident and reflected shocks in aerosol-laden flows. Importantly, the algorithm accounts for the effects of droplet evaporation on post-shock properties. Additionally, this article describes an algorithm for resolving the effects of multiple-component-fuel droplets. This article presents the solution methodology and compares the results to those of another similar shock calculator. It also provides examples to show the impact of droplets on post-shock properties and the impact that multi-component fuel droplets have on shock experimental parameters. Finally, this paper presents a detailed uncertainty analysis of this algorithm's calculations given typical experimental uncertainties.

  10. FLOW SYSTEM FOR REACTOR

    DOEpatents

    Zinn, W.H.

    1963-06-11

    A reactor is designed with means for terminating the reaction when returning coolant is below a predetermined temperature. Coolant flowing from the reactor passes through a heat exchanger to a lower reservoir, and then circulates between the lower reservoir and an upper reservoir before being returned to the reactor. Means responsive to the temperature of the coolant in the return conduit terminate the chain reaction when the temperature reaches a predetermined minimum value. (AEC)

  11. Systems engineering tradeoffs for a bio-aerosol lidar referee system

    NASA Astrophysics Data System (ADS)

    Warren, Jeffery W.; Thomas, Michael E.; Rogala, Eric W.; Maret, Arthur R.; Schumacher, Camille A.; Diaz, Antonio

    2004-08-01

    Analytical results and tradeoffs are reported for an aerosol lidar system that is intended to serve as a referee during testing of standoff bio-aerosol detection systems. The lidar system is still under development by Dugway Proving Grounds -- results from the operational system are not included in this paper. The recommended configuration of the lidar system is to use a 1064 nm lidar in elastic mode to measure the concentration of the aerosol, and a 355 nm excitation to measure the fluorescence of the bio-aerosol. Both of these measurements are important in scoring the performance of the systems that will be tested at DPG. Performance tradeoffs and predictions are presented primarily for the elastic mode lidar. The elastic mode lidar is designed to make measurements out to ranges of approximately 15 km. The UV fluorescence mode of operation is intended to support discrimination of bio-aerosols from non-biological aerosols, and is only required to operate at a range of 1 km. The optical design of the proposed telescope supports dual wavelength operation, allows for effective TV camera imaging for test and alignment support, and tailors the optical overlap function for the UV and near IR lidar to optimize the performance of both subsystems.

  12. Measurements of Atmospheric Aerosol Vertical Distributions above Svalbard, Norway using Unmanned Aerial Systems (UAS)

    NASA Astrophysics Data System (ADS)

    Bates, T. S.; Johnson, J. E.; Stalin, S.; Telg, H.; Murphy, D. M.; Burkhart, J. F.; Quinn, P.; Storvold, R.

    2015-12-01

    Atmospheric aerosol vertical distributions were measured above Svalbard, Norway in April 2015 to investigate the processes controlling aerosol concentrations and radiative effects. The aerosol payload was flown in a NOAA/PMEL MANTA Unmanned Aerial System (UAS) on 9 flights totaling 19 flight hours. Measurements were made of particle number concentration and aerosol light absorption at three wavelengths, similar to those conducted in April 2011 (Bates et al., Atmos. Meas. Tech., 6, 2115-2120, 2013). A filter sample was collected on each flight for analyses of trace elements. Additional measurements in the aerosol payload in 2015 included aerosol size distributions obtained using a Printed Optical Particle Spectrometer (POPS) and aerosol optical depth obtained using a four wavelength miniature Scanning Aerosol Sun Photometer (miniSASP). The data show most of the column aerosol mass and resulting optical depth in the boundary layer but frequent aerosol layers aloft with high particle number concentration (2000 cm-3) and enhanced aerosol light absorption (1 Mm-1). Transport of these aerosol layers was assessed using FLEXPART particle dispersion models. The data contribute to an assessment of sources of BC to the Arctic and potential climate impacts.

  13. Direct flow crystal growth system

    DOEpatents

    Montgomery, Kenneth E.; Milanovich, Fred P.

    1992-01-01

    A crystal is grown in a constantly filtered solution which is flowed directly into the growing face of a crystal. In a continuous flow system, solution at its saturation temperature is removed from a crystal growth tank, heated above its saturation temperature, filtered, cooled back to its saturation temperature, and returned to the tank.

  14. Effects of aerosol on evaporation, freezing and precipitation in a multiple cloud system

    NASA Astrophysics Data System (ADS)

    Lee, Seoung Soo; Kim, Byung-Gon; Yum, Seong Soo; Seo, Kyong-Hwan; Jung, Chang-Hoon; Um, Jun Shik; Li, Zhanqing; Hong, JinKyu; Chang, Ki-Ho; Jeong, Jin-Yim

    2016-04-01

    Aerosol effects on clouds and precipitation account for a large portion of uncertainties in the prediction of the future course of global hydrologic circulations and climate. As a process of a better understanding of interactions between aerosol, clouds and precipitation, simulations are performed for a mixed-phase convective multiple-cloud system over the tropics. Studies on single-cloud systems have shown that aerosol-induced increases in freezing, associated increases in parcel buoyancy and thus the intensity of clouds (or updrafts) are a main mechanism which controls aerosol-cloud-precipitation interactions in convective clouds. However, in the multiple-cloud system that plays much more important roles in global hydrologic circulations and thus climate than single-cloud systems, aerosol effects on condensation play the most important role in aerosol-induced changes in the intensity of clouds and the effects on freezing play a negligible role in those changes. Aerosol-induced enhancement in evaporation intensifies gust fronts and increases the number of subsequently developing clouds, which leads to the substantial increases in condensation and associated intensity of convection. Although aerosol-induced enhancement in freezing takes part in the increases in condensation by inducing stronger convergence around cloud bottom, the increases in condensation are ~one order of magnitude larger than those in freezing. It is found that while aerosol-induced increases in freezing create intermittent extremely heavy precipitation, aerosol-induced increases in evaporation enhance light and medium precipitation in the multiple-cloud system here. This increase in light and medium precipitation makes it possible that cumulative precipitation increases with increasing aerosol concentration, although the increase is small. It is interesting that the altitude of the maximum of the time- and domain-averaged hydrometeor mass densities is quite robust to increases in aerosol

  15. Aerosol observing system platform integration and AAF instrumentation

    SciTech Connect

    Springston, S.; Sedlacek, A.

    2010-03-15

    As part of the federal government’s 2009 American Recovery and Reinvestment Act (ARRA), the U.S. DOE Office of Science allocated funds for the capital upgrade of the Atmospheric Radiation Measurement (ARM) Climate Research Facility to improve and expand observational capabilities related to cloud and aerosol properties. The ARM Facility was established as a national user facility for the global scientific community to conduct a wide range of interdisciplinary science. Part of the ARRA-funded expansion of the ARM Facility includes four new Aerosol Observing Systems (AOS) to be designed, instrumented, and mentored by BNL. The enclosures will be customized SeaTainers. These new platforms ([AMF2]: ARM Mobile Facility-2; [TWP-D]: Tropical Western Pacific at Darwin; and [MAOS-A]/[MAOS-C]: Mobile Aerosol Observing System-Aerosol/-Chemistry) will provide a laboratory environment for fielding instruments to collect data on aerosol life cycle, microphysics, and optical/physical properties. The extensive instrument suite includes both established methods and initial deployments of new techniques to add breadth and depth to the AOS data sets. The platforms are designed: (1) to have all instruments pre-installed before deployment, allowing a higher measurement duty cycle; (2) with a standardized configuration improving the robustness of data inter-comparability; (3) to provide remote access capability for instrument mentors; and (4) to readily accommodate guest instrumentation. The first deployment of the AMF2 platform will be at the upcoming StormVEx campaign held at Steamboat Springs, Colorado, October 15, 2010–March 31, 2011 while the TWP-D AOS will be stationed at the ARM Darwin site. The maiden deployments of the MAOS-A and MAOS-C platforms will be during the Ganges Valley Experiment (GVAX) scheduled for April 2011–April 2012. In addition to the ground-based AOS platforms, thee major instrument builds for the AAF are also being undertaken (new trace gas package [NO

  16. Flow analysis system and method

    NASA Technical Reports Server (NTRS)

    Hill, Wayne S. (Inventor); Barck, Bruce N. (Inventor)

    1998-01-01

    A non-invasive flow analysis system and method wherein a sensor, such as an acoustic sensor, is coupled to a conduit for transmitting a signal which varies depending on the characteristics of the flow in the conduit. The signal is amplified and there is a filter, responsive to the sensor signal, and tuned to pass a narrow band of frequencies proximate the resonant frequency of the sensor. A demodulator generates an amplitude envelope of the filtered signal and a number of flow indicator quantities are calculated based on variations in amplitude of the amplitude envelope. A neural network, or its equivalent, is then used to determine the flow rate of the flow in the conduit based on the flow indicator quantities.

  17. Miniaturized flow injection analysis system

    DOEpatents

    Folta, J.A.

    1997-07-01

    A chemical analysis technique known as flow injection analysis is described, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38{times}25{times}3 mm, but can be designed for gas analysis and be substantially smaller in construction. 9 figs.

  18. Miniaturized flow injection analysis system

    DOEpatents

    Folta, James A.

    1997-01-01

    A chemical analysis technique known as flow injection analysis, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38.times.25.times.3 mm, but can be designed for gas analysis and be substantially smaller in construction.

  19. The Multi-Sensor Aerosol Products Sampling System (MAPSS) for Integrated Analysis of Satellite Retrieval Uncertainties

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles; Petrenko, Maksym; Leptoukh, Gregory

    2010-01-01

    Among the known atmospheric constituents, aerosols represent the greatest uncertainty in climate research. Although satellite-based aerosol retrieval has practically become routine, especially during the last decade, there is often disagreement between similar aerosol parameters retrieved from different sensors, leaving users confused as to which sensors to trust for answering important science questions about the distribution, properties, and impacts of aerosols. As long as there is no consensus and the inconsistencies are not well characterized and understood ', there will be no way of developing reliable climate data records from satellite aerosol measurements. Fortunately, the most globally representative well-calibrated ground-based aerosol measurements corresponding to the satellite-retrieved products are available from the Aerosol Robotic Network (AERONET). To adequately utilize the advantages offered by this vital resource,., an online Multi-sensor Aerosol Products Sampling System (MAPSS) was recently developed. The aim of MAPSS is to facilitate detailed comparative analysis of satellite aerosol measurements from different sensors (Terra-MODIS, Aqua-MODIS, Terra-MISR, Aura-OMI, Parasol-POLDER, and Calipso-CALIOP) based on the collocation of these data products over AERONET stations. In this presentation, we will describe the strategy of the MAPSS system, its potential advantages for the aerosol community, and the preliminary results of an integrated comparative uncertainty analysis of aerosol products from multiple satellite sensors.

  20. Influence of flow rate on aerosol particle size distributions from pressurized and breath-actuated inhalers.

    PubMed

    Smith, K J; Chan, H K; Brown, K F

    1998-01-01

    Particle size distribution of delivered aerosols and the total mass of drug delivered from the inhaler are important determinants of pulmonary deposition and response to inhalation therapy. Inhalation flow rate may vary between patients and from dose to dose. The Andersen Sampler (AS) cascade impactor operated at flow rates of 30 and 55 L/min and the Marple-Miller Impactor (MMI) operated at flow rates of 30, 55, and 80 L/min were used in this study to investigate the influence of airflow rate on the particle size distributions of inhalation products. Total mass of drug delivered from the inhaler, fine particle mass, fine particle fraction, percentage of nonrespirable particles, and amount of formulation retained within the inhaler were determined by ultraviolet spectrophotometry for several commercial bronchodilator products purchased in the marketplace, including a pressurized metered-dose inhaler (pMDI), breath-actuated pressurized inhaler (BAMDI), and three dry powder inhalers (DPIs), two containing salbutamol sulphate and the other containing terbutaline sulphate. Varying the flow rate through the cascade impactor produced no significant change in performance of the pressurized inhalers. Increasing the flow rate produced a greater mass of drug delivered and an increase in respirable particle mass and fraction from all DPIs tested. PMID:10346666

  1. Halogen-induced organic aerosol (XOA) formation and decarboxylation of carboxylic acids by reactive halogen species - a time-resolved aerosol flow-reactor study

    NASA Astrophysics Data System (ADS)

    Ofner, Johannes; Zetzsch, Cornelius

    2013-04-01

    Reactive halogen species (RHS) are released to the atmosphere from various sources like photo-activated sea-salt aerosol and salt lakes. Recent studies (Cai et al., 2006 and 2008, Ofner et al., 2012) indicate that RHS are able to interact with SOA precursors similarly to common atmospheric oxidizing gases like OH radicals and ozone. The reaction of RHS with SOA precursors like terpenes forms so-called halogen-induced organic aerosol (XOA). On the other hand, RHS are also able to change the composition of functional groups, e.g. to initiate the decarboxylation of carboxylic acids (Ofner et al., 2012). The present study uses a 50 cm aerosol flow-reactor, equipped with a solar simulator to investigate the time-resolved evolution and transformation of vibrational features in the mid-infrared region. The aerosol flow-reactor is coupled to a home-made multi-reflection cell (Ofner et al., 2010), integrated into a Bruker IFS 113v FTIR spectrometer. The reactor is operated with an inlet feed (organic compound) and a surrounding feed (reactive halogen species). The moveable inlet of the flow reactor allows us to vary reaction times between a few seconds and up to about 3 minutes. Saturated vapours of different SOA precursors and carboxylic acids were fed into the flow reactor using the moveable inlet. The surrounding feed inside the flow reactor was a mixture of zero air with molecular chlorine as the precursor for the formation of reactive halogen species. Using this setup, the formation of halogen-induced organic aerosol could be monitored with a high time resolution using FTIR spectroscopy. XOA formation is characterized by hydrogen-atom abstraction, carbon-chlorine bond formation and later, even formation of carboxylic acids. Several changes of the entire structure of the organic precursor, caused by the reaction of RHS, are visible. While XOA formation is a very fast process, the decarboxylation of carboxylic acids, induced by RHS is rather slow. However, XOA formation

  2. Data-driven aerosol development in the GEOS-5 modeling and data assimilation system

    NASA Astrophysics Data System (ADS)

    Darmenov, A.; da Silva, A.; Liu, X.; Colarco, P. R.

    2013-12-01

    Atmospheric aerosols are important radiatively active agents that also affect clouds, atmospheric chemistry, the water cycle, land and ocean biogeochemistry. Furthermore, exposure to anthropogenic and/or natural fine particulates can have negative health effects. No single instrument or model is capable of quantifying the diverse and dynamic nature of aerosols at the range of spatial and temporal scales at which they interact with the other constituents and components of the Earth system. However, applying model-data integration techniques can minimize limitations of individual data products and remedy model deficiencies. The Goddard Earth Observing System Model, Version 5 (GEOS-5) is the latest version of the NASA Global Modeling and Assimilation Office (GMAO) Earth system model. GEOS-5 is a modeling and data assimilation framework well suited for aerosol research. It is being used to perform aerosol re-analysis and near real-time aerosol forecast on a global scale at resolutions comparable to those of aerosol products from modern spaceborne instruments. The aerosol processes in GEOS-5 derive from the Goddard Chemistry Aerosol Radiation and Transport (GOCART) but it is implemented on-line, within the climate model. GEOS-5 aerosol modeling capabilities have recently been enhanced by inclusion of the Modal Aerosol Microphysics module (MAM-7) originally developed in the Community Earth System Model (CESM) model. This work will present examples of data driven model development that include refining parameterization of sea-salt emissions, tuning of biomass burning emissions from vegetation fires and the effect of the updated emissions on the modeled direct aerosol forcing. We will also present results from GOES-5/MAM-7 model evaluation against AOD and particulate pollution datasets, and outline future directions of aerosol data assimilation in the GEOS-5 system.

  3. Non-spherical aerosol transport under oscillatory shear flows at low-Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Shachar Berman, Lihi; Delorme, Yann; Hofemeier, Philipp; Frankel, Steven; Sznitman, Josue

    2014-11-01

    Most airborne particles are intrinsically non-spherical. In particular, non-spherical particles with high aspect ratios, such as fibers, are acknowledged to be more hazardous than their spherical counterparts due to their ability to penetrate into deeper lung regions, causing serious pulmonary diseases. Not only do particle properties such as size, shape, and density have a major impact on particle transport, for non-spherical aerosols, their orientations also greatly influence particle trajectories due to modified lift and drag characteristics. Until present, however, most of our understanding of the dynamics of inhaled particles in the deep airways of the lungs has been limited to spherical particles only. In the present work, we seek to quantify through numerical simulations the transport of non-spherical airborne particles and their deposition under oscillatory shear flows at low Reynolds numbers, characteristic of acinar airways. Here, the Euler-Lagrangian model is used to solve the translational movement of a fiber, whereas the Eulerian rotational equations are introduced and solved to predict detailed unsteady fiber orientations. Overall, our efforts provide new insight into realistic dynamics of inhaled non-spherical aerosols under characteristic breathing motions.

  4. Quantifying the Reactive Uptake of OH by Organic Aerosols in aContinuous Flow Stirred Tank Reactor

    SciTech Connect

    Che, Dung L.; Smith, Jared D.; Leone, Stephen R.; Ahmed, Musahid; Wilson, Kevin R.

    2009-03-01

    Here we report a new method for measuring the heterogeneous chemistry of submicron organic aerosol particles using a continuous flow stirred tank reactor. This approach is designed to quantify the real time heterogeneous kinetics, using a relative rate method, under conditions of low oxidant concentration and long reaction times that more closely mimic the real atmosphere. A general analytical expression, which couples the aerosol chemistry with the flow dynamics in the chamber is developed and applied to the heterogeneous oxidation of squalane particles by hydroxyl radicals (OH) in the presence of O2. The particle phase reaction is monitored via photoionization aerosol mass spectrometry and yields a reactive uptake coefficient of 0.51+-0.10, using OH concentrations of 1-7x108 molec cdot cm-3 and reaction times of 1.5+-3 hours. This uptake coefficient is larger than that found for the reaction carried out under high OH concentrations (~;;1x1010 molec cdot cm-3) and short reaction times in a flow tube reactor. This difference suggests that oxidant concentration and reaction time are not interchangeable quantities in reactions of organic aerosols with radicals. In general, this approach provides a new way to examine how the chemical aging of organic particles measured at short reaction times and high oxidant concentrations in flow tubes might differ from the long reaction times and low oxidant levels found in the real atmosphere.

  5. BEHAVIOR OF CONSTANT RATE AEROSOL REACTORS (JOURNAL VERSION)

    EPA Science Inventory

    An aerosol reactor is a gaseous system in which fine particles are formed by chemical reaction in either a batch or flow process. Such reactors are used to study the aerosol formation process, as in a smog reactor, or to generate a product such as a pigment or a catalytic aerosol...

  6. New capabilities for space-based cloud and aerosols measurements: The Cloud-Aerosol Transport System (CATS)

    NASA Astrophysics Data System (ADS)

    Yorks, J. E.; McGill, M. J.; Hlavka, D. L.; Palm, S. P.; Hart, W. D.; Nowottnick, E. P.; Vaughan, M.; Rodier, S. D.; Colarco, P. R.; da Silva, A.; Buchard-Marchant, V.

    2013-12-01

    Current uncertainties in cloud and aerosol properties limit our ability to accurately model the Earth's climate system and predict climate change. These limitations are due primarily to difficulties in adequately measuring aerosols and clouds on a global scale. NASA's A-Train satellites provide an unprecedented opportunity to address these uncertainties. In particular, the Cloud-Aerosol Lidar Infrared Pathfinder Spaceborne Observations (CALIPSO) satellite provides vertical profiles of cloud and aerosol properties. The CALIOP lidar onboard CALIPSO has reached its seventh year of operation, well past its expected lifetime. The ATLID lidar on EarthCARE is not expected to launch until 2016 or later. If the CALIOP lidar fails before a new mission is operational, there will be a gap in global lidar measurements. The Cloud-Aerosol Transport System (CATS), built at NASA Goddard Space Flight Center as a payload for the International Space Station (ISS), is set to launch in the summer of 2014. CATS is an elastic backscatter lidar with three wavelengths (1064, 532, 355 nm) and HSRL capability at 532 nm. Depolarization measurements will be made at all three wavelengths. The ISS orbit is a 51 degree inclination orbit at an altitude of about 405 km. This orbit provides more comprehensive coverage of the tropics and mid-latitudes than sun-synchronous orbiting sensors, with nearly a three day repeat cycle. Thus, science applications of CATS include cloud and aerosol climate studies, air quality monitoring, and smoke/volcanic plume tracking. The primary science objectives of CATS include: continuing the CALIPSO aerosol and cloud vertical profile data record, providing near real time data to support operational applications such as air quality modeling, and advancing technology in support of future mission development using the HSRL channel. Furthermore, the vertical profiles of cloud and aerosol properties provided by CATS will complement current and future passive satellite

  7. SECONDARY ORGANIC AEROSOL FORMATION FROM THE OXIDATION OF AROMATIC HYDROCARBONS IN THE PRESENCE OF DRY SUBMICRON AMMONIUM SULFATE AEROSOL

    EPA Science Inventory

    A laboratory study was conducted to examine formation of secondary organic aerosols. A smog chamber system was developed for studying gas-aerosol interactions in a dynamic flow reactor. These experiments were conducted to investigate the fate of gas and aerosol phase compounds ...

  8. Measurements of atmospheric aerosol vertical distributions above Svalbard, Norway, using unmanned aerial systems (UAS)

    NASA Astrophysics Data System (ADS)

    Bates, T. S.; Quinn, P. K.; Johnson, J. E.; Corless, A.; Brechtel, F. J.; Stalin, S. E.; Meinig, C.; Burkhart, J. F.

    2013-08-01

    Atmospheric aerosol vertical distributions were measured above Svalbard, Norway, in April 2011 during the Cooperative Investigation of Climate-Cryosphere Interactions campaign (CICCI). Measurements were made of the particle number concentration and the aerosol light absorption coefficient at three wavelengths. A filter sample was collected on each flight at the altitude of maximum particle number concentration. The filters were analyzed for major anions and cations. The aerosol payload was flown in a NOAA/PMEL MANTA Unmanned Aerial System (UAS). A total of 18 flights were flown during the campaign totaling 38 flight hours. The data show frequent aerosol layers aloft with high particle number concentration (1000 cm-3) and enhanced aerosol light absorption (1 Mm-1). Air mass histories of these aerosol layers were assessed using FLEXPART particle dispersion modeling. The data contribute to an assessment of sources of BC to the Arctic and potential climate impacts.

  9. Measurements of atmospheric aerosol vertical distributions above Svalbard, Norway using unmanned aerial systems (UAS)

    NASA Astrophysics Data System (ADS)

    Bates, T. S.; Quinn, P. K.; Johnson, J. E.; Corless, A.; Brechtel, F. J.; Stalin, S. E.; Meinig, C.; Burkhart, J. F.

    2013-03-01

    Atmospheric aerosol vertical distributions were measured above Svalbard, Norway in April 2011 during the Cooperative Investigation of Climate-Cryosphere Interactions campaign (CICCI). Measurements were made of the particle number concentration and the aerosol light absorption coefficient at three wavelengths. A filter sample was collected on each flight at the altitude of maximum particle number concentration. The filters were analyzed for major anions and cations. The aerosol payload was flown in a NOAA/PMEL MANTA Unmanned Aerial System (UAS). A total of 18 flights were flown during the campaign totaling 38 flight hours. The data show frequent aerosol layers aloft with high particle number concentration (1000 cm-3 and enhanced aerosol light absorption (1 Mm-1). Air mass histories of these aerosol layers were assessed using FLEXPART particle dispersion modeling. The data contribute to an assessment of sources of BC to the Arctic and potential climate impacts.

  10. Real-time analysis of ambient organic aerosols using aerosol flowing atmospheric-pressure afterglow mass spectrometry (AeroFAPA-MS)

    NASA Astrophysics Data System (ADS)

    Brüggemann, Martin; Karu, Einar; Stelzer, Torsten; Hoffmann, Thorsten

    2015-04-01

    Organic aerosol accounts for a major fraction of atmospheric aerosols and has implications on the earth's climate and human health. However, due to the chemical complexity its measurement remains a major challenge for analytical instrumentation.1 Here, we present the development, characterization and application of a new soft ionization technique that allows mass spectrometric real-time detection of organic compounds in ambient aerosols. The aerosol flowing atmospheric-pressure afterglow (AeroFAPA) ion source utilizes a helium glow discharge plasma to produce excited helium species and primary reagent ions. Ionization of the analytes occurs in the afterglow region after thermal desorption and results mainly in intact molecular ions, facilitating the interpretation of the acquired mass spectra. In the past, similar approaches were used to detect pesticides, explosives or illicit drugs on a variety of surfaces.2,3 In contrast, the AeroFAPA source operates 'online' and allows the detection of organic compounds in aerosols without a prior precipitation or sampling step. To our knowledge, this is the first application of an atmospheric-pressure glow discharge ionization technique to ambient aerosol samples. We illustrate that changes in aerosol composition and concentration are detected on the time scale of seconds and in the ng-m-3 range. Additionally, the successful application of AeroFAPA-MS during a field study in a mixed forest region in Central Europe is presented. Several oxidation products of monoterpenes were clearly identified using the possibility to perform tandem MS experiments. The acquired data are in agreement with previous studies and demonstrate that AeroFAPA-MS is a suitable tool for organic aerosol analysis. Furthermore, these results reveal the potential of this technique to enable new insights into aerosol formation, growth and transformation in the atmosphere. References: 1) IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The

  11. Pulse-Flow Microencapsulation System

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.

    2006-01-01

    The pulse-flow microencapsulation system (PFMS) is an automated system that continuously produces a stream of liquid-filled microcapsules for delivery of therapeutic agents to target tissues. Prior microencapsulation systems have relied on batch processes that involve transfer of batches between different apparatuses for different stages of production followed by sampling for acquisition of quality-control data, including measurements of size. In contrast, the PFMS is a single, microprocessor-controlled system that performs all processing steps, including acquisition of quality-control data. The quality-control data can be used as real-time feedback to ensure the production of large quantities of uniform microcapsules.

  12. Aerosol deposition in the human respiratory system. Final report

    SciTech Connect

    Yu, C.P.

    1988-01-01

    Attempts were made to develop mathematical models for the deposition of aerosols in the human respiratory system. Expressions were obtained for the mean deposition efficiency for nasal inspiration, nasal expiration, and mouth inspiration. A determination was made of statistical properties associated with each deposition efficiency due to intersubject and intrasubject variabilities. Expressions were then derived for head deposition with combined nose and mouth breathing. In the lung, deposition is a result primarily of impaction, sedimentation, and diffusion. While there was no adequate model for impaction, several deposition formulae for sedimentation were derived as well as ones for diffusion. Studies were also made of the particle charge effect, as the electrostatic image force on a particle contributes to its deposition. There is, however, a threshold charge per particle below which the particle charge has no effect on deposition. Deposition data on ultrafine particles is scarce due to the difficulties in conducting proper experiments.

  13. Effects of aerosols on clear-sky solar radiation in the ALADIN-HIRLAM NWP system

    NASA Astrophysics Data System (ADS)

    Gleeson, Emily; Toll, Velle; Pagh Nielsen, Kristian; Rontu, Laura; Masek, Jan

    2016-05-01

    The direct shortwave radiative effect of aerosols under clear-sky conditions in the Aire Limitee Adaptation dynamique Developpement InterNational - High Resolution Limited Area Model (ALADIN-HIRLAM) numerical weather prediction system was investigated using three shortwave radiation schemes in diagnostic single-column experiments: the Integrated Forecast System (IFS), acraneb2 and the hlradia radiation schemes. The multi-band IFS scheme was formerly used operationally by the European Centre for Medium Range Weather Forecasts (ECMWF) whereas hlradia and acraneb2 are broadband schemes. The former is a new version of the HIRLAM radiation scheme while acraneb2 is the radiation scheme in the ALARO-1 physics package. The aim was to evaluate the strengths and weaknesses of the numerical weather prediction (NWP) system regarding aerosols and to prepare it for use of real-time aerosol information. The experiments were run with particular focus on the August 2010 Russian wildfire case. Each of the three radiation schemes accurately (within ±4 % at midday) simulates the direct shortwave aerosol effect when observed aerosol optical properties are used. When the aerosols were excluded from the simulations, errors of more than +15 % in global shortwave irradiance were found at midday, with the error reduced to +10 % when standard climatological aerosols were used. An error of -11 % was seen at midday if only observed aerosol optical depths at 550 nm, and not observation-based spectral dependence of aerosol optical depth, single scattering albedos and asymmetry factors, were included in the simulations. This demonstrates the importance of using the correct aerosol optical properties. The dependency of the direct radiative effect of aerosols on relative humidity was tested and shown to be within ±6 % in this case. By modifying the assumptions about the shape of the IFS climatological vertical aerosol profile, the inherent uncertainties associated with assuming fixed vertical

  14. Photoacoustic sensor system for the quantification of soot aerosols (abstract)

    NASA Astrophysics Data System (ADS)

    Haisch, C.; Beck, H.; Niessner, R.

    2003-01-01

    The influence of soot particles on human health as well as global and local climate is well established by now. Hence, the need for fast and sensitive soot detection in urban and remote areas is obvious. The state of the art thermochemical detection methods for soot analysis is based on filter sampling and subsequent wet chemical analysis and combustion, which requires laborious and time consuming sample preparation. Due to the integration on a filter, a time-resolved analysis is not possible. The presented photoacoustic sensor system is optimized for a highly sensitive and fast on-line and in situ quantification of soot. Soot particles, as classical "black absorbers," absorb electromagnetic radiation over the whole spectrum. Two similar systems are introduced. The first system is designed for the development and testing of combustion engines, mainly the next generation of diesel engines. In the next decade, legal thresholds for extremely low particle emissions are foreseen. Their implementation will be only possible if a time-resolved soot detection with sufficient sensitivity can be realized as the highest particle emissions from diesel engines are generated only for seconds during load changes. During a load change, the emitted soot concentrations can rise several orders of magnitude for only a period of few seconds. The system combines a time resolution of 1 s (sampling rate 1 Hz) with an aerosol mass sensitivity better than 10 μg m-3. Up to a maximum dimension of about 800 nm the signal is independent of the particle size. The systems consist of two photoacoustic cells, which are operated in a differential mode to avoid cross sensitivities. The cells are built as acoustical resonators to increase sensitivity. A diode laser with a wavelength of 810 nm and an output power of 1.1 W is employed for excitation. Its collimated beam passes first through the reference cell and then through the measurement cell. To avoid condensation of water, the cells are heated to

  15. A Miniature System for Separating Aerosol Particles and Measuring Mass Concentrations

    PubMed Central

    Liang, Dao; Shih, Wen-Pin; Chen, Chuin-Shan; Dai, Chi-An

    2010-01-01

    We designed and fabricated a new sensing system which consists of two virtual impactors and two quartz-crystal microbalance (QCM) sensors for measuring particle mass concentration and size distribution. The virtual impactors utilized different inertial forces of particles in air flow to classify different particle sizes. They were designed to classify particle diameter, d, into three different ranges: d < 2.28 μm, 2.28 μm ≤ d ≤ 3.20 μm, d > 3.20 μm. The QCM sensors were coated with a hydrogel, which was found to be a reliable adhesive for capturing aerosol particles. The QCM sensor coated with hydrogel was used to measure the mass loading of particles by utilizing its characteristic of resonant frequency shift. An integrated system has been demonstrated. PMID:22319317

  16. New Measurements of Aerosol Vertical Structure from Space using the NASA Geoscience Laser Altimeter System (GLAS): Applications for Aerosol Transport Models

    NASA Technical Reports Server (NTRS)

    Welton, E. J.; Spinhime, J.; Palm, S.; Hlavka, D.; Hart, W.; Ginoux, P.; Chin, M.; Colarco, P.

    2004-01-01

    In the past, satellite measurements of aerosols have only been possible using passive sensors. Analysis of passive satellite data has lead to an improved understanding of aerosol properties, spatial distribution, and their effect on the earth,s climate. However, direct measurement of aerosol vertical distribution has not been possible using only the passive data. Knowledge of aerosol vertical distribution is important to correctly assess the impact of aerosol absorption, for certain atmospheric correction procedures, and to help constrain height profiles in aerosol transport models. On January 12,2003 NASA launched the first satellite-based lidar, the Geoscience Laser Altimeter System (GLAS), onboard the ICESat spacecraft. GLAS is both an altimeter and an atmospheric lidar, and obtains direct measurements of aerosol and cloud heights. Here we show an overview of GLAS, provide an update of its current status, and discuss how GLAS data will be useful for modeling efforts. In particular, a strategy of using GLAS to characterize the height profile of dust plumes over source regions will be presented, along with initial results. Such information can be used to validate and improve output from aerosol transport models. Aerosol height profile comparisons between GLAS and transport models will be shown for regions downwind of aerosol sources. We will also discuss the feasibility of assimilating GLAS profiles into the models in order to improve their output.

  17. New Measurements of Aerosol Vertical Structure from Space Using the NASA Geoscience Laser Altimeter System (GLAS): Applications for Aerosol Transport Models

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Ginoux, Paul; Colarco, Peter; Chin, Mian; Spinhirne, James D.; Palm, Steven P.; Hlavka, Dennis; Hart, William

    2003-01-01

    In the past, satellite measurements of aerosols have only been possible using passive sensors. Analysis of passive satellite data has lead to an improved understanding of aerosol properties, spatial distribution, and their effect on the earth s climate. However, direct measurement of aerosol vertical distribution has not been possible using only the passive data. Knowledge of aerosol vertical distribution is important to correctly assess the impact of aerosol absorption, for certain atmospheric correction procedures, and to help constrain height profiles in aerosol transport models. On January 12,2003 NASA launched the first satellite-based lidar, the Geoscience Laser Altimeter System (GLAS), onboard the ICESat spacecraft. GLAS is both an altimeter and an atmospheric lidar, and obtains direct measurements of aerosol and cloud heights. Here we show an overview of GLAS, provide an update of its current status, and discuss how GUS data will be useful for modeling efforts. In particular, a strategy of using GLAS to characterize the height profile of dust plumes over source regions will be presented, along with initial results. Such information can be used to validate and improve output from aerosol transport models. Aerosol height profile comparisons between GLAS and transport models will be shown for regions downwind of aerosol sources. We will also discuss the feasibility of assimilating GLAS profiles into the models in order to improve their output,

  18. Multifunctional SMA-based smart inhaler system for improved aerosol drug delivery: design and fabrication

    NASA Astrophysics Data System (ADS)

    Pausley, Matthew E.; Seelecke, Stefan

    2008-03-01

    This paper documents the development of a prototype smart aerosol drug inhaler system using shape memory alloy (SMA) actuators. Unlike conventional dispersed-release inhalers, the smart inhaler system releases the aerosol drug in a very small area within the mouth inlet. Kleinstreuer and Zhang [1] have found that controlled release in the mouth inlet increases drug efficiency and allows targeting of specific sites within the lung. The methodology has been validated numerically and experimentally using fixed-exit position inhalers. The design presented in this work, however, allows for variation of nozzle exit position using SMA wire actuators in a combined actuator/sensor role. In contrast to other possible mechanisms, SMA wires are lightweight, require low power, and are the least obstructive to the flow of air through the inhaler. The dual actuator/sensor nature of the SMA wires (via resistance measurement) further simplifies the design. Solutions and insights into several SMA actuator design challenges are presented. SMA wire actuator characteristics such as achievable stroke and their effect on the design are highlighted. Consideration of actuator force requirements and the capabilities of SMA wires and studied. The problems posed by the thermal characteristics of SMA wires and innovative solutions are reported.

  19. A View of Earth's Aerosol System from Space to Your Office Chair

    NASA Technical Reports Server (NTRS)

    Colarco, Peter

    2008-01-01

    Aerosols are tiny particles and droplets suspended in the air. Each day you breathe in about 10 billion of them, about a half a million per breath. They are formed in nature by volcanoes, dust storms, sea spray, and emissions from vegetation. Humans create aerosols and alter their natural sources by burning fossil fuels and modifying land cover. Fires are another important source of aerosols; some are natural, such as wildfires started by lightning strikes, while others are from human-caused burning of vegetation for cooking, heating, and land clearing. Aerosols have complex effects on Earth's climate. In general, they cool the surface by reflecting (scattering) radiation from the sun back into space. Dust and smoke absorb solar radiation and heat the atmosphere where they are concentrated. Aerosols change the properties of clouds. Indeed, it would be very difficult to form clouds in the atmosphere without aerosols to act as 'seeds' for water to condense on. In aerosol polluted environments clouds tend to have smaller droplets than clouds formed in cleaner environments; these polluted clouds appear brighter from space because they reflect more sunlight, and they may persist longer and not rain as intensely. Aerosols also affect local air quality and visibility. Data collected by NASA satellites over the past decade have provided an unprecedented view of Earth's aerosol distribution and dramatically increased our understanding of where aerosols come from and just how far they travel in the atmosphere. In this talk I will discuss observations of aerosols from space and how they inform numerical transport models attempting to simulate the global aerosol system.

  20. Electrohydrodynamic Flows in Electrochemical Systems

    NASA Technical Reports Server (NTRS)

    Saville, D. A.

    2005-01-01

    Recent studies have established a new class of assembly processes with colloidal suspensions. Particles are driven together to form large crystalline structures in both dc and ac fields. The current work centers on this new class of flows in ac fields. In the research carried out under the current award, it was established that: (i) Small colloidal particles crystallize near an electrode due to electrohydrodynamic flows induced by an sinusoidally varying applied potential. (ii) These flows originate due to disturbances in the electrode polarization layer arising from the presence of the particles. Inasmuch as the charge and the field strength both scale on the applied field, the flows are proportional to the square of the applied voltage. (iii) Suspensions of two different sorts of particles can be crystallized and will form well-ordered binary crystals. (iv) At high frequencies the EHD flows die out. Thus, with a homogeneous system the particles become widely spaced due to dipolar repulsion. With a binary suspension, however, the particles may become attractive due to dipolar attraction arising from differences in electrokinetic dipoles. Consequently binary crystals form at both high and low frequencies.

  1. Distinct Impacts of Aerosols on an Evolving Continental Cloud System during the RACORO Field Campaign

    NASA Astrophysics Data System (ADS)

    Lin, Y.; Wang, Y.; Zhang, R.; Liu, Y.

    2015-12-01

    Aerosol-cloud interactions have been investigated extensively but still remain high uncertainty due to the complexity of cloud microphysical processes under various dynamic and thermodynamic environments. Cloud-resolving Weather Research and Forecast (CR-WRF) model implemented with a two-moment bulk microphysics and a modified Goddard radiation scheme is employed to investigate aerosol effects on different cloud regimes and their transitions associated with a continental cloud system occurring from 25 May to 27 May, 2009 during the Department of Energy Atmospheric Radiation Measurement Routine AAF Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. The simulated cloud properties and precipitation for the three different cloud regimes, including shallow cumuli, a deep convective cloud (DCC), and a stratus exhibit overall agreements with airborne and ground-based observations. Sensitivity studies with different aerosol scenarios reveal that the responses of cloud micro- and macrophysics to aerosol loading depend on the cloud regimes with monotonic or non-monotonic trend. Aerosol radiative effects modify the atmospheric thermodynamic condition and change the atmospheric stability, which induce different response from aerosol indirect effects. Our results also indicate that the overall aerosol effects on a cloud complex are distinct from those of the individual cloud types. The aerosol-cloud interaction for the different cloud regimes should be evaluated to assess the aerosol direct and indirect radiative forcings on regional and global climate.

  2. Analysis of DIAL/HSRL aerosol backscatter and extinction profiles during the SEAC4RS campaign with an aerosol assimilation system

    NASA Astrophysics Data System (ADS)

    Weaver, C. J.; da Silva, A. M., Jr.; Colarco, P. R.; Randles, C. A.

    2015-12-01

    We retrieve aerosol concentrations and optical information from vertical profiles of airborne 532 nm extinction and 532 and 1064 nm backscatter measurements made during the SEAC4RS summer 2013 campaign. The observations are from the High Spectral Resolution Lidar (HSRL) Airborne Differential Absorption Lidar (DIAL) on board the NASA DC-8. Instead of retrieving information about aerosol microphysical properties such as indexes of refraction, we seek information more directly applicable to an aerosol transport model - in our case the Goddard Chemistry Aerosol Radiation and Transport (GOCART) module used in the GEOS-5 Earth modeling system. A joint atmosphere/aerosol mini-reanalysis was performed for the SEAC4RS period using GEOS-5. The meteorological reanalysis followed the MERRA-2 atmospheric reanalysis protocol, and aerosol information from MODIS, MISR, and AERONET provided a constraint on the simulated aerosol optical depth (i.e., total column loading of aerosols). We focus on the simulated concentrations of 10 relevant aerosol species simulated by the GOCART module: dust, sulfate, and organic and black carbon. Our first retrieval algorithm starts with the SEAC4RS mini-reanalysis and adjusts the concentration of each GOCART aerosol species so that differences between the observed and simulated backscatter and extinction measurements are minimized. In this case, too often we are unable to simulate the observations by simple adjustment of the aerosol concentrations. A second retrieval approach adjusts both the aerosol concentrations and the optical parameters (i.e., assigned mass extinction efficiency) associated with each GOCART species. We present results from DC-8 flights over smoke from forest fires over the western US using both retrieval approaches. Finally, we compare our retrieved quantities with in-situ observations of aerosol absorption, scattering, and mass concentrations at flight altitude.

  3. Towards depth profiling of organic aerosols in real time using aerosol flowing atmospheric-pressure afterglow mass spectrometry (AeroFAPA-MS)

    NASA Astrophysics Data System (ADS)

    Brüggemann, Martin; Hoffmann, Thorsten

    2014-05-01

    Organic aerosol accounts for a substantial fraction of tropospheric aerosol and has implications on the earth's climate and human health. However, the characterization of its chemical composition and transformations remain a major challenge and is still connected to large uncertainties (IPCC, 2013). Recent measurements revealed that organic aerosol particles may reside in an amorphous or semi-solid phase state which impedes the diffusion within the particles (Virtanen et al., 2010; Shiraiwa et al., 2011). This means that reaction products which are formed on the surface of a particle, e.g. by OH, NO3 or ozone chemistry, cannot diffuse into the particle's core and remain at the surface. Eventually, this leads to particles with a core/shell structure. In the particles' cores the initial compounds are preserved whereas the shells contain mainly the oxidation products. By analyzing the particles' cores and shells separately, thus, it is possible to obtain valuable information on the formation and evolution of the aerosols' particle and gas phase. Here we present the development of the aerosol flowing atmospheric-pressure afterglow (AeroFAPA) technique which allows the mass spectrometric analysis of organic aerosols in real time. The AeroFAPA is an ion source based on a helium glow discharge at atmospheric pressure. The plasma produces excited helium species and primary reagent ions which are transferred into the afterglow region where the ionization of the analytes takes place. Due to temperatures of only 80 ° C to 150 ° C and ambient pressure in the afterglow region, the ionization is very soft and almost no fragmentation of organic molecules is observed. Thus, the obtained mass spectra are easy to interpret and no extensive data analysis procedure is necessary. Additionally, first results of a combination of the AeroFAPA-MS with a scanning mobility particle sizer (SMPS) suggest that it is not only possible to analyze the entire particle phase but rather that a

  4. In situ infrared aerosol spectroscopy for a variety of nerve agent simulants using flow-through photoacoustics.

    PubMed

    Gurton, Kristan P; Felton, Melvin; Dahmani, Rachid; Ligon, David

    2007-09-01

    We present newly measured results of an ongoing experimental program established to measure optical cross sections in the mid- and long-wave infrared for a variety of chemically and biologically based aerosols. For this study we consider only chemically derived aerosols, and in particular, a group of chemical compounds often used as simulants for the detection of extremely toxic organophosphorus nerve agents. These materials include: diethyl methylphosphonate (DEMP), dimethyl methylphosphonate (DMMP), diisopropyl methylphosphonate (DIMP), and diethyl phthalate (DEP). As reported in a prior study [Appl. Opt. 44, 4001 (2005)], we combine two optical techniques well suited for aerosol spectroscopy [i.e., flow-through photoacoustics and Fourier transform infrared (FTIR) emission spectroscopy], to measure in situ the absolute extinction and absorption cross sections over a variety of wavelengths spanning the IR spectral region from 3 to 13 mum. Aerosol size distribution(s), particle number density, and dosimetric measurements are recorded simultaneously in order to present optical cross sections that are aerosol mass normalized, i.e., m(2)/gram. Photoacoustic results, conducted at a series of CO(2) laser lines, compare well with measured broadband FTIR spectral extinction. Both FTIR and photoacoustic data also compare well with Mie theory calculations based on measured size distributions and previously published complex indices of refraction. PMID:17805369

  5. In situ infrared aerosol spectroscopy for a variety of nerve agent simulants using flow-through photoacoustics

    NASA Astrophysics Data System (ADS)

    Gurton, Kristan P.; Felton, Melvin; Dahmani, Rachid; Ligon, David

    2007-09-01

    We present newly measured results of an ongoing experimental program established to measure optical cross sections in the mid- and long-wave infrared for a variety of chemically and biologically based aerosols. For this study we consider only chemically derived aerosols, and in particular, a group of chemical compounds often used as simulants for the detection of extremely toxic organophosphorus nerve agents. These materials include: diethyl methylphosphonate (DEMP), dimethyl methylphosphonate (DMMP), diisopropyl methylphosphonate (DIMP), and diethyl phthalate (DEP). As reported in a prior study [Appl. Opt. 44, 4001 (2005)], we combine two optical techniques well suited for aerosol spectroscopy [i.e., flow-through photoacoustics and Fourier transform infrared (FTIR) emission spectroscopy], to measure in situ the absolute extinction and absorption cross sections over a variety of wavelengths spanning the IR spectral region from 3 to 13 μm. Aerosol size distribution(s), particle number density, and dosimetric measurements are recorded simultaneously in order to present optical cross sections that are aerosol mass normalized, i.e., m2/gram. Photoacoustic results, conducted at a series of CO2 laser lines, compare well with measured broadband FTIR spectral extinction. Both FTIR and photoacoustic data also compare well with Mie theory calculations based on measured size distributions and previously published complex indices of refraction.

  6. The Cloud-Aerosol Transport System (CATS): a New Lidar for Aerosol and Cloud Profiling from the International Space Station

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; McGill, Matthew J.; Yorks, John E.; Hlavka, Dennis L.; Hart, William D.; Palm, Stephen P.; Colarco, Peter R.

    2011-01-01

    Spaceborne lidar profiling of aerosol and cloud layers has been successfully implemented during a number of prior missions, including LITE, ICESat, and CALIPSO. Each successive mission has added increased capability and further expanded the role of these unique measurements in wide variety of applications ranging from climate, to air quality, to special event monitoring (ie, volcanic plumes). Many researchers have come to rely on the availability of profile data from CALIPSO, especially data coincident with measurements from other A-Train sensors. The CALIOP lidar on CALIPSO continues to operate well as it enters its fifth year of operations. However, active instruments have more limited lifetimes than their passive counterparts, and we are faced with a potential gap in lidar profiling from space if the CALIOP lidar fails before a new mission is operational. The ATLID lidar on EarthCARE is not expected to launch until 2015 or later, and the lidar component of NASA's proposed Aerosols, Clouds, and Ecosystems (ACE) mission would not be until after 2020. Here we present a new aerosol and cloud lidar that was recently selected to provide profiling data from the International Space Station (ISS) starting in 2013. The Cloud-Aerosol Transport System (CATS) is a three wavelength (1064, 532, 355 nm) elastic backscatter lidar with HSRL capability at 532 nm. Depolarization measurements will be made at all wavelengths. The primary objective of CATS is to continue the CALIPSO aerosol and cloud profile data record, ideally with overlap between both missions and EarthCARE. In addition, the near real time data capability of the ISS will enable CATS to support operational applications such as air quality and special event monitoring. The HSRL channel will provide a demonstration of technology and a data testbed for direct extinction retrievals in support of ACE mission development. An overview of the instrument and mission will be provided, along with a summary of the science

  7. Cascade redox flow battery systems

    DOEpatents

    Horne, Craig R.; Kinoshita, Kim; Hickey, Darren B.; Sha, Jay E.; Bose, Deepak

    2014-07-22

    A reduction/oxidation ("redox") flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

  8. Determination of organic compounds from wood combustion aerosol nanoparticles by different gas chromatographic systems and by aerosol mass spectrometry.

    PubMed

    Laitinen, Totti; Martín, Sara Herrero; Parshintsev, Jevgeni; Hyötyläinen, Tuulia; Hartonen, Kari; Riekkola, Marja-Liisa; Kulmala, Markku; Pavón, José Luis Pérez

    2010-01-01

    Organic compounds in atmospheric nanoparticles have an effect on human health and the climate. The determination of these particles is challenged by the difficulty of sampling, the complexity of sample composition, and the trace-level concentrations of the compounds. Meeting the challenge requires the development of sophisticated sampling systems for size-resolved particles and the optimization of sensitive, accurate and simple analytical techniques and methods. A new sampling system is proposed where particles are charged with a bipolar charger and size-segregated with a differential mobility analyzer. This system was successfully used to sample particles from wood pyrolysis with particle sizes 30-100nm. Particles were analyzed by four techniques: comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry, gas chromatography-time-of-flight mass spectrometry, gas chromatography-quadrupole mass spectrometry, and aerosol mass spectrometry (aerosol MS). In the chromatographic techniques, particles were collected on a filter and analyzed off-line after sample preparation, whereas in the aerosol MS, particle analysis was performed directly from the particle source. Target compounds of the samples were polyaromatic hydrocarbons and n-alkanes. The analytical techniques were compared and their advantages and disadvantages were evaluated. The sampling system operated well and target compounds were identified in low concentrations. PMID:19945113

  9. Information-Systems Data-Flow Diagram

    NASA Technical Reports Server (NTRS)

    Blosiu, J. O.

    1983-01-01

    Single form presents clear picture of entire system. Form giving relational review of data flow well suited to information system planning, analysis, engineering, and management. Used to review data flow for developing system or one already in use.

  10. A Marine Aerosol Reference Tank system as a breaking wave analogue for the production of foam and sea-spray aerosols

    NASA Astrophysics Data System (ADS)

    Stokes, M. D.; Deane, G. B.; Prather, K.; Bertram, T. H.; Ruppel, M. J.; Ryder, O. S.; Brady, J. M.; Zhao, D.

    2013-04-01

    In order to better understand the processes governing the production of marine aerosols a repeatable, controlled method for their generation is required. The Marine Aerosol Reference Tank (MART) has been designed to closely approximate oceanic conditions by producing an evolving bubble plume and surface foam patch. The tank utilizes an intermittently plunging sheet of water and large volume tank reservoir to simulate turbulence, plume and foam formation, and the water flow is monitored volumetrically and acoustically to ensure the repeatability of conditions.

  11. Direct and indirect radiative effects of aerosols using the coupled system of aerosol HAM module and the Weather Research and Forecasting (WRF) model

    NASA Astrophysics Data System (ADS)

    Mashayekhi, Rabab; Irannejad, Parviz; Feichter, Johann; Akbari Bidokhti, Abbas Ali Ali

    2010-05-01

    The fully coupled aerosol-cloud and radiation WRF-HAM modeling system is presented. The aerosol HAM model is implemented within the chemistry version of WRF modeling system. HAM is based on a "pseudo-modal" approach for representation of the particle size distribution. Aerosols are grouped into four geometrical size classes and two types of mixed and insoluble particles. The aerosol components considered are sulfate, black carbon, particulate organic matter, sea salt and mineral dust. Microphysical processes including nucleation, condensation and coagulation of aerosol particles are considered using the microphysics M7 scheme. Horizontal transport of the aerosol particles is simulated using the advection scheme in WRF. Convective transport and vertical mixing of aerosol particles are also considered in the coupled system. A flux-resistance method is used for dry deposition of aerosol particles. Aerosol sizes and chemical compositions are used to determine the aerosol optical properties. Direct effects of aerosols on incoming shortwave radiation flux are simulated by transferring the aerosol optical parameters to the Goddard shortwave radiation scheme. Indirect effects of aerosols are simulated by using a prognostic treatment of cloud droplet number and adding modules that activate aerosol particles to form cloud droplets. The first and second indirect effects, i.e. the interactions of clouds and incoming solar radiation are implemented in WRF-Chem by linking the simulated cloud droplet number with the Goddard shortwave radiation scheme and the Lin et al. microphysics scheme. The simulations are carried out for a 6-day period from 22 to 28 February 2006 in a domain with 30-km grid spacing, encompassing the south-western Asia, North Africa and some parts of Europe. The results show a negative radiative forcing over most parts of the domain, mainly due to the presence of mineral dust aerosols. The simulations are evaluated using the measured downward radiation in

  12. Effect of small flow reversals on aerosol mixing in the alveolar region of the human lung.

    PubMed

    Darquenne, Chantal; Prisk, G Kim

    2004-12-01

    It has been suggested that irreversibility of alveolar flow combined with a stretched and folded pattern of streamlines can lead to a sudden increase in mixing in the lung. To determine whether this phenomenon is operative in the human lung in vivo, we performed a series of bolus studies with a protocol designed to induce complex folding patterns. Boli of 0.5- and 1-microm-diameter particles were inhaled at penetration volumes (V(p)) of 300 and 1,200 ml in eight subjects during short periods of microgravity aboard the National Aeronautics and Space Administration Microgravity Research Aircraft. Inspiration was from residual volume to 1 liter above 1 G functional residual capacity. This was followed by a 10-s breathhold, during which up to seven 100-ml flow reversals (FR) were imposed at V(p) = 300 ml and up to four 500-ml FR at V(p) = 1,200 ml, and by an expiration to residual volume. Bolus dispersion and deposition were calculated from aerosol concentration and flow rate continuously monitored at the mouth. There was no significant increase in dispersion and deposition with increasing FR except for dispersion between 0 and 7 FR at V(p) = 300 ml with 0.5-microm-diameter particles, and this increase was small. This suggested that either the phenomenon of stretch and fold did not occur within the number of FR we performed or that it had already occurred during the one breathing cycle included in the basic maneuver. We speculate that the phenomenon occurred during the basic maneuver, which is consistent with the high degree of dispersion and deposition observed previously in microgravity. PMID:15298988

  13. Aerosol-Cloud-Precipitation Interactions in the Climate System

    NASA Astrophysics Data System (ADS)

    Andreae, M. O.

    2015-12-01

    Aerosols serve as cloud condensation nuclei (CCN) and thus have a powerful effect on cloud properties. Increased aerosol concentrations resulting from pollution lead to higher cloud droplet concentrations, but smaller droplet sizes. This in turn affects the physical processes inside clouds that lead to the initiation of precipitation. Depending on a number of factors, including aerosol composition, atmospheric stability, and cloud water content, increasing CCN concentrations may either decrease or increase rainfall. In convective clouds, early rain formation is suppressed, which makes more water and energy available to rise higher in the atmosphere and form ice particles. This may invigorate the dynamics of convection, encourage the formation of hail and lightning, and enhance the transport of materials to the upper troposphere. In turn, cloud processing also affects the concentrations, composition, and distribution of atmospheric aerosols. In order to understand and quantify the effects of air pollution on climate, and precipitation in particular, knowledge of natural abundance and characteristics of aerosols is as essential as the observation of perturbed conditions. I will present recent advances in the conceptual understanding of aerosol-precipitation interactions, as well as results of measurements on aerosol and cloud characteristics in pristine and polluted conditions.

  14. Vertical profiles of atmospheric fluorescent aerosols observed by a mutil-channel lidar spectrometer system

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Huang, J.; Zhou, T.; Sugimoto, N.; Bi, J.

    2015-12-01

    Zhongwei Huang1*, Jianping Huang1, Tian Zhou1, Nobuo Sugimoto2, Jianrong Bi1 and Jinsen Shi11Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, China. 2Atmospheric Environment Division, National Institutes for Environmental Studies, Tsukuba, Japan Email: huangzhongwei@lzu.edu.cn Abstract Atmospheric aerosols have a significant impact on regional and globe climate. The challenge in quantifying aerosol direct radiative forcing and aerosol-cloud interactions arises from large spatial and temporal heterogeneity of aerosol concentrations, compositions, sizes, shape and optical properties (IPCC, 2007). Lidar offers some remarkable advantages for determining the vertical structure of atmospheric aerosols and their related optical properties. To investigate the characterization of atmospheric aerosols (especially bioaerosols) with high spatial and temporal resolution, we developed a Raman/fluorescence/polarization lidar system employed a multi-channel spectrometer, with capabilities of providing measurements of Raman scattering and laser-induced fluorescence excitation at 355 nm from atmospheric aerosols. Meanwhile, the lidar system operated polarization measurements both at 355nm and 532nm wavelengths, aiming to obtain more information of aerosols. It employs a high power pulsed laser and a received telescope with 350mm diameter. The receiver could simultaneously detect a wide fluorescent spectrum about 178 nm with spectral resolution 5.7 nm, mainly including an F/3.7 Crossed Czerny-Turner spectrograph, a grating (1200 gr/mm) and a PMT array with 32 photocathode elements. Vertical structure of fluorescent aerosols in the atmosphere was observed by the developed lidar system at four sites across northwest China, during 2014 spring field observation that conducted by Lanzhou University. It has been proved that the developed lidar could detect the fluorescent aerosols with high temporal and

  15. EFFECTS OF SULFURIC ACID AEROSOLS ON VEGETATION

    EPA Science Inventory

    A continuous flow system for exposing plants to submicron aerosols of sulfuric acid has been developed and an operational model has been constructed. Exposure chambers have been designed to allow simultaneous exposures of the same plant to aerosol and control environments. All su...

  16. Development of the Ensemble Navy Aerosol Analysis Prediction System (ENAAPS) and its application of the Data Assimilation Research Testbed (DART) in support of aerosol forecasting

    NASA Astrophysics Data System (ADS)

    Rubin, Juli I.; Reid, Jeffrey S.; Hansen, James A.; Anderson, Jeffrey L.; Collins, Nancy; Hoar, Timothy J.; Hogan, Timothy; Lynch, Peng; McLay, Justin; Reynolds, Carolyn A.; Sessions, Walter R.; Westphal, Douglas L.; Zhang, Jianglong

    2016-03-01

    An ensemble-based forecast and data assimilation system has been developed for use in Navy aerosol forecasting. The system makes use of an ensemble of the Navy Aerosol Analysis Prediction System (ENAAPS) at 1 × 1°, combined with an ensemble adjustment Kalman filter from NCAR's Data Assimilation Research Testbed (DART). The base ENAAPS-DART system discussed in this work utilizes the Navy Operational Global Analysis Prediction System (NOGAPS) meteorological ensemble to drive offline NAAPS simulations coupled with the DART ensemble Kalman filter architecture to assimilate bias-corrected MODIS aerosol optical thickness (AOT) retrievals. This work outlines the optimization of the 20-member ensemble system, including consideration of meteorology and source-perturbed ensemble members as well as covariance inflation. Additional tests with 80 meteorological and source members were also performed. An important finding of this work is that an adaptive covariance inflation method, which has not been previously tested for aerosol applications, was found to perform better than a temporally and spatially constant covariance inflation. Problems were identified with the constant inflation in regions with limited observational coverage. The second major finding of this work is that combined meteorology and aerosol source ensembles are superior to either in isolation and that both are necessary to produce a robust system with sufficient spread in the ensemble members as well as realistic correlation fields for spreading observational information. The inclusion of aerosol source ensembles improves correlation fields for large aerosol source regions, such as smoke and dust in Africa, by statistically separating freshly emitted from transported aerosol species. However, the source ensembles have limited efficacy during long-range transport. Conversely, the meteorological ensemble generates sufficient spread at the synoptic scale to enable observational impact through the ensemble data

  17. Development of the Ensemble Navy Aerosol Analysis Prediction System (ENAAPS) and its application of the Data Assimilation Research Testbed (DART) in support of aerosol forecasting

    NASA Astrophysics Data System (ADS)

    Rubin, J. I.; Reid, J. S.; Hansen, J. A.; Anderson, J. L.; Collins, N.; Hoar, T. J.; Hogan, T.; Lynch, P.; McLay, J.; Reynolds, C. A.; Sessions, W. R.; Westphal, D. L.; Zhang, J.

    2015-10-01

    An ensemble-based forecast and data assimilation system has been developed for use in Navy aerosol forecasting. The system makes use of an ensemble of the Navy Aerosol Analysis Prediction System (ENAAPS) at 1° × 1°, combined with an Ensemble Adjustment Kalman Filter from NCAR's Data Assimilation Research Testbed (DART). The base ENAAPS-DART system discussed in this work utilizes the Navy Operational Global Analysis Prediction System (NOGAPS) meteorological ensemble to drive offline NAAPS simulations coupled with the DART Ensemble Kalman Filter architecture to assimilate bias-corrected MODIS Aerosol Optical Thickness (AOT) retrievals. This work outlines the optimization of the 20-member ensemble system, including consideration of meteorology and source-perturbed ensemble members as well as covariance inflation. Additional tests with 80 meteorological and source members were also performed. An important finding of this work is that an adaptive covariance inflation method, which has not been previously tested for aerosol applications, was found to perform better than a temporally and spatially constant covariance inflation. Problems were identified with the constant inflation in regions with limited observational coverage. The second major finding of this work is that combined meteorology and aerosol source ensembles are superior to either in isolation and that both are necessary to produce a robust system with sufficient spread in the ensemble members as well as realistic correlation fields for spreading observational information. The inclusion of aerosol source ensembles improves correlation fields for large aerosol source regions such as smoke and dust in Africa, by statistically separating freshly emitted from transported aerosol species. However, the source ensembles have limited efficacy during long range transport. Conversely, the meteorological ensemble produces sufficient spread at the synoptic scale to enable observational impact through the ensemble data

  18. Feasibility Study For A Spaceborne Ozone/Aerosol Lidar System

    NASA Technical Reports Server (NTRS)

    Campbell, Richard E.; Browell, Edward V.; Ismail, Syed; Dudelzak, Alexander E.; Carswell, Allan I.; Ulitsky, Arkady

    1997-01-01

    Because ozone provides a shield against harmful ultraviolet radiation, determines the temperature profile in the stratosphere, plays important roles in tropospheric chemistry and climate, and is a health risk near the surface, changes in natural ozone layers at different altitudes and their global impact are being intensively researched. Global ozone coverage is currently provided by passive optical and microwave satellite sensors that cannot deliver high spatial resolution measurements and have particular limitations in the troposphere. Vertical profiling DIfferential Absorption Lidars (DIAL) have shown excellent range-resolved capabilities, but these systems have been large, inefficient, and have required continuous technical attention for long term operations. Recently, successful, autonomous DIAL measurements have been performed from a high-altitude aircraft (LASE - Lidar Atmospheric Sensing Experiment), and a space-qualified aerosol lidar system (LITE - Laser In-space Technology Experiment) has performed well on Shuttle. Based on the above successes, NASA and the Canadian Space Agency are jointly studying the feasibility of developing ORACLE (Ozone Research with Advanced Cooperative Lidar Experiments), an autonomously operated, compact DIAL instrument to be placed in orbit using a Pegasus class launch vehicle.

  19. Development and characterization of a resistance spot welding aerosol generator and inhalation exposure system.

    PubMed

    Afshari, Aliakbar; Zeidler-Erdely, Patti C; McKinney, Walter; Chen, Bean T; Jackson, Mark; Schwegler-Berry, Diane; Friend, Sherri; Cumpston, Amy; Cumpston, Jared L; Leonard, H Donny; Meighan, Terence G; Frazer, David G; Antonini, James M

    2014-10-01

    Limited information exists regarding the health risks associated with inhaling aerosols that are generated during resistance spot welding of metals treated with adhesives. Toxicology studies evaluating spot welding aerosols are non-existent. A resistance spot welding aerosol generator and inhalation exposure system was developed. The system was designed by directing strips of sheet metal that were treated with an adhesive to two electrodes of a spot welder. Spot welds were made at a specified distance from each other by a computer-controlled welding gun in a fume collection chamber. Different target aerosol concentrations were maintained within the exposure chamber during a 4-h exposure period. In addition, the exposure system was run in two modes, spark and no spark, which resulted in different chemical profiles and particle size distributions. Complex aerosols were produced that contained both metal particulates and volatile organic compounds (VOCs). Size distribution of the particles was multi-modal. The majority of particles were chain-like agglomerates of ultrafine primary particles. The submicron mode of agglomerated particles accounted for the largest portion of particles in terms of particle number. Metal expulsion during spot welding caused the formation of larger, more spherical particles (spatter). These spatter particles appeared in the micron size mode and accounted for the greatest amount of particles in terms of mass. With this system, it is possible to examine potential mechanisms by which spot welding aerosols can affect health, as well as assess which component of the aerosol may be responsible for adverse health outcomes. PMID:25140455

  20. Aerosols in the Convective Boundary Layer: Radiation Effects on the Coupled Land-Atmosphere System

    NASA Astrophysics Data System (ADS)

    Barbaro, E.; Vila-Guerau Arellano, J.; Ouwersloot, H. G.; Schroter, J.; Donovan, D. P.; Krol, M. C.

    2013-12-01

    We investigate the responses of the surface energy budget and the convective boundary-layer (CBL) dynamics to the presence of aerosols using a combination of observations and numerical simulations. A detailed observational dataset containing (thermo)dynamic variables observed at CESAR (Cabauw Experimental Site for Atmospheric Research) and aerosol information from the European Integrated Project on Aerosol, Cloud, Climate, and Air Quality Interactions (IMPACT/EUCAARI) campaign is employed to design numerical experiments reproducing two prototype clear-sky days characterized by: (i) a well-mixed residual layer above a ground inversion and (ii) a continuously growing CBL. A large-eddy simulation (LES) model and a mixed-layer (MXL) model, both coupled to a broadband radiative transfer code and a land-surface model, are used to study the impacts of aerosol scattering and absorption of shortwave radiation on the land-atmosphere system. We successfully validate our model results using the measurements of (thermo)dynamic variables and aerosol properties for the two different CBL prototypes studied here. Our findings indicate that in order to reproduce the observed surface energy budget and CBL dynamics, information of the vertical structure and temporal evolution of the aerosols is necessary. Given the good agreement between the LES and the MXL model results, we use the MXL model to explore the aerosol effect on the land-atmosphere system for a wide range of optical depths and single scattering albedos. Our results show that higher loads of aerosols decrease irradiance, imposing an energy restriction at the surface. Over the studied well-watered grassland, aerosols reduce the sensible heat flux more than the latent heat flux. As a result, aerosols increase the evaporative fraction. Moreover, aerosols also delay the CBL morning onset and anticipate its afternoon collapse. If also present above the CBL during the morning transition, aerosols maintain a persistent near

  1. The expanding role of aerosols in systemic drug delivery, gene therapy, and vaccination.

    PubMed

    Laube, Beth L

    2005-09-01

    Aerosolized medications have been used for centuries to treat respiratory diseases. Until recently, inhalation therapy focused primarily on the treatment of asthma and chronic obstructive pulmonary disease, and the pressurized metered-dose inhaler was the delivery device of choice. However, the role of aerosol therapy is clearly expanding beyond that initial focus. This expansion has been driven by the Montreal protocol and the need to eliminate chlorofluorocarbons (CFCs) from traditional metered-dose inhalers, by the need for delivery devices and formulations that can efficiently and reproducibly target the systemic circulation for the delivery of proteins and peptides, and by developments in medicine that have made it possible to consider curing lung diseases with aerosolized gene therapy and preventing epidemics of influenza and measles with aerosolized vaccines. Each of these drivers has contributed to a decade or more of unprecedented research and innovation that has altered how we think about aerosol delivery and has expanded the role of aerosol therapy into the fields of systemic drug delivery, gene therapy, and vaccination. During this decade of innovation, we have witnessed the coming of age of dry powder inhalers, the development of new soft mist inhalers, and improved pressurized metered-dose inhaler delivery as a result of the replacement of CFC propellants with hydrofluoroalkane. The continued expansion of the role of aerosol therapy will probably depend on demonstration of the safety of this route of administration for drugs that have their targets outside the lung and are administered long term (eg, insulin aerosol), on the development of new drugs and drug carriers that can efficiently target hard-to-reach cell populations within the lungs of patients with disease (eg, patients with cystic fibrosis or lung cancer), and on the development of devices that improve aerosol delivery to infants, so that early intervention in disease processes with aerosol

  2. Comparison of an Aerosol Assimilation System of MODIS Radiances with AERONET retrievals.

    NASA Astrophysics Data System (ADS)

    Weaver, C.; Chin, M.; da Silva, A.; Ginoux, P.

    2004-12-01

    We present results from a simple off-line assimilation system of the radiances from the 7 MODIS channels that sense atmospheric aerosols. We describe the assimilation cycle. The Goddard Chemistry and Aerosol Radiation Transport Model (GOCART), which is driven by assimilated meteorology, simulates five aerosol types: dust, seasalt, black carbon, organic carbon and sulfate. The forward model takes the aerosol information from the GOCART model and calculates radiances based on optical parameters of the aerosol type, satellite viewing angle and the particle growth from relative humidity. Because the GOCART model is driven by previously assimilated meteorology, these forward model radiances can be directly compared with the observed MODIS level2 radiances. The off-line assimilation system simply adjusts the aerosol loading in the GOCART model so that the observed minus forward model (O-F) radiances agree. Minimal change is made to the GOCART aerosol vertical distribution, size distribution and the ratio of the five different aerosol types. The loading in the GOCART model is updated with new MODIS observations every 6 hours. Since the previously assimilated meteorology provides surface wind speed, we account for radiance sensitivity to wind speed over rough ocean. Over land we use surface albedoes from the MODIS land team kindly provided by Eric Moody. Over ocean the assimilation aerosol optical depths (AOD) compare well with AERONET, over land less so. We compare our results with AERONET retrieved single scattering albedo and effective radius. We also investigate data retention issues in the assimilation. This research is part of an ongoing effort at NASA Goddard to integrate aerosols into the Goddard Modeling and Assimilation Office (GMAO) products.

  3. The Cloud-Aerosol Transport System (CATS): A New Lidar for Aerosol and Cloud Profiling from the International Space Station

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; McGill, Mathew J.; Yorks. John E.; Hlavka, Dennis L.; Hart, William D.; Palm, Stephen P.; Colarco, Peter R.

    2012-01-01

    Spaceborne lidar profiling of aerosol and cloud layers has been successfully implemented during a number of prior missions, including LITE, ICESat, and CALIPSO. Each successive mission has added increased capability and further expanded the role of these unique measurements in wide variety of applications ranging from climate, to air quality, to special event monitoring (ie, volcanic plumes). Many researchers have come to rely on the availability of profile data from CALIPSO, especially data coincident with measurements from other A-Train sensors. The CALIOP lidar on CALIPSO continues to operate well as it enters its fifth year of operations. However, active instruments have more limited lifetimes than their passive counterparts, and we are faced with a potential gap in lidar profiling from space if the CALIOP lidar fails before a new mission is operational. The ATLID lidar on EarthCARE is not expected to launch until 2015 or later, and the lidar component of NASA's proposed Aerosols, Clouds, and Ecosystems (ACE) mission would not be until after 2020. Here we present a new aerosol and cloud lidar that was recently selected to provide profiling data from the International Space Station (ISS) starting in 2013. The Cloud-Aerosol Transport System (CATS) is a three wavelength (1064,532,355 nm) elastic backscatter lidar with HSRL capability at 532 nm. Depolarization measurements will be made at all wavelengths. The primary objective of CATS is to continue the CALIPSO aerosol and cloud profile data record, ideally with overlap between both missions and EarthCARE. In addition, the near real time (NRT) data capability ofthe ISS will enable CATS to support operational applications such as aerosol and air quality forecasting and special event monitoring. The HSRL channel will provide a demonstration of technology and a data testbed for direct extinction retrievals in support of ACE mission development. An overview of the instrument and mission will be provided, along with a

  4. Mode shift of an inhaled aerosol bolus is correlated with flow sequencing in the human lung

    NASA Technical Reports Server (NTRS)

    Mills, Christopher N.; Darquenne, Chantal; Prisk, G. Kim; West, J. B. (Principal Investigator)

    2002-01-01

    We studied the effects on aerosol bolus inhalations of small changes in convective inhomogeneity induced by posture change from upright to supine in nine normal subjects. Vital capacity single-breath nitrogen washout tests were used to determine ventilatory inhomogeneity change between postures. Relative to upright, supine phase III slope was increased 33 +/- 11% (mean +/- SE, P < 0.05) and phase IV height increased 25 +/- 11% (P < 0.05), consistent with an increase in convective inhomogeneity likely due to increases in flow sequencing. Subjects also performed 0.5-microm-particle bolus inhalations to penetration volumes (V(p)) between 150 and 1,200 ml during a standardized inhalation from residual volume to 1 liter above upright functional residual capacity. Mode shift (MS) in supine posture was more mouthward than upright at all V(p), changing by 11.6 ml at V(p) = 150 ml (P < 0.05) and 38.4 ml at V(p) = 1,200 ml (P < 0.05). MS and phase III slope changes correlated positively at deeper V(p). Deposition did not change at any V(p), suggesting that deposition did not cause the MS change. We propose that the MS change results from increased sequencing in supine vs. upright posture.

  5. Aerosol mobility size spectrometer

    DOEpatents

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  6. Amphiphilic Systems under shear flow

    NASA Astrophysics Data System (ADS)

    Guo, Hongxia

    2008-03-01

    Phase behavior and the related physical and rheological properties of the amphiphilic systems including liquid crystals, diblock copolymers and surfactants are of wide-spread interest, e.g. in industrial processing of layered materials or biological applications of lipid membranes. For example, submitted to an applied shear flow, these lamellae show an interesting coupling of the layer orientation and the flow field. Despite an extensive literature dealing with the shear-induced transition, the underlying causes and mechanisms of the transition remain largely speculative. The experimental similarities between systems of different molecular constituents indicate, that the theoretical description of these reorientations can be constructed, from a common generic basis. Hence one can develop an efficient computer model which is able to reproduce the properties pertinent to real amphiphilic systems, and allows for a large-scale simulation. Here, I employed a simplified continuum amphiphilic computer model to investigate the shear--induced disorder-order, order-order and alignment flipping by large-scale parallelized (none) equilibrium molecular dynamics simulation

  7. Characterization of the Aerosol Instrument Package for the In-service Aircraft Global Observing System IAGOS

    NASA Astrophysics Data System (ADS)

    Bundke, Ulrich; Berg, Marcel; Tettig, Frank; Franke, Harald; Petzold, Andreas

    2015-04-01

    The atmospheric aerosol influences the climate twofold via the direct interaction with solar radiation and indirectly effecting microphysical properties of clouds. The latter has the largest uncertainty according to the last IPPC Report. A measured in situ climatology of the aerosol microphysical properties is needed to reduce the reported uncertainty of the aerosol climate impact. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System; www.iagos.org) responds to the increasing requests for long-term, routine in situ observational data by using commercial passenger aircraft as measurement platform. However, scientific instrumentation for the measurement of atmospheric constituents requires major modifications before being deployable aboard in-service passenger aircraft. The IAGOS Aerosol Package (IAGOS-P2C) consists of two modified Butanol based CPCs (Model Grimm 5.410) and one optical particle counter (Model Grimm Sky OPC 1.129). A thermodenuder at 250°C is placed upstream the second CPC, thus the number concentrations of the total aerosol and the non-volatile aerosol fraction is measured. The Sky OPC measures the size distribution in the rage theoretically up to 32 μ m. Because of the inlet cut off diameter of D50=3 μ m we are using the 16 channel mode in the range of 250 nm - 2.5 μ m at 1 Hz resolution. In this presentation the IAGOS Aerosol package is characterized for pressure levels relevant for the planned application, down to cruising level of 150 hPa including the inlet system. In our aerosol lab we have tested the system against standard instrumentation with different aerosol test substances in a long duration test. Particle losses are characterized for the inlet system. In addition first results for airborne measurements are shown from a first field campaign.

  8. Liquid Flow in Biofilm Systems

    PubMed Central

    Stoodley, Paul; deBeer, Dirk; Lewandowski, Zbigniew

    1994-01-01

    A model biofilm consisting of Pseudomonas aeruginosa, Pseudomonas fluorescens, and Klebsiella pneumoniae was developed to study the relationships between structural heterogeneity and hydrodynamics. Local fluid velocity in the biofilm system was measured by a noninvasive method of particle image velocimetry, using confocal scanning laser microscopy. Velocity profiles were measured in conduit and porous medium reactors in the presence and absence of biofilm. Liquid flow was observed within biofilm channels; simultaneous imaging of the biofilm allowed the liquid velocity to be related to the physical structure of the biofilm. Images PMID:16349345

  9. Climate response of the South Asian monsoon system to anthropogenic aerosols

    SciTech Connect

    Ganguly, Dilip; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho

    2012-07-13

    The equilibrium climate response to the total effects (direct, indirect and semi-direct effects) of aerosols arising from anthropogenic and biomass burning emissions on the South Asian summer monsoon system is studied using a coupled atmosphere-slab ocean model. Our results suggest that anthropogenic and biomass burning aerosols generally induce a reduction in mean summer monsoon precipitation over most parts of the Indian subcontinent, strongest along the western coastline of the Indian peninsula and eastern Nepal region, but modest increases also occur over the north western part of the subcontinent. While most of the noted reduction in precipitation is triggered by increased emissions of aerosols from anthropogenic activities, modest increases in the north west are mostly associated with decreases in local emissions of aerosols from forest fire and grass fire sources. Anthropogenic aerosols from outside Asia also contribute to the overall reduction in precipitation but the dominant contribution comes from aerosol sources within Asia. Local emissions play a more important role in the total rainfall response to anthropogenic aerosol sources during the early monsoon period, whereas both local as well as remote emissions of aerosols play almost equally important roles during the later part of the monsoon period. While precipitation responses are primarily driven by local aerosol forcing, regional surface temperature changes over the region are strongly influenced by anthropogenic aerosols from sources further away (non-local changes). Changes in local anthropogenic organic and black carbon emissions by as much as a factor of two (preserving their ratio) produce the same basic signatures in the model's summer monsoon temperature and precipitation responses.

  10. Solid aerosol generator

    DOEpatents

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1992-03-17

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  11. Improved solid aerosol generator

    DOEpatents

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1988-07-19

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  12. Solid aerosol generator

    DOEpatents

    Prescott, Donald S.; Schober, Robert K.; Beller, John

    1992-01-01

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.

  13. Fast and Slow Responses of the South Asian Monsoon System to Anthropogenic Aerosols

    SciTech Connect

    Ganguly, Dilip; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho

    2012-09-25

    Using a global climate model with fully predictive aerosol life cycle, we investigate the fast and slow responses of the South Asian monsoon system to anthropogenic aerosol forcing. Our results show that the feedbacks associated with sea surface temperature (SST) change caused by aerosols play a more important role than the aerosol's direct impact on radiation, clouds and land surface (rapid adjustments) in shaping the total equilibrium climate response of the monsoon system to aerosol forcing. Inhomogeneous SST cooling caused by anthropogenic aerosols eventually reduces the meridional tropospheric temperature gradient and the easterly shear of zonal winds over the region, slowing down the local Hadley cell circulation, decreasing the northward moisture transport, and causing a reduction in precipitation over South Asia. Although total responses in precipitation are closer to the slow responses in general, the fast component dominates over land areas north of 25°N. Our results also show an east-west asymmetry in the fast responses to anthropogenic aerosols causing increases in precipitation west of 80°E but decreases east of it.

  14. The aerosol-monsoon climate system of Asia: A new paradigm

    NASA Astrophysics Data System (ADS)

    Lau, William K. M.

    2016-02-01

    This commentary is based on a series of recent lectures on aerosol-monsoon interactions I gave at the Beijing Normal University in August 2015. A main theme of the lectures is on a new paradigm of "An Aerosol-Monsoon-Climate-System", which posits that aerosol, like rainfall, cloud, and wind, is an integral component of the monsoon climate system, influencing monsoon weather and climate on all timescales. Here, salient issues discussed in my lectures and my personal perspective regarding interactions between atmospheric dynamics and aerosols from both natural and anthropogenic sources are summarized. My hope is that under this new paradigm, we can break down traditional disciplinary barriers, advance a deeper understanding of weather and climate in monsoon regions, as well as entrain a new generation of geoscientists to strive for a sustainable future for one of the most complex and challenging human-natural climate sub-system of the earth.

  15. Remote Sensing of Aerosol Over the Land from the Earth Observing System MODIS Instrument

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram; Tanre, Didier; Remer, Lorraine; Einaudi, Franco (Technical Monitor)

    2000-01-01

    On Dec 18, 1999, NASA launched the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument on the Earth Observing System (EOS) Terra mission, in a spectacular launch. The mission will provide morning (10:30 AM) global observations of aerosol and other related parameters. It will be followed a year later by a MODIS instrument on EOS Aqua for afternoon observations (1:30 PM). MODIS will measure aerosol over land and ocean with its eight 500 m and 250 m channels in the solar spectrum (0-41 to 2.2 micrometers). Over the land MODIS will measure the total column aerosol loading, and distinguish between submicron pollution particles and large soil particles. Standard daily products of resolution of ten kilometers and global mapped eight day and monthly products on a 1x1 degree global scale will be produced routinely and make available for no or small reproduction charge to the international community. Though the aerosol products will not be available everywhere over the land, it is expected that they will be useful for assessments of the presence, sources and transport of urban pollution, biomass burning aerosol, and desert dust. Other measurements from MODIS will supplement the aerosol information, e.g., land use change, urbanization, presence and magnitude of biomass burning fires, and effect of aerosol on cloud microphysics. Other instruments on Terra, e.g. Multi-angle Imaging SpectroRadiometer (MISR) and the Clouds and the Earth's Radiant Energy System (CERES), will also measure aerosol, its properties and radiative forcing in tandem with the MODIS measurements. During the Aqua period, there are plans to launch in 2003 the Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO) mission for global measurements of the aerosol vertical structure, and the PARASOL mission for aerosol characterization. Aqua-MODIS, PICASSO and PARASOL will fly in formation for detailed simultaneous characterization of the aerosol three-dimensional field, which

  16. Flow cytometer jet monitor system

    DOEpatents

    Van den Engh, Ger

    1997-01-01

    A direct jet monitor illuminates the jet of a flow cytometer in a monitor wavelength band which is substantially separate from the substance wavelength band. When a laser is used to cause fluorescence of the substance, it may be appropriate to use an infrared source to illuminate the jet and thus optically monitor the conditions within the jet through a CCD camera or the like. This optical monitoring may be provided to some type of controller or feedback system which automatically changes either the horizontal location of the jet, the point at which droplet separation occurs, or some other condition within the jet in order to maintain optimum conditions. The direct jet monitor may be operated simultaneously with the substance property sensing and analysis system so that continuous monitoring may be achieved without interfering with the substance data gathering and may be configured so as to allow the front of the analysis or free fall area to be unobstructed during processing.

  17. Addition of Tropospheric Chemistry and Aerosols to the NCAR Community Climate System Model

    SciTech Connect

    Cameron-Smith, P; Lamarque, J; Connell, P; Chuang, C; Rotman, D; Taylor, J

    2005-11-14

    Atmospheric chemistry and aerosols have several important roles in climate change. They affect the Earth's radiative balance directly: cooling the earth by scattering sunlight (aerosols) and warming the Earth by trapping the Earth's thermal radiation (methane, ozone, nitrous oxide, and CFCs are greenhouse gases). Atmospheric chemistry and aerosols also impact many other parts of the climate system: modifying cloud properties (aerosols can be cloud condensation nuclei), fertilizing the biosphere (nitrogen species and soil dust), and damaging the biosphere (acid rain and ozone damage). In order to understand and quantify the effects of atmospheric chemistry and aerosols on the climate and the biosphere in the future, it is necessary to incorporate atmospheric chemistry and aerosols into state-of-the-art climate system models. We have taken several important strides down that path. Working with the latest NCAR Community Climate System Model (CCSM), we have incorporated a state-of-the-art atmospheric chemistry model to simulate tropospheric ozone. Ozone is not just a greenhouse gas, it damages biological systems including lungs, tires, and crops. Ozone chemistry is also central to the oxidizing power of the atmosphere, which destroys a lot of pollutants in the atmosphere (which is a good thing). We have also implemented a fast chemical mechanism that has high fidelity with the full mechanism, for significantly reduced computational cost (to facilitate millennium scale simulations). Sulfate aerosols have a strong effect on climate by reflecting sunlight and modifying cloud properties. So in order to simulate the sulfur cycle more fully in CCSM simulations, we have linked the formation of sulfate aerosols to the oxidizing power of the atmosphere calculated by the ozone mechanisms, and to dimethyl sulfide emissions from the ocean ecosystem in the model. Since the impact of sulfate aerosols depends on the relative abundance of other aerosols in the atmosphere, we also

  18. Evaluation of Meteorological and Aerosol Sensing with small Unmanned Aerial Systems

    NASA Astrophysics Data System (ADS)

    Claussen, Johanna; Möhler, Ottmar; Leisner, Thomas; Brooks, Ian; Norris, Sarah; Brooks, Barbara; Hill, Martin; Haunold, Werner; Schrod, Jann; Danielczok, Anja

    2013-04-01

    Atmospheric aerosols have a large impact on the climate system due to their influence on the global radiation budget. Local aerosol sources such as vegetation, (bare) soil or industrial sites have to be quantified with high resolution data to validate aerosol transport models and improve the input for high resolution weather models. Our goal is to evaluate the use of Unmanned Aerial Systems (UAS) as a method for acquisition of high resolution meteorological and aerosol data. During the INUIT measurement campaign in August 2012 at mount Großer Feldberg near Frankfurt, Germany, several flights with different sensor packages were carried out. We measured basic meteorological parameters such as temperature, relative humidity and air pressure with miniaturized onboard sensors. In addition, the Compact Lightweight Aerosol Spectrometer Probe (CLASP) for aerosol size distribution measurement or the Electrostatic Aerosol Collector (EAC) for aerosol sample collection was installed on board. CLASP measures aerosol particles with diameters from 0.17 μm to 9.5 μm in up to 32 channels at a frequency of 10 Hz. The EAC collects air samples at 2 l/min onto a sample holder. After the flight the ice nuclei on the sample holder are activated and counted in the isothermal static diffusion chamber FRIDGE. The results from the INUIT campaign and additional calibration laboratory measurements show that UAS are a valuable platform for miniaturized sensors. The number of ice nuclei was determined with the EAC at 200m above ground level and compared to the reference measurement on the ground.

  19. A laboratory scale supersonic combustive flow system

    SciTech Connect

    Sams, E.C.; Zerkle, D.K.; Fry, H.A.; Wantuck, P.J.

    1995-02-01

    A laboratory scale supersonic flow system [Combustive Flow System (CFS)] which utilizes the gaseous products of methane-air and/or liquid fuel-air combustion has been assembled to provide a propulsion type exhaust flow field for various applications. Such applications include providing a testbed for the study of planar two-dimensional nozzle flow fields with chemistry, three-dimensional flow field mixing near the exit of rectangular nozzles, benchmarking the predictive capability of various computational fluid dynamic codes, and the development and testing of advanced diagnostic techniques. This paper will provide a detailed description of the flow system and data related to its operation.

  20. Impact of Aerosols on Atmospheric Attenuation Loss in Central Receiver Systems: Preprint

    SciTech Connect

    Sengupta, M.; Wagner, M. J.

    2011-08-01

    Atmospheric attenuation loss between the heliostat field and receiver has been recognized as a significant source of loss in Central Receiver Systems. In clear sky situations, extinction of Direct Normal Irradiance (DNI) is primarily by aerosols in the atmosphere. When aerosol loading is high close to the surface the attenuation loss between heliostat and receivers is significantly influenced by the amount of aerosols present on a particular day. This study relates measured DNI to aerosol optical depths close to the surface of the earth. The model developed in the paper uses only measured DNI to estimate the attenuation between heliostat and receiver in a central receiver system. The requirement that only a DNI measurement is available potentially makes the model a candidate for widespread use.

  1. Comparison of two in vitro systems to assess cellular effects of nanoparticles-containing aerosols

    PubMed Central

    Fröhlich, Eleonore; Bonstingl, Gudrun; Höfler, Anita; Meindl, Claudia; Leitinger, Gerd; Pieber, Thomas R.; Roblegg, Eva

    2013-01-01

    Inhalation treatment with nanoparticle containing aerosols appears a promising new therapeutic option but new formulations have to be assessed for efficacy and toxicity. We evaluated the utility of a VITROCELL®6 PT-CF + PARI LC SPRINT® Baby Nebulizer (PARI BOY) system compared with a conventional MicroSprayer. A549 cells were cultured in the air–liquid interface, exposed to nanoparticle aerosols and characterized by measurement of transepithelial electrical resistance and staining for tight junction proteins. Deposition and distribution rates of polystyrene particles and of carbon nanotubes on the cells were assessed. In addition, cytotoxicity of aerosols containing polystyrene particles was compared with cytotoxicity of polystyrene particles in suspension tested in submersed cultures. Exposure by itself in both exposure systems did not damage the cells. Deposition rates of aerosolized polystyrene particles were about 700 times and that of carbon nanotubes about 4 times higher in the MicroSprayer than in the VITROCELL®6 PT-CF system. Cytotoxicity of amine-functionalized polystyrene nanoparticles was significantly higher when applied as an aerosol on cell cultured in air–liquid interface culture compared with nanoparticle suspensions tested in submersed culture. The higher cytotoxicity of aerosolized nanoparticles underscores the importance of relevant exposure systems. PMID:22906573

  2. Current and Future Applications of the GEOS-5 Aerosol Modeling System

    NASA Technical Reports Server (NTRS)

    Colarco, Peter R.; Silva, Arlindo M Da; Burchard-Marchant, Virginie J.; Darmenov, Anton S.; Govindaraju, Ravi C.; Randles, Cynthia A.; Aquila, Valentina; Nowottnick, Edward Paul; Bian, Huisheng

    2013-01-01

    The presentation summarizes current and proposed activities for the GEOS-5 aerosol modeling system. Activities discussed include (i) forecasting and event simulation, (ii) observation simulation, (iii) aerosol-chemistry-climate applications, and (iv) future activities. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocenter website, after the meeting.

  3. Aerosol Layering Characterization Near the Gobi Desert by a Double Polarization Lidar System

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Boselli, A.; Sannino, A.; Song, C.; Spinelli, N.; Wang, X.

    2016-06-01

    In order to carry out 4-D (space and time) analysis of the atmospheric aerosol distribution and to make a characterization of their properties and time evolution, a transportable multi-wavelength, Elastic/Raman scanning lidar system with angular scanning capability has been realized. The system uses a diode pumped Nd:YAG laser source, specifically designed for this device, and a receiving systems able to detect elastic signals at 355, 532 and 1064 nm and Raman signals at 386, 407 and 607 nm. It also allows to perform aerosol depolarization measurements at both 355nm and 532nm. A first measurement campaign has been carried out in Dunhuang, North-West of China, in the region of the Gobi desert with the aims to study and characterize desert dust at source. Optical properties of aerosol layers developing in the atmosphere have been analyzed and lidar data are discussed in terms of profiles of aerosol backscatter coefficient at 355nm, 532nm, aerosol extinction coefficient at 355nm, aerosol depolarization ratio at 355nm and 532nm and water vapor mixing ratio. Depolarization ratio measured simultaneously at two wavelengths allowed also to study its dependence on the wavelength.

  4. Numerical modeling of species transport in turbulent flow and experimental study on aerosol sampling

    NASA Astrophysics Data System (ADS)

    Vijayaraghavan, Vishnu Karthik

    Numerical simulations were performed to study the turbulent mixing of a scalar species in straight tube, single and double elbow flow configurations. Different Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulation (LES) models were used to model the turbulence in the flow. Conventional and dynamic Smagorinsky sub-grid scale models were used for the LES simulations. Wall functions were used to resolve the near wall boundary layer. These simulations were run with both two-dimensional and three-dimensional geometries. The velocity and tracer gas concentration Coefficient of Variations were compared with experimental results. The results from the LES simulations compared better with experimental results than the results from the RANS simulations. The level of mixing downstream of a S-shaped double elbow was higher than either the single elbow or the U-shaped double elbow due to the presence of counter rotating vortices. Penetration of neutralized and non-neutralized aerosol particles through three different types of tubing was studied. The tubing used included standard PVC pipes, aluminum conduit and flexible vacuum hose. Penetration through the aluminum conduit was unaffected by the presence or absence of charge neutralization, whereas particle penetrations through the PVC pipe and the flexible hosing were affected by the amount of particle charge. The electric field in a space enclosed by a solid conductor is zero. Therefore charged particles within the conducting aluminum conduit do not experience any force due to ambient electric fields, whereas the charged particles within the non-conducting PVC pipe and flexible hose experience forces due to the ambient electric fields. This increases the deposition of charged particles compared to neutralized particles within the 1.5" PVC tube and 1.5" flexible hose. Deposition 2001a (McFarland et al. 2001) software was used to predict the penetration through transport lines. The prediction from the software compared

  5. ECOLOGICAL EFFECTS OF AEROSOL DRIFT FROM A SALTWATER COOLING SYSTEM

    EPA Science Inventory

    The local terrestrial effects of salt aerosol drift from powered spray modules and a mechanical draft cooling tower at Turkey Point, Florida were evaluated through field and controlled exposure studies. Indigenous vegetation, soil and fresh water were sampled over a year long per...

  6. Real-Time Detection Method And System For Identifying Individual Aerosol Particles

    DOEpatents

    Gard, Eric Evan; Fergenson, David Philip

    2005-10-25

    A method and system of identifying individual aerosol particles in real time. Sample aerosol particles are compared against and identified with substantially matching known particle types by producing positive and negative test spectra of an individual aerosol particle using a bipolar single particle mass spectrometer. Each test spectrum is compared to spectra of the same respective polarity in a database of predetermined positive and negative spectra for known particle types and a set of substantially matching spectra is obtained. Finally the identity of the individual aerosol particle is determined from the set of substantially matching spectra by determining a best matching one of the known particle types having both a substantially matching positive spectrum and a substantially matching negative spectrum associated with the best matching known particle type.

  7. High-latitude stratospheric aerosols measured by the SAM II satellite system in 1978 and 1979

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.; Chu, W. P.; Mcmaster, L. R.; Grams, G. W.; Hamill, P.; Steele, H. M.; Swissler, T. J.; Herman, B. M.; Pepin, T. J.; Russell, P. B.

    1981-01-01

    Results of the first year of data collection by the SAM (Stratospheric Aerosol Measurement) II satellite system are presented. Almost 10,000 profiles of stratospheric aerosol extinction in the Arctic and Antarctic regions are used to construct plots of weekly averaged aerosol extinction versus altitude and time and stratospheric optical depth versus time. Corresponding temperature fields are presented. These data show striking similarities in the aerosol behavior for corresponding seasons. Wintertime polar stratospheric clouds that are strongly correlated with temperature are documented. They are much more prevalent in the Antarctic stratosphere during the cold austral winter and increase the stratospheric optical depths by as much as an order of magnitude for a period of about 2 months. These clouds might represent a sink for stratospheric water vapor and must be considered in the radiative budget for this region and time.

  8. [Development of a photoacoustic spectroscopy system for the measurement of absorption coefficient of atmospheric aerosols].

    PubMed

    Liu, Qiang; Niu, Ming-Sheng; Wang, Gui-Shi; Cao, Zhen-Song; Liu, Kun; Chen, Wei-Dong; Gao, Xiao-Ming

    2013-07-01

    In the present paper, the authors focus on the effect of the resonance frequency shift due to the changes in temperature and humidity on the PA signal, present several methods to control the noise derived form gas flow and vibration from the sampling pump. Based on the efforts mentioned above, a detection limit of 1.4 x 10(-8) W x cm(-1) x Hz(-1/2) was achieved for the measurement of atmospheric aerosols absorption coefficient. During the experiments, the PA cell was calibrated with the absorption of standard NO2 gas at 532 nm and the atmospheric aerosols were measured continuously. The measurement results show that the PAS is suitable for the real-time measurement of the absorption coefficient of atmospheric aerosols in their natural suspended state. PMID:24059163

  9. Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system.

    PubMed

    Seinfeld, John H; Bretherton, Christopher; Carslaw, Kenneth S; Coe, Hugh; DeMott, Paul J; Dunlea, Edward J; Feingold, Graham; Ghan, Steven; Guenther, Alex B; Kahn, Ralph; Kraucunas, Ian; Kreidenweis, Sonia M; Molina, Mario J; Nenes, Athanasios; Penner, Joyce E; Prather, Kimberly A; Ramanathan, V; Ramaswamy, Venkatachalam; Rasch, Philip J; Ravishankara, A R; Rosenfeld, Daniel; Stephens, Graeme; Wood, Robert

    2016-05-24

    The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth's clouds is the most uncertain component of the overall global radiative forcing from preindustrial time. General circulation models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and aerosol-cloud radiative effects carries large uncertainties that directly affect GCM predictions, such as climate sensitivity. Predictions are hampered by the large range of scales of interaction between various components that need to be captured. Observation systems (remote sensing, in situ) are increasingly being used to constrain predictions, but significant challenges exist, to some extent because of the large range of scales and the fact that the various measuring systems tend to address different scales. Fine-scale models represent clouds, aerosols, and aerosol-cloud interactions with high fidelity but do not include interactions with the larger scale and are therefore limited from a climatic point of view. We suggest strategies for improving estimates of aerosol-cloud relationships in climate models, for new remote sensing and in situ measurements, and for quantifying and reducing model uncertainty. PMID:27222566

  10. Lidar System for Airborne Measurement of Clouds and Aerosols

    NASA Technical Reports Server (NTRS)

    McGill, Matthew; Scott, V. Stanley; Izquierdo, Luis Ramos; Marzouk, Joe

    2008-01-01

    A lidar system for measuring optical properties of clouds and aerosols at three wavelengths is depicted. The laser transmitter is based on a Nd:YVO4 laser crystal pumped by light coupled to the crystal via optical fibers from laser diodes that are located away from the crystal to aid in dissipating the heat generated in the diodes and their drive circuits. The output of the Nd:YVO4 crystal has a wavelength of 1064 nm, and is made to pass through frequency-doubling and frequency-tripling crystals. As a result, the net laser output is a collinear superposition of beams at wavelengths of 1064, 532, and 355 nm. The laser operates at a pulse-repetition rate of 5 kHz, emitting per-pulse energies of 50 microJ at 1064 nm, 25 microJ at 532 nm and 50 microJ at 355 nm. An important feature of this system is an integrating sphere located between the laser output and the laser beam expander lenses. The integrating sphere collects light scattered from the lenses. Three energy-monitor detectors are located at ports inside the integrating sphere. Each of these detectors is equipped with filters such that the laser output energy is measured independently for each wavelength. The laser output energy is measured on each pulse to enable the most accurate calibration possible. The 1064-nm and 532-nm photodetectors are, more specifically, single photon-counting modules (SPCMs). When used at 1064 nm, these detectors have approximately 3% quantum efficiency and low thermal noise (fewer than 200 counts per second). When used at 532 nm, the SPCMs have quantum efficiency of about 60%. The photodetector for the 355-nm channel is a photon-counting photomultiplier tube having a quantum efficiency of about 20%. The use of photon-counting detectors is made feasible by the low laser pulse energy. The main advantage of photon-counting is ease of inversion of data without need for complicated calibration schemes like those necessary for analog detectors. The disadvantage of photon-counting detectors

  11. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    NASA Astrophysics Data System (ADS)

    Palm, Brett B.; Campuzano-Jost, Pedro; Ortega, Amber M.; Day, Douglas A.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Hunter, James F.; Cross, Eben S.; Kroll, Jesse H.; Peng, Zhe; Brune, William H.; Jimenez, Jose L.

    2016-03-01

    An oxidation flow reactor (OFR) is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen-Rocky Mountain Biogenic Aerosol Study) field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed for semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs) onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m-3 when LVOC fate corrected) compared to daytime (average 0.9 µg m-3 when LVOC fate corrected), with maximum formation observed at 0.4-1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (> 10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production of small oxidized organic

  12. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    DOE PAGESBeta

    Palm, Brett B.; Campuzano-Jost, Pedro; Ortega, Amber M.; Day, Douglas A.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Hunter, James F.; Cross, Eben S.; et al

    2016-03-08

    An oxidation flow reactor (OFR) is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen–Rocky Mountain Biogenic Aerosol Study) field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed formore » semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs) onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m–3 when LVOC fate corrected) compared to daytime (average 0.9 µg m–3 when LVOC fate corrected), with maximum formation observed at 0.4–1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (>10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production of small

  13. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    DOE PAGESBeta

    Palm, Brett B.; Campuzano-Jost, Pedro; Ortega, Amber M.; Day, Douglas A.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Hunter, James F.; Cross, Eben S.; et al

    2016-03-08

    An oxidation flow reactor (OFR) is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen–Rocky Mountain Biogenic Aerosol Study) field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed formore » semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs) onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m−3 when LVOC fate corrected) compared to daytime (average 0.9 µg m−3 when LVOC fate corrected), with maximum formation observed at 0.4–1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (> 10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production of

  14. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    SciTech Connect

    Palm, Brett B.; Campuzano-Jost, Pedro; Ortega, Amber M.; Day, Douglas A.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Hunter, James F.; Cross, Eben S.; Kroll, Jesse H.; Peng, Zhe; Brune, William H.; Jimenez, Jose L.

    2016-01-01

    An oxidation flow reactor (OFR) is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen–Rocky Mountain Biogenic Aerosol Study) field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed for semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs) onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m−3 when LVOC fate corrected) compared to daytime (average 0.9 µg m−3 when LVOC fate corrected), with maximum formation observed at 0.4–1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (> 10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the

  15. Flow and transport in hierarchically fractured systems

    SciTech Connect

    Karasaki, K.

    1993-01-01

    Preliminary results indicate that flow in the saturated zone at Yucca Mountain is controlled by fractures. A current conceptual model assumes that the flow in the fracture system can be approximately by a three-dimensionally interconnected network of linear conduits. The overall flow system of rocks at Yucca Mountain is considered to consist of hierarchically structured heterogeneous fracture systems of multiple scales. A case study suggests that it is more appropriate to use the flow parameters of the large fracture system for predicting the first arrival time, rather than using the bulk average parameters of the total system.

  16. Flow and transport in hierarchically fractured systems

    SciTech Connect

    Karasaki, K.

    1993-12-31

    Preliminary results indicate that flow in the saturated zone at Yucca Mountain is controlled by fractures. A current conceptual model assumes that the flow in the fracture system can be approximated by a three-dimensionally interconnected network of linear conduits. The overall flow system of rocks at Yucca Mountain is considered to consist of hierarchically structured heterogeneous fracture systems of multiple scales. A case study suggests that it is more appropriate to use the flow parameters of the large fracture system for predicting the first arrival time, rather than using the bulk average parameters of the total system.

  17. A single-particle characterization of a mobile Versatile Aerosol Concentration Enrichment System for exposure studies

    PubMed Central

    Freney, Evelyn J; Heal, Mathew R; Donovan, Robert J; Mills, Nicholas L; Donaldson, Kenneth; Newby, David E; Fokkens, Paul HB; Cassee, Flemming R

    2006-01-01

    Background An Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) was used to investigate the size and chemical composition of fine concentrated ambient particles (CAPs) in the size range 0.2–2.6 μm produced by a Versatile Aerosol Concentration Enrichment System (VACES) contained within the Mobile Ambient Particle Concentrator Exposure Laboratory (MAPCEL). The data were collected during a study of human exposure to CAPs, in Edinburgh (UK), in February-March 2004. The air flow prior to, and post, concentration in the VACES was sampled in turn into the ATOFMS, which provides simultaneous size and positive and negative mass spectral data on individual fine particles. Results The particle size distribution was unaltered by the concentrator over the size range 0.2–2.6 μm, with an average enrichment factor during this study of ~5 (after dilution of the final air stream). The mass spectra from single particles were objectively grouped into 20 clusters using the multivariate K-means algorithm and then further grouped manually, according to similarity in composition and time sequence, into 8 main clusters. The particle ensemble was dominated by pure and reacted sea salt and other coarse inorganic dusts (as a consequence of the prevailing maritime-source climatology during the study), with relatively minor contributions from carbonaceous and secondary material. Very minor variations in particle composition were noted pre- and post-particle concentration, but overall there was no evidence of any significant change in particle composition. Conclusion These results confirm, via single particle analysis, the preservation of the size distribution and chemical composition of fine ambient PM in the size range 0.2–2.6 μm after passage through the VACES concentration instrumentation. PMID:16723024

  18. Computer-automated silica aerosol generator and animal inhalation exposure system

    PubMed Central

    McKinney, Walter; Chen, Bean; Schwegler-Berry, Diane; Frazer, Dave G.

    2015-01-01

    Inhalation exposure systems are necessary tools for determining the dose response relationship of inhaled toxicants under a variety of exposure conditions. The objective of this study was to develop an automated computer controlled system to expose small laboratory animals to precise concentrations of uniformly dispersed airborne silica particles. An acoustical aerosol generator was developed which was capable of re-suspending particles from bulk powder. The aerosolized silica output from the generator was introduced into the throat of a venturi tube. The turbulent high-velocity air stream within the venturi tube increased the dispersion of the re-suspended powder. That aerosol was then used to expose small laboratory animals to constant aerosol concentrations, up to 20mg/m3, for durations lasting up to 8h. Particle distribution and morphology of the silica aerosol delivered to the exposure chamber were characterized to verify that a fully dispersed and respirable aerosol was being produced. The inhalation exposure system utilized a combination of airflow controllers, particle monitors, data acquisition devices and custom software with automatic feedback control to achieve constant and repeatable exposure environments. The automatic control algorithm was capable of maintaining median aerosol concentrations to within ±0.2 mg/m3 of a user selected target concentration during exposures lasting from 2 to 8 h. The system was able to reach 95% of the desired target value in <10min during the beginning phase of an exposure. This exposure system provided a highly automated tool for conducting inhalation toxicology studies involving silica particles. PMID:23796015

  19. Secondary organic aerosol formation and primary organic aerosol oxidation from biomass-burning smoke in a flow reactor during FLAME-3

    NASA Astrophysics Data System (ADS)

    Ortega, A. M.; Day, D. A.; Cubison, M. J.; Brune, W. H.; Bon, D.; de Gouw, J. A.; Jimenez, J. L.

    2013-11-01

    We report the physical and chemical effects of photochemically aging dilute biomass-burning smoke. A "potential aerosol mass" (PAM) flow reactor was used with analysis by a high-resolution aerosol mass spectrometer and a proton-transfer-reaction ion-trap mass spectrometer during the FLAME-3 campaign. Hydroxyl (OH) radical concentrations in the reactor reached up to ~1000 times average tropospheric levels, producing effective OH exposures equivalent to up to 5 days of aging in the atmosphere, and allowing for us to extend the investigation of smoke aging beyond the oxidation levels achieved in traditional smog chambers. Volatile organic compound (VOC) observations show aromatics and terpenes decrease with aging, while formic acid and other unidentified oxidation products increase. Unidentified gas-phase oxidation products, previously observed in atmospheric and laboratory measurements, were observed here, including evidence of multiple generations of photochemistry. Substantial new organic aerosol (OA) mass ("net SOA"; secondary OA) was observed from aging biomass-burning smoke, resulting in total OA average of 1.42 ± 0.36 times the initial primary OA (POA) after oxidation. This study confirms that the net-SOA-to-POA ratio of biomass-burning smoke is far lower on average than that observed for urban emissions. Although most fuels were very reproducible, significant differences were observed among the biomasses, with some fuels resulting in a doubling of the OA mass, while for others a very small increase or even a decrease was observed. Net SOA formation in the photochemical reactor increased with OH exposure (OHexp), typically peaking around three days of equivalent atmospheric photochemical age (OHexp~3.9 × 1011 molecules cm-3 s), then leveling off at higher exposures. The amount of additional OA mass added from aging is positively correlated with initial POA concentration, but not with the total VOC concentration or the concentration of known SOA precursors

  20. Internal-flow systems for aircraft

    NASA Technical Reports Server (NTRS)

    Rogallo, F M

    1941-01-01

    An investigation has been made to determine efficient arrangements for an internal-flow system of an aircraft when such a system operates by itself or in combination with other flow systems. The investigation included a theoretical treatment of the problem and tests in the NACA 5-foot vertical wind tunnel of inlet and outlet openings in a flat plate and in a wing.

  1. Code System to Calculate Particle Penetration Through Aerosol Transport Lines.

    1999-07-14

    Version 00 Distribution is restricted to US Government Agencies and Their Contractors Only. DEPOSITION1.03 is an interactive software program which was developed for the design and analysis of aerosol transport lines. Models are presented for calculating aerosol particle penetration through straight tubes of arbitrary orientation, inlets, and elbows. An expression to calculate effective depositional velocities of particles on tube walls is derived. The concept of maximum penetration is introduced, which is the maximum possible penetrationmore » through a sampling line connecting any two points in a three-dimensional space. A procedure to predict optimum tube diameter for an existing transport line is developed. Note that there is a discrepancy in this package which includes the DEPOSITION 1.03 executable and the DEPOSITION 2.0 report. RSICC was unable to obtain other executables or reports.« less

  2. Dual-aureole and sun spectrometer system for airborne measurements of aerosol optical properties.

    PubMed

    Zieger, Paul; Ruhtz, Thomas; Preusker, Rene; Fischer, Jürgen

    2007-12-10

    We have designed an airborne spectrometer system for the simultaneous measurement of the direct sun irradiance and the aureole radiance in two different solid angles. The high-resolution spectral radiation measurements are used to derive vertical profiles of aerosol optical properties. Combined measurements in two solid angles provide better information about the aerosol type without additional and elaborate measuring geometries. It is even possible to discriminate between absorbing and nonabsorbing aerosol types. Furthermore, they allow to apply additional calibration methods and simplify the detection of contaminated data (e.g., by thin cirrus clouds). For the characterization of the detected aerosol type a new index is introduced that is the slope of the aerosol phase function in the forward scattering region. The instrumentation is a flexible modular setup, which has already been successfully applied in airborne and ground-based field campaigns. We describe the setup as well as the calibration of the instrument. In addition, example vertical profiles of aerosol optical properties--including the aureole measurements--are shown and discussed. PMID:18071387

  3. Characterization of a Quadrotor Unmanned Aircraft System for Aerosol-Particle-Concentration Measurements.

    PubMed

    Brady, James M; Stokes, M Dale; Bonnardel, Jim; Bertram, Timothy H

    2016-02-01

    High-spatial-resolution, near-surface vertical profiling of atmospheric chemical composition is currently limited by the availability of experimental platforms that can sample in constrained environments. As a result, measurements of near-surface gradients in trace gas and aerosol particle concentrations have been limited to studies conducted from fixed location towers or tethered balloons. Here, we explore the utility of a quadrotor unmanned aircraft system (UAS) as a sampling platform to measure vertical and horizontal concentration gradients of trace gases and aerosol particles at high spatial resolution (1 m) within the mixed layer (0-100 m). A 3D Robotics Iris+ autonomous quadrotor UAS was outfitted with a sensor package consisting of a two-channel aerosol optical particle counter and a CO2 sensor. The UAS demonstrated high precision in both vertical (±0.5 m) and horizontal positions (±1 m), highlighting the potential utility of quadrotor UAS drones for aerosol- and trace-gas measurements within complex terrain, such as the urban environment, forest canopies, and above difficult-to-access areas such as breaking surf. Vertical profiles of aerosol particle number concentrations, acquired from flights conducted along the California coastline, were used to constrain sea-spray aerosol-emission rates from coastal wave breaking. PMID:26730457

  4. Layered Systems Under Shear Flow

    NASA Astrophysics Data System (ADS)

    Svenšek, Daniel; Brand, Helmut R.

    We discuss and review a generalization of the usual hydrodynamic description of smectic A liquid crystals motivated by the experimentally observed shear-induced destabilization and reorientation of smectic A like systems. We include both the smectic layering (via the layer displacement u and the layer normal hat{p}) and the director hat{n} of the underlying nematic order in our macroscopic hydrodynamic description and allow both directions to differ in non equilibrium situations. In a homeotropically aligned sample the nematic director couples to an applied simple shear, whereas the smectic layering stays unchanged. This difference leads to a finite (but usually small) angle between hat{n} and hat{p}, which we find to be equivalent to an effective dilatation of the layers. This effective dilatation leads, above a certain threshold, to an undulation instability of the layers with a wave vector parallel to the vorticity direction of the shear flow. We include the couplings of the velocity field with the order parameters for orientational and positional order and show how the order parameters interact with the undulation instability. We explore the influence of the magnitude of various material parameters on the instability. Comparing our results to available experimental results and molecular dynamic simulations, we find good qualitative agreement for the first instability. In addition, we discuss pathways to higher instabilities leading to the formation of onions (multilamellar vesicles) via cylindrical structures and/or the break-up of layers via large amplitude undulations.

  5. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    NASA Astrophysics Data System (ADS)

    Palm, B. B.; Campuzano-Jost, P.; Ortega, A. M.; Day, D. A.; Kaser, L.; Jud, W.; Karl, T.; Hansel, A.; Hunter, J. F.; Cross, E. S.; Kroll, J. H.; Peng, Z.; Brune, W. H.; Jimenez, J. L.

    2015-11-01

    Ambient air was oxidized by OH radicals in an oxidation flow reactor (OFR) located in a montane pine forest during the BEACHON-RoMBAS campaign to study biogenic secondary organic aerosol (SOA) formation and aging. High OH concentrations and short residence times allowed for semi-continuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative time scales of condensation of low volatility organic compounds (LVOCs) onto particles, condensational loss to the walls, and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 4 μg m-3 when LVOC fate corrected) compared to daytime (average 1 μg m-3 when LVOC fate corrected), with maximum formation observed at 0.4-1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene + p-cymene concentrations, including a substantial increase just after sunrise at 07:00 LT. Higher photochemical aging (> 10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production of small oxidized organic compounds, and net production at lower ages followed by net consumption of terpenoid oxidation products as photochemical age increased. New particle formation was observed in the reactor after oxidation, especially during times when precursor gas concentrations and SOA formation were largest. Approximately 6 times more SOA was formed in the reactor from OH oxidation than

  6. Studies of Ice Nucleating Aerosol Particles in Arctic Cloud Systems

    NASA Technical Reports Server (NTRS)

    Rogers, David C.; DeMott, Paul J.; Kreidenweis, Sonia M.

    2001-01-01

    The focus of this research is to improve the understanding of ice nucleating aerosol particles (IN) and the role they play in ice formation in Arctic clouds. IN are important for global climate issues in a variety of ways. The primary effect is their role in determining the phase (liquid or solid) of cloud particles. The microscale impact is on cloud particle size, growth rate, shape, fall speed, concentration, radiative properties, and scavenging of gases and aerosols. On a larger scale, ice formation affects the development of precipitation (rate, amount, type, and distribution), latent heat release (rate and altitude), ambient humidity, the persistence of clouds, and cloud albedo. The overall goals of our FIRE 3 research are to characterize the concentrations and variability of Arctic IN during the winter-spring transition, to compare IN measurements with ice concentrations in Arctic clouds, and to examine selected IN samples for particle morphology and chemical there are distinguishable chemical signatures. The results can be combined with other measurements of aerosols, gaseous species, and cloud characteristics in order to understand the processes that determine the phase and concentration of cloud particles.

  7. Development of a preparation system for the radiocarbon analysis of organic carbon in carbonaceous aerosols in China

    NASA Astrophysics Data System (ADS)

    Zhang, Y. L.; Liu, D.; Shen, C. D.; Ding, P.; Zhang, G.

    2010-09-01

    Carbonaceous aerosols comprising a large fraction of elemental carbon (EC) and organic carbon (OC) are considered to affect both global climate and human health. Radiocarbon measurements have been proved to be a useful isotopic tracer for distinguishing contemporary and fossil emissions. An optimized system of a two-step thermal preparation system for radiocarbon ( 14C) measurement of OC/TC is firstly established in China. In this system, OC/TC are converted into carbon dioxide under a pure oxygen flow at 340 °C/650 °C and then reduced to graphite for AMS target using the method of zinc reduction. Afterwards, radiocarbon measurements of the targets performed by the NEC Compact AMS System at the Institute of Heavy Ion Physics, Peking University. The measured results for estimated reference martial including HOx I, HOx II and IAEA-C6 are consistent with internationally accepted values. The radiocarbon-based source appointment of carbonaceous aerosols in China would be much more convenient and faster with the preparation system developed in this work.

  8. X-RAY POWDER DIFFRACTION SYSTEM FOR CHEMICAL SPECIATION OF PARTICULATE AEROSOL SAMPLES

    EPA Science Inventory

    An x-ray powder diffraction system has been developed for the automated measurement and analysis of particulate aerosol samples. The system is optimized to process samples with particle loadings of about 100 micrograms/sq cm which are acquired with dichotomous air samplers. A pos...

  9. Performance of High Flow Rate Personal Respirable Samplers When Challenged with Mineral Aerosols of Different Particle Size Distributions.

    PubMed

    Stacey, Peter; Thorpe, Andrew; Echt, Alan

    2016-05-01

    It is thought that the performance of respirable samplers may vary when exposed to dust aerosols with different particle sizes and wind speeds. This study investigated the performance of the GK 4.16 (RASCAL), GK 2.69, PPI 8, and FSP 10, high flow rate personal samplers when exposed to aerosols of mineral dust in a wind tunnel at two different wind speeds (1 and 2 m s(-1)) and orientations (towards and side-on to the source of emission). The mass median aerodynamic diameter of four aerosolized test dusts ranged from 8 to 25 µm with geometric standard deviations from 1.6 to 2 µm. The performance of each sampler type was compared with that of the SIMPEDS (Higgins-Dewell design) sampler. There was slight evidence to suggest that the performance of the FSP 10 is affected by the direction of the inlet relative to the air flow, although this was not significant when most respirable dust concentrations were compared, possibly due to the variability of paired dust concentration results. The GK 2.69, RASCAL, and PPI 8 samplers had similar performances, although the results when side-on to the emission source were generally slightly lower than the SIMPEDS. Despite slight differences between respirable dust concentrations the respirable crystalline silica values were not significantly different from the SIMPEDS. The GK family of cyclones obtained most precise results and more closely matched the SIMPEDS. A comparison with dust concentration results from previous calm air chamber studies (where wind speeds were < 0.4 m s(-1)) found that the relative performance between samplers was similar to those observed in this work indicating consistent performance relative to the SIMPEDS in both calm and moving air. PMID:26865560

  10. Performance of High Flow Rate Personal Respirable Samplers When Challenged with Mineral Aerosols of Different Particle Size Distributions

    PubMed Central

    Stacey, Peter; Thorpe, Andrew; Echt, Alan

    2016-01-01

    It is thought that the performance of respirable samplers may vary when exposed to dust aerosols with different particle sizes and wind speeds. This study investigated the performance of the GK 4.16 (RASCAL), GK 2.69, PPI 8, and FSP 10, high flow rate personal samplers when exposed to aerosols of mineral dust in a wind tunnel at two different wind speeds (1 and 2 m s−1) and orientations (towards and side-on to the source of emission). The mass median aerodynamic diameter of four aerosolized test dusts ranged from 8 to 25 µm with geometric standard deviations from 1.6 to 2 µm. The performance of each sampler type was compared with that of the SIMPEDS (Higgins–Dewell design) sampler. There was slight evidence to suggest that the performance of the FSP 10 is affected by the direction of the inlet relative to the air flow, although this was not significant when most respirable dust concentrations were compared, possibly due to the variability of paired dust concentration results. The GK 2.69, RASCAL, and PPI 8 samplers had similar performances, although the results when side-on to the emission source were generally slightly lower than the SIMPEDS. Despite slight differences between respirable dust concentrations the respirable crystalline silica values were not significantly different from the SIMPEDS. The GK family of cyclones obtained most precise results and more closely matched the SIMPEDS. A comparison with dust concentration results from previous calm air chamber studies (where wind speeds were < 0.4 m s−1) found that the relative performance between samplers was similar to those observed in this work indicating consistent performance relative to the SIMPEDS in both calm and moving air. PMID:26865560

  11. Chronic air-flow limitation does not increase respiratory epithelial permeability assessed by aerosolized solute, but smoking does

    SciTech Connect

    Huchon, G.J.; Russell, J.A.; Barritault, L.G.; Lipavsky, A.; Murray, J.F.

    1984-09-01

    To determine the separate influences of smoking and severe air-flow limitation on aerosol deposition and respiratory epithelial permeability, we studied 26 normal nonsmokers, 12 smokers without airway obstruction, 12 nonsmokers with chronic obstructive pulmonary disease (COPD), and 11 smokers with COPD. We aerosolized 99mTc-labeled diethylene triamine pentaacetic acid to particles approximately 1 micron activity median aerodynamic diameter. Levels of radioactivity were plotted semilogarithmically against time to calculate clearance as percent per minute. The distribution of radioactivity was homogeneous in control subjects and in smokers, but patchy in both groups with COPD. No difference was found between clearances of the control group (1.18 +/- 0.31% min-1), and nonsmoker COPD group (1.37 +/- 0.82% min-1), whereas values in smokers without COPD (4.00 +/- 1.70% min-1) and smokers with COPD (3.62 +/- 2.88% min-1) were significantly greater than in both nonsmoking groups. We conclude that (1) small particles appear to deposit peripherally, even with severe COPD; (2) respiratory epithelial permeability is normal in nonsmokers with COPD; (3) smoking increases permeability by a mechanism unrelated to air-flow limitation.

  12. Source term experiments project (STEP): aerosol characterization system

    SciTech Connect

    Schlenger, B.J.; Dunn, P.F.

    1985-01-01

    A series of four experiments is being conducted at Argonne National Laboratory's TREAT Reactor. They have been designed to provide some of the necessary data regarding magnitude and release rates of fission products from degraded fuel pins, physical and chemical characteristics of released fission products, and aerosol formation and transport phenomena. These are in-pile experiments, whereby the test fuel is heated by neutron induced fission and subsequent clad oxidation in steam environments that simulate as closely as practical predicted reactor accident conditions. The test sequences cover a range of pressure and fuel heatup rate, and include the effect of Ag/In/Cd control rod material.

  13. Application of GOES-12 Aerosol Optical Depths and OMI Aerosol Indices to Evaluate NOAA/NESDIS Hazard Mapping System Smoke Analysis

    NASA Astrophysics Data System (ADS)

    Zeng, J.; Kondragunta, S.

    2006-05-01

    NOAA/NESDIS Hazard Mapping System (HMS) provides biomass burning fires and smoke analysis products to users. The smoke analysis is done by human analysts by inspecting visible imagery and fire locations. Analysts have difficulty in drawing plumes once the plumes are removed from the source (fires) and mixed with clouds and other types of aerosols. NOAA/NESDIS also provides GOES Aerosol Optical Depth (AOD) product to the users. The AOD product is derived from visible radiance measurements using a look-up table which is created assuming a continental aerosol model. In this study we examine the usefulness of Aura Ozone Monitoring Instrument (OMI) Aerosol Index (AI) in evaluating the analyst drawn smoke plumes and GOES AODs corresponding to smoke plumes. OMI AI in the near UV and visible bands is capable of distinguishing between absorbing aerosols and non-absorbing aerosols. We will present analysis of GOES AODs, OMI AI, and HMS smoke analysis product for several prescribed and natural fires observed during 2005. This analysis is expected to provide information on average percent area overlap between GOES AOD and HMS smoke plumes, OMI AI and HMS smoke plumes, and GOES AOD and OMI AI that will lead to an assessment of HMS smoke analysis.

  14. Clinical assessment of a commercial aerosol delivery system for ventilation scanning by comparison with KR-81m

    SciTech Connect

    Wollmer, P.; Eriksson, L.; Andersson, A.C.

    1984-01-01

    Radioactive aerosols offer a means for steady state ventilation scanning in multiple views. The clinical use of radioaerosol techniques has been hampered by the lack of delivery systems producing sufficiently small particles. If the aerosol contains large particles, heavy deposition occurs in major airways, especially in patients with airways disease. The authors have assessed a new, commercial aerosol delivery system (Syntevent) by comparison with Kr-81m ventilation scanning in 23 patients with airways obstruction. An indirect comparison was also made with a settling bad technique. Ventilation scans in four projections were obtained during continuous inhalation of Kr-81m. Subsequently, the patient inhaled an aerosol labelled with In-113m from the Syntevent system, and aerosol ventilation scans were obtained in the same projections. Spirometry was performed to establish the degree of airways obstruction. The aerosol delineated the ventilated regions of the lungs adequately in all the patients. Deposition of aerosol in larger airways was seen in a few patients only, and this did not impede the interpretation of the scintigram. A quantitative analysis of the penetration of the aerosol to the periphery of the lung failed to demonstrate any significant correlation between particle penetration and airways obstruction. Aerosol penetration was significantly greater (p<0.001) with the Syntevent system than with a settling bag technique.

  15. Aerosol sampling system for collection of Capstone depleted uranium particles in a high-energy environment.

    PubMed

    Holmes, Thomas D; Guilmette, Raymond A; Cheng, Yung Sung; Parkhurst, Mary Ann; Hoover, Mark D

    2009-03-01

    The Capstone Depleted Uranium (DU) Aerosol Study was undertaken to obtain aerosol samples resulting from a large-caliber DU penetrator striking an Abrams or Bradley test vehicle. The sampling strategy was designed to (1) optimize the performance of the samplers and maintain their integrity in the extreme environment created during perforation of an armored vehicle by a DU penetrator, (2) collect aerosols as a function of time post perforation, and (3) obtain size-classified samples for analysis of chemical composition, particle morphology, and solubility in lung fluid. This paper describes the experimental setup and sampling methodologies used to achieve these objectives. Custom-designed arrays of sampling heads were secured to the inside of the target in locations approximating the breathing zones of the crew locations in the test vehicles. Each array was designed to support nine filter cassettes and nine cascade impactors mounted with quick-disconnect fittings. Shielding and sampler placement strategies were used to minimize sampler loss caused by the penetrator impact and the resulting fragments of eroded penetrator and perforated armor. A cyclone train was used to collect larger quantities of DU aerosol for measurement of chemical composition and solubility. A moving filter sample was used to obtain semicontinuous samples for DU concentration determination. Control for the air samplers was provided by five remotely located valve control and pressure monitoring units located inside and around the test vehicle. These units were connected to a computer interface chassis and controlled using a customized LabVIEW engineering computer control program. The aerosol sampling arrays and control systems for the Capstone study provided the needed aerosol samples for physicochemical analysis, and the resultant data were used for risk assessment of exposure to DU aerosol. PMID:19204482

  16. Secondary Organic Aerosol Formation and Aging in a Flow Reactor in the Forested Southeast US during SOAS

    NASA Astrophysics Data System (ADS)

    Hu, W.; Palm, B. B.; Hacker, L.; Campuzano Jost, P.; Day, D. A.; Simoes de Sa, S.; Fry, J.; Ayres, B. R.; Draper, D. C.; Ortega, A. M.; Kiendler-Scharr, A.; Panujoka, A.; Virtanen, A.; Miettinen, P.; Krechmer, J.; Canagaratna, M. R.; Thompson, S.; Yatavelli, L. R.; Stark, H.; Worsnop, D. R.; Lechner, M.; Martin, S. T.; Farmer, D.; Brown, S. S.; Jimenez, J. L.

    2013-12-01

    A major field campaign (Southern Oxidant and Aerosol Study, SOAS) was conducted in summer 2013 in a forested area (Centreville Supersite) in the southeast U.S. To investigate secondary organic aerosol (SOA) formation from biogenic volatile organic compounds (BVOCs), 3 flow reactors (potential aerosol mass, PAM) were used to expose ambient air to oxidants and their output was analyzed by state-of-art gas and aerosol instruments including a High-Resolution Aerosol Mass Spectrometer (HR-AMS), a High-Resolution Proton-Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOFMS), and for the first time, two different High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometers (HRToF-CIMS), and an SMPS. Ambient air was exposed 24/7 to variable concentrations of each of the 3 main atmospheric oxidants (OH, O3 and NO3) to investigate SOA formation and aging. The OH exposure was estimated by 3 different methods (empirical parameterization, carbon monoxide consumption, and chemical box model). Effective OH exposures up to 7e12 molec cm-3 s were achieved, which is equivalent to over a month of aging in the atmosphere. High SOA formation of up to 12 μg m-3 above ambient concentrations of 5 μg m-3 was observed under intermediate OH exposures, while very high OH exposures led to destruction of ambient OA by ≈ 30%, indicating shifting contributions of functionalization vs. fragmentation, which is similar to previous results from urban and terpene-dominated environments. The highest SOA enhancements were 3-4 times higher than the ambient OA. More SOA is typically formed during nighttime when terpenes are higher and lower during daytime when isoprene is higher. SOA formation is also observed after exposure of ambient air to O3 or NO3, although the amount and oxidation was lower than for OH exposure. Formation of organic nitrates in the NO3 reaction will be discussed. High SOA formation (above 40 μg m-3) and a large number of CIMS ions, indicating many different

  17. A Study of the Flow Patterns of Expanding Impurity Aerosol Following a Disruption Event in a Fusion Reactor

    NASA Astrophysics Data System (ADS)

    Majumdar, Rudrodip

    The current study focuses on the adiabatic expansion of aerosol impurity in the post-disruption and thermal quench scenario inside the vacuum chamber of a fusion reactor. A pulsed electrothermal plasma (ET) capillary source has been used as a source term simulating the surface ablation of the divertor or other interior critical components of a tokamak fusion reactor under hard disruption-like conditions. The capillary source generates particulates from wall evaporation by depositing transient radiant high heat flux onto the inner liner of the capillary. The particulates form a plasma jet moving towards the capillary exit at high speed and high pressure. The first chapter discusses briefly the relevance of the study pertaining to the impurities in a fusion reactor based on the work available in the form of published literature. The second chapter discusses briefly the operating principle of a pulsed electrothermal plasma source (PEPS), the virtual integration of PEPS with 1-D electrothermal plasma flow solver ETFLOW and the use of capillary plasma sources in various industrial applications. The third chapter discusses about primitive computational work, backed by the data from actual electrothermal source experiments from the in-house facility "PIPE" (Plasma Interactions with Propellants Experiment), that shows the supersonic bulk flow patterns for the temperature, density, pressure, bulk velocity and the flow Mach number of the impurity particulates as they get ejected as a high-pressure, high-temperature and hyper-velocity jet from the simulated source term. It also shows the uniform steady-state subsonic expansion of bulk aerosol inside the expansion chamber. The fourth chapter discusses scaling laws in 1-D for the aforesaid bulk plasma parameters for ranges of axial length traversed by the flow, so that one can retrieve the flow parameters at some preferred locations. The fifth chapter discusses the effect of temperature and the non--linearity of the adiabatic

  18. A high flow turbine CPAP system.

    PubMed

    Moran, J L; Jackson, M P; Cameron, D M; Peisach, A R; Cunningham, D N; O'Fathartaigh, M S

    1988-01-01

    A continuous high flow CPAP system incorporating a turbine blower is described. The system achieves inspiratory flow rates of 150 l/min or more by means of reticulated gas flow and inspired oxygen fractions of 0.21-0.95. Positive airway pressure is provided by weighted disc valves and a modified aviation-type CPAP face mask provides electronic communication with the patient. The mobility of the system also enables its use as an intermittent physiotherapy aid. Work of breathing of the system, as assessed by total pressure fluctuations is at a minimum. PMID:3053845

  19. Assimilating aerosol observations with a "hybrid" variational-ensemble data assimilation system

    NASA Astrophysics Data System (ADS)

    Schwartz, Craig S.; Liu, Zhiquan; Lin, Hui-Chuan; Cetola, Jeffrey D.

    2014-04-01

    Total 550 nm aerosol optical depth, surface fine particulate matter (PM2.5), and meteorological observations were assimilated with continuously cycling three-dimensional variational (3DVAR), ensemble square root Kalman filter (EnSRF), and hybrid variational-ensemble data assimilation systems. The hybrid system's background error covariances (BECs) were a blend of those in 3DVAR and produced by the cycling EnSRF system, and the 3DVAR, EnSRF, and hybrid systems differed almost exclusively by their BECs. New analyses were produced every 6 h between 0000 UTC 1 June and 1800 UTC 14 July 2010 over a domain encompassing the contiguous United States (CONUS) and adjacent areas. Additionally, a control experiment that only assimilated meteorological observations was performed. Each 1800 UTC analysis initialized a 48 h Weather Research and Forecasting with Chemistry model forecast. These forecasts were evaluated with a focus on air quality prediction. The ensemble aerosol spread was generally insufficient, particularly over the western CONUS. However, despite the suboptimal ensemble spread, the hybrid system performed quite well and usually produced the best aerosol forecasts. Additionally, both the 3DVAR- and EnSRF-initialized forecasts typically outperformed the control. These results are encouraging and suggest the resiliency of the hybrid method. Improved aerosol ensembles should translate into even better future hybrid forecasts.

  20. Enhancement of Aerosol Cisplatin Chemotherapy with Gene Therapy Expressing ABC10 protein in Respiratory System

    PubMed Central

    Hohenforst-Schmidt, Wolfgang; Zarogoulidis, Paul; Linsmeier, Bernd; Kioumis, Ioannis; Li, Qiang; Huang, Haidong; Sachpatzidou, Despoina; Lampaki, Sofia; Organtzis, John; Domvri, Kalliopi; Sakkas, Leonidas; Zachariadis, George A.; Archontas, Konstantinos N.; Kallianos, Anastasios; Rapti, Aggeliki; Yarmus, Lonny; Zarogoulidis, Konstantinos; Brachmann, Johannes

    2014-01-01

    Inhaled therapy for lung cancer is a local form of treatment. Currently inhaled non-specific cytotoxic agents have been evaluated as a future treatment for local disease control and distant metastasis control. There are few information regarding the influence of local transporters and gene expression of the respiratory epithelium to the absorption of administered drugs. In the current work we used adenoviral-type 5(dE1/E3) (Cytomegalovirus promoter) with human ABCA10 transgene (Ad-h-ABCA10) purchased from Vector Labs® in order to investigate whether gene therapy can be used as a pre-treatment to enhance the efficiency of inhaled cisplatin. We included the following groups to our work: a) control, b) aerosol vector, c) aerosol vector plus cisplatin, d) aerosol cisplatin, e) intratumoral cisplatin administration, f) intratumoral vector plus cisplatin administration. The results indicate that the aerosol cisplatin group had a long term survival with the intratumoral cisplatin group following. The enhancement of the ABCA family locally to the respiratory system prior to the aerosol cisplatin administration can be used safely and efficiently. Future treatment design of local therapies should include the investigation of local transporters and genes. PMID:24723977

  1. Space Borne Cloud and Aerosol Measurements by the Geoscience Laser Altimeter System: Initial Results

    NASA Technical Reports Server (NTRS)

    Spinhirne, James D.; Palm, Steven P.; Hlavka, Dennis L.; Hart, William D.; Mahesh, Ashwin; Welton, Ellsworth J.

    2003-01-01

    In January 2003 the Geoscience Laser Altimeter System (GLAS) was successfully launched into orbit. Beginning in March 2003 GLAS will provide global coverage lidar measurement of the height distribution of clouds and aerosol in the atmosphere for up to five years. The characteristic and value of the unique data will be presented. The instrument is a basic backscatter lidar that operates at two wavelengths, 532 and 1064 nm. The mission data products for atmospheric observations include the calibrated, observed, attenuated backscatter cross section for cloud and aerosol; height detection for multiple cloud layers; planetary boundary layer height; cirrus and aerosol optical depth and the height distribution of aerosol and cloud scattering cross section profiles. The data is expected to significantly enhance knowledge in several areas of atmospheric science, in particular the distribution, transport and influence of atmospheric aerosol and thin clouds. Measurements of the coverage and height of polar and cirrus cloud should be significantly more accurate than previous global observations. In March and April 2003, airborne and ground based data verification experiments will be carried out. Initial results from the verification experiments and the first several months of operation will be presented.

  2. Real-time detection method and system for identifying individual aerosol particles

    DOEpatents

    Gard, Eric E.; Coffee, Keith R.; Frank, Matthias; Tobias, Herbert J.; Fergenson, David P.; Madden, Norm; Riot, Vincent J.; Steele, Paul T.; Woods, Bruce W.

    2007-08-21

    An improved method and system of identifying individual aerosol particles in real time. Sample aerosol particles are collimated, tracked, and screened to determine which ones qualify for mass spectrometric analysis based on predetermined qualification or selection criteria. Screening techniques include one or more of determining particle size, shape, symmetry, and fluorescence. Only qualifying particles passing all screening criteria are subject to desorption/ionization and single particle mass spectrometry to produce corresponding test spectra, which is used to determine the identities of each of the qualifying aerosol particles by comparing the test spectra against predetermined spectra for known particle types. In this manner, activation cycling of a particle ablation laser of a single particle mass spectrometer is reduced.

  3. Aerosol analysis and forecast in the European Centre for Medium-Range Weather Forecasts Integrated Forecast System: Forward modeling

    NASA Astrophysics Data System (ADS)

    Morcrette, J.-J.; Boucher, O.; Jones, L.; Salmond, D.; Bechtold, P.; Beljaars, A.; Benedetti, A.; Bonet, A.; Kaiser, J. W.; Razinger, M.; Schulz, M.; Serrar, S.; Simmons, A. J.; Sofiev, M.; Suttie, M.; Tompkins, A. M.; Untch, A.

    2009-03-01

    This paper presents the aerosol modeling now part of the ECMWF Integrated Forecasting System (IFS). It includes new prognostic variables for the mass of sea salt, dust, organic matter and black carbon, and sulphate aerosols, interactive with both the dynamics and the physics of the model. It details the various parameterizations used in the IFS to account for the presence of tropospheric aerosols. Details are given of the various formulations and data sets for the sources of the different aerosols and of the parameterizations describing their sinks. Comparisons of monthly mean and daily aerosol quantities like optical depths against satellite and surface observations are presented. The capability of the forecast model to simulate aerosol events is illustrated through comparisons of dust plume events. The ECMWF IFS provides a good description of the horizontal distribution and temporal variability of the main aerosol types. The forecast-only model described here generally gives the total aerosol optical depth within 0.12 of the relevant observations and can therefore provide the background trajectory information for the aerosol assimilation system described in part 2 of this paper.

  4. NEW VERSATILE AEROSOL GENERATION SYSTEM DEVELOPED FOR USE IN A LARGE WIND TUNNEL

    EPA Science Inventory

    A new aerosol generation system was developed to accommodate a variety of research activities performed within a large wind tunnel. Because many of the velocity measurements are taken in the wind tunnel with a laser Doppler anemometer (LDA), it is necessary to maintain an aero...

  5. Radial diffusion and penetration of gas molecules and aerosol particles through laminar flow reactors, denuders, and sampling tubes.

    PubMed

    Knopf, Daniel A; Pöschl, Ulrich; Shiraiwa, Manabu

    2015-04-01

    Flow reactors, denuders, and sampling tubes are essential tools for many applications in analytical and physical chemistry and engineering. We derive a new method for determining radial diffusion effects and the penetration or transmission of gas molecules and aerosol particles through cylindrical tubes under laminar flow conditions using explicit analytical equations. In contrast to the traditional Brown method [Brown, R. L. J. Res. Natl. Bur. Stand. (U. S.) 1978, 83, 1-8] and CKD method (Cooney, D. O.; Kim, S. S.; Davis, E. J. Chem. Eng. Sci. 1974, 29, 1731-1738), the new approximation developed in this study (known as the KPS method) does not require interpolation or numerical techniques. The KPS method agrees well with the CKD method under all experimental conditions and also with the Brown method at low Sherwood numbers. At high Sherwood numbers corresponding to high uptake on the wall, flow entry effects become relevant and are considered in the KPS and CKD methods but not in the Brown method. The practical applicability of the KPS method is demonstrated by analysis of measurement data from experimental studies of rapid OH, intermediate NO3, and slow O3 uptake on various organic substrates. The KPS method also allows determination of the penetration of aerosol particles through a tube, using a single equation to cover both the limiting cases of high and low deposition described by Gormley and Kennedy (Proc. R. Ir. Acad., Sect. A. 1949, 52A, 163-169). We demonstrate that the treatment of gas and particle diffusion converges in the KPS method, thus facilitating prediction of diffusional loss and penetration of gases and particles, analysis of chemical kinetics data, and design of fluid reactors, denuders, and sampling lines. PMID:25744622

  6. Acoustic Flow Monitor System - User Manual

    USGS Publications Warehouse

    LaHusen, Richard

    2005-01-01

    INTRODUCTION The Acoustic Flow Monitor (AFM) is a portable system that was designed by the U.S. Geological Survey Cascades Volcano Observatory to detect and monitor debris flows associated with volcanoes. It has been successfully used internationally as part of real-time warning systems in valleys threatened by such flows (Brantley, 1990; Marcial and others, 1996; Lavigne and others, 2000). The AFM system has also been proven to be an effective tool for monitoring some non-volcanic debris flows. This manual is intended to serve as a basic guide for the installation, testing, and maintenance of AFM systems. An overview of how the system works, as well as instructions for installation and guidelines for testing, is included. Interpretation of data is not covered in this manual; rather, the user should refer to the references provided for published examples of AFM data.

  7. LADEE Propulsion System Cold Flow Test

    NASA Technical Reports Server (NTRS)

    Williams, Jonathan Hunter; Chapman, Jack M.; Trinh, Hau, P.; Bell, James H.

    2013-01-01

    Lunar Atmosphere and Dust Environment Explorer (LADEE) is a NASA mission that will orbit the Moon. Its main objective is to characterize the atmosphere and lunar dust environment. The spacecraft development is being led by NASA Ames Research Center and scheduled for launch in 2013. The LADEE spacecraft will be operated with a bi-propellant hypergolic propulsion system using MMH and NTO as the fuel and oxidizer, respectively. The propulsion system utilizes flight-proven hardware on major components. The propulsion layout is composed of one 100-lbf main thruster and four 5-lbf RCS thrusters. The propellants are stored in four tanks (two parallel-connected tanks per propellant component). The propellants will be pressurized by regulated helium. A simulated propulsion system has been built for conducting cold flow test series to characterize the transient fluid flow of the propulsion system feed lines and to verify the critical operation modes, such as system priming, waterhammer, and crucial mission duty cycles. Propellant drainage differential between propellant tanks will also be assessed. Since the oxidizer feed line system has a higher flow demand than the fuel system does, the cold flow test focuses on the oxidizer system. The objective of the cold flow test is to simulate the LADEE propulsion fluid flow operation through water cold flow test and to obtain data for anchoring analytical models. The models will be used to predict the transient and steady state flow behaviors in the actual flight operations. The test activities, including the simulated propulsion test article, cold flow test, and analytical modeling, are being performed at NASA Marshall Space Flight Center. At the time of the abstract submission, the test article checkout is being performed. The test series will be completed by November, 2012

  8. Relative influence of meteorological conditions and aerosols on the lifetime of mesoscale convective systems.

    PubMed

    Chakraborty, Sudip; Fu, Rong; Massie, Steven T; Stephens, Graeme

    2016-07-01

    Using collocated measurements from geostationary and polar-orbital satellites over tropical continents, we provide a large-scale statistical assessment of the relative influence of aerosols and meteorological conditions on the lifetime of mesoscale convective systems (MCSs). Our results show that MCSs' lifetime increases by 3-24 h when vertical wind shear (VWS) and convective available potential energy (CAPE) are moderate to high and ambient aerosol optical depth (AOD) increases by 1 SD (1σ). However, this influence is not as strong as that of CAPE, relative humidity, and VWS, which increase MCSs' lifetime by 3-30 h, 3-27 h, and 3-30 h per 1σ of these variables and explain up to 36%, 45%, and 34%, respectively, of the variance of the MCSs' lifetime. AOD explains up to 24% of the total variance of MCSs' lifetime during the decay phase. This result is physically consistent with that of the variation of the MCSs' ice water content (IWC) with aerosols, which accounts for 35% and 27% of the total variance of the IWC in convective cores and anvil, respectively, during the decay phase. The effect of aerosols on MCSs' lifetime varies between different continents. AOD appears to explain up to 20-22% of the total variance of MCSs' lifetime over equatorial South America compared with 8% over equatorial Africa. Aerosols over the Indian Ocean can explain 20% of total variance of MCSs' lifetime over South Asia because such MCSs form and develop over the ocean. These regional differences of aerosol impacts may be linked to different meteorological conditions. PMID:27313203

  9. Relative influence of meteorological conditions and aerosols on the lifetime of mesoscale convective systems

    NASA Astrophysics Data System (ADS)

    Chakraborty, Sudip; Fu, Rong; Massie, Steven T.; Stephens, Graeme

    2016-07-01

    Using collocated measurements from geostationary and polar-orbital satellites over tropical continents, we provide a large-scale statistical assessment of the relative influence of aerosols and meteorological conditions on the lifetime of mesoscale convective systems (MCSs). Our results show that MCSs’ lifetime increases by 3–24 h when vertical wind shear (VWS) and convective available potential energy (CAPE) are moderate to high and ambient aerosol optical depth (AOD) increases by 1 SD (1σ). However, this influence is not as strong as that of CAPE, relative humidity, and VWS, which increase MCSs’ lifetime by 3–30 h, 3–27 h, and 3–30 h per 1σ of these variables and explain up to 36%, 45%, and 34%, respectively, of the variance of the MCSs’ lifetime. AOD explains up to 24% of the total variance of MCSs’ lifetime during the decay phase. This result is physically consistent with that of the variation of the MCSs’ ice water content (IWC) with aerosols, which accounts for 35% and 27% of the total variance of the IWC in convective cores and anvil, respectively, during the decay phase. The effect of aerosols on MCSs’ lifetime varies between different continents. AOD appears to explain up to 20–22% of the total variance of MCSs’ lifetime over equatorial South America compared with 8% over equatorial Africa. Aerosols over the Indian Ocean can explain 20% of total variance of MCSs’ lifetime over South Asia because such MCSs form and develop over the ocean. These regional differences of aerosol impacts may be linked to different meteorological conditions.

  10. Improving aerosol interaction with clouds and precipitation in a regional chemical weather modeling system

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Zhang, X.; Gong, S.

    2015-12-01

    A comprehensive aerosol-cloud-precipitation interaction (ACI) scheme has been developed under CMA chemical weather modeling system GRAPES/CUACE. Calculated by a sectional aerosol activation scheme based on the information of size and mass from CUACE and the thermal-dynamic and humid states from the weather model GRAPES at each time step, the cloud condensation nuclei (CCN) is fed online interactively into a two-moment cloud scheme (WDM6) and a convective parameterization to drive the cloud physics and precipitation formation processes. The modeling system has been applied to study the ACI for January 2013 when several persistent haze-fog events and eight precipitation events occurred. The results show that interactive aerosols with the WDM6 in GRAPES/CUACE obviously increase the total cloud water, liquid water content and cloud droplet number concentrations while decrease the mean diameter of cloud droplets with varying magnitudes of the changes in each case and region. These interactive micro-physical properties of clouds improve the calculation of their collection growth rates in some regions and hence the precipitation rate and distributions in the model, showing 24% to 48% enhancements of TS scoring for 6-h precipitation in almost all regions. The interactive aerosols with the WDM6 also reduce the regional mean bias of temperature by 3 °C during certain precipitation events, but the monthly means bias is only reduced by about 0.3°C.

  11. Improving aerosol interaction with clouds and precipitation in a regional chemical weather modeling system

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Zhang, X.; Gong, S.; Wang, Y.; Xue, M.

    2015-06-01

    A comprehensive aerosol-cloud-precipitation interaction (ACI) scheme has been developed under CMA chemical weather modeling system GRAPES/CUACE. Calculated by a sectional aerosol activation scheme based on the information of size and mass from CUACE and the thermal-dynamic and humid states from the weather model GRAPES at each time step, the cloud condensation nuclei (CCN) is fed online interactively into a two-moment cloud scheme (WDM6) and a convective parameterization to drive the cloud physics and precipitation formation processes. The modeling system has been applied to study the ACI for January 2013 when several persistent haze-fog events and eight precipitation events occurred. The results show that interactive aerosols with the WDM6 in GRAPES/CUACE obviously increase the total cloud water, liquid water content and cloud droplet number concentrations while decrease the mean diameter of cloud droplets with varying magnitudes of the changes in each case and region. These interactive micro-physical properties of clouds improve the calculation of their collection growth rates in some regions and hence the precipitation rate and distributions in the model, showing 24 to 48% enhancements of TS scoring for 6 h precipitation in almost all regions. The interactive aerosols with the WDM6 also reduce the regional mean bias of temperature by 3 °C during certain precipitation events, but the monthly means bias is only reduced by about 0.3 °C.

  12. Non-aerosol detection of explosives with a continuous flow immunosensor.

    PubMed

    Shriver-Lake, Lisa C; Charles, Paul T; Kusterbeck, Anne W

    2003-10-01

    Contamination of groundwater, soil, and the marine environment by explosives is a global issue. Identification, characterization and remediation are all required for a site recognized as contaminated with 2,4,6-trinitrotoluene (TNT) or hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). For each step, a method to accurately measure the contaminant level is needed. This paper reviews some of the current methods with emphasis on a single biosensor developed in our laboratory. Current regulatory methods require samples to be sent off-site to a certified laboratory resulting in time delays up to a month. A continuous flow biosensor for detection of explosives has been developed and tested for the rapid field screening of environmental samples. The detection system is based on a displacement immunoassay in which monoclonal antibodies to (TNT) and RDX are immobilized on solid substrates, allowed to bind fluorescently labeled antigens, and then exposed to explosives in aqueous samples. Explosive compounds present in the sample displace proportional amounts of the fluorescent label, which can then be measured to determine the original TNT or RDX concentration. The system can accurately detect ppb to ppt levels of explosives in groundwater or seawater samples and in extracts of contaminated soil. The biosensor has applications in environmental monitoring at remediation sites or in the location of underwater unexploded ordnance. PMID:12920500

  13. Aerosol seeding systems for the NSWC wind tunnels

    NASA Technical Reports Server (NTRS)

    Yanta, W. J.; Smith, T. S.; Collier, A. S.

    1985-01-01

    Four types of laskin nozzles which are used to generate the primary aerosol mist are illustrated. This mist may be used directly as laser doppler velocimeters (LDV) particles. However, in general, a wide range of particle size exists at this stage and requires the use of some type of mono-dispersion refinement technique. These nozzles rely on the shearing action of high speed air near a column of seeding liquid. Typically, olive oil or dioctyl phthalate (DOP) is used, but within the past year solid polystyrene particles in an alcohol suspension have been used with great success. Air, at a typical pressure of five psig, is supplied to the top of the nozzle which is merely a hollow tube. This air issues radially from one or more small jets located near the collar close to the bottom of the tube. When the collar is submerged in the seeding liquid, the hollow columns located in the collar become filled with liquid. The air from the jet shears the liquid into the fine mist.

  14. Flow Battery System Design for Manufacturability.

    SciTech Connect

    Montoya, Tracy Louise; Meacham, Paul Gregory; Perry, David; Broyles, Robin S.; Hickey, Steven; Hernandez, Jacquelynne

    2014-10-01

    Flow battery energy storage systems can support renewable energy generation and increase energy efficiency. But, presently, the costs of flow battery energy storage systems can be a significant barrier for large-scale market penetration. For cost- effective systems to be produced, it is critical to optimize the selection of materials and components simultaneously with the adherence to requirements and manufacturing processes to allow these batteries and their manufacturers to succeed in the market by reducing costs to consumers. This report analyzes performance, safety, and testing requirements derived from applicable regulations as well as commercial and military standards that would apply to a flow battery energy storage system. System components of a zinc-bromine flow battery energy storage system, including the batteries, inverters, and control and monitoring system, are discussed relative to manufacturing. The issues addressed include costs and component availability and lead times. A service and support model including setup, maintenance and transportation is outlined, along with a description of the safety-related features of the example flow battery energy storage system to promote regulatory and environmental, safety, and health compliance in anticipation of scale manufacturing.

  15. Engineering Upgrades to the Radionuclide Aerosol Sampler/Analyzer for the CTBT International Monitoring System

    SciTech Connect

    Forrester, Joel B.; Carty, Fitz; Comes, Laura; Hayes, James C.; Miley, Harry S.; Morris, Scott J.; Ripplinger, Mike D.; Slaugh, Ryan W.; Van Davelaar, Peter

    2013-05-13

    The Radionuclide Aerosol Sampler/Analyzer (RASA) is an automated aerosol collection and analysis system designed by Pacific Northwest National Laboratory in the 1990’s and is deployed in several locations around the world as part of the International Monitoring System (IMS) required under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The utility of such an automated system is the reduction of human intervention and the production of perfectly uniform results. However, maintainability and down time issues threaten this utility, even for systems with over 90% data availability. Engineering upgrades to the RASA are currently being pursued to address these issues, as well as Fukushima lessons learned. Current work includes a new automation control unit, and other potential improvements such as alternative detector cooling and sampling options are under review. This paper presents the current state of upgrades and improvements under investigation

  16. Neural network system for traffic flow management

    NASA Astrophysics Data System (ADS)

    Gilmore, John F.; Elibiary, Khalid J.; Petersson, L. E. Rickard

    1992-09-01

    Atlanta will be the home of several special events during the next five years ranging from the 1996 Olympics to the 1994 Super Bowl. When combined with the existing special events (Braves, Falcons, and Hawks games, concerts, festivals, etc.), the need to effectively manage traffic flow from surface streets to interstate highways is apparent. This paper describes a system for traffic event response and management for intelligent navigation utilizing signals (TERMINUS) developed at Georgia Tech for adaptively managing special event traffic flows in the Atlanta, Georgia area. TERMINUS (the original name given Atlanta, Georgia based upon its role as a rail line terminating center) is an intelligent surface street signal control system designed to manage traffic flow in Metro Atlanta. The system consists of three components. The first is a traffic simulation of the downtown Atlanta area around Fulton County Stadium that models the flow of traffic when a stadium event lets out. Parameters for the surrounding area include modeling for events during various times of day (such as rush hour). The second component is a computer graphics interface with the simulation that shows the traffic flows achieved based upon intelligent control system execution. The final component is the intelligent control system that manages surface street light signals based upon feedback from control sensors that dynamically adapt the intelligent controller's decision making process. The intelligent controller is a neural network model that allows TERMINUS to control the configuration of surface street signals to optimize the flow of traffic away from special events.

  17. Capstone Depleted Uranium Aerosols: Generation and Characterization

    SciTech Connect

    Parkhurst, MaryAnn; Szrom, Fran; Guilmette, Ray; Holmes, Tom; Cheng, Yung-Sung; Kenoyer, Judson L.; Collins, John W.; Sanderson, T. Ellory; Fliszar, Richard W.; Gold, Kenneth; Beckman, John C.; Long, Julie

    2004-10-19

    In a study designed to provide an improved scientific basis for assessing possible health effects from inhaling depleted uranium (DU) aerosols, a series of DU penetrators was fired at an Abrams tank and a Bradley fighting vehicle. A robust sampling system was designed to collect aerosols in this difficult environment and continuously monitor the sampler flow rates. Aerosols collected were analyzed for uranium concentration and particle size distribution as a function of time. They were also analyzed for uranium oxide phases, particle morphology, and dissolution in vitro. The resulting data provide input useful in human health risk assessments.

  18. The System of the Calibration for Visibility Measurement Instrument Under the Atmospheric Aerosol Simulation Environment

    NASA Astrophysics Data System (ADS)

    Shu, Zhifeng; Yang, ShaoChen; Xu, Wenjing

    2016-06-01

    Visibility is one of the most important parameters for meteorological observation and numerical weather prediction (NWP).It is also an important factor in everyday life, mainly for surface and air traffic especially in the Aeronautical Meteorology. The visibility decides the taking off and landing of aircraft. If the airport visibility is lower than requirement for aircraft taking off stipulated by International Civil Aviation Administration, then the aircraft must be parked at the airport. So the accurate measurement of visibility is very important. Nowadays, many devices can be measured the visibility or meteorological optical range (MOR) such as Scatterometers, Transmissometers and visibility lidar. But there is not effective way to verify the accuracy of these devices expect the artificial visual method. We have developed a visibility testing system that can be calibration and verification these devices. The system consists of laser transmitter, optical chopper, phase-locking amplifier, the moving optic receiving system, signal detection and data acquisition system, atmospheric aerosol simulation chamber. All of them were placed in the atmosphere aerosol simulation chamber with uniform aerosol concentration. The Continuous wave laser, wavelength 550nm, has been transmitted into the collimation system then the laser beam expanded into 40mm diameter for compressing the laser divergence angle before modulated by optical chopper. The expanding beam transmitting in the atmosphere aerosol cabin received by the optic receiving system moving in the 50m length precision guide with 100mm optical aperture. The data of laser signal has been acquired by phase-locking amplifier every 5 meter range. So the 10 data points can be detected in the 50 meters guide once. The slope of the fitting curve can be obtained by linear fitting these data using the least square method. The laser extinction coefficient was calculated from the slope using the Koschmieder formula, then it been

  19. Secondary Organic Aerosol Formation and Aging in a Flow Reactor in the Forested Southeast US during SOAS

    NASA Astrophysics Data System (ADS)

    Hu, W.; Palm, B. B.; Hacker, L.; Campuzano Jost, P.; Day, D. A.; de Sá, S. S.; Ayres, B. R.; Draper, D.; Fry, J.; Ortega, A. M.; Kiendler-Scharr, A.; Pajunoja, A.; Virtanen, A.; Krechmer, J.; Canagaratna, M. R.; Thompson, S.; Yatavelli, R. L. N.; Stark, H.; Worsnop, D. R.; Martin, S. T.; Farmer, D.; Brown, S. S.; Jimenez, J. L.

    2015-12-01

    A major field campaign (Southern Oxidant and Aerosol Study, SOAS) was conducted in summer 2013 in a forested area in Centreville Supersite, AL (SEARCH network) in the southeast U.S. To investigate secondary organic aerosol (SOA) formation from biogenic volatile organic compounds (BVOCs), 3 oxidation flow reactors (OFR) were used to expose ambient air to oxidants and their output was analyzed by state-of-the-art gas and aerosol instruments including a High-Resolution Aerosol Mass Spectrometer (HR-AMS), a HR Proton-Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOFMS), and Two HR-TOF Chemical Ionization Mass Spectrometers (HRToF-CIMS). Ambient air was exposed 24/7 to variable concentrations of each of the 3 main atmospheric oxidants (OH, NO3 radicals and O3) to investigate the oxidation of BVOCs (including isoprene derived epoxydiols, IEPOX) and SOA formation and aging. Effective OH exposures up to 1×1013 molec cm-3 s were achieved, equivalent to over a month of aging in the atmosphere. Multiple oxidation products from isoprene and monoterpenes including small gas-phase acids were observed in OH OFR. High SOA formation of up to 12 μg m-3 above ambient concentrations of 5 μg m-3 was observed under intermediate OH exposures, while very high OH exposures led to destruction of ~30% of ambient OA, indicating shifting contributions of functionalization vs. fragmentation, consistent with results from urban and terpene-dominated environments. The highest SOA enhancements were 3-4 times higher than ambient OA. More SOA is typically formed during nighttime when terpenes are higher and photochemistry is absent, and less during daytime when isoprene is higher, although the IEPOX pathway is suppressed in the OFR. SOA is also observed after exposure of ambient air to O3 or NO3, although the amounts and oxidation levels were lower than for OH. Formation of organic nitrates in the NO3 reaction will also be discussed.A major field campaign (Southern Oxidant and Aerosol

  20. The effect of water on gas-particle partitioning of secondary organic aerosol. Part I: α-pinene/ozone system

    NASA Astrophysics Data System (ADS)

    Cocker, David R., III; Clegg, Simon L.; Flagan, Richard C.; Seinfeld, John H.

    The effect of relative humidity (RH) on aerosol formation by the semi-volatile oxidation products of the α-pinene/O 3 system has been comprehensively studied. Experiments were performed in the presence of ammonium sulfate (aqueous, dry), ammonium bisulfate seed (aqueous, dry), and aqueous calcium chloride seed aerosols to ascertain their effect on the partitioning of the oxidation products. The yield of organic aerosol varies little with RH, and is not affected by the presence of dry inorganic salt aerosols. Aqueous salt aerosols reduce the yield of organic aerosol compared to that under seed-free or dry seed conditions. The degree of reduction is electrolyte dependent, with aqueous ammonium sulfate leading to the largest reduction and aqueous calcium chloride the smallest. Hygroscopic growth of the organic aerosol from <2% to 85% RH was also monitored, and could be satisfactorily represented as the sum of the individual contributions of the organic and inorganic fractions. The implications of the growth factor measurements for concentration/activity relationships of the condensed phase organic material (assuming a liquid solution) was explored. The formation of the organic aerosol was investigated using a simple two component model, and also one including the 12 product compounds identified in a previous study. The experimental results for <2% and 50% RH (without salt seed aerosols) could be satisfactorily predicted. However, the aqueous salt seed aerosols are predicted to increase the overall yield due to the dissolution of the organic compounds into the water associated with the seed aerosol—the opposite effect to that observed. The implications of two distinct phases existing the aerosol phase were investigated.

  1. New Lidar Capabilities in Space: An Overview of the Cloud-Aerosol Transport System (CATS)

    NASA Astrophysics Data System (ADS)

    McGill, M. J.; Yorks, J. E.; Hlavka, D. L.; Selmer, P. A.; Hart, W. D.; Palm, S. P.; Nowottnick, E. P.; Vaughan, M.; Rodier, S. D.; Colarco, P. R.; da Silva, A.; Buchard, V.

    2014-12-01

    The Cloud-Aerosol Transport System (CATS), built at NASA Goddard Space Flight Center as a payload for the International Space Station (ISS), is set to launch in the late 2014. CATS is an elastic backscatter lidar operating in one of three science modes with three wavelengths (1064, 532, 355 nm) and HSRL capability at 532 nm. Depolarization measurements will be made at the 532 and 1064 nm wavelengths. The CATS science modes are described in Figure 1. The ISS orbit is a 51 degree inclination orbit at an altitude of about 405 km. This orbit provides more comprehensive coverage of the tropics and mid-latitudes than sun-synchronous orbiting sensors, with nearly a three day repeat cycle. Thus, science applications of CATS include cloud and aerosol climate studies, air quality monitoring, and smoke/volcanic plume tracking. Current uncertainties in cloud and aerosol properties limit our ability to accurately model the Earth's climate system and predict climate change. These limitations are due primarily to difficulties in adequately measuring aerosols and clouds on a global scale. A primary science objectives of CATS is to provide global aerosol and cloud vertical profile data in near real time to for assimilation in aerosol transport models such as the NASA GEOS-5 model. Furthermore, the vertical profiles of cloud and aerosol properties provided by CATS will complement current and future passive satellite sensors. Another important science objective of CATS is to advance technology in support of future mission development. CATS will employ 355 nm and HSRL capabilities, as well as depolarization at multiple wavelengths. These expanded measurement capabilities will provide the science community with new and improved global data products that have yet to be retrieved from space-based lidar. In preparation for launch, simulations of the CATS lidar signal are produced using GEOS5 model data to develop and test future data products. An example of the simulated CATS attenuated

  2. Ultrasonic flow imaging system: A feasibility study

    SciTech Connect

    Sheen, S.H.; Lawrence, W.P.; Chien, H.T.; Raptis, A.C.

    1991-09-01

    This report examines the feasibility and potential problems in developing a real-time ultrasonic flow imaging instrument for on-line monitoring of mixed-phased flows such as coal slurries. State-of-the-art ultrasonic imaging techniques are assessed for this application. Reflection and diffraction tomographies are proposed for further development, including image-reconstruction algorithms and parallel processing systems. A conventional ultrasonic C-scan technique is used to demonstrate the feasibility of imaging the particle motion in a solid/water flow. 13 refs., 11 figs.

  3. Power flow for spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Halpin, S. M.; Grigsby, L. L.; Sheble, G. B.; Nelms, R. M.

    1989-01-01

    A method for constructing the generalized system-level admittance matrix for use with a Newton-Raphson power flow is presented. The network modeling technique presented does not use the standard pi-equivalent models, which assume a lossless return path, for the transmission line and transformer. If the return path cannot be assumed lossless, then the standard algorithms for constructing the system admittance matrix cannot be used. The method presented here uses concepts from linear graph theory to combine network modules to form the system-level admittance matrix. The modeling technique is presented, and the resulting matrix is used with a standard Newton-Raphson power flow to calculate all system voltages and current (power) flows.

  4. Investigation of propellant flow control system

    NASA Technical Reports Server (NTRS)

    Liebman, A. A.

    1973-01-01

    Mechanical, electromechanical, and fluidic concepts were studied as propellant flow control system for oxygen/hydrogen attitude control thrusters. A mechanical flow controller was designed, fabricated, and tested with hydrogen, oxygen, and nitrogen over a range of inlet pressures and temperatures. Results of these tests are presented along with a discussion of a flight-weight design. Also presented are recommendations for further design and development. A detailed coverage of the fluidics investigation is included.

  5. Implementation of a new aerosol HAM model within the Weather Research and Forecasting (WRF) modeling system

    NASA Astrophysics Data System (ADS)

    Mashayekhi, R.; Irannejad, P.; Feichter, J.; Bidokhti, A. A.

    2009-07-01

    A new coupled system of aerosol HAM model and the Weather, Research and Forecasting (WRF) model is presented in this paper. Unlike the current aerosol schemes used in WRF model, the HAM is using a "pseudomodal" approach for the representation of the particle size distribution. The aerosol components considered are sulfate, black carbon, particulate organic matter, sea salt and mineral dust. The preliminary model results are presented for two different 6-day simulation periods from 22 to 28 February 2006 as a winter period and 6 to 12 May 2006 as a mild period. The mean shortwave radiation and thermal forcing were calculated from the model simulations with and without aerosols feedback for two simulation periods. A negative radiative forcing and cooling of the atmosphere were found mainly over the regions of high emission of mineral dust. The absorption of shortwave radiation by black carbon caused warming effects in some regions with positive radiative forcing. The simulated daily mean sulfate mass concentration showed a rather good agreement with the measurements in the European EMEP network. The diurnal variation of the simulated hourly PM10 mass concentration at Tehran was also qualitatively close to the observations in both simulation periods. The model captured diurnal cycle and the magnitude of the observed PM10 concentration during most of the simulation periods. The differences between the observed and simulated PM10 concentration resulted mostly from limitation of the model in simulating the clouds and precipitation, transport errors and uncertainties in the particulate emission rates. The inclusion of aerosols feedback in shortwave radiation scheme improved the simulated daily mean shortwave radiation fluxes in Tehran for both simulation periods.

  6. Potential Aerosol Mass (PAM) flow reactor measurements of SOA formation in a Ponderosa Pine forest in the southern Rocky Mountains during BEACHON-RoMBAS

    NASA Astrophysics Data System (ADS)

    Palm, B. B.; Ortega, A. M.; Campuzano Jost, P.; Day, D. A.; Kaser, L.; Karl, T.; Jud, W.; Hansel, A.; Fry, J.; Brown, S. S.; Zarzana, K. J.; Dube, W. P.; Wagner, N.; Draper, D.; Brune, W. H.; Jimenez, J. L.

    2012-12-01

    A Potential Aerosol Mass (PAM) photooxidation flow reactor was used in combination with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer to characterize biogenic secondary organic aerosol (SOA) formation in a terpene-dominated forest during the July-August 2011 Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen - Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS) field campaign at the U.S. Forest Service Manitou Forest Observatory, Colorado, as well as in corresponding laboratory experiments. In the PAM reactor, a chosen oxidant (OH, O3, or NO3) was generated and controlled over a range of values up to 10,000 times ambient levels. High oxidant concentrations accelerated the gas-phase, heterogeneous, and possibly aqueous oxidative aging of volatile organic compounds (VOCs), inorganic gases, and existing aerosol, which led to repartitioning into the aerosol phase. PAM oxidative processing represented from a few hours up to ~20 days of equivalent atmospheric aging during the ~3 minute reactor residence time. During BEACHON-RoMBAS, PAM photooxidation enhanced SOA at intermediate OH exposure (1-10 equivalent days) but resulted in net loss of OA at long OH exposure (10-20 equivalent days), demonstrating the competing effects of functionalization vs. fragmentation (and possibly photolysis) as aging increased. PAM oxidation also resulted in f44 vs. f43 and Van Krevelen diagram (H/C vs. O/C) slopes similar to ambient oxidation, suggesting the PAM reactor employs oxidation pathways similar to ambient air. Single precursor aerosol yields were measured using the PAM reactor in the laboratory as a function of organic aerosol concentration and reacted hydrocarbon amounts. When applying the laboratory PAM yields with complete consumption of the most abundant VOCs measured at the forest site (monoterpenes, sesquiterpenes, MBO, and toluene), a simple model underpredicted the amount of SOA formed in the PAM reactor in the

  7. Effects of explosively venting aerosol-sized particles through earth-containment systems on the cloud-stabilization height

    SciTech Connect

    Dyckes, G.W.

    1980-07-01

    A method of approximating the cloud stabilization height for aerosol-sized particles vented explosively through earth containment systems is presented. The calculated values for stabilization heights are in fair agreement with those obtained experimentally.

  8. DEVELOPMENT AND APPLICATION OF A NEW AIR POLLUTION MODELING SYSTEM--II. AEROSOL MODULE STRUCTURE AND DESIGN (R823186)

    EPA Science Inventory

    The methods used for simulating aerosol physical and chemical processes in a new air pollution modeling system are discussed and analyzed. Such processes include emissions, nucleation, coagulation, reversible chemistry, condensation, dissolution, evaporation, irreversible chem...

  9. From Traffic Flow to Economic System

    NASA Astrophysics Data System (ADS)

    Bando, M.

    The optimal velocity model which is applied to traffic flow phenomena explains a spontaneous formation of traffic congestion. We discuss why the model works well in describing both free-flow and congested flow states in a unified way. The essential ingredient is that our model takes account of a sort of time delay in reacting to a given stimulus. This causes instability of many-body system, and yields a kind of phase transition above a certain critical density. Especially there appears a limit cycle on the phase space along which individual vehicle moves, and they show cyclic behavior. Once that we recognize the mechanism the same idea can be applied to a variety of phenomena which show cyclic behavior observed in many-body systems. As an example of such applications, we investigate business cycles commonly observed in economic system. We further discuss a possible origin of a kind of cyclic behavior observed in climate change.

  10. Evolution of microbial aerosol behaviour in heating, ventilating and air-conditioning systems--quantification of Staphylococcus epidermidis and Penicillium oxalicum viability.

    PubMed

    Forthomme, A; Andrès, Y; Joubert, A; Simon, X; Duquenne, P; Bemer, D; Le Coq, L

    2012-01-01

    The aim of this study was to develop an experimental set-up and a methodology to uniformly contaminate several filter samples with high concentrations of cultivable bacteria and fungi. An experimental set-up allows contaminating simultaneously up to four filters for range of velocities representative of heating, ventilating and air-conditioning systems. The test aerosol was composed of a microbial consortium of one bacterium (Staphylococcus epidermidis) and one fungus (Penicillium oxalicum) and aerosol generation was performed in wet conditions. Firstly, the experimental set-up was validated in regards to homogeneity of the air flows. The bioaerosol was also characterized in terms of the number and particle size distribution using two particle counters: optical particle counter Grimm 1.109 (optical diameters) and TSI APS 3321 (aerodynamic diameters). Moreover, stabilities of the number of particles generated were measured. Finally, concentrations of cultivable microorganisms were measured with BioSamplers SKC downstream of the four filters. PMID:23393961

  11. Evolution of microbial aerosol behaviour in heating, ventilating and air-conditioning systems--quantification of Staphylococcus epidermidis and Penicillium oxalicum viability.

    PubMed

    Forthomme, A; Andrès, Y; Joubert, A; Simon, X; Duquenne, P; Bemer, D; Le Coq, L

    2013-01-01

    The aim of this study was to develop an experimental set-up and a methodology to uniformly contaminate several filter samples with high concentrations of cultivable bacteria and fungi. An experimental set-up allows contaminating simultaneously up to four filters for range of velocities representative of heating, ventilating and air-conditioning systems. The test aerosol was composed of a microbial consortium of one bacterium (Staphylococcus epidermidis) and one fungus (Penicillium oxalicum) and aerosol generation was performed in wet conditions. Firstly, the experimental set-up was validated in regards to homogeneity of the air flows. The bioaerosol was also characterized in terms of number and particle size distribution using two particle counters: optical particle counter Grimm 1.109 (optical diameters) and TSI APS 3321 (aerodynamic diameters). Moreover, stabilities of the number of particles generated were measured. Finally, concentrations of cultivable microorganisms were measured with BioSamplers (SKC) downstream of the four filters. PMID:23837350

  12. Redox flow cell energy storage systems

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.

    1979-01-01

    The redox flow cell energy storage system being developed by NASA for use in remote power systems and distributed storage installations for electric utilities is presented. The system under consideration is an electrochemical storage device which utilizes the oxidation and reduction of two fully soluble redox couples (acidified chloride solutions of chromium and iron) as active electrode materials separated by a highly selective ion exchange membrane. The reactants are contained in large storage tanks and pumped through a stack of redox flow cells where the electrochemical reactions take place at porous carbon felt electrodes. Redox equipment has allowed the incorporation of state of charge readout, stack voltage control and system capacity maintenance (rebalance) devices to regulate cells in a stack jointly. A 200 W, 12 V system with a capacity of about 400 Wh has been constructed, and a 2 kW, 10kWh system is planned.

  13. Internal-flow systems for aircraft

    NASA Technical Reports Server (NTRS)

    Rogallo, F M

    1940-01-01

    An investigation has been made to determine efficient arrangements for an internal-flow system of an aircraft when such a system operates by itself or in combination with other flow systems. The investigation included a theoretical treatment of a problem and tests in the NACA 5-foot vertical wind tunnel of inlet and outlet openings in a flat plate and in a wing. When an internal-flow system tends to decrease the final velocity of it's wake, the results showed that it should be arranged in series with the propulsive system; the inlet opening should be located at a forward stagnation point; and the outlet opening should be so shaped and located as to recover the kinetic energy of the jet without increasing the drag of other portions of the aircraft. When an internal-flow system tends to increase the final velocity new b's wake, as does a propeller, location of the inlet opening in the boundary layer or in the wake of the wing or in the fuselage may be desirable.

  14. Rebalancing electrolytes in redox flow battery systems

    SciTech Connect

    Chang, On Kok; Pham, Ai Quoc

    2014-12-23

    Embodiments of redox flow battery rebalancing systems include a system for reacting an unbalanced flow battery electrolyte with a rebalance electrolyte in a first reaction cell. In some embodiments, the rebalance electrolyte may contain ferrous iron (Fe.sup.2+) which may be oxidized to ferric iron (Fe.sup.3+) in the first reaction cell. The reducing ability of the rebalance reactant may be restored in a second rebalance cell that is configured to reduce the ferric iron in the rebalance electrolyte back into ferrous iron through a reaction with metallic iron.

  15. Shipborne measurements with a modular multipurpose mobile lidar system for tropospheric and stratospheric aerosol observations

    NASA Astrophysics Data System (ADS)

    Schaefer, Juergen; Schrems, Otto; Beyerle, Georg; Hofer, Bernd; Mildner, Wolfgang; Theopold, Felix A.

    1997-05-01

    In our contribution water vapor and aerosol measurements with a new modular two wavelength Rayleigh Raman lidar instrument are described. A comparison of the data with radiosonde data are shown and the results discussed. The new mobile aerosol Raman lidar (MARL) is able to measure aerosol backscatter and extinction coefficient as well as depolarization in the altitude range 5 to 50 km. The system is operational since July 1996 and participated at the ALBATROSS (atmospheric chemistry and lidar studies above the Atlantic Ocean related to ozone and other trace gases in the tropo and stratosphere) campaign aboard the German research vessel Polarstern on a cruise from Bremerhaven, Germany to Punta Quilla, Argentina in October/November 1996. Key parts of the lidar system include a frequency doubled and tripled Nd:YAG laser, a large receiving telescope mirror (1.15 m diameter) and a sophisticated polychromator. The system's power aperture product is more than 9 Wm2 on each wavelength (532 nm and 355 nm). The instrument is installed in a standard 20 ft ISO container and is operational in polar as well as tropical environments wherever a supply with electrical power is available.

  16. A Mechanical System to Reproduce Cardiovascular Flows

    NASA Astrophysics Data System (ADS)

    Lindsey, Thomas; Valsecchi, Pietro

    2010-11-01

    Within the framework of the "Pumps&Pipes" collaboration between ExxonMobil Upstream Research Company and The DeBakey Heart and Vascular Center in Houston, a hydraulic control system was developed to accurately simulate general cardiovascular flows. The final goal of the development of the apparatus was the reproduction of the periodic flow of blood through the heart cavity with the capability of varying frequency and amplitude, as well as designing the systolic/diastolic volumetric profile over one period. The system consists of a computer-controlled linear actuator that drives hydraulic fluid in a closed loop to a secondary hydraulic cylinder. The test section of the apparatus is located inside a MRI machine, and the closed loop serves to physically separate all metal moving parts (control system and actuator cylinder) from the MRI-compatible pieces. The secondary cylinder is composed of nonmetallic elements and directly drives the test section circulatory flow loop. The circulatory loop consists of nonmetallic parts and several types of Newtonian and non-Newtonian fluids, which model the behavior of blood. This design allows for a periodic flow of blood-like fluid pushed through a modeled heart cavity capable of replicating any healthy heart condition as well as simulating anomalous conditions. The behavior of the flow inside the heart can thus be visualized by MRI techniques.

  17. Improving aerosol interaction with clouds and precipitation in a regional chemical weather modeling system

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Zhang, X.; Gong, S.; Wang, Y.; Xue, M.

    2016-01-01

    A comprehensive aerosol-cloud-precipitation interaction (ACI) scheme has been developed under a China Meteorological Administration (CMA) chemical weather modeling system, GRAPES/CUACE (Global/Regional Assimilation and PrEdiction System, CMA Unified Atmospheric Chemistry Environment). Calculated by a sectional aerosol activation scheme based on the information of size and mass from CUACE and the thermal-dynamic and humid states from the weather model GRAPES at each time step, the cloud condensation nuclei (CCN) are interactively fed online into a two-moment cloud scheme (WRF Double-Moment 6-class scheme - WDM6) and a convective parameterization to drive cloud physics and precipitation formation processes. The modeling system has been applied to study the ACI for January 2013 when several persistent haze-fog events and eight precipitation events occurred.

    The results show that aerosols that interact with the WDM6 in GRAPES/CUACE obviously increase the total cloud water, liquid water content, and cloud droplet number concentrations, while decreasing the mean diameters of cloud droplets with varying magnitudes of the changes in each case and region. These interactive microphysical properties of clouds improve the calculation of their collection growth rates in some regions and hence the precipitation rate and distributions in the model, showing 24 to 48 % enhancements of threat score for 6 h precipitation in almost all regions. The aerosols that interact with the WDM6 also reduce the regional mean bias of temperature by 3 °C during certain precipitation events, but the monthly means bias is only reduced by about 0.3 °C.

  18. Real-time characterization of the size and chemical composition of individual particles in ambient aerosol systems in Riverside, California

    SciTech Connect

    Noble, C.A.; Prather, K.A.

    1995-12-31

    Atmospheric aerosols, although ubiquitous, are highly diverse and continually fluctuating systems. A typical aerosol system may consist of particles with diameters between {approximately}0.002 {mu}m and {approximately}200 {mu}m. Even in rural or pristine areas, atmospheric particle concentration is significant, with concentrations up to 10{sup 8} particles/cm{sup 3} not being uncommon. Chemical composition of atmospheric particles vary from simple water droplets or acidic ices to soot particles and cigarette smoke. Due to changes in atmospheric conditions, processes such as nucleation, coagulation or heterogeneous chemistry may effect both physical and chemical properties of individual particles over relatively short time intervals. Recently, aerosol measurement techniques are focusing on determining the size and/or chemical composition of individual aerosol particles. This research group has recently developed aerosol time-of-flight mass spectrometry (ATOFMS), a technique which allows for real-time determination of the size and chemical composition of individual aerosol particles. Single particle measurements are performed in one instrument using dual laser aerodynamic particle sizing and time-of-flight mass spectrometry. Aerosol-time-of-flight mass spectrometry is briefly described in several other abstracts in this publication.

  19. Impact of Interactive Aerosol on the African Easterly Jet in the NASA GEOS-5 Global Forecasting System

    NASA Technical Reports Server (NTRS)

    Reale, O.; Lau, K. M.; da Silva, A.

    2010-01-01

    The real-time treatment of interactive realistically varying aerosol in a global operational forecasting system, as opposed to prescribed (fixed or climatologically varying) aerosols, is a very difficult challenge that only recently begins to be addressed. Experiment results from a recent version of the NASA GEOS-5 forecasting system, inclusive of interactive aerosol treatment, are presented in this work. Four sets of 30 5-day forecasts are initialized from a high quality set of analyses previously produced and documented to cover the period from 15 August to 16 September 2006, which corresponds to the NASA African Monsoon Multidisciplinary Analysis (NAMMA) observing campaign. The four forecast sets are at two different horizontal resolutions and with and without interactive aerosol treatment. The net impact of aerosol, at times in which there is a strong dust outbreak, is a temperature increase at the dust level and decrease in the near-surface levels, in complete agreement with previous observational and modeling studies. Moreover, forecasts in which interactive aerosols are included depict an African Easterly (AEJ) at slightly higher elevation, and slightly displace northward, with respect to the forecasts in which aerosols are not include. The shift in the AEJ position goes in the direction of observations and agrees with previous results.

  20. Aerosol distribution apparatus

    DOEpatents

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  1. Resource Prospector Propulsion System Cold Flow Testing

    NASA Technical Reports Server (NTRS)

    Williams, Hunter; Holt, Kim; Addona, Brad; Trinh, Huu

    2015-01-01

    Resource Prospector (RP) is a NASA mission being led by NASA Ames Research Center with current plans to deliver a scientific payload package aboard a rover to the lunar surface. As part of an early risk reduction activity, Marshall Space Flight Center (MSFC) and Johnson Space Flight Center (JSC) have jointly developed a government-version concept of a lunar lander for the mission. The spacecraft consists of two parts, the lander and the rover which carries the scientific instruments. The lander holds the rover during launch, cruise, and landing on the surface. Following terminal descent and landing the lander portion of the spacecraft become dormant after the rover embarks on the science mission. The lander will be equipped with a propulsion system for lunar descent and landing, as well as trajectory correction and attitude control maneuvers during transit to the moon. Hypergolic propellants monomethyl hydrazine and nitrogen tetroxide will be used to fuel sixteen 70-lbf descent thrusters and twelve 5-lbf attitude control thrusters. A total of four metal-diaphragm tanks, two per propellant, will be used along with a high-pressure composite-overwrapped pressure vessel for the helium pressurant gas. Many of the major propulsion system components are heritage missile hardware obtained by NASA from the Air Force. In parallel with the flight system design activities, a simulated propulsion system based on flight drawings was built for conducting a series of water flow tests to characterize the transient fluid flow of the propulsion system feed lines and to verify the critical operation modes such as system priming, waterhammer, and crucial mission duty cycles. The primary objective of the cold flow testing was to simulate the RP propulsion system fluid flow operation through water flow testing and to obtain data for anchoring analytical models. The models will be used to predict the transient and steady state flow behaviors in the actual flight operations. All design and

  2. Information flow in heterogeneously interacting systems.

    PubMed

    Yamaguti, Yutaka; Tsuda, Ichiro; Takahashi, Yoichiro

    2014-02-01

    Motivated by studies on the dynamics of heterogeneously interacting systems in neocortical neural networks, we studied heterogeneously-coupled chaotic systems. We used information-theoretic measures to investigate directions of information flow in heterogeneously coupled Rössler systems, which we selected as a typical chaotic system. In bi-directionally coupled systems, spontaneous and irregular switchings of the phase difference between two chaotic oscillators were observed. The direction of information transmission spontaneously switched in an intermittent manner, depending on the phase difference between the two systems. When two further oscillatory inputs are added to the coupled systems, this system dynamically selects one of the two inputs by synchronizing, selection depending on the internal phase differences between the two systems. These results indicate that the effective direction of information transmission dynamically changes, induced by a switching of phase differences between the two systems. PMID:24465282

  3. Monitoring Aerosol Optical Properties in the ABL, Using Lidar System and Sunphotometer in Buenos Aires, Argentina

    NASA Astrophysics Data System (ADS)

    Pallotta, J.; Pawelko, E.; Otero, L.; Ristori, P.; D'Elia, R.; Gonzalez, F.; Dworniczak, J.; Vilar, O.; Quel, E.

    2009-03-01

    At the Lasers and Applications Research Center (CEILAP, CITEFA-CONICET, (34°33' S, 58°30' W), located in an industrial suburb of the metropolitan area (Villa Martelli, Buenos Aires, Argentina), operates a multiwavelength lidar, based on a Nd:Yag laser (Continuum Surelite III P-IV). This system emits in 1064, 532 and 355 nm simultaneously (10 Hz, 600 mJ @ 1064 nm) and allows the monitoring of the optical aerosols properties in the atmospheric boundary layer (ABL). On the same experimental site, an AERONET sunphotometer provides the AOT value. An analysis of boundary layer behaviour in some relevant days of March, from the years 2004 to 2006 is presented. On the days analyzed, no aerosols events and clouds were registered over the ABL. Evolutions of some characteristics of the ABL are presented, such as the height of the boundary layer, height of entrainment zone (EZ) and the entrainment flux ratio.

  4. Alternatives for Laboratory Measurement of Aerosol Samples from the International Monitoring System of the CTBT

    NASA Astrophysics Data System (ADS)

    Miley, H.; Forrester, J. B.; Greenwood, L. R.; Keillor, M. E.; Eslinger, P. W.; Regmi, R.; Biegalski, S.; Erikson, L. E.

    2013-12-01

    The aerosol samples taken from the CTBT International Monitoring Systems stations are measured in the field with a minimum detectable concentration (MDC) of ~30 microBq/m3 of Ba-140. This is sufficient to detect far less than 1 kt of aerosol fission products in the atmosphere when the station is in the plume from such an event. Recent thinking about minimizing the potential source region (PSR) from a detection has led to a desire for a multi-station or multi-time period detection. These would be connected through the concept of ';event formation', analogous to event formation in seismic event study. However, to form such events, samples from the nearest neighbors of the detection would require re-analysis with a more sensitive laboratory to gain a substantially lower MDC, and potentially find radionuclide concentrations undetected by the station. The authors will present recent laboratory work with air filters showing various cost effective means for enhancing laboratory sensitivity.

  5. Interesting Scientific Questions Regarding Interactions in the Gas-aerosol-cloud System

    NASA Technical Reports Server (NTRS)

    Tabazadeh, Azadeh

    2002-01-01

    The growth of human population and their use of land, food and energy resources affect the Earth's atmosphere, biosphere and oceans in a complex manner. Many important questions in earth sciences today deal with issues regarding the impact of human activities on our immediate and future environment, ranging in scope from local (i.e. air pollution) to global (i.e. global warming) scale problems. Because the mass of the Earth's atmosphere is negligible compare to that found in the oceans and the biosphere, the atmosphere can respond quickly to natural and/or manmade perturbations. For example, seasonal 'ozone hole' formation in the Antarctic is a result of manmade CFC emissions in just the last 40 years. Also, the observed rise in global temperatures (known as global warming) is linked to a rapid increase in carbon dioxide and other greenhouse gas concentrations (emitted primarily by combustion processes) over the last century. The Earth's atmosphere is composed of a mixture of gases, aerosol and cloud particles. Natural and anthropogenic emissions of gases and aerosols affect the composition of the Earth's atmosphere. Changes in the chemical and physical makeup of the atmosphere can influence how the Earth will interact with the incoming solar radiation and the outgoing infrared radiation and vise versa. While, some perturbations are short-lived, others are long-lived and can affect the Earth's global climate and chemistry in many decades to come, In order to be able to separate the natural effects from anthropogenic ones, it is essential that we understand the basic physics and chemistry of interactions in the gas-aerosol-cloud system in the Earth's atmosphere. The important physics and chemistry that takes place in the coupled gas-aerosol-cloud system as it relates to aircraft observations are discussed.

  6. Are there statistical links between the direction of European weather systems and ENSO, the solar cycle or stratospheric aerosols?

    PubMed

    Laken, Benjamin A; Stordal, Frode

    2016-02-01

    The Hess Brezowsky Großwetterlagen (HBGWL) European weather classification system, accumulated over a long period (more than 130 years), provides a rare opportunity to examine the impact of various factors on regional atmospheric flow. We have used these data to examine changes in the frequency (days/month) of given weather systems direction (WSD) during peak phases in the North Atlantic Oscillation (NAO), El Niño Southern Oscillation (ENSO), solar cycle (SC) and peaks in stratospheric aerosol optical depth (AOD) with superposed epoch analysis and Monte Carlo significance testing. We found highly significant responses to the NAO consistent with expectations: this signal confirmed the utility of the HBGWL data for this type of analysis and provided a benchmark of a clear response. WSD changes associated with ENSO, SC and AOD were generally within the ranges expected from random samples. When seasonal restrictions were added the results were similar, however, we found one clearly significant result: an increase in southerly flow of 2.6±0.8 days/month (p=1.9×10(-4)) during boreal summertime in association with El Niño. This result supports the existence of a robust teleconnection between the ENSO and European weather. PMID:26998314

  7. Are there statistical links between the direction of European weather systems and ENSO, the solar cycle or stratospheric aerosols?

    PubMed Central

    2016-01-01

    The Hess Brezowsky Großwetterlagen (HBGWL) European weather classification system, accumulated over a long period (more than 130 years), provides a rare opportunity to examine the impact of various factors on regional atmospheric flow. We have used these data to examine changes in the frequency (days/month) of given weather systems direction (WSD) during peak phases in the North Atlantic Oscillation (NAO), El Niño Southern Oscillation (ENSO), solar cycle (SC) and peaks in stratospheric aerosol optical depth (AOD) with superposed epoch analysis and Monte Carlo significance testing. We found highly significant responses to the NAO consistent with expectations: this signal confirmed the utility of the HBGWL data for this type of analysis and provided a benchmark of a clear response. WSD changes associated with ENSO, SC and AOD were generally within the ranges expected from random samples. When seasonal restrictions were added the results were similar, however, we found one clearly significant result: an increase in southerly flow of 2.6±0.8 days/month (p=1.9×10−4) during boreal summertime in association with El Niño. This result supports the existence of a robust teleconnection between the ENSO and European weather. PMID:26998314

  8. Atmospheric Aerosol Sampling with Unmanned Aircraft Systems (UAS) in Alaska: Instrument Development, Payload Integration, and Measurement Campaigns

    NASA Astrophysics Data System (ADS)

    Barberie, S. R.; Saiet, E., II; Hatfield, M. C.; Cahill, C. F.

    2014-12-01

    Atmospheric aerosols remain one of biggest variables in understanding global climate. The number of feedback loops involved in aerosol processes lead to nonlinear behavior at the systems level, making confident modeling and prediction difficult. It is therefore important to ground-truth and supplement modeling efforts with rigorous empirical measurements. To this end, the Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) at the University of Alaska Fairbanks has developed a new cascade DRUM-style impactor to be mounted aboard a variety of unmanned aircraft and work in tandem with an optical particle counter for the routine collection of atmospheric aerosols. These UAS-based aerosol samplers will be employed for measurement campaigns in traditionally hazardous conditions such as volcanic plumes and over forest fires. Here we report on the development and laboratory calibration of the new instrument, the integration with UAS, and the vertical profiling campaigns being undertaken.

  9. Methods for measuring performance of vehicle cab air cleaning systems against aerosols and vapours.

    PubMed

    Bémer, D; Subra, I; Régnier, R

    2009-06-01

    Vehicle cabs equipped with an effective air cleaning and pressurization system, fitted to agricultural and off-road machineries, isolate drivers from the polluted environment, in which they are likely to work. These cabs provide protection against particulate and gaseous pollutants generated by these types of work activities. Two laboratory methods have been applied to determining the performance characteristics of two cabs of different design, namely, optical counting-based measurement of a potassium chloride (KCl) aerosol and fluorescein aerosol-based tracing. Results of cab confinement efficiency measurements agreed closely for these two methods implemented in the study. Measurements showed that high confinement efficiencies can be achieved with cabs, which are properly designed in ventilation/cleaning/airtightness terms. We also noted the importance of filter mounting airtightness, in which the smallest defect is reflected by significant degradation in cab performance. Determination of clean airflow rate by monitoring the decrease in test aerosol concentration in the test chamber gave excellent results. This method could represent an attractive alternative to methods involving gas tracing or air velocity measurement at blowing inlets. PMID:19406910

  10. A model aerosol exposure system for induction of porcine Haemophilus pleuropneumonia.

    PubMed Central

    Sebunya, T N; Saunders, J R; Osborne, A D

    1983-01-01

    One group of six pigs and another group of three pigs were separately exposed in a polyethylene enclosed chamber for ten minutes, respectively, to Haemophilus pleuropneumoniae serotype 1 and Bacillus subtilis aerosols generated by an ultrasonic nebulizer. Haemophilus pleuropneumoniae and B. subtilis were deposited throughout the lungs immediately following aerosol exposure. The number of H. pleuropneumoniae and B. subtilis deposited varied within and between lungs in each group. The mean numbers of both organisms deposited in the posterior (caudal and accessory) lobes were significantly greater than those in the anterior (cranial and middle) lobes (P less than 0.001). The four principals that received H. pleuropneumoniae aerosols and the two contact controls developed fatal fibrinous pneumonia which simulated that seen in natural infections. Since this exposure system consistently resulted in clinical disease it has good potential as a model for the study of pathogenesis of the disease and more specifically for the evaluation of vaccines. Images Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. PMID:6403208

  11. Global Monitoring of Clouds and Aerosols Using a Network of Micro-Pulse Lidar Systems

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Campbell, James R.; Spinhirne, James D.; Scott, V. Stanley

    2000-01-01

    Long-term global radiation programs, such as AERONET and BSRN, have shown success in monitoring column averaged cloud and aerosol optical properties. Little attention has been focused on global measurements of vertically resolved optical properties. Lidar systems are the preferred instrument for such measurements. However, global usage of lidar systems has not been achieved because of limits imposed by older systems that were large, expensive, and logistically difficult to use in the field. Small, eye-safe, and autonomous lidar systems are now currently available and overcome problems associated with older systems. The first such lidar to be developed is the Micro-pulse lidar System (MPL). The MPL has proven to be useful in the field because it can be automated, runs continuously (day and night), is eye-safe, can easily be transported and set up, and has a small field-of-view which removes multiple scattering concerns. We have developed successful protocols to operate and calibrate MPL systems. We have also developed a data analysis algorithm that produces data products such as cloud and aerosol layer heights, optical depths, extinction profiles, and the extinction-backscatter ratio. The algorithm minimizes the use of a priori assumptions and also produces error bars for all data products. Here we present an overview of our MPL protocols and data analysis techniques. We also discuss the ongoing construction of a global MPL network in conjunction with the AERONET program. Finally, we present some early results from the MPL network.

  12. Stratospheric aerosol and gas experiment III (SAGE III) aerosol and trace gas measurements for Earth Observing System (EOS)

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.; Chu, W. P.; Zawodny, J. M.; Mauldin, L. E.; Mcmaster, L. R.

    1991-01-01

    The SAGE III instrument, the latest in a series of satellite-based instruments employing the self-calibrating solar occultation technique to monitor aerosols and trace gases in the atmosphere, and potential contributions to monitoring global change and other EOS objectives are described. Uses of these data are illustrated with SAGE I and II long-term ozone, aerosol, and water vapor data. The SAGE III instrument will improve the SAM II and SAGE data products with greater overall accuracy, and will provide the ability to extend these measurements over a greater height range. SAGE III will provide long-term self-calibrating global data sets from the midtroposphere to mesosphere, which will contribute greatly to the quantification and understanding of global change.

  13. ANALYSIS OF FLOW THROUGH A HUMAN ORAL MODEL FOR USE IN INHALATION TOXICOLOGY AND AEROSOL THERAPY PROTOCOLS

    EPA Science Inventory


    RATIONALE
    Understanding the transport and deposition of inhaled aerosols is of fundamental importance to inhalation toxicology and aerosol therapy. Herein, we focus on the development of a computer based oral morphology and related computational fluid dynamics (CFD) studi...

  14. Secondary Organic Aerosol Formation from Ambient Air in an Oxidation Flow Reactor at GoAmazon2014/5

    NASA Astrophysics Data System (ADS)

    Palm, Brett B.; de Sa, Suzane S.; Campuzano-Jost, Pedro; Day, Douglas A.; Hu, Weiwei; Seco, Roger; Park, Jeong-Hoo; Guenther, Alex; Kim, Saewung; Brito, Joel; Wurm, Florian; Artaxo, Paulo; Yee, Lindsay; Isaacman-VanWertz, Gabrial; Goldstein, Allen; Newburn, Matt K.; Lizabeth Alexander, M.; Martin, Scot T.; Brune, William H.; Jimenez, Jose L.

    2016-04-01

    During GoAmazon2014/5, ambient air was exposed to controlled concentrations of OH or O3 in situ using an oxidation flow reactor (OFR). Oxidation ranged from hours-several weeks of aging. Oxidized air was sampled by several instruments (e.g., HR-AMS, ACSM, PTR-TOF-MS, SMPS, CCN) at both the T3 site (IOP1: Feb 1-Mar 31, 2014, and IOP2: Aug 15-Oct 15, 2014) and T2 site (between IOPs and into 2nd IOP). The oxidation of ambient air in the OFR led to substantial and variable secondary organic aerosol (SOA) formation from any SOA-precursor gases, known and unknown, that entered the OFR. In general, more SOA was produced during the nighttime than daytime, suggesting that SOA-precursor gases were found in relatively higher concentrations at night. Similarly, more SOA was formed in the dry season (IOP2) than wet season (IOP1). The maximum amount of SOA produced during nighttime from OH oxidation ranged from less than 1 μg/m3 on some nights to greater than 10 μg/m3 on other nights. O3 oxidation of ambient air also led to SOA formation, although several times less than from OH oxidation. The amount of SOA formation sometimes, but not always, correlated with measured gas-phase biogenic and/or anthropogenic SOA precursors (e.g., SV-TAG sesquiterpenes, PTR-TOFMS aromatics, isoprene, and monoterpenes). The SOA mass formed in the OFR from OH oxidation was up to an order of magnitude larger than could be explained from aerosol yields of measured primary VOCs. This along with measurements from previous campaigns suggests that most SOA was formed from intermediate S/IVOC sources (e.g., VOC oxidation products, evaporated POA, or direct emissions). To verify the SOA yields of VOCs under OFR experimental conditions, atmospherically-relevant concentrations of several VOCs were added individually into ambient air in the OFR and oxidized by OH or O3. SOA yields in the OFR were similar to published chamber yields. Preliminary PMF factor analysis showed production of secondary factors in

  15. A study of aerosol optical properties using a lightweight optical particle spectrometer and sun photometer from an unmanned aerial system

    NASA Astrophysics Data System (ADS)

    Telg, H.; Murphy, D. M.; Bates, T. S.; Johnson, J. E.; Gao, R. S.

    2015-12-01

    A miniaturized printed optical particle spectrometer (POPS) and sun photometer (miniSASP) have been developed recently for unmanned aerial systems (UAS) and balloon applications. Here we present the first scientific data recorded by the POPS and miniSASP from a Manta UAS during a field campaign on Svalbard, Norway, in April 2015. As part of a payload composed of five different aerosol instruments (absorption photometer, condensation particle counter, filter sampler, miniSASP and POPS) we collected particle size distributions, the optical depth (OD) and the sky brightness from 0 to 3000 m altitude. The complementary measurement approaches of the miniSASP and POPS allow us to calculate aerosol optical properties such as the aerosol optical depth and the angstrom exponent or the asymmetry parameter independently. We discuss deviation between results with respect to aerosol properties, e.g. hygroscopicity and absorption, as well as instrumental limitations.

  16. High-Throughput Synthesis of Lignin Particles (∼30 nm to ∼2 μm) via Aerosol Flow Reactor: Size Fractionation and Utilization in Pickering Emulsions.

    PubMed

    Ago, Mariko; Huan, Siqi; Borghei, Maryam; Raula, Janne; Kauppinen, Esko I; Rojas, Orlando J

    2016-09-01

    An aerosol flow reactor was used for the first time for high-throughput, high yield synthesis of spherical lignin particles with given inherent hydrophilicity, depending on the precursor biomolecule. In situ fractionation via Berner type impactor afforded populations with characteristic sizes ranging from ∼30 nm to 2 μm. The as-produced, dry lignin particles displayed excellent mechanical integrity, even after redispersion under high shear in either mineral oil or water. They were effective in the stabilization of oil-in-water (O/W) Pickering emulsions with tunable droplet size, depending on the dimension of the lignin particles used for emulsification. The emulsion stability correlated with particle concentration as well as the respective lignin type. For the O/W emulsions stabilized with the more hydrophilic lignin particles, negligible changes in phase separation via Ostwald ripening and coalescence were observed over a period of time of more than two months. Together with the fact that the lignin particle concentrations used in emulsification were as low as 0.1%, our results reveal a remarkable ability to endow emulsified systems with high colloidal stability. Overall, we offer a new, high-yield, scalable nanomanufacturing approach to producing dry spherical lignin particles with size control and high production capacity. A number of emerging applications for these organic particles can be envisioned and, as a proof-of-concept, we illustrate here surfactant-free emulsification. PMID:27538013

  17. Nd:YAG and ruby based lidar systems for remote sensing of atmospheric aerosols

    NASA Technical Reports Server (NTRS)

    Fuller, W. H., Jr.

    1985-01-01

    The application of solid-state lasers to the study of stratospheric and tropospheric aerosols is analyzed. A 48-inch mobile lidar which operates in the 0.6943, 1.06, 0.3472, and 0.5300 micron ranges is utilized to monitor the stratosphere. The detectors of the system consist of photomultipliers, and the dual-channel, computer-based data-acquisition-system which provides on-line plotting of scattering ratio profiles. The components of the 14-inch aperture, dual-wavelength airborne lidar system that operates with ruby and Nd:YAG transmitters are described. An 8-inch, down-looking airborne lidar with silicon diode or photomultiplier detectors was developed. The capabilities of the system alone and when combined with the 14-inch lidar are discussed. Examples of the data provided by the three lidar systems are presented, revealing the reliability and operational efficiency of the systems.

  18. Aerodynamic Flow Field Measurements for Automotive Systems

    NASA Technical Reports Server (NTRS)

    Hepner, Timothy E.

    1999-01-01

    The design of a modern automotive air handling system is a complex task. The system is required to bring the interior of the vehicle to a comfortable level in as short a time as possible. A goal of the automotive industry is to predict the interior climate of an automobile using advanced computational fluid dynamic (CFD) methods. The development of these advanced prediction tools will enable better selection of engine and accessory components. The goal of this investigation was to predict methods used by the automotive industry. To accomplish this task three separate experiments were performed. The first was a laboratory setup where laser velocimeter (LV) flow field measurements were made in the heating and air conditioning unit of a Ford Windstar. The second involved flow field measurements in the engine compartment of a Ford Explorer, with the engine running idle. The third mapped the flow field exiting the center dashboard panel vent inside the Explorer, while the circulating fan operated at 14 volts. All three experiments utilized full-coincidence three-component LV systems. This enabled the mean and fluctuating velocities to be measured along with the Reynolds stress terms.

  19. Run-time Ink Stability in Pneumatic Aerosol Jet Printing Using a Split Stream Solvent Add Back System

    NASA Astrophysics Data System (ADS)

    Wadhwa, Arjun

    Aerosol Jet printing is a non-contact process capable of printing nano-ink patterns on conformal and flexible surfaces. Aqueous or solvent nano-inks are pneumatically atomized by the flow of nitrogen gas. The flow of atomizing gas into and out of the cup leads to evaporation and removal of volatile solvent(s). As the solid loading fraction of the ink increases, the rheological changes eventually lead to instabilities in print output. A potential solution to this problem is to moisten the atomizing ink by running it through a bubbler. In this study, neat co-solvent solutions of ethanol and ethylene glycol at 85: 15 and 30:70 mixing ratios were atomized using nitrogen flow rates ranging from 600 to 1000 ccm. It was observed that ethanol, being the more volatile solvent, was depleted from the neat solution. When using a bubbler solvent add-back system, an excessive amount of ethanol was returned to the neat solution. The rate of solvent loss from an ethanol rich neat solution (80%) was higher compared to an ethylene glycol rich neat solution. A mixture of dry and wet (ethanol moistened) nitrogen gas was used to equalize the rate of ethanol evaporation. Ethanol equilibrium in neat solutions with higher ethylene glycol loading (70%) was achieved with a 40-60% wet nitrogen component while neat solutions with higher ethanol loading (85%) were stable with 85 -90% wet nitrogen gas. The results were validated with copper nano ink with similar co-solvent ratios. The solid content of the ink remained constant over four hours of printing when the optimal dry: wet nitrogen gas ratios were used. Copper ink with 85% ethanol being atomized at 1000 ccm exhibited increase in copper loading (3%) despite the dry: wet solvent add back system.

  20. Modular lidar systems for high-resolution 4-dimensional measurements of water vapor, temperature, and aerosols

    NASA Astrophysics Data System (ADS)

    Behrendt, Andreas; Wagner, Gerd; Petrova, Anna; Shiler, Max; Pal, Sandip; Schaberl, Thorsten; Wulfmeyer, Volker

    2005-01-01

    Three lidar systems are currently in development at University of Hohenheim. A water vapor lidar based on the differential absorption lidar (DIAL) technology working near 815 or 935 nm, a temperature and aerosol lidar employing the rotational Raman technique at 355 nm, and an aerosol lidar working with eye-safe laser radiation near 1.5 μm. The transmitters of these three systems are based on an injection-seeded, diode laser pumped Nd:YAG laser with an average power of 100 W at 1064 nm and a repetition rate of 250 Hz. This laser emits a nearly Gaussian-shaped beam which permits frequency-doubling and tripling with high efficiencies. The frequency-doubled 532-nm radiation is employed for pumping a Ti:Sapphire ring-resonator which will be used for DIAL water vapor measurements. In a second branch, a Cr4+:YAG crystal is pumped with the 1064-nm radiation to reach 1400 to 1500 nm for eye-safe monitoring of aerosol particles and clouds. The 532 and 1064 nm radiation are also used for backscatter lidar observations. Frequency tripling gives 355-nm radiation for measurements of temperature with the rotational Raman technique and particle extinction and particle backscattering coefficients in the UV. High transmitter power and effective use of the received signals will allow scanning operation of these three lidar systems. The lidar transmitters and detectors are designed as modules which can be combined for simultaneous measurements with one scanning telescope unit in a ground-based mobile container. Alternatively, they can be connected to different Nd:YAG pump lasers and to telescope units on separate platforms.

  1. Comparison of secondary organic aerosol formed with an aerosol flow reactor and environmental reaction chambers: effect of oxidant concentration, exposure time and seed particles on chemical composition and yield

    DOE PAGESBeta

    Lambe, A. T.; Chhabra, P. S.; Onasch, T. B.; Brune, W. H.; Hunter, J. F.; Kroll, J. H.; Cummings, M. J.; Brogan, J. F.; Parmar, Y.; Worsnop, D. R.; et al

    2014-12-02

    We performed a systematic intercomparison study of the chemistry and yields of SOA generated from OH oxidation of a common set of gas-phase precursors in a Potential Aerosol Mass (PAM) continuous flow reactor and several environmental chambers. In the flow reactor, SOA precursors were oxidized using OH concentrations ranging from 2.0×108 to 2.2×1010 molec cm-3 over exposure times of 100 s. In the environmental chambers, precursors were oxidized using OH concentrations ranging from 2×106 to 2×107 molec cm-3 over exposure times of several hours. The OH concentration in the chamber experiments is close to that found in the atmosphere, butmore » the integrated OH exposure in the flow reactor can simulate atmospheric exposure times of multiple days compared to chamber exposure times of only a day or so. A linear correlation analysis of the mass spectra (m=0.91–0.92, r2=0.93–0.94) and carbon oxidation state (m=1.1, r2=0.58) of SOA produced in the flow reactor and environmental chambers for OH exposures of approximately 1011 molec cm-3 s suggests that the composition of SOA produced in the flow reactor and chambers is the same within experimental accuracy as measured with an aerosol mass spectrometer. This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors, rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed particles are

  2. Airborne water vapor DIAL system and measurements of water and aerosol profiles

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.

    1991-01-01

    The Lidar Applications Group at NASA Langley Research Center has developed a differential absorption lidar (DIAL) system for the remote measurement of atmospheric water vapor (H2O) and aerosols from an aircraft. The airborne H2O DIAL system is designed for extended flights to perform mesoscale investigations of H2O and aerosol distributions. This DIAL system utilizes a Nd:YAG-laser-pumped dye laser as the off-line transmitter and a narrowband, tunable Alexandrite laser as the on-line transmitter. The dye laser has an oscillator/amplifier configuration which incorporates a grating and prism in the oscillator cavity to narrow the output linewidth to approximately 15 pm. This linewidth can be maintained over the wavelength range of 725 to 730 nm, and it is sufficiently narrow to satisfy the off-line spectral requirements. In the Alexandrite laser, three intracavity tuning elements combine to produce an output linewidth of 1.1 pm. These spectral devices include a five-plate birefringent tuner, a 1-mm thick solid etalon and a 1-cm air-spaced etalon. A wavelength stability of +/- 0.35 pm is achieved by active feedback control of the two Fabry-Perot etalons using a frequency stabilized He-Ne laser as a wavelength reference. The three tuning elements can be synchronously scanned over a 150 pm range with microprocessor-based scanning electronics. Other aspects of the DIAL system are discussed.

  3. The effect of organic aerosol material on aerosol reactivity towards ozone

    NASA Astrophysics Data System (ADS)

    Batenburg, Anneke; Gaston, Cassandra; Thornton, Joel; Virtanen, Annele

    2015-04-01

    After aerosol particles are formed or emitted into the atmosphere, heterogeneous reactions with gaseous oxidants cause them to 'age'. Aging can change aerosol properties, such as the hygroscopicity, which is an important parameter in how the particles scatter radiation and form clouds. Conversely, heterogeneous reactions on aerosol particles play a significant role in the cycles of various atmospheric trace gases. Organic compounds, a large part of the total global aerosol matter, can exist in liquid or amorphous (semi)solid physical phases. Different groups have shown that reactions with ozone (O3) can be limited by bulk diffusion in organic aerosol, particularly in viscous, (semi)solid materials, and that organic coatings alter the surface interactions between gas and aerosol particles. We aim to better understand and quantify how the viscosity and phase of organic aerosol matter affect gas-particle interactions. We have chosen the reaction of O3 with particles composed of a potassium iodide (KI) core and a variable organic coating as a model system. The reaction is studied in an aerosol flow reactor that consists of a laminar flow tube and a movable, axial injector for the injection of O3. The aerosol-containing air is inserted at the tube's top. The interaction length (and therefore time), between the particles and the O3 can be varied by moving the injector. Alternatively, the production of aerosol particles can be modulated. The remaining O3 concentration is monitored from the bottom of the tube and particle concentrations are measured simultaneously, which allows us to calculate the reactive uptake coefficient γ. We performed exploratory experiments with internally mixed KI and polyethylene glycol (PEG) particles at the University of Washington (UW) in a setup with a residence time around 50 s. Aerosol particles were generated in an atomizer from solutions with varying concentrations of KI and PEG and inserted into the flow tube after they were diluted and

  4. Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    m, PM10=1.1 μg m-3; estimated coefficient of light scattering by particulate matter, σep, at 570 nm=12 Mm-1). (b) High aerosol concentration (PM2.5=43.9 μg m-3; PM10=83.4 μg m-3; estimated σep at 570 nm=245 Mm-1) (reproduced by permission of National Park Service, 2002). Although comprising only a small fraction of the mass of Earth's atmosphere, aerosol particles are highly important constituents of the atmosphere. Special interest has focused on aerosols in the troposphere, the lowest part of the atmosphere, extending from the land or ocean surface typically to ˜8 km at high latitudes, ˜12 km in mid-latitudes, and ˜16 km at low latitudes. That interest arises in large part because of the importance of aerosol particles in geophysical processes, human health impairment through inhalation, environmental effects through deposition, visibility degradation, and influences on atmospheric radiation and climate.Anthropogenic aerosols are thought to exert a substantial influence on Earth's climate, and the need to quantify this influence has sparked much of the current interest in and research on tropospheric aerosols. The principal mechanisms by which aerosols influence the Earth radiation budget are scattering and absorbing solar radiation (the so-called "direct effects") and modifying clouds and precipitation, thereby affecting both radiation and hydrology (the so-called "indirect effects"). Light scattering by aerosols increases the brightness of the planet, producing a cooling influence. Light-absorbing aerosols such as black carbon exert a warming influence. Aerosols increase the reflectivity of clouds, another cooling influence. These radiative influences are quantified as forcings, where a forcing is a perturbation to the energy balance of the atmosphere-Earth system, expressed in units of watts per square meter, W m-2. A warming influence is denoted a positive forcing, and a cooling influence, negative. The radiative direct and indirect forcings by

  5. Ice-condenser aerosol tests

    SciTech Connect

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K. )

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between {approximately}0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m{sup 3}/s resulted in stable thermal stratification whereas flows less than 0.1 m{sup 3}/s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs.

  6. Fluid flow dynamics in MAS systems

    NASA Astrophysics Data System (ADS)

    Wilhelm, Dirk; Purea, Armin; Engelke, Frank

    2015-08-01

    The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3 mm-rotor diameter has been analyzed for spinning rates up to 67 kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3 mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7 mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor.

  7. Fluid flow dynamics in MAS systems.

    PubMed

    Wilhelm, Dirk; Purea, Armin; Engelke, Frank

    2015-08-01

    The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3mm-rotor diameter has been analyzed for spinning rates up to 67kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor. PMID:26073599

  8. Flow Induced Electrification of Liquid Insulated Systems.

    NASA Astrophysics Data System (ADS)

    Washabaugh, Andrew Patrick

    1995-01-01

    The transport or motion of semi-insulating liquids has led to flow induced static electrification and catastrophic failures in several industries. While techniques for reducing the hazard have been developed, the roles of seemingly important parameters are poorly understood. The objective of this thesis was to measure and understand the fundamental parameters of the flow electrification process that, together with the laws of electroquasistatics and physicochemical hydrodynamics, can be used to predict the performance of complex flow systems, with particular attention to transformer applications. A rotating cylindrical electrode apparatus, which provided cylindrical Couette flow, was used to simulate flow electrification in an electric power transformer. The apparatus had Shell Diala A transformer oil filling the annulus between coaxial cylindrical stainless steel electrodes that were either bare metal, or covered by a thin copper sheet and/or EHV-Weidmann HiVal pressboard insulation. Extensive experiments characterized the time transient and steady state behavior of the electrification through measurements of the volume charge density, the terminal voltage, and the terminal current as the system was driven out of equilibrium by changes in the flow rate (inner cylinder rotation rates of 100-1400 rpm, Reynolds numbers of 5 times 10^3-5 times 10^5), temperature (15-70 ^circ), insulation moisture content (0.5-20 ppm in the oil), applied voltage (0-2 kV DC), and concentration of the non-ionizable anti-static additive 1,2,3 benzotriazole (BTA, 0-60 ppm). Generally, the electrification increased with flow rate and temperature but the BTA appeared to cause competing effects: it decreased the volume charge density on the liquid side of the interface (by a factor of 4), which reduces the electrification, but also decreased the oil conductivity (by a factor of 10), which enhances the electrification. A critical oil BTA concentration of 5 -8 ppm minimized the electrification

  9. Below-cloud rain scavenging of atmospheric aerosols for aerosol deposition models

    NASA Astrophysics Data System (ADS)

    Chate, D. M.; Murugavel, P.; Ali, K.; Tiwari, S.; Beig, G.

    2011-03-01

    Below-cloud aerosol scavenging is generally estimated from field measurements using advanced instruments that measure changes in aerosol distributions with respect to rainfall. In this study, we discuss various scavenging mechanisms and scavenging coefficients from past laboratory and field measurements. Scavenging coefficients derived from field measurements (representing natural aerosols scavenging) are two orders higher than that of theoretical ones for smaller particles (Dp < 2 μm). Measured size-resolved scavenging coefficients can be served as a better option to the default scavenging coefficient (e.g. a constant of 10-4 s-1 for all size of aerosols, as used in the CALPUFF model) for representing below-cloud aerosol scavenging. We propose scavenging correction parameter (CR) as an exponential function of size-resolved scavenging coefficients, winds and width in the downwind of the source-receptor system. For a wind speed of 3 m s-1, CR decrease with the width in the downwind for particles of diameters Dp < 0.1 μm but CR does not vary much for particles in the accumulation mode (0.1 < Dp < 2 μm). For a typical urban aerosol distribution, assuming 3 m s-1 air-flow in the source-receptor system, 10 km downwind width, 2.84 mm h-1 of rainfall and using aerosol size dependent scavenging coefficients in the CR, scavenging of aerosols is found to be 16% in number and 24% in volume of total aerosols. Using the default scavenging coefficient (10-4 s-1) in the CALPUFF model, it is found to be 64% in both number and volume of total aerosols.

  10. Accretion Flows in Magnetic White Dwarf Systems

    NASA Technical Reports Server (NTRS)

    Imamura, James N.

    2005-01-01

    We received Type A and B funding under the NASA Astrophysics Data Program for the analysis and interpretation of hard x-ray data obtained by the Rossi X-ray Timing Explorer and other NASA sponsored missions for Intermediate Polars (IPS) and Polars. For some targets, optical data was available. We reduced and analyzed the X-ray spectra and the X-ray and optical (obtained at the Cerro Tololo Inter-American Observatory) timing data using detailed shock models (which we constructed) to place constraints on the properties of the accreting white dwarfs, the high energy emission mechanisms of white dwarfs, and the large-scale accretion flows of Polars and IPS. IPS and Polars are white dwarf mass-transfer binaries, members of the larger class of cata,clysmic variables. They differ from the bulk of the cataclysmic variables in that they contain strongly magnetic white dwarfs; the white dwarfs in Polars have B, = 7 to 230 MG and those in IPS have B, less than 10 MG. The IPS and Polars are both examples of funneled accretion flows in strong magnetic field systems. The IPS are similar to x-ray pulsars in that accretion disks form in the systems which are disrupted by the strong stellar magnetic fields of the white dwarfs near the stellar surface from where the plasma is funneled to the surface of the white dwarf. The localized hot spots formed at the footpoints of the funnels coupled with the rotation of the white dwarf leads to coherent pulsed x-ray emission. The Polars offer an example of a different accretion topology; the magnetic field of the white dwarf controls the accretion flow from near the inner Lagrangian point of the system directly to the stellar surface. Accretion disks do not form. The strong magnetic coupling generally leads to synchronous orbital/rotational motion in the Polars. The physical system in this sense resembles the Io/Jupiter system. In both IPS and Polars, pulsed emission from the infrared to x-rays is produced as the funneled flows merge onto the

  11. Traffic Flow Wide-Area Surveillance system

    SciTech Connect

    Allgood, G.O.; Ferrell, R.K.; Kercel, S.W.; Abston, R.A.

    1994-09-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret a large spatial projection of data originating from multiple sensor suites. This concept is the basis for the development of a Traffic Flow Wide-Area Surveillance (TFWAS) system. This paper presents the results of a study by Oak Ridge National Laboratory to define the operational specifications and characteristics, to determine the constraints, and to examine the state of technology of a TFWAS system in terms of traffic management and control. In doing so, the functions and attributes of a TFWAS system are mapped into an operational structure consistent with the Intelligent Vehicle Highway System (IVHS) concept and the existing highway infrastructure. This mapping includes identifying candidate sensor suites and establishing criteria, requirements, and performance measures by which these systems can be graded in their ability and practicality to meet the operational requirements of a TFWAS system. In light of this, issues such as system integration, applicable technologies, impact on traffic management and control, and public acceptance are addressed.

  12. Coaxial-Flow System for Chemical Cytometry

    PubMed Central

    Marc, Paul J.; Sims, Christopher E.; Allbritton, Nancy L.

    2008-01-01

    Over the past decade, chemical cytometry performed by capillary electrophoresis (CE) has become increasingly valuable as a bio-analytical tool to quantify analytes from single cells. However, extensive use of CE-based chemical cytometry has been hindered by the relatively low throughput for the analysis of single adherent cells. In order to overcome the low throughput of CE-based analysis of adherent cells and increase its utility in evaluating cellular attributes, new higher throughput methods are needed. Integration of a coaxial buffer exchange system with CE-based chemical cytometry increased the rate of serial analyses of cells. In the designed system, fluid flow through a tube coaxial to the separation capillary was used to supply electrophoretic buffer to the capillary. This sheath or coaxial fluid was turned off between analysis of cells and on during cell sampling and electrophoresis. Thus, living cells were not exposed to the nonphysiologic electrophoretic buffer prior to lysis. Key parameters of the system such as the relative capillary-sheath positions, buffer flow velocities, and the cell chamber design were optimized. To demonstrate the utility of the system, rat basophilic leukemic cells loaded with Oregon Green and fluorescein were serially lysed and loaded into a capillary. Separation of the contents of 20 cells at a rate of 0.5 cells/min was demonstrated. PMID:17979298

  13. Simulation of water flow in terrestrial systems

    2008-12-18

    ParFlow is a parallel, variabley saturated groundwater flow code that is especially suitable for large scale problem. ParFlow simulates the three-dimensional saturated and variably saturated subsurface flow in heterogeneous porous media in three spatial dimensions. ParFlow's developemt and appkication has been on-ging for more than 10 uear. ParFlow has recently been extended to coupled surface-subsurface flow to enabel the simulation of hillslope runoff and channel routing in a truly integrated fashion. ParFlow simulates the three-dimensionalmore » varably saturated subsurface flow in strongly heterogeneous porous media in three spatial dimension.« less

  14. Measurement of tropospheric aerosol in São Paulo area using a new upgraded Raman LIDAR system

    NASA Astrophysics Data System (ADS)

    Landulfo, Eduardo; Rodrigues, Patrícia F.; da Silva Lopes, Fábio Juliano; Bourayou, Riad

    2012-11-01

    Elastic backscatter LIDAR systems have been used to determine aerosol profile concentration in several areas such as weather, pollution and air quality monitoring. In order to determine the aerosol extinction and backscattering profiles, the Klett inversion method is largely used, but this method suffers from lack of information since there are two unknown variables to be determined using only one measured LIDAR signal, and assumption of the LIDAR ratio (the relation between the extinction and backscattering coefficients) is needed. When a Raman LIDAR system is used, the inelastic backscattering signal is affected by aerosol extinction but not by aerosol backscatter, which allows this LIDAR to uniquely determine extinction and backscattering coefficients without any assumptions or any collocated instruments. The MSP-LIDAR system, set-up in a highly dense suburban area in the city of São Paulo, has been upgraded to a Raman LIDAR, and in its actual 6-channel configuration allows it to monitor elastic backscatter at 355 and 532 nm together with nitrogen and water vapor Raman backscatters at 387nm and 608 nm and 408nm and 660 nm, respectively. Thus, the measurements of aerosol backscattering, extinction coefficients and water vapor mixing ratio in the Planetary Boundary Layer (PBL) are becoming available. The system will provide the important meteorological parameters such as Aerosol Optical Depth (AOD) and will be used for the study of aerosol variations in lower troposphere over the city of São Paulo, air quality monitoring and for estimation of humidity impact on the aerosol optical properties, without any a priori assumption. This study will present the first results obtained with this upgraded LIDAR system, demonstrating the high quality of obtained aerosol and water vapor data. For that purpose, we compared the data obtained with the new MSP-Raman LIDAR with a mobile Raman LIDAR collocated at the Center for Lasers and Applications, Nuclear and Energy Research

  15. The Cloud-Aerosol Transport System (CATS): A New Earth Science Capability for ISS (Invited)

    NASA Astrophysics Data System (ADS)

    McGill, M. J.; Yorks, J. E.; Scott, S.; Kupchock, A.; Selmer, P.

    2013-12-01

    The Cloud-Aerosol Transport System (CATS) is a lidar remote sensing instrument developed for deployment to the International Space Station (ISS). The CATS lidar will provide range-resolved profile measurements of atmospheric aerosol and cloud distributions and properties. The CATS instrument uses a high repetition rate laser operating at three wavelengths (1064, 532, and 355 nm) to derive properties of cloud/aerosol layers including: layer height, layer thickness, backscatter, optical depth, extinction, and depolarization-based discrimination of particle type. The CATS mission was designed to capitalize on the Space Station's unique orbit and facilities to continue existing Earth Science data records, to provide observational data for use in forecast models, and to demonstrate new technologies for use in future missions. The CATS payload will be installed on the Japanese Experiment Module - Exposed Facility (JEM-EF). The payload is designed to operate on-orbit for at least six months, and up to three years. The payload is completed and currently scheduled for a mid-2014 launch. The ISS and, in particular, the JEM-EF, is an exciting new platform for spaceborne Earth observations. The ability to leverage existing aircraft instrument designs coupled with the lower cost possible for ISS external attached payloads permits rapid and cost effective development of spaceborne sensors. The CATS payload is based on existing instrumentation built and operated on the high-altitude NASA ER-2 aircraft. The payload is housed in a 1.5 m x 1 m x 0.8 m volume that attaches to the JEM-EF. The allowed volume limits the maximum size for the collecting telescope to 60 cm diameter. Figure 1 shows a schematic layout of the CATS payload, with the primary instrument components identified. Figure 2 is a photo of the completed payload. CATS payload cut-away view. Completed CATS payload assembly.

  16. GUIDE TO CALCULATING TRANSPORT EFFICIENCY OF AEROSOLS IN OCCUPATIONAL AIR SAMPLING SYSTEMS

    SciTech Connect

    Hogue, M.; Hadlock, D.; Thompson, M.; Farfan, E.

    2013-11-12

    This report will present hand calculations for transport efficiency based on aspiration efficiency and particle deposition losses. Because the hand calculations become long and tedious, especially for lognormal distributions of aerosols, an R script (R 2011) will be provided for each element examined. Calculations are provided for the most common elements in a remote air sampling system, including a thin-walled probe in ambient air, straight tubing, bends and a sample housing. One popular alternative approach would be to put such calculations in a spreadsheet, a thorough version of which is shared by Paul Baron via the Aerocalc spreadsheet (Baron 2012). To provide greater transparency and to avoid common spreadsheet vulnerabilities to errors (Burns 2012), this report uses R. The particle size is based on the concept of activity median aerodynamic diameter (AMAD). The AMAD is a particle size in an aerosol where fifty percent of the activity in the aerosol is associated with particles of aerodynamic diameter greater than the AMAD. This concept allows for the simplification of transport efficiency calculations where all particles are treated as spheres with the density of water (1g cm-3). In reality, particle densities depend on the actual material involved. Particle geometries can be very complicated. Dynamic shape factors are provided by Hinds (Hinds 1999). Some example factors are: 1.00 for a sphere, 1.08 for a cube, 1.68 for a long cylinder (10 times as long as it is wide), 1.05 to 1.11 for bituminous coal, 1.57 for sand and 1.88 for talc. Revision 1 is made to correct an error in the original version of this report. The particle distributions are based on activity weighting of particles rather than based on the number of particles of each size. Therefore, the mass correction made in the original version is removed from the text and the calculations. Results affected by the change are updated.

  17. Impacts of the direct radiative effect of aerosols in numerical weather prediction over Europe using the ALADIN-HIRLAM NWP system

    NASA Astrophysics Data System (ADS)

    Toll, V.; Gleeson, E.; Nielsen, K. P.; Männik, A.; Mašek, J.; Rontu, L.; Post, P.

    2016-05-01

    Aerosol feedbacks are becoming more accepted as physical mechanisms that should be included in numerical weather prediction models in order to improve the accuracy of the weather forecasts. The default set-up in the Aire Limitee Adaptation dynamique Developpement INternational (ALADIN) - High Resolution Limited Area Model (HIRLAM) numerical weather prediction system includes monthly aerosol climatologies to account for the average direct radiative effect of aerosols. This effect was studied using the default aerosol climatology in the system and compared to experiments run using the more up-to-date Max-Planck-Institute Aerosol Climatology version 1 (MACv1), and time-varying aerosol data from the Monitoring Atmospheric Composition and Climate (MACC) reanalysis aerosol dataset. Accounting for the direct radiative effect using monthly aerosol climatologies or near real-time aerosol distributions improved the accuracy of the simulated radiative fluxes and temperature and humidity forecasts in the lower troposphere. However, the dependency of forecast meteorological conditions on the aerosol dataset itself was found to be weak.

  18. A lidar system for remote sensing of aerosols and water vapor from NSTS and Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Delorme, Joseph F.

    1989-01-01

    The Tropical Atmospheric Lidar Observing System (TALOS) is proposed to be developed as a Differential Absorption Lidar (DIAL) system for flight aboard the earth orbiting Space Station Freedom. TALOS will be capable of making high resolution vertical profile measurements of tropospheric water and tropospheric and stratospheric aerosols, clouds and temperature.

  19. 46 CFR 153.358 - Venting system flow capacity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Venting system flow capacity. 153.358 Section 153.358 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS... Venting Systems § 153.358 Venting system flow capacity. (a) The cross-sectional flow area of any...

  20. A high-speed photographic system for flow visualization in a steam turbine

    NASA Technical Reports Server (NTRS)

    Barna, G. J.

    1973-01-01

    A photographic system was designed to visualize the moisture flow in a steam turbine. Good performance of the system was verified using dry turbine mockups in which an aerosol spray simulated, in a rough way, the moisture flow in the turbine. Borescopes and fiber-optic light tubes were selected as the general instrumentation approach. High speed motion-picture photographs of the liquid flow over the stator blade surfaces were taken using stroboscopic lighting. Good visualization of the liquid flow was obtained. Still photographs of drops in flight were made using short duration flash sources. Drops with diameters as small as 30 micrometers (0.0012 in.) could be resolved. In addition, motion pictures of a spray of water simulating the spray off the rotor blades and shrouds were taken at normal framing rates. Specially constructed light tubes containing small tungsten-halogen lamps were used. Sixteen millimeter photography was used in all cases. Two potential problems resulting from the two-phase turbine flow (attenuation and scattering of light by the fog present and liquid accumulation on the borescope mirrors) were taken into account in the photographic system design but not evaluated experimentally.

  1. VLT Data Flow System Begins Operation

    NASA Astrophysics Data System (ADS)

    1999-06-01

    Building a Terabyte Archive at the ESO Headquarters The ESO Very Large Telescope (VLT) is the sum of many sophisticated parts. The site at Cerro Paranal in the dry Atacama desert in Northern Chile is one of the best locations for astronomical observations from the surface of the Earth. Each of the four 8.2-m telescopes is a technological marvel with self-adjusting optics placed in a gigantic mechanical structure of the utmost precision, continuously controlled by advanced soft- and hardware. A multitude of extremely complex instruments with sensitive detectors capture the faint light from distant objects in the Universe and record the digital data fast and efficiently as images and spectra, with a minimum of induced noise. And now the next crucial link in this chain is in place. A few nights ago, following an extended test period, the VLT Data Flow System began providing the astronomers with a steady stream of high-quality, calibrated image and spectral data, ready to be interpreted. The VLT project has entered into a new phase with a larger degree of automation. Indeed, the first 8.2-m Unit Telescope, ANTU, with the FORS1 and ISAAC instruments, has now become a true astronomy machine . A smooth flow of data through the entire system ESO PR Photo 25a/99 ESO PR Photo 25a/99 [Preview - JPEG: 400 x 292 pix - 104k] [Normal - JPEG: 800 x 584 pix - 264k] [High-Res - JPEG: 3000 x 2189 pix - 1.5M] Caption to ESO PR Photo 25a/99 : Simplified flow diagramme for the VLT Data Flow System . It is a closed-loop software system which incorporates various subsystems that track the flow of data all the way from the submission of proposals to storage of the acquired data in the VLT Science Archive Facility. The DFS main components are: Program Handling, Observation Handling, Telescope Control System, Science Archive, Pipeline and Quality Control. Arrows indicate lines of feedback. Already from the start of this project more than ten years ago, the ESO Very Large Telescope was

  2. A consistent prescription of stratospheric aerosol for both radiation and chemistry in the Community Earth System Model (CESM1)

    NASA Astrophysics Data System (ADS)

    Reynolds Neely, Ryan, III; Conley, Andrew J.; Vitt, Francis; Lamarque, Jean-François

    2016-07-01

    Here we describe an updated parameterization for prescribing stratospheric aerosol in the National Center for Atmospheric Research (NCAR) Community Earth System Model (CESM1). The need for a new parameterization is motivated by the poor response of the CESM1 (formerly referred to as the Community Climate System Model, version 4, CCSM4) simulations contributed to the Coupled Model Intercomparison Project 5 (CMIP5) to colossal volcanic perturbations to the stratospheric aerosol layer (such as the 1991 Pinatubo eruption or the 1883 Krakatau eruption) in comparison to observations. In particular, the scheme used in the CMIP5 simulations by CESM1 simulated a global mean surface temperature decrease that was inconsistent with the GISS Surface Temperature Analysis (GISTEMP), NOAA's National Climatic Data Center, and the Hadley Centre of the UK Met Office (HADCRUT4). The new parameterization takes advantage of recent improvements in historical stratospheric aerosol databases to allow for variations in both the mass loading and size of the prescribed aerosol. An ensemble of simulations utilizing the old and new schemes shows CESM1's improved response to the 1991 Pinatubo eruption. Most significantly, the new scheme more accurately simulates the temperature response of the stratosphere due to local aerosol heating. Results also indicate that the new scheme decreases the global mean temperature response to the 1991 Pinatubo eruption by half of the observed temperature change, and modelled climate variability precludes statements as to the significance of this change.

  3. Concept Design of a Multiwavelength Aerosol Lidar System With Mitigated Diattenuation Effects and Depolarization-Measurement Capability

    NASA Astrophysics Data System (ADS)

    Comerón, Adolfo; Sicard, Michaël; Vidal, Eric; Barragán, Rubén; Muñoz, Constantino; Rodríguez, Alejandro; Tiana-Alsina, Jordi; Rocadenbosch, Francesc; García-Vizcaíno, David

    2016-06-01

    It is known that the retrieval of aerosol extinction and backscatter coefficients from lidar data acquired through so-called total-power channels - intended to measure the backscattered power irrespective of the polarization - can be adversely affected by varying depolarization effects produced by the aerosol under measurement. This effect can be particularly noticeable in advanced multiwavelength systems, where different wavelengths are separated using a system of dichroic beam splitters, because in general the reflection and transmission coefficients of the beam splitters will be different for fields with polarization parallel or perpendicular to the incidence plane. Here we propose a setup for multiwavelength aerosol lidars alleviating diattenuation effects due to changing depolarization conditions while allowing measure linear depolarization.

  4. Design, assembly, and validation of a nose-only inhalation exposure system for studies of aerosolized viable influenza H5N1 virus in ferrets

    PubMed Central

    2010-01-01

    Background The routes by which humans acquire influenza H5N1 infections have not been fully elucidated. Based on the known biology of influenza viruses, four modes of transmission are most likely in humans: aerosol transmission, ingestion of undercooked contaminated infected poultry, transmission by large droplets and self-inoculation of the nasal mucosa by contaminated hands. In preparation of a study to resolve whether H5N1 viruses are transmissible by aerosol in an animal model that is a surrogate for humans, an inhalation exposure system for studies of aerosolized H5N1 viruses in ferrets was designed, assembled, and validated. Particular attention was paid towards system safety, efficacy of dissemination, the viability of aerosolized virus, and sampling methodology. Results An aerosol generation and delivery system, referred to as a Nose-Only Bioaerosol Exposure System (NBIES), was assembled and function tested. The NBIES passed all safety tests, met expected engineering parameters, required relatively small quantities of material to obtain the desired aerosol concentrations of influenza virus, and delivered doses with high-efficacy. Ferrets withstood a mock exposure trial without signs of stress. Conclusions The NBIES delivers doses of aerosolized influenza viruses with high efficacy, and uses less starting material than other similar designs. Influenza H5N1 and H3N2 viruses remain stable under the conditions used for aerosol generation and sample collection. The NBIES is qualified for studies of aerosolized H5N1 virus. PMID:20573226

  5. Electrodialytic reagent introduction in flow systems.

    PubMed

    Mishra, Santosh K; Dasgupta, Purnendu K

    2010-05-15

    We report on electrodialytic introduction of ionizable molecules of significant size (e.g., 4-(2-pyridyl(azo) resorcinol, PAR)) in capillary scale flow systems. Such reagent introduction can be conducted without volumetric dilution, easily programmed through current control and with excellent mixing characteristics. Electrodialytic transport of large hydrophobic aromatic ions through conventional aromatic ion exchangers is inefficient. Such ions are strongly retained by hydrophobic and pi-pi interactions. An external electric field cannot modulate this retention. We show that the electrodialytic introduction of aromatic dye anions is readily possible through both unmodified cellulose dialysis membranes and through cellulose membranes modified with methacrylate skeleton anion exchangers. The applied electrodialysis current conveniently controls the reagent flux. Although the applied voltage is sufficient to cause electrolytic production of hydrogen and oxygen; the gases are generated outside the flowstream of interest. The present device was constructed with a sub-microliter internal volume. We show capillary scale trace analysis of transition metals. A limit of detection of 0.5 fmol Zn (S/N = 3) is demonstrated with a capillary scale flow injection system with a simple light emitting diode based detector. PMID:20423104

  6. Global Lidar Measurements of Clouds and Aerosols from Space Using the Geoscience Laser Altimeter System (GLAS)

    NASA Technical Reports Server (NTRS)

    Hlavka, Dennis L.; Palm, S. P.; Welton, E. J.; Hart, W. D.; Spinhirne, J. D.; McGill, M.; Mahesh, A.; Starr, David OC. (Technical Monitor)

    2001-01-01

    The Geoscience Laser Altimeter System (GLAS) is scheduled for launch on the ICESat satellite as part of the NASA EOS mission in 2002. GLAS will be used to perform high resolution surface altimetry and will also provide a continuously operating atmospheric lidar to profile clouds, aerosols, and the planetary boundary layer with horizontal and vertical resolution of 175 and 76.8 m, respectively. GLAS is the first active satellite atmospheric profiler to provide global coverage. Data products include direct measurements of the heights of aerosol and cloud layers, and the optical depth of transmissive layers. In this poster we provide an overview of the GLAS atmospheric data products, present a simulated GLAS data set, and show results from the simulated data set using the GLAS data processing algorithm. Optical results from the ER-2 Cloud Physics Lidar (CPL), which uses many of the same processing algorithms as GLAS, show algorithm performance with real atmospheric conditions during the Southern African Regional Science Initiative (SAFARI 2000).

  7. Projected response of East Asian summer monsoon system to future reductions in emissions of anthropogenic aerosols and their precursors

    NASA Astrophysics Data System (ADS)

    Wang, Zhili; Zhang, Hua; Zhang, Xiaoye

    2015-12-01

    The response of the East Asian summer monsoon (EASM) system to reductions in emissions of anthropogenic aerosols and their precursors at the end of the twenty-first century projected by Representative Concentration Pathway 4.5 is studied using an aerosol-climate model with aerosol direct, semi-direct, and indirect effects included. Our results show that the global annual mean aerosol effective radiative forcing at the top of the atmosphere (TOA) is +1.45 W m-2 from 2000 to 2100. The summer mean net all-sky shortwave fluxes averaged over the East Asian monsoon region (EAMR) at the TOA and surface increased by +3.9 and +4.0 W m-2, respectively, due to the reductions of aerosols in 2100 relative to 2000. Changes in radiations affect local thermodynamic and dynamic processes and the hydrological cycle. The summer mean surface temperature and pressure averaged over the EAMR are shown to increase by 1.7 K and decreased by 0.3 hPa, respectively, due to the reduced aerosols. The magnitudes of these changes are larger over land than ocean, causing a marked increase in the contrast of land-sea surface temperature and pressure in the EAMR, thus strengthening the EASM. The summer mean southwest and south winds at 850 hPa are enhanced over eastern and southern China and the surrounding oceans, and the East Asian subtropical jet shifted northward due to the decreases of aerosols. These factors also indicate enhanced EASM circulation, which in turn causes a 10 % increase in summer mean precipitation averaged over the EAMR.

  8. Direct and Semi-direct Effects of Aerosol on the Climate System

    NASA Astrophysics Data System (ADS)

    Mahajan, S.; Evans, K. J.; Hack, J. J.; Truesdale, J.

    2011-12-01

    High-resolution (1x1 degree) global tropospheric aerosol datasets are generated using the atmospheric component of CESM1.0 coupled to an active bulk aerosol model for the 1850's and the period 1960-2000. The interactive aerosol module incorporates surface and elevated emissions of anthropogenic and natural aerosol precursors and oxidants. Experiments performed with the new aerosol datasets in atmosphere only GCM runs reveal that current level of aerosols can cause significant surface cooling and shift precipitation when compared to pre-industrial levels of aerosols. Experiments performed with the atmosphere component coupled to a slab ocean model reveal that aerosols can enhance the land-sea contrast, and cross-equatorial SST gradient leading to enhanced reduction in monsoon and shift in the ITCZ over the tropical Atlantic as compared to the atmosphere only runs. AMIP style experiments with the new aerosol dataset further reveal that aerosols could have had a significant impact on the trends in regional surface temperature and precipitation in the later part of the 20th century.

  9. Optical design and development of the Near Range Lidar system for aerosol investigation at Belsk

    NASA Astrophysics Data System (ADS)

    Posyniak, Michal; Piatruczuk, Aleksander; Szkop, Artur

    2015-04-01

    The development of the lidar system in the Central Geophysics Observatory at Belsk (Poland) is presented. Belsk is an aerosol background site located in a rural area about 50 km south from Warsaw. A new near range (NR) lidar was added to the existing far range (FR) lidar system to enable the acquisition of lidar signals at the distance of a few hundred meters from the device. In the existing design of the FR lidar a 600 mm diameter mirror was used which resultedin anoverlap over 1500 mmaking this device suitable for observations of aerosols in free troposphere and lower stratosphere but not in the Planetary Boundary Layer (PBL).To enable measurements in the PBL the near range detection systemwas designed as a complement of the existing FR lidar. A secondtelescope with a set of detectors was used with the same laser as in the FR system as a light source. The Nd:YAGpulselasergenerates three wavelengths (1064, 532 and 355 nm).Energies of light pulses are about 320 mJ while their repetition rate is 15 Hz. In the optical receiver of the NR lidar a telescope with a 150 mm diameter parabolic mirror with optical fiber (1 mm core diameter) as a field stop was used. Our analysis shows that full overlap of the laser beam and the NR telescope field of view is expected at about 150 m. A polichromator based on dichroic beam splitters and a set of narrow band pass filters were used to separate wavelengths. The design of the NR lidar easily allows to add Raman channels to the system. The acquisition of the analog lidar echoes was done by photomultipliers (at 355 and 532 nm) and the avalanche photodiode (at 1064 nm). 14 bit analog to digital converters coupled with PC computer by USB 2.0 were also used.

  10. Thaw flow control for liquid heat transport systems

    DOEpatents

    Kirpich, Aaron S.

    1989-01-01

    In a liquid metal heat transport system including a source of thaw heat for use in a space reactor power system, the thaw flow throttle or control comprises a fluid passage having forward and reverse flow sections and a partition having a plurality of bleed holes therein to enable fluid flow between the forward and reverse sections. The flow throttle is positioned in the system relatively far from the source of thaw heat.

  11. Constraining Predicted Secondary Organic Aerosol Formation and Processing Using Real-Time Observations of Aging Urban Emissions in an Oxidation Flow Reactor

    NASA Astrophysics Data System (ADS)

    Ortega, A. M.; Palm, B. B.; Hayes, P. L.; Day, D. A.; Cubison, M.; Brune, W. H.; Hu, W.; Graus, M.; Warneke, C.; Gilman, J.; De Gouw, J. A.; Jimenez, J. L.

    2014-12-01

    To investigate atmospheric processing of urban emissions, we deployed an oxidation flow reactor with measurements of size-resolved chemical composition of submicron aerosol during CalNex-LA, a field study investigating air quality and climate change at a receptor site in the Los Angeles Basin. The reactor produces OH concentrations up to 4 orders of magnitude higher than in ambient air, achieving equivalent atmospheric aging of hours to ~2 weeks in 5 minutes of processing. The OH exposure (OHexp) was stepped every 20 min to survey the effects of a range of oxidation exposures on gases and aerosols. This approach is a valuable tool for in-situ evaluation of changes in organic aerosol (OA) concentration and composition due to photochemical processing over a range of ambient atmospheric conditions and composition. Combined with collocated gas-phase measurements of volatile organic compounds, this novel approach enables the comparison of measured SOA to predicted SOA formation from a prescribed set of precursors. Results from CalNex-LA show enhancements of OA and inorganic aerosol from gas-phase precursors. The OA mass enhancement from aging was highest at night and correlated with trimethylbenzene, indicating the importance of relatively short-lived VOC (OH lifetime of ~12 hrs or less) as SOA precursors in the LA Basin. Maximum net SOA production is observed between 3-6 days of aging and decreases at higher exposures. Aging in the reactor shows similar behavior to atmospheric processing; the elemental composition of ambient and reactor measurements follow similar slopes when plotted in a Van Krevelen diagram. Additionally, for air processed in the reactor, oxygen-to-carbon ratios (O/C) of aerosol extended over a larger range compared to ambient aerosol observed in the LA Basin. While reactor aging always increases O/C, often beyond maximum observed ambient levels, a transition from net OA production to destruction occurs at intermediate OHexp, suggesting a transition

  12. Geometrical Optics of Dense Aerosols

    SciTech Connect

    Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

    2013-04-24

    Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________

  13. Observations of Dust Using the NASA Geoscience Laser Altimeter System (GLAS): New New Measurements of Aerosol Vertical Distribution From Space

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth; Spinhirne, James D.; Palm, Steven P.; Hlavka, Dennis; Hart, William

    2003-01-01

    On January 12, 2003 NASA launched the first satellite-based lidar, the Geoscience Laser -Altimeter System (GLAS), onboard the ICESat spacecraft. The GLAS atmospheric measurements introduce a fundamentally new and important tool for understanding the atmosphere and climate. In the past, aerosols have only been studied from space using images gathered by passive sensors. Analysis of this passive data has lead to an improved understanding of aerosol properties, spatial distribution, and their effect on the earth's climate. However, these images do not show the aerosol's vertical distribution. As a result, a key piece of information has been missing. The measurements now obtained by GLAS will provide information on the vertical distribution of aerosols and clouds, and improve our ability to study their transport processes and aerosol-cloud interactions. Here we show an overview of GLAS, provide an update of its current status, and present initial observations of dust profiles. In particular, a strategy of characterizing the height profile of dust plumes over source regions will be presented.

  14. Complex flows in granular and quantum systems

    NASA Astrophysics Data System (ADS)

    Herrera, Mark Richard

    In this thesis we investigate three problems involving complex flows in granular and quantum systems. (a) We first study the dynamics of granular particles in a split-bottom shear cell experiment. We utilize network theory to quantify the dynamics of the granular system at the mesoscopic scale. We find an apparent phase transition in the formation of a giant component of broken links as a function of applied shear. These results are compared to a numerical model where breakages are based on the amount of local stretching in the granular pile. (b) Moving to quantum mechanical systems, we study revival and echo phenomena in systems of anharmonically confined atoms, and find a novel phenomena we call the "pre-revival echo". We study the effect of size and symmetry of the perturbations on the various echoes and revivals, and form a perturbative model to describe the phenomena. We then model the effect of interactions using the Gross-Pitaevskii Equation and study interactions' effect on the revivals. (c) Lastly, we continue to study the effect of interactions on particles in weakly anharmonic traps. We numerically observe a "dynamical localization" phenomena in the presence of both anharmonicity and interactions. States may remain localized or become spread out in the potential depending on the strength and sign of the anharmonicity and interactions. We formulate a model for this phenomena in terms of a classical phase space.

  15. Redox flow cell energy storage systems

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.

    1979-01-01

    NASA-Redox systems are electrochemical storage devices that use two fully soluble Redox couples, anode and cathode fluids, as active electrode materials separated by a highly selective ion exchange membrane. The reactants are contained in large storage tanks and pumped through a stack of Redox flow cells where the electrochemical reactions (reduction and oxidation) take place at porous carbon felt electrodes. A string or stack of these power producing cells is connected in series in a bipolar manner. Redox energy storage systems promise to be inexpensive and possess many features that provide for flexible design, long life, high reliability and minimal operation and maintenance costs. These features include independent sizing of power and storage capacity requirements and inclusion within the cell stack of a cell that monitors the state of charge of the system as a whole, and a rebalance cell which permits continuous correction to be made for minor side reactions that would tend to result in the anode fluid and cathode fluids becoming electrochemically out of balance. These system features are described and discussed.

  16. Mean Flow Augmented Acoustics in Rocket Systems

    NASA Technical Reports Server (NTRS)

    Fischbach, Sean

    2014-01-01

    Combustion instability in solid rocket motors and liquid engines has long been a subject of concern. Many rockets display violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process and gas dynamics. Recent advances in energy based modeling of combustion instabilities require accurate determination of acoustic frequencies and mode shapes. Of particular interest is the acoustic mean flow interactions within the converging section of a rocket nozzle, where gradients of pressure, density, and velocity become large. The expulsion of unsteady energy through the nozzle of a rocket is identified as the predominate source of acoustic damping for most rocket systems. Recently, an approach to address nozzle damping with mean flow effects was implemented by French [1]. This new approach extends the work originated by Sigman and Zinn [2] by solving the acoustic velocity potential equation (AVPE) formulated by perturbing the Euler equations [3]. The present study aims to implement the French model within the COMSOL Multiphysiscs framework and analyzes one of the author's presented test cases.

  17. Stochastic uncertainty analysis for unconfined flow systems

    USGS Publications Warehouse

    Liu, Gaisheng; Zhang, Dongxiao; Lu, Zhiming

    2006-01-01

    A new stochastic approach proposed by Zhang and Lu (2004), called the Karhunen-Loeve decomposition-based moment equation (KLME), has been extended to solving nonlinear, unconfined flow problems in randomly heterogeneous aquifers. This approach is on the basis of an innovative combination of Karhunen-Loeve decomposition, polynomial expansion, and perturbation methods. The random log-transformed hydraulic conductivity field (InKS) is first expanded into a series in terms of orthogonal Gaussian standard random variables with their coefficients obtained as the eigenvalues and eigenfunctions of the covariance function of InKS- Next, head h is decomposed as a perturbation expansion series ??A(m), where A(m) represents the mth-order head term with respect to the standard deviation of InKS. Then A(m) is further expanded into a polynomial series of m products of orthogonal Gaussian standard random variables whose coefficients Ai1,i2(m)...,im are deterministic and solved sequentially from low to high expansion orders using MODFLOW-2000. Finally, the statistics of head and flux are computed using simple algebraic operations on Ai1,i2(m)...,im. A series of numerical test results in 2-D and 3-D unconfined flow systems indicated that the KLME approach is effective in estimating the mean and (co)variance of both heads and fluxes and requires much less computational effort as compared to the traditional Monte Carlo simulation technique. Copyright 2006 by the American Geophysical Union.

  18. Mean Flow Augmented Acoustics in Rocket Systems

    NASA Technical Reports Server (NTRS)

    Fischbach, Sean R.

    2014-01-01

    Oscillatory motion in solid rocket motors and liquid engines has long been a subject of concern. Many rockets display violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process and gas dynamics. The customary approach to modeling acoustic waves inside a rocket chamber is to apply the classical inhomogeneous wave equation to the combustion gas. The assumption of a linear, non-dissipative wave in a quiescent fluid remains valid while the acoustic amplitudes are small and local gas velocities stay below Mach 0.2. The converging section of a rocket nozzle, where gradients in pressure, density, and velocity become large, is a notable region where this approach is not applicable. The expulsion of unsteady energy through the nozzle of a rocket is identified as the predominate source of acoustic damping for most rocket systems. An accurate model of the acoustic behavior within this region where acoustic modes are influenced by the presence of a steady mean flow is required for reliable stability predictions. Recently, an approach to address nozzle damping with mean flow effects was implemented by French [1]. This new approach extends the work originated by Sigman and Zinn [2] by solving the acoustic velocity potential equation (AVPE) formulated by perturbing the Euler equations [3]. The acoustic velocity potential (psi) describing the acoustic wave motion in the presence of an inhomogeneous steady high-speed flow is defined by, (del squared)(psi) - (lambda/c)(exp 2)(psi) - M(dot)[M(dot)(del)(del(psi))] - 2(lambda(M/c) + (M(dot)del(M))(dot)del(psi)-2(lambda)(psi)[M(dot)del(1/c)]=0 (1) with M as the Mach vector, c as the speed of sound, and lambda as the complex eigenvalue. French apply the finite volume method to solve the steady flow field within the combustion chamber and nozzle with inviscid walls. The complex eigenvalues and eigenvector are determined with the use of the ARPACK eigensolver. The

  19. Sample introduction system for a flow cytometer

    DOEpatents

    Engh, G. van den

    1997-02-11

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning, HPLC tubing and fittings may be used in a manner which facilitates removing of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it. 3 figs.

  20. Sample introduction system for a flow cytometer

    DOEpatents

    Van den Engh, Ger

    1997-01-01

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning, HPLC tubing and fittings may be used in a manner which facilitates removing of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it.

  1. Investigating Biofilm Recalcitrance In Pipe Flow Systems

    NASA Astrophysics Data System (ADS)

    Aggarwal, S.; Stewart, P. S.; Hozalski, R. M.

    2015-12-01

    It is challenging to remove biofilms from pipe walls owing to their recalcitrant nature. Several physiological explanations resulting from the community existence of microbes have been offered to explain the recalcitrant nature of biofilms. Herein a biophysical aspect of biofilm recalcitrance is being reported. While optimal efficiency argument suggests that bacterial biofilms would be just strong enough to withstand the surrounding shear forces, our experimental findings reveal the biofilms to be at least 330 to 55000 times stronger. Additionally, Monte-Carlo simulations for biofilm detachment in drinking water systems were performed, which show that the existing flow velocities are insufficient for significant biofilm removal and warrant alternative detachment strategies. This emphasizes the importance of considering strategies for biofilm weakening (and subsequent detachment) in conjunction with or as an alternative to bacterial inactivation.

  2. Evaluation of an air-filtration system for preventing aerosol transmission of Porcine reproductive and respiratory syndrome virus

    PubMed Central

    2005-01-01

    Abstract The purpose of this study was to evaluate the ability of a commercial air-filtration system to reduce aerosol transmission of Porcine reproductive and respiratory syndrome virus (PRRSV). The system consisted of a pre-filter and 2 filters with EU8 and EU13 ratings. In each of 4 trials, 5 PRRSV-infected donor pigs and 1 naïve recipient pig (each 25 kg) were housed in opposing chambers connected by a 1.3-m-long duct. The system filtered air entering 1 recipient-pig chamber (filtered facility) from the donor- chamber but not a 2nd recipient-pig chamber (nonfiltered facility). The donor pigs had been experimentally infected with PRRSV MN-184, an isolate previously documented to be shed at a high frequency in contagious aerosols. On days 3 to 7 after infection of the donors, the 2 groups were housed in their respective chambers for 6 h and then in separate facilities, where samples were collected for testing by polymerase chain reaction and enzyme-linked immunosorbent assay over 14 d. Aerosol transmission was observed in 6 of the 20 replicates in the nonfiltered facility, whereas all pigs remained PRRSV-negative in the filtered facility; the difference was significant at P < 0.01. Thus, under the conditions of this study, the air-filtration system evaluated appeared to be highly effective at reducing aerosol transmission of PRRSV. PMID:16479728

  3. Design of an Unattended Environmental Aerosol Sampling and Analysis System for Gaseous Centrifuge Enrichment Plants

    SciTech Connect

    Anheier, Norman C.; Munley, John T.; Alexander, M. L.

    2011-07-19

    the in-facility misuse detection devices. Onsite environmental sample collection offers the ability to collect fleeting uranium hexafluoride emissions before they are lost to the ventilation system or before they disperse throughout the facility, to become deposited onto surfaces that are contaminated with background and historical production material. Onsite aerosol sample collection, combined with enrichment analysis, provides the unique ability to quickly detect stepwise enrichment level changes within the facility, leading to a significant strengthening of facility misuse deterence. We report in this paper our study of several GCEP environmental sample release scenarios and simulation results of a newly designed aerosol collection and particle capture system that is fully integrated with the Laser Ablation, Absorbance Ratio Spectrometry (LAARS) uranium particle enrichment analysis instrument that was developed at the Pacific Northwest National Laboratory.

  4. Mentat: An object-oriented macro data flow system

    NASA Technical Reports Server (NTRS)

    Grimshaw, Andrew S.; Liu, Jane W. S.

    1988-01-01

    Mentat, an object-oriented macro data flow system designed to facilitate parallelism in distributed systems, is presented. The macro data flow model is a model of computation similar to the data flow model with two principal differences: the computational complexity of the actors is much greater than in traditional data flow systems, and there are persistent actors that maintain state information between executions. Mentat is a system that combines the object-oriented programming paradigm and the macro data flow model of computation. Mentat programs use a dynamic structure called a future list to represent the future of computations.

  5. Direct and semi-direct aerosol radiative effect on the Mediterranean climate variability using a coupled regional climate system model

    NASA Astrophysics Data System (ADS)

    Nabat, Pierre; Somot, Samuel; Mallet, Marc; Sevault, Florence; Chiacchio, Marc; Wild, Martin

    2015-02-01

    A fully coupled regional climate system model (CNRM-RCSM4) has been used over the Mediterranean region to investigate the direct and semi-direct effects of aerosols, but also their role in the radiation-atmosphere-ocean interactions through multi-annual ensemble simulations (2003-2009) with and without aerosols and ocean-atmosphere coupling. Aerosols have been taken into account in CNRM-RCSM4 through realistic interannual monthly AOD climatologies. An evaluation of the model has been achieved, against various observations for meteorological parameters, and has shown the ability of CNRM-RCSM4 to reproduce the main patterns of the Mediterranean climate despite some biases in sea surface temperature (SST), radiation and cloud cover. The results concerning the aerosol radiative effects show a negative surface forcing on average because of the absorption and scattering of the incident radiation. The SW surface direct effect is on average -20.9 Wm-2 over the Mediterranean Sea, -14.7 Wm-2 over Europe and -19.7 Wm-2 over northern Africa. The LW surface direct effect is weaker as only dust aerosols contribute (+4.8 Wm-2 over northern Africa). This direct effect is partly counterbalanced by a positive semi-direct radiative effect over the Mediterranean Sea (+5.7 Wm-2 on average) and Europe (+5.0 Wm-2) due to changes in cloud cover and atmospheric circulation. The total aerosol effect is consequently negative at the surface and responsible for a decrease in land (on average -0.4 °C over Europe, and -0.5 °C over northern Africa) and sea surface temperature (on average -0.5 °C for the Mediterranean SST). In addition, the latent heat loss is shown to be weaker (-11.0 Wm-2) in the presence of aerosols, resulting in a decrease in specific humidity in the lower troposphere, and a reduction in cloud cover and precipitation. Simulations also indicate that dust aerosols warm the troposphere by absorbing solar radiation, and prevent radiation from reaching the surface, thus

  6. The Cloud-Aerosol Transport System (CATS): a technology demonstration on the International Space Station

    NASA Astrophysics Data System (ADS)

    McGill, Matthew J.; Yorks, John E.; Scott, V. S.; Kupchock, Andrew W.; Selmer, Patrick A.

    2015-09-01

    The Cloud-Aerosol Transport System (CATS) is a multi-wavelength lidar instrument developed to enhance Earth Science remote sensing capabilities from the International Space Station. The CATS project was chartered to be an experiment in all senses: science, technology, and management. As a low-cost project following a strict build-to-cost/ build-to-schedule philosophy, CATS is following a new management approach while also serving as a technology demonstration for future NASA missions. This presentation will highlight the CATS instrument and science objectives with emphasis on how the ISS platform enables the specific objectives of the payload. The development process used for CATS and a look at data being produced by the instrument will also be presented.

  7. Laser cross-flow gas system

    DOEpatents

    Duncan, David B.

    1992-01-01

    A method and laser apparatus are disclosed which provide for a cross-flow of gas near one end of a laser discharge tube. The cross-flow of gas causes a concentration gradient which affects diffusion of contaminants in the discharge tube towards the cross-flow of the gas, which contaminants are then withdrawn from the discharge tube.

  8. Recent advances in the development of a novel aerosol sorting and deposition system for bio-threat sensing applications

    NASA Astrophysics Data System (ADS)

    Pletcher, Timothy; McGinn, Joseph; Keller, David; Huston, Alan; Eversole, Jay; Sivaprakasum, Vasanthi

    2007-10-01

    Sarnoff Corporation and the Naval Research Laboratory, through support of the U.S. Department of Homeland Security, are developing an automated, high throughput bio-aerosol physical enrichment system designed for use as part of a biological-threat protection system. The Biological Aerosol-Capture-Enrichment (BioACE) system is a bio-aerosol collection system that combines three unique technologies to create physically enriched aerosol samples that can be subsequently interrogated by any number of bio-threat detection systems for the presence of threat agents. An air-to-air concentrator uses an inertial separation technique to highly concentrate an aerosol sample presented to a dual wavelength ultra-violet laser induced fluorescence (UVLIF) optical trigger used to discriminate potential threat particles from non-threat particles conveyed in a collimated particle stream. This particle classification information is used to trigger an electrostatic deposition mechanism to deposit only those particles determined to be potential bio-threats onto a stainless steel substrate. Non-threat particles are discarded with the exiting airflow. The goal for the most recent development effort has been the integration and optimization of these technologies into a unit capable of producing highly enriched particulate samples from ambient air containing variable background aerosol loading and type. Several key technical and engineering challenges were overcome during the course of this development including a unique solution for compensating particle velocity dispersion within the airflow, development of a real-time signal acquisition and detection algorithm for determining material type on a particle by particle basis at rates greater than 2000 particles per second, and the introduction of a robust method for transferring deposited particulate into a 50ul wet sample suitable for most advanced bio-detection techniques. This paper will briefly describe the overall system architecture and

  9. Fate of inhaled monoclonal antibodies after the deposition of aerosolized particles in the respiratory system.

    PubMed

    Guilleminault, L; Azzopardi, N; Arnoult, C; Sobilo, J; Hervé, V; Montharu, J; Guillon, A; Andres, C; Herault, O; Le Pape, A; Diot, P; Lemarié, E; Paintaud, G; Gouilleux-Gruart, V; Heuzé-Vourc'h, N

    2014-12-28

    Monoclonal antibodies (mAbs) are usually delivered systemically, but only a small proportion of the drug reaches the lung after intravenous injection. The inhalation route is an attractive alternative for the local delivery of mAbs to treat lung diseases, potentially improving tissue concentration and exposure to the drug while limiting passage into the bloodstream and adverse effects. Several studies have shown that the delivery of mAbs or mAb-derived biopharmaceuticals via the airways is feasible and efficient, but little is known about the fate of inhaled mAbs after the deposition of aerosolized particles in the respiratory system. We used cetuximab, an anti-EGFR antibody, as our study model and showed that, after its delivery via the airways, this mAb accumulated rapidly in normal and cancerous tissues in the lung, at concentrations twice those achieved after intravenous delivery, for early time points. The spatial distribution of cetuximab within the tumor was heterogeneous, as reported after i.v. injection. Pharmacokinetic (PK) analyses were carried out in both mice and macaques and showed aerosolized cetuximab bioavailability to be lower and elimination times shorter in macaques than in mice. Using transgenic mice, we showed that FcRn, a key receptor involved in mAb distribution and PK, was likely to make a greater contribution to cetuximab recycling than to the transcytosis of this mAb in the airways. Our results indicate that the inhalation route is potentially useful for the treatment of both acute and chronic lung diseases, to boost and ensure the sustained accumulation of mAbs within the lungs, while limiting their passage into the bloodstream. PMID:25451545

  10. Culture-Independent Analysis of Aerosol Microbiology in a Metropolitan Subway System

    PubMed Central

    Robertson, Charles E.; Baumgartner, Laura K.; Harris, J. Kirk; Peterson, Kristen L.; Stevens, Mark J.; Frank, Daniel N.

    2013-01-01

    The goal of this study was to determine the composition and diversity of microorganisms associated with bioaerosols in a heavily trafficked metropolitan subway environment. We collected bioaerosols by fluid impingement on several New York City subway platforms and associated sites in three sampling sessions over a 1.5-year period. The types and quantities of aerosolized microorganisms were determined by culture-independent phylogenetic analysis of small-subunit rRNA gene sequences by using both Sanger (universal) and pyrosequencing (bacterial) technologies. Overall, the subway bacterial composition was relatively simple; only 26 taxonomic families made up ∼75% of the sequences determined. The microbiology was more or less similar throughout the system and with time and was most similar to outdoor air, consistent with highly efficient air mixing in the system. Identifiable bacterial sequences indicated that the subway aerosol assemblage was composed of a mixture of genera and species characteristic of soil, environmental water, and human skin commensal bacteria. Eukaryotic diversity was mainly fungal, dominated by organisms of types associated with wood rot. Human skin bacterial species (at 99% rRNA sequence identity) included the Staphylococcus spp. Staphylococcus epidermidis (the most abundant and prevalent commensal of the human integument), S. hominis, S. cohnii, S. caprae, and S. haemolyticus, all well-documented human commensal bacteria. We encountered no organisms of public health concern. This study is the most extensive culture-independent survey of subway microbiota so far and puts in place pre-event information required for any bioterrorism surveillance activities or monitoring of the microbiological impact of recent subway flooding events. PMID:23542619

  11. Evaluating the capabilities of aerosol-to-liquid particle extraction system (ALPXS)/ICP-MS for monitoring trace metals in indoor air.

    PubMed

    Jayawardene, Innocent; Rasmussen, Pat E; Chenier, Marc; Gardner, H David

    2014-09-01

    This study investigates the application of the Aerosol-to-Liquid Particle Extraction System (ALPXS), which uses wet electrostatic precipitation to collect airborne particles, for multi-element indoor stationary monitoring. Optimum conditions are determined for capturing airborne particles for metal determination by inductively coupled plasma-mass spectrometry (ICP-MS), for measuring field blanks, and for calculating limits of detection (LOD) and quantification (LOQ). Due to the relatively high flow rate (300 L min(-1)), a sampling duration of 1 hr to 2 hr was adequate to capture airborne particle-bound metals under the investigated experimental conditions. The performance of the ALPXS during a building renovation demonstrated signal-to-noise ratios appropriate for sampling airborne particles in environments with elevated metal concentrations, such as workplace settings. The ALPXS shows promise as a research tool for providing useful information on short-term variations (transient signals) and for trapping particles into aqueous solutions where needed for subsequent characterization. As the ALPXS does not provide size-specific samples, and its efficiency at different flow rates has yet to be quantified, the ALPXS would not replace standard filter-based protocols accepted for regulatory applications (e.g., exposure measurements), but rather would provide additional information if used in conjunction with filter based methods. Implications: This study investigates the capability of the Aerosol-to-Liquid Particle Extraction System (ALPXS) for stationary sampling of airborne metals in indoor workplace environments, with subsequent analysis by ICP-MS. The high flow rate (300 L/min) permits a short sampling duration (< 2 hr). Results indicated that the ALPXS was capable of monitoring short-term changes in metal emissions during a renovation activity. This portable instrument may prove to be advantageous in occupational settings as a qualitative indicator of elevated

  12. Development and Characterization of a Thermodenuder for Aerosol Volatility Measurements

    SciTech Connect

    Dr. Timothy Onasch

    2009-09-09

    due to coatings on soot particles). The successfully completed Phase I project included construction of a prototype design for the TD with detailed physical modeling, testing with laboratory and ambient aerosol particles, and the initiation of a detailed microphysical model of the aerosol particles passing through the TD to extract vapor pressure distributions. The objective of the microphysical model is to derive vapor pressure distributions (i.e. vapor pressure ranges, including single chemical compounds, mixtures of known compounds, and complex ‘real-world’ aerosols, such as SOA, and soot particles with absorbing and nonabsorbing coatings) from TD measurements of changes in particle size, mass, and chemical composition for known TD temperatures and flow rates (i.e. residence times). The proposed Phase II project was designed to optimize several TD systems for different instrument applications and to combine the hardware and modeling into a robust package for commercial sales.

  13. Design and testing of Electrostatic Aerosol in Vitro Exposure System (EAVES): an alternative exposure system for particles.

    PubMed

    de Bruijne, K; Ebersviller, S; Sexton, K G; Lake, S; Leith, D; Goodman, R; Jetters, J; Walters, G W; Doyle-Eisele, M; Woodside, R; Jeffries, H E; Jaspers, I

    2009-02-01

    Conventional in vitro exposure methods for cultured human lung cells rely on prior suspension of particles in a liquid medium; these have limitations for exposure intensity and may modify the particle composition. Here electrostatic precipitation was used as an effective method for such in vitro exposures. An obsolete electrostatic aerosol sampler was modified to provide a viable environment within the deposition field for human lung cells grown on membranous support. Particle deposition and particle-induced toxicological effects for a variety of particles including standardized polystyrene latex spheres (PSL) and diesel exhaust emission particle mixtures are reported. The Electrostatic Aerosol in Vitro Exposure System (EAVES) efficiently deposited particles from an air stream directly onto cells. Cells exposed to the electric field of the EAVES in clean air or in the presence of charged PSL spheres exhibited minimal cytotoxicity, and their release of inflammatory cytokines was indistinguishable from that of the controls. For the responses tested here, there are no significant adverse effects caused neither by the electric field alone nor by the mildly charged particles. Exposure to diesel exhaust emissions using the EAVES system induced a threefold increase in cytokines and cytotoxicity as compared to the control. Taken together, these data show that the EAVES can be used to expose human lung cells directly to particles without prior collection in media, thereby providing an efficient and effective alternative to the more conventional particle in vitro exposure methods. PMID:18800273

  14. Impact of Aerosol Processing on Orographic Clouds

    NASA Astrophysics Data System (ADS)

    Pousse-Nottelmann, Sara; Zubler, Elias M.; Lohmann, Ulrike

    2010-05-01

    . [6]. Our investigation regarding the influence of aerosol processing will focus on the regional scale using a cloud-system resolving model with a much higher resolution. Emphasis will be placed on orographic mixed-phase precipitation. Different two-dimensional simulations of idealized orographic clouds will be conducted to estimate the effect of aerosol processing on orographic cloud formation and precipitation. Here, cloud lifetime, location and extent as well as the cloud type will be of particular interest. In a supplementary study, the new parameterization will be compared to observations of total and interstitial aerosol concentrations and size distribution at the remote high alpine research station Jungfraujoch in Switzerland. In addition, our simulations will be compared to recent simulations of aerosol processing in warm, mixed-phase and cold clouds, which have been carried out at the location of Jungfraujoch station [5]. References: [1] Pruppacher & Jaenicke (1995), The processing of water vapor and aerosols by atmospheric clouds, a global estimate, Atmos. Res., 38, 283295. [2] Seifert & Beheng (2006), A two-moment microphysics parameterization for mixed-phase clouds. Part 1: Model description, Meteorol. Atmos. Phys., 92, 4566. [3] Vignati et al. (2004), An efficient size-resolved aerosol microphysics module for large-scale transport models, J. Geophys. Res., 109, D22202 [4] Muhlbauer & Lohmann (2008), Sensitivity studies of the role of aerosols in warm-phase orographic precipitation in different flow regimes, J. Atmos. Sci., 65, 25222542. [5] Hoose et al. (2008), Aerosol processing in mixed-phase clouds in ECHAM5HAM: Model description and comparison to observations, J. Geophys. Res., 113, D071210. [6] Hoose et al. (2008), Global simulations of aerosol processing in clouds, Atmos. Chem. Phys., 8, 69396963.

  15. Aerosols, Clouds, and Precipitation as Scale Interactions in the Climate System and Controls on Climate Change

    NASA Astrophysics Data System (ADS)

    Donner, Leo

    Clouds are major regulators of atmospheric energy flows. Their character depends on atmospheric composition, dynamics, and thermodynamic state. Clouds can assume organized structures whose scales are planetary, while processes important for determining basic properties occur on the scale of microns. The range of processes, scales, and interactions among them has precluded the development of concise theories for the role of clouds in climate, and limitations in modeling clouds in complex climate models remain among the key uncertainties in understanding and projecting climate change. The distribution function of vertical velocities (updraft speeds) in clouds is an important control on climate forcing by clouds and possibly a strong correlate with climate sensitivity. (Climate forcing refers to the change in Earth's energy balance as atmospheric composition changes, in particular, due to human activity. Climate sensitivity is defined here as the equilibrium change in globally averaged annual surface temperature as a result of doubled carbon dioxide.) Vertical velocities are central because they determine the thermodynamic environment governing phase changes of water, with both equilibrium and non-equilibrium phenomena important. The spatial and temporal spectra of relevant vertical velocities includes scales both numerically resolved by climate models and below their resolution limit. The latter implies a requirement to parameterize these smaller scale motions in models. The scale dependence of vertical velocities and emerging observational constraints on their distribution provide new opportunities for representing aerosols, clouds, and precipitation in climate models. Success in doing so could provide important breakthroughs in understanding both climate forcing and sensitivity.

  16. System for measuring multiphase flow using multiple pressure differentials

    DOEpatents

    Fincke, James R.

    2003-01-01

    An improved method and system for measuring a multi-phase flow in a pressure flow meter. An extended throat venturi is used and pressure of the multi-phase flow is measured at three or more positions in the venturi, which define two or more pressure differentials in the flow conduit. The differential pressures are then used to calculate the mass flow of the gas phase, the total mass flow, and the liquid phase. The system for determining the mass flow of the high void fraction fluid flow and the gas flow includes taking into account a pressure drop experienced by the gas phase due to work performed by the gas phase in accelerating the liquid phase.

  17. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols.

    PubMed

    Higdon, N S; Browell, E V; Ponsardin, P; Grossmann, B E; Butler, C F; Chyba, T H; Mayo, M N; Allen, R J; Heuser, A W; Grant, W B; Ismail, S; Mayor, S D; Carter, A F

    1994-09-20

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H(2)O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and > 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H(2)O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H(2)O absorption-line parameters were perfo med to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H(2)O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H(2)O radiosondes. The H(2)O distributions measured with the DIAL system differed by ≤ 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions. PMID:20941181

  18. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols

    NASA Technical Reports Server (NTRS)

    Carter, Arlen F.; Allen, Robert J.; Mayo, M. Neale; Butler, Carolyn F.; Grossman, Benoist E.; Ismail, Syed; Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Mayor, Shane D.; Ponsardin, Patrick; Hueser, Alene W.

    1994-01-01

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H2O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and greater than 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H2O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H2O absorption-line parameters were performed to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H2O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H2O radiosondes. The H2O distributions measured with the DIAL system differed by less than 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  19. Atmospheric Aerosols

    NASA Technical Reports Server (NTRS)

    Pueschel, R. F.; Lawless, James G. (Technical Monitor)

    1994-01-01

    Aerosols, defined as particles and droplets suspended in air, are always present in the atmosphere. They are part of the earth-atmosphere climate system, because they interact with both incoming solar and outgoing terrestrial radiation. They do this directly through scattering and absorption, and indirectly through effects on clouds. Submicrometer aerosols usually predominate in terms of number of particles per unit volume of air. They have dimensions close to the wavelengths of visible light, and thus scatter radiation from the sun very effectively. They are produced in the atmosphere by chemical reactions of sulfur-, nitrogen- and carbon-containing gases of both natural and anthropogenic origins. Light absorption is dominated by particles containing elemental carbon (soot), produced by incomplete combustion of fossil fuels and by biomass burning. Light-scattering dominates globally, although absorption can be significant at high latitudes, particularly over highly reflective snow- or ice-covered surfaces. Other aerosol substances that may be locally important are those from volcanic eruptions, wildfires and windblown dust.

  20. DEVELOPMENT OF AN RH -DENUDED MIE ACTIVE SAMPLING SYSTEM AND TARGETED AEROSOL CALIBRATION

    EPA Science Inventory

    The MIE pDR 1200 nephelometer provides time resolved aerosol concentrations during personal and fixed-site sampling. Active (pumped) operation allows defining an upper PM2.5 particle size, however, this dramatically increases the aerosol mass passing through the phot...

  1. MODELING THE FORMATION OF SECONDARY ORGANIC AEROSOL WITHIN A COMPREHENSIVE AIR QUALITY MODEL SYSTEM

    EPA Science Inventory

    The aerosol component of the CMAQ model is designed to be an efficient and economical depiction of aerosol dynamics in the atmosphere. The approach taken represents the particle size distribution as the superposition of three lognormal subdistributions, called modes. The proces...

  2. Evaluations of Thin Cirrus Contamination and Screening in Ground Aerosol Observations Using Collocated Lidar Systems

    NASA Technical Reports Server (NTRS)

    Huang, Jingfeng; Hsu, N. Christina; Tsay, Si-Chee; Holben, Brent N.; Welton, Ellsworth J.; Smirnov, Alexander; Jeong, Myeong-Jae; Hansell, Richard A.; Berkoff, Timothy A.

    2012-01-01

    Cirrus clouds, particularly sub visual high thin cirrus with low optical thickness, are difficult to be screened in operational aerosol retrieval algorithms. Collocated aerosol and cirrus observations from ground measurements, such as the Aerosol Robotic Network (AERONET) and the Micro-Pulse Lidar Network (MPLNET), provide us with an unprecedented opportunity to examine the susceptibility of operational aerosol products to thin cirrus contamination. Quality assured aerosol optical thickness (AOT) measurements were also tested against the CALIPSO vertical feature mask (VFM) and the MODIS-derived thin cirrus screening parameters for the purpose of evaluating thin cirrus contamination. Key results of this study include: (1) Quantitative evaluations of data uncertainties in AERONET AOT retrievals are conducted. Although AERONET cirrus screening schemes are successful in removing most cirrus contamination, strong residuals displaying strong spatial and seasonal variability still exist, particularly over thin cirrus prevalent regions during cirrus peak seasons, (2) Challenges in matching up different data for analysis are highlighted and corresponding solutions proposed, and (3) Estimation of the relative contributions from cirrus contamination to aerosol retrievals are discussed. The results are valuable for better understanding and further improving ground aerosol measurements that are critical for aerosol-related climate research.

  3. Other medications for aerosol delivery.

    PubMed

    Rubin, Bruce K

    2006-01-01

    Although aerosol therapy is most commonly used to treat asthma and COPD, there are a large number of aerosol medications now used or in development for other diseases. Mucoactive agents have long been available by aerosol, but now we have truly effective drugs to improve effective airway clearance including dornase alfa, hyperosmolar saline, and aerosol surfactant. Inhaled antibiotics are available for the treatment of cystic fibrosis, bronchiectasis and other chronic airway infections. With the development of devices that can target aerosol to the deep lung, the opportunity to deliver medications systemically by the aerosol route has become a reality. Insulin, recently approved in the US as aerosol therapy, and other peptides are systemically absorbed from the distal airway and alveolus. Aerosol gene transfer therapy to correct abnormalities associated with cystic fibrosis, primary ciliary dyskinesia and other airway diseases also holds great potential. PMID:16798603

  4. HOUSTON AEROSOL CHARACTERIZATION STUDY

    EPA Science Inventory

    An intensive field study of ambient aerosols was conducted in Houston between September 14 and October 14, 1978. Measurements at 12 sites were made using (1) two relocatable monitoring systems instrumented for aerosol and gaseous pollutants, (2) a network of high volume samplers ...

  5. Application of a global nonhydrostatic model with a stretched-grid system to regional aerosol simulations around Japan

    NASA Astrophysics Data System (ADS)

    Goto, D.; Dai, T.; Satoh, M.; Tomita, H.; Uchida, J.; Misawa, S.; Inoue, T.; Tsuruta, H.; Ueda, K.; Ng, C. F. S.; Takami, A.; Sugimoto, N.; Shimizu, A.; Ohara, T.; Nakajima, T.

    2015-02-01

    An aerosol-coupled global nonhydrostatic model with a stretched-grid system has been developed. Circulations over the global and target domains are simulated with a single model, which includes fine meshes covering the target region to calculate meso-scale circulations. The stretched global model involves lower computational costs to simulate atmospheric aerosols with fine horizontal resolutions compared with a global uniform nonhydrostatic model, whereas it may require higher computational costs compared with the general regional models, because the stretched-grid system calculates inside and outside the target domain. As opposed to general regional models, the stretched-grid system requires neither a nesting technique nor lateral boundary conditions. In this study, we developed a new-type regional model for the simulation of aerosols over Japan, especially in the Kanto areas surrounding Tokyo, with a maximum horizontal resolution of approximately 10 km. This model usually reproduces temporal variations and their averages of the observed weather around Japan. This model generally reproduces monthly mean distributions of the observed sulfate and SO2 over East Asia, with high correlations (R > 0.6), but the underestimation of the simulated concentrations by 40% (sulfate) and 50% (SO2). Their underestimation of the simulated sulfate and SO2 concentrations over East Asia are strongly affected by their underestimation in China and possibly by the uncertainty of the simulated precipitation around Japan. In the Kanto area, this model succeeds in simulating the wind patterns and the diurnal transitions around the center of the Kanto area, although it is inadequate to simulate the wind patterns and the diurnal transitions at some sites located at the edge of the Kanto area and surrounded on three sides by mountains, e.g., Maebashi, mainly due to the insufficient horizontal resolution. This model also generally reproduces both diurnal and synoptic variations of the observed

  6. Validation of reactive gases and aerosols in the MACC global analysis and forecast system

    NASA Astrophysics Data System (ADS)

    Eskes, H.; Huijnen, V.; Arola, A.; Benedictow, A.; Blechschmidt, A.-M.; Botek, E.; Boucher, O.; Bouarar, I.; Chabrillat, S.; Cuevas, E.; Engelen, R.; Flentje, H.; Gaudel, A.; Griesfeller, J.; Jones, L.; Kapsomenakis, J.; Katragkou, E.; Kinne, S.; Langerock, B.; Razinger, M.; Richter, A.; Schultz, M.; Schulz, M.; Sudarchikova, N.; Thouret, V.; Vrekoussis, M.; Wagner, A.; Zerefos, C.

    2015-11-01

    The European MACC (Monitoring Atmospheric Composition and Climate) project is preparing the operational Copernicus Atmosphere Monitoring Service (CAMS), one of the services of the European Copernicus Programme on Earth observation and environmental services. MACC uses data assimilation to combine in situ and remote sensing observations with global and regional models of atmospheric reactive gases, aerosols, and greenhouse gases, and is based on the Integrated Forecasting System of the European Centre for Medium-Range Weather Forecasts (ECMWF). The global component of the MACC service has a dedicated validation activity to document the quality of the atmospheric composition products. In this paper we discuss the approach to validation that has been developed over the past 3 years. Topics discussed are the validation requirements, the operational aspects, the measurement data sets used, the structure of the validation reports, the models and assimilation systems validated, the procedure to introduce new upgrades, and the scoring methods. One specific target of the MACC system concerns forecasting special events with high-pollution concentrations. Such events receive extra attention in the validation process. Finally, a summary is provided of the results from the validation of the latest set of daily global analysis and forecast products from the MACC system reported in November 2014.

  7. Deployable Plume and Aerosol Release Prediction and Tracking System. Nuclear Non-Proliferation Task 1. Final Report

    SciTech Connect

    Kleppe, John; Norris, William; Etezadi, Mehdi

    2006-07-19

    This contract was awarded in response to a proposal in which a deployable plume and aerosol release prediction and tracking system would be designed, fabricated, and tested. The system would gather real time atmospheric data and input it into a real time atmospheric model that could be used for plume predition and tracking. The system would be able to be quickly deployed by aircraft to points of interest or positioned for deployment by vehicles. The system would provide three dimensional (u, v, and w) wind vector data, inversion height measurements, surface wind information, classical weather station data, and solar radiation. The on-board real time computer model would provide the prediction of the behavior of plumes and released aerosols.

  8. Measurements of the Vertical Structure of Aerosols and Clouds Over the Ocean Using Micro-Pulse LIDAR Systems

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Spinhirne, James D.; Campbell, James R.; Berkoff, Timothy A.; Bates, David; Starr, David OC. (Technical Monitor)

    2001-01-01

    The determination of the vertical distribution of aerosols and clouds over the ocean is needed for accurate retrievals of ocean color from satellites observations. The presence of absorbing aerosol layers, especially at altitudes above the boundary layer, has been shown to influence the calculation of ocean color. Also, satellite data must be correctly screened for the presence of clouds, particularly cirrus, in order to measure ocean color. One instrument capable of providing this information is a lidar, which uses pulses of laser light to profile the vertical distribution of aerosol and cloud layers in the atmosphere. However, lidar systems prior to the 1990s were large, expensive, and not eye-safe which made them unsuitable for cruise deployments. During the 1990s the first small, autonomous, and eye-safe lidar system became available: the micro-pulse lidar, or MPL. The MPL is a compact and eye-safe lidar system capable of determining the range of aerosols and clouds by firing a short pulse of laser light (523 nm) and measuring the time-of-flight from pulse transmission to reception of a returned signal. The returned signal is a function of time, converted into range using the speed of light, and is proportional to the amount of light backscattered by atmospheric molecules (Rayleigh scattering), aerosols, and clouds. The MPL achieves ANSI eye-safe standards by sending laser pulses at low energy (micro-J) and expanding the beam to 20.32 cm in diameter. A fast pulse-repetition-frequency (2500 Hz) is used to achieve a good signal-to-noise, despite the low output energy. The MPL has a small field-of-view (< 100 micro-rad) and signals received with the instrument do not contain multiple scattering effects. The MPL has been used successfully at a number of long-term sites and also in several field experiments around the world.

  9. Paper-based flow fractionation system for preconcentration and field-flow fractionation.

    NASA Astrophysics Data System (ADS)

    Hong, Seokbin; Kwak, Rhokyun; Kim, Wonjung

    2015-11-01

    We present a novel paper-based flow fractionation system for preconcentration and field-flow fractionation. The paper fluidic system consisting of a straight channel connected with expansion regions can generate a fluid flow with a constant flow rate for 10 min without any external pumping devices. The flow bifurcates with a fraction ratio of up to 30 depending on the control parameters of the channel geometry. Utilizing this simple paper-based bifurcation system, we developed a continuous-flow preconcentrator and a field-flow fractionator on a paper platform. Our experimental results show that the continuous-flow preconcentrator can produce a 33-fold enrichment of the ion concentration and that the flow fractionation system successfully separates the charged dyes. Our study suggests simple, cheap ways to construct preconcentration and field-flow fractionation systems for paper-based microfluidic diagnostic devices. This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIP) (NRF-2015R1A2A2A04006181).

  10. Performance evaluation of the pilot-scale, double-shell tank ventilation system using simulated aerosol streams

    SciTech Connect

    Brouns, T.M.; Peterson, M.E.

    1989-12-01

    Radioactive waste slurries are currently being stored in underground tanks on the Hanford Site. The slurries that are being stored in the double-shell tanks (DSTs) are various mixtures of radioactive solids, liquids, and aqueous wastes. The tanks must be maintained at a negative pressure relative to atmospheric pressure to safeguard against pressurization and the subsequent leakage of entrained radioactive aerosols to the environment. A ventilation system must be capable of withdrawing the total volume of off gas generated from the tanks while maintaining the tanks at a negative pressure. Westinghouse Hanford Company (WHC) has identified a need to improve the efficiency of the ventilation system being used on the tank farms to meet the more restrictive release limits for radioactive isotopes. Kaiser Engineers Hanford Company (KEH) has been contracted by WHC to design the new ventilation system for the existing tank farms. WHC contracted the Pacific Northwest Laboratory (PNL) to fabricate and test the prototypic pilot-scale design prior to finalizing the design of the ventilation system. The PNL has conducted tests to determine (1) the effectiveness of the system for removal of vapors condensable at 35{degrees}F, (2) the effectiveness for removal of soluble and insoluble aerosols, and (3) the life span of the mist eliminators to be used in the new system. The results of extensive testing of the pilot-scale system with condensables and both soluble and insoluble aerosols are presented in this report. 7 refs., 25 figs., 8 tabs.

  11. Cellular Dose of Partly Soluble Cu Particle Aerosols at the Air–Liquid Interface Using an In Vitro Lung Cell Exposure System

    PubMed Central

    Cronholm, Pontus; Karlsson, Hanna L.; Midander, Klara; Odnevall Wallinder, Inger; Möller, Lennart

    2013-01-01

    Abstract Background There is currently a need to develop and test in vitro systems for predicting the toxicity of nanoparticles. One challenge is to determine the actual cellular dose of nanoparticles after exposure. Methods In this study, human epithelial lung cells (A549) were exposed to airborne Cu particles at the air–liquid interface (ALI). The cellular dose was determined for two different particle sizes at different deposition conditions, including constant and pulsed Cu aerosol flow. Results Airborne polydisperse particles with a geometric mean diameter (GMD) of 180 nm [geometric standard deviation (GSD) 1.5, concentration 105 particles/mL] deposited at the ALI yielded a cellular dose of 0.4–2.6 μg/cm2 at pulsed flow and 1.6–7.6 μg/cm2 at constant flow. Smaller polydisperse particles in the nanoregime (GMD 80 nm, GSD 1.5, concentration 107 particles/mL) resulted in a lower cellular dose of 0.01–0.05 μg/cm2 at pulsed flow, whereas no deposition was observed at constant flow. Exposure experiments with and without cells showed that the Cu particles were partly dissolved upon deposition on cells and in contact with medium. Conclusions Different cellular doses were obtained for the different Cu particle sizes (generated with different methods). Furthermore, the cellular doses were affected by the flow conditions in the cell exposure system and the solubility of Cu. The cellular doses of Cu presented here are the amount of Cu that remained on the cells after completion of an experiment. As Cu particles were partly dissolved, Cu (a nonnegligible contribution) was, in addition, present and analyzed in the nourishing medium present beneath the cells. This study presents cellular doses induced by Cu particles and demonstrates difficulties with deposition of nanoparticles at the ALI and of partially soluble particles. PMID:22889118

  12. Influence of inspiratory flow rate, particle size, and airway caliber on aerosolized drug delivery to the lung.

    PubMed

    Dolovich, M A

    2000-06-01

    A number of studies in the literature support the use of fine aerosols of drug, inhaled at low IFRs to target peripheral airways, with the objective of improving clinical responses to inhaled therapy (Fig. 8). Attempts have been made to separate response due to changes in total administered dose or the surface concentration of the dose from response due to changes in site of deposition--both are affected by the particle size of the aerosol, with IFR additionally influencing the latter. The tools for measuring dose and distribution have improved over the last 10-15 years, and thus we should expect greater accuracy in these measurements for assessing drug delivery to the lung. There are still issues, though, in producing radiolabeled (99m)technetium aerosols that are precise markers for the pharmaceutical product being tested and in quantitating absolute doses deposited in the lung. PET isotopes may provide the means for directly labelling a drug and perhaps can offer an alternative for making these measurements in the future, but deposition measurements should not be used in isolation; protocols should incorporate clinical tests to provide parallel therapeutic data in response to inhalation of the drug by the various patient populations being studied. PMID:10894453

  13. Continuous air monitor for alpha-emitting aerosol particles

    SciTech Connect

    McFarland, A.R.; Ortiz, C.A. . Dept. of Mechanical Engineering); Rodgers, J.C.; Nelson, D.C. )

    1990-01-01

    A new alpha Continuous Air Monitor (CAM) sampler is being developed for use in detecting the presence of alpha-emitting aerosol particles. The effort involves design, fabrication and evaluation of systems for the collection of aerosol and for the processing of data to speciate and quantify the alpha emitters of interest. At the present time we have a prototype of the aerosol sampling system and we have performed wind tunnel tests to characterize the performance of the device for different particle sizes, wind speeds, flow rates and internal design parameters. The results presented herein deal with the aerosol sampling aspects of the new CAM sampler. Work on the data processing, display and alarm functions is being done in parallel with the particle sampling work and will be reported separately at a later date. 17 refs., 5 figs., 3 tabs.

  14. FlowSim/FlowRisk: A code system for studying risk associated with material process flows

    SciTech Connect

    Kaufman, A.M.

    1993-10-01

    The need to study and assess life-cycle risks of Pu release by nuclear warheads during peace time lead to the development of a code suite which could model day to day operations involving nuclear weapons and calculate the associated risk involved in these proceedings. The life-cycle study called LIONSHARE is described in Reference 1. The code that models the flow is called FlowSim. The code that evaluates the associated risk is called FlowRisk. We shall concentrate here on the methodology used by FlowSim in modeling material flows. FlowRisk, mainly a postprocessor of FlowSim runs, will be dealt with in less detail.

  15. A comparative flow visualization study of thermocapillary flow in drops in liquid-liquid systems

    NASA Technical Reports Server (NTRS)

    Balasubramaniam, R.; Rashidnia, N.

    1991-01-01

    Experiments are performed to visualize thermocapillary flow in drops in an immiscible host liquid. The host liquid used is silicone oil. Drops of three different liquids are used, viz, vegetable oil, water-methanol mixture anad pure methanol. Clear evidence of thermocapillary flow is seen in vegetable oil drops. For a mixture of water and methanol (approximately 50-50 by weight), natural convection is seen to dominate the flow outside the drop. Pure methanol drops exhibit thermocapillary flow, but dissolve in silicone oil. A small amount of water added to pure methanol significantly reduces the dissolution. Flow oscillations occur in this system for both isothermal and non-isothermal conditions.

  16. Methods and Tools to allow molecular flow simulations to be coupled to higher level continuum descriptions of flows in porous/fractured media and aerosol/dust dynamics

    SciTech Connect

    Loyalka, Sudarshan

    2015-04-09

    The purpose of this project was to develop methods and tools that will aid in safety evaluation of nuclear fuels and licensing of nuclear reactors relating to accidents.The objectives were to develop more detailed and faster computations of fission product transport and aerosol evolution as they generally relate to nuclear fuel and/or nuclear reactor accidents. The two tasks in the project related to molecular transport in nuclear fuel and aerosol transport in reactor vessel and containment. For both the tasks, explorations of coupling of Direct Simulation Monte Carlo with Navier-Stokes solvers or the Sectional method were not successful. However, Mesh free methods for the Direct Simulation Monte Carlo method were successfully explored.These explorations permit applications to porous and fractured media, and arbitrary geometries.The computations were carried out in Mathematica and are fully parallelized. The project has resulted in new computational tools (algorithms and programs) that will improve the fidelity of computations to actual physics, chemistry and transport of fission products in the nuclear fuel and aerosol in reactor primary and secondary containments.

  17. A direct method for e-cigarette aerosol sample collection.

    PubMed

    Olmedo, Pablo; Navas-Acien, Ana; Hess, Catherine; Jarmul, Stephanie; Rule, Ana

    2016-08-01

    E-cigarette use is increasing in populations around the world. Recent evidence has shown that the aerosol produced by e-cigarettes can contain a variety of toxicants. Published studies characterizing toxicants in e-cigarette aerosol have relied on filters, impingers or sorbent tubes, which are methods that require diluting or extracting the sample in a solution during collection. We have developed a collection system that directly condenses e-cigarette aerosol samples for chemical and toxicological analyses. The collection system consists of several cut pipette tips connected with short pieces of tubing. The pipette tip-based collection system can be connected to a peristaltic pump, a vacuum pump, or directly to an e-cigarette user for the e-cigarette aerosol to flow through the system. The pipette tip-based system condenses the aerosol produced by the e-cigarette and collects a liquid sample that is ready for analysis without the need of intermediate extraction solutions. We tested a total of 20 e-cigarettes from 5 different brands commercially available in Maryland. The pipette tip-based collection system condensed between 0.23 and 0.53mL of post-vaped e-liquid after 150 puffs. The proposed method is highly adaptable, can be used during field work and in experimental settings, and allows collecting aerosol samples from a wide variety of e-cigarette devices, yielding a condensate of the likely exact substance that is being delivered to the lungs. PMID:27200479

  18. Responding to detection of aerosolized Bacillus anthracis by autonomous detection systems in the workplace.

    PubMed

    Meehan, Patrick J; Rosenstein, Nancy E; Gillen, Matthew; Meyer, Richard F; Kiefer, Max J; Deitchman, Scott; Besser, Richard E; Ehrenberg, Richard L; Edwards, Kathleen M; Martinez, Kenneth F

    2004-06-01

    Autonomous detection systems (ADSs) are under development to detect agents of biologic and chemical terror in the environment. These systems will eventually be able to detect biologic and chemical hazards reliably and provide approximate real-time alerts that an agent is present. One type of ADS that tests specifically for Bacillus anthracis is being deployed in hundreds of postal distribution centers across the United States. Identification of aerosolized B. anthracis spores in an air sample can facilitate prompt on-site decontamination of workers and subsequent administration of postexposure prophylaxis to prevent inhalational anthrax. Every employer who deploys an ADS should develop detailed plans for responding to a positive signal. Responding to ADS detection of B. anthracis involves coordinating responses with community partners and should include drills and exercises with these partners. This report provides guidelines in the following six areas: 1) response and consequence management planning, including the minimum components of a facility response plan; 2) immediate response and evacuation; 3) decontamination of potentially exposed workers to remove spores from clothing and skin and prevent introduction of B. anthracis into the worker's home and conveyances; 4) laboratory confirmation of an ADS signal; 5) steps for evaluating potentially contaminated environments; and 6) postexposure prophylaxis and follow-up. PMID:15179360

  19. Remote sensing of tropospheric gases and aerosols with airborne DIAL system

    NASA Technical Reports Server (NTRS)

    Browell, E. V.

    1983-01-01

    The multipurpose airborne DIAL system developed at NASA Langley Research Center is characterized, and the published results of tropospheric O3, H2O, and aerosol-backscatter remote-sensing experiments performed in 1980 and 1981 are summarized. The system comprises two tunable dye lasers pumped by frequency-doubled Nd:YAG lasers, dielectric-coated steering optics, a 36-cm-diameter Cassegrain receiver telescope, gateable photomultiplier tubes, and a minicomputer data-processing unit for real-time calculation of gas concentrations and backscattering profiles. The transmitted energy of the 100-microsec-separated dye-laser pulses is 40, 80, or 50 mJ/pulse at around 300, 600, or 720-nm wavelength, respectively. Good agreement was found between DIAL-remote-sensed and in-situ H2O and O3 profiles of the lower troposphere and O3 profiles of the tropopause region, and the usefulness of DIAL backscattering measurements in the study of boundary-layer and tropospheric dynamics is demonstrated. The feasibility of DIAL sensing of power-plant or urban plume SO2, of urban-area (or rural-area column-content) NO2, and of temperature and H2O (simultaneously using a third laser) has been suggested by simulation studies.

  20. Flow cytometer acquisition and detection system

    SciTech Connect

    Casstevens, Martin K.; Burzynski, Ryszard; Weibel, John; Kachynski, Alexander

    2010-05-04

    A flow cytometer has a flow cell through which a sample flows and at least one laser emitting an excitation beam for illuminating a corresponding interrogation region in the flow cell. Scattered and fluorescence light from each interrogation region is collected by one or more input fibers for that region, and the input fiber(s) are fed to a dispersion module for that interrogation region that disperses the incoming light into different spectral regions. The dispersed light is conveyed, such as by a plurality of output fibers, to one or more photosensitive detectors. Thus, time multiplexed light signals may be delivered to a detector whereby several unique light signals can be measured by a single detector.

  1. Organic aerosols

    SciTech Connect

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN.

  2. Development of an aerosol-chemistry transport model coupled to non-hydrostatic icosahedral atmospheric model (NICAM) through applying a stretched grid system to regional simulations around Japan

    NASA Astrophysics Data System (ADS)

    Goto, D.; Nakajima, T.; Masaki, S.

    2014-12-01

    Air pollution has a great impact on both climate change and human health. One effective way to tackle with these issues is a use of atmospheric aerosol-chemistry models with high-resolution in a global scale. For this purpose, we have developed an aerosol-chemistry model based on a global cloud-resolving model (GCRM), Nonhydrostatic Icosahedral Atmospheric Model (NICAM; Tomita and Satoh, Fluid. Dyn. Res. 2004; Satoh et al., J. Comput. Phys. 2008, PEPS, 2014) under MEXT/RECCA/SALSA project. In the present study, we have simulated aerosols and tropospheric ozone over Japan by our aerosol-chemistry model "NICAM-Chem" with a stretched-grid system of approximately 10 km resolution, for saving the computer resources. The aerosol and chemistry modules are based on Spectral Radiation-Transport Model for Aerosol Species (SPRINTARS; Takemura et al., J. Geophys. Res., 2005) and Chemical AGCM for Study of Atmospheric Environment and Radiative Forcing (CHASER; Sudo et al., J. Geophys. Res., 2002). We found that our model can generally reproduce both aerosols and ozone, in terms of temporal variations (daily variations of aerosols and diurnal variations of ozone). Under MEXT/RECCA/SALSA project, we also have used these results obtained by NICAM-Chem for the assessment of their impact on human health.

  3. A technical feasibility study of dornase alfa delivery with eFlow® vibrating membrane nebulizers: aerosol characteristics and physicochemical stability.

    PubMed

    Scherer, Thomas; Geller, David E; Owyang, Laura; Tservistas, Marcus; Keller, Manfred; Boden, Norbert; Kesser, Kenneth C; Shire, Steven J

    2011-01-01

    Dornase alfa (Pulmozyme®) is an inhaled mucus-active drug that decreases viscoelasticity of sputum in vitro, improves lung function and reduces respiratory exacerbations in cystic fibrosis (CF) patients of 5 years age and older. The regulatory approval of dornase alfa 15 years ago stipulated that only certain jet nebulizer-compressor combinations should be used to deliver the drug. Since that time there have been significant advances in aerosol delivery technology, including development of electronic perforated vibrating membrane devices. Three independent laboratories studied aerosol characteristics, nebulization time, dose delivery, and stability of dornase alfa after nebulization to determine the feasibility of using perforated vibrating membrane devices to deliver the drug. These studies determined that the eFlow® vibrating membrane technology delivers dornase alfa more rapidly and efficiently than jet nebulizers, and does not affect the physicochemical properties of the drug. These in vitro results demonstrate only the technical feasibility of using vibrating membrane devices to deliver dornase alfa. Clinical studies will be required before any conclusions can be made regarding clinical safety and efficacy of these drug-device combinations for cystic fibrosis. PMID:20533437

  4. Schlieren System For Flow Studies In Round Glass Pipes

    NASA Technical Reports Server (NTRS)

    Costen, Robert C.; Rhodes, David B.; Jones, Stephen B.

    1990-01-01

    In schlieren system for studying flow of gas in transparent pipe of circular cross section, cylindrical lenses placed on opposite sides of pipe compensate for refraction caused by wall of pipe. Enables direct visualization of such phenomena as laminar or turbulent flow, shock waves, vortexes, and flow separations in systems having inherently cylindrical geometry; potentially unreliable extrapolations from results in flat-sided test cells no longer necessary.

  5. Simulation studies on shape and growth kinetics for fractal aggregates in aerosol and colloidal systems

    NASA Astrophysics Data System (ADS)

    Heinson, William Raymond

    The aim of this work is to explore, using computational techniques that simulate the motion and subsequent aggregation of particles in aerosol and colloidal systems, many common but not well studied systems that form fractal clusters. Primarily the focus is on cluster shape and growth kinetics. The structure of clusters made under diffusion limited cluster-cluster aggregation (DLCA) is looked at. More specifically, the shape anisotropy is found to have an inverse relationship on the scaling prefactor k0 and have no effect on the fractal dimension Df . An analytical model that predicts the shape and fractal dimension of diffusion limited cluster-cluster aggregates is tested and successfully predicts cluster shape and dimensionality. Growth kinetics of cluster-cluster aggregation in the free molecular regime where the system starts with ballistic motion and then transitions to diffusive motion as the aggregates grow in size is studied. It is shown that the kinetic exponent will crossover from the ballistic to the diffusional values and the onset of this crossover is predicted by when the nearest neighbor Knudsen number reaches unity. Simulations were carried out for a system in which molten particles coalesce into spheres, then cool till coalescing stops and finally the polydispersed monomers stick at point contacts to form fractal clusters. The kinetic exponent and overall cluster structure for these aggregates was found to be in agreement with DLCA that started with monodispersed monomers. Colloidal aggregation in the presence of shear was studied in detail. Study of a colloidal system characterized a by short-range attractive potential showed that weak shear enhanced the aggregation process. Strong shear led to fragmentation and subsequent nucleation as cluster growth rebounded after an induction time.

  6. Impact of Aerosols and Atmospheric Thermodynamics on Cloud Properties within the Climate System

    NASA Technical Reports Server (NTRS)

    Matsui, Toshihisa; Masunaga, Hirohiko; Pielke, Roger, Sr.; Tao, Wei-Kuo

    2003-01-01

    A combination of cloud-top and columnar droplet sizes derived from the multi Tropical Rainfall Measurement Mission (TRMM) sensors reveals the sensitivity of the aerosols effect on cloud-precipitation process due to environmental vertical thermodynamic structure. First, the magnitude of aerosol indirect effect could be larger with the analysis of columnar droplet sizes than that derived from the cloud-top droplet sizes, since column-droplet size can account for the broader droplet spectra in the cloud layers. Second, a combination of cloud- top and columnar droplet sizes reveals that the warm rain process is prevented regardless of the aerosols concentration under a high static stability such as when a strong temperature inversion exists, while a high aerosol concentration suppresses the warm rain formulation under a low static stability.

  7. Paper-Based Flow Fractionation System Applicable to Preconcentration and Field-Flow Separation.

    PubMed

    Hong, Seokbin; Kwak, Rhokyun; Kim, Wonjung

    2016-02-01

    We present a novel paper-based flow fractionation system for preconcentration and field-flow separation. In this passive fluidic device, a straight channel is divided into multiple daughter channels, each of which is connected with an expanded region. The hydrodynamic resistance of the straight channel is predominant compared with those of expanded regions, so we can create steady flows through the straight and daughter channels. While the expanded regions absorb a great amount of water via capillarity, the steady flow continues for 10 min without external pumping devices. By controlling the relative hydrodynamic resistances of the daughter channels, we successfully divide the flow with flow rate ratios of up to 30. Combining this bifurcation system with ion concentration polarization (ICP), we develop a continuous-flow preconcentrator on a paper platform, which can preconcentrate a fluorescent dye up to 33-fold. In addition, we construct a field-flow separation system to divide two different dyes depending on their electric polarities. Our flow fractionation systems on a paper-based platform would make a breakthrough for point-of-care diagnostics with specific functions including preconcentration and separation. PMID:26713779

  8. Sensitivity studies using Regional Atmospheric Modeling System to analyze the impact of dust and aerosol on precipitation in the Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Jha, V.; Cotton, W. R.; Carrio, G. G.; Pierce, J. R.

    2015-12-01

    A modeling study is performed in the Colorado River Basin by varying the ratio of dust and aerosol pollution. The Colorado State University Regional Atmospheric Modeling system (RAMS) version 6.0 is used for the analyses with the aerosol and dust pollution data being nudged from the GEOS-Chem. RAMS was modified to ingest GEOS-CHEM output data and periodically update aerosol fields. GEOS-CHEM is a chemical transport model which uses assimilated meteorological data from the NASA Goddard Earth Observation System (GEOS). The aerosol data comprise a sum of hydrophobic and hydrophilic black carbon and organic aerosol, hydrophilic SOAs, hydrocarbon oxidation and inorganic aerosols (nitrate, sulfate and ammonium). In addition, a RAMS-based dust source and transport model is used. The sensitivity studies are 5 different kinds. The base study has both the dust and aerosol pollution data ON. The Case 2 has dust OFF with only the aerosol sources ON. The Case 3 has the aerosol sources ON with dust multiplied by a factor of 3. Case 4 has the aerosol sources ON with dust multiplied by a factor of 10. Case 5 and Case 6 are the simulations where dust can act only as CCN and only as IN respectively. It was found that the precipitation increases when dust is increased 3 times. However, the response is non-monotonic when dust is increased 10 times and the response depends on the environmental conditions. Dust acting as CCN acts in opposition to dust acting as IN. In general, dust acting as IN tends to enhance precipitation in wintertime orographic clouds.

  9. Position paper -- Tank ventilation system design air flow rates

    SciTech Connect

    Goolsby, G.K.

    1995-01-04

    The purpose of this paper is to document a project position on required ventilation system design air flow rates for the waste storage tanks currently being designed by project W-236A, the Multi-Function Waste Tank Facility (MWTF). The Title 1 design primary tank heat removal system consists of two systems: a primary tank vapor space ventilation system; and an annulus ventilation system. At the conclusion of Title 1 design, air flow rates for the primary and annulus ventilation systems were 960 scfm and 4,400 scfm, respectively, per tank. These design flow rates were capable of removing 1,250,000 Btu/hr from each tank. However, recently completed and ongoing studies have resulted in a design change to reduce the extreme case heat load to 700,000 Btu/hr. This revision of the extreme case heat load, coupled with results of scale model evaporative testing performed by WHC Thermal Hydraulics, allow for a reduction of the design air flow rates for both primary and annulus ventilation systems. Based on the preceding discussion, ICF Kaiser Hanford Co. concludes that the design should incorporate the following design air flow rates: Primary ventilation system--500 scfm maximum and Annulus ventilation system--1,100 scfm maximum. In addition, the minimum air flow rates in the primary and annulus ventilation systems will be investigated during Title 2 design. The results of the Title 2 investigation will determine the range of available temperature control using variable air flows to both ventilation systems.

  10. Heat transfer analysis for peripheral blood flow measurement system

    NASA Astrophysics Data System (ADS)

    Nagata, Koji; Hattori, Hideharu; Sato, Nobuhiko; Ichige, Yukiko; Kiguchi, Masashi

    2009-06-01

    Some disorders such as circulatory disease and metabolic abnormality cause many problems to peripheral blood flow condition. Therefore, frequent measurement of the blood flow condition is bound to contribute to precaution against those disorders and to control of conditions of the diseases. We propose a convenient means of blood flow volume measurement at peripheral part, such as fingertips. Principle of this measurement is based on heat transfer characteristics of peripheral part containing the blood flow. Transition response analysis of skin surface temperature has provided measurement model of the peripheral blood flow volume. We developed the blood flow measurement system based on that model and evaluated it by using artificial finger under various temperature conditions of ambience and internal fluid. The evaluation results indicated that proposed method could estimate the volume of the fluid regardless of temperature condition of them. Finally we applied our system to real finger testing and have obtained results correlated well with laser Doppler blood flow meter values.

  11. A novel in vitro flow system for changing flow direction on endothelial cells

    PubMed Central

    Wang, Chong; Lu, Hao; Schwartz, Martin Alexander

    2012-01-01

    Atherosclerotic plaques localize to regions of flow disturbance, i.e. bifurcations, branch points and regions of high curvature. Shear stress in these regions can be multi-directional due to complex flow patterns such as time-varying vortices. However, commonly used in vitro flow models are incapable of changing flow orientation to any direction other than the reverse. We have developed a novel in vitro flow system to enable changes in flow direction to any angle. When cells were pre-aligned in laminar shear, then rotated 90°, cells re-aligned over 24 hours. Re-alignment involved actin remodeling by gradual rotation of actin stress fibers. This device will enable analysis of how endothelial cells sense changes in flow direction as occur in vivo. PMID:22386042

  12. Breakthrough Flow Battery Cell Stack: Transformative Electrochemical Flow Storage System (TEFSS)

    SciTech Connect

    2010-09-09

    GRIDS Project: UTRC is developing a flow battery with a unique design that provides significantly more power than today's flow battery systems. A flow battery is a cross between a traditional battery and a fuel cell. Flow batteries store their energy in external tanks instead of inside the cell itself. Flow batteries have traditionally been expensive because the battery cell stack, where the chemical reaction takes place, is costly. In this project, UTRC is developing a new stack design that achieves 10 times higher power than today’s flow batteries. This high power output means the size of the cell stack can be smaller, reducing the amount of expensive materials that are needed. UTRC’s flow battery will reduce the cost of storing electricity for the electric grid, making widespread use feasible.

  13. NASA GES DISC Level 2 Aerosol Analysis and Visualization Services

    NASA Technical Reports Server (NTRS)

    Wei, Jennifer; Petrenko, Maksym; Ichoku, Charles; Yang, Wenli; Johnson, James; Zhao, Peisheng; Kempler, Steve

    2015-01-01

    Overview of NASA GES DISC Level 2 aerosol analysis and visualization services: DQViz (Data Quality Visualization)MAPSS (Multi-sensor Aerosol Products Sampling System), and MAPSS_Explorer (Multi-sensor Aerosol Products Sampling System Explorer).

  14. A Marine Aerosol Reference Tank system as a breaking wave analogue

    NASA Astrophysics Data System (ADS)

    Stokes, M. D.; Deane, G. B.; Prather, K.; Bertram, T. H.; Ruppel, M. J.; Ryder, O. S.; Brady, J. M.; Zhao, D.

    2012-12-01

    In order to better understand the processes governing the production of marine aerosols a repeatable, controlled method for their generation is required. The Marine Aerosol Reference Tank (MART) has been designed to closely approximate oceanic conditions by producing an evolving bubble plume and surface foam patch. The tank utilizes an intermittently plunging sheet of water and large volume tank reservoir to simulate turbulence, plume and foam formation, and is monitored volumetrically and acoustically to ensure the repeatability of conditions.

  15. THE CONTINUOUS FLOW ANALYZER AUTOMATION SYSTEM. PART I - FUNCTIONAL SPECIFICATIONS

    EPA Science Inventory

    This document contains the project definition, the functional requirements, and the functional design for a proposed computer automation system for the continuous flow analyzer. The proposed system will accomplish real-time data acquisition, calibration, baseline correction, calc...

  16. INNOVATIVE URBAN WET-WEATHER FLOW MANAGEMENT SYSTEMS

    EPA Science Inventory

    This report describes innovative methods to improve wet weather flow (WWF) management systems, that provide drainage services at the same time as decreasing stormwater pollutant discharges, for urban developments of the 21st century. Traditionally, wet-weather collection systems...

  17. Lifting options for stratospheric aerosol geoengineering: advantages of tethered balloon systems.

    PubMed

    Davidson, Peter; Burgoyne, Chris; Hunt, Hugh; Causier, Matt

    2012-09-13

    The Royal Society report 'Geoengineering the Climate' identified solar radiation management using albedo-enhancing aerosols injected into the stratosphere as the most affordable and effective option for geoengineering, but did not consider in any detail the options for delivery. This paper provides outline engineering analyses of the options, both for batch-delivery processes, following up on previous work for artillery shells, missiles, aircraft and free-flying balloons, as well as a more lengthy analysis of continuous-delivery systems that require a pipe connected to the ground and supported at a height of 20 km, either by a tower or by a tethered balloon. Towers are shown not to be practical, but a tethered balloon delivery system, with high-pressure pumping, appears to have much lower operating and capital costs than all other delivery options. Instead of transporting sulphuric acid mist precursors, such a system could also be used to transport slurries of high refractive index particles such as coated titanium dioxide. The use of such particles would allow useful experiments on opacity, coagulation and atmospheric chemistry at modest rates so as not to perturb regional or global climatic conditions, thus reducing scale-up risks. Criteria for particle choice are discussed, including the need to minimize or prevent ozone destruction. The paper estimates the time scales and relatively modest costs required if a tethered balloon system were to be introduced in a measured way with testing and development work proceeding over three decades, rather than in an emergency. The manufacture of a tether capable of sustaining the high tensions and internal pressures needed, as well as strong winds, is a significant challenge, as is the development of the necessary pumping and dispersion technologies. The greatest challenge may be the manufacture and launch of very large balloons, but means have been identified to significantly reduce the size of such balloons or aerostats

  18. Turbulent plane Couette flow subject to strong system rotation

    NASA Astrophysics Data System (ADS)

    Bech, Knut H.; Andersson, Helge I.

    1997-09-01

    System rotation is known to substantially affect the mean flow pattern as well as the turbulence structure in rotating channel flows. In a numerical study of plane Couette flow rotating slowly about an axis aligned with the mean vorticity, Bech & Andersson (1996a) found that the turbulence level was damped in the presence of anticyclonic system rotation, in spite of the occurrence of longitudinal counter-rotating roll cells. Moreover, the turbulence anisotropy was practically unaffected by the weak rotation, for which the rotation number Ro, defined as the ratio of twice the imposed angular vorticity [Omega] to the shear rate of the corresponding laminar flow, was ±0.01. The aim of the present paper is to explore the effects of stronger anticyclonic system rotation on directly simulated turbulent plane Couette flow. Turbulence statistics like energy, enstrophy and Taylor lengthscales, both componental and directional, were computed from the statistically steady flow fields and supplemented by structural information obtained by conditional sampling.

  19. Cloud, fog, and aerosol effect on the MTF of optical systems

    NASA Astrophysics Data System (ADS)

    Ben-Dor, Baruch; Bruscaglioni, Piero; Devir, Adam D.; Donelli, P.; Ismaelli, A.

    1995-12-01

    A numerical code is used to examine the features of the effect of atmospheric turbidity on the modulation transfer function of an optical system operating on ground, on an airplane or a satellite. Models of size distributions and optical properties of particulate suspended in the atmosphere are considered. The relevant scattering phase functions are calculated by Mie theory and are later used by a code using both Monte Carlo and geometrical optics procedures to evaluate the contribution of atmospheric turbidity to the augmentation of the point spread function. Comparison of ours with other researchers procedures is shown. The effect of atmospheric turbidity is evaluated as due to the presence of scatterers (the secondary sources) whose defocused images are distributed on the plane of the image of the primary source. The positions of the scatterers are determined by a Monte Carlo procedure, while the contribution of each secondary source to the irradiance on the image plane is evaluated by means of geometrical optics. Cases of different aerosols types, geometry aspects of viewing through the atmosphere and atmospheric absorption effects on the MTF are shown.

  20. Heat flow in the Keweenawan rift system

    NASA Astrophysics Data System (ADS)

    Perry, C.; Mareschal, J.; Jaupart, C. P.

    2012-12-01

    The emplacement of large volumes of mafic volcanic rocks during the Keweenawan rifting has modified the average crustal composition and affects the present steady state heat flux in the region. We have combined new heat flux measurements in the Superior Province of the Canadian Shield and previously published data to characterize the heat flux field around the Keweenawan rift system. For the Nipigon embayment, North of lake Superior in Ontario, mafic intrusions associated with the Keweenawan rifting have resulted in an increase in the volume of mafic rocks in the crust and caused a very small <3mW m-2 decrease in the mean heat flux. There is a very marked decrease in the heat flux (Δ Q ≈ 20mW m-2) beneath the western half of Lake Superior and to the west. The very low values of the surface heat flux (≈ 22mW m-2 correlate with the maximum Bouguer gravity anomaly. The heat flux at the base of the crust in the Canadian Shield has been determined from surface heat flux, heat production, and crustal stucture to be ≈ 15 mW m-2. In the Keweenawan rift, the surface heat flux is only a few mW m-2 higher than the mantle heat flux, which implies that the contribution of the entire crustal column to the surface heat flux is small and that the crust is exclusively made up of depleted mafic volcanic rocks. In the eastern part and northeast of Lake Superior, there is a marked increase in heat flux that correlates with a lower Bouguer anomaly. Local high heat flux anomalies due to intrusions by felsic rocks are superposed with a long wavelength trend of higher heat flow suggesting a more felsic crustal composition in the eastern part of the Keweenawan rift. Simple models suggest that such a thick dense volcanic pile as accumulated in the Keweenawan rift is almost invariably unstable and that very particular conditions were required for it to stabilize in the crust.

  1. On-the-fly cross flow laser guided separation of aerosol particles based on size, refractive index and density-theoretical analysis.

    PubMed

    Lall, A A; Terray, A; Hart, S J

    2010-12-20

    Laser separation of particles is achieved using forces resulting from the momentum exchange between particles and photons constituting the laser radiation. Particles can experience different optical forces depending on their size and/or optical properties, such as refractive index. Thus, particles can move at different speeds in the presence of an optical force, leading to spatial separations. In this paper, we present a theoretical analysis on laser separation of non-absorbing aerosol particles moving at speeds (1-10 cm/sec) which are several orders of magnitude greater than typical particle speeds used in previous studies in liquid medium. The calculations are presented for particle deflection by a loosely focused Gaussian 1064 nm laser, which simultaneously holds and deflects particles entrained in flow perpendicular to their direction of travel. The gradient force holds the particles against the viscous drag for a short period of time. The scattering force simultaneously pushes the particles, perpendicular to the flow, during this period. Our calculations show particle deflections of over 2500 µm for 15 µm aerosol particles, and a separation of over 1500 µm between 5 µm and 10 µm particles when the laser is operated at 10 W. We show that a separation of about 421 µm can be achieved between two particles of the same size (10 µm) but having a refractive index difference of 0.1. Density based separations are also possible. Two 10 µm particles with a density difference of 600 kg/m3 can be separated by 193 µm. Examples are shown for separation distances between polystyrene, poly(methylmethacrylate), silica and water particles. These large laser guided deflections represent a novel achievement for optical separation in the gas phase. PMID:21196954

  2. The Airborne Cloud-Aerosol Transport System. Part I; Overview and Description of the Instrument and Retrival Algorithms

    NASA Technical Reports Server (NTRS)

    Yorks, John E.; Mcgill, Matthew J.; Scott, V. Stanley; Kupchock, Andrew; Wake, Shane; Hlavka, Dennis; Hart, William; Selmer, Patrick

    2014-01-01

    The Airborne Cloud-Aerosol Transport System (ACATS) is a multi-channel Doppler lidar system recently developed at NASA Goddard Space Flight Center (GSFC). A unique aspect of the multi-channel Doppler lidar concept such as ACATS is that it is also, by its very nature, a high spectral resolution lidar (HSRL). Both the particulate and molecular scattered signal can be directly and unambiguously measured, allowing for direct retrievals of particulate extinction. ACATS is therefore capable of simultaneously resolving the backscatterextinction properties and motion of a particle from a high altitude aircraft. ACATS has flown on the NASA ER-2 during test flights over California in June 2012 and science flights during the Wallops Airborne Vegetation Experiment (WAVE) in September 2012. This paper provides an overview of the ACATS method and instrument design, describes the ACATS retrieval algorithms for cloud and aerosol properties, and demonstrates the data products that will be derived from the ACATS data using initial results from the WAVE project. The HSRL retrieval algorithms developed for ACATS have direct application to future spaceborne missions such as the Cloud-Aerosol Transport System (CATS) to be installed on the International Space Station (ISS). Furthermore, the direct extinction and particle wind velocity retrieved from the ACATS data can be used for science applications such 27 as dust or smoke transport and convective outflow in anvil cirrus clouds.

  3. Numerical modelling of the work of a pulsed aerosol system for fire fighting at the ignitions of liquid hydrocarbon fuels

    NASA Astrophysics Data System (ADS)

    Rychkov, A. D.

    2009-06-01

    The work of a pulsed aerosol system for fire fighting is modelled, which is designed for fire fighting at oil storages and at the spills of oil products, whose vapors were modelled by gaseous methane. The system represents a device for separate installation, which consists of a charge of solid propellant (the gas generator) and a container with fine-dispersed powder of the flame-damper substance. The methane combustion was described by a one-stage gross-reaction, the influence of the concentration of vapors of the flame-damper substance on the combustion process was taken into account by reducing the pre-exponent factor in the Arrhenius law and was described by an empirical dependence. The computational experiment showed that the application of the pulsed aerosol system for fire fighting ensures an efficient transport of fine-dispersed aerosol particles of the flame-damping substance and its forming vapors to the combustion zone; the concentration of particles ensures the damping of the heat source.

  4. SAGE II aerosol data validation based on retrieved aerosol model size distribution from SAGE II aerosol measurements

    NASA Technical Reports Server (NTRS)

    Wang, Pi-Huan; Mccormick, M. P.; Mcmaster, L. R.; Chu, W. P.; Swissler, T. J.; Osborn, M. T.; Russell, P. B.; Oberbeck, V. R.; Livingston, J.; Rosen, J. M.

    1989-01-01

    Consideration is given to aerosol correlative measurements experiments for the Stratospheric Aerosol and Gas Experiment (SAGE) II, conducted between November 1984 and July 1986. The correlative measurements were taken with an impactor/laser probe, a dustsonde, and an airborne 36-cm lidar system. The primary aerosol quantities measured by the ground-based instruments are compared with those calculated from the aerosol size distributions from SAGE II aerosol extinction measurements. Good agreement is found between the two sets of measurements.

  5. Heterogeneous interaction of SiO2 with N2O5: aerosol flow tube and single particle optical levitation-Raman spectroscopy studies.

    PubMed

    Tang, M J; Camp, J C J; Rkiouak, L; McGregor, J; Watson, I M; Cox, R A; Kalberer, M; Ward, A D; Pope, F D

    2014-09-25

    Silica (SiO2) is an important mineral present in atmospheric mineral dust particles, and the heterogeneous reaction of N2O5 on atmospheric aerosol is one of the major pathways to remove nitrogen oxides from the atmosphere. The heterogeneous reaction of N2O5 with SiO2 has only been investigated by two studies previously, and the reported uptake coefficients differ by a factor of >10. In this work two complementary laboratory techniques were used to study the heterogeneous reaction of SiO2 particles with N2O5 at room temperature and at different relative humidities (RHs). The uptake coefficients of N2O5, γ(N2O5), were determined to be (7.2 ± 0.6) × 10(-3) (1σ) at 7% RH and (5.3 ± 0.8) × 10(-3) (1σ) at 40% RH for SiO2 particles, using the aerosol flow tube technique. We show that γ(N2O5) determined in this work can be reconciled with the two previous studies by accounting for the difference in geometric and BET derived aerosol surface areas. To probe the particle phase chemistry, individual micrometer sized SiO2 particles were optically levitated and exposed to a continuous flow of N2O5 at different RHs, and the composition of levitated particles was monitored online using Raman spectroscopy. This study represents the first investigation into the heterogeneous reactions of levitated individual SiO2 particles as a surrogate for mineral dust. Relative humidity was found to play a critical role: while no significant change of particle composition was observed by Raman spectroscopy during exposure to N2O5 at RH of <2%, increasing the RH led to the formation of nitrate species on the particle surface which could be completely removed after decreasing the RH back to <2%. This can be explained by the partitioning of HNO3 between the gas and adsorbed phases. The atmospheric implications of this work are discussed. PMID:25188692

  6. Volcanic Aerosol Radiative Properties

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew

    2015-01-01

    Large sporadic volcanic eruptions inject large amounts of sulfur bearing gases into the stratosphere which then get photochemically converted to sulfuric acid aerosol droplets that exert a radiative cooling effect on the global climate system lasting for several years.

  7. Geochemical and Isotopic Interpretations of Groundwater Flow in the Oasis Valley Flow System, Southern Nevada

    SciTech Connect

    J.M. Thomas; F.C. Benedict, Jr.; T.P. Rose; R.L. Hershey; J.B. Paces; Z.E. Peterman; I.M. Farnham; K.H. Johannesson; A.K. Singh; K.J. Stetzenbach; G.B. Hudson; J.M. Kenneally; G.F. Eaton; D.K. Smith

    2003-01-08

    This report summarizes the findings of a geochemical investigation of the Pahute Mesa-Oasis Valley groundwater flow system in southwestern Nevada. It is intended to provide geochemical data and interpretations in support of flow and contaminant transport modeling for the Western and Central Pahute Mesa Corrective Action Units.

  8. GNI - A System for the Impaction and Automated Optical Sizing of Giant Aerosol Particles with Emphasis on Sea Salt

    NASA Astrophysics Data System (ADS)

    Jensen, Jorgen

    2013-04-01

    Size distributions of giant aerosol particles (e.g. sea-salt particles, dry radius larger than 0.5 μm) are not well characterized in the atmosphere, yet they contribute greatly to both direct and indirect aerosol effects. Measurements are problematic for these particles because they (i) occur in low concentrations, (ii) have difficulty in passing through air inlets, (iii) there are problems in discriminating between dry and deliquesced particles, (iv) and impaction sampling requires labor intensive methods. In this study, a simple, high-volume impaction system called the Giant Nuclei Impactor (GNI), based on free-stream exposure of polycarbonate slides from aircraft is described, along with an automated optical microscope-based system for analysis of the impacted particles. The impaction slides are analyzed in a humidity-controlled box (typically 90% relative humidity) that allows for deliquescence of sea salt particles. A computer controlled optical microscope with two digital cameras is used to acquire and analyze images of the aerosol particles. Salt particles will form near-spherical cap solution drops at high relative humidity. The salt mass in each giant aerosol particle is then calculated using simple geometry and K ̈ohler theory by assuming a NaCl composition. The system has a sample volume of about 10 L/s at aircraft speeds of 105 m/s. For salt particles, the measurement range is from about 0.7 μm dry radius to tens of micrometers, with a size-bin resolution of 0.2 μm dry radius. The sizing accuracy was tested using glass beads of known size. Characterizing the uncertainties of observational data is critical for applications to atmospheric science studies. A comprehensive uncertainty analysis is performed for the airborne GNI manual impaction and automatic optical microscope system for sizing giant aerosol particles, with particular emphasis on sea-salt particles. The factors included are (i) sizing accuracy, (ii) concentration accuracy, (iii

  9. Ex-situ experimental studies on serpentine flow field design for redox flow battery systems

    NASA Astrophysics Data System (ADS)

    Jyothi Latha, T.; Jayanti, S.

    2014-02-01

    Electrolyte distribution using parallel flow field for redox flow battery (RFB) applications shows severe non-uniformity, while the conventional design of using the carbon felt itself as the flow distributor gives too high pressure drop. An optimized flow field design for uniform flow distribution at a minimal parasitic power loss is therefore needed for RFB systems. Since the materials and geometrical dimensions in RFBs are very different from those used in fuel cells, the hydrodynamics of the flow fields in RFBs is likely to be very different. In the present paper, we report on a fundamental study of the hydrodynamics of a serpentine flow field relevant to RFB applications. The permeability of the porous medium has been measured under different compression ratios and this is found to be in the range of 5-8 × 10-11 m2. The pressure drop in two serpentine flow fields of different geometric characteristics has been measured over a range of Reynolds numbers. Further analysis using computational fluid dynamics simulations brings out the importance of the compression of the porous medium as an additional parameter in determining the flow distribution and pressure drop in these flow fields.

  10. Novel single-phase fiber optic flow sensor system

    NASA Astrophysics Data System (ADS)

    Peng, Wei; Pickrell, Gary R.; Xu, Juncheng; Huang, Zhengyu; Kim, Dae Woong; Wang, Anbo

    2004-03-01

    In this paper, we present a novel design of a fiber optic flow sensor system for single-phase fluid flow detection. This new system is based on the principle of broadband interferometry and cantilever beam bending. The fiber optic sensor system utilizes two fiber ferrule sensors that are bonded on both sides of a cantilever beam. The flow rate can be determined by monitoring the air gap changes caused by bending of the cantilever beam. Cross-sensitivity of the temperature and pressure dependence of the sensor can be compensated for automatically. The prototype sensor system was fabricated and tested on the lab-scale with preliminary evaluations completed. Field-testing was performed in the indoor and outdoor flow loops of Tulsa University in Tulsa, Okalahoma. Both the lab-scale and field-testing results verified that the designed flow sensor system could measure the single-phase fluid flow rate with high resolution and repeatability by compensating the thermal and pressure effects of the environment. The outdoor field-testing demonstrated the feasibility of the designed fiber optic flow sensor for single-phase fluid flow rate measurements in the oil fields.

  11. Computation of subsonic flow around airfoil systems with multiple separation

    NASA Technical Reports Server (NTRS)

    Jacob, K.

    1982-01-01

    A numerical method for computing the subsonic flow around multi-element airfoil systems was developed, allowing for flow separation at one or more elements. Besides multiple rear separation also sort bubbles on the upper surface and cove bubbles can approximately be taken into account. Also, compressibility effects for pure subsonic flow are approximately accounted for. After presentation the method is applied to several examples and improved in some details. Finally, the present limitations and desirable extensions are discussed.

  12. The major species of heavy metal aerosol resulting from water cooling systems and spray dryer systems during incineration processes

    PubMed

    Wey; Yang; Wei

    1998-11-01

    Trace toxic metals in municipal solid waste may escape from the incineration process in flue gas, in dry collected ash, in wet scrubbed ash, or as a suspended aerosol. Therefore, understanding the behavior of heavy metals in the flue gas and the best controls in the air pollution control equipment are important and necessary. The control conditions of water cooling and spray dryer systems during incineration processes significantly influence the formation of heavy metal compounds. The formation of chromium (Cr), lead (Pb), and cadmium (Cd) species under various control conditions (water cooling tower and spray dryer reactor) was investigated in this study. The object of the experiment is to understand the effects of water cooling and spray dryer systems individually on the formation of heavy metal species. The operating parameters that are evaluated include different control systems, control temperatures, and chlorine content. A thermodynamic equilibrium model was also used to evaluate experimental data. In order to match real incineration conditions, a two-stage simulation was performed in this experiment. The results showed that the relationship of speciation between the simulation prediction and X-ray diffraction (XRD) analysis is consistent for Cr compounds; both indicated that Cr2O3 is the major species. The relationship is almost the same for Cd compounds, but not for Pb compounds. PMID:9846130

  13. Separating Hazardous Aerosols from Ambient Aerosols: Role of Fluorescence-Spectral Determination, Aerodynamic Deflector and Pulse Aerodynamic Localizer (PAL)

    SciTech Connect

    Pan, Yong-Le; Cobler, Patrick J.; Rhodes, Scott A.; Halverson, Justin; Chang, Richard K.

    2005-08-22

    An aerosol deflection technique based on the single-shot UV-laser-induced fluorescence spectrum from a flowing particle is presented as a possible front-end bio-aerosol/hazardous-aerosol sensor/identifier. Cued by the fluorescence spectra, individual flowing bio-aerosol particles (1-10 {micro}m in diameter) have been successfully deflected from a stream of ambient aerosols. The electronics needed to compare the fluorescence spectrum of a particular particle with that of a pre-determined fluorescence spectrum are presented in some detail. The deflected particles, with and without going through a funnel for pulse aerodynamic localization (PAL), were collected onto a substrate for further analyses. To demonstrate how hazardous materials can be deflected, TbCl{sub 3} {center_dot} 6H{sub 2}O (a simulant material for some chemical forms of Uranium Oxide) aerosol particles (2 {micro}m in diameter) mixed with Arizona road dust was separated and deflected with our system.

  14. Systems and Sensors for Debris-flow Monitoring and Warning

    PubMed Central

    Arattano, Massimo; Marchi, Lorenzo

    2008-01-01

    Debris flows are a type of mass movement that occurs in mountain torrents. They consist of a high concentration of solid material in water that flows as a wave with a steep front. Debris flows can be considered a phenomenon intermediate between landslides and water floods. They are amongst the most hazardous natural processes in mountainous regions and may occur under different climatic conditions. Their destructiveness is due to different factors: their capability of transporting and depositing huge amounts of solid materials, which may also reach large sizes (boulders of several cubic meters are commonly transported by debris flows), their steep fronts, which may reach several meters of height and also their high velocities. The implementation of both structural and non-structural control measures is often required when debris flows endanger routes, urban areas and other infrastructures. Sensor networks for debris-flow monitoring and warning play an important role amongst non-structural measures intended to reduce debris-flow risk. In particular, debris flow warning systems can be subdivided into two main classes: advance warning and event warning systems. These two classes employ different types of sensors. Advance warning systems are based on monitoring causative hydrometeorological processes (typically rainfall) and aim to issue a warning before a possible debris flow is triggered. Event warning systems are based on detecting debris flows when these processes are in progress. They have a much smaller lead time than advance warning ones but are also less prone to false alarms. Advance warning for debris flows employs sensors and techniques typical of meteorology and hydrology, including measuring rainfall by means of rain gauges and weather radar and monitoring water discharge in headwater streams. Event warning systems use different types of sensors, encompassing ultrasonic or radar gauges, ground vibration sensors, videocameras, avalanche pendulums

  15. Design flow factors for sewerage systems in small arid communities.

    PubMed

    Imam, Emad H; Elnakar, Haitham Y

    2014-09-01

    Reliable estimation of sewage flow rates is essential for the proper design of sewers, pumping stations, and treatment plants. The design of the various components of the sewerage system should be based on the most critical flow rates with a focus on extremely low and peak flow rates that would be sustained for a duration related to the acceptable limits of behavior of the components under consideration. The extreme flow conditions and to what extent they differ from the average values are closely related to the size of the community or network, and the socioeconomic conditions. A single pumping station is usually sufficient to pump flow from small community in either flat or non-undulating topography. Therefore, the hydraulic loading on the wastewater treatment plant (WWTP) results from the pumped flow from the pumping station rather than the trunk sewer flow. The intermittent operation of the pumping units further accentuates the sewage hydrograph in the final trunk sewer. Accordingly, the design flow for the various components of the WWTP should be determined based on their relevant flow factors. In this study, analysis of one representative small community out of five monitored small communities in Egypt and the Kingdom of Saudi Arabia is presented. Pumped sewage flow rates were measured and the sewer incoming flows were hydraulically derived. The hourly and daily sewer and pumped flow records were analyzed to derive the relationship between the flow factors that would be sustained for various durations (instantaneously, 1 h, 2 h, etc.) and their probability of non-exceedance. The resulting peaking factors with a consideration for their sustained flow duration and specified probability would permit the design of the various components of the treatment plant using more accurate critical flows. PMID:25685521

  16. Flow and heat transfer in rotating-disc systems. Volume I - Rotor-stator systems

    NASA Astrophysics Data System (ADS)

    Owen, J. M.; Roger, R. H.

    The rotating flows occurring inside turbomachinery are discussed. Laminar and turbulent flow over a single disk and heat transfer from a single disk are addressed. Rotor-stator systems with and without superposed flow, heat transfer in rotor-stator systems, and the ingress problem of sealing rotor-stator systems are examined.

  17. Pulsed photoacoustic flow imaging with a handheld system

    NASA Astrophysics Data System (ADS)

    van den Berg, Pim J.; Daoudi, Khalid; Steenbergen, Wiendelt

    2016-02-01

    Flow imaging is an important technique in a range of disease areas, but estimating low flow speeds, especially near the walls of blood vessels, remains challenging. Pulsed photoacoustic flow imaging can be an alternative since there is little signal contamination from background tissue with photoacoustic imaging. We propose flow imaging using a clinical photoacoustic system that is both handheld and portable. The system integrates a linear array with 7.5 MHz central frequency in combination with a high-repetition-rate diode laser to allow high-speed photoacoustic imaging-ideal for this application. This work shows the flow imaging performance of the system in vitro using microparticles. Both two-dimensional (2-D) flow images and quantitative flow velocities from 12 to 75 mm/s were obtained. In a transparent bulk medium, flow estimation showed standard errors of ˜7% the estimated speed; in the presence of tissue-realistic optical scattering, the error increased to 40% due to limited signal-to-noise ratio. In the future, photoacoustic flow imaging can potentially be performed in vivo using fluorophore-filled vesicles or with an improved setup on whole blood.

  18. THE CONTINUOUS FLOW ANALYZER AUTOMATION SYSTEM. PART III -- PROGRAM DOCUMENTATION

    EPA Science Inventory

    This report contains complete documentation for the 21 programs and eight data files of the EPA Continuous Flow Analyzer Automation System. This system can receive lists of samples from the Sample File Control System and return the measured concentrations to that system. It is ca...

  19. Modelling of uncertainness for a flow and level system

    NASA Astrophysics Data System (ADS)

    Hernández, C.; Angel, L.; Viola, J.

    2016-07-01

    This paper presents the identification of uncertainness that affects the dynamics of a flow and level system. Initially, flow a level system is descripted. Then, family of plants is determined from the identification of dynamic model for different operating conditions. The uncertain model reflects the changes for different operating conditions when the output flow and storage tank dimensions are varied. Finally, the maximum multiplicative uncertain is calculated to define the desired controller specifications to achieve a robust stability and performance of the closed loop system.

  20. Effect of aerosol variation on radiance in the earth's atmosphere-ocean system.

    NASA Technical Reports Server (NTRS)

    Plass, G. N.; Kattawar, G. W.

    1972-01-01

    Calculation of the radiance at the top and bottom of the atmosphere with a realistic model of both the atmosphere and ocean. It is found that the upward flux at the top of the atmosphere, as well as the angular distribution of the radiation, changes appreciably as the aerosol amount increases from normal to ten times normal. At the same time, the upward and downward radiance just above the ocean surface undergoes important changes. The radiance does not change appreciably with variations in the aerosol distribution with height so long as the total aerosol amount remains constant. Similarly, changes in the ozone amount cause only small changes in the radiance at the wavelengths considered (0.7, 0.9, and 1.67 micron). Very little radiation returns to the atmosphere from the ocean at 0.9 and 1.67 micron because of the high absorption of water at these wavelengths.

  1. Circulation system for flowing uranium hexafluoride cavity reactor experiments

    NASA Technical Reports Server (NTRS)

    Jaminet, J. F.; Kendall, J. S.

    1976-01-01

    Research related to determining the feasibility of producing continuous power from fissile fuel in the gaseous state is presented. The development of three laboratory-scale flow systems for handling gaseous UF6 at temperatures up to 500 K, pressure up to approximately 40 atm, and continuous flow rates up to approximately 50g/s is presented. A UF6 handling system fabricated for static critical tests currently being conducted is described. The system was designed to supply UF6 to a double-walled aluminum core canister assembly at temperatures between 300 K and 400 K and pressure up to 4 atm. A second UF6 handling system designed to provide a circulating flow of up to 50g/s of gaseous UF6 in a closed-loop through a double-walled aluminum core canister with controlled temperature and pressure is described. Data from flow tests using UF6 and UF6/He mixtures with this system at flow rates up to approximately 12g/s and pressure up to 4 atm are presented. A third UF6 handling system fabricated to provide a continuous flow of UF6 at flow rates up to 5g/s and at pressures up to 40 atm for use in rf-heated, uranium plasma confinement experiments is described.

  2. PARALLEL EVALUATION OF CONSTANT AND DIURNAL FLOW TREATMENT SYSTEMS

    EPA Science Inventory

    Pilot plant studies were performed to evaluate the effects of an imposed diurnal flow pattern on a conventional activated sludge treatment plant. These results were compared against data generated on a similar system treating a constant flow. Effects on primary clarifier and fina...

  3. System proportions fluid-flow in response to demand signals

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Control system provides proportioned fluid flow rates in response to demand signals. It compares a digital signal, representing a flow demand, with a reference signal to yield a control voltage to one or more solenoid valves connected to orifices of a predetermined size.

  4. NHEXAS PHASE I REGION 5 STUDY--STANDARD OPERATING PROCEDURE--PERSONAL, INDOOR AND OUTDOOR AIR SAMPLING PROCEDURES FOR TOTAL INSPIRABLE AND PM10 AEROSOLS (RTI/ACS-AP-209-010)

    EPA Science Inventory

    This protocol describes the procedures for field application of personal, indoor, and outdoor air sampling systems to collect integrated aerosol samples using a battery operated personal sampling system (pump, flow controller, Delta Pressure sensor, thermistor, interval timer, da...

  5. Application of a global nonhydrostatic model with a stretched-grid system to regional aerosol simulations around Japan

    NASA Astrophysics Data System (ADS)

    Goto, D.; Dai, T.; Satoh, M.; Tomita, H.; Uchida, J.; Misawa, S.; Inoue, T.; Tsuruta, H.; Ueda, K.; Ng, C. F. S.; Takami, A.; Sugimoto, N.; Shimizu, A.; Ohara, T.; Nakajima, T.

    2014-01-01

    An aerosol-coupled global nonhydrostatic model with a stretched-grid system has been developed. Circulations over the global and target domains are simulated with a single model, which includes fine meshes covering the target region to calculate meso-scale circulations. The stretched global model involves relatively low computational costs to simulate atmospheric aerosols with fine horizontal resolutions compared with a global uniform nonhydrostatic model. As opposed to general regional models, neither a nesting technique nor boundary conditions are required. In this study, we developed a new air-quality model for the simulation of areas surrounding Tokyo, Japan, with a maximum horizontal resolution of approximately 10 km. We determined that this model was capable of simulating meteorological fields and anthropogenic primary particles, e.g., elemental carbon, and secondary particles, such as sulfate, with comparable results to those found with in-situ measurements and with other regional models. By combining the meteorological fields obtained from an atmosphere-ocean coupled model, we also applied the new model to a climate scenario experiment of PM2.5 (aerosol particles with diameters less than 2.5 μm) over Japan with a high horizontal resolution to assess the public health impact at the prefecture scale.

  6. Analysis for chemical characterization of atmospheric aerosols application of X-ray microprobe system and double thin film method.

    PubMed

    Tohno, Susumu; Ma, Chang-Jin; Hayakawa, Shinjiro; Yamasaki, Satoshi; Kasahara, Mikio

    2006-09-01

    The X-ray microprobe system was applied to ultra trace characterization of single Kosa aerosols and non-Kosa aerosols simultaneously collected at Yasaka, Japan and TaeAnn, Korea. We demonstrated remarkable mass increase of heavy metals as well as soil components in individual particles during the Kosa event compared with the non-Kosa period at Yasaka. Backward trajectory analysis suggested that the Kosa samples were in the mixing state of mineral components and anthropogenic heavy elements. Double thin film method was applied to investigate the seasonal change of the mixing states of single sea-salt aerosols associated with chlorine loss due to the heterogeneous reactions between sea-salt particles and acidic gases. It was revealed that the percentages of both chloride-nitrate mixed particles and sulfate-nitrate ones were larger in wintertime than those in summertime and fraction of chloride-nitrate mixed particles increased with an increase of particle size. Comparison between the size-segregated bulk analysis and the single particle analysis demonstrated that remarkable chloride depletion occurred in coarse particles sampled on May in the former analysis, while chloride depletion in coarse particles was not marked in the latter analysis. The discrepancy attributes to the difference of the sampling time between both analyses because significant change of air mass route occurred during the bulk sampling after completion of the single particle sampling. PMID:16741794

  7. Guide to Flow Measurement for Electric Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Frieman, Jason D.; Walker, Mitchell L. R.; Snyder, Steve

    2013-01-01

    In electric propulsion (EP) systems, accurate measurement of the propellant mass flow rate of gas or liquid to the thruster and external cathode is a key input in the calculation of thruster efficiency and specific impulse. Although such measurements are often achieved with commercial mass flow controllers and meters integrated into propellant feed systems, the variability in potential propellant options and flow requirements amongst the spectrum of EP power regimes and devices complicates meter selection, integration, and operation. At the direction of the Committee on Standards for Electric Propulsion Testing, a guide was jointly developed by members of the electric propulsion community to establish a unified document that contains the working principles, methods of implementation and analysis, and calibration techniques and recommendations on the use of mass flow meters in laboratory and spacecraft electric propulsion systems. The guide is applicable to EP devices of all types and power levels ranging from microthrusters to high-power ion engines and Hall effect thrusters. The establishment of a community standard on mass flow metering will help ensure the selection of the proper meter for each application. It will also improve the quality of system performance estimates by providing comprehensive information on the physical phenomena and systematic errors that must be accounted for during the analysis of flow measurement data. This paper will outline the standard methods and recommended practices described in the guide titled "Flow Measurement for Electric Propulsion Systems."

  8. Boundary-layer-ingesting inlet flow control system

    NASA Technical Reports Server (NTRS)

    Owens, Lewis R. (Inventor); Allan, Brian G. (Inventor)

    2010-01-01

    A system for reducing distortion at the aerodynamic interface plane of a boundary-layer-ingesting inlet using a combination of active and passive flow control devices is disclosed. Active flow control jets and vortex generating vanes are used in combination to reduce distortion across a range of inlet operating conditions. Together, the vortex generating vanes can reduce most of the inlet distortion and the active flow control jets can be used at a significantly reduced control jet mass flow rate to make sure the inlet distortion stays low as the inlet mass flow rate varies. Overall inlet distortion, measured and described as average SAE circumferential distortion descriptor, was maintained at a value of 0.02 or less. Advantageous arrangements and orientations of the active flow control jets and the vortex generating vanes were developed using computational fluid dynamics simulations and wind tunnel experimentations.

  9. Energy flow for electric power system deregulation

    NASA Astrophysics Data System (ADS)

    Lin, Chia-Hung

    Over the past few years, the electric power utility industry in North America and other countries has experienced a strong drive towards deregulation. People have considered the necessity of deregulation of electric utilities for higher energy efficiency and energy saving. The vertically integrated monopolistic industry is being transferred into a horizontally integrated competitive structure in some countries. Wheeling charges are a current high priority problem throughout the power industry, for independent power producers, as well as regulators. Nevertheless the present transmission pricing mechanism fails to be adjusted by a customer loading condition. Customer loading is dynamic, but the present wheeling charge method is fixed, not real-time. A real-time wheeling charge method is developed in this dissertation. This dissertation introduces a concept of a power flow network which can be used for the calculation of power contribution factors in a network. The contribution factor is defined as the ratio of the power contributed by a particular source to a line flow or bus load to the total output of the source. Generation, transmission, and distribution companies can employ contribution factors for the calculation of energy cost, wheeling charges, and loss compensation. Based on the concept of contribution factors, a proposed loss allocation method is developed in this dissertation. Besides, counterflow condition will be given a credit in the proposed loss allocation method. A simple 22-bus example was used for evaluating the contribution factors, proposed wheeling charge method, and loss allocation method.

  10. The Redox Flow System for solar photovoltaic energy storage

    NASA Technical Reports Server (NTRS)

    Odonnell, P.; Gahn, R. F.; Pfeiffer, W.

    1976-01-01

    The interfacing of a Solar Photovoltaic System and a Redox Flow System for storage was workable. The Redox Flow System, which utilizes the oxidation-reduction capability of two redox couples, in this case iron and titanium, for its storage capacity, gave a relatively constant output regardless of solar activity so that a load could be run continually day and night utilizing the sun's energy. One portion of the system was connected to a bank of solar cells to electrochemically charge the solutions, while a separate part of the system was used to electrochemically discharge the stored energy.

  11. Developing a model system for studying the ozone processing of atmospheric aerosols by following changes in surface properties

    NASA Astrophysics Data System (ADS)

    Gonzalez-Labrada, Erick

    Atmospheric aerosols have a significant organic composition as determined by field measurement studies. This organic material is released to the atmosphere from both natural and anthropogenic sources, such as wind bursting of the ocean surface, car exhausts, and meat cooking, among others. An inverted micelle model has been proposed in order to explain the high concentration of organic compounds in aerosol particles. The model describes an organic film coating the air-liquid interface of an aqueous aerosol core. Chemical processing of this organic film by atmospheric oxidants (such as OH radicals, O3, and NO3) through heterogeneous and multiphase reactions can activate the aerosol to participate in atmospheric chemistry. After reaction, the particle has an increased role in the absorption and scattering of incoming solar radiation and cloud formation. Another consequence of this oxidation is the decrease of the atmospheric budget of gas-phase trace species, as well as the formation of volatile products. Several studies have proposed that the ozonolysis of organic films in aerosols takes place mainly at the surface. Therefore, the objective of this research was to develop a suitable model system for following the reaction through quantitative changes of a property inherent to the surface. Several attempts were made to examine the ozonolysis of organic monolayers at either solid or liquid surfaces. The studied monolayers contained unsaturated organic compounds as the only component or as part of a binary mixture with saturated compounds. The study of the ozone processing of monolayers deposited on solid substrates revealed information about changes in the hydrophobic character of the surface that occurred because of the reaction. On the other hand, the processing of a monolayer spread on a pendant drop allowed a real-time monitoring of surface pressure changes. This permitted a kinetic study of the reaction that yielded parameters related exclusively to processes

  12. MULTICOMPONENT AEROSOL DYNAMICS OF THE PB-O2 SYSTEM IN A BENCH SCALE FLAME INCINERATOR

    EPA Science Inventory

    A study was carried out to understand the formation and growth of lead particles in a flame incinerator. A bench scale flame incinerator was used to perform controlled experiments with lead acetate as a test compound. A dilution probe in conjunction with real-time aerosol instrum...

  13. NOAA-USGS Debris-Flow Warning System - Final Report

    USGS Publications Warehouse

    NOAA-USGS Debris Flow Task Force

    2005-01-01

    Landslides and debris flows cause loss of life and millions of dollars in property damage annually in the United States (National Research Council, 2004). In an effort to reduce loss of life by debris flows, the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) and the U.S. Geological Survey (USGS) operated an experimental debris-flow prediction and warning system in the San Francisco Bay area from 1986 to 1995 that relied on forecasts and measurements of precipitation linked to empirical precipitation thresholds to predict the onset of rainfall-triggered debris flows. Since 1995, there have been substantial improvements in quantifying precipitation estimates and forecasts, development of better models for delineating landslide hazards, and advancements in geographic information technology that allow stronger spatial and temporal linkage between precipitation forecasts and hazard models. Unfortunately, there have also been several debris flows that have caused loss of life and property across the United States. Establishment of debris-flow warning systems in areas where linkages between rainfall amounts and debris-flow occurrence have been identified can help mitigate the hazards posed by these types of landslides. Development of a national warning system can help support the NOAA-USGS goal of issuing timely Warnings of potential debris flows to the affected populace and civil authorities on a broader scale. This document presents the findings and recommendations of a joint NOAA-USGS Task Force that assessed the current state-of-the-art in precipitation forecasting and debris-flow hazard-assessment techniques. This report includes an assessment of the science and resources needed to establish a demonstration debris-flow warning project in recently burned areas of southern California and the necessary scientific advancements and resources associated with expanding such a warning system to unburned areas and, possibly, to a

  14. Laminar Flow Control Leading Edge Systems in Simulated Airline Service

    NASA Technical Reports Server (NTRS)

    Wagner, R. D.; Maddalon, D. V.; Fisher, D. F.

    1988-01-01

    Achieving laminar flow on the wings of a commercial transport involves difficult problems associated with the wing leading edge. The NASA Leading Edge Flight Test Program has made major progress toward the solution of these problems. The effectiveness and practicality of candidate laminar flow leading edge systems were proven under representative airline service conditions. This was accomplished in a series of simulated airline service flights by modifying a JetStar aircraft with laminar flow leading edge systems and operating it out of three commercial airports in the United States. The aircraft was operated as an airliner would under actual air traffic conditions, in bad weather, and in insect infested environments.

  15. Low power, constant-flow air pump systems

    SciTech Connect

    Polito, M.D.; Albert, B.

    1994-01-01

    A rugged, yet small and lightweight constant-flow air pump system has been designed. Flow control is achieved using a novel approach which is three times more power efficient than previous designs. The resultant savings in battery size and weight makes these pumps ideal for sampling air on balloon platforms. The pump package includes meteorological sensors and an onboard computer that stores time and sensor data and turns the constant-flow pump circuit on/off. Some applications of these systems are also presented in this report.

  16. Validation and verification of expert systems using evidence flow graphs

    NASA Technical Reports Server (NTRS)

    Becker, Lee A.; Green, Peter E.; Duckworth, R. James; Bhatnagar, Jayant

    1989-01-01

    This paper describes an ongoing investigation into the use of evidence flow graph techniques for performing V&V of expert systems. This method involves translating a rule-base into an evidence flow graph, a representation originally developed for real-time intelligent systems in distributed environments, and then running simulations of the evidence flow graph. Certain errors can be found during the translation process. The simulations can detect output sensitivity to rule firing order, to order of presentation of inputs, and to small changes in input values.

  17. Synchronization trigger control system for flow visualization

    NASA Technical Reports Server (NTRS)

    Chun, K. S.

    1987-01-01

    The use of cinematography or holographic interferometry for dynamic flow visualization in an internal combustion engine requires a control device that globally synchronizes camera and light source timing at a predefined shaft encoder angle. The device is capable of 0.35 deg resolution for rotational speeds of up to 73 240 rpm. This was achieved by implementing the shaft encoder signal addressed look-up table (LUT) and appropriate latches. The developed digital signal processing technique achieves 25 nsec of high speed triggering angle detection by using direct parallel bit comparison of the shaft encoder digital code with a simulated angle reference code, instead of using angle value comparison which involves more complicated computation steps. In order to establish synchronization to an AC reference signal whose magnitude is variant with the rotating speed, a dynamic peak followup synchronization technique has been devised. This method scrutinizes the reference signal and provides the right timing within 40 nsec. Two application examples are described.

  18. A bulk flow model of a brush seal system

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Schlumberger, S.; Braun, M. J.; Choy, F.; Mullen, R. L.

    1991-01-01

    Fibers can be readily fabricated into a variety of seal configurations that are compliant and responsive to high speed or lightly loaded systems. A linear, circular, or contoured brush seal system is a contact seal consisting of the bristle pattern and hardened interface. When compared to a labyrinth seal, the brush seal system is superior and features low leakage, dynamic stability, and permits compliant structures. But in turn, the system usually requires a hardened smooth interface and permits only limited pressure drops. Wear life and wear debris for operations with static or dynamic excitation are largely undetermined. A seal system involves control of fluid within specific boundaries. The brush and rub ring (or rub surface) form a seal system. Design similitudes, a bulk flow model, and rub ring (interface) coatings are discussed. The bulk flow model calculations are based on flows in porous media and filters. The coatings work is based on experience and expanded to include current practice.

  19. Parallel flow diffusion battery

    DOEpatents

    Yeh, H.C.; Cheng, Y.S.

    1984-01-01

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  20. Parallel flow diffusion battery

    DOEpatents

    Yeh, Hsu-Chi; Cheng, Yung-Sung

    1984-08-07

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  1. Use of acoustic monitoring system for debris flow discharge evaluation

    NASA Astrophysics Data System (ADS)

    Galgaro, A. G.; Tecca, P. R.; Genevois, R.; Deganutti, A. M.

    2003-04-01

    In 1997 an automated system for monitoring of debris flows has been installed in the Acquabona channel Dolomites, Italy. Induction geophones, with a specific frequency of 10 Hz, measure the amplitude of vertical ground vibrations generated by the passage of a flowing mass along the channel. Continuous acoustic logs and ultrasonic hydrograph recorded at the lower-channel measurement station for the debris flow of August 17, 1998, show a striking correspondence. This correspondence, already observed in different flow sites, is represented by the best fit between flow depth and flow sensor amplitude. Average front velocity for surges, calculated from the signal peak time shift and the distance between the sensors along the flow path, range between 2.00 and 7.7 m/s. As the ultrasonic sensor provides a way to measure the variation of the flow section area with the flow depth, the debris flow peak discharge may be estimated; obtained values of debris flow peak discharge range from 4 and 30 m3/s. Volumes were calculated by integrating instantaneous discharges through the hydrograph and by integrating the geophone log (acoustic flux). Volumes of 13700 m3 and 15500 m3 have been respectively obtained. The slight difference between the two values may result from the fact that acoustic records: i) are sensitive to the high frequencies, typical of the debris flow tails; ii) sum up the contributions sent by the whole flowing mass, while the ecometer detect the flow depth at every time at only one section. As a consequence the rising of the whole geophone log gives a higher value at the integration result. This only acoustic system can give a reasonably proxy for discharge and total volumes involved, which are among the most important parameters for debris flow hazard assessment and planning countermeasures. This methodology can be used in other debris flow sites if they are calibrated by the acoustic characterization of debris, obtained by both seismic surveys and SPT tests, and

  2. Fluid flow systems analysis to save energy

    SciTech Connect

    Parekh, P.S.

    1999-07-01

    Industrial processes use rotating equipment (e.g.; pump, fan, blower, centrifugal compressor, positive displacement compressor) and pipe (or duct) to move fluid from point A to B, with many processes using electric motors as the prime mover. Most of the systems in the industry are over-designed to meet a peak load demand which might occur over a small fraction of the time or to satisfy a higher pressure demanded by a much smaller user in the same process. The system over-design will result in a selection of larger but inefficient rotating equipment and electric motor system. A careful life cycle cost and economic evaluation must be undertaken to ensure that the process audit, reengineering and equipment selections are not impacting the industrial process goals, but result in a least optimal cost over the life of the project. The paper will define, discuss, and present various process systems in chemical, hydrocarbon and pulp and paper industries. It will discuss the interactive impact of the changes in the mechanical system configuration and the changes in the process variables to better redesign the system and reduce the cost of operation. it will also present a check list of energy conservation measures (ECM) or opportunities. Such ECMs will be related to hydraulics, system components, process modifications, and system efficiency. Two or three case studies will be presented focusing on various conservation measures that improve electrical operating efficiency of a distillation column system. An incremental cost and payback analysis will be presented to assist the investment in process optimization and energy savings' measures.

  3. Permafrost thaw in a nested groundwater-flow system

    USGS Publications Warehouse

    McKenzie, Jeffery M.; Voss, Clifford I.

    2013-01-01

    Groundwater flow in cold regions containing permafrost accelerates climate-warming-driven thaw and changes thaw patterns. Simulation analyses of groundwater flow and heat transport with freeze/thaw in typical cold-regions terrain with nested flow indicate that early thaw rate is particularly enhanced by flow, the time when adverse environmental impacts of climate-warming-induced permafrost loss may be severest. For the slowest climate-warming rate predicted by the Intergovernmental Panel on Climate Change (IPCC), once significant groundwater flow begins, thick permafrost layers can vanish in several hundred years, but survive over 1,000 years where flow is minimal. Large-scale thaw depends mostly on the balance of heat advection and conduction in the supra-permafrost zone. Surface-water bodies underlain by open taliks allow slow sub-permafrost flow, with lesser influence on regional thaw. Advection dominance over conduction depends on permeability and topography. Groundwater flow around permafrost and flow through permafrost impact thaw differently; the latter enhances early thaw rate. Air-temperature seasonality also increases early thaw. Hydrogeologic heterogeneity and topography strongly affect thaw rates/patterns. Permafrost controls the groundwater/surface-water-geomorphology system; hence, prediction and mitigation of impacts of thaw on ecology, chemical exports and infrastructure require improved hydrogeology/permafrost characterization and understanding

  4. Nested subcritical flows within supercritical systems

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Braun, M. J.; Wheeler, R. L., III; Mullen, R. L.

    1985-01-01

    In supercritical systems the design inlet and outlet pressures are maintained above the thermaodynamic critical pressure P sub C. Designers rely on this simple rule of thumb to circumvent problems associated with a subcritical pressure regime nested within the supercritical pressure system along with the uncertainties in heat transfer, fluid mechanics, and thermophysical property variations. The simple rule of thumb is adequate in many low-power designs but is inadequate for high-performance turbomachines and linear systems, where nested two-phase regions can exist. Examples for a free-jet expansion with backpressure greater than P sub C and a rotor (bearing) with ambient pressure greater than P sub C illustrate the existence of subcritical pressure regimes nested within supercritical systems.

  5. The direct effect of aerosols on the radiation budget and climate of the Earth-atmosphere system: its variability in space and time

    NASA Astrophysics Data System (ADS)

    Hatzianastassiou, N.

    2009-04-01

    Atmospheric aerosols, these tiny particles suspended in the air, play a very important role for the Earth-atmosphere climate system on both global and regional scales through various mechanisms and physical processes. The climatic effects of aerosols are determined by modifications they induce on the various components of the Earth's radiation budget. Despite the progress that has been made lately, there is still much to learn about the climatic role of aerosols in various aspects. One of the most important issues that has to be addressed is the spatial and temporal variability, especially the temporal variability of aerosol properties and their consequent radiative effects. For example, there is uncertainty with regard to aerosol radiative properties and whether or not aerosol loads are increasing or decreasing with time, and what the consequences are. Moreover, the extent to which aerosols cool or warm the planet is not clear, as well as the contribution to this cooling/warming by aerosols of natural and anthropogenic origin. Given that the aerosol radiative effects, especially on radiation reaching the Earth's surface and in the atmosphere, cannot be directly measured/observed, models are necessary to overcome this problem. Specifically, radiative transfer models (RTMs) are able to calculate the radiation fluxes within the entire Earth-atmosphere system from regional to planetary scale, and the flux changes caused by aerosols. Yet, what is more interesting for models is that they allow us to study in detail the space and time resolved aerosol radiative effects and their sensitivity to various physical parameters. Using RTMs the aerosol direct effect on solar radiation can be determined at the top of the atmosphere (DRETOA) in the atmosphere (DREatm) and at the Earth's surface (DREsurf). Using a detailed radiative transfer model together with climatological input data for surface and atmospheric variables, the direct radiative effects of aerosols (DREs) were

  6. Interplay of Proximal Flow Confluence and Distal Flow Divergence in Patient-Specific Vertebrobasilar System

    PubMed Central

    Yin, Xiaoping; Huang, Xu; Feng, Yundi; Tan, Wenchang; Liu, Huaijun

    2016-01-01

    Approximately one-quarter of ischemic strokes involve the vertebrobasilar arterial system that includes the upstream flow confluence and downstream flow divergence. A patient-specific hemodynamic analysis is needed to understand the posterior circulation. The objective of this study is to determine the distribution of hemodynamic parameters in the vertebrobasilar system, based on computer tomography angiography images. Here, the interplay of upstream flow confluence and downstream flow divergence was hypothesized to be a determinant factor for the hemodynamic distribution in the vertebrobasilar system. A computational fluid dynamics model was used to compute the flow fields in patient-specific vertebrobasilar models (n = 6). The inlet and outlet boundary conditions were the aortic pressure waveform and flow resistances, respectively. A 50% reduction of total outlet area was found to induce a ten-fold increase in surface area ratio of low time-averaged wall shear stress (i.e., TAWSS ≤ 4 dynes/cm2). This study enhances our understanding of the posterior circulation associated with the incidence of atherosclerotic plaques. PMID:27467755

  7. Interplay of Proximal Flow Confluence and Distal Flow Divergence in Patient-Specific Vertebrobasilar System.

    PubMed

    Yin, Xiaoping; Huang, Xu; Feng, Yundi; Tan, Wenchang; Liu, Huaijun; Huo, Yunlong

    2016-01-01

    Approximately one-quarter of ischemic strokes involve the vertebrobasilar arterial system that includes the upstream flow confluence and downstream flow divergence. A patient-specific hemodynamic analysis is needed to understand the posterior circulation. The objective of this study is to determine the distribution of hemodynamic parameters in the vertebrobasilar system, based on computer tomography angiography images. Here, the interplay of upstream flow confluence and downstream flow divergence was hypothesized to be a determinant factor for the hemodynamic distribution in the vertebrobasilar system. A computational fluid dynamics model was used to compute the flow fields in patient-specific vertebrobasilar models (n = 6). The inlet and outlet boundary conditions were the aortic pressure waveform and flow resistances, respectively. A 50% reduction of total outlet area was found to induce a ten-fold increase in surface area ratio of low time-averaged wall shear stress (i.e., TAWSS ≤ 4 dynes/cm2). This study enhances our understanding of the posterior circulation associated with the incidence of atherosclerotic plaques. PMID:27467755

  8. Field and Laboratory Studies of Atmospheric Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Coggon, Matthew Mitchell

    these conditions to all measurements conducted during E-PEACE demonstrated that a large fraction of cloud droplet (72%) and dry aerosol mass (12%) sampled in the California coastal study region was heavily or moderately influenced by ship emissions. Another study investigated the chemical and physical evolution of a controlled organic plume emitted from the R/V Point Sur. Under sunny conditions, nucleated particles composed of oxidized organic compounds contributed nearly an order of magnitude more cloud condensation nuclei (CCN) than less oxidized particles formed under cloudy conditions. The processing time necessary for particles to become CCN active was short ( 4 hr). Laboratory chamber experiments were also conducted to evaluate particle-phase processes influencing aerosol phase and composition. In one study, ammonium sulfate seed was coated with a layer of secondary organic aerosol (SOA) from toluene oxidation followed by a layer of SOA from α-pinene oxidation. The system exhibited different evaporative properties than ammonium sulfate seed initially coated with α-pinene SOA followed by a layer of toluene SOA. This behavior is consistent with a shell-and-core model and suggests limited mixing among different SOA types. Another study investigated the reactive uptake of isoprene epoxy diols (IEPOX) onto non-acidified aerosol. It was demonstrated that particle acidity has limited influence on organic aerosol formation onto ammonium sulfate seed, and that the chemical system is limited by the availability of nucleophiles such as sulfate. Flow tube experiments were conducted to examine the role of iron in the reactive uptake and chemical oxidation of glycolaldehyde. Aerosol particles doped with iron and hydrogen peroxide were mixed with gas-phase glycolaldehyde and photochemically aged in a custom-built flow reactor. Compared to particles free of iron, iron-doped aerosols significantly enhanced the oxygen to carbon (O/C) ratio of accumulated organic mass. The primary

  9. Structural integrated sensor and actuator systems for active flow control

    NASA Astrophysics Data System (ADS)

    Behr, Christian; Schwerter, Martin; Leester-Schädel, Monika; Wierach, Peter; Dietzel, Andreas; Sinapius, Michael

    2016-04-01

    An adaptive flow separation control system is designed and implemented as an essential part of a novel high-lift device for future aircraft. The system consists of MEMS pressure sensors to determine the flow conditions and adaptive lips to regulate the mass flow and the velocity of a wall near stream over the internally blown Coanda flap. By the oscillating lip the mass flow in the blowing slot changes dynamically, consequently the momentum exchange of the boundary layer over a high lift flap required mass flow can be reduced. These new compact and highly integrated systems provide a real-time monitoring and manipulation of the flow conditions. In this context the integration of pressure sensors into flow sensing airfoils of composite material is investigated. Mechanical and electrical properties of the integrated sensors are investigated under mechanical loads during tensile tests. The sensors contain a reference pressure chamber isolated to the ambient by a deformable membrane with integrated piezoresistors connected as a Wheatstone bridge, which outputs voltage signals depending on the ambient pressure. The composite material in which the sensors are embedded consists of 22 individual layers of unidirectional glass fiber reinforced plastic (GFRP) prepreg. The results of the experiments are used for adapting the design of the sensors and the layout of the laminate to ensure an optimized flux of force in highly loaded structures primarily for future aeronautical applications. It can be shown that the pressure sensor withstands the embedding process into fiber composites with full functional capability and predictable behavior under stress.

  10. Impacts of increasing the aerosol complexity in the Met Office global numerical weather prediction model

    NASA Astrophysics Data System (ADS)

    Mulcahy, J. P.; Walters, D. N.; Bellouin, N.; Milton, S. F.

    2014-05-01

    The inclusion of the direct and indirect radiative effects of aerosols in high-resolution global numerical weather prediction (NWP) models is being increasingly recognised as important for the improved accuracy of short-range weather forecasts. In this study the impacts of increasing the aerosol complexity in the global NWP configuration of the Met Office Unified Model (MetUM) are investigated. A hierarchy of aerosol representations are evaluated including three-dimensional monthly mean speciated aerosol climatologies, fully prognostic aerosols modelled using the CLASSIC aerosol scheme and finally, initialised aerosols using assimilated aerosol fields from the GEMS project. The prognostic aerosol schemes are better able to predict the temporal and spatial variation of atmospheric aerosol optical depth, which is particularly important in cases of large sporadic aerosol events such as large dust storms or forest fires. Including the direct effect of aerosols improves model biases in outgoing long-wave radiation over West Africa due to a better representation of dust. However, uncertainties in dust optical properties propagate to its direct effect and the subsequent model response. Inclusion of the indirect aerosol effects improves surface radiation biases at the North Slope of Alaska ARM site due to lower cloud amounts in high-latitude clean-air regions. This leads to improved temperature and height forecasts in this region. Impacts on the global mean model precipitation and large-scale circulation fields were found to be generally small in the short-range forecasts. However, the indirect aerosol effect leads to a strengthening of the low-level monsoon flow over the Arabian Sea and Bay of Bengal and an increase in precipitation over Southeast Asia. Regional impacts on the African Easterly Jet (AEJ) are also presented with the large dust loading in the aerosol climatology enhancing of the heat low over West Africa and weakening the AEJ. This study highlights the

  11. Impacts of increasing the aerosol complexity in the Met Office global NWP model

    NASA Astrophysics Data System (ADS)

    Mulcahy, J. P.; Walters, D. N.; Bellouin, N.; Milton, S. F.

    2013-11-01

    Inclusion of the direct and indirect radiative effects of aerosols in high resolution global numerical weather prediction (NWP) models is being increasingly recognised as important for the improved accuracy of short-range weather forecasts. In this study the impacts of increasing the aerosol complexity in the global NWP configuration of the Met Office Unified Model (MetUM) are investigated. A hierarchy of aerosol representations are evaluated including three dimensional monthly mean speciated aerosol climatologies, fully prognostic aerosols modelled using the CLASSIC aerosol scheme and finally, initialised aerosols using assimilated aerosol fields from the GEMS project. The prognostic aerosol schemes are better able to predict the temporal and spatial variation of atmospheric aerosol optical depth, which is particularly important in cases of large sporadic aerosol events such as large dust storms or forest fires. Including the direct effect of aerosols improves model biases in outgoing longwave radiation over West Africa due to a better representation of dust. However, uncertainties in dust optical properties propogate to its direct effect and the subsequent model response. Inclusion of the indirect aerosol effects improves surface radiation biases at the North Slope of Alaska ARM site due to lower cloud amounts in high latitude clean air regions. This leads to improved temperature and height forecasts in this region. Impacts on the global mean model precipitation and large-scale circulation fields were found to be generally small in the short range forecasts. However, the indirect aerosol effect leads to a strengthening of the low level monsoon flow over the Arabian Sea and Bay of Bengal and an increase in precipitation over Southeast Asia. Regional impacts on the African Easterly Jet (AEJ) are also presented with the large dust loading in the aerosol climatology enhancing of the heat low over West Africa and weakening the AEJ. This study highlights the importance

  12. Mean Line Pump Flow Model in Rocket Engine System Simulation

    NASA Technical Reports Server (NTRS)

    Veres, Joseph P.; Lavelle, Thomas M.

    2000-01-01

    A mean line pump flow modeling method has been developed to provide a fast capability for modeling turbopumps of rocket engines. Based on this method, a mean line pump flow code PUMPA has been written that can predict the performance of pumps at off-design operating conditions, given the loss of the diffusion system at the design point. The pump code can model axial flow inducers, mixed-flow and centrifugal pumps. The code can model multistage pumps in series. The code features rapid input setup and computer run time, and is an effective analysis and conceptual design tool. The map generation capability of the code provides the map information needed for interfacing with a rocket engine system modeling code. The off-design and multistage modeling capabilities of the code permit parametric design space exploration of candidate pump configurations and provide pump performance data for engine system evaluation. The PUMPA code has been integrated with the Numerical Propulsion System Simulation (NPSS) code and an expander rocket engine system has been simulated. The mean line pump flow code runs as an integral part of the NPSS rocket engine system simulation and provides key pump performance information directly to the system model at all operating conditions.

  13. Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

    NASA Astrophysics Data System (ADS)

    Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

    2016-09-01

    Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

  14. Mean Flow Augmented Acoustics in Rocket Systems

    NASA Technical Reports Server (NTRS)

    Fischbach, Sean R.

    2015-01-01

    Combustion instability in solid rocket motors and liquid engines is a complication that continues to plague designers and engineers. Many rocket systems experience violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process and gas dynamics. During sever cases of combustion instability fluctuation amplitudes can reach values equal to or greater than the average chamber pressure. Large amplitude oscillations lead to damaged injectors, loss of rocket performance, damaged payloads, and in some cases breach of case/loss of mission. Historic difficulties in modeling and predicting combustion instability has reduced most rocket systems experiencing instability into a costly fix through testing paradigm or to scrap the system entirely.

  15. AEROSOL NUCLEATION AND GROWTH DURING LAMINAR TUBE FLOW: MAXIMUM SATURATIONS AND NUCLEATION RATES. (R827354C008)

    EPA Science Inventory

    An approximate method of estimating the maximum saturation, the nucleation rate, and the total number nucleated per second during the laminar flow of a hot vapour–gas mixture along a tube with cold walls is described. The basis of the approach is that the temperature an...

  16. Electrochemical cell for rebalancing REDOX flow system

    NASA Technical Reports Server (NTRS)

    Thaller, L. H. (Inventor)

    1979-01-01

    An electrically rechargeable REDOX cell or battery system including one of more rebalancing cells is described. Each rebalancing cell is divided into two chambers by an ion permeable membrane. The first chamber is fed with gaseous hydrogen and a cathode fluid which is circulated through the cathode chamber of the REDOX cell is also passed through the second chamber of the rebalancing cell. Electrochemical reactions take place on the surface of insert electrodes in the first and second chambers to rebalance the electrochemical capacity of the anode and cathode fluids of the REDOX system.

  17. MAG-GATE System for Molten metal Flow Control

    SciTech Connect

    Richard D. Nathenson, P.E.

    2004-05-15

    The need for improved active flow control has been recognized as part of the Steel Industry Technology Roadmap. Under TRP 9808 for the American Iron and Steel Institute and the Department of Energy, Concept Engineering Group Inc. has developed MAG-GATE{trademark}, an electromagnetic system for active molten metal flow control. Two hot steel tests were successfully conducted in 2003 at the Whemco Foundry Division, Midland, PA. Approximately 110,000 pounds of 0.2% carbon steel were poured through the device subject to electromagnetic flow control. Excellent agreement between predicted and actual flow control was found. A survey of the molten metal flow control practices at 100 continuous casters in North America was also conducted in 2003. This report summarizes the results of the development program to date. Preliminary designs are described for the next step of a beta test at an operating billet/bloom or slab caster.

  18. Light-governed capillary flow in microfluidic systems.

    PubMed

    Jiang, Li; Erickson, David

    2013-01-14

    Light-based flow systems for point-of-care devices are of interest because, in principle, sunlight could be used to operate them, potentially allowing for high functionality with minimal device complexity and expense. A light-operated method to drive flow using poly(N-isopropylacrylamide), a 'smart' polymer that changes wettability as a function of temperature, is introduced. It is grafted onto a carbon black-polydimethylsiloxane surface, which converts light into a thermal pattern that valves flow at user-defined locations. Flow rates are demonstrated ranging from 4 μL min(-1) at 25 °C to 0.1 μL min(-1) at 40 °C. The valving dynamics are also characterised, and a response time of less than 4 s is shown. Light-operated flow could provide the simple architecture and advanced functionality needed in low-resource point-of-care devices. PMID:23015307

  19. Method, apparatus and system for controlling fluid flow

    DOEpatents

    McMurtrey, Ryan D.; Ginosar, Daniel M.; Burch, Joesph V.

    2007-10-30

    A system, apparatus and method of controlling the flow of a fluid are provided. In accordance with one embodiment of the present invention, a flow control device includes a valve having a flow path defined therethrough and a valve seat in communication with the flow path with a valve stem disposed in the valve seat. The valve stem and valve seat are cooperatively configured to cause mutual relative linear displacement thereof in response to rotation of the valve stem. A gear member is coupled with the rotary stem and a linear positioning member includes a portion which complementarily engages the gear member. Upon displacement of the linear positioning member along a first axis, the gear member and rotary valve stem are rotated about a second axis and the valve stem and valve seat are mutually linearly displaced to alter the flow of fluid through the valve.

  20. Thermally sensitive block copolymer particles prepared via aerosol flow reactor method: Morphological characterization and behavior in water.

    PubMed

    Nykänen, Antti; Rahikkala, Antti; Hirvonen, Sami-Pekka; Aseyev, Vladimir; Tenhu, Heikki; Mezzenga, Raffaele; Raula, Janne; Kauppinen, Esko; Ruokolainen, Janne

    2012-10-23

    This work describes properties of thermo-sensitive submicron sized particles having the same chemical composition but different morphologies. These particles have been prepared with an aerosol technique using dimethylformamide solutions of linear polystyrene-block-poly(N-isopropylacrylamide-block-polystyrene, PS-b-PNIPAM-b-PS. The particles were characterized by cryo-electron microscopy, microcalorimetry, and light scattering. Block-copolymers self-assembled within the particles forming onion-like, gyroid-like, and spherical morphologies having poly(N-isopropylacrylamide) matrix and physically cross-linking polystyrene domains. The particles were dispersed in aqueous media and their behavior in water was studied both below and above the lower critical solution temperature of poly(N-isopropylacrylamide). We found out that the particles with spherical and gyroid-like morphologies swell considerably in water at 20 °C, whereas at 40 °C the particles resemble more of those studied without water treatment. Light scattering experiments showed that the particles gradually aggregate and precipitate with time at 40 °C. Microcalorimetric studies revealed for all three studied morphologies that PNIPAM undergoes a two-step transition due to the different hydration levels of PNIPAM inside and outside the particles. Thicknesses of the PS and PNIPAM layers within the onion-like particles were analyzed using the TEM micrographs by fitting a model of electron density to the integrated electron intensity data. The surface layer of the particles was found out to be PNIPAM, which was supported by light scattering and microcalorimetry. It was also found out from the TEM micrograph analysis that the width of the outmost PS layer is considerably thinner than the one in the dry state prior to immersion in water, and a degradation scheme is proposed to explain these results. PMID:23150721

  1. Thermally sensitive block copolymer particles prepared via aerosol flow reactor method: Morphological characterization and behavior in water

    PubMed Central

    Nykänen, Antti; Rahikkala, Antti; Hirvonen, Sami-Pekka; Aseyev, Vladimir; Tenhu, Heikki; Mezzenga, Raffaele; Raula, Janne; Kauppinen, Esko; Ruokolainen, Janne

    2012-01-01

    This work describes properties of thermo-sensitive submicron sized particles having the same chemical composition but different morphologies. These particles have been prepared with an aerosol technique using dimethylformamide solutions of linear polystyrene-block-poly(N-isopropylacrylamide-block-polystyrene, PS-b-PNIPAM-b-PS. The particles were characterized by cryo-electron microscopy, microcalorimetry, and light scattering. Block-copolymers self-assembled within the particles forming onion-like, gyroid-like, and spherical morphologies having poly(N-isopropylacrylamide) matrix and physically cross-linking polystyrene domains. The particles were dispersed in aqueous media and their behavior in water was studied both below and above the lower critical solution temperature of poly(N-isopropylacrylamide). We found out that the particles with spherical and gyroid-like morphologies swell considerably in water at 20 °C, whereas at 40 °C the particles resemble more of those studied without water treatment. Light scattering experiments showed that the particles gradually aggregate and precipitate with time at 40 °C. Microcalorimetric studies revealed for all three studied morphologies that PNIPAM undergoes a two-step transition due to the different hydration levels of PNIPAM inside and outside the particles. Thicknesses of the PS and PNIPAM layers within the onion-like particles were analyzed using the TEM micrographs by fitting a model of electron density to the integrated electron intensity data. The surface layer of the particles was found out to be PNIPAM, which was supported by light scattering and microcalorimetry. It was also found out from the TEM micrograph analysis that the width of the outmost PS layer is considerably thinner than the one in the dry state prior to immersion in water, and a degradation scheme is proposed to explain these results. PMID:23150721

  2. Stochastic modeling of a lava-flow aquifer system

    USGS Publications Warehouse

    Cronkite-Ratcliff, Collin; Phelps, Geoffrey A.

    2014-01-01

    This report describes preliminary three-dimensional geostatistical modeling of a lava-flow aquifer system using a multiple-point geostatistical model. The purpose of this study is to provide a proof-of-concept for this modeling approach. An example of the method is demonstrated using a subset of borehole geologic data and aquifer test data from a portion of the Calico Hills Formation, a lava-flow aquifer system that partially underlies Pahute Mesa, Nevada. Groundwater movement in this aquifer system is assumed to be controlled by the spatial distribution of two geologic units—rhyolite lava flows and zeolitized tuffs. The configuration of subsurface lava flows and tuffs is largely unknown because of limited data. The spatial configuration of the lava flows and tuffs is modeled by using a multiple-point geostatistical simulation algorithm that generates a large number of alternative realizations, each honoring the available geologic data and drawn from a geologic conceptual model of the lava-flow aquifer system as represented by a training image. In order to demonstrate how results from the geostatistical model could be analyzed in terms of available hydrologic data, a numerical simulation of part of an aquifer test was applied to the realizations of the geostatistical model.

  3. Deposition of ultrafine aerosols in rat nasal molds

    SciTech Connect

    Cheng, Y.S.; Hansen, G.K.; Su, Y.F.; Yeh, H.C. ); Morgan, K.T. )

    1990-01-01

    To evaluate the health effect of air pollutants on the respiratory tract, it is critical to determine the regional deposition of inhaled aerosols. Information on deposition of larger particles in the nasal passages of laboratory animals is available; the deposition fraction increases with increasing particle size. However, little deposition information is available for ultrafine particles of less than 0.2 {mu}m. Three clear, plastic molds (models) of the nasal passages of F344/N rats, prepared from metal replica casts used in these studies. Total deposition of ultrafine aerosols in the casts was determined by using a unidirectional flow system. The pressure drops measured in the casts were a function of flow rate to the power of 1.4-1.6, indicating that flow through the nasal passages has nonlaminar components. Deposition data were obtained by using monodisperse sodium chloride aerosols with particle sizes ranging from 0.2 to 0.005 {mu}m, at inspiratory and expiratory flow rates of 200 to 600 ml/min. Similar deposition data were obtained for two of the casts studied. Deposition efficiency was greatest for the smallest particles, and decreased with increasing particle size and flow rate. At an inspiratory flow rate of 400 ml/min, which is comparable to the mean respiratory flow of an adult male F344 rat with a respiratory minute volume of 200 ml, deposition efficiencies reached 40 and 70% for 0.01- and 0.005-{mu}m particles, respectively.

  4. Flow Analysis on a Limited Volume Chilled Water System

    SciTech Connect

    Zheng, Lin

    2012-07-31

    LANL Currently has a limited volume chilled water system for use in a glove box, but the system needs to be updated. Before we start building our new system, a flow analysis is needed to ensure that there are no high flow rates, extreme pressures, or any other hazards involved in the system. In this project the piping system is extremely important to us because it directly affects the overall design of the entire system. The primary components necessary for the chilled water piping system are shown in the design. They include the pipes themselves (perhaps of more than one diameter), the various fitting used to connect the individual pipes to form the desired system, the flow rate control devices (valves), and the pumps that add energy to the fluid. Even the most simple pipe systems are actually quite complex when they are viewed in terms of rigorous analytical considerations. I used an 'exact' analysis and dimensional analysis considerations combined with experimental results for this project. When 'real-world' effects are important (such as viscous effects in pipe flows), it is often difficult or impossible to use only theoretical methods to obtain the desired results. A judicious combination of experimental data with theoretical considerations and dimensional analysis are needed in order to reduce risks to an acceptable level.

  5. ATI TDA 5A aerosol generator evaluation

    SciTech Connect

    Gilles, D.A.

    1998-07-27

    Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.

  6. TRAJECTORY OF AEROSOL DROPLETS FROM A SPRAYED BACTERIAL SUSPENSION

    EPA Science Inventory

    Simulated droplet trajectories of a polydispersed microbial aerosol in a laminar air flow regimen were compared with observed ispersal patterns of aerosolized Bacillus subtilis subsp. niger spores in quasilaminar airflow. imulated dispersal patterns could be explained in terms of...

  7. Theoretical and global scale model studies of the atmospheric sulfur/aerosol system

    NASA Technical Reports Server (NTRS)

    Kasibhatla, Prasad

    1996-01-01

    The primary focus during the third-phase of our on-going multi-year research effort has been on 3 activities. These are: (1) a global-scale model study of the anthropogenic component of the tropospheric sulfur cycle; (2) process-scale model studies of the factors influencing the distribution of aerosols in the remote marine atmosphere; and (3) an investigation of the mechanism of the OH-initiated oxidation of DMS in the remote marine boundary layer. In this paper, we describe in more detail our research activities in each of these areas. A major portion of our activities during the fourth and final phase of this project will involve the preparation and submission of manuscripts describing the results from our model studies of marine boundary-layer aerosols and DMS-oxidation mechanisms.

  8. Advancing Model Systems for Fundamental Laboratory Studies of Sea Spray Aerosol Using the Microbial Loop.

    PubMed

    Lee, Christopher; Sultana, Camille M; Collins, Douglas B; Santander, Mitchell V; Axson, Jessica L; Malfatti, Francesca; Cornwell, Gavin C; Grandquist, Joshua R; Deane, Grant B; Stokes, M Dale; Azam, Farooq; Grassian, Vicki H; Prather, Kimberly A

    2015-08-20

    Sea spray aerosol (SSA) particles represent one of the most abundant surfaces available for heterogeneous reactions to occur upon and thus profoundly alter the composition of the troposphere. In an effort to better understand tropospheric heterogeneous reaction processes, fundamental laboratory studies must be able to accurately reproduce the chemical complexity of SSA. Here we describe a new approach that uses microbial processes to control the composition of seawater and SSA particle composition. By inducing a phytoplankton bloom, we are able to create dynamic ecosystem interactions between marine microorganisms, which serve to alter the organic mixtures present in seawater. Using this controlled approach, changes in seawater composition become reflected in the chemical composition of SSA particles 4 to 10 d after the peak in chlorophyll-a. This approach for producing and varying the chemical complexity of a dominant tropospheric aerosol provides the foundation for further investigations of the physical and chemical properties of realistic SSA particles under controlled conditions. PMID:26196268

  9. Role of anthropogenic aerosols in the20th century surface solar radiation, temperature, and meridional heat transport in the Max Planck Earth System Model

    NASA Astrophysics Data System (ADS)

    Dallafior, Tanja; Folini, Doris; Knutti, Reto; Wild, Martin

    2016-04-01

    It is still debated, to what degree anthropogenic aerosols were affected surface temperatures - especially over sea surfaces - through alteration of surface solar radiation (SSR). Previous work using mixed-layer ocean equilibria corroborated the relevance of anthropogenic aerosols for surface temperature response patterns obtained. Here we complement these studies by fully coupled simulations with the Max Planck Earth System Model (MPI-ESM) in its CMIP5 version. Experiments comprise preindustrial control and historical as in CMIP5, as well as transient experiments 1850 - 2000 with either anthropogenic aerosols or well-mixed greenhouse gases (WMGHG) kept at 1850 levels. With this suite of experiments, we analyse the impact of anthropogenic aerosols and WMGHG on the global energy balance and provide estimates of atmospheric and oceanic meridional heat transport changes in our modeling setup. We find that Global mean surface temperature responses to single forcings are additive. Furthermore, spatial surface temperature response patterns in the WMGHG only experiment are more strongly correlated with the historical experiment than the aerosol only case. We compare transient and equilibrium responses and discuss potential implications of not allowing for cloud-aerosol interactions in the transient modeling set-up.

  10. System and method for bidirectional flow and controlling fluid flow in a conduit

    DOEpatents

    Ortiz, Marcos German

    1999-01-01

    A system for measuring bidirectional flow, including backflow, of fluid in a conduit. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit.

  11. System and method for bidirectional flow and controlling fluid flow in a conduit

    DOEpatents

    Ortiz, M.G.

    1999-03-23

    A system for measuring bidirectional flow, including backflow, of fluid in a conduit is disclosed. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit. 3 figs.

  12. The lofting of Western Pacific regional aerosol by island thermodynamics as observed around Borneo

    NASA Astrophysics Data System (ADS)

    Robinson, N. H.; Allan, J. D.; Trembath, J. A.; Rosenberg, P. D.; Allen, G.; Coe, H.

    2012-07-01

    Vertical profiles of aerosol chemical composition, number concentration and size were measured throughout the lower troposphere of Borneo, a large tropical island in the western Pacific Ocean. Aerosol composition, size and number concentration measurements (using an Aerodyne Aerosol Mass Spectrometer, Passive Cavity Aerosol Spectrometer Probe and Condensation Particle Counter, respectively) were made both upwind and downwind of Borneo, as well as over the island itself, on board the UK BAe-146 research aircraft as part of the OP3 project. Two meteorological regimes were identified - one dominated by isolated terrestrial convection (ITC) which peaked in the afternoon, and the other characterised by more regionally active mesoscale convective systems (MCS). Upwind profiles show aerosol to be confined to a shallow marine boundary layer below 930 ± 10 hPa (~760 m above sea level, a.s.l.). As this air mass advects over the island with the mean free troposphere synoptic flow during the ITC-dominated regime, it is convectively lofted above the terrestrial surface mixed layer to heights of between 945 ± 22 (~630 m a.s.l.) and 740 ± 44 hPa (~2740 m a.s.l.), consistent with a coupling between the synoptic steering level flow and island sea breeze circulations. Terrestrial aerosol was observed to be lofted into this higher layer through both moist convective uplift and transport through turbulent diurnal sea-breeze cells. At the peak of convective activity in the mid-afternoons, organic aerosol loadings in the lofted layer were observed to be substantially higher than in the morning (by a mean factor of three). This organic matter is dominated by secondary aerosol from processing of biogenic gas phase precursors. Aerosol number concentration profiles suggest formation of new particles aloft in the atmosphere. By the time the air mass reaches the west coast of the island, terrestrial aerosol is enhanced in the lofted layer. Such uplift of aerosol in Borneo is expected to

  13. A multi-agent system for monitoring patient flow.

    PubMed

    Rosati, Samanta; Tralli, Augusta; Balestra, Gabriella

    2013-01-01

    Patient flow within a healthcare facility may follow different and, sometimes, complicated paths. Each path phase is associated with the documentation of the activities carried out during it and may require the consultation of clinical guidelines, medical literature and the use of specific software and decision aid systems. In this study we present the design of a Patient Flow Management System (PFMS) based on Multi Agent Systems (MAS) methodology. System requirements were identified by means of process modeling tools and a MAS consisting of six agents was designed and is under construction. Its main goal is to support both the medical staff during the health care process and the hospital managers in assuring that all the required documentation is completed and available. Moreover, such a tool can be used for the assessment and comparison of different clinical pathways, in order to identify possible improvementsand the optimum patient flow. PMID:23920718

  14. Two-phase flows within systems with ambient pressure

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Braun, M. J.; Wheeler, R. L., III; Mullen, R. L.

    1985-01-01

    In systems where the design inlet and outlet pressures are maintained above the thermodynamic critical pressure, it is often assumed that two phase flows within the system cannot occur. Designers rely on this simple rule of thumb to circumvent problems associated with a highly compressible two phase flow occurring within the supercritical pressure system along with the uncertainties in rotordynamics, load capacity, heat transfer, fluid mechanics, and thermophysical property variations. The simple rule of thumb is adequate in many low power designs but is inadequate for high performance turbomachines and linear systems, where two phase regions can exist even though outlet pressure is greater than critical pressure. Rotordynamic-fluid-mechanic restoring forces depend on momentum differences, and those for a two phase zone can differ significantly from those for a single-phase zone. Using the Reynolds equation the angular velocity, eccentricity, geometry, and ambient conditions are varied to determine the point of two phase flow incipience.

  15. Portable Fluorescence Imaging System for Hypersonic Flow Facilities

    NASA Technical Reports Server (NTRS)

    Wilkes, J. A.; Alderfer, D. W.; Jones, S. B.; Danehy, P. M.

    2003-01-01

    A portable fluorescence imaging system has been developed for use in NASA Langley s hypersonic wind tunnels. The system has been applied to a small-scale free jet flow. Two-dimensional images were taken of the flow out of a nozzle into a low-pressure test section using the portable planar laser-induced fluorescence system. Images were taken from the center of the jet at various test section pressures, showing the formation of a barrel shock at low pressures, transitioning to a turbulent jet at high pressures. A spanwise scan through the jet at constant pressure reveals the three-dimensional structure of the flow. Future capabilities of the system for making measurements in large-scale hypersonic wind tunnel facilities are discussed.

  16. Systems and methods for rebalancing redox flow battery electrolytes

    DOEpatents

    Pham, Ai Quoc; Chang, On Kok

    2015-03-17

    Various methods of rebalancing electrolytes in a redox flow battery system include various systems using a catalyzed hydrogen rebalance cell configured to minimize the risk of dissolved catalyst negatively affecting flow battery performance. Some systems described herein reduce the chance of catalyst contamination of RFB electrolytes by employing a mediator solution to eliminate direct contact between the catalyzed membrane and the RFB electrolyte. Other methods use a rebalance cell chemistry that maintains the catalyzed electrode at a potential low enough to prevent the catalyst from dissolving.

  17. A contribution about ferrofluid based flow manipulation and locomotion systems

    NASA Astrophysics Data System (ADS)

    Zimmermann, K.; Zeidis, I.; Bohm, V.; Popp, J.

    2009-02-01

    With the background of developing apedal bionic inspired locomotion systems for future application fields like autonomous (swarm) robots, medical engineering and inspection systems, this article presents a selection of locomotion systems with bifluidic flow control using ferrofluid. By controlling the change of shape, position and pressure of the ferrofluid in a secondary low viscous fluid by magnetic fields locomotion of objects or the ferrofluid itself can be realised. The locomotion of an object is caused in the first example by a ferrofluid generated flow of the secondary fluid and in the second and third case by the direct alteration of the ferrofluid position.

  18. Liquid-crystalline and microemulsion phase behavior in alcohol-free aerosol-OT/oil/brine systems

    SciTech Connect

    Ghosh, O.; Miller, C.A.

    1987-08-13

    The phase behavior of systems containing the pure anionic surfactant Aerosol OT or sodium bis(2-ethylhexyl) sulfosuccinate was studied as a function of salt concentration, surfactant concentration, alkane carbon number, and water-to-oil ratio. Since the hydrophilic and lipophilic properties of Aerosol OT are nearly balanced, the surfactant forms microemulsions with water and oil in the absence of cosurfactant, allowing for simplified representation of phase behavior. In particular, this property aided in the understanding of transitions between the aqueous surfactant phase behavior and the well-studied oil-rich microemulsion regime. With the addition of salt to dilute alcohol-free surfactant-water mixtures, transitions in the liquid-crystalline phases similar to those seen previously for systems containing petroleum sulfonates and other anionic surfactants with alcohol cosurfactants were found. When hydrocarbons of various chain lengths were equilibrated with the aqueous surfactant solutions, again behavior similar to that of anionic surfactants with alcohol cosurfactants was observed. Pseudoternary diagrams of surfactant-brine-oil were constructed at various brine salinities with n-dodecane as the oil. The assumption that brine acts as a pseudocomponent was found to work best at salinities well below and well above the optimum and at low surfactant concentrations. In any case, the results provide extensive information on phase behavior of a four-component system containing a pure anionic surfactant, a pure hydrocarbon, and sodium chloride brine over a region of considerable interest for enhanced oil recovery and other applications.

  19. Aerosol - cloud - water vapor relations for cloud systems of different heights

    NASA Astrophysics Data System (ADS)

    Stathopoulos, Stavros; Kourtidis, Konstantinos; Georgoulias, Aristeidis

    2016-04-01

    Here we examine the annual and seasonal aerosol - cloud relations over three major urban clusters of China, for different cloud heights and atmospheric water vapor amounts, using a decade of Aerosol Optical Depth at 550nm (AOD), Cloud Cover (CC), Cloud Optical Depth (COD), Water Vapor (WV) and Cloud Top Pressure (CTP) data from the MODIS instrument. Over all regions (spanning from temperate to tropical monsoon climates) and for all seasons, CC is found to increase with AOD, WV and cloud height. Aerosols, at low WV environments and under constant cloud height, have less impact on CC than at high WV environments. In addition, AOD has a varying influence on COD depending on CTP. Finally, COD is found to increase with height for low and middle height clouds, and with increasing AOD, especially at low AOD, the latter being in line with the expected first indirect effect. This research has been financed under the FP7 Programme MarcoPolo (Grand Number 606953, Theme SPA.2013.3.2-01).

  20. Why Is Improvement of Earth System Models So Elusive? Challenges and Strategies From Dust Aerosol Modeling

    NASA Astrophysics Data System (ADS)

    Miller, R. L.; Pérez García-Pando, C.; Perlwitz, J. P.; Ginoux, P. A.

    2015-12-01

    Past decades have seen an accelerating increase in computing efficiency,while climate models are representing a rapidly widening set ofphysical processes. Yet simulations of some fundamental aspects ofclimate like precipitation or aerosol forcing remain highly uncertainand resistent to progress. Dust aerosol modeling of soil particleslofted by wind erosion has seen a similar conflict between increasingmodel sophistication and remaining uncertainty. Dust aerosols perturbthe energy and water cycles by scattering radiation and acting as icenuclei, while mediating atmospheric chemistry and marinephotosynthesis (and thus the carbon cycle). These effects take placeacross scales from the dimensions of an ice crystal to theplanetary-scale circulation that disperses dust far downwind of itsparent soil. Representing this range leads to several modelingchallenges. Should we limit complexity in our model, which consumescomputer resources and inhibits interpretation? How do we decide if aprocess involving dust is worthy of inclusion within our model? Canwe identify a minimal representation of a complex process that isefficient yet retains the physics relevant to climate? Answeringthese questions about the appropriate degree of representation isguided by model evaluation, which presents several more challenges.How do we proceed if the available observations do not directlyconstrain our process of interest? (This could result from competingprocesses that influence the observed variable and obscure thesignature of our process of interest.) Examples will be presentedfrom dust modeling, with lessons that might be more broadlyapplicable. The end result will either be clinical depression or thereassuring promise of continued gainful employment as the communityconfronts these challenges.

  1. Information systems for material flow management in construction processes

    NASA Astrophysics Data System (ADS)

    Mesároš, P.; Mandičák, T.

    2015-01-01

    The article describes the options for the management of material flows in the construction process. Management and resource planning is one of the key factors influencing the effectiveness of construction project. It is very difficult to set these flows correctly. The current period offers several options and tools to do this. Information systems and their modules can be used just for the management of materials in the construction process.

  2. Whole-body nanoparticle aerosol inhalation exposures.

    PubMed

    Yi, Jinghai; Chen, Bean T; Schwegler-Berry, Diane; Frazer, Dave; Castranova, Vince; McBride, Carroll; Knuckles, Travis L; Stapleton, Phoebe A; Minarchick, Valerie C; Nurkiewicz, Timothy R

    2013-01-01

    Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter < 200 nm and a geometric standard deviation σg < 2.5 (5). The generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size (6), which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria (5). A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m(3) whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm(3)) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m(3)). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpre and Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M

  3. Whole-Body Nanoparticle Aerosol Inhalation Exposures

    PubMed Central

    Yi, Jinghai; Chen, Bean T.; Schwegler-Berry, Diane; Frazer, Dave; Castranova, Vince; McBride, Carroll; Knuckles, Travis L.; Stapleton, Phoebe A.; Minarchick, Valerie C.; Nurkiewicz, Timothy R.

    2013-01-01

    Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter < 200 nm and a geometric standard deviation σg < 2.5 5. The generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size 6, which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria 5. A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m3 whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm3) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m3). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpreand Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M/(Q*t), where Q is

  4. 93. TEMPERATURE AND FLOW RATE CONTROLS FOR SYSTEM 1 AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    93. TEMPERATURE AND FLOW RATE CONTROLS FOR SYSTEM 1 AND SYSTEM 2, FACING WEST IN MECHANICAL EQUIPMENT ROOM (101), LSB (BLDG. 770) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  5. Aerosol Optical Depth over Europe: Evaluation of the CALIOPE air quality modelling system with direct-sun AERONET observations

    NASA Astrophysics Data System (ADS)

    Basart, Sara; Pay, María. Teresa; Pérez, Carlos; Cuevas, Emilio; Jorba, Oriol; Piot, Matthias; María Baldasano, Jose

    2010-05-01

    In the frame of the CALIOPE project (Baldasano et al., 2008), the Barcelona Supercomputing Center (BSC-CNS) currently operates a high-resolution air quality forecasting system based on daily photochemical forecasts in Europe (12km x 12km resolution) with the WRF-ARW/HERMES/CMAQ modelling system (http://www.bsc.es/caliope) and desert dust forecasts over Southern Europe with BSC-DREAM8b (Pérez et al., 2006; http://www.bsc.es/projects/earthscience/DREAM). High resolution simulations and forecasts are possible through their implementation on MareNostrum supercomputer at BSC-CNS. As shown in previous air quality studies (e.g. Rodríguez et al., 2001; Jiménez-Guerrero et al., 2008), the contribution of desert dust on particulate matter levels in Southern Europe is remarkable due to its proximity to African desert dust sources. When considering only anthropogenic emissions (Baldasano et al., 2008) and the current knowledge about aerosol physics and chemistry, chemistry-transport model simulations underestimate the PM10 concentrations by 30-50%. As a first approach, the natural dust contribution from BSC-DREAM8b is on-line added to the anthropogenic aerosol output of CMAQ. The aim of the present work is the quantitative evaluation of the WRF-ARW/HERMES/ CMAQ/BSC-DREAM8b forecast system to simulate the Aerosol Optical Depth (AOD) over Europe. The performance of the modelled AOD has been quantitatively evaluated with discrete and categorical (skill scores) statistics by a comparison to direct-sun AERONET observations for 2004. The contribution of different types of aerosols will be analyzed by means of the O'Neill fine mode AOD products (O'Neill et al., 2001). A previous aerosol characterization of AERONET data was performed (Basart et al., 2009) in order to discriminate the different aerosol source contributions within the study region. The results indicate a remarkable improvement in the discrete and skill-scores evaluation (accuracy, critical success index and

  6. A Ground-Based 2-Micron DIAL System to Profile Tropospheric CO2 and Aerosol Distributions for Atmospheric Studies

    NASA Technical Reports Server (NTRS)

    Ismail, Syed; Koch, Grady; Abedin, Nurul; Refaat, Tamer; Rubio, Manuel; Davis, Kenneth; Miller, Charles; Singh, Upendra

    2006-01-01

    System will operate at a temperature insensitive CO2 line (2050.967 nm) with side-line tuning and off-set locking. Demonstrated an order of magnitude improvement in laser line locking needed for high precision measurements, side-line operation, and simultaneously double pulsing and line locking. Detector testing of phototransistor has demonstrated sensitivity to aerosol features over long distances in the atmosphere and resolve features approx. 100m. Optical systems that collect light onto small area detectors work well. Receiver optical designs are being optimized and data acquisition systems developed. CO2 line parameter characterization in progress In situ sensor calibration in progress for validation of DIAL CO2 system.

  7. Regularized image system for Stokes flow outside a solid sphere

    NASA Astrophysics Data System (ADS)

    Wróbel, Jacek K.; Cortez, Ricardo; Varela, Douglas; Fauci, Lisa

    2016-07-01

    The image system for a three-dimensional flow generated by regularized forces outside a solid sphere is formulated and implemented as an extension of the method of regularized Stokeslets. The method is based on replacing a point force given by a delta distribution with a smooth localized function and deriving the exact velocity field produced by the forcing. In order to satisfy zero-flow boundary conditions at a solid sphere, the image system for singular Stokeslets is generalized to give exact cancellation of the regularized flow at the surface of the sphere. The regularized image system contains the same elements as the singular counterpart but with coefficients that depend on a regularization parameter. As this parameter vanishes, the expressions reduce to the image system of the singular Stokeslet. The expression relating force and velocity can be inverted to compute the forces that generate a given velocity boundary condition elsewhere in the flow. We present several examples within the context of biological flows at the microscale in order to validate and highlight the usefulness of the image system in computations.

  8. Research on MEMS sensor in hydraulic system flow detection

    NASA Astrophysics Data System (ADS)

    Zhang, Hongpeng; Zhang, Yindong; Liu, Dong; Ji, Yulong; Jiang, Jihai; Sun, Yuqing

    2011-05-01

    With the development of mechatronics technology and fault diagnosis theory, people regard flow information much more than before. Cheap, fast and accurate flow sensors are urgently needed by hydraulic industry. So MEMS sensor, which is small, low cost, well performed and easy to integrate, will surely play an important role in this field. Based on the new method of flow measurement which was put forward by our research group, this paper completed the measurement of flow rate in hydraulic system by setting up the mathematical model, using numerical simulation method and doing physical experiment. Based on viscous fluid flow equations we deduced differential pressure-velocity model of this new sensor and did optimization on parameters. Then, we designed and manufactured the throttle and studied the velocity and pressure field inside the sensor by FLUENT. Also in simulation we get the differential pressure-velocity curve .The model machine was simulated too to direct experiment. In the static experiments we calibrated the MEMS sensing element and built some sample sensors. Then in a hydraulic testing system we compared the sensor signal with a turbine meter. It presented good linearity and could meet general hydraulic system use. Based on the CFD curves, we analyzed the error reasons and made some suggestion to improve. In the dynamic test, we confirmed this sensor can realize high frequency flow detection by a 7 piston-pump.

  9. Research on MEMS sensor in hydraulic system flow detection

    NASA Astrophysics Data System (ADS)

    Zhang, Hongpeng; Zhang, Yindong; Liu, Dong; Ji, Yulong; Jiang, Jihai; Sun, Yuqing

    2010-12-01

    With the development of mechatronics technology and fault diagnosis theory, people regard flow information much more than before. Cheap, fast and accurate flow sensors are urgently needed by hydraulic industry. So MEMS sensor, which is small, low cost, well performed and easy to integrate, will surely play an important role in this field. Based on the new method of flow measurement which was put forward by our research group, this paper completed the measurement of flow rate in hydraulic system by setting up the mathematical model, using numerical simulation method and doing physical experiment. Based on viscous fluid flow equations we deduced differential pressure-velocity model of this new sensor and did optimization on parameters. Then, we designed and manufactured the throttle and studied the velocity and pressure field inside the sensor by FLUENT. Also in simulation we get the differential pressure-velocity curve .The model machine was simulated too to direct experiment. In the static experiments we calibrated the MEMS sensing element and built some sample sensors. Then in a hydraulic testing system we compared the sensor signal with a turbine meter. It presented good linearity and could meet general hydraulic system use. Based on the CFD curves, we analyzed the error reasons and made some suggestion to improve. In the dynamic test, we confirmed this sensor can realize high frequency flow detection by a 7 piston-pump.

  10. Preliminary design of an intermittent smoke flow visualization system

    NASA Technical Reports Server (NTRS)

    Ward, Donald T.; Myatt, James H.

    1993-01-01

    A prototype intermittent flow visualization system that was designed to study vortex flow field dynamics has been constructed and tested through its ground test phase. It produces discrete pulses of dense white smoke consisting of particles of terephthalic acid by the pulsing action of a fast-acting three-way valve. The trajectories of the smoke pulses can be tracked by a video imaging system without intruding in the flow around in flight. Two methods of pulsing the smoke were examined. The simplest and safest approach is to simply divert the smoke between the two outlet ports on the valve; this approach should be particularly effective if it were desired to inject smoke at two locations during the same test event. The second approach involves closing off one of the outlet ports to momentarily block the flow. The second approach requires careful control of valve dwell times to avoid excessive pressure buildup within the cartridge container. This method also increases the velocity of the smoke injected into the flow. The flow of the smoke has been blocked for periods ranging from 30 to 80 milliseconds, depending on the system volume and the length of time the valve is allowed to remain open between valve closings.

  11. Migration Systems in Europe: Evidence From Harmonized Flow Data

    PubMed Central

    Kim, Keuntae; Raymer, James

    2014-01-01

    Empirical tests of migration systems theory require consistent and complete data on international migration flows. Publicly available data, however, represent an inconsistent and incomplete set of measurements obtained from a variety of national data collection systems. We overcome these obstacles by standardizing the available migration reports of sending and receiving countries in the European Union and Norway each year from 2003–2007 and by estimating the remaining missing flows. The resulting harmonized estimates are then used to test migration systems theory. First, locating thresholds in the size of flows over time, we identify three migration systems within the European Union and Norway. Second, examining the key determinants of flows with respect to the predictions of migration systems theory, our results highlight the importance of shared experiences of nation-state formation, geography, and accession status in the European Union. Our findings lend support to migration systems theory and demonstrate that knowledge of migration systems may improve the accuracy of migration forecasts toward managing the impacts of migration as a source of social change in Europe. PMID:22791267

  12. Aerosols-cloud-climate -interactions in the Norwegian Earth System Model (NorESM). Importance of biogenic particles for cloud properties and anthropogenic indirect effect.

    NASA Astrophysics Data System (ADS)

    Seland, Ø.; Iversen, T.; Kirkevâg, A.

    2012-04-01

    According to the 4th assessment report of IPCC, major sources of uncertainty in anthropogenic climate change projections are inaccurate model description and weak knowledge of aerosols and their interactions with radiation and clouds, as well as the cloud feedback to radiative forcing. One important aspect of the associated uncertainty is the natural atmosphere. Anthropogenic climate change is an increment caused by anthropogenic emissions relative to the properties of the climate system untouched by man. This is crucial for the direct and indirect effects of aerosols, since the amount, size and physical properties of natural background particles strongly influence the same properties of the anthropogenic aerosol components. In many climate models where CDNC is calculated explicitly, CDNC is constrained by prescribing a lower bound below which calculated values are not allowed. This is done in order to keep the aerosol in-direct effect within estimated values. The rationale for using such a lower bound is to keep the aerosol radiative forcing constrained by the forcing of green-house gases and 20th century climate.We hypothesize this lower bound can be removed or made less strict by including aerosols of biogenic origin. We will present results and sensitivity studies from simulations with the NorESM where we have added contributions from organic carbon of natural origin both from vegetation and oceanic sources. By including aerosols of biogenic origin we obtain close to the median indirect radiative forcing reported by IPCC AR4, as well as reproducing the temperature increase in the 20th century. NorESM is based on the Earth system model CCSM4.0 from NCAR, but is using CAM4-Oslo instead of CAM4 as atmosphere model and an updated version of MICOM from the Bergen Climate Model (BCM) instead of the ocean model POP2. The aerosol module includes sea-salt, dust, sulphate, black carbon (BC) and particulate organic matter (OM). Primary aerosol size-distributions are

  13. System Size, Energy, Pseudorapidity, and Centrality Dependence of Elliptic Flow

    NASA Astrophysics Data System (ADS)

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Chetluru, V.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Harnarine, I.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Richardson, E.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Szostak, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Willhelm, D.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wyngaardt, S.; Wysłouch, B.

    2007-06-01

    This Letter presents measurements of the elliptic flow of charged particles as a function of pseudorapidity and centrality from Cu-Cu collisions at 62.4 and 200 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider. The elliptic flow in Cu-Cu collisions is found to be significant even for the most central events. For comparison with the Au-Au results, it is found that the detailed way in which the collision geometry (eccentricity) is estimated is of critical importance when scaling out system-size effects. A new form of eccentricity, called the participant eccentricity, is introduced which yields a scaled elliptic flow in the Cu-Cu system that has the same relative magnitude and qualitative features as that in the Au-Au system.

  14. A flow injection flow cytometry system for on-line monitoring of bioreactors.

    PubMed

    Zhao, R; Natarajan, A; Srienc, F

    1999-03-01

    For direct and on-line study of the physiological states of cell cultures, a robust flow injection system has been designed and interfaced with flow cytometry (FI-FCM). The core of the flow injection system includes a microchamber designed for sample processing. The design of this microchamber allows not only an accurate on-line dilution but also on-line cell fixation, staining, and washing. The flow injection part of the system was tested by monitoring the optical density of a growing E.coli culture on-line using a spectrophotometer. The entire growth curve, from lag phase to stationary phase, was obtained with frequent sampling. The performance of the entire FI-FCM system is demonstrated in three applications. The first is the monitoring of green fluorescent protein fluorophore formation kinetics in E.coli by visualizing the fluorescence evolution after protein synthesis is inhibited. The data revealed a subpopulation of cells that do not become fluorescent. In addition, the data show that single-cell fluorescence is distributed over a wide range and that the fluorescent population contains cells that are capable of reaching significantly higher expression levels than that indicated by the population average. The second application is the detailed flow cytometric evaluation of the batch growth dynamics of E.coli expressing Gfp. The collected single-cell data visualize the batch growth phases and it is shown that a state of balanced growth is never reached by the culture. The third application is the determination of distribution of DNA content of a S. cerevisiae population by automatically staining cells using a DNA-specific stain. Reproducibility of the on-line staining reaction shows that the system is not restricted to measuring the native properties of cells; rather, a wider range of cellular components could be monitored after appropriate sample processing. The system is thus particularly useful because it operates automatically without direct operator

  15. Code System to Calculate Tornado-Induced Flow Material Transport.

    SciTech Connect

    ANDRAE, R. W.

    1999-11-18

    Version: 00 TORAC models tornado-induced flows, pressures, and material transport within structures. Its use is directed toward nuclear fuel cycle facilities and their primary release pathway, the ventilation system. However, it is applicable to other structures and can model other airflow pathways within a facility. In a nuclear facility, this network system could include process cells, canyons, laboratory offices, corridors, and offgas systems. TORAC predicts flow through a network system that also includes ventilation system components such as filters, dampers, ducts, and blowers. These ventilation system components are connected to the rooms and corridors of the facility to form a complete network for moving air through the structure and, perhaps, maintaining pressure levels in certain areas. The material transport capability in TORAC is very basic and includes convection, depletion, entrainment, and filtration of material.

  16. Air-flow regulation system for a coal gasifier

    DOEpatents

    Fasching, George E.

    1984-01-01

    An improved air-flow regulator for a fixed-bed coal gasifier is provided which allows close air-flow regulation from a compressor source even though the pressure variations are too rapid for a single primary control loop to respond. The improved system includes a primary controller to control a valve in the main (large) air supply line to regulate large slow changes in flow. A secondary controller is used to control a smaller, faster acting valve in a secondary (small) air supply line parallel to the main line valve to regulate rapid cyclic deviations in air flow. A low-pass filter with a time constant of from 20 to 50 seconds couples the output of the secondary controller to the input of the primary controller so that the primary controller only responds to slow changes in the air-flow rate, the faster, cyclic deviations in flow rate sensed and corrected by the secondary controller loop do not reach the primary controller due to the high frequency rejection provided by the filter. This control arrangement provides at least a factor of 5 improvement in air-flow regulation for a coal gasifier in which air is supplied by a reciprocating compressor through a surge tank.

  17. OVERSMART Reporting Tool for Flow Computations Over Large Grid Systems

    NASA Technical Reports Server (NTRS)

    Kao, David L.; Chan, William M.

    2012-01-01

    Structured grid solvers such as NASA's OVERFLOW compressible Navier-Stokes flow solver can generate large data files that contain convergence histories for flow equation residuals, turbulence model equation residuals, component forces and moments, and component relative motion dynamics variables. Most of today's large-scale problems can extend to hundreds of grids, and over 100 million grid points. However, due to the lack of efficient tools, only a small fraction of information contained in these files is analyzed. OVERSMART (OVERFLOW Solution Monitoring And Reporting Tool) provides a comprehensive report of solution convergence of flow computations over large, complex grid systems. It produces a one-page executive summary of the behavior of flow equation residuals, turbulence model equation residuals, and component forces and moments. Under the automatic option, a matrix of commonly viewed plots such as residual histograms, composite residuals, sub-iteration bar graphs, and component forces and moments is automatically generated. Specific plots required by the user can also be prescribed via a command file or a graphical user interface. Output is directed to the user s computer screen and/or to an html file for archival purposes. The current implementation has been targeted for the OVERFLOW flow solver, which is used to obtain a flow solution on structured overset grids. The OVERSMART framework allows easy extension to other flow solvers.

  18. Impacts of increasing the aerosol complexity in the Met Office global NWP model

    NASA Astrophysics Data System (ADS)

    Mulcahy, Jane; Walters, David; Bellouin, Nicolas; Milton, Sean

    2014-05-01

    Inclusion of the direct and indirect radiative effects of aerosols in high resolution global numerical weather prediction (NWP) models is being increasingly recognised as important for the improved accuracy of short-range weather forecasts. In this study the impacts of increasing the aerosol complexity in the global NWP configuration of the Met Office Unified Model (MetUM) are investigated. A hierarchy of aerosol representations are evaluated including three dimensional monthly mean speciated aerosol climatologies, fully prognostic aerosols modelled using the CLASSIC aerosol scheme and finally, initialised aerosols using assimilated aerosol fields from the GEMS project. The prognostic aerosol schemes are better able to predict the temporal and spatial variation of atmospheric aerosol optical depth, which is particularly important in cases of large sporadic aerosol events such as large dust storms or forest fires. Including the direct effect of aerosols improves model biases in outgoing longwave radiation over West Africa due to a better representation of dust. Inclusion of the indirect aerosol effects has significant impacts on the SW radiation particularly at high latitudes due to lower cloud amounts in high latitude clean air regions. This leads to improved surface radiation biases at the North Slope of Alaska ARM site. Verification of temperature and height forecasts is also improved in this region. Impacts on the global mean model precipitation and large-scale circulation fields were found to be generally small in the short range forecasts. However, the indirect aerosol effect leads to a strengthening of the low level monsoon flow over the Arabian Sea and Bay of Bengal and an increase in precipitation over Southeast Asia. This study highlights the importance of including a more realistic treatment of aerosol-cloud interactions in global NWP models and the potential for improved global environmental prediction systems through the incorporation of more complex

  19. Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

    NASA Astrophysics Data System (ADS)

    Ortega, A. M.; Hayes, P. L.; Peng, Z.; Palm, B. B.; Hu, W.; Day, D. A.; Li, R.; Cubison, M. J.; Brune, W. H.; Graus, M.; Warneke, C.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.; Jimenez, J. L.

    2015-08-01

    Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA) that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An Oxidation Flow Reactor (OFR) was deployed to study SOA formation in real-time during the CalNex campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS) alternated sampling ambient and reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air, achieving equivalent atmospheric aging from hours up to several weeks in 3 min of processing. OH radical concentration was continuously stepped, obtaining measurements of real-time SOA formation and oxidation at multiple equivalent ages from 0.8 days-6.4 weeks. Enhancement of OA from aging showed a maximum net SOA production between 0.8-6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry, and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived VOC correlation, indicates the importance of relatively reactive (τOH ∼ 0.3 day) SOA precursors in the LA-Basin. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope ∼ -0.65). Oxidation state of carbon (OSC) in reactor SOA increased steeply with age and remained elevated (OSC ∼ 2) at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background) vs. photochemical age is similar to previous studies at low to moderate ages and also extends to higher ages where OA loss dominates. The mass added at low

  20. Flow monitoring and control system for injection wells

    DOEpatents

    Corey, John C.

    1993-01-01

    A system for monitoring and controlling the injection rate of fluid by an injection well of an in-situ remediation system for treating a contaminated groundwater plume. The well is fitted with a gated insert, substantially coaxial with the injection well. A plurality of openings, some or all of which are equipped with fluid flow sensors and gates, are spaced along the insert. The gates and sensors are connected to a surface controller. The insert may extend throughout part of, or substantially the entire length of the injection well. Alternatively, the insert may comprise one or more movable modules which can be positioned wherever desired along the well. The gates are opened part-way at the start of treatment. The sensors monitor and display the flow rate of fluid passing through each opening on a controller. As treatment continues, the gates are opened to increase flow in regions of lesser flow, and closed to decrease flow in regions of greater flow, thereby approximately equalizing the amount of fluid reaching each part of the plume.

  1. Flow monitoring and control system for injection wells

    DOEpatents

    Corey, J.C.

    1993-02-16

    A system for monitoring and controlling the injection rate of fluid by an injection well of an in-situ remediation system for treating a contaminated groundwater plume. The well is fitted with a gated insert, substantially coaxial with the injection well. A plurality of openings, some or all of which are equipped with fluid flow sensors and gates, are spaced along the insert. The gates and sensors are connected to a surface controller. The insert may extend throughout part of, or substantially the entire length of the injection well. Alternatively, the insert may comprise one or more movable modules which can be positioned wherever desired along the well. The gates are opened part-way at the start of treatment. The sensors monitor and display the flow rate of fluid passing through each opening on a controller. As treatment continues, the gates are opened to increase flow in regions of lesser flow, and closed to decrease flow in regions of greater flow, thereby approximately equalizing the amount of fluid reaching each part of the plume.

  2. Aerosol delivery of programmed cell death protein 4 using polysorbitol-based gene delivery system for lung cancer therapy.

    PubMed

    Kim, You-Kyoung; Xing, Lei; Chen, Bao-An; Xu, Fengguo; Jiang, Hu-Lin; Zhang, Can

    2014-11-01

    The development of a safe and effective gene delivery system is the most challenging obstacle to the broad application of gene therapy in the clinic. In this study, we report the development of a polysorbitol-based gene delivery system as an alternative gene carrier for lung cancer therapy. The copolymer was prepared by a Michael addition reaction between sorbitol diacrylate (SD) and spermine (SPE); the SD-SPE copolymer effectively condenses with DNA on the nanoscale and protects it from nucleases. SD-SPE/DNA complexes showed excellent transfection with low toxicity both in vitro and in vivo, and aerosol delivery of SD-SPE complexes with programmed cell death protein 4 DNA significantly suppressed lung tumorigenesis in K-ras(LA1) lung cancer model mice. These results demonstrate that SD-SPE has great potential as a gene delivery system based on its excellent biocompatibility and high gene delivery efficiency for lung cancer gene therapy. PMID:24983766

  3. Multiphase Flow Technology Impacts on Thermal Control Systems for Exploration

    NASA Technical Reports Server (NTRS)

    McQuillen, John; Sankovic, John; Lekan, Jack

    2006-01-01

    The Two-Phase Flow Facility (TPHIFFy) Project focused on bridging the critical knowledge gap by developing and demonstrating critical multiphase fluid products for advanced life support, thermal management and power conversion systems that are required to enable the Vision for Space Exploration. Safety and reliability of future systems will be enhanced by addressing critical microgravity fluid physics issues associated with flow boiling, condensation, phase separation, and system stability. The project included concept development, normal gravity testing, and reduced gravity aircraft flight campaigns, in preparation for the development of a space flight experiment implementation. Data will be utilized to develop predictive models that could be used for system design and operation. A single fluid, two-phase closed thermodynamic loop test bed was designed, assembled and tested. The major components in this test bed include: a boiler, a condenser, a phase separator and a circulating pump. The test loop was instrumented with flow meters, thermocouples, pressure transducers and both high speed and normal speed video cameras. A low boiling point surrogate fluid, FC-72, was selected based on scaling analyses using preliminary designs for operational systems. Preliminary results are presented which include flow regime transitions and some observations regarding system stability.

  4. Modeling of flow systems for implementation under KATE

    NASA Technical Reports Server (NTRS)

    Whitlow, Jonathan E.

    1990-01-01

    The modeling of flow systems is a task currently being investigated at Kennedy Space Center in parallel with the development of the KATE artificial intelligence system used for monitoring diagnosis and control. Various aspects of the modeling issues are focussed on with particular emphasis on a water system scheduled for demonstration within the KATE environment in September of this year. LISP procedures were written to solve the continuity equations for three internal pressure nodes using Newton's method for simultaneous nonlinear equations.

  5. Lidar and Laser Technology for NASA'S Cloud-Aerosol Transport System (CATS) Payload on The International Space Station (JEM-EF)

    NASA Astrophysics Data System (ADS)

    Storm, Mark; Stevenson, Gary; Hovis, Floyd; Gavert, William; Dang, Xung; Darab, Abe; Chuang, Ti; Burns, Patrick

    2016-06-01

    This paper describes the ISS lidar technology provided by Fibertek, Inc. in support of the NASA GSFC CATS mission and provides an assessment of the in-flight systems performance and lessons learned. During February the systems successfully operated in space for more than 300 hours using 25 W average power lasers and photon counting of aerosol atmospheric returns.

  6. High-efficiency particulate air filter test stand and aerosol generator for particle loading studies.

    PubMed

    Arunkumar, R; Hogancamp, Kristina U; Parsons, Michael S; Rogers, Donna M; Norton, Olin P; Nagel, Brian A; Alderman, Steven L; Waggoner, Charles A

    2007-08-01

    This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30 x 30 x 29 cm(3) nuclear grade high-efficiency particulate air (HEPA) filters under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5 to 12 standard m(3)/min. Relative humidity levels are controllable from 5%-90% and the temperature of the aerosol stream is variable from ambient to 150 degrees C. Test aerosols are produced through spray drying source material solutions that are introduced into a heated stainless steel evaporation chamber through an air-atomizing nozzle. Regulation of the particle size distribution of the aerosol challenge is achieved by varying source solution concentrations and through the use of a postgeneration cyclone. The aerosol generation system is unique in that it facilitates the testing of standard HEPA filters at and beyond rated media velocities by consistently providing, into a nominal flow of 7 standard m(3)/min, high mass concentrations (approximately 25 mg/m(3)) of dry aerosol streams having count mean diameters centered near the most penetrating particle size for HEPA filters (120-160 nm). Aerosol streams that have been generated and characterized include those derived from various concentrations of KCl, NaCl, and sucrose solutions. Additionally, a water insoluble aerosol stream in which the solid component is predominantly iron (III) has been produced. Multiple ports are available on the test stand for making simultaneous aerosol measurements upstream and downstream of the test filter. Types of filter performance related studies that can be performed using this test stand system include filter lifetime studies, filtering efficiency testing, media velocity testing, evaluations under high mass loading and high humidity conditions, and determination of the downstream particle size distributions. PMID

  7. High-efficiency particulate air filter test stand and aerosol generator for particle loading studies

    NASA Astrophysics Data System (ADS)

    Arunkumar, R.; Hogancamp, Kristina U.; Parsons, Michael S.; Rogers, Donna M.; Norton, Olin P.; Nagel, Brian A.; Alderman, Steven L.; Waggoner, Charles A.

    2007-08-01

    This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30×30×29cm3 nuclear grade high-efficiency particulate air (HEPA) filters under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5to12standardm3/min. Relative humidity levels are controllable from 5%-90% and the temperature of the aerosol stream is variable from ambient to 150°C. Test aerosols are produced through spray drying source material solutions that are introduced into a heated stainless steel evaporation chamber through an air-atomizing nozzle. Regulation of the particle size distribution of the aerosol challenge is achieved by varying source solution concentrations and through the use of a postgeneration cyclone. The aerosol generation system is unique in that it facilitates the testing of standard HEPA filters at and beyond rated media velocities by consistently providing, into a nominal flow of 7standardm3/min, high mass concentrations (˜25mg/m3) of dry aerosol streams having count mean diameters centered near the most penetrating particle size for HEPA filters (120-160nm). Aerosol streams that have been generated and characterized include those derived from various concentrations of KCl, NaCl, and sucrose solutions. Additionally, a water insoluble aerosol stream in which the solid component is predominantly iron (III) has been produced. Multiple ports are available on the test stand for making simultaneous aerosol measurements upstream and downstream of the test filter. Types of filter performance related studies that can be performed using this test stand system include filter lifetime studies, filtering efficiency testing, media velocity testing, evaluations under high mass loading and high humidity conditions, and determination of the downstream particle size distributions.

  8. Shock-induced turbulent flow in baffle systems

    SciTech Connect

    Kuhl, A.L.; Reichenbach, H.

    1993-07-01

    Experiments are described on shock propagation through 2-D aligned and staggered baffle systems. Flow visualization was provided by shadow and schlieren photography, recorded by the Cranz-Schardin camera. Also single-frame, infinite-fringe, color interferograms were used. Intuition suggests that this is a rather simple 2-D shock diffraction problem. However, flow visualization reveals that the flow rapidly evolved into a complex 3-D turbulent mixing problem. Mushroom-shaped mixing regions blocked the flow into the next baffle orifice. Thus energy was transferred from the directed kinetic energy (induced by the shock) to rotational energy of turbulent mixing, and then dissipated by molecular effects. These processes dramatically dissipate the strength of the shock wave. The experiments provide an excellent test case that could be used to assess the accuracy of computer code calculations of such problems.

  9. Lockheed laminar-flow control systems development and applications

    NASA Technical Reports Server (NTRS)

    Lange, Roy H.

    1987-01-01

    Progress is summarized from 1974 to the present in the practical application of laminar-flow control (LFC) to subsonic transport aircraft. Those efforts included preliminary design system studies of commercial and military transports and experimental investigations leading to the development of the leading-edge flight test article installed on the NASA JetStar flight test aircraft. The benefits of LFC on drag, fuel efficiency, lift-to-drag ratio, and operating costs are compared with those for turbulent flow aircraft. The current activities in the NASA Industry Laminar-Flow Enabling Technologies Development contract include summaries of activities in the Task 1 development of a slotted-surface structural concept using advanced aluminum materials and the Task 2 preliminary conceptual design study of global-range military hybrid laminar flow control (HLFC) to obtain data at high Reynolds numbers and at Mach numbers representative of long-range subsonic transport aircraft operation.

  10. Flow Analysis of X-34 Main Propulsion System Feedlines

    NASA Technical Reports Server (NTRS)

    Vu, Bruce; Garcia, Robert

    2000-01-01

    The X-34 Main Propulsion System (MPS) configuration includes the liquid oxygen (LOX) and rocket propellant #1 (RP-1) feedlines. The flow analyses of these feedlines were performed and documented in previous studies. These analyses predicted a relatively low inlet distortion and nearly even flow split at the engine interface. The new design for these MPS feedlines has been recommended recently. The new configuration includes a tighter radius in the RP-1 feedline and a neck-down section between the gimbals. Conversely, the LOX feedline is very similar to the previous design. There were concerns that this new RP-1 configuration might generate a greater flow distortion at the engine interface than the original design. To resolve this issue, a Computation Fluid Dynamics (CFD) analysis was conducted to determine the flow Field in the new RP-1 feedlines.

  11. Parametric retrieval model for estimating aerosol size distribution via the AERONET, LAGOS station.

    PubMed

    Emetere, Moses Eterigho; Akinyemi, Marvel Lola; Akin-Ojo, Omololu

    2015-12-01

    The size characteristics of atmospheric aerosol over the tropical region of Lagos, Southern Nigeria were investigated using two years of continuous spectral aerosol optical depth measurements via the AERONET station for four major bands i.e. blue, green, red and infrared. Lagos lies within the latitude of 6.465°N and longitude of 3.406°E. Few systems of dispersion model was derived upon specified conditions to solve challenges on aerosols size distribution within the Stokes regime. The dispersion model was adopted to derive an aerosol size distribution (ASD) model which is in perfect agreement with existing model. The parametric nature of the formulated ASD model shows the independence of each band to determine the ASD over an area. The turbulence flow of particulates over the area was analyzed using the unified number (Un). A comparative study via the aid of the Davis automatic weather station was carried out on the Reynolds number, Knudsen number and the Unified number. The Reynolds and Unified number were more accurate to describe the atmospheric fields of the location. The aerosols loading trend in January to March (JFM) and August to October (ASO) shows a yearly 15% retention of aerosols in the atmosphere. The effect of the yearly aerosol retention can be seen to partly influence the aerosol loadings between October and February. PMID:26452005

  12. Rotation of a rod system containing inertial fluid flow

    NASA Astrophysics Data System (ADS)

    Sergeev, A. D.

    2012-11-01

    This paper considers a rod system for which it is possible to correctly formulate and solve the problem of three-dimensional motion in the physical space of an elastic pipeline area containing inertial incompressible fluid flow. The precession of the axis of an elastic pipeline along which inertial incompressible fluid flows is described, a physical phenomenon which has not been previously studied. With the use of rigid body dynamics, it was theoretically established that a three-dimensional dynamic process is possible in an open (exchanging mass with the environment) elastic-inertial rod system.

  13. Investigation of aerosol distribution patterns and its optical properties at different time scale by using LIDAR system and AERONET

    NASA Astrophysics Data System (ADS)

    Tan, Fuyi; Khor, Wei Ying; Hee, Wan Shen; Choon, Yeap Eng; San, Lim Hwee; Abdullah, Khiruddin

    2015-04-01

    Atmospheric aerosol is a major health-impairment issue in Malaysia especially during southeast monsoon period (June-September) due to the active open burning activities. However, hazy days were an issue in Penang, Malaysia during March, 2014. Haze intruded Penang during March and lasted for a month except for the few days after rain. Rain water had washed out the aerosols from the atmosphere. Therefore, this study intends to analyse the aerosol profile and the optical properties of aerosol during this haze event and after rain. Meanwhile, several days after the haze event (during April, 2014) were also analyzed for comparison purposes. Additionally, the dominant aerosol type (i.e., dust, biomass burning, industrial and urban, marine, and mixed aerosol) during the study period was identified according to the scattering plots of the aerosol optical depth (AOD) against the Angstrom exponent.

  14. Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

    DOE PAGESBeta

    Ortega, Amber M.; Hayes, Patrick L.; Peng, Zhe; Palm, Brett B.; Hu, Weiwei; Day, Douglas A.; Li, Rui; Cubison, Michael J.; Brune, William H.; Graus, Martin; et al

    2016-06-15

    Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA) that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR) was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS) alternated sampling ambient andmore » reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days–6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA) from aging showed a maximum net SOA production between 0.8–6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH ~ 0.3 day) SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs) in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope ~ –0.65). Oxidation state of carbon (OSc) in reactor SOA increased steeply with age and remained elevated (OSC ~ 2) at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background) vs. photochemical age is similar to previous studies at low to moderate ages and

  15. Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

    NASA Astrophysics Data System (ADS)

    Ortega, Amber M.; Hayes, Patrick L.; Peng, Zhe; Palm, Brett B.; Hu, Weiwei; Day, Douglas A.; Li, Rui; Cubison, Michael J.; Brune, William H.; Graus, Martin; Warneke, Carsten; Gilman, Jessica B.; Kuster, William C.; de Gouw, Joost; Gutiérrez-Montes, Cándido; Jimenez, Jose L.

    2016-06-01

    Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA) that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR) was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS) alternated sampling ambient and reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days-6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA) from aging showed a maximum net SOA production between 0.8-6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH ˜ 0.3 day) SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs) in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope ˜ -0.65). Oxidation state of carbon (OSc) in reactor SOA increased steeply with age and remained elevated (OSC ˜ 2) at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background) vs. photochemical age is similar to previous studies at low to moderate ages and also extends to

  16. Why Is Improvement of Earth System Models so Elusive? Challenges and Strategies from Dust Aerosol Modeling

    NASA Technical Reports Server (NTRS)

    Miller, Ronald L.; Garcia-Pando, Carlos Perez; Perlwitz, Jan; Ginoux, Paul

    2015-01-01

    Past decades have seen an accelerating increase in computing efficiency, while climate models are representing a rapidly widening set of physical processes. Yet simulations of some fundamental aspects of climate like precipitation or aerosol forcing remain highly uncertain and resistant to progress. Dust aerosol modeling of soil particles lofted by wind erosion has seen a similar conflict between increasing model sophistication and remaining uncertainty. Dust aerosols perturb the energy and water cycles by scattering radiation and acting as ice nuclei, while mediating atmospheric chemistry and marine photosynthesis (and thus the carbon cycle). These effects take place across scales from the dimensions of an ice crystal to the planetary-scale circulation that disperses dust far downwind of its parent soil. Representing this range leads to several modeling challenges. Should we limit complexity in our model, which consumes computer resources and inhibits interpretation? How do we decide if a process involving dust is worthy of inclusion within our model? Can we identify a minimal representation of a complex process that is efficient yet retains the physics relevant to climate? Answering these questions about the appropriate degree of representation is guided by model evaluation, which presents several more challenges. How do we proceed if the available observations do not directly constrain our process of interest? (This could result from competing processes that influence the observed variable and obscure the signature of our process of interest.) Examples will be presented from dust modeling, with lessons that might be more broadly applicable. The end result will either be clinical depression or there assuring promise of continued gainful employment as the community confronts these challenges.

  17. Code System to Calculate Tornado-Induced Flow Material Transport.

    1999-11-18

    Version: 00 TORAC models tornado-induced flows, pressures, and material transport within structures. Its use is directed toward nuclear fuel cycle facilities and their primary release pathway, the ventilation system. However, it is applicable to other structures and can model other airflow pathways within a facility. In a nuclear facility, this network system could include process cells, canyons, laboratory offices, corridors, and offgas systems. TORAC predicts flow through a network system that also includes ventilation systemmore » components such as filters, dampers, ducts, and blowers. These ventilation system components are connected to the rooms and corridors of the facility to form a complete network for moving air through the structure and, perhaps, maintaining pressure levels in certain areas. The material transport capability in TORAC is very basic and includes convection, depletion, entrainment, and filtration of material.« less

  18. Preliminary aerosol generator design studies

    NASA Technical Reports Server (NTRS)

    Stampfer, J. F., Jr.

    1976-01-01

    The design and construction of a prototype vaporization generator for highly dispersed sodium chloride aerosols is described. The aerosol generating system is to be used in the Science Simulator of the Cloud Physics Laboratory Project and as part of the Cloud Physics Laboratory payload to be flown on the shuttle/spacelab.

  19. Laboratory studies of interaction between trace gases and sulphuric acid or sulphate aerosols using flow-tube reactors

    NASA Astrophysics Data System (ADS)

    Leu, Ming-Taun

    Stratospheric ozone provides a protective shield for humanity and the global biosphere from harmful ultraviolet solar radiation. In past decades, theoretical models for the calculation of ozone balance frequently used gas-phase reactions alone in their studies. Since the discovery of the Antarctic ozone hole in 1985, however, it has been demonstrated that knowledge of heterogeneous reactions is needed to understand this significant natural event owing to the anthropogenic emission of chlorofluorocarbons. In this review I will briefly discuss the experimental techniques for the research of heterogeneous chemistry carried out in our laboratory. These experimental instruments include flow-tube reactors, an electron-impact ionization mass spectrometer, a chemical ionization mass spectrometer and a scanning mobility particle spectrometer. Numerous measurements of uptake coefficient (or reaction probability) and solubility of trace gases in liquid sulphuric acid have been performed under the ambient conditions in the upper troposphere and lower stratosphere, mainly 190-250 K and 40-80 wt% of H

  20. Multiple well systems with non-Darcy flow.

    PubMed

    Mijic, Ana; Mathias, Simon A; LaForce, Tara C

    2013-01-01

    Optimization of groundwater and other subsurface resources requires analysis of multiple-well systems. The usual modeling approach is to apply a linear flow equation (e.g., Darcy's law in confined aquifers). In such conditions, the composite response of a system of wells can be determined by summating responses of the individual wells (the principle of superposition). However, if the flow velocity increases, the nonlinear losses become important in the near-well region and the principle of superposition is no longer valid. This article presents an alternative method for applying analytical solutions of non-Darcy flow for a single- to multiple-well systems. The method focuses on the response of the central injection well located in an array of equally spaced wells, as it is the well that exhibits the highest pressure change within the system. This critical well can be represented as a single well situated in the center of a closed square domain, the width of which is equal to the well spacing. It is hypothesized that a single well situated in a circular region of the equivalent plan area adequately represents such a system. A test case is presented and compared with a finite-difference solution for the original problem, assuming that the flow is governed by the nonlinear Forchheimer equation. PMID:23039097

  1. Global Aerosols

    Atmospheric Science Data Center

    2013-04-19

    ... sizes and from multiple sources, including biomass burning, mineral dust, sea salt and regional industrial pollution. A color scale is ... desert source region. Deserts are the main sources of mineral dust, and MISR obtains aerosol optical depth at visible wavelengths ...

  2. The Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study (SOCRATES): An Observational Campaign for Determining Role of Clouds, Aerosols and Radiation in Climate System

    NASA Astrophysics Data System (ADS)

    McFarquhar, G. M.; Wood, R.; Bretherton, C. S.; Alexander, S.; Jakob, C.; Marchand, R.; Protat, A.; Quinn, P.; Siems, S. T.; Weller, R. A.

    2014-12-01

    The Southern Ocean (SO) region is one of the cloudiest on Earth, and as such clouds determine its albedo and play a major role in climate. Evidence shows Earth's climate sensitivity and the Intertropical Convergence Zone location depend upon SO clouds. But, climate models are challenged by uncertainties and biases in the simulation of clouds, aerosols, and air-sea exchanges in this region which trace back to a poor process-level understanding. Due to the SO's remote location, there have been sparse observations of clouds, aerosols, precipitation, radiation and the air-sea interface apart from those from satellites. Plans for an upcoming observational program, SOCRATES, are outlined. Based on feedback on observational and modeling requirements from a 2014 workshop conducted at the University of Washington, a plan is described for obtaining a comprehensive dataset on the boundary-layer structure and associated vertical distributions of liquid and mixed-phase cloud and aerosol properties across a range of synoptic settings, especially in the cold sector of cyclonic storms. Four science themes are developed: improved climate model simulation of SO cloud and boundary layer structure in a rapidly varying synoptic setting; understanding seasonal and synoptic variability in SO cloud condensation and ice nucleus concentration and the role of local biogenic sources; understanding supercooled liquid and mixed-phase clouds and their impacts; and advancing retrievals of clouds, precipitation, aerosols, radiation and surface fluxes. Testable hypotheses for each theme are identified. The observational strategy consists of long-term ground-based observations from Macquarie Island and Davis, continuous data collection onboard Antarctic supply ships, satellite retrievals, and a dedicated field campaign covering 2 distinct seasons using in-situ and remote sensors on low- and high-altitude aircraft, UAVs, and a ship-borne platform. A timeline for these activities is proposed.

  3. Mathematical modelling of flow distribution in the human cardiovascular system

    NASA Technical Reports Server (NTRS)

    Sud, V. K.; Srinivasan, R. S.; Charles, J. B.; Bungo, M. W.

    1992-01-01

    The paper presents a detailed model of the entire human cardiovascular system which aims to study the changes in flow distribution caused by external stimuli, changes in internal parameters, or other factors. The arterial-venous network is represented by 325 interconnected elastic segments. The mathematical description of each segment is based on equations of hydrodynamics and those of stress/strain relationships in elastic materials. Appropriate input functions provide for the pumping of blood by the heart through the system. The analysis employs the finite-element technique which can accommodate any prescribed boundary conditions. Values of model parameters are from available data on physical and rheological properties of blood and blood vessels. As a representative example, simulation results on changes in flow distribution with changes in the elastic properties of blood vessels are discussed. They indicate that the errors in the calculated overall flow rates are not significant even in the extreme case of arteries and veins behaving as rigid tubes.

  4. RAZOR EX Anthrax Air Detection System for detection of Bacillus anthracis spores from aerosol collection samples: collaborative study.

    PubMed

    Hadfield, Ted; Ryan, Valorie; Spaulding, Usha K; Clemens, Kristine M; Ota, Irene M; Brunelle, Sharon L

    2013-01-01

    The RAZOR EX Anthrax Air Detection System was validated in a collaborative study for the detection of Bacillus anthracis in aerosol collection buffer. Phosphate-buffered saline was charged with 1 mg/mL standardized dust to simulate an authentic aerosol collection sample. The dust-charged buffer was spiked with either B. anthracis Ames at 2000 spores/mL or Bacillus cereus at 20 000 spores/mL. Twelve collaborators participated in the study, with four collaborators at each of three sites. Each collaborator tested 12 replicates of B. anthracis in dust-charged buffer and 12 replicates of B. cereus in dust-charged buffer. All samples sets were randomized and blind-coded. All collaborators produced valid data sets (no collaborators displayed systematic errors) and there was only one invalid data point. After unblinding, the analysis revealed a cross-collaborator probability of detection (CPOD) of 1.00 (144 positive results from 144 replicates, 95% confidence interval 0.975-1.00) for the B. anthracis samples and a CPOD of 0.00 (0 positive results from 143 replicates, 95% confidence interval 0.00-0.0262) for the B. cereus samples. These data meet the requirements of AOAC Standard Method Performance Requirement 2010.003, developed by the Stakeholder Panel on Agent Detection Assays. PMID:23767365

  5. A windowless flow cell-based miniaturized fluorescence detector for capillary flow systems.

    PubMed

    Xu, Jing; Yang, Bing-Cheng; Tian, Hong-Zhe; Guan, Ya-Feng

    2006-04-01

    A miniaturized fluorescence detector utilizing a three-dimensional windowless flow cell has been constructed and evaluated. The inlet and outlet liquid channels are collinear and are located in the same plane as the excitation paths, while the optical fiber used to collect the emission light is perpendicular to this plane. The straightforward arrangement of the flow path minimizes band dispersion and eliminates bubble formation or accumulation inside the cell. The use of high-brightness light-emitting diodes (LEDs) as the excitation source and a miniaturized metal package photomultiplier tube (PMT) results in a compact and sensitive fluorescence detector. The detection limit obtained from the system for fluorescein isothiocyanate (FITC) in flow injection mode is 2.6 nmol/L. The analysis of riboflavin and FITC by packed capillary liquid chromatography is demonstrated. PMID:16547742

  6. Improvement in Clouds and the Earth's Radiant Energy System/Surface and Atmosphere Radiation Budget Dust Aerosol Properties, Effects on Surface Validation of Clouds and Radiative Swath

    SciTech Connect

    Rutan, D.; Rose, F.; Charlock, T.P.

    2005-03-18

    Within the Clouds and the Earth's Radiant Energy System (CERES) science team (Wielicki et al. 1996), the Surface and Atmospheric Radiation Budget (SARB) group is tasked with calculating vertical profiles of heating rates, globally, and continuously, beneath CERES footprint observations of Top of Atmosphere (TOA) fluxes. This is accomplished using a fast radiative transfer code originally developed by Qiang Fu and Kuo-Nan Liou (Fu and Liou 1993) and subsequently highly modified by the SARB team. Details on the code and its inputs can be found in Kato et al. (2005) and Rose and Charlock (2002). Among the many required inputs is characterization of the vertical column profile of aerosols beneath each footprint. To do this SARB combines aerosol optical depth information from the moderate-resolution imaging spectroradiometer (MODIS) instrument along with aerosol constituents specified by the Model for Atmosphere and Chemical Transport (MATCH) of Collins et al. (2001), and aerosol properties (e.g. single scatter albedo and asymmetry parameter) from Tegen and Lacis (1996) and OPAC (Hess et al. 1998). The publicly available files that include these flux profiles, called the Clouds and Radiative Swath (CRS) data product, available from the Langley Atmospheric Sciences Data Center (http://eosweb.larc.nasa.gov/). As various versions of the code are completed, publishable results are named ''Editions.'' After CRS Edition 2A was finalized it was found that dust aerosols were too absorptive. Dust aerosols have subsequently been modified using a new set of properties developed by Andy Lacis and results have been released in CRS Edition 2B. This paper discusses the effects of changing desert dust aerosol properties, which can be significant for the radiation budget in mid ocean, a few thousand kilometers from the source regions. Resulting changes are validated via comparison of surface observed fluxes from the Saudi Solar Village surface site (Myers et al. 1999), and the E13 site

  7. Low power acoustic harvesting of aerosols

    SciTech Connect

    Kaduchak, G.; Sinha, D. N.

    2001-01-01

    A new acoustic device for levitation and/or concentration of aerosols and sniall liquid/solid samples (up to several millimeters in diameter) in air has been developed. The device is inexpensive, low-power, and, in its simplest embodiment, does not require accurate alignmen1 of a resonant cavity. It is constructed from a cylindrical PZT tube of outside diameter D = 19.0 mm and thickness-to-radius ratio h/a - 0.03. The lowest-order breathing mode of the tube is tuned to match a resonant mode of the interior air-filled cylindrical cavity. A high Q cavity results that can be driven efficiently. An acoustic standing wave is created in the inteirior cavity of the cylindrical shell where particle concrmtration takes place at the nodal planes of the field. It is shown that drops of water in excess of 1 mm in diameter may be levitated against the force of gravity for approxirnately 100 mW of input electrical power. The main objective of the research is to implement this lowpower device to concentrate and harvest aerosols in a flowing system. Several different cavity geonietries iwe presented for efficient collection of 1 he conaartratetl aerosols. Concentraiion factors greater than 40 iue demonstrated for particles of size 0.7 1.1 in a flow volume of 50 L/minute.

  8. Variability in Nose-to-Lung Aerosol Delivery

    PubMed Central

    Walenga, Ross L; Tian, Geng; Hindle, Michael; Yelverton, Joshua; Dodson, Kelley; Longest, P. Worth

    2014-01-01

    Nasal delivery of lung targeted pharmaceutical aerosols is ideal for drugs that need to be administered during high flow nasal cannula (HFNC) gas delivery, but based on previous studies losses and variability through both the delivery system and nasal cavity are expected to be high. The objective of this study was to assess the variability in aerosol delivery through the nose to the lungs with a nasal cannula interface for conventional and excipient enhanced growth (EEG) delivery techniques. A database of nasal cavity computed tomography (CT) scans was collected and analyzed, from which four models were selected to represent a wide range of adult anatomies, quantified based on the nasal surface area-to-volume ratio (SA/V). Computational fluid dynamics (CFD) methods were validated with existing in vitro data and used to predict aerosol delivery through a streamlined nasal cannula and the four nasal models at a steady state flow rate of 30 L/min. Aerosols considered were solid particles for EEG delivery (initial 0.9 μm and 1.5 μm aerodynamic diameters) and conventional droplets (5 μm) for a control case. Use of the EEG approach was found to reduce depositional losses in the nasal cavity by an order of magnitude and substantially reduce variability. Specifically, for aerosol deposition efficiency in the four geometries, the 95% confidence intervals (CI) for 0.9 and 5 μm aerosols were 2.3-3.1 and 15.5-66.3%, respectively. Simulations showed that the use of EEG as opposed to conventional methods improved delivered dose of aerosols through the nasopharynx, expressed as penetration fraction (PF), by approximately a factor of four. Variability of PF, expressed by the coefficient of variation (CV), was reduced by a factor of four with EEG delivery compared with the control case. Penetration fraction correlated well with SA/V for larger aerosols, but smaller aerosols showed some dependence on nasopharyngeal exit hydraulic diameter. In conclusion, results indicated that

  9. Modeling of metallic aerosol formation in a multicomponent system at high temperatures using a discrete-sectional model. Appendix 7

    SciTech Connect

    1997-02-01

    A multicomponent discrete-sectional model was used to simulate the fate of lead in a high temperature system. The results show the ability of the developed model to simulate metallic aerosol systems at high temperatures. The PbO reaction and nucleation rate can be determined by comparing the simulations and the experimental data. Condensation on SiO{sub 2} particle surfaces is found important for removing the PbO vapor. The value of the accommodation factor that is applied to account for nonidealities in the condensation process are determined. The differences between the nanosized particles and the bulk particles are elucidated. The use of such a model helped to understand the effects of various mechanisms in determining the metal oxide vapor concentration profile and in establishing the ultimate particle size distribution.

  10. Biofilm streamers cause rapid clogging of flow systems

    NASA Astrophysics Data System (ADS)

    Shen, Yi; Drescher, Knut; Wingreen, Ned; Bassler, Bonnie; Stone, Howard

    2012-11-01

    Biofilms are antibiotic-resistant, sessile bacterial communities that are found on most surfaces on Earth. In addition to constituting the most abundant form of bacterial life, biofilms also cause chronic and medical device-associated infections. Despite their importance, basic information about how biofilms behave in common ecological environments is lacking. Here we demonstrate that flow through soil-like porous materials, industrial filters, and medical stents dramatically modifies the morphology of Pseudomonas aeruginosa biofilms to form streamers which over time bridge the space between obstacles and corners in non-uniform environments. Using a microfluidic model system we find that, contrary to the accepted paradigm, the accumulation of surface-attached bacterial biofilm has little effect on flow resistance whereas the formation of biofilm streamers causes sudden and rapid clogging. The time at which clogging happens depends on bacterial growth, while the duration of the clogging transition is driven by flow-mediated transport of bacteria to the clogging site. Flow-induced shedding of extracellular matrix from the resident biofilm generates a sieve-like network that catches bacteria flowing by, which add to the network of extracellular matrix, to cause exponentially rapid clogging. We expect these biofilm streamers to be ubiquitous in nature, and to have profound effects on flow through porous materials in environmental, industrial, and medical environments.

  11. Gas-phase chemistry in Oxidation Flow Reactors for the study of secondary organic aerosols systematically examined by modeling

    NASA Astrophysics Data System (ADS)

    Peng, Z.; Day, D. A.; Ortega, A. M.; Hu, W.; Palm, B. B.; Li, R.; De Gouw, J. A.; Brune, W. H.; Jimenez, J. L.

    2014-12-01

    Oxidation Flow Reactors (OFRs) using OH produced from low-pressure Hg lamps at 254 nm (OFR254) or both 185 and 254 nm (OFR185) are commonly used in atmospheric chemistry and other fields. OFR254 requires addition of externally formed O3 since OH is formed mainly from O3 photolysis, while OFR185 does not since OH can also be formed from H2O photolysis. In this study we use a plug-flow kinetic model to investigate OFR properties under a very wide range of conditions applicable to both field and laboratory studies. We show that radical chemistry in OFRs can be characterized as a function of 3 main parameters: UV light intensity, H2O concentration, and total external OH reactivity (e.g. from VOCs, NOx, and SO2). In OFR185, OH exposure is more sensitive to external OH reactivity than in OFR254, because injected O3 in OFR254 greatly promotes the recycling of HO2 to OH, making external perturbations to the radical chemistry less significant. The uncertainties of modeled OH, O3, and H2O2 due to uncertain kinetic parameters are within 40% in most cases. Sensitivity analysis shows that most of the uncertainty is contributed by photolysis and reactions involving OH and HO2, e.g. 2HO2→H2O2+O2 and OH+O3→HO2+O2. Reactants of atmospheric interest are dominantly consumed by OH, except some biogenics that can have substantial contributions from O3. Other highly reactive species (UV photons, O(1D), and O(3P)) only contribute for some species under conditions low H2O concentration and/or high external OH reactivity, which can be avoided by experimental planning. OFR185 and OFR254 are comparable in terms of non-OH oxidants' influence. In OFRs NO is fast oxidized. RO2 fate is similar to that in the atmosphere under low NO conditions. A comprehensive comparison of OFRs with typical environmental chamber studies with UV blacklights and with the atmosphere is also performed. OFRs' key advantages are their short experimental time scales, portability to field sites, and generally good

  12. Exploiting Representation of the Aerosol-Radiation interactions in Climate Systems: Observation-based Analyses and Global Climate Modeling

    NASA Astrophysics Data System (ADS)

    Chen, Y. C.; Li, J.; Lee, W. L.; Diner, D. J.; Garay, M. J.; Kalashnikova, O. V.

    2015-12-01

    Aerosols affect the Earth's climate by perturbing the radiation budget through scattering and absorption of solar radiation and emitting thermal infrared radiation (defined and referred to as aerosol direct effect). At first order, it is essential for a model to realistically represent the distributions of clouds, convection, aerosol profiles and their associated radiative properties (cloud fraction and effective radius), which are critical for simulating Earth's surface energy and water budgets. The representation of aerosols and their radiative properties remains problematic both in retrieval and modeling. Up to now, the representation of aerosol optical depth (AOD) in GCMs is still far from agreement with the observation. We evaluate the aerosol simulations from the 20th century CMIP5 simulations, and investigate the biases in aerosol loadings against observations. AOD and retrieved aerosol types (e.g., sea salt, organic matter, sulfate) from MISR, MODIS, and CALIPSO satellite observations are utilized to compare with model simulated aerosols. The impacts of the biases of modeled AOD and cloud fraction on aerosol direct effects in GCMs will be presented.

  13. Large-scale flow experiments for managing river systems

    USGS Publications Warehouse

    Konrad, C.P.; Olden, J.D.; Lytle, D.A.; Melis, T.S.; Schmidt, J.C.; Bray, E.N.; Freeman, Mary C.; Gido, K.B.; Hemphill, N.P.; Kennard, M.J.; McMullen, L.E.; Mims, M.C.; Pyron, M.; Robinson, C.T.; Williams, J.G.

    2011-01-01

    Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow experiments have both scientific and social value when they help to resolve specific questions about the ecological action of flow with a clear nexus to water policies and decisions. Water managers must integrate new information into operating policies for large-scale experiments to be effective. Modeling and monitoring can be integrated with experiments to analyze long-term ecological responses. Experimental design should include spatially extensive observations and well-defined, repeated treatments. Large-scale flow manipulations are only a part of dam operations that affect river systems. Scientists can ensure that experimental manipulations continue to be a valuable approach for the scientifically based management of river systems. ?? 2011 by American Institute of Biological Sciences. All rights reserved.

  14. Large-scale flow experiments for managing river systems

    USGS Publications Warehouse

    Konrad, Christopher P.; Olden, Julian D.; Lytle, David A.; Melis, Theodore S.; Schmidt, John C.; Bray, Erin N.; Freeman, Mary C.; Gido, Keith B.; Hemphill, Nina P.; Kennard, Mark J.; McMullen, Laura E.; Mims, Meryl C.; Pyron, Mark; Robinson, Christopher T.; Williams, John G.

    2011-01-01

    Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow experiments have both scientific and social value when they help to resolve specific questions about the ecological action of flow with a clear nexus to water policies and decisions. Water managers must integrate new information into operating policies for large-scale experiments to be effective. Modeling and monitoring can be integrated with experiments to analyze long-term ecological responses. Experimental design should include spatially extensive observations and well-defined, repeated treatments. Large-scale flow manipulations are only a part of dam operations that affect river systems. Scientists can ensure that experimental manipulations continue to be a valuable approach for the scientifically based management of river systems.

  15. Flow monitoring and control system for injection wells

    DOEpatents

    Corey, J.C.

    1991-01-01

    The present invention relates to a system for monitoring and controlling the rate of fluid flow from an injection well used for in-situ remediation of contaminated groundwater. The United States Government has rights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the US Department of Energy and Westinghouse Savannah River Company.

  16. Automotive Power Flow System; Auto Mechanics I: 9043.04.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This automotive power flow system course sets the foundation in the theory of operation of the standard and automatic transmission, clutch assemblies, drive-line and rear axle assemblies. This is a one or two quinmester credit course covering 45 clock hours. In the fourth quinmester course in the tenth year, instruction consists of lectures,…

  17. End-to-end modelling of He II flow systems

    NASA Technical Reports Server (NTRS)

    Mord, A. J.; Snyder, H. A.; Newell, D. A.

    1992-01-01

    A practical computer code has been developed which uses the accepted two-fluid model to simulate He II flow in complicated systems. The full set of equations are used, retaining the coupling between the pressure, temperature and velocity fields. This permits modeling He II flow over the full range of conditions, from strongly or weakly driven flow through large pipes, narrow channels and porous media. The system may include most of the components used in modern superfluid flow systems: non-ideal thermomechanical pumps, tapered sections, constrictions, lines with heated side walls and heat exchangers. The model is validated by comparison with published experimental data. It is applied to a complex system to show some of the non-intuitive feedback effects that can occur. This code is ready to be used as a design tool for practical applications of He II. It can also be used for the design of He II experiments and as a tool for comparison of experimental data with the standard two-fluid model.

  18. Nanotechnology and pharmaceutical inhalation aerosols.

    PubMed

    Patel, A R; Vavia, P R

    2007-02-01

    Pharmaceutical inhalation aerosols have been playing a crucial role in the health and well being of millions of people throughout the world for many years. The technology's continual advancement, the ease of use and the more desirable pulmonary-rather-than-needle delivery for systemic dr