Science.gov

Sample records for transport number measurements

  1. Sediment transport measurements: Chapter 5

    USGS Publications Warehouse

    Diplas, P.; Kuhnle, R.; Gray, J.; Glysson, D.; Edwards, T.

    2008-01-01

    Sediment erosion, transport, and deposition in fluvial systems are complex processes that are treated in detail in other sections of this book. Development of methods suitable for the collection of data that contribute to understanding these processes is a still-evolving science. Sediment and ancillary data are fundamental requirements for the proper management of river systems, including the design of structures, the determination of aspects of stream behavior, ascertaining the probable effect of removing an existing structure, estimation of bulk erosion, transport, and sediment delivery to the oceans, ascertaining the long-term usefulness of reservoirs and other public works, tracking movement of solid-phase contaminants, restoration of degraded or otherwise modified streams, and assistance in the calibration and validation of numerical models. This chapter presents techniques for measuring bed-material properties and suspended and bed-load discharges. Well-established and relatively recent, yet adequately tested, sampling equipment and methodologies, with designs that are guided by sound physical and statistical principles, are described. Where appropriate, the theory behind the development of the equipment and guidelines for its use are presented.

  2. Off-Design Reynolds Number Effects for a Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Owens, Lewis R.; Wahls, Richard A.; Rivers, S. Melissa

    2005-01-01

    A high Reynolds number wind tunnel test was conducted to assess Reynolds number effects on the aerodynamic performance characteristics of a realistic, second-generation supersonic transport concept. The tests included longitudinal studies at transonic and low-speed, high-lift conditions across a range of chord Reynolds numbers (8 million to 120 million). Results presented focus on Reynolds number and static aeroelastic sensitivities at Mach 0.30 and 0.90 for a configuration without a tail. Static aeroelastic effects, which mask Reynolds number effects, were observed. Reynolds number effects were generally small and the drag data followed established trends of skin friction as a function of Reynolds number. A more nose-down pitching moment was produced as Reynolds number increased because of an outward movement of the inboard leading-edge separation at constant angles of attack. This study extends the existing Reynolds number database for supersonic transports operating at off-design conditions.

  3. Heat transport measurements in turbulent rotating Rayleigh-Bénard convection

    NASA Astrophysics Data System (ADS)

    Liu, Yuanming; Ecke, Robert E.

    2009-09-01

    We present experimental heat transport measurements of turbulent Rayleigh-Bénard convection with rotation about a vertical axis. The fluid, water with a Prandtl number (?) of about 6, was confined in a cell with a square cross section of 7.3×7.3cm2 and a height of 9.4 cm. Heat transport was measured for Rayleigh numbers 2×105numbers 0transport, the Nusselt number, at fixed dimensional rotation rate ?D , at fixed Ra varying Ta, at fixed Ta varying Ra, and at fixed Rossby number Ro. The scaling of heat transport in the range of 107 to about 109 is roughly 0.29 with a Ro-dependent coefficient or equivalently is also well fit by a combination of power laws of the form aRa1/5+bRa1/3 . The range of Ra is not sufficient to differentiate single power law or combined power-law scaling. The data are roughly consistent with an assumption that the enhancement of heat transport owing to rotation is proportional to the number of vortical structures penetrating the boundary layer. We also compare indirect measures of thermal and Ekman boundary layer thicknesses to assess their potential role in controlling heat transport in different regimes of Ra and Ta.

  4. Reynolds Number Effects on a Supersonic Transport at Transonic Conditions

    NASA Technical Reports Server (NTRS)

    Wahls, R. N.; Owens, L. R.; Rivers, S. M. B.

    2001-01-01

    A High Speed Civil Transport configuration was tested in the National Transonic Facility at the NASA Langley Research Center as part of NASA's High Speed Research Program. The primary purposes of the tests were to assess Reynolds number scale effects and the high Reynolds number aerodynamic characteristics of a realistic, second generation supersonic transport while providing data for the assessment of computational methods. The tests included longitudinal and lateral/directional studies at low speed high-lift and transonic conditions across a range of Reynolds numbers from that available in conventional wind tunnels to near flight conditions. Results are presented which focus on both the Reynolds number and static aeroelastic sensitivities of longitudinal characteristics at Mach 0.90 for a configuration without an empennage.

  5. Heat transport measurements in turbulent rotating Rayleigh-Benard convection

    SciTech Connect

    Ecke, Robert E; Liu, Yuanming

    2008-01-01

    We present experimental heat transport measurements of turbulent Rayleigh-Benard convection with rotation about a vertical axis. The fluid, water with Prandtl number ({sigma}) about 6, was confined in a cell which had a square cross section of 7.3 cm x 7.3 cm and a height of 9.4 cm. Heat transport was measured for Rayleigh numbers 2 x 10{sup 5} < Ra < 5 x 10{sup 8} and Taylor numbers 0 < Ta < 5 x 10{sup 9}. We show the variation of normalized heat transport, the Nusselt number, at fixed dimensional rotation rate {Omega}{sub D}, at fixed Ra varying Ta, at fixed Ta varying Ra, and at fixed Rossby number Ro. The scaling of heat transport in the range 10{sup 7} to about 10{sup 9} is roughly 0.29 with a Ro dependent coefficient or equivalently is also well fit by a combination of power laws of the form a Ra{sup 1/5} + b Ra{sup 1/3} . The range of Ra is not sufficient to differentiate single power law or combined power law scaling. The overall impact of rotation on heat transport in turbulent convection is assessed.

  6. Two phosphonium ionic liquids with high Li(+) transport number.

    PubMed

    Martins, Vitor L; Sanchez-Ramirez, Nédher; Ribeiro, Mauro C C; Torresi, Roberto M

    2015-09-21

    This work presents the physicochemical characterization of two ionic liquids (ILs) with small phosphonium cations, triethylpenthylphosphonium bis(trifluoromethanesulfonyl)imide ([P2225][Tf2N]) and (2-methoxyethyl)trimethylphosphonium bis(trifluoromethanesulfonyl)imide ([P222(201)][Tf2N]), and their mixtures with Li(+). Properties such as the electrochemical window, density, viscosity and ionic conductivity are presented. The diffusion coefficient was obtained using two different techniques, PGSE-NMR and Li electrodeposition with microelectrodes. In addition, the Li(+) transport number was calculated using the PGSE-NMR technique and an electrochemical approach. The use of these three techniques showed that the PGSE-NMR technique underestimates the diffusion coefficient for charged species. The Li(+) transport number was found to be as high as 0.54. Raman spectroscopy and molecular dynamics simulations were used to evaluate the short-range structure of the liquids. These experiments suggested that the interaction between the Li(+) and the Tf2N(-) anion is similar to that seen with other ILs containing the same anion. However, the MD simulations also showed that the Li(+) ions interact differently with the cation containing an alkyl ether chain. The results found in this work suggest that these Li(+) mixtures have promising potential to be applied as electrolytes in batteries. PMID:26272339

  7. Measurement Corner Mass, Moles and Avogadro's Number

    ERIC Educational Resources Information Center

    Todd, Robert M.

    1977-01-01

    Discusses and clarifies the confusion arising from the use of the terms "mass,""volume,""matter,""mole," and "Avogadro's number." Suggests three laboratory activities concerning mass, volume, and number of particles in a given volume. (CS)

  8. Transportable calorimeter measurements of highly enriched uranium

    SciTech Connect

    Rudy, C.; Bracken, D.S.; Staples, P.; Carrillo, L.

    1997-11-01

    A sensitive calorimeter has been combined with a small temperature-controlled water bath to compose a transportable system that is capable of measuring multikilogram quantities of highly enriched uranium (HEU). The sample chamber size, 5 in. in diameter by 10 in. high, is large enough to hold sufficient HEU metal or high-grade scrap to provide a measurable thermal signal. Calorimetric measurements performed on well-characterized material indicate that the thermal power generated by 93% {sup 235}U samples with 1.0% {sup 234}U can be measured with a precision of about 1% (1 sigma) for 4-kg samples. The transportable system consists of a twin-bridge calorimeter installed inside a 55-gal. stainless steel drum filled with water with heating and cooling supplied by a removable thermoelectric module attached to the side. Isotopic measurements using high-resolution gamma-ray measurements of the HEU samples and analysis with the FRAM code were used to determine the isotopic ratios and specific power of the samples. This information was used to transform the measured thermal power into grams of HEU. Because no physical standards are required, this system could be used for the verification of plutonium, {sup 238}Pu heat sources, or large quantities of metal or other high-grade matrix forms of HEU.

  9. 40 CFR 51.213 - Transportation control measures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Transportation control measures. 51.213... Transportation control measures. (a) The plan must contain procedures for obtaining and maintaining data on actual emissions reductions achieved as a result of implementing transportation control measures. (b)...

  10. 40 CFR 51.213 - Transportation control measures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Transportation control measures. 51.213... Transportation control measures. (a) The plan must contain procedures for obtaining and maintaining data on actual emissions reductions achieved as a result of implementing transportation control measures. (b)...

  11. 40 CFR 51.213 - Transportation control measures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Transportation control measures. 51.213... Transportation control measures. (a) The plan must contain procedures for obtaining and maintaining data on actual emissions reductions achieved as a result of implementing transportation control measures. (b)...

  12. Transportable setup for amplifier phase fidelity measurements

    NASA Astrophysics Data System (ADS)

    Tröbs, M.; Bogan, C.; Barke, S.; Kühn, G.; Reiche, J.; Heinzel, G.; Danzmann, K.

    2015-05-01

    One possible laser source for the Laser Interferometer Space Antenna (LISA) consists of an Ytterbium-doped fiber amplifier originally developed for inter-satellite communication, seeded by the laser used for the technology demonstrator mission LISA Pathfinder. LISA needs to transmit clock information between its three spacecraft to correct for phase noise between the clocks on the individual spacecraft. For this purpose phase modulation sidebands at GHz frequencies will be imprinted on the laser beams between spacecraft. Differential phase noise between the carrier and a sideband introduced within the optical chain must be very low. We report on a transportable setup to measure the phase fidelity of optical amplifiers.

  13. Ranking of Intuitionistic Fuzzy Numbers by New Distance Measure

    E-print Network

    Debaroti Das; P. K. De

    2014-10-27

    Ranking of intuitionsitic fuzzy number plays a vital role in decision making and other intuitionistic fuzzy applications. In this paper, we propose a new ranking method of intuitionistic fuzzy number based on distance measure. We first define a distance measure for interval numbers based on Lp metric and further generalize the idea for intuitionistic fuzzy number by forming interval with their respective value and ambiguity indices. Finally, some comparative results are given in tabular form.

  14. Measured Local Heat Transport in Turbulent Rayleigh-Benard Convection X.-D. Shang,1

    E-print Network

    Tong, Penger

    Measured Local Heat Transport in Turbulent Rayleigh-Be´nard Convection X.-D. Shang,1 X.-L. Qiu,2 P September 2002; published 20 February 2003) Local convective heat flux in turbulent thermal convection for the heat transport in turbulent convection. DOI: 10.1103/PhysRevLett.90.074501 PACS numbers: 47.27.Te, 44

  15. Fluid transport at low Reynolds number with magnetically actuated artificial cilia

    E-print Network

    Erik M. Gauger; Matthew Downton; Holger Stark

    2008-11-25

    By numerical modeling we investigate fluid transport in low-Reynolds-number flow achieved with a special elastic filament or artifical cilium attached to a planar surface. The filament is made of superparamagnetic particles linked together by DNA double strands. An external magnetic field induces dipolar interactions between the beads of the filament which provides a convenient way of actuating the cilium in a well-controlled manner. The filament has recently been used to successfully construct the first artificial micro-swimmer [R. Dreyfus at al., Nature 437, 862 (2005)]. In our numerical study we introduce a measure, which we call pumping performance, to quantify the fluid transport induced by the magnetically actuated cilium and identify an optimum stroke pattern of the filament. It consists of a slow transport stroke and a fast recovery stroke. Our detailed parameter study also reveals that for sufficiently large magnetic fields the artificial cilium is mainly governed by the Mason number that compares frictional to magnetic forces. Initial studies on multi-cilia systems show that the pumping performance is very sensitive to the imposed phase lag between neighboring cilia, i.e., to the details of the initiated metachronal wave.

  16. Measurement of hydrocarbon transport in bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the hydrophobic, volatility, and relatively low aqueous solubility of aliphatic and aromatic hydrocarbons, transport of these chemicals by bacteria has not been extensively studied. These issues make transport assays difficult to carry out, and as a result, strong evidence for the active tran...

  17. TRANSPORT PROPERTY MEASUREMENTS OF HFC-236EA

    EPA Science Inventory

    The report gives results of an evaluation of transport properties of 1, 1, 1, 2, 3, 3-hexafluoropropane (HFC-236ea), with liquid viscosity and thermal conductivity being the two main transport properties of interest. In addition, the specific heat and density of refrigerant/lubri...

  18. Measurement of Hydrocarbon Transport in Bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrocarbon uptake by bacteria has not been extensively studied, and strong evidence for active transport of hydrocarbons is lacking. The volatile nature of hydrocarbons, their hydrophobicity, and their relatively low aqueous solubilities can complicate transport assays. Here we present a detailed...

  19. TRANSPORT PROPERTY MEASUREMENTS OF HFC-236EA

    EPA Science Inventory

    The report gives results of an evaluation of transport properties of 1,1,1,2,3,3,-hexafluoropropane (HFC-236ea), with liquid viscosity and thermal conductivity being the two main transport properties of interest. In addition, the specific heat and density of refrigerant/lubrican...

  20. On Measurements, Numbers and p-Adic Mathematical Physics

    E-print Network

    Branko Dragovich

    2012-05-23

    In this short paper I consider relation between measurements, numbers and p-adic mathematical physics. p-Adic numbers are not result of measurements, but nevertheless they play significant role in description of some systems and phenomena. We illustrate their ability for applications referring to some sectors of p-adic mathematical physics and related topics, in particular, to string theory and the genetic code.

  1. Bounds on vertical heat transport for infinite Prandtl number Rayleigh-B\\'enard convection

    E-print Network

    Rheinisch-Westfälische Technische Hochschule Aachen (RWTH)

    Bounds on vertical heat transport for infinite Prandtl number Rayleigh- B\\'enard convection Journal of the Boussinesq equations, the enhancement of vertical heat transport in Rayleigh-B´enard convection, the Nusselt and astrophysics. Rayleigh-B´enard convection, where a fluid layer between rigid plates is heated from below

  2. Measurement of tracheal mucous transport rate in the horse

    SciTech Connect

    Nelson, R.; Hampe, D.W.

    1983-06-01

    Tracheal mucous transport rates were measured in 12 nonanesthetized horses after an intratracheal injection of 99mtechnetium-sulfur colloid. The transport rate of the subsequent bolus of radioactivity was determined, using a portable scaler rate meter fitted with a high-energy gamma-scintillation probe. A gamma-scintillation camera was used to verify bolus form and movement in 1 horse. The mean tracheal mucous transport rate was 1.66 +/- 0.24 cm/min.

  3. Overview of mitigation policies and measures in transportation

    SciTech Connect

    Ernst, J.

    1996-12-31

    In this paper the author looks at the general question of what can be done in the transportation sector to address the problem of greenhouse gas emissions. Obviously, fewer vehicles is less emission. But on a global scale he reviews the population growth in major cities, the type of transport employed, the correlation of vehicle ownership and gross national product, as well as the costs, direct and indirect of letting more personal wealth drive one to personal vehicles as a way to transport oneself to work. The increased speed comes with many costs for the individual and for society. The development of mass transportation systems provides a number of benefits, in the form of urban development, less reliance on imported fuels, transport system health, general health and productivity of work force, and reduced costs to government to support transportation systems.

  4. A rain splash transport equation assimilating field and laboratory measurements

    E-print Network

    Mudd, Simon Marius

    A rain splash transport equation assimilating field and laboratory measurements Thomas Dunne,1 equations relating sediment flux to its major controls. An equation for rain splash transport in the absence. The equation relates rain splash to hillslope gradient, the median raindrop diameter of a storm, and ground

  5. Numerical Upscaling of Transport Through Obstructed Regions Over a Broad Range of Reynolds Numbers

    NASA Astrophysics Data System (ADS)

    Sund, N. L.; Bolster, D.; Mattis, S. A.

    2014-12-01

    While historically flow and transport in porous media has focused on low Reynolds number and Peclet number regimes there are a variety of examples relevant to environmental fluid dynamics where higher Reynolds number flows are important. A common example might include flow and transport through wetlands where plants act as the solid phase of an effective porous medium. In particular, heterogeneity in the flow field due to presence of the solid phases gives rise to complex transport and mixing behaviors that cannot be upscaled at pre-asymptotic times using conventional approaches. We numerically simulate pore-scale flow and transport through obstructed domains over a range of Reynolds numbers from 15 to 280 and then upscale transport. We upscale using a correlated continuous time random walk (correlated CTRW) model, originally introduced in [1]. We then assess the correlated CTRW's ability to predict observables for both asymptotic and pre-asymptotic time scales and compare our results to those of a classical CTRW to determine when velocity correlations must be accounted for. REFERENCES[1] T.L. Borgne, M. Dentz, J. Carrera: Lagrangian statistical model for transport in highly heterogeneous velocity fields, Physical Review Letters 101 (2008) 090601.

  6. 41 CFR 102-117.270 - What are agency performance measures for transportation?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... false What are agency performance measures for transportation? 102-117.270...117-TRANSPORTATION MANAGEMENT Performance Measures § 102-117.270 What are agency performance measures for transportation? (a) Agency...

  7. 41 CFR 102-117.270 - What are agency performance measures for transportation?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... false What are agency performance measures for transportation? 102-117.270...117-TRANSPORTATION MANAGEMENT Performance Measures § 102-117.270 What are agency performance measures for transportation? (a) Agency...

  8. 41 CFR 102-117.270 - What are agency performance measures for transportation?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... false What are agency performance measures for transportation? 102-117.270...117-TRANSPORTATION MANAGEMENT Performance Measures § 102-117.270 What are agency performance measures for transportation? (a) Agency...

  9. 41 CFR 102-117.270 - What are agency performance measures for transportation?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... false What are agency performance measures for transportation? 102-117.270...117-TRANSPORTATION MANAGEMENT Performance Measures § 102-117.270 What are agency performance measures for transportation? (a) Agency...

  10. 41 CFR 102-117.270 - What are agency performance measures for transportation?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... false What are agency performance measures for transportation? 102-117.270...117-TRANSPORTATION MANAGEMENT Performance Measures § 102-117.270 What are agency performance measures for transportation? (a) Agency...

  11. Nanoscale thermal transport measurements: Bridging ultrafast and steady-state

    NASA Astrophysics Data System (ADS)

    Green, Brian; Siemens, Mark; Sarah Mason Collaboration; Barry Zink Collaboration

    2014-03-01

    Macroscale thermal transport is explained by classical thermal diffusion, but as nanostructure length scales are reduced towards the order of the phonon mean free path, transport of thermal energy takes on a fundamentally different character. Nanoscale effects emerge such as sensitivity to the presence of surfaces and the onset of ballistic transport. We investigate nanoscale thermal physics by comparing results from two different transport measurement techniques applied to systems of highly confined thermal transport: metallic thin films deposited on a suspended bridge structure. One technique uses the transient thermoreflectance (TTR) method to measure picosecond cooling dynamics following ultrafast laser heating in a micron-sized region of the metallic film deposited on the bridge; the second is a DC technique that measures transport driven by an Ohmically-generated thermal gradient across the bridge through the full volume of the film. We find that these very different methods give similar results of significantly reduced thermal conductivity relative to macroscale values. We compare TTR and DC results between differing film thicknesses, and evaluate conductance uniformity across film surfaces. In combination, the TTR and DC methods are powerful tools for investigating and understanding thermal transport at the nanoscale. ACS Petroleum Research Fund.

  12. Transported acid aerosols measured in southern Ontario

    NASA Astrophysics Data System (ADS)

    Keeler, Gerald J.; Spengler, John D.; Koutrakis, Petros; Allen, George A.; Raizenne, Mark; Stern, Bonnie

    During the period 29 June 1986-9 August 1986, a field health study assessing the acute health effects of air pollutants on children was conducted at a summer girls' camp on the northern shore of Lake Erie in SW Ontario. Continuous air pollution measurements of SO 2, O 3, NO x, particulate sulfates, light scattering, and meteorological measurements including temperature, dew point, and wind speed and direction were made. Twelve-hour integrated samples of size fractioned particles were also obtained using dichotomous samplers and Harvard impactors equipped with an ammonia denuder for subsequent hydrogen ion determination. Particulate samples were analyzed for trace elements by X-ray fluorescence and Neutron Activation, and for organic and elemental carbon by a thermal/optical technique. The measured aerosol was periodically very acidic with observed 12-h averaged H + concentrations in the range < 10-560 nmoles m -3. The aerosol H + appeared to represent the net strong acidity after H 2SO 4 reaction with NH 3(g). Average daytime concentrations were higher than night-time for aerosol H +, sulfate, fine mass and ozone. Prolonged episodes of atmospheric acidity, sulfate, and ozone were associated with air masses arriving at the measurement site from the west and from the southwest over Lake Erie. Sulfate concentrations measured at the lakeshore camp were more than twice those measured at inland sites during extreme pollution episodes. The concentration gradient observed with onshore flow was potentially due to enhanced deposition near the lakeshore caused by discontinuities in the meteorological fields in this region.

  13. Automated measurement of fast mitochondrial transport in neurons

    PubMed Central

    Miller, Kyle E.; Liu, Xin-An; Puthanveettil, Sathyanarayanan V.

    2015-01-01

    There is growing recognition that fast mitochondrial transport in neurons is disrupted in multiple neurological diseases and psychiatric disorders. However, a major constraint in identifying novel therapeutics based on mitochondrial transport is that the large-scale analysis of fast transport is time consuming. Here we describe methodologies for the automated analysis of fast mitochondrial transport from data acquired using a robotic microscope. We focused on addressing questions of measurement precision, speed, reliably, workflow ease, statistical processing, and presentation. We used optical flow and particle tracking algorithms, implemented in ImageJ, to measure mitochondrial movement in primary cultured cortical and hippocampal neurons. With it, we are able to generate complete descriptions of movement profiles in an automated fashion of hundreds of thousands of mitochondria with a processing time of approximately one hour. We describe the calibration of the parameters of the tracking algorithms and demonstrate that they are capable of measuring the fast transport of a single mitochondrion. We then show that the methods are capable of reliably measuring the inhibition of fast mitochondria transport induced by the disruption of microtubules with the drug nocodazole in both hippocampal and cortical neurons. This work lays the foundation for future large-scale screens designed to identify compounds that modulate mitochondrial motility. PMID:26578890

  14. The landscape Reynolds number and other dimensionless measures of Earth surface processes

    NASA Astrophysics Data System (ADS)

    Haff, P. K.

    2007-11-01

    An analogy between turbulent fluid systems and landscape drainage systems [Parker, G., Haff, P.K., Murray, A.B., 2001, EOS, Transactions of the American Geophysical Union, 82, pp. F564.] is suggested by the observation that transport in both systems can be approximated by diffusion with size-proportional effective diffusivities, with a cross-over at small scales to Fickian diffusion. The "landscape" Reynolds number of a typical fluvial landscape is estimated to be of order Re L ˜ 10 6 to 10 9, these large values reflecting the relative efficiency of fluvial transport compared to creep. Re L is the ratio of the large-scale effective diffusivity of rivers to the small-scale diffusivity of creep processes on hillslopes. The spatial dependence of the effective diffusivity produces rivers with logarithmic long-profiles, similar to the profiles of many rivers in nature, and analogous to the logarithmic dependence of mean fluid velocity on distance from a wall in turbulent flow. The landscape example suggests how other generalized "Reynolds numbers" can be constructed as ratios of large-scale to small-scale diffusivities to measure the efficiencies of complex processes that affect the surface. As an example, the global airline transportation network is estimated to have an efficacy relative to that of direct human mechanisms for transport of similar goods and materials of about 10 8 as measured by a corresponding "technology" Reynolds number. The appearance of such large dimensionless numbers, pertaining to the consequences of human invention and design, reflects the emergence of the technosphere as an increasingly efficient overlay on the historical domain of biology and surficial geology.

  15. Gasificaton Transport: A Multiphase CFD Approach & Measurements

    SciTech Connect

    Dimitri Gidaspow; Veeraya Jiradilok; Mayank Kashyap; Benjapon Chalermsinsuwan

    2009-02-14

    The objective of this project was to develop predictive theories for the dispersion and mass transfer coefficients and to measure them in the turbulent fluidization regime, using existing facilities. A second objective was to use our multiphase CFD tools to suggest optimized gasifier designs consistent with aims of Future Gen. We have shown that the kinetic theory based CFD codes correctly compute: (1) Dispersion coefficients; and (2) Mass transfer coefficients. Hence, the kinetic theory based CFD codes can be used for fluidized bed reactor design without any such inputs. We have also suggested a new energy efficient method of gasifying coal and producing electricity using a molten carbonate fuel cell. The principal product of this new scheme is carbon dioxide which can be converted into useful products such as marble, as is done very slowly in nature. We believe this scheme is a lot better than the canceled FutureGen, since the carbon dioxide is safely sequestered.

  16. Measurement of non-volatile particle number size distribution

    NASA Astrophysics Data System (ADS)

    Gkatzelis, G. I.; Papanastasiou, D. K.; Florou, K.; Kaltsonoudis, C.; Louvaris, E.; Pandis, S. N.

    2015-06-01

    An experimental methodology was developed to measure the non-volatile particle number concentration using a thermodenuder (TD). The TD was coupled with a high-resolution time-of-flight aerosol mass spectrometer, measuring the chemical composition and mass size distribution of the submicrometer aerosol and a scanning mobility particle sizer (SMPS) that provided the number size distribution of the aerosol in the range from 10 to 500 nm. The method was evaluated with a set of smog chamber experiments and achieved almost complete evaporation (> 98 %) of secondary organic as well as freshly nucleated particles, using a TD temperature of 400 °C and a centerline residence time of 15 s. This experimental approach was applied in a winter field campaign in Athens and provided a direct measurement of number concentration and size distribution for particles emitted from major pollution sources. During periods in which the contribution of biomass burning sources was dominant, more than 80 % of particle number concentration remained after passing through the thermodenuder, suggesting that nearly all biomass burning particles had a non-volatile core. These remaining particles consisted mostly of black carbon (60 % mass contribution) and organic aerosol, OA (40 %). Organics that had not evaporated through the TD were mostly biomass burning OA (BBOA) and oxygenated OA (OOA) as determined from AMS source apportionment analysis. For periods during which traffic contribution was dominant 50-60 % of the particles had a non-volatile core while the rest evaporated at 400 °C. The remaining particle mass consisted mostly of black carbon (BC) with an 80 % contribution, while OA was responsible for another 15-20 %. Organics were mostly hydrocarbon-like OA (HOA) and OOA. These results suggest that even at 400 °C some fraction of the OA does not evaporate from particles emitted from common combustion processes, such as biomass burning and car engines, indicating that a fraction of this type of OA is of extremely low volatility.

  17. Measuring the lensing potential with tomographic galaxy number counts

    NASA Astrophysics Data System (ADS)

    Montanari, Francesco; Durrer, Ruth

    2015-10-01

    We investigate how the lensing potential can be measured tomographically with future galaxy surveys using their number counts. Such a measurement is an independent test of the standard ?CDM framework and can be used to discern modified theories of gravity. We perform a Fisher matrix forecast based on galaxy angular-redshift power spectra, assuming specifications consistent with future photometric Euclid-like surveys and spectroscopic SKA-like surveys. For the Euclid-like survey we derive a fitting formula for the magnification bias. Our analysis suggests that the cross correlation between different redshift bins is very sensitive to the lensing potential such that the survey can measure the amplitude of the lensing potential at the same level of precision as other standard ?CDM cosmological parameters.

  18. Measurements of Molecular Mixing in a High Schmidt Number Rayleigh-Taylor Mixing Layer

    SciTech Connect

    Mueschke, N J; Schilling, O; Youngs, D L; Andrews, M

    2007-12-03

    Molecular mixing measurements are performed for a high Schmidt number (Sc {approx} 10{sup 3}), small Atwood number (A {approx} 7.5 x 10{sup -4}) buoyancy-driven turbulent Rayleigh-Taylor mixing layer in a water channel facility. Salt was added to the top stream to create the desired density difference. The degree of molecular mixing was measured as a function of time by monitoring a diffusion-limited chemical reaction between the two fluid streams. The pH of each stream was modified by the addition of acid or alkali such that a local neutralization reaction occurred as the two fluids molecularly mixed. The progress of this neutralization reaction was tracked by the addition of phenolphthalein - a pH-sensitive chemical indicator - to the acidic stream. Accurately calibrated backlit optical techniques were used to measure the average concentration of the colored chemical indicator. Comparisons of chemical product formation for pre-transitional buoyancy- and shear-driven mixing layers are given. It is also shown that experiments performed at different equivalence ratios (acid/alkali concentration) can be combined to obtain a mathematical relationship between the colored product formed and the density variance. This relationship was used to obtain high-fidelity, quantitative measures of the degree of molecular mixing which are independent of probe resolution constraints. The dependence of such mixing parameters on the Schmidt and Reynolds numbers is examined by comparing the current Sc {approx} 10{sup 3} measurements with Sc = 0.7 gas-phase and Pr = 7 liquid-phase measurements. This comparison indicates that the Schmidt number has a large effect on the bulk quantity of mixed fluid at small Reynolds numbers Re{sub h} < 10{sup 3}. At late times, all mixing parameters indicated a greater degree of molecular mixing and a decreased Schmidt number dependence. Implications for the development and quantitative assessment of turbulent transport and mixing models appropriate for Rayleigh?Taylor instability-induced mixing are discussed.

  19. Estimating the theoretical semivariogram from finite numbers of measurements

    USGS Publications Warehouse

    Zheng, Lingyun; Silliman, S.E.

    2000-01-01

    We investigate from a theoretical basis the impacts of the number, location, and correlation among measurement points on the quality of an estimate of the semivariogram. The unbiased nature of the semivariogram estimator ??/(r) is first established for a general random process Z(x). The variance of ??z(r) is then derived as a function of the sampling parameters (the number of measurements and their locations). In applying this function to the case of estimating the semivariograms of the transmissivity and the hydraulic head field, it is shown that the estimation error depends on the number of the data pairs, the correlation among the data pairs (which, in turn, are determined by the form of the underlying semivariogram ??(r)), the relative locations of the data pairs, and the separation distance at which the semivariogram is to be estimated. Thus design of an optimal sampling program for semivariogram estimation should include consideration of each of these factors. Further, the function derived for the variance of ??z(r) is useful in determining the reliability of a semivariogram developed from a previously established sampling design.

  20. Heat Transport in Low-Rossby-Number Rayleigh-Benard Convection Keith Julien,1

    E-print Network

    Knobloch, Edgar

    Heat Transport in Low-Rossby-Number Rayleigh-Be´nard Convection Keith Julien,1 Edgar Knobloch,2 is the volumetric heat capacity. At large Ra the convective scaling law in a given flow regime assumes the general rotationally constrained Rayleigh-Be´nard convection, that the efficiency of turbulent motion in the fluid bulk

  1. A four-probe thermal transport measurement method for nanostructures

    NASA Astrophysics Data System (ADS)

    Kim, Jaehyun; Ou, Eric; Sellan, Daniel P.; Shi, Li

    2015-04-01

    Several experimental techniques reported in recent years have enabled the measurement of thermal transport properties of nanostructures. However, eliminating the contact thermal resistance error from the measurement results has remained a critical challenge. Here, we report a different four-probe measurement method that can separately obtain both the intrinsic thermal conductance and the contact thermal resistance of individual nanostructures. The measurement device consists of four microfabricated, suspended metal lines that act as resistive heaters and thermometers, across which the nanostructure sample is assembled. The method takes advantage of the variation in the heat flow along the suspended nanostructure and across its contacts to the four suspended heater and thermometer lines, and uses sixteen sets of temperature and heat flow measurements to obtain nine of the thermal resistances in the measurement device and the nanostructure sample, including the intrinsic thermal resistance and the two contact thermal resistances to the middle suspended segment of the nanostructure. Two single crystalline Si nanowires with different cross sections are measured in this work to demonstrate the effectiveness of the method. This four-probe thermal transport measurement method can lead to future discoveries of unique size-dependent thermal transport phenomena in nanostructures and low-dimensional materials, in addition to providing reliable experimental data for calibrating theoretical models.

  2. Measurement of particle transport coefficients on Alcator C-Mod

    SciTech Connect

    Luke, T.C.T.

    1994-10-01

    The goal of this thesis was to study the behavior of the plasma transport during the divertor detachment in order to explain the central electron density rise. The measurement of particle transport coefficients requires sophisticated diagnostic tools. A two color interferometer system was developed and installed on Alcator C-Mod to measure the electron density with high spatial ({approx} 2 cm) and high temporal ({le} 1.0 ms) resolution. The system consists of 10 CO{sub 2} (10.6 {mu}m) and 4 HeNe (.6328 {mu}m) chords that are used to measure the line integrated density to within 0.08 CO{sub 2} degrees or 2.3 {times} 10{sup 16}m{sup {minus}2} theoretically. Using the two color interferometer, a series of gas puffing experiments were conducted. The density was varied above and below the threshold density for detachment at a constant magnetic field and plasma current. Using a gas modulation technique, the particle diffusion, D, and the convective velocity, V, were determined. Profiles were inverted using a SVD inversion and the transport coefficients were extracted with a time regression analysis and a transport simulation analysis. Results from each analysis were in good agreement. Measured profiles of the coefficients increased with the radius and the values were consistent with measurements from other experiments. The values exceeded neoclassical predictions by a factor of 10. The profiles also exhibited an inverse dependence with plasma density. The scaling of both attached and detached plasmas agreed well with this inverse scaling. This result and the lack of change in the energy and impurity transport indicate that there was no change in the underlying transport processes after detachment.

  3. Reynolds Number Effects on a Supersonic Transport at Subsonic High-Lift Conditions (Invited)

    NASA Technical Reports Server (NTRS)

    Owens, L.R.; Wahls, R. A.

    2001-01-01

    A High Speed Civil Transport configuration was tested in the National Transonic Facility at the NASA Langley Research Center as part of NASA's High Speed Research Program. The primary purposes of the tests were to assess Reynolds number scale effects and high Reynolds number aerodynamic characteristics of a realistic, second generation supersonic transport while providing data for the assessment of computational methods. The tests included longitudinal and lateral/directional studies at transonic and low-speed, high-lift conditions across a range of Reynolds numbers from that available in conventional wind tunnels to near flight conditions. Results are presented which focus on Reynolds number and static aeroelastic sensitivities of longitudinal characteristics at Mach 0.30 for a configuration without an empennage. A fundamental change in flow-state occurred between Reynolds numbers of 30 to 40 million, which is characterized by significantly earlier inboard leading-edge separation at the high Reynolds numbers. Force and moment levels change but Reynolds number trends are consistent between the two states.

  4. Flow Visualization of Low Prandtl Number Fluids using Electrochemical Measurements

    NASA Technical Reports Server (NTRS)

    Crunkleton, D.; Anderson, T.; Narayanan, R.; Labrosse, G.

    2003-01-01

    It is well established that residual flows exist in contained liquid metal processes. In 1-g processing, buoyancy forces often drive these flows and their magnitudes can be substantial. It is also known that residual flows can exist during microgravity processing, and although greatly reduced in magnitude, they can influence the properties of the processed materials. Unfortunately, there are very few techniques to visualize flows in opaque, high temperature liquid metals, and those available are not easily adapted to flight investigation. In this study, a novel technique is developed that uses liquid tin as the model fluid and solid-state electrochemical cells constructed from Yttria-Stabilized Zirconia (YSZ) to establish and measure dissolved oxygen boundary conditions. The melt serves as a common electrode for each of the electrochemical cells in this design, while independent reference electrodes are maintained at the outside surfaces of the electrolyte. By constructing isolated electrochemical cells at various locations along the container walls, oxygen is introduced or extracted by imposing a known electrical potential or passing a given current between the melt and the reference electrode. This programmed titration then establishes a known oxygen concentration boundary condition at the selected electrolyte-melt interface. Using the other cells, the concentration of oxygen at the electrolyte-melt interface is also monitored by measuring the open-circuit potentials developed between the melt and reference electrodes. Thus the electrochemical cells serve to both establish boundary conditions for the passive tracer and sense its path. Rayleigh-Benard convection was used to validate the electrochemical approach to flow visualization. Thus, a numerical characterization of the second critical Rayleigh numbers in liquid tin was conducted for a variety of Cartesian aspect ratios. The extremely low Prandtl number of tin represents the lowest value studied numerically. Additionally, flow field oscillations are visualized and the effect of tilt on convecting systems is quantified. Experimental studies of the effect of convection in liquid tin are presented. Three geometries are studied: (1) double electrochemical cell with vertical concentration gradients; (2) double cell with horizontal concentration gradients; and (3) multiple cells with vertical temperature gradients. The first critical Rayleigh number transition is detected with geometry (1) and it is concluded that current measurements are not as affected by convection as EMF measurements. The system is compared with numerical simulations in geometry (2), and oscillating convection is detected with geometry (3).

  5. Measurement of Water Transport from Saturated Pumice Aggregates to Hardening Cement Paste

    E-print Network

    Bentz, Dale P.

    Measurement of Water Transport from Saturated Pumice Aggregates to Hardening Cement Paste by Pietro-ray absorption showed that considerable transport of water from saturated lightweight aggregates (pumice

  6. Temperature and number density measurements using Raman scattering in turbulent-supersonic-combusting flows

    NASA Astrophysics Data System (ADS)

    Jeyashekar, Nigil Satish

    Scramjet engines propelled at hypersonic velocities have the potential to replace existing rocket launchers. Commercializing the vehicle is an arduous task, owing to issues relating to low combustion efficiency. The performance, thrust, and speed of the engine can be improved by optimizing: turbulence-chemistry interaction to provide mixing conditions favorable for the chemistry, pressure buildup, and re-circulation of hydrogen throughout the engine. The performance of the engine can be measured, flow and chemical dynamics can be evaluated when all three variables in the transport equations are known. The variables are instantaneous flow velocity, static temperature (refers to the macroscopic temperature and not the molecular species temperature), and total number density at a point in the flow. The motive is to build a non-intrusive tool to measure thermodynamic quantities (static temperature and total number density). This can be integrated with a velocity measurement tool, in the future, to obtain all three variables simultaneously and instantaneously. The dissertation describes in detail the motivation for the proposed work, with introduction to the formalism involved, with a concise literature review, followed by mathematical perspective to obtain the working equations for temperature and number density. The design of the adiabatic burner and the experimental setup used for calibration is discussed with the uncertainty involved in measurements. The measurements are made for a certain set of flow conditions in the laminar burner by Raman scattering and is validated by comparing it to the theoretical/adiabatic flame temperature and mole fraction plots, in lean and rich regime. This technique is applied to turbulent, supersonic, hydrogen-air flame of an afterburning rocket nozzle. The statistics of temperature and total number density versus the corresponding values at adiabatic conditions gives the departure from thermal and chemical equilibrium. The extent of mixing and combustion can be concluded from such statistics. The future work will involve experimental modifications to make line and planar measurements in combusting jets.

  7. Precision measurements constraints on the number of Higgs doublets

    E-print Network

    A. E. Cárcamo Hernández; Sergey Kovalenko; Iván Schmidt

    2015-05-19

    We consider an extension of the Standard Model with an arbitrary number $N$ of Higgs doublets (NHDM), and calculate their contribution to the oblique parameters $S$ and $T$. We examine the possible limitations on $N$ from precision measurements of these parameters. In view of the complexity of the general case of NHDM, we analyze several benchmark scenarios for the Higgs mass spectrum, identifying the lightest CP-even Higgs with the Higgs-like particle recently observed at the LHC with the mass of $\\sim 125$ GeV. The rest of the Higgses are put above the mass scale of $\\sim 600$ GeV, below which the LHC experiments do not detect any Higgs-like signals except for the former famous one. We show that, in a scenario, with all the heavy Higgses degenerate at any scale, there are no limitations on the number $N$ of the Higgs doublets. However, upper limits appear for certain not completely degenerate configurations of the heavy Higgses.

  8. A rain splash transport equation assimilating field and laboratory measurements

    USGS Publications Warehouse

    Dunne, T.; Malmon, D.V.; Mudd, S.M.

    2010-01-01

    Process-based models of hillslope evolution require transport equations relating sediment flux to its major controls. An equation for rain splash transport in the absence of overland flow was constructed by modifying an approach developed by Reeve (1982) and parameterizing it with measurements from single-drop laboratory experiments and simulated rainfall on a grassland in East Africa. The equation relates rain splash to hillslope gradient, the median raindrop diameter of a storm, and ground cover density; the effect of soil texture on detachability can be incorporated from other published results. The spatial and temporal applicability of such an equation for rain splash transport in the absence of overland flow on uncultivated hillslopes can be estimated from hydrological calculations. The predicted transport is lower than landscape-averaged geologic erosion rates from Kenya but is large enough to modify short, slowly eroding natural hillslopes as well as microtopographic interrill surfaces between which overland flow transports the mobilized sediment. Copyright 2010 by the American Geophysical Union. Copyright 2010 by the American Geophysical Union.

  9. Optical measurement of osmotic water transport in cultured cells. Role of glucose transporters

    PubMed Central

    1992-01-01

    Methodology was developed to measure osmotic water permeability in monolayer cultured cells and applied to examine the proposed role of glucose transporters in the water pathway (1989. Proc. Natl. Acad. Sci. USA. 86:8397-8401). J774 macrophages were grown on glass coverslips and mounted in a channel-type perfusion chamber for rapid fluid exchange without cell detachment. Relative cell volume was measured by 45 degrees light scattering using an inverted microscope; measurement accuracy was validated by confocal imaging microscopy. The time required for greater than 90% fluid exchange was less than 1 s. In response to a decrease in perfusate osmolality from 300 to 210 mosM, cells swelled without lag at an initial rate of 4.5%/s, corresponding to a water permeability coefficient of (6.3 +/- 0.4) x 10(-3) cm/s (SE, n = 20, 23 degrees C), assuming a cell surface-to-volume ratio of 4,400 cm-1. The initial rate of cell swelling was proportional to osmotic gradient size, independent of perfusate viscosity, and increased by amphotericin B (25 micrograms/ml), and had an activation energy of 10.0 +/- 1 kcal/mol (12-39 degrees C). The compounds phloretin (20 microM) and cytochalasin B (2.5 micrograms/ml) inhibited glucose transport by greater than 85% but did not influence Pf in paired experiments in which Pf was measured before and after inhibitor addition. The mercurials HgCl2 (0.1 mM) and p-chloromercuribenzoate (1 mM) did not inhibit Pf. A stopped-flow light scattering technique was used to measure Pf independently in J774 macrophages grown in suspension culture. Pf in suspended cells was (4.4 +/- 0.3) x 10(-3) cm/s (assuming a surface-to-volume ratio of 8,800 cm-1), increased more than threefold by amphotericin B, and not inhibited by phloretin and cytochalasin B under conditions of strong inhibition of glucose transport. The glucose reflection coefficient was 0.98 +/- 0.03 as measured by induced osmosis, assuming a unity reflection coefficient for sucrose. These results establish a quantitative method for measurement of osmotic water transport in adherent cultured cells and provide evidence that glucose transporters are not involved in the water transporting pathway. PMID:1597679

  10. Black Carbon Particle Number Distribution Measurements during the ATHENS-2013 Winter Campaign

    NASA Astrophysics Data System (ADS)

    Gkatzelis, Georgios; Papanastasiou, Dimitris; Florou, Kalliopi; Kaltsonoudis, Christos; Louvaris, Eyaggelos; Bezentakos, Spiridon; Biskos, Georgios; Pandis, Spuros

    2014-05-01

    Black Carbon (BC) particles emitted by anthropogenic sources play an important role both in climate change and in air quality degradation. Open burning in forests and savannas, combustion of diesel and solid fuels for cooking and heating in homes represent the majority of BC emissions. Earlier work has focused on the BC atmospheric direct radiative forcing that is mostly related to its mass concentration and optical properties of the corresponding particles. A variety of measurement techniques are used to measure the mass concentration of BC by taking advantage of its optical or physical properties. Moreover, the carbonaceous particles containing BC are also important for the indirect forcing of climate. This effect is mostly related to the number concentration of BC particles. The number distribution of BC particles especially below 100 nm is quite uncertain due to limitations of the existing measurement techniques. In this work we employed a thermodenuder-based method as an approach for the measurement of the BC number distribution. More specifically, we combined a thermodenuder (TD) operating at temperatures up to 300 ° C, with a Scanning Mobility Particle Sizer (SMPS) and a High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF AMS). Aerosol size and composition measurements were carried out both at ambient and at elevated TD temperatures in Athens field campaign during January and February of 2013. In parallel, a Multi-Angle Absorption Photometer (MAAP) provided information about the BC mass concentration while a Hygroscopic Tandem Differential Mobility Analyzer (HTDMA) measured the mixing state and the hygroscopicity of the particles as a function of their size. These measurements were then combined to estimate the number concentration of BC particles. Our analysis focused on different periods during the study. During some of them one source dominated the carbonaceous aerosol concentration. Such periods included rush hour traffic, nighttime wood burning, clean air transported from other areas, mixed sources, etc. The number fraction remaining after heating at 300 ° C for approximately 15 s during wood burning events was 80-90%, suggesting that practically all particles contained nonvolatile material. Combining the SMPS, MAAP, AMS, and HTDMA measurements we show that most of the sampled material was BC. On the contrary, during rush hour traffic the number fraction remaining was only 50-60% suggesting that more than half of the particles did not contain BC.

  11. The variable number of tandem repeats element in DAT1 regulates in vitro dopamine transporter density

    PubMed Central

    VanNess, Sidney H; Owens, Michael J; Kilts, Clinton D

    2005-01-01

    Background A 40-bp variable number of tandem repeats (VNTR) polymorphism exists in the 15th exon of DAT1, the gene encoding the human dopamine transporter (DAT). Though the VNTR resides in a region encoding the 3' untranslated region (UTR) and does not alter the protein's amino acid sequence, the prevalent 10-repeat variant has shown both linkage and association to Attention Deficit Hyperactivity Disorder (ADHD). In this study, we examined the effects of the DAT1 VNTR on measures of in vitro DAT expression and pharmacology. A series of four DAT1 constructs, each containing the DAT1 coding region, but varying with respect to the downstream presence or content of the 3'UTR, were engineered and stably transfected into an HEK-293 variant using Flp-In integration, an enzyme-mediated, site-specific recombination technology. Results [3H] Win 35,428 saturation binding assays and DAT immunoblots revealed statistically significant differences in DAT expression attributable to DAT1 genotype. Cells harboring the 10-repeat DAT1 variant were characterized by a Bmax approximately 50% greater than cells with the 9-repeat VNTR; those containing only the DAT1 coding region or the coding region flanked by a truncated 3' UTR resulted in greater DAT density than either of the naturalistic 9- and 10-repeat variants. Competition binding assays showed no statistically significant DAT1 genotype effects on the DAT affinity for methylphenidate, a finding consistent with the positional location of the VNTR. Conclusion This study identified the DAT1 VNTR as a functional polymorphism and provides an interpretive framework for its association with behavioral phenotypes. PMID:16309561

  12. Investigation of Transonic Reynolds Number Scaling on a Twin-Engine Transport

    NASA Technical Reports Server (NTRS)

    Curtin, M. M.; Bogue, D. R.; Om, D.; Rivers, S. M. B.; Pendergraft, O. C., Jr.; Wahls, R. A.

    2002-01-01

    This paper discusses Reynolds number scaling for aerodynamic parameters including force and wing pressure measurements. A full-span model of the Boeing 777 configuration was tested at transonic conditions in the National Transonic Facility (NTF) at Reynolds numbers (based on mean aerodynamic chord) from 3.0 to 40.0 million. Data was obtained for a tail-off configuration both with and without wing vortex generators and flap support fairings. The effects of aeroelastics were separated from Reynolds number effects by varying total pressure and temperature independently. Data from the NTF at flight Reynolds number are compared with flight data to establish the wind tunnel/flight correlation. The importance of high Reynolds number testing and the need for developing a process for transonic Reynolds number scaling is discussed. This paper also identifies issues that need to be worked for Boeing Commercial to continue to conduct future high Reynolds number testing in the NTF.

  13. THE POSSIBILITIES OF TRANSPORTATION CONCURRENCY PROPOSAL AND EVALUATION OF MEASUREMENT ALTERNATIVES

    E-print Network

    , ride sharing programs, demand management, and other transportation systems management strategies." #12 endorsed by them. TRANSPORTATION CONCURRENCY Washington State's Growth Management Act (GMA) requires jurisdictions to adopt ordinances that establish a concurrency measurement system for transportation

  14. Sustainability Enhancement Tool for State Departments of Transportation Using Performance Measurement

    E-print Network

    Quadrifoglio, Luca

    Sustainability Enhancement Tool for State Departments of Transportation Using Performance for transportation agencies, such as state departments of transportation, to evaluate and enhance sustainability. This research proposes a performance measurement­based framework and evaluation methodology for sustainable

  15. Review on measurement techniques of transport properties of nanowires.

    PubMed

    Rojo, Miguel Muñoz; Calero, Olga Caballero; Lopeandia, A F; Rodriguez-Viejo, J; Martín-Gonzalez, Marisol

    2013-12-01

    Physical properties at the nanoscale are novel and different from those in bulk materials. Over the last few decades, there has been an ever growing interest in the fabrication of nanowire structures for a wide variety of applications including energy generation purposes. Nevertheless, the study of their transport properties, such as thermal conductivity, electrical conductivity or Seebeck coefficient, remains an experimental challenge. For instance, in the particular case of nanostructured thermoelectrics, theoretical calculations have shown that nanowires offer a promising way of enhancing the hitherto low efficiency of these materials in the conversion of temperature differences into electricity. Therefore, within the thermoelectrical community there has been a great experimental effort in the measurement of these quantities in actual nanowires. The measurements of these properties at the nanoscale are also of interest in fields other than energy, such as electrical components for microchips, field effect transistors, sensors, and other low scale devices. For all these applications, knowing the transport properties is mandatory. This review deals with the latest techniques developed to perform the measurement of these transport properties in nanowires. A thorough overview of the most important and modern techniques used for the characterization of different kinds of nanowires will be shown. PMID:24113712

  16. Reynolds Number Effects on the Stability and Control Characteristics of a Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Owens, L. R.; Wahls, R. A.; Elzey, M. B.; Hamner, M. P.

    2002-01-01

    A High Speed Civil Transport (HSCT) configuration was tested in the National Transonic Facility at the NASA Langley Research Center as part of NASA's High Speed Research Program. A series of tests included longitudinal and lateral/directional studies at transonic and low speed, high-lift conditions across a range of Reynolds numbers from that available in conventional wind tunnels to near flight conditions. Results presented focus on Reynolds number sensitivities of the stability and control characteristics at Mach 0.30 and 0.95 for a complete HSCT aircraft configuration including empennage. The angle of attack where the pitching-moment departure occurred increased with higher Reynolds numbers for both the landing and transonic configurations. The stabilizer effectiveness increased with Reynolds number for both configurations. The directional stability also increased with Reynolds number for both configurations. The landing configuration without forebody chines exhibited a large yawing-moment departure at high angles of attack and zero sideslip that varied with increasing Reynolds numbers. This departure characteristic nearly disappeared when forebody chines were added. The landing configuration's rudder effectiveness also exhibited sensitivities to changes in Reynolds number.

  17. Strongly Intensive Measures for Particle Number Fluctuations: Effects of Hadronic Resonances

    E-print Network

    Viktor V. Begun; Mark I. Gorenstein; Katarzyna Grebieszkow

    2015-05-15

    Strongly intensive measures $\\Delta$ and $\\Sigma$ are used to study event-by-event fluctuations of hadron multiplicities in nucleus-nucleus collisions. The effects of resonance decays are investigated within statistical model and relativistic transport model. Two specific examples are considered: resonance decays to two positively charged particles (e.g., $\\Delta^{++}\\rightarrow p+ \\pi^+$) and to $\\pi^+\\pi^-$-pairs. (e.g., $\\rho^0\\rightarrow \\pi^-+\\pi^+$). It is shown that resonance abundances at the chemical freeze-out can be estimated by measuring the fluctuations of the number of stable hadrons. These model results are compared to the full hadron-resonance gas analysis within both the grand canonical and canonical ensemble. The ultra-relativistic quantum molecular dynamics (UrQMD) model of nucleus-nucleus collisions is used to illustrate the role of global charge conservation, centrality selection, and limited experimental acceptance.

  18. Strongly intensive measures for particle number fluctuations: effects of hadronic resonances

    NASA Astrophysics Data System (ADS)

    Begun, Viktor V.; Gorenstein, Mark I.; Grebieszkow, Katarzyna

    2015-07-01

    The strongly intensive measures ? and ? are used to study event-by-event fluctuations of hadron multiplicities in nucleus-nucleus collisions. The effects of resonance decays are investigated using a statistical model and a relativistic transport model. Two specific examples are considered: resonance decays to two positively charged particles (e.g., {{? }++}\\to p+{{? }+}) and to {{? }+}{{? }-} pairs (e.g., {{? }0}\\to {{? }-}+{{? }+}). It is shown that resonance abundances at the chemical freeze-out can be estimated by measuring the fluctuations of the number of stable hadrons. These model results are compared against a full hadronresonance gas analysis within both the grand canonical and canonical ensembles. The ultra-relativistic quantum molecular dynamics (UrQMD) model of nucleus-nucleus collisions is used to illustrate the role of global charge conservation, centrality selection, and limited experimental acceptance.

  19. Rapid Measurement of Neutron Dose Rate for Transport Index

    SciTech Connect

    Morris, R.L.

    2000-02-27

    A newly available neutron dose equivalent remmeter with improved sensitivity and energy response has been put into service at Rocky Flats Environmental Technology Site (RFETS). This instrument is being used to expedite measurement of the Transport Index and as an ALARA tool to identify locations where slightly elevated neutron dose equivalent rates exist. The meter is capable of measuring dose rates as low as 0.2 {mu}Sv per hour (20 {mu}rem per hour). Tests of the angular response and energy response of the instrument are reported. Calculations of the theoretical instrument response made using MCNP{trademark} are reported for materials typical of those being shipped.

  20. Characterization of Lorenz number with Seebeck coefficient measurement

    SciTech Connect

    Kim, Hyun-Sik; Gibbs, Zachary M.; Tang, Yinglu; Wang, Heng; Snyder, G. Jeffrey

    2015-04-01

    In analyzing zT improvements due to lattice thermal conductivity (?{sub L}) reduction, electrical conductivity (?) and total thermal conductivity (?{sub Total}) are often used to estimate the electronic component of the thermal conductivity (?{sub E}) and in turn ?{sub L} from ?{sub L} = ? ?{sub Total} ? L?T. The Wiedemann-Franz law, ?{sub E} = L?T, where L is Lorenz number, is widely used to estimate ?{sub E} from ? measurements. It is a common practice to treat L as a universal factor with 2.44 × 10{sup ?8} W?K{sup ?2} (degenerate limit). However, significant deviations from the degenerate limit (approximately 40% or more for Kane bands) are known to occur for non-degenerate semiconductors where L converges to 1.5 × 10{sup ?8} W?K{sup ?2} for acoustic phonon scattering. The decrease in L is correlated with an increase in thermopower (absolute value of Seebeck coefficient (S)). Thus, a first order correction to the degenerate limit of L can be based on the measured thermopower, |S|, independent of temperature or doping. We propose the equation: L=1.5+exp[?(|S|)/(116) ] (where L is in 10{sup ?8} W?K{sup ?2} and S in ?V/K) as a satisfactory approximation for L. This equation is accurate within 5% for single parabolic band/acoustic phonon scattering assumption and within 20% for PbSe, PbS, PbTe, Si{sub 0.8}Ge{sub 0.2} where more complexity is introduced, such as non-parabolic Kane bands, multiple bands, and/or alternate scattering mechanisms. The use of this equation for L rather than a constant value (when detailed band structure and scattering mechanism is not known) will significantly improve the estimation of lattice thermal conductivity.

  1. Characterization of Lorenz number with Seebeck coefficient measurement

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Sik; Gibbs, Zachary M.; Tang, Yinglu; Wang, Heng; Snyder, G. Jeffrey

    2015-04-01

    In analyzing zT improvements due to lattice thermal conductivity (?L) reduction, electrical conductivity (?) and total thermal conductivity (?Total) are often used to estimate the electronic component of the thermal conductivity (?E) and in turn ?L from ?L = ˜ ?Total - L?T. The Wiedemann-Franz law, ?E = L?T, where L is Lorenz number, is widely used to estimate ?E from ? measurements. It is a common practice to treat L as a universal factor with 2.44 × 10-8 W?K-2 (degenerate limit). However, significant deviations from the degenerate limit (approximately 40% or more for Kane bands) are known to occur for non-degenerate semiconductors where L converges to 1.5 × 10-8 W?K-2 for acoustic phonon scattering. The decrease in L is correlated with an increase in thermopower (absolute value of Seebeck coefficient (S)). Thus, a first order correction to the degenerate limit of L can be based on the measured thermopower, |S|, independent of temperature or doping. We propose the equation: L = 1 . 5 + exp [" separators=" - /| S | 116 ] (where L is in 10-8 W?K-2 and S in ?V/K) as a satisfactory approximation for L. This equation is accurate within 5% for single parabolic band/acoustic phonon scattering assumption and within 20% for PbSe, PbS, PbTe, Si0.8Ge0.2 where more complexity is introduced, such as non-parabolic Kane bands, multiple bands, and/or alternate scattering mechanisms. The use of this equation for L rather than a constant value (when detailed band structure and scattering mechanism is not known) will significantly improve the estimation of lattice thermal conductivity.

  2. Children's Number-Line Estimation Shows Development of Measurement Skills (Not Number Representations)

    ERIC Educational Resources Information Center

    Cohen, Dale J.; Sarnecka, Barbara W.

    2014-01-01

    Children's understanding of numbers is often assessed using a number-line task, where the child is shown a line labeled with 0 at one end and a higher number (e.g., 100) at the other end. The child is then asked where on the line some intermediate number (e.g., 70) should go. Performance on this task changes predictably during childhood, and…

  3. Measurement of charge transport through organic semiconducting devices

    NASA Astrophysics Data System (ADS)

    Klenkler, Richard A.

    2007-12-01

    In this thesis, two important and unexplored areas of organic semiconductor device physics are investigated: The first area involves determining the effect of energy barriers and intermixing at the interfaces between hole transport layers (HTLs). This effect was discerned by first establishing a method of pressure-laminating successive solution coated HTLs to gether. It was found that in the range of 0.8--3.0 MPa a pressure-laminated interface between two identical HTLs causes no measurable perturbation to charge transport. By this method, 2 different HTLs can be sandwiched together to create a discrete interface, and by inserting a mixed HTL in the middle an intermixed interface between the 2 HTLs can be simulated. With these sandwiched devices, charge injection across discrete versus intermixed interfaces were compared using time-of-flight measurements. For the hole transport materials investigated, no perturbation to the overall charge transport was observed with the discrete interface, however in contrast the rate of charge transport was clearly reduced through the intermixed interface. The second area that was investigated pertains to the development of a bulk mobility measurement technique that has a higher resolution than existing methods. The approach that was used involved decoupling the charge carrier transient signal from the device charging circuit. With this approach, the RC time constant constraint that limits the resolution of existing methods is eliminated. The resulting method, termed the photoinduced electroluminescence (EL) mobility measurement technique, was then used to compare the electron mobility of the metal chelate, AlQ3 to that of the novel triazine material, BTB. Results showed that BTB demonstrated an order of magnitude higher mobility than AlQ3. Overall, these findings have broad implications regarding device design. The pressure-lamination method could be used, e.g., as a diagnostic tool to help in the design of multilayer xerographic photoreceptors, such as those that include an abrasion resistant overcoat. Further, the photoinduced EL technique could be use as a tool to help characterize charge flow and balance in organic light emitting devices amongst others.

  4. Comparison of sources of submicron particle number concentrations measured at two sites in Rochester, NY.

    PubMed

    Kasumba, John; Hopke, Philip K; Chalupa, David C; Utell, Mark J

    2009-09-01

    Sources contributing to the submicron particles (100-470 nm) measured between January 2002 and December 2007 at two different New York State Department of Environmental Conservation (NYS DEC) sites in Rochester, NY were identified and apportioned using a bilinear receptor model, positive matrix factorization (PMF). Measurements of aerosol size distributions and number concentrations for particles in the size range of 10-500 nm have been made since December 2001 to date in Rochester. The measurements are being made using a scanning mobility particle sizer (SMPS) consisting of a DMA and a CPC (TSI models 3071 and 3010, respectively). From December 2001 to March 2004, particle measurements were made at the NYS DEC site in downtown Rochester, but it was moved to the eastside of Rochester in May 2004. Each measurement period was divided into three seasons i.e., winter (December, January, and February), summer (June, July, and August), and the transitional periods (March, April, May, September, October, and November) so as to avoid experimental uncertainty resulting from too large season-to-season variability in ambient temperature and solar photon intensity that would lead to unstable/non-stationary size distributions. Therefore, the seasons were analyzed independently for possible sources. Ten sources were identified at both sites and these include traffic, nucleation, residential/commercial heating, industrial emissions, secondary nitrate, ozone- rich secondary aerosol, secondary sulfate, regionally transported aerosol, and a mixed source of nucleation and traffic. These results show that the measured total outdoor particle number concentrations in Rochester generally vary with similar temporal patterns, suggesting that the central monitoring site data can be used to estimate outdoor exposure in other parts of the city. PMID:19541346

  5. Axial turbulent stress transport in high and low Reynolds number boundary layers

    NASA Astrophysics Data System (ADS)

    Klewicki, J.; Priyadarshana, P.; Sadr, R.; Metzger, M.

    2000-11-01

    A six wire hot-wire probe consisting of a vertical array of three closely spaced x-arrays was used to acquire time resolved measurements of terms in the transport equation for the axial stress, baru^2 . Measurements were acquired in zero pressure gradient boundary layers at R_? \\cong 2 × 10^3 and R_? \\cong 5 × 10^6 . The low R_? experiments were conducted in a 17.1m wind tunnel at the Unversity of Utah. The high R_? experiments were conducted at the SLTEST facility in Utah's west desert. Because of the large scales and low speeds of both the high and low R_? flows, the measurements were well resolved in both space and time. Comparisons were made for measurements in the logarithmic layer. Of particular interest is the wall-normal turbulent transport term, fracpartial(u^2v)partial y . The results are interpreted in terms of R_? dependencies, and, in particular, the widening disparity between the large and small scales with increasing R_? .

  6. Experimental studies of Reynolds number dependence of turbulent mixing and transport

    NASA Astrophysics Data System (ADS)

    Warhaft, Z.

    Predicting turbulent mixing and transport remains a critical problem in industrial flows (combustion chambers, mixers, ventilation systems, etc.) and in the environment (smoke plumes, etc.). The mixing and transport processes are often a strong function of Reynolds number (Re) and yet there is a paucity of information on their Re dependence. We propose experiments of passive scalar mixing in isotropic grid turbulence whereby the Taylor Reynolds number (R(sub lambda)) will be varied from 30 to over 400 (60 less than R(sub l) less than 10,000). We will achieve the high R(sub lambda) by means of an active grid, which consists of grid bars with small wings that rotate and flap in a random way. We propose to study basic statistics (pdf, spectra, etc). of a homogeneous passive scalar (linear mean profile), as well as of an inhomogeneous scalar (passive line source) as a function of Re. There are many problems concerning the nature of the fine scale structure of a scalar (e.g., the existence of derivative skewness, the relation of the scalar spectrum to the velocity spectrum, and the rate of spreading of a contaminant plume), placing the similarity theory developed over the past 40 years in doubt, yet there is no information concerning its Reynolds number dependence in isotropic turbulence. The passive scalar will be temperature, although some experiments will be done using helium (which has a Schmidt number of 0.23). Particular emphasis will be placed on higher order statistics of both the signal and its derivative. Our experiments will be related to theory and modeling and to recent advances in direct numerical simulations. We will also do further work on mixing in a jet (also as a function of Re) and will relate this work to the (shearless) grid turbulence.

  7. Field measurements of tracer gas transport by barometric pumping

    SciTech Connect

    Lagus, P.L.; McKinnis, W.B.; Hearst, J.R.; Burkhard, N.R.; Smith, C.F.

    1994-07-28

    Vertical gas motions induced by barometric pressure variations can carry radioactive gases out of the rubblized region produced by an underground nuclear explosion, through overburden rock, into the atmosphere. To better quantify transit time and amount of transport, field experiments were conducted at two sites on Pahute Mesa, Kapelli and Tierra, where radioactive gases had been earlier detected in surface cracks. At each site, two tracer gases were injected into the rubblized chimney 300-400 m beneath the surface and their arrival was monitored by concentration measurements in gas samples extracted from shallow collection holes. The first ``active`` tracer was driven by a large quantity of injected air; the second ``passive`` tracer was introduced with minimal gas drive to observe the natural transport by barometric pumping. Kapelli was injected in the fall of 1990, followed by Tierra in the fall of 1991. Data was collected at both sites through the summer of 1993. At both sites, no surface arrival of tracer was observed during the active phase of the experiment despite the injection of several million cubic feet of air, suggesting that cavity pressurization is likely to induce horizontal transport along high permeability layers rather than vertical transport to the surface. In contrast, the vertical pressure gradients associated with barometric pumping brought both tracers to the surface in comparable concentrations within three months at Kapelli, whereas 15 months elapsed before surface arrival at Tierra. At Kapelli, a quasisteady pumping regime was established, with tracer concentrations in effluent gases 1000 times smaller than concentrations thought to exist in the chimney. Tracer concentrations observed at Tierra were typically an order of magnitude smaller. Comparisons with theoretical calculations suggest that the gases are traveling through {approximately}1 millimeter vertical fractures spaced 2 to 4 meters apart. 6 refs., 18 figs., 3 tabs.

  8. Nature's Microfluidic Transporter: Rotational Cytoplasmic Streaming at High Peclet Numbers Jan-Willem van de Meent,1

    E-print Network

    Goldstein, Raymond E.

    Nature's Microfluidic Transporter: Rotational Cytoplasmic Streaming at High Pe´clet Numbers Jan; published 20 October 2008) Cytoplasmic streaming circulates the contents of large eukaryotic cells, often transport and mixing. Motivated by ``rotational streaming'' in Characean algae, we solve the advection

  9. Skin Friction and Transition Location Measurement on Supersonic Transport Models

    NASA Technical Reports Server (NTRS)

    Kennelly, Robert A., Jr.; Goodsell, Aga M.; Olsen, Lawrence E. (Technical Monitor)

    2000-01-01

    Flow visualization techniques were used to obtain both qualitative and quantitative skin friction and transition location data in wind tunnel tests performed on two supersonic transport models at Mach 2.40. Oil-film interferometry was useful for verifying boundary layer transition, but careful monitoring of model surface temperatures and systematic examination of the effects of tunnel start-up and shutdown transients will be required to achieve high levels of accuracy for skin friction measurements. A more common technique, use of a subliming solid to reveal transition location, was employed to correct drag measurements to a standard condition of all-turbulent flow on the wing. These corrected data were then analyzed to determine the additional correction required to account for the effect of the boundary layer trip devices.

  10. Transport measurements on carbon nanotubes structurally characterized by electron diffraction

    NASA Astrophysics Data System (ADS)

    Allen, C. S.; Elkin, M. D.; Burnell, G.; Hickey, B. J.; Zhang, C.; Hofmann, S.; Robertson, J.

    2011-09-01

    A technique for the structural and electronic characterization of the same individual single wall carbon nanotube is presented. Electron diffraction was performed on carbon nanotubes grown across a perforated silicon nitride film and the chiral indices of individual tubes were determined. By means of a scanning-probe-based nanomanipulator a selected tube was then placed in the desired location across prepatterned electrodes. After patterning further electrodes on-top of the tube electronic transport measurements showed room temperature conductances of up to 0.2 G0. The application of a gate voltage allowed the tuning of the room temperature conductance of the device and measurements at liquid helium temperatures showed signatures of a Coulomb blockade, indicating the formation of a carbon nanotube quantum dot.

  11. Direct measurements of transport properties are essential for site characterization

    SciTech Connect

    Wright, J.; Conca, J.L.

    1994-08-01

    Direct measurements of transport parameters on subsurface sediments using, the UFA method provided detailed hydrostratigraphic mapping, and subsurface flux distributions at a mixed-waste disposal site at Hanford. Seven hundred unsaturated conductivity measurements on fifty samples were obtained in only six months total of UFA run time. These data are used to provide realistic information to conceptual models, predictive models and restoration strategies. The UFA instrument consists of an ultracentrifuge with a constant, ultralow flow pump that provides fluid to the sample surface through a rotating seal assembly and microdispersal system. Effluent from the sample is collected in a transparent, volumetrically-calibrated chamber at the bottom of the sample assembly. Using a strobe light, an observer can check the chamber while the sample is being centrifuged. Materials can be run in the UFA as recomposited samples or in situ samples can be subcored directly into the sample UFA chamber.

  12. Fluorescence measurement of chloride transport in monolayer cultured cells. Mechanisms of chloride transport in fibroblasts.

    PubMed Central

    Chao, A C; Dix, J A; Sellers, M C; Verkman, A S

    1989-01-01

    The methodology has been developed to measure Cl activity and transport in cultured cells grown on a monolayer using the entrapped Cl-sensitive fluorophore 6-methoxy-N-[3-sulfopropyl] quinolinium (SPQ). The method was applied to a renal epithelial cell line, LLC-PKI, and a nonepithelial cell line, Swiss 3T3 fibroblasts. SPQ was nontoxic to cells when present for greater than h in the culture media. To load with SPQ (5 mM), cells were made transiently permeable by exposure to hypotonic buffer (150 mOsm, 4 min). Intracellular fluorescence was monitored continuously by epifluorescence microscopy using low illumination intensity at 360 +/- 5 nm excitation wavelength and photomultiplier detection at greater than 410 nm. Over 60 min at 37 degrees C, there was no photobleaching and less than 10% leakage of SPQ out of cells; intracellular SPQ fluorescence was uniform. SPQ fluorescence was calibrated against intracellular [Cl] using high K solutions containing the ionophores nigericin and tributyltin. The Stern-Volmer constant (Kq) for quenching of intracellular SPQ by Cl was 13 M-1 for fibroblasts and LLC-PKl cells. In the absence of Cl, SPQ lifetime was 26 ns in aqueous solution and 3.7 +/- 0.6 ns in cells, showing that the lower Kq in cells than in free solution (Kq = 118 M-1) was due to SPQ quenching by intracellular anions. To examine Cl transport mechanisms, the time course of intracellular [Cl] was measured in response to rapid Cl addition and removal in the presence of ion or pH gradients. In fibroblasts, three distinct Cl transporting systems were identified: a stilbeneinhibitable Cl/HCO3 exchanger, a furosemide-sensitive Na/K/2Cl cotransporter, and a Ca-regulated Cl conductance. These results establish a direct optical method to measure intracellular [Cl] continuously in cultured cells. Images FIGURE 2 PMID:2482083

  13. Numerical upper bounds on convective heat transport in a layer of fluid of finite Prandtl number: Confirmation of Howard's analytical asymptotic single-wave-number bound

    NASA Astrophysics Data System (ADS)

    Vitanov, Nikolay K.

    2005-10-01

    By means of the Howard-Busse method of the optimum theory of turbulence we investigate numerically the upper bounds on the Nusselt number in a heated-from-below horizontal layer of fluid of finite Prandtl number for the case of rigid boundaries. The bounds are obtained by the solutions of the Euler-Lagrange equations of a variational problem possessing up to three wave numbers. The obtained results are compared to the numerical results for the case of fluid layer with stress-free boundaries [N. K. Vitanov and F. H. Busse, "Upper bounds on heat transport in a horizontal fluid layer with stress-free boundaries," ZAMP 48, 310 (1997)] as well as to the numerical and analytical asymptotic results obtained by Howard ["Heat transport by turbulent convection," J. Fluid Mech. 17, 405 (1963)], Busse ["On Howard's upper bound for heat transport by turbulent convection," J. Fluid Mech. 37, 457 (1969)], and Strauss ["On the upper bounding approach to thermal convection at moderate Rayleigh numbers, II. Rigid boundaries," Dyn. Atm. Oceans 1, 77 (1976)]. We show that for low and intermediate Rayleigh numbers the numerical bounds are positioned below the analytical asymptotic bounds obtained by Howard and Busse. For large Rayleigh numbers the numerical bounds tend to approach the analytical asymptotic bounds. We confirm numerically the bound obtained by Howard for the case of one-wave-number solution of the Euler-Lagrange equations. As the region of validity of the results of the analytical asymptotic theory for solutions of the Euler-Lagrange equations with two and three wave numbers lies in the area of very high Rayleigh numbers the values of the second and third wave numbers are different from their analytical asymptotic values for the values of the Rayleigh number reached by the numerical computation.

  14. Integrating field measurements with flume experiments for analysing fluvial bedload transport in steep mountain streams

    NASA Astrophysics Data System (ADS)

    Beylich, A. A.; Laute, K.; Liermann, S.

    2012-04-01

    Fluvial bedload transport has high importance within sediment budgets of steep catchments and steep mountain streams. It is also of crucial importance as headwater catchments and steep mountain streams can be relevant sediment sources for lowland river systems. Measured under comparable conditions of discharge, rates of fluvial bedload transport can differ by up to one order of magnitude, which is due to the irregular nature of sediment movement. Bedload transport at a defined site depends on factors such as local flow conditions, bed material composition and amount of sediment supply from upstream sources. Irregular deviations from mean rates of bedload transport can be caused by sporadic inputs of material from hillslopes. Permafrost degradation and shifts in ground frost regimes as caused by climate change can lead to increased frequencies and intensities of mass movements on slopes including the increased frequency of rock fall events. By the destabilisation of slope systems higher amounts of sediment are available from a larger number of activated sediment sources. At the same time, a higher frequency of extreme rainfall events and thermally determined runoff-peaks from glacier-fed systems is leading to an increased number of peak runoff events showing a high transport competence with significant fluvial bedload transport. A better general understanding of the exact mechanisms and the dynamics of fluvial bedload transport is essential for the further improvement of river engineering management and hazard mitigation projects. Since 2004, extended and interdisciplinary field investigations on fluvial bedload transport using a novel combination of methods and techniques have been performed in a number of selected stream segments in supply-limited fluvial systems in the inner Nordfjord (Erdalen and Bødalen drainage basins) in western Norway. Field studies include (i) continuous channel discharge monitoring, (ii) frequently repeated surveys of channel morphometry and granulometric analyses, (iii) different tracer techniques (painted stones, magnetic tracers), (iv) Helley-Smith and other basket measurements, (v) horizontally installed impact sensors, (vi) underwater video filming, and (vii) extended biofilm analyses, including also controlled biofilm growing experiments with fixed baskets in selected channels. In addition, field studies with horizontally installed impact sensors were also carried out in selected transport-limited fluvial systems in the Coast Mountains of British Columbia (Canada) in 2010 and 2011. The extended field studies are integrated with advanced flume experiments which were carried out in 2010 and 2011 at the Department of Geography at the University of British Columbia (UBC), Canada for calibration of field measurements. As a key achievement, the entire range of different bedload component grain sizes can be covered by the applied combination of techniques, and the presented integration of interdisciplinary field measurements with flume experiments appears to be a useful approach to study mechanisms, controlling factors and rates of fluvial bedload transport in steep mountain streams.

  15. Measurements of air pollution emission factors for marine transportation

    NASA Astrophysics Data System (ADS)

    Alföldy, B.; Balzani Lööv, J.; Lagler, F.; Mellqvist, J.; Berg, N.; Beecken, J.; Weststrate, H.; Duyzer, J.; Bencs, L.; Horemans, B.; Cavalli, F.; Putaud, J.-P.; Janssens-Maenhout, G.; Pintér Csordás, A.; Van Grieken, R.; Borowiak, A.; Hjorth, J.

    2012-12-01

    The chemical composition of the plumes of seagoing ships was investigated during a two weeks long measurement campaign in the port of Rotterdam, Hoek van Holland, The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg-1 fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg-1 fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factor. The intercept of the regression line, 0.5 × 1016 (kg fuel)-1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.

  16. Spectroscopic measurement of impurity transport coefficients and penetration efficiencies in Alcator C-Mod plasmas

    NASA Astrophysics Data System (ADS)

    Graf, M. A.; Rice, J. E.; Terry, J. L.; Marmar, E. S.; Goetz, J. A.; McCracken, G. M.; Bombarda, F.; May, M. J.

    1995-01-01

    Impurity transport coefficients and the penetration efficiencies of intrinsic and injected impurities through the separatrix of diverted Alcator C-Mod discharges have been measured using x-ray and vacuum ultraviolet (VUV) spectroscopic diagnostics. The dominant low Z intrinsic impurity in C-Mod is carbon which is found to be present in concentrations of less than 0.5%. Molybdenum, from the plasma facing components, is the dominant high Z impurity and is typically found in concentrations of about 0.02%. Trace amounts of medium and high Z nonrecycling impurities can be injected at the midplane using the laser blow-off technique and calibrated amounts of recycling, gaseous impurities can be introduced through fast valves either at the midplane or at various locations in the divertor chamber. A five chord crystal x-ray spectrometer array with high spectral resolution is used to provide spatial profiles of high charge state impurities. An absolutely calibrated, grazing incidence VUV spectrograph with high time resolution and a broad spectral range allows for the simultaneous measurement of many impurity lines. Various filtered soft x-ray diode arrays allow for spatial reconstructions of plasma emissivity. The observed brightnesses and emissivities from a number of impurity lines are used together with the mist transport code and a collisional-radiative atomic physics model to determine charge state density profiles and impurity transport coefficients. Comparisons of the deduced impurity content with the measured Zeff and total radiated power of the plasma are made.

  17. Tabulated pressure measurements on an executive-type jet transport model with a supercritical wing

    NASA Technical Reports Server (NTRS)

    Bartlett, D. W.

    1975-01-01

    A 1/9 scale model of an existing executive type jet transport refitted with a supercritical wing was tested on in the 8 foot transonic pressure tunnel. The supercritical wing had the same sweep as the original airplane wing but had maximum thickness chord ratios 33 percent larger at the mean geometric chord and almost 50 percent larger at the wing-fuselage juncture. Wing pressure distributions and fuselage pressure distributions in the vicinity of the left nacelle were measured at Mach numbers from 0.25 to 0.90 at angles of attack that generally varied from -2 deg to 10 deg. Results are presented in tabular form without analysis.

  18. VOLUME 78, NUMBER 11 P H Y S I C A L R E V I E W L E T T E R S 17 MARCH 1997 Test Particle Transport due to Long Range Interactions

    E-print Network

    California at San Diego, University of

    VOLUME 78, NUMBER 11 P H Y S I C A L R E V I E W L E T T E R S 17 MARCH 1997 Test Particle-field transport of test particles is observed in a quiescent, steady-state pure ion plasma. The measured particle-9007(97)02594-5] PACS numbers: 52.25.Fi, 52.25.Wz Collisional transport of particles and energy across magnetic field

  19. Phase Measurement of Galvanneal Task JPL Task Order Number: RF-152 Amendment Number: 543

    SciTech Connect

    Lynn Lowry; Beverly Tai

    1995-03-01

    The objective of this task was to demonstrate an x-ray fluorescence (XRF) technique which would measure the phase composition of galvanneal coatings of sheet steel rapidly and non-destructively with an accuracy of 0.5%. This data acquisition and analysis method would be implemented as an on-line process control input. The AISI sample matrix evaluated for this study is shown in Appendix I. The Jet Propulsion Laboratory (JPL) and Data Measurement Corporation (DMC) measured iron and zinc XRF responses from these samples. In addition, JPL performed metallograph, x-ray diffraction (XRD), and transmission electron microscopy (TEM) to characterize the samples' galvanneal phase morphology. This data was correlated with the XRF experimental results and then compared to phase composition models, which were generated using a Fundamental Parameters Method (FPM) approach.

  20. Temperature Measurement and Phonon Number Statistics of a Nanoelectromechanical Resonator

    E-print Network

    O. P. de Sá Neto; M. C. de Oliveira; G. J. Milburn

    2015-08-07

    Measuring thermodynamic quantities can be easy or not, depending on the system that is being studied. For a macroscopic object, measuring temperatures can be as simple as measuring how much a column of mercury rises when in contact with the object. At the small scale of quantum electromechanical systems, such simple methods are not available and invariably detection processes disturb the system state. Here we propose a method for measuring the temperature on a suspended semiconductor membrane clamped at both ends. In this method, the membrane is mediating a capacitive coupling between two transmission line resonators (TLR). The first TLR has a strong dispersion, that is, its decaying rate is larger than its drive, and its role is to pump in a pulsed way the interaction between the membrane and the second TLR. By averaging the pulsed measurements of the quadrature of the second TLR we show how the temperature of the membrane can be determined. Moreover the statistical description of the state of the membrane, which is directly accessed in this approach is significantly improved by the addition of a Josephson Junction coupled to the second TLR.

  1. Relationship between Objectively Measured Transportation Behaviors and Health Characteristics in Older Adults

    PubMed Central

    Takemoto, Michelle; Carlson, Jordan A.; Moran, Kevin; Godbole, Suneeta; Crist, Katie; Kerr, Jacqueline

    2015-01-01

    This study used objective Global Positioning Systems (GPS) to investigate the relationship between pedestrian and vehicle trips to physical, cognitive, and psychological functioning in older adults living in retirement communities. Older adults (N = 279; mean age = 83 ± 6 years) wore a GPS and accelerometer for 6 days. Participants completed standard health measures. The Personal Activity and Location Measurement System (PALMS) was used to calculate the average daily number of trips, distance, and minutes traveled for pedestrian and vehicle trips from the combined GPS and accelerometer data. Linear mixed effects regression models explored relationships between these transportation variables and physical, psychological and cognitive functioning. Number, distance, and minutes of pedestrian trips were positively associated with physical and psychological functioning but not cognitive functioning. Number of vehicle trips was negatively associated with fear of falls; there were no other associations between the vehicle trip variables and functioning. Vehicle travel did not appear to be related to functioning in older adults in retirement communities except that fear of falling was related to number of vehicle trips. Pedestrian trips had moderate associations with multiple physical and psychological functioning measures, supporting a link between walking and many aspects of health in older adults. PMID:26528999

  2. Relationship between Objectively Measured Transportation Behaviors and Health Characteristics in Older Adults.

    PubMed

    Takemoto, Michelle; Carlson, Jordan A; Moran, Kevin; Godbole, Suneeta; Crist, Katie; Kerr, Jacqueline

    2015-01-01

    This study used objective Global Positioning Systems (GPS) to investigate the relationship between pedestrian and vehicle trips to physical, cognitive, and psychological functioning in older adults living in retirement communities. Older adults (N = 279; mean age = 83 ± 6 years) wore a GPS and accelerometer for 6 days. Participants completed standard health measures. The Personal Activity and Location Measurement System (PALMS) was used to calculate the average daily number of trips, distance, and minutes traveled for pedestrian and vehicle trips from the combined GPS and accelerometer data. Linear mixed effects regression models explored relationships between these transportation variables and physical, psychological and cognitive functioning. Number, distance, and minutes of pedestrian trips were positively associated with physical and psychological functioning but not cognitive functioning. Number of vehicle trips was negatively associated with fear of falls; there were no other associations between the vehicle trip variables and functioning. Vehicle travel did not appear to be related to functioning in older adults in retirement communities except that fear of falling was related to number of vehicle trips. Pedestrian trips had moderate associations with multiple physical and psychological functioning measures, supporting a link between walking and many aspects of health in older adults. PMID:26528999

  3. Measurement of Instantaneous Velocity Vectors of Organelle Transport: Mitochondrial Transport and Bioenergetics in Hippocampal Neurons

    PubMed Central

    Gerencser, Akos A.; Nicholls, David G.

    2008-01-01

    Impaired transport of mitochondria, in dendrites and axons of neurons, and bioenergetic deficit are increasingly recognized to be of pathological importance in neurodegenerative diseases. To study the relationship between transport and bioenergetics, we have developed what to our knowledge is a novel technique to quantify organelle velocity in cultured cells. The aim was to combine measurement of motion and bioenergetic parameters while minimizing photodynamic oxidative artifacts evoked by fluorescence excitation. Velocity determination from sequential fluorescence images is not trivial, and here we describe an application of “optical flow”, the flow of gray values in grayscale images, to this problem. Based on the principles of photon shot noise occurring in low light level fluorescence microscopy, we describe and validate here an optical flow-based, robust method to measure velocity vectors for organelles expressing fluorescent proteins. This method features instantaneous velocity determination from a pair of images by detecting motion of edges, with no assumptions about the separation or shapes of the objects in the image. Optical flow was used in combination with single mitochondrion assay of mitochondrial thiol redox status by mitochondrially targeted redox-sensitive green fluorescent protein and measurement of mitochondrial membrane potential by tetramethylrhodamine methyl ester. Mitochondrial populations of resting cultured hippocampal neurons were analyzed. It was found that mitochondria with more oxidized thiol redox status have lower membrane potentials and are smaller in size. These mitochondria are more motile than the average; however, mitochondrial motility is only slightly dependent on the observed bioenergetic parameters and is correlated the best to the size of the mitochondria. PMID:18757564

  4. A critical analysis of sketch-planning tools for evaluating the emissions benefits of transportation control measures 

    E-print Network

    Crawford, Jason Aaron

    1993-01-01

    The role of transportation control measures (TCMS) in the transportation planning process has increased since the passage of the 1990 Clean Air Act Amendments. Transportation control measure analysis began in the early ...

  5. Peclet number as affected by molecular diffusion controls transient anomalous transport in alluvial aquifer-aquitard complexes

    USGS Publications Warehouse

    Zhang, Yong; Green, Christopher T.; Tick, Geoffrey R.

    2015-01-01

    This study evaluates the role of the Peclet number as affected by molecular diffusion in transient anomalous transport, which is one of the major knowledge gaps in anomalous transport, by combining Monte Carlo simulations and stochastic model analysis. Two alluvial settings containing either short- or long-connected hydrofacies are generated and used as media for flow and transport modeling. Numerical experiments show that 1) the Peclet number affects both the duration of the power-law segment of tracer breakthrough curves (BTCs) and the transition rate from anomalous to Fickian transport by determining the solute residence time for a given low-permeability layer, 2) mechanical dispersion has a limited contribution to the anomalous characteristics of late-time transport as compared to molecular diffusion due to an almost negligible velocity in floodplain deposits, and 3) the initial source dimensions only enhance the power-law tail of the BTCs at short travel distances. A tempered stable stochastic (TSS) model is then applied to analyze the modeled transport. Applications show that the time-nonlocal parameters in the TSS model relate to the Peclet number, Pe. In particular, the truncation parameter in the TSS model increases nonlinearly with a decrease in Pe due to the decrease of the mean residence time, and the capacity coefficient increases with an increase in molecular diffusion which is probably due to the increase in the number of immobile particles. The above numerical experiments and stochastic analysis therefore reveal that the Peclet number as affected by molecular diffusion controls transient anomalous transport in alluvial aquifer–aquitard complexes.

  6. Measuring and controlling the transport of magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Stephens, Jason R.

    Despite the large body of literature describing the synthesis of magnetic nanoparticles, few analytical tools are commonly used for their purification and analysis. Due to their unique physical and chemical properties, magnetic nanoparticles are appealing candidates for biomedical applications and analytical separations. Yet in the absence of methods for assessing and assuring their purity, the ultimate use of magnetic particles and heterostructures is likely to be limited. For magnetic nanoparticles, it is the use of an applied magnetic flux or field gradient that enables separations. Flow based techniques are combined with applied magnetic fields to give methods such as magnetic field flow fractionation and high gradient magnetic separation. Additional techniques have been explored for manipulating particles in microfluidic channels and in mesoporous membranes. This thesis further describes development of these and new analytical tools for separation and analysis of colloidal particles is critically important to enable the practical use of these, particularly for medicinal purposes. Measurement of transport of nanometer scale particles through porous media is important to begin to understand the potential environmental impacts of nanomaterials. Using a diffusion cell with two compartments separated by either a porous alumina or polycarbonate membrane as a model system, diffusive flux through mesoporous materials is examined. Experiments are performed as a function of particle size, pore diameter, and solvent, and the particle fluxes are monitored by the change in absorbance of the solution in the receiving cell. Using the measured extinction coefficient and change in absorbance of the solution as a function of time, the fluxes of 3, 8, and 14 nm diameter CoFe2O4 particles are determined as they are translocated across pores with diameters 30, 50, 100, and 200 nm in hexane and aqueous solutions. In general, flux decreases with increasing particle size and increases with pore diameter. We find that fluxes are faster in aqueous solutions than in hexane, which is attributed to the hydrophilic nature of the porous membranes and differences in wettability. The impact of an applied magnetic flux gradient, which induces magnetization and motion, on permeation is also examined. Surface chemistry plays an important role in determining flux through porous media such as in the environment. Diffusive flux of nanoparticles through alkylsilane modified porous alumina is measured as a model for understanding transport in porous media of differing surface chemistries. Experiments are performed as a function of particle size, pore diameter, attached hydrocarbon chain length and chain terminus, and solvent. Particle fluxes are monitored by the change in absorbance of the solution in the receiving side of a diffusion cell. In general, flux increases when the membranes are modified with alkylsilanes compared to untreated membranes, which is attributed to the hydrophobic nature of the porous membranes and differences in wettability. We find that flux decreases, in both hexane and aqueous solutions, when the hydrocarbon chain lining the interior pore wall increases in length. The rate and selectivity of transport across these membranes is related to the partition coefficient (Kp) and the diffusion coefficient (D) of the permeating species. By conducting experiments as a function of initial particle concentration, we find that KpD increases with increasing particle size, is greater in alkylsilane--modified pores, and larger in hexane solution than water. The impact of the alkylsilane terminus (--CH3, --Br, --NH2, --COOH) on permeation in water is also examined. In water, the highest KpD is observed when the membranes are modified with carboxylic acid terminated silanes and lowest with amine terminated silanes as a result of electrostatic effects during translocation. Finally, the manipulation of magnetic nanoparticles for the controlled formation of linked nanoparticle assemblies between microfluidic channels by the application of an external

  7. A Transportation Network EfficiencyA Transportation Network Efficiency Measure that Captures Flows,Measure that Captures Flows,

    E-print Network

    Nagurney, Anna

    Earthquake Damage prcs.org.pkprcs.org.pk Tsunami letthesunshinein.wordpress.com Storm Damage www to reinforce/enhance security. #12;Transportation Network EquilibriumTransportation Network Equilibrium

  8. A Transportation Network EfficiencyA Transportation Network Efficiency Measure that Captures Flows, Behavior,Measure that Captures Flows, Behavior,

    E-print Network

    Nagurney, Anna

    letthesunshinein.wordpress.com Storm Damage www.srh.noaa.gov Infrastructure Collapse www.10-7.com #12;An Urgent/enhance security. #12;Transportation Network EquilibriumTransportation Network Equilibrium ParadigmParadigm It has

  9. Aircraft Measurements of Saharan dust properties and impact of atmospheric transport during Fennec

    NASA Astrophysics Data System (ADS)

    Ryder, Claire; Highwood, Ellie; Rosenberg, Phil; Trembath, Jamie; Brooke, Jennifer; Bart, Mark; Dean, Angela; Dorsey, James; Crosier, Jonny; McQuaid, Jim; Brindley, Helen; Banks, James; Marsham, John; Sodemann, Harald; Washington, Richard

    2013-04-01

    Measurements of Saharan dust from recent airborne campaigns have found variations in size distributions and optical properties across Saharan and sub-Saharan Africa. These variations have an impact on radiation and thus weather and climate, and are important to characterise and understand, in particular, to understand how they vary with time after dust uplift, transport, and height in the atmosphere. New in-situ aircraft measurements from the Fennec 2011 aircraft campaign over a remote part of the Sahara Desert and the Atlantic Ocean will be presented and compared to previous airborne measurements. Size distributions extending to 300 ?m will be shown, representing measurements extending further into the coarse mode than previously published for Saharan dust. The dust sampled by the aircraft covered a wide variety of loadings, dust source regions (Mali, Mauritania and Algeria) and dust ages (from fresh uplift to several days old). A significant coarse mode was present in the size distribution measurements with effective diameter up to 23 ?m, and the mean size distribution showed greater concentrations of coarse mode than previous aircraft measurements. Single scattering albedo (SSA) values at 550nm calculated from these size distributions revealed high absorption from 0.77 to 0.95, with a mean of 0.85. Directly measured SSA values were higher (0.91 to 0.99) but new instrumentation revealed that these direct measurements, behind Rosemount inlets, overestimate the SSA by 0.02 to 0.20 depending on the concentration of coarse particles present. This is caused by inlet inefficiencies and pipe losses. Previous measurements of SSA from aircraft measurements may also have been overestimates for this reason. This has a significant impact on atmospheric heating rates. The largest dust particles were encountered closest to the ground, and were most abundant in cases where dust was freshly uplifted. Number concentration, mass loading and extinction coefficient showed inverse relationships to dust age, and showed some sensitivity to the type of uplift for cases of fresh dust. Vertical profiles of dust are found to be significantly different for freshly uplifted dust, aged dust, and dust transported over the ocean. Consequently, changes in the optical properties during dust transport are observed.

  10. Direct measurements of the outer membrane stage of ferric enterobactin transport: postuptake binding.

    PubMed

    Newton, Salete M; Trinh, Vy; Pi, Hualiang; Klebba, Phillip E

    2010-06-01

    When Gram-negative bacteria acquire iron, the metal crosses both the outer membrane (OM) and the inner membrane, but existing radioisotopic uptake assays only measure its passage through the latter bilayer, as the accumulation of the radionuclide in the cytoplasm. We devised a methodology that exclusively observes OM transport and used it to study the uptake of ferric enterobactin (FeEnt) by Escherichia coli FepA. This technique, called postuptake binding, revealed previously unknown aspects of TonB-dependent transport reactions. The experiments showed, for the first time, that despite the discrepancy in cell envelope concentrations of FepA and TonB ( approximately 35:1), all FepA proteins were active and equivalent in FeEnt uptake, with a maximum turnover number of approximately 5/min. FepA-mediated transport of FeEnt progressed through three distinct phases with successively decreasing rates, and from its temperature dependence, the activation energy of the OM stage was 33-35 kcal/mol. The accumulation of FeEnt in the periplasm required the binding protein and inner membrane permease components of its overall transport system; postuptake binding assays on strains devoid of FepB, FepD, or FepG did not show uptake of FeEnt through the OM. However, fluorescence labeling data implied that FepA was active in the DeltafepB strain, suggesting that FeEnt entered the periplasm but then leaked out. Further experiments confirmed this futile cycle; cells without FepB transported FeEnt across the OM, but it immediately escaped through TolC. PMID:20335169

  11. Measurements and modeling of deposited particle transport by foot traffic indoors.

    PubMed

    Sippola, Mark R; Sextro, Richard G; Thatcher, Tracy L

    2014-04-01

    Deposited particles are transported into and within buildings by adhering to and releasing from people's shoes. To better understand transport of deposited particulate contaminants and exposures to these materials, experimental data on tracking by foot traffic are needed. Laboratory experiments measured uptake and downlay mass transfer efficiencies of particles between shoes and floors in a step-simulation chamber. Equilibrium uptake transfer fractions, the net mass fraction transferred from floors to shoes after several steps, were also measured. Single-step uptake and downlay transfer efficiencies ranged from 0.02 to 0.22 and equilibrium uptake transfer fractions were 0.10-0.40. Particle size, particle loading, shoe type, floor type, step pressure, and step sequence were all investigated. Experiments demonstrated that single-step downlay transfer efficiencies decrease with each successive step onto clean floors. A simple empirical model is proposed to estimate these transfers as a function of step number. Simulations using the transfer efficiency values measured here illustrate the spread of deposited particles by people walking in a hypothetical hallway. These simulations show that in locations where a few people walk over the same area each minute, tracking can spread deposited material over length scales comparable to building dimensions in just a few hours. PMID:24579974

  12. On Um -numbers with small transcendence measure Kamil Alnia cik, Yusuf Avci (Istanbul)

    E-print Network

    Bugeaud, Yann

    ) The purpose of the present note is to present a new, e#11;ective method for constructing real Um -numbers #24 Proposition 1 below is e#11;ective. It is expected that there exist Um -numbers #24; with w #3; n (#24;) = nOn Um -numbers with small transcendence measure Kamil Alnia#24;cik, Yusuf Avci (Istanbul) & Yann

  13. A framework for operationalization of strategic plans and metrics for corporate performance measurement in transportation asset management

    NASA Astrophysics Data System (ADS)

    Mteri, Hassan H.

    This thesis investigated the business processes required to translate corporate-level strategic plans into tactical and operational plans in the context of transportation asset management. The study also developed a framework for effective performance measure for departments of transportation. The thesis was based on a case study of transportation agencies in the U.S.A. and Canada. The scope is therefore limited or more directly applicable to transportation assets such as pavement, bridges and culverts. The goal was to address the problem of translating or managing strategic plans, especially in the context of the public sector responsible for operating transportation infrastructure. It was observed that many agencies have been successful in formulating good strategic plans but they have performed relatively poorly in translating such corporate-level strategic plans into operational activities. A questionnaire survey was designed and targeted about 30 state agencies that are currently active in transportation asset management. Twenty one (21) transportation agencies in the USA and Canada responded to the questionnaire. The analysis of the questionnaire data showed that there is a lack of a standard approach to managing corporate strategic plans in transportation agencies. The results also indicated that most transportation agencies operate in three organizational levels but there was no systematic approach of translating goal and objectives from high level to lower levels. Approaches in performance measurement were found to vary from agency to agency. A number of limitations were identified in the existing practice on performance measurements. Key weaknesses include the large number of measures in use (as many as 25 or more), and the disconnection between the measures used and the corporate goals and objectives. Lessons from the private sector were thoroughly reviewed in order to build the groundwork for adapting existing tools to the public sector. The existing literature, assumptions and characteristics that make the Balanced Scorecards and strategy maps work effectively in the private sector were identified. Gaps in implementation of strategic plans and the use of Balanced Scorecard in the public sector were derived. Although Balanced Scorecards have previously been used to a limited extent in transportation agencies, the use of combined Balanced Scorecards and strategy maps with a much broader utility of translating strategic plans into tactical and operational activities for Transportation Asset Management is yet to be established. The thesis presents a framework to operationalize strategic plans through the combined application of Balanced Scorecards and strategy maps. The proposed framework aligns overarching objectives in all organizational levels: corporate, tactical, and operation, in which detail information is delegated from top level to lower levels. Furthermore, the thesis presents a proposed framework for developing and using effective corporate performance measures. The framework for performance measures provides a key tool for tracking progress and ensuring overall operationalization of strategic plans in transportation agencies. The thesis presents a methodology to assess existing performance measures so that agencies can reduce the number of measures, to be more effective and manageable. It was found that among other good characteristics, corporate performance measures must be tied to agency's goals and objectives and must be sensitive or responsive to program delivery activities and to the impacts of decisions about resource allocation.

  14. Magnetorotational Turbulence Transports Angular Momentum in Stratified Disks with Low Magnetic Prandtl Number but Magnetic Reynolds Number above a Critical Value

    SciTech Connect

    Oishi, Jeffrey S.; Low, Mordecai-Mark Mac; /Amer. Museum Natural Hist.

    2012-02-14

    The magnetorotational instability (MRI) may dominate outward transport of angular momentum in accretion disks, allowing material to fall onto the central object. Previous work has established that the MRI can drive a mean-field dynamo, possibly leading to a self-sustaining accretion system. Recently, however, simulations of the scaling of the angular momentum transport parameter {alpha}{sub SS} with the magnetic Prandtl number Pm have cast doubt on the ability of the MRI to transport astrophysically relevant amounts of angular momentum in real disk systems. Here, we use simulations including explicit physical viscosity and resistivity to show that when vertical stratification is included, mean field dynamo action operates, driving the system to a configuration in which the magnetic field is not fully helical. This relaxes the constraints on the generated field provided by magnetic helicity conservation, allowing the generation of a mean field on timescales independent of the resistivity. Our models demonstrate the existence of a critical magnetic Reynolds number Rm{sub crit}, below which transport becomes strongly Pm-dependent and chaotic, but above which the transport is steady and Pm-independent. Prior simulations showing Pm-dependence had Rm < Rm{sub crit}. We conjecture that this steady regime is possible because the mean field dynamo is not helicity-limited and thus does not depend on the details of the helicity ejection process. Scaling to realistic astrophysical parameters suggests that disks around both protostars and stellar mass black holes have Rm >> Rm{sub crit}. Thus, we suggest that the strong Pm dependence seen in recent simulations does not occur in real systems.

  15. MAGNETOROTATIONAL TURBULENCE TRANSPORTS ANGULAR MOMENTUM IN STRATIFIED DISKS WITH LOW MAGNETIC PRANDTL NUMBER BUT MAGNETIC REYNOLDS NUMBER ABOVE A CRITICAL VALUE

    SciTech Connect

    Oishi, Jeffrey S.

    2011-10-10

    The magnetorotational instability (MRI) may dominate outward transport of angular momentum in accretion disks, allowing material to fall onto the central object. Previous work has established that the MRI can drive a mean-field dynamo, possibly leading to a self-sustaining accretion system. Recently, however, simulations of the scaling of the angular momentum transport parameter {alpha}{sub SS} with the magnetic Prandtl number Pm have cast doubt on the ability of the MRI to transport astrophysically relevant amounts of angular momentum in real disk systems. Here, we use simulations including explicit physical viscosity and resistivity to show that when vertical stratification is included, mean-field dynamo action operates, driving the system to a configuration in which the magnetic field is not fully helical. This relaxes the constraints on the generated field provided by magnetic helicity conservation, allowing the generation of a mean field on timescales independent of the resistivity. Our models demonstrate the existence of a critical magnetic Reynolds number Rm{sub crit}, below which transport becomes strongly Pm-dependent and chaotic, but above which the transport is steady and Pm-independent. Prior simulations showing Pm dependence had Rm < Rm{sub crit}. We conjecture that this steady regime is possible because the mean-field dynamo is not helicity-limited and thus does not depend on the details of the helicity ejection process. Scaling to realistic astrophysical parameters suggests that disks around both protostars and stellar mass black holes have Rm >> Rm{sub crit}. Thus, we suggest that the strong Pm dependence seen in recent simulations does not occur in real systems.

  16. VOLUME 60, NUMBER 20 PHYSICAL REVIEW LETTERS 16 MAY 1988 Mass Transport in Propagating Patterns of Convection

    E-print Network

    Moses, Elisha

    of Convection Elisha Moses Department of Physics, Weizmann Institute, Rehovot, Israel and Victor Steinberg observation of convective transport in oscillatory convection of a binary mixture. The results show. PACS numbers: 47.25.Jn Extensive studies of oscillatory convection in binary mixtures have recently

  17. Functional requirements for the Automated Transportation Management System: TTP number: RL 439002

    SciTech Connect

    Portsmouth, J.H.

    1992-12-31

    This requirements analysis, documents Department of Energy (DOE) transportation management procedures for the purpose of providing a clear and mutual understanding between users and designers of the proposed Automated Transportation Management System (ATMS). It is imperative that one understand precisely how DOE currently performs traffic management tasks; only then can an integrated system be proposed that successfully satisfies the major requirements of transportation managers and other system users. Accordingly, this report describes the current workings of DOE transportation organizations and then proposes a new system which represents a synthesis of procedures (both current and desired) which forms the basis for further systems development activities.

  18. Charge Transport Measurements at the Nanoscale using a Multi-Tip STM

    E-print Network

    Ku?el, Petr

    Charge Transport Measurements at the Nanoscale using a Multi-Tip STM Seminá odd. 26 Tenkých vrstev an ultra-compact, ultra-stable four-tip STM for charge transport measurements at the nanoscale for novel semiconductor devices in future electronic and opto-electronic applications such as solar cells

  19. Combining impact sensor field and laboratory flume measurements with other techniques for studying fluvial bedload transport in steep mountain streams

    NASA Astrophysics Data System (ADS)

    Beylich, Achim A.; Laute, Katja

    2014-08-01

    The timing and rate of fluvial bedload transport are of central importance within sediment budget studies and in many applications in river science and engineering. During the years 2010, 2011 and 2012 detailed field measurements with portable impact sensors as a non-invasive technique for indirectly determining fluvial bedload transport intensity were conducted in two instrumented and supply-limited drainage basin systems (Erdalen and Bødalen) in the fjord landscape in western Norway. Additional field measurements with portable impact sensors were carried out in 2010 and 2011 in selected transport-limited fluvial systems in the Coast Mountains of western Canada. The collected impact sensor field data were calibrated with laboratory flume experiments. The data from the impact sensor field measurements in western Norway and the flume experiments were combined with field data from continuous discharge monitoring, repeated surveys of channel morphometry and sediment texture, particle tracer measurements, Helley-Smith samplings, underwater video filming and biofilm analyses. The combination of methods and techniques applied provides insights into the temporal variability and intensity of fluvial bedload transport in the selected mountain streams: (i) in the transport-limited systems with generally high bedload transport rates during high discharge and with bedload material moving in clusters over the impact sensor plates, impact sensor data (based on a 1 s measuring interval) provide the opportunity to detect the start and end of bedload transport, thus to identify discharge thresholds for sediment entrainment, and to roughly estimate the intensity and relative intensity of change of bedload transport during the measuring period; (ii) in the supply-limited systems with low bedload transport rates and bedload components moving separately (as single particles) over the impact sensor plates, impact sensor data (with a 1 s measuring interval) allow the detection of the start and end of transport of bedload components > 11.3 mm, thus the identification of discharge thresholds for possible entrainment of particles, the quantification of the number of particles > 11.3 mm moving over the impact sensor plates during the measuring period, the rough estimation of grain sizes of the particles moving separately over the impact sensor plates, and the calculation of the total mass of the bedload material > 11.3 mm moving over the impact sensor plates during the measuring period; (iii) when combined with other methods and techniques (Helley-Smith sampling, particle tracer measurements, biofilm analyses, underwater video filming) which provide information on the active bedload transport channel width, on discharge thresholds for possible entrainment of particles of different grain sizes, and on transport rates of bedload material < 11.3 mm, total rates of fluvial bedload transport, covering all given grain sizes of the bedload material, can be calculated for the supply-limited mountain streams with generally low bedload transport. The higher measured annual bedload yield in Bødalen (13.6 t km- 2 yr- 1) compared to Erdalen (2.6 t km- 2 yr- 1) reflects a higher level of slope-channel coupling in Bødalen than in Erdalen.

  20. A Transportation Network Efficiency Measure that Captures Flows, Behavior,

    E-print Network

    Nagurney, Anna

    .org.pk Tsunami letthesunshinein.wordpress.com Storm Damage www.srh.noaa.gov Infrastructure Collapse www.10-7.com of network vulnerabilities as well as when to reinforce/enhance security. #12;Transportation Network

  1. Indicators that matter : measuring transportation performance in Ahmedabad

    E-print Network

    Osborne, James Clark, M.C.P. Massachusetts Institute of Technology

    2012-01-01

    In light of the growing challenges of planning for transportation in India, this thesis proposes that a set of indicators, sensitive to local conditions, developed, implemented and managed through a collaborative partnership ...

  2. Measuring the Value of Time in Highway Freight Transportation 

    E-print Network

    Miao, Qing

    2014-01-13

    This research investigated several aspects of the value of time (VOT) in the trucking industry. This included examining the marginal monetary benefits and costs of reduced and prolonged freight transportation time on highways. First, a...

  3. Accumulationmode aerosol number concentrations in the Arctic during the ARCTAS aircraft campaign: Longrange transport

    E-print Network

    Jimenez, Jose-Luis

    , this cleansing effect will be prominent for air transported via WCBs from other midlatitude regions and seasons of efficient transport of pollutants from midlatitudes and slow removal processes in these seasons [Barrie of Meteorology, Florida State University, Tallahassee, Florida, USA. 6 Chemistry and Dynamics Branch, NASA

  4. Apparatus for the measurement of radionuclide transport rates in rock cores

    SciTech Connect

    Weed, H.C.; Koszykowski, R.F.; Dibley, L.L.; Murray, I.

    1981-09-01

    An apparatus and procedure for the study of radionuclide transport in intact rock cores are presented in this report. This equipment more closely simulates natural conditions of radionuclide transport than do crushed rock columns. The apparatus and the procedure from rock core preparation through data analysis are described. The retardation factors measured are the ratio of the transport rate of a non-retarded radionuclide, such as /sup 3/H, to the transport rate of a retarded radionuclide. Sample results from a study of the transport of /sup 95m/Tc and /sup 85/Sr in brine through a sandstone core are included.

  5. Inverse constraints for emission fluxes of atmospheric tracers estimated from concentration measurements and Lagrangian transport

    NASA Astrophysics Data System (ADS)

    Pisso, Ignacio; Patra, Prabir; Breivik, Knut

    2015-04-01

    Lagrangian transport models based on times series of Eulerian fields provide a computationally affordable way of achieving very high resolution for limited areas and time periods. This makes them especially suitable for the analysis of point-wise measurements of atmospheric tracers. We present an application illustrated with examples of greenhouse gases from anthropogenic emissions in urban areas and biogenic emissions in Japan and of pollutants in the Arctic. We asses the algorithmic complexity of the numerical implementation as well as the use of non-procedural techniques such as Object-Oriented programming. We discuss aspects related to the quantification of uncertainty from prior information in the presence of model error and limited number of observations. The case of non-linear constraints is explored using direct numerical optimisation methods.

  6. Predicting the vertical distribution of particle number concentration using the 3-D regional CTM PMCAMx-UF: relevance of high altitude nucleation and transport and cloud properties

    NASA Astrophysics Data System (ADS)

    Baranizadeh, Elham; Murphy, benjamin; Ahlm, Lars; Fountoukis, Christos; Pandis, Spyros; Virtanen, Annele; Lehtinen, Kari; Laaksonen, Ari; Riipinen, Ilona

    2015-04-01

    The three-dimensional chemical transport model PMCAMx-UF was used to predict the aerosol number concentrations (N) over the Europe domain during May 2008. We implemented the more sophisticated approach called Tropospheric Ultra-Violet and Visible (TUV) radiative transfer model (NCAR, 2011) to treat the cloud effect on photolysis rates. The changes in Sulfuric Acid and particles number concentrations anticorrelate at the ground level (and below clouds) while correlate above clouds. This is because updated version of the model including TUV module simulates higher radiation above the clouds resulting in stronger new particle formation in higher altitudes which are eventually transported to lower levels. For example, mean-percent-differences are 9 and -41 % in N3 and H2SO4, respectively, below clouds (cloudy regions with cloud optical depth ? >50 was chosen) and 12 and 210 % above cloud at May 5, 2008 12:00 UTC. The vertical profiles of particle number concentrations were evaluated against the measured data from EUCAARI-LONGREX campaign. Results indicate that the model is slightly overestimating the particles in nucleation mode range over the ground-level altitudes. However, the model shows a significant agreement with the measurements for the N4 (i.e. particles larger than 4 nm) and also N10 over all altitude levels.

  7. Transportation energy strategy: Project {number_sign}5 of the Hawaii Energy Strategy Development Program

    SciTech Connect

    1995-08-01

    This study was prepared for the State Department of Business, Economic Development and Tourism (DBEDT) as part of the Hawaii Energy Strategy program. Authority and responsibility for energy planning activities, such as the Hawaii Energy Strategy, rests with the State Energy Resources Coordinator, who is the Director of DBEDT. Hawaii Energy Strategy Study No. 5, Transportation Energy Strategy Development, was prepared to: collect and synthesize information on the present and future use of energy in Hawaii`s transportation sector, examine the potential of energy conservation to affect future energy demand; analyze the possibility of satisfying a portion of the state`s future transportation energy demand through alternative fuels; and recommend a program targeting energy use in the state`s transportation sector to help achieve state goals. The analyses and conclusions of this report should be assessed in relation to the other Hawaii Energy Strategy Studies in developing a comprehensive state energy program. 56 figs., 87 tabs.

  8. Measurement of three-dimensional coherent fluid structure in high Reynolds number turbulent boundary layers

    E-print Network

    Clark, Thomas Henry

    2012-07-03

    solution tech- nique). ppp Number of Particles Per Pixel (particle density within im- ages). *RELAX RELAXation based algorithm used to apply POCS constraints. 3D3C 3-Dimensional, 3-Component [velocity measurements]. AEM Attached Eddy Model. CFD... above ?+=800. As Reynolds Number increases, the separation (in size) be- tween the smallest and largest turbulent eddies in a flow increases. Thus, for a given largest eddy (set by the boundary layer size), increasing the Reynolds Number requires a finer...

  9. Scanner and kVp dependence of measured CT numbers in the ACR CT phantom.

    PubMed

    Cropp, Robert J; Seslija, Petar; Tso, David; Thakur, Yogesh

    2013-01-01

    Quality control testing of CT scanners in our region includes a measurement of CT numbers in the American College of Radiology (ACR) CT phantom using a standardized protocol. CT number values are clinically relevant in determining the composition of various tissues in the body. Accuracy is important in the characterization of tumors, assessment of coronary calcium, and identification of urinary stone composition. Effective quality control requires that tolerance ranges of CT number values be defined: a measured value outside the range indicates the need for further investigation and possible recalibration of the scanner. This paper presents the results of CT number measurements on 36 scanners (25 GE, 10 Siemens and 1 Toshiba) at each available kVp. Among the five materials (solid water, air, polyethylene, acrylic, bone-equivalent) the measured CT numbers exhibit manufacturer and kVp dependence, which should be taken into account when defining tolerances. With this scan protocol, air and solid water values are significantly higher on GE scanners than on Siemens scanners (p-value < 0.01 at each kVp). The CT numbers of polyethylene and acrylic increase with kVp, while the bone-equivalent CT number decreases. These results are used to define manufacturer- and kVp-specific tolerance ranges for the CT numbers of each material in this phantom, which will be used in our quality control program. PMID:24257284

  10. CARS measurements of temperature and species number density in supersonic combusting flow

    NASA Technical Reports Server (NTRS)

    Antcliff, Richard R.; Jarrett, Olin, Jr.; Chitsomboon, Tawit; Cutler, Andrew

    1988-01-01

    A supersonic combustion burner has been probed by coherent anti-Stokes Raman Spectroscopy and the results compared with computational fluid dynamics. Simultaneous measurement of temperature, nitrogen number density and oxygen number density have been acquired throughout the external combustion region. Preliminary calculations have been made on this system to estimate the burner performance. Comparisons of these techniques are included.

  11. Measurements of the production and transport of helium ash in the TFTR tokamak

    SciTech Connect

    Synakowski, E.J.; Bell, R.E.; Budny, R.V.; Bush, C.E.; Efthimion, P.C.; Grek, B.; Johnson, D.W.; Johnson, L.C.; LeBlanc, B.; Park, H.; Ramsey, A.T.; Taylor, G.

    1995-11-13

    Helium ash production and transport have been measured in TFTR deuterium-tritium plasmas using charge-exchange recombination spectroscopy. The helium ash confinement time, including recycling effects, is 6--10 times the energy confinement time and is compatible with sustained ignition in a reactor. The ash confinement time is dominated by edge pumping rates rather than core transport. The measured evolution of the local thermal ash density is consistent with modeling based on previously measured helium transport coefficients and classical slowing down of the alpha particles. {copyright} {ital 1995} {ital The} {ital American} {ital Physical} {ital Society}.

  12. Anharmonic effects on a phonon-number measurement of a quantum-mesoscopic-mechanical oscillator

    SciTech Connect

    Santamore, D.H.; Goan Hsisheng; Milburn, G.J.; Roukes, M.L.

    2004-11-01

    We generalize a proposal for detecting single-phonon transitions in a single nanoelectromechanical system (NEMS) to include the intrinsic anharmonicity of each mechanical oscillator. In this scheme two NEMS oscillators are coupled via a term quadratic in the amplitude of oscillation for each oscillator. One NEMS oscillator is driven and strongly damped and becomes a transducer for phonon number in the other measured oscillator. We derive the conditions for this measurement scheme to be quantum limited and find a condition on the size of the anharmonicity. We also derive the relation between the phase diffusion back-action noise due to number measurement and the localization time for the measured system to enter a phonon-number eigenstate. We relate both these time scales to the strength of the measured signal, which is an induced current proportional to the position of the read-out oscillator.

  13. Distance-Based Functional Diversity Measures and Their Decomposition: A Framework Based on Hill Numbers

    PubMed Central

    Chiu, Chun-Huo; Chao, Anne

    2014-01-01

    Hill numbers (or the “effective number of species”) are increasingly used to characterize species diversity of an assemblage. This work extends Hill numbers to incorporate species pairwise functional distances calculated from species traits. We derive a parametric class of functional Hill numbers, which quantify “the effective number of equally abundant and (functionally) equally distinct species” in an assemblage. We also propose a class of mean functional diversity (per species), which quantifies the effective sum of functional distances between a fixed species to all other species. The product of the functional Hill number and the mean functional diversity thus quantifies the (total) functional diversity, i.e., the effective total distance between species of the assemblage. The three measures (functional Hill numbers, mean functional diversity and total functional diversity) quantify different aspects of species trait space, and all are based on species abundance and species pairwise functional distances. When all species are equally distinct, our functional Hill numbers reduce to ordinary Hill numbers. When species abundances are not considered or species are equally abundant, our total functional diversity reduces to the sum of all pairwise distances between species of an assemblage. The functional Hill numbers and the mean functional diversity both satisfy a replication principle, implying the total functional diversity satisfies a quadratic replication principle. When there are multiple assemblages defined by the investigator, each of the three measures of the pooled assemblage (gamma) can be multiplicatively decomposed into alpha and beta components, and the two components are independent. The resulting beta component measures pure functional differentiation among assemblages and can be further transformed to obtain several classes of normalized functional similarity (or differentiation) measures, including N-assemblage functional generalizations of the classic Jaccard, Sørensen, Horn and Morisita-Horn similarity indices. The proposed measures are applied to artificial and real data for illustration. PMID:25000299

  14. Measurement and modeling of phosphorous transport in shallow groundwater environments

    NASA Astrophysics Data System (ADS)

    Hendricks, G. S.; Shukla, S.; Obreza, T. A.; Harris, W. G.

    2014-08-01

    Leaching of phosphorus (P) from agricultural soils, especially those that are sandy, is adversely impacting P-limited ecosystems like Florida's Everglades. A more developed understanding of P and water management strategies and their effects on P leaching is needed to achieve reductions in subsurface P losses, especially from intensively managed dual cropping systems under plastic mulch in shallow water regions. We compared the effects of conservation P and water management strategies with traditional practices on P transport to groundwater. A 3-year experiment was conducted on hydrologically isolated plots with plastic-mulched successive cropping systems to compare high (HEI) and soil test based recommended (REI) external input (water and fertilizer P) systems with traditional sub-irrigation (seepage), and REI with a potential water conservation subsurface drip irrigation system (REI-SD) with regard to groundwater P concentrations above and below the low conductivity spodic horizon (Bh). The REI treatments had higher available storage for rainfall and P than HEI. Use of both REI systems (REI = 2098 ?g/L and REI-SD = 2048 ?g/L) reduced groundwater P concentrations above the Bh horizon by 33% compared to HEI (3090 ?g/L), and results were significant at the 0.05 level. Although the subsurface drip system saved water, it did not offer any groundwater quality (P) benefit. Mixing and dilution of influent P below the low conductivity Bh horizon between treatments and with the regional groundwater system resulted in no significant differences in groundwater P concentration below the Bh horizon. Groundwater P concentrations from this study were higher than reported elsewhere due to low soil P storage capacity (SPSC), high hydraulic conductivity of sandy soils, and a high water table beneath crop beds. The HEI system leached more P due to ferilizer P in excess of SPSC and used higher irrigation volumes compared with REI systems. Despite a 40% difference in the average amount of added fertilizer P between HEI (187 kg P2O5/ha) and REI (124 kg P2O5/ha), soil Mehlich 1 P (M1P) values were similar for both systems while they received Pinput. Soil M1P for REI and REI-SD increased to a maximum of 55 mg/kg while they received Pinput, and then gradually decreased after Pinput ceased. However, M1P for HEI increased steadily to a maximum of 145 mg/kg by the end of the study with continued Pinput. Mehlich-1 P measured six years after the study still showed relatively high levels of P, a legacy effect of Pinput. The main factors influencing groundwater P concentration varied by seasons. During fall with frequent rainfall, the concentrations were influenced mainly by M1P and Pinput, and highlight a need for greater focus on Pinput management (vs. water management) during this season. However, during the dry period of spring, a greater focus on irrigation management is required since depth to water table and rainfall also become contributing factors. Three multivariate models (r2 = 0.67 to 0.93), for spring, fall, and annual periods, were developed for predicting groundwater P concentrations for a wide range of water and P inputs (0 to 191 kg P2O5/ha of Pinput). The uniqueness of these models is that they use readily available hydrologic (rainfall and water table depth), management (Pinput), and soil (M1P) data commonly monitored by growers when managing water and nutrient inputs on agricultural landscapes. The development of similar models may not be necessary for other agro-ecosystems in similar regions since long-term data collected in these regions may be applied, with verification, to the models presented here.

  15. Measurement and modeling of phosphorous transport in shallow groundwater environments.

    PubMed

    Hendricks, G S; Shukla, S; Obreza, T A; Harris, W G

    2014-08-01

    Leaching of phosphorus (P) from agricultural soils, especially those that are sandy, is adversely impacting P-limited ecosystems like Florida's Everglades. A more developed understanding of P and water management strategies and their effects on P leaching is needed to achieve reductions in subsurface P losses, especially from intensively managed dual cropping systems under plastic mulch in shallow water regions. We compared the effects of conservation P and water management strategies with traditional practices on P transport to groundwater. A 3-year experiment was conducted on hydrologically isolated plots with plastic-mulched successive cropping systems to compare high (HEI) and soil test based recommended (REI) external input (water and fertilizer P) systems with traditional sub-irrigation (seepage), and REI with a potential water conservation subsurface drip irrigation system (REI-SD) with regard to groundwater P concentrations above and below the low conductivity spodic horizon (Bh). The REI treatments had higher available storage for rainfall and P than HEI. Use of both REI systems (REI=2098?g/L and REI-SD=2048?g/L) reduced groundwater P concentrations above the Bh horizon by 33% compared to HEI (3090?g/L), and results were significant at the 0.05 level. Although the subsurface drip system saved water, it did not offer any groundwater quality (P) benefit. Mixing and dilution of influent P below the low conductivity Bh horizon between treatments and with the regional groundwater system resulted in no significant differences in groundwater P concentration below the Bh horizon. Groundwater P concentrations from this study were higher than reported elsewhere due to low soil P storage capacity (SPSC), high hydraulic conductivity of sandy soils, and a high water table beneath crop beds. The HEI system leached more P due to ferilizer P in excess of SPSC and used higher irrigation volumes compared with REI systems. Despite a 40% difference in the average amount of added fertilizer P between HEI (187kg P2O5/ha) and REI (124kg P2O5/ha), soil Mehlich 1 P (M1P) values were similar for both systems while they received Pinput. Soil M1P for REI and REI-SD increased to a maximum of 55mg/kg while they received Pinput, and then gradually decreased after Pinput ceased. However, M1P for HEI increased steadily to a maximum of 145mg/kg by the end of the study with continued Pinput. Mehlich-1 P measured six years after the study still showed relatively high levels of P, a legacy effect of Pinput. The main factors influencing groundwater P concentration varied by seasons. During fall with frequent rainfall, the concentrations were influenced mainly by M1P and Pinput, and highlight a need for greater focus on Pinput management (vs. water management) during this season. However, during the dry period of spring, a greater focus on irrigation management is required since depth to water table and rainfall also become contributing factors. Three multivariate models (r(2)=0.67 to 0.93), for spring, fall, and annual periods, were developed for predicting groundwater P concentrations for a wide range of water and P inputs (0 to 191kg P2O5/ha of Pinput). The uniqueness of these models is that they use readily available hydrologic (rainfall and water table depth), management (Pinput), and soil (M1P) data commonly monitored by growers when managing water and nutrient inputs on agricultural landscapes. The development of similar models may not be necessary for other agro-ecosystems in similar regions since long-term data collected in these regions may be applied, with verification, to the models presented here. PMID:24981965

  16. Validation of bed-load transport measurements with time-sequenced bathymetric data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Advances in bathymetric data acquisition have made it possible to adopt a new, expedient method for measuring bed load transport in rivers. The method consists of comparing time sequenced bathymetric data sets and utilizing a simple mass conservation relation for bed load transport. Assuming a tri...

  17. The Indonesian's Road Transportations as the Contexts to Support Primary School Students Learning Number Operation

    ERIC Educational Resources Information Center

    Kairuddin; Darmawijoyo

    2011-01-01

    This paper highlights the Indonesian's road transportation contexts, namely, angkot, that used in learning and teaching of addition and subtraction in first grade and second grade MIN-2 Palembang. PMRI approach that adopt from RME [Realistic Mathematics Education] was used in this design research. From teaching experiment was founded that the…

  18. Pilot workload in the air transport environment : measurement, theory, and the influence of air traffic control

    E-print Network

    Katz, Jeffrey G.

    1980-01-01

    The operating environment of an air transport crew is characterized by multiple interrupting tasks, these tasks being composed of a mixture of purely physical control and purely mental planning processes. Measurement of ...

  19. Electrical transport measurements on honeycomb artificial spin ice.

    NASA Astrophysics Data System (ADS)

    Zeissler, Katharina; Chadha, Megha; Cohen, Lesley; Branford, Will; Functional Magnetism Group Team

    2014-03-01

    Artificial spin ice is a macroscopic playground for magnetically frustrated systems. We have previously shown that in a cobalt honeycomb artificial spin ice composed of 1 micron long nanowires there are unusual features in the magnetotransport below 50K. Here we explore the low temperature transport of equivalent artificial spin ice structures fabricated from permalloy. We discuss the extent to which the phenomenon is generic to the honeycomb artificial spin ice geometry and the effect of changing the constituent material on the onset temperature and the magnitude of the magnetotransport effect.

  20. Reliability as a measure of transportation system performance 

    E-print Network

    Jackson, Dena Delise

    2000-01-01

    This investigation involved a comparative analysis to assess the quantitative and qualitative characteristics of seven previously proposed methods of measuring travel time reliability. For each method, reliability was ...

  1. Molybdate transport in a chemically complex aquifer: Field measurements compared with solute-transport model predictions

    USGS Publications Warehouse

    Stollenwerk, K.G.

    1998-01-01

    A natural-gradient tracer test was conducted in an unconfined sand and gravel aquifer on Cape Cod, Massachusetts. Molybdate was included in the injectate to study the effects of variable groundwater chemistry on its aqueous distribution and to evaluate the reliability of laboratory experiments for identifying and quantifying reactions that control the transport of reactive solutes in groundwater. Transport of molybdate in this aquifer was controlled by adsorption. The amount adsorbed varied with aqueous chemistry that changed with depth as freshwater recharge mixed with a plume of sewage-contaminated groundwater. Molybdate adsorption was strongest near the water table where pH (5.7) and the concentration of the competing solutes phosphate (2.3 micromolar) and sulfate (86 micromolar) were low. Adsorption of molybdate decreased with depth as pH increased to 6.5, phosphate increased to 40 micromolar, and sulfate increased to 340 micromolar. A one-site diffuse-layer surface-complexation model and a two-site diffuse-layer surface-complexation model were used to simulate adsorption. Reactions and equilibrium constants for both models were determined in laboratory experiments and used in the reactive-transport model PHAST to simulate the two-dimensional transport of molybdate during the tracer test. No geochemical parameters were adjusted in the simulation to improve the fit between model and field data. Both models simulated the travel distance of the molybdate cloud to within 10% during the 2-year tracer test; however, the two-site diffuse-layer model more accurately simulated the molybdate concentration distribution within the cloud.

  2. Experimental measurements of the laminar separation bubble on an Eppler 387 airfoil at low Reynolds numbers

    NASA Technical Reports Server (NTRS)

    Cole, Gregory M.; Mueller, Thomas J.

    1990-01-01

    An experimental investigation was conducted to measure the flow velocity in the boundary layer of an Eppler 387 airfoil. In particular, the laminar separation bubble that this airfoil exhibits at low Reynolds numbers was the focus. Single component laser Doppler velocimetry data were obtained at a Reynolds number of 100,000 at an angle of attack of 2.0 degree. Static Pressure and flow visualization data for the Eppler 387 airfoil were also obtained. The difficulty in obtaining accurate experimental measurements at low Reynolds numbers is addressed. Laser Doppler velocimetry boundary layer data for the NACA 663-018 airfoil at a Reynolds number of 160,000 and angle of attack of 12 degree is also presented.

  3. Measured and simulated electron thermal transport in the Madisom symmetric torus reversed field pinch

    NASA Astrophysics Data System (ADS)

    Rodrigue Mbombo, Brice

    New high time resolution measurements of the evolution of the electron temperature profile through a sawtooth event in high current reversed-field pinch (RFP) discharges in the Madison Symmetric Torus (MST) have been made using the enhanced capabilities of the multipoint, multi-pulse Thomson scattering system. Using this and other data, the electron thermal diffusion chie determined and is found to vary by orders of magnitude over the course of the sawtooth cycle. This experimental data is compared directly to simulations run at experimentally relevant parameters. This includes zero beta, single fluid, nonlinear, resistive magnetohydrodynamic (MHD) simulations run with the aspect ratio, resistivity profile, and Lundquist number (S ˜ 4 x 106) of high current RFP discharges in MST. These simulations display MHD activity and sawtooth like behavior similar to that observed in the MST. This includes both the sawtooth period and the duration of the sawtooth crash. The radial shape of the magnetic mode amplitudes, scaled to match edge measurements made in MST, are then used to compute the expected level of thermal diffusion due to parallel losses along diffusing magnetic field lines, chiMD = upsilon?Dmag. The evolution of the Dmag profile was determined for over 20 sawteeth so that the ensemble averaged evolution could be compared to the sawtooth ensembled data from MST. The resulting comparison to the measured chi e shows that chiMD is larger than chi e at most times. However, if electrons are trapped in a magnetic well, they cannot carry energy along the diffusing magnetic field lines, reducing the thermal transport. Accounting for trapped particles brings chi MD to within uncertainty of chie in the mid radius at most times throughout the sawtooth cycle. In the core, the measured chie is greater than chi MD leading up to and including the sawtooth crash, suggesting other transport mechanisms are important at these times. Additionally, in a simulation including pressure evolution, a striking agreement is found between the temperature fluctuations seen in the simulation and those previously measured in MST. This work supported by the US DOE and NSF.

  4. A Reynolds Number Study of Wing Leading-Edge Effects on a Supersonic Transport Model at Mach 0.3

    NASA Technical Reports Server (NTRS)

    Williams, M. Susan; Owens, Lewis R., Jr.; Chu, Julio

    1999-01-01

    A representative supersonic transport design was tested in the National Transonic Facility (NTF) in its original configuration with small-radius leading-edge flaps and also with modified large-radius inboard leading-edge flaps. Aerodynamic data were obtained over a range of Reynolds numbers at a Mach number of 0.3 and angles of attack up to 16 deg. Increasing the radius of the inboard leading-edge flap delayed nose-up pitching moment to a higher lift coefficient. Deflecting the large-radius leading-edge flap produced an overall decrease in lift coefficient and delayed nose-up pitching moment to even higher angles of attack as compared with the undeflected large- radius leading-edge flap. At angles of attack corresponding to the maximum untrimmed lift-to-drag ratio, lift and drag coefficients decreased while lift-to-drag ratio increased with increasing Reynolds number. At an angle of attack of 13.5 deg., the pitching-moment coefficient was nearly constant with increasing Reynolds number for both the small-radius leading-edge flap and the deflected large-radius leading-edge flap. However, the pitching moment coefficient increased with increasing Reynolds number for the undeflected large-radius leading-edge flap above a chord Reynolds number of about 35 x 10 (exp 6).

  5. Measurement of plasma current dependent changes in impurity transport and comparison with nonlinear gyrokinetic simulation

    SciTech Connect

    Howard, N. T.; Greenwald, M.; White, A. E.; Reinke, M. L.; Ernst, D.; Podpaly, Y.; Mikkelsen, D. R.; Candy, J.

    2012-05-15

    Measured impurity transport coefficients are found to demonstrate a strong dependence on plasma current in the core of Alcator C-Mod. These measurements are compared directly with linear and nonlinear gyrokinetic simulation in an attempt to both qualitatively and quantitatively reproduce the measured impurity transport. Discharges constituting a scan of plasma current from 0.6 to 1.2 MA were performed during the 2010 run campaign. The impurity transport from these discharges was determined using a novel set of spectroscopic diagnostics available on Alcator C-Mod. This diagnostic suite allowed for the effective constraint of impurity transport coefficient profiles inside of r/a = 0.6. A decrease in the measured impurity diffusivity and inward convection is found with increased plasma current. Global, nonlinear gyrokinetic simulations were performed using the GYRO code [J. Candy and R. E. Waltz, J Comput. Phys. 186, 545 (2003)] for all discharges in the experimental scan and are found to reproduce the experimental trends, while demonstrating good quantitative agreement with measurement. A more comprehensive quantitative comparison was performed on the 0.8 MA discharge of the current scan which demonstrates that simultaneous agreement between experiment and simulation in both the impurity particle transport and ion heat transport channels is attainable within experimental uncertainties.

  6. Measurement of plasma current dependent changes in impurity transport and comparison with nonlinear gyrokinetic simulationa)

    NASA Astrophysics Data System (ADS)

    Howard, N. T.; Greenwald, M.; Mikkelsen, D. R.; White, A. E.; Reinke, M. L.; Ernst, D.; Podpaly, Y.; Candy, J.

    2012-05-01

    Measured impurity transport coefficients are found to demonstrate a strong dependence on plasma current in the core of Alcator C-Mod. These measurements are compared directly with linear and nonlinear gyrokinetic simulation in an attempt to both qualitatively and quantitatively reproduce the measured impurity transport. Discharges constituting a scan of plasma current from 0.6 to 1.2 MA were performed during the 2010 run campaign. The impurity transport from these discharges was determined using a novel set of spectroscopic diagnostics available on Alcator C-Mod. This diagnostic suite allowed for the effective constraint of impurity transport coefficient profiles inside of r/a = 0.6. A decrease in the measured impurity diffusivity and inward convection is found with increased plasma current. Global, nonlinear gyrokinetic simulations were performed using the GYRO code [J. Candy and R. E. Waltz, J Comput. Phys. 186, 545 (2003)] for all discharges in the experimental scan and are found to reproduce the experimental trends, while demonstrating good quantitative agreement with measurement. A more comprehensive quantitative comparison was performed on the 0.8 MA discharge of the current scan which demonstrates that simultaneous agreement between experiment and simulation in both the impurity particle transport and ion heat transport channels is attainable within experimental uncertainties.

  7. Tritium transport, influx, and helium ash measurements on TFTR during DT operation

    SciTech Connect

    Efthimion, P.C.; Johnson, L.C.; Skinner, C.H.

    1994-12-01

    The evolution of the tritium density profile is inferred from 14.1 MeV t(d,n){alpha} and 2.5 MeV d(d,n){sup 3}He neutron emissivity profiles measured in a deuterium neutral beam heated plasma into which a small amount of tritium gas has been puffed. For the first time, hydrogenic ion transport coefficients in the form of a diffusivity and convective velocity are determined. The particle diffusivities of tritium and {sup 4}He, and the deuterium thermal diffusivity are of similar magnitudes, and thus are consistent with theoretically calculated ExB drift transport. The first measurements of helium ash have been made using charge exchange recombination spectroscopy (CHERS). The measured radial ash profile shape is consistent with that predicted from simulations that include calculations of the central alpha ash source and thermal ash transport. This suggests that ash transport in the plasma core will not be a fundamental limiting factor in determining helium exhaust rates in a reactor. The authors also report the first spectroscopic measurements of tritium Balmer-alpha emission which provided a measure of tritium influx from the limiter. Tritium influx persists in discharges subsequent to tritium neutral beam injection, decaying with an initial decay of 7.5 discharges, and followed by a long term decay on the order of 400 discharges. Tritium transport, influx, and helium ash transport are important issues concerning profile control, retention, and ash removal for future reactors, like ITER.

  8. SLC Arc transport system: AG-magnet measurement and performance

    SciTech Connect

    Weng, W.T.; Anderson, M.; Byers, R.; Cobb, J.; Fischer, G.; Hamilton, V.

    1985-03-01

    This paper describes the design, construction, and operation of devices used to rapidly measure the mechanical and magnetic properties of some 950 Alternate gradient magnets used in the arc system of the Stanford Linear Collider. The problems of dealing with the measurement of the transverse dimensions to within minute (0.0001 in.) resolution of objects that are 8 ft long are discussed. Early results from the production runs of these magnets are presented. 7 refs., 6 figs.

  9. Reversing the weak measurement of an arbitrary field with finite photon number 

    E-print Network

    Sun, Qingqing; Al-Amri, M.; Zubairy, M. Suhail.

    2009-01-01

    the weak measurement of an arbitrary field with finite photon number Qingqing Sun,1,* M. Al-Amri,2 and M. Suhail Zubairy1 1Department of Physics and Institute of Quantum Studies, Texas A&M University, College Station, Texas 77843, USA 2The National...- ment ?1?, is only part of the story. There is another type of quantum measurement called weak measurement ?2?, in which the outcome is not precise or sharp but nevertheless reveals some information about the system. Since this weak measurement does...

  10. Velocity measurements of low Reynolds number tube flow using fiber-optic technology

    SciTech Connect

    Bianchi, J.C.

    1993-03-01

    In 1988 Nielsen started work to measure the spatial variability of the mass flux vector being transported in a porous medium. To measure the spatial variability of the mass flux vector, the spatial variability of its components(velocity, concentration) must be measured. Nielsen was successful in measuring the pore level concentration at many different pores and in verifying the assumption that a nonuniform concentration field exists within the mixing zone between two miscible fluids. However, Nielsen was unable to conduct the necessary pore level velocity measurements needed. Nielsen`s work is being continued and a probe is being developed that will measure both velocity and concentration components at pore level. The probe is essentially the same probe used to make the pore level concentration measurements with added capabilities needed to make the velocity measurements. This probe has several design variables, dealing primarily with the velocity component, that need further investigation. The research presented in this thesis investigates these parameters by performing experiments in a capillary tube. The tube is a controlled system where the velocity of the fluid can be determined from the volumetric flow rate using Poiseuille`s solution for viscous flow. Also, a statistically based relationship between the velocity measured with the probe and the velocity determined from the volumetric flow rate has been developed.

  11. Velocity measurements of low Reynolds number tube flow using fiber-optic technology

    SciTech Connect

    Bianchi, J.C.

    1993-03-01

    In 1988 Nielsen started work to measure the spatial variability of the mass flux vector being transported in a porous medium. To measure the spatial variability of the mass flux vector, the spatial variability of its components(velocity, concentration) must be measured. Nielsen was successful in measuring the pore level concentration at many different pores and in verifying the assumption that a nonuniform concentration field exists within the mixing zone between two miscible fluids. However, Nielsen was unable to conduct the necessary pore level velocity measurements needed. Nielsen's work is being continued and a probe is being developed that will measure both velocity and concentration components at pore level. The probe is essentially the same probe used to make the pore level concentration measurements with added capabilities needed to make the velocity measurements. This probe has several design variables, dealing primarily with the velocity component, that need further investigation. The research presented in this thesis investigates these parameters by performing experiments in a capillary tube. The tube is a controlled system where the velocity of the fluid can be determined from the volumetric flow rate using Poiseuille's solution for viscous flow. Also, a statistically based relationship between the velocity measured with the probe and the velocity determined from the volumetric flow rate has been developed.

  12. Backward-facing step measurements at low Reynolds number, Re(sub h)=5000

    NASA Technical Reports Server (NTRS)

    Jovic, Srba; Driver, David M.

    1994-01-01

    An experimental study of the flow over a backward-facing step at low Reynolds number was performed for the purpose of validating a direct numerical simulation (DNS) which was performed by the Stanford/NASA Center for Turbulence Research. Previous experimental data on back step flows were conducted at Reynolds numbers and/or expansion ratios which were significantly different from that of the DNS. The geometry of the experiment and the simulation were duplicated precisely, in an effort to perform a rigorous validation of the DNS. The Reynolds number used in the DNS was Re(sub h)=5100 based on step height, h. This was the maximum possible Reynolds number that could be economically simulated. The boundary layer thickness, d, was approximately 1.0 h in the simulation and the expansion ratio was 1.2. The Reynolds number based on the momentum thickness, Re(sub theta), upstream of the step was 610. All of these parameters were matched experimentally. Experimental results are presented in the form of tables, graphs and a floppy disk (for easy access to the data). An LDV instrument was used to measure mean velocity components and three Reynolds stresses components. In addition, surface pressure and skin friction coefficients were measured. LDV measurements were acquired in a measuring domain which included the recirculating flow region.

  13. Entanglement and Sensitivity in Precision Measurements with States of a Fluctuating Number of Particles

    SciTech Connect

    Hyllus, P.; Smerzi, A.; Pezze, L.

    2010-09-17

    The concepts of separability, entanglement, spin squeezing, and the Heisenberg limit are central in the theory of quantum-enhanced metrology. In the current literature, these are well established only in the case of linear interferometers operating with input quantum states of a known fixed number of particles. This manuscript generalizes these concepts and extends the quantum phase estimation theory by taking into account classical and quantum fluctuations of the particle number. Our analysis concerns most of the current experiments on precision measurements where the number of particles is known only on average.

  14. Continuous measurements of bedload transport rates in a small glacial river catchment in the summer season (Spitsbergen)

    NASA Astrophysics Data System (ADS)

    Kociuba, Waldemar; Janicki, Grzegorz

    2014-05-01

    The study on bedload transport was conducted on the gravel-bed Scott River catchment with a glacial alimentation regime, located in the NW part of the Wedel Jarlsberg Land (Spitsbergen) with subpolar climatic conditions. In the melt season of 2010, bedload transport rate was continuously monitored at 24-hour intervals by means of four River Bedload Trap devices aligned across the width of the channel. The maximum bedload transport rate varied strongly at portions of the cross section from 16 to 152 kg m- 1 d- 1 in cross-profile I (c-p I) and 4 to 125 kg m- 1 d- 1 in cross-profile II (c-p II). The maximum channel-mean bedload transport rate (qa) amounted to 54 kg m- 1 d- 1 (c-p I) and 35 kg m- 1 d- 1 (c-p II). Mean daily bedload discharge (Qb) was estimated at a level of 97 kg day- 1 (c-p I) and 35 kg m- 1 d- 1 (c-p II), and the total bedload yield was determined at approx. 4345 kg in the measurement period (2086 kg — c-p I; 2203 kg — c-p II from 13.07 to 10.08). The analysis of the relationship between channel-mean bedload transport rate and water velocity or shear stress revealed a significant value of the correlation coefficient (R2 = 0.6). Discharge and rate of bedload transport were dependent on the weather and number of days with flood discharge. Approx. 58% of the entire discharged bedload was transported during 3 violent ablation-precipitation floods. Bedload grain size distribution was right-skewed and showed moderate sorting.

  15. Measurements of Inertial Limit Alfven Wave Dispersion for Finite Perpendicular Wave Number

    SciTech Connect

    Kletzing, C. A.; Thuecks, D. J.; Skiff, F.; Bounds, S. R.; Vincena, S.

    2010-03-05

    Measurements of the dispersion relation for shear Alfven waves as a function of perpendicular wave number are reported for the inertial regime for which V{sub A}>V{sub Te}. The parallel phase velocity and damping are determined as k{sub perpendicular} varies and the measurements are compared to theoretical predictions. The comparison shows that the best agreement between theory and experiment is achieved for a fully complex plasma dispersion relation which includes the effects of electron collisions.

  16. Measurements of inertial limit Alfvén wave dispersion for finite perpendicular wave number.

    PubMed

    Kletzing, C A; Thuecks, D J; Skiff, F; Bounds, S R; Vincena, S

    2010-03-01

    Measurements of the dispersion relation for shear Alfvén waves as a function of perpendicular wave number are reported for the inertial regime for which V{A}>V{Te}. The parallel phase velocity and damping are determined as k{ perpendicular} varies and the measurements are compared to theoretical predictions. The comparison shows that the best agreement between theory and experiment is achieved for a fully complex plasma dispersion relation which includes the effects of electron collisions. PMID:20366989

  17. Direct measurement of sub-wavelength interference using thermal light and photon-number-resolved detection

    SciTech Connect

    Zhai, Yanhua E-mail: jfan@nist.gov; Fan, Jingyun E-mail: jfan@nist.gov; Migdall, Alan; Becerra, Francisco E.

    2014-09-08

    We examine thermal light diffracted through a double slit using photon-number-resolved detection to directly measure high-order spatial correlations, and we see sinusoidal modulations of those correlations. The fringe width can, in principal, be made arbitrarily small, and we have experimentally obtained fringe widths as small as 30?nm with 800?nm wavelength light. This extreme sub-wavelength resolution, along with this direct detection technique, offers potential for high precision measurement applications.

  18. Atmospheric effects on infrared measurements at ground level: Application to monitoring of transport infrastructures

    NASA Astrophysics Data System (ADS)

    Boucher, Vincent; Dumoulin, Jean

    2014-05-01

    Being able to perform easily non-invasive diagnostics for surveillance and monitoring of critical transport infrastructures is a major preoccupation of many technical offices. Among all the existing electromagnetic methods [1], long term thermal monitoring by uncooled infrared camera [2] is a promising technique due to its dissemination potential according to its low cost on the market. Nevertheless, Knowledge of environmental parameters during measurement in outdoor applications is required to carry out accurate measurement corrections induced by atmospheric effects at ground level. Particularly considering atmospheric effects and measurements in foggy conditions close as possible to those that can be encountered around transport infrastructures, both in visible and infrared spectra. In the present study, atmospheric effects are first addressed by using data base available in literature and modelling. Atmospheric attenuation by particles depends greatly of aerosols density, but when relative humidity increases, water vapor condenses onto the particulates suspended in the atmosphere. This condensed water increases the size of the aerosols and changes their composition and their effective refractive index. The resulting effect of the aerosols on the absorption and scattering of radiation will correspondingly be modified. In a first approach, we used aerosols size distributions derived from Shettle and Fenn [3] for urban area which could match some of experimental conditions encountered during trials on transport infrastructures opened to traffic. In order to calculate the influence of relative humidity on refractive index, the Hänel's model [4] could be used. The change in the particulate size is first related to relative humidity through dry particle radius, particle density and water activity. Once the wet aerosol particle size is found, the effective complex refractive index is the volume weighted average of the refractive indexes of the dry aerosol substance and the water. These changes in refractive indexes lead to the evolution of extinction coefficient Kext according to relative humidity. Using such models in very low visibility conditions leads to the following question: Up to which optical depth (i.e. tau=Kext.d) can we use a simple scattering model as Mie Theory? To show the effect of multiple scattering on previous transmission estimation, Monte-Carlo calculations have been performed. Calculations used a software dedicated to photometrical rendering of fog (PROF [5]). Up to an optical depth tau=1, simple and multiple scatterings differ of less than 2%. For tau >1 the simple scattering model is no more available to keep the error less than 10%. Finally, study of fog effect is proposed. Results obtained by numerical simulations but also by experiments carried out in a dedicated fog tunnel are presented and discussed. Perspectives about possible implementation on on site measurement systems are evocated. REFERENCES [1]Proto M. et al., , 2010. Transport infrastructure surveillance and monitoring by electromagnetic sensing: the ISTIMES project. Sensors, 10,10620-10639, doi: 10.3390/s101210620. [2]J. Dumoulin, A. Crinière, R. Averty ," Detection and thermal characterization of the inner structure of the "Musmeci" bridge deck by infrared thermography monitoring ",Journal of Geophysics and Engineering, Volume 10, Number 2, November 2013, IOP Science, doi:10.1088/1742-2132/10/6/064003. [3]Shettle. P. and Fenn R. W., "Models for the aerosols of the lower atmosphere and the effects of humidity variations on their optical properties", Air Force Geophysics Laboratory 79-0214, (1979). [4]30. Hänel, Gottfried, "The properties of atmospheric aerosol particles as functions of the relarive humidity at thermodynamic equilibrium with the surrounding moist air, in Advances in Geophysics, 73-188. Edited by H.E. Landsberg, and J. Van Mieghem, Academic Press, New York, 1976. [5]31. Dumont E., "Semi-Monte Carlo light tracing applied to the study of road visibility in fog", In Monte Ca

  19. MEASUREMENT OF LIGHT HYDROCARBONS AND OXIDANT TRANSPORT, HOUSTON AREA 1976

    EPA Science Inventory

    An extensive air pollutant monitoring program, including ground level and aerial sampling, was carried out in the Houston area during the month of July 1976. Measurements included ozone, oxides of nitrogen, PAN, methane, carbon monoxide, individual hydrocarbons (C2-C10), halocarb...

  20. Measuring urea persistence, distribution and transport on coastal plain soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The persistence and mobility of urea, an organic form of nitrogen present in animal manures and commercial fertilizers, has rarely been studied and measured, because it is assumed to undergo rapid hydrolysis to ammonia. However, preliminary studies have shown urea to exist in leachate and runoff sev...

  1. Effects of droplet interactions on droplet transport at intermediate Reynolds numbers

    NASA Technical Reports Server (NTRS)

    Shuen, J. S.

    1986-01-01

    Effects of droplet interactions on drag, evaporation, and combustion of a planar droplet array, oriented perpendicular to the approaching flow, are studied numerically. The three-dimensional Navier-Stokes equations, with variable thermophysical properties, are solved using finite-difference techniques. Parameters investigated include the droplet spacing, droplet Reynolds number, approaching stream oxygen concentration, and fuel type. Results are obtained for the Reynolds number range of 5 to 100, droplet spacing from 2 to 24 diameters, oxygen concentrations of 0.1 and 0.2, and methanol and n-butanol fuels. The calculations show that the gasification rates of interacting droplets decrease as the droplet spacings decrease. The reduction in gasification rates is significant only at small spacings and low Reynolds numbers. For the present array orientation, the effects of interactions on the gasification rates diminish rapidly for Reynolds numbers greater than 10 and spacings greater than 6 droplet diameters. The effects of adjacent droplets on drag are shown to be small.

  2. Effects of droplet interactions on droplet transport at intermediate Reynolds numbers

    NASA Technical Reports Server (NTRS)

    Shuen, Jian-Shun

    1987-01-01

    Effects of droplet interactions on drag, evaporation, and combustion of a planar droplet array, oriented perpendicular to the approaching flow, are studied numerically. The three-dimensional Navier-Stokes equations, with variable thermophysical properties, are solved using finite-difference techniques. Parameters investigated include the droplet spacing, droplet Reynolds number, approaching stream oxygen concentration, and fuel type. Results are obtained for the Reynolds number range of 5 to 100, droplet spacings from 2 to 24 diameters, oxygen concentrations of 0.1 and 0.2, and methanol and n-butanol fuels. The calculations show that the gasification rates of interacting droplets decrease as the droplet spacings decrease. The reduction in gasification rates is significant only at small spacings and low Reynolds numbers. For the present array orientation, the effects of interactions on the gasification rates diminish rapidly for Reynolds numbers greater than 10 and spacings greater than 6 droplet diameters. The effects of adjacent droplets on drag are shown to be small.

  3. PARALLEL MEASUREMENT AND MODELING OF TRANSPORT IN THE DARHT II BEAMLINE ON ETA II

    SciTech Connect

    Chambers, F W; Raymond, B A; Falabella, S; Lee, B S; Richardson, R A; Weir, J T; Davis, H A; Schultze, M E

    2005-05-31

    To successfully tune the DARHT II transport beamline requires the close coupling of a model of the beam transport and the measurement of the beam observables as the beam conditions and magnet settings are varied. For the ETA II experiment using the DARHT II beamline components this was achieved using the SUICIDE (Simple User Interface Connecting to an Integrated Data Environment) data analysis environment and the FITS (Fully Integrated Transport Simulation) model. The SUICIDE environment has direct access to the experimental beam transport data at acquisition and the FITS predictions of the transport for immediate comparison. The FITS model is coupled into the control system where it can read magnet current settings for real time modeling. We find this integrated coupling is essential for model verification and the successful development of a tuning aid for the efficient convergence on a useable tune. We show the real time comparisons of simulation and experiment and explore the successes and limitations of this close coupled approach.

  4. In situ measurements of colloid transport and retention using synchrotron X-ray fluorescence

    E-print Network

    In situ measurements of colloid transport and retention using synchrotron X-ray fluorescence David] The physics regarding the retention and mobilization of colloids in saturated and unsaturated conditions remains poorly understood, partially because of the inability to measure colloid concentrations in situ

  5. Tabulated pressure measurements on a large subsonic transport model airplane with high bypass ratio, powered, fan jet engines

    NASA Technical Reports Server (NTRS)

    Flechner, S. G.; Patterson, J. C., Jr.

    1972-01-01

    An experimental wind-tunnel investigation to determine the aerodynamic interference and the jet-wake interference associated with the wing, pylon, and high-bypass-ratio, powered, fan-jet model engines has been conducted on a typical high-wing logistics transport airplane configuration. Pressures were measured on the wing and pylons and on the surfaces of the engine fan cowl, turbine cowl, and plug. Combinations of wing, pylons, engines, and flow-through nacelles were tested, and the pressure coefficients are presented in tabular form. Tests were conducted at Mach numbers from 0.700 to 0.825 and angles of attack from -2 to 4 deg.

  6. Measurement of the copy number of the master quorum-sensing regulator of a bacterial cell

    E-print Network

    Ong, N. P.

    and fluctuations in gene expression in other systems. Considerable progress in understanding stochasticity in gene regulation has come from applying in vivo imaging techniques based on fluorescent reporter genes and fusionMeasurement of the copy number of the master quorum-sensing regulator of a bacterial cell Shu

  7. Measuring Middle Grades Teachers' Understanding of Rational Numbers with the Mixture Rasch Model

    ERIC Educational Resources Information Center

    Izsak, Andrew; Orrill, Chandra Hawley; Cohen, Allan S.; Brown, Rachael Eriksen

    2010-01-01

    We report the development of a multiple-choice instrument that measures the mathematical knowledge needed for teaching arithmetic with fractions, decimals, and proportions. In particular, the instrument emphasizes the knowledge needed to reason about such arithmetic when numbers are embedded in problem situations. We administered our instrument to…

  8. Compound pendant drop tensiometry for surface tension measurement at zero Bond number

    E-print Network

    Chan, Derek Y C

    Compound pendant drop tensiometry for surface tension measurement at zero Bond number Michael J, surface tension dominates and the drop does not deform. To address this problem, a complex experimental the interfacial tension between fluids is to quantify the pendant drop shape that is determined by gravity

  9. Volume 203, number 4 CHEMICAL PHYSICSLETTERS 26 February1993 Flame temperature measurement

    E-print Network

    Fayer, Michael D.

    Volume 203, number 4 CHEMICAL PHYSICSLETTERS 26 February1993 Flame temperature measurement using transient grating experiments were performed on a sodmm-seeded methane/air flame at very small fringe to that of velocity changing collisions. The form of the decay is determined by the Maxwell-Boltsmann velocity

  10. Measuring Physical Activity with Pedometers in Older Adults with Intellectual Disability: Reactivity and Number of Days

    ERIC Educational Resources Information Center

    Hilgenkamp, Thessa; Van Wijck, Ruud; Evenhuis, Heleen

    2012-01-01

    The minimum number of days of pedometer monitoring needed to estimate valid average weekly step counts and reactivity was investigated for older adults with intellectual disability. Participants (N = 268) with borderline to severe intellectual disability ages 50 years and older were instructed to wear a pedometer for 14 days. The outcome measure

  11. Estimation of Apollo Lunar Dust Transport using Optical Extinction Measurements

    NASA Astrophysics Data System (ADS)

    Lane, John E.; Metzger, Philip T.

    2015-04-01

    A technique to estimate mass erosion rate of surface soil during landing of the Apollo Lunar Module (LM) and total mass ejected due to the rocket plume interaction is proposed and tested. The erosion rate is proportional to the product of the second moment of the lofted particle size distribution N(D), and third moment of the normalized soil size distribution S(D), divided by the integral of S(D)?D2/v(D), where D is particle diameter and v(D) is the vertical component of particle velocity. The second moment of N(D) is estimated by optical extinction analysis of the Apollo cockpit video. Because of the similarity between mass erosion rate of soil as measured by optical extinction and rainfall rate as measured by radar reflectivity, traditional NWS radar/rainfall correlation methodology can be applied to the lunar soil case where various S(D) models are assumed corresponding to specific lunar sites.

  12. Estimation of Apollo lunar dust transport using optical extinction measurements

    E-print Network

    Lane, John E

    2015-01-01

    A technique to estimate mass erosion rate of surface soil during landing of the Apollo Lunar Module (LM) and total mass ejected due to the rocket plume interaction is proposed and tested. The erosion rate is proportional to the product of the second moment of the lofted particle size distribution N(D), and third moment of the normalized soil size distribution S(D), divided by the integral of S(D)D^2/v(D), where D is particle diameter and v(D) is the vertical component of particle velocity. The second moment of N(D) is estimated by optical extinction analysis of the Apollo cockpit video. Because of the similarity between mass erosion rate of soil as measured by optical extinction and rainfall rate as measured by radar reflectivity, traditional NWS radar/rainfall correlation methodology can be applied to the lunar soil case where various S(D) models are assumed corresponding to specific lunar sites.

  13. Absorption Measurements of 4s State Number density for a Microwave Argon Plasma

    NASA Astrophysics Data System (ADS)

    Li, Yunlong; Gordon, Matthew; Roe, Larry; Hassouni, Khaled

    1999-10-01

    Optical emission and continuum measurements have been performed to characterize microwave argon plasmas. A Wavemat (model MPDR-3135) microwave diamond deposition system was used to generate the argon plasma at 5 Torr with an argon flow rate of 300 sccm. In a previous study, three excited states number densities (4p, 5p, and 5d) were obtained from the emission measurements. These data were used to validate our zero-dimensional (with diffusion) Collisional-Radiative Model (CRM) by matching these three excited state number densities with the prediction from the CRM. An energy balance study showed that the energy absorbed by the argon plasma was far less than the reading from the power meters, also in agreement with our CRM predictions. To better characterize the plasma, we have recently measured the 4s population through absorption at 7635Å. The light source was a low-pressure AC argon lamp. To calculate the 4s number density, the lineshapes of the argon lamp and the argon plasma are needed. The lineshape of the argon lamp was taken from previous work which used a similar lamp. However, the plasma lineshape depends on the electron number density, the number densities of related excited states, the electron and gas temperatures, etc. For our microwave plasma system, these parameters cannot be measured directly. Therefore, the plasma lineshape was calculated based on the parameters predicted from the CRM. The 4s state number density calculted from this lineshape matches the predicted one from the CRM within the experimental uncertainty, further validating our model.

  14. Multi-bit quantum random number generation by measuring positions of arrival photons

    SciTech Connect

    Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun

    2014-10-15

    We report upon the realization of a novel multi-bit optical quantum random number generator by continuously measuring the arrival positions of photon emitted from a LED using MCP-based WSA photon counting imaging detector. A spatial encoding method is proposed to extract multi-bits random number from the position coordinates of each detected photon. The randomness of bits sequence relies on the intrinsic randomness of the quantum physical processes of photonic emission and subsequent photoelectric conversion. A prototype has been built and the random bit generation rate could reach 8 Mbit/s, with random bit generation efficiency of 16 bits per detected photon. FPGA implementation of Huffman coding is proposed to reduce the bias of raw extracted random bits. The random numbers passed all tests for physical random number generator.

  15. Loss-tolerant measurement-device-independent quantum random number generation

    E-print Network

    Zhu Cao; Hongyi Zhou; Xiongfeng Ma

    2015-10-30

    Quantum random number generators (QRNGs) output genuine random numbers based upon the uncertainty principle. A QRNG contains two parts in general --- a randomness source and a readout detector. How to remove detector imperfections has been one of the most important questions in practical randomness generation. We propose a simple solution, measurement-device-independent QRNG, which not only removes all detector side channels but is robust against losses. In contrast to previous fully device-independent QRNGs, our scheme does not require high detector efficiency or nonlocality tests. Simulations show that our protocol can be implemented efficiently with a practical coherent state laser and other standard optical components. The security analysis of our QRNG consists mainly of two parts: measurement tomography and randomness quantification, where several new techniques are developed to characterize the randomness associated with a positive-operator valued measure.

  16. Spectroscopic measurements of plasma temperatures and electron number density in a uranium hollow cathode discharge lamp

    NASA Astrophysics Data System (ADS)

    Shah, M. L.; Suri, B. M.; Gupta, G. P.

    2015-01-01

    The plasma parameters including neutral species temperature, atomic excitation temperature and electron number density in a see-through type, homemade uranium hollow cathode discharge lamp with neon as a buffer gas have been investigated using optical emission spectroscopic techniques. The neutral species temperature has been measured using the Doppler broadening of a neon atomic spectral line. The atomic excitation temperature has been measured using the Boltzmann plot method utilizing uranium atomic spectral lines. The electron number density has been determined from the Saha-Boltzmann equation utilizing uranium atomic and ionic spectral lines. To the best of our knowledge, all these three plasma parameters are simultaneously measured for the first time in a uranium hollow cathode discharge lamp.

  17. MEASUREMENTS AND COMPUTATIONS OF FUEL DROPLET TRANSPORT IN TURBULENT FLOWS

    SciTech Connect

    Joseph Katz and Omar Knio

    2007-01-10

    The objective of this project is to study the dynamics of fuel droplets in turbulent water flows. The results are essential for development of models capable of predicting the dispersion of slightly light/heavy droplets in isotropic turbulence. Since we presently do not have any experimental data on turbulent diffusion of droplets, existing mixing models have no physical foundations. Such fundamental knowledge is essential for understanding/modeling the environmental problems associated with water-fuel mixing, and/or industrial processes involving mixing of immiscible fluids. The project has had experimental and numerical components: 1. The experimental part of the project has had two components. The first involves measurements of the lift and drag forces acting on a droplet being entrained by a vortex. The experiments and data analysis associated with this phase are still in progress, and the facility, constructed specifically for this project is described in Section 3. In the second and main part, measurements of fuel droplet dispersion rates have been performed in a special facility with controlled isotropic turbulence. As discussed in detail in Section 2, quantifying and modeling the of droplet dispersion rate requires measurements of their three dimensional trajectories in turbulent flows. To obtain the required data, we have introduced a new technique - high-speed, digital Holographic Particle Image Velocimetry (HPIV). The technique, experimental setup and results are presented in Section 2. Further information is available in Gopalan et al. (2005, 2006). 2. The objectives of the numerical part are: (1) to develop a computational code that combines DNS of isotropic turbulence with Lagrangian tracking of particles based on integration of a dynamical equation of motion that accounts for pressure, added mass, lift and drag forces, (2) to perform extensive computations of both buoyant (bubbles) and slightly buoyant (droplets) particles in turbulence conditions relevant to the experiments, and (3) to explore whether the corresponding predictions can explain the experimentally-observed behavior of the rise and dispersion of oil droplets in isotropic turbulence. A brief summary of results is presented in Section 4.

  18. Resonant Acoustic Measurement of Vapor Phase Transport Phenomenon

    NASA Astrophysics Data System (ADS)

    Schuhmann, R. J.; Garrett, S. L.; Matson, J. V.

    2002-12-01

    A major impediment to accurate non steady-state diffusion measurements is the ability to accurately measure and track a rapidly changing gas concentration without disturbing the system. Non-destructive methods that do not interfere with system dynamics have been developed in the past. These methods, however, have tended to be cumbersome or inaccurate at low concentrations. A new experimental approach has been developed to measure gaseous diffusion in free air and through porous materials. The method combines the traditional non steady-state laboratory methodology with resonant acoustic gas analysis. A phase-locked-loop (PLL) resonance frequency tracker is combined with a thermally insulated copper resonator. A piston sealed with a metal bellows excites the fundamental standing wave resonance of the resonator. The PLL maintains a constant phase difference (typically 90§) between the accelerometer mounted on the piston and a microphone near the piston to track the resonance frequency in real time. A capillary or glass bead filled core is fitted into an o-ring sealed opening at the end of the resonator opposite the bellows. The rate at which the tracer gas is replaced by air within the resonator is controlled by the diffusion coefficient of the gas in free air through the capillary (DA) or by the effective diffusion coefficient of the gas through the core (De). The mean molecular weight of the gas mixture in the resonator is directly determined six times each minute from the ratio of the absolute temperature to the square of the fundamental acoustic resonance frequency. Average system stability (temperature divided by frequency squared) is better than 350 ppm. DA values for a 0.3-inch diameter capillary were in excellent agreement with published values. De values for porous media samples (0.5 mm glass beads) of four different lengths (1 through 4 inches) using three different tracer gases (He, CH4, Kr) will be reported. Comments will be offered regarding tracer gas selection and device orientation and their effect on experimental results. [Work supported by the Office of Naval Research.

  19. Electrophysiological Motor Unit Number Estimation (MUNE) Measuring Compound Muscle Action Potential (CMAP) in Mouse Hindlimb Muscles.

    PubMed

    Arnold, W David; Sheth, Kajri A; Wier, Christopher G; Kissel, John T; Burghes, Arthur H; Kolb, Stephen J

    2015-01-01

    Compound muscle action potential (CMAP) and motor unit number estimation (MUNE) are electrophysiological techniques that can be used to monitor the functional status of a motor unit pool in vivo. These measures can provide insight into the normal development and degeneration of the neuromuscular system. These measures have clear translational potential because they are routinely applied in diagnostic and clinical human studies. We present electrophysiological techniques similar to those employed in humans to allow recordings of mouse sciatic nerve function. The CMAP response represents the electrophysiological output from a muscle or group of muscles following supramaximal stimulation of a peripheral nerve. MUNE is an electrophysiological technique that is based on modifications of the CMAP response. MUNE is a calculated value that represents the estimated number of motor neurons or axons (motor control input) supplying the muscle or group of muscles being tested. We present methods for recording CMAP responses from the proximal leg muscles using surface recording electrodes following the stimulation of the sciatic nerve in mice. An incremental MUNE technique is described using submaximal stimuli to determine the average single motor unit potential (SMUP) size. MUNE is calculated by dividing the CMAP amplitude (peak-to-peak) by the SMUP amplitude (peak-to-peak). These electrophysiological techniques allow repeated measures in both neonatal and adult mice in such a manner that facilitates rapid analysis and data collection while reducing the number of animals required for experimental testing. Furthermore, these measures are similar to those recorded in human studies allowing more direct comparisons. PMID:26436455

  20. Multi-component measurements in high Reynolds number turbulent boundary layers

    NASA Astrophysics Data System (ADS)

    Baidya, Rio; Philip, Jimmy; Hutchins, Nicholas; Monty, Jason; Marusic, Ivan

    2012-11-01

    Measurements, with highly resolved spectra are obtained in high Reynolds number (Re?) turbulent boundary layers using sub-miniature cross-wires. The probe consists of 2 . 5 ? m diameter platinum wires welded across the sharpened stainless steel prong tips, contained in a volume of 0 . 4 × 0 . 4 × 0 . 2 mm3. Velocity profiles are measured at various stream-wise positions with nominally matched unit Reynolds number (U? / ?). In this manner the same probe geometry affords approximately matched viscous-scaled sensor length (l+) and sensor spacing (?s+) across the entire range of Re? , such that Reynolds number trends can be observed free of spatial resolution effects. The probes have matched measurement volumes of approximately 14 × 14 × 7 (+/- 10 %) viscous length scales across all Re? . The prong is inclined at 10° to the horizontal, permitting measurements close to the wall while also minimising blockage effects. The prongs are fabricated to account for this inclination, ensuring that the sensing elements remain parallel to the wall at the desired prong orientation. The resulting highly resolved multi-component velocity statistics up to Re? = 10 , 000 and their associated trends against Re? will be presented.

  1. Time domain reflectometry measurements of solute transport across a soil layer boundary

    SciTech Connect

    Nissen, H.H.; Moldrup, P.; Kachanoski, R.G.

    2000-02-01

    The mechanisms governing solute transport through layered soil are not fully understood. Solute transport at, above, and beyond the interface between two soil layers during quasi-steady-state soil water movement was investigated using time domain reflectometry (TDR). A 0.26-m sandy loam layer was packed on top of a 1.35-m fine sand layer in a soil column. Soil water content ({theta}) and bulk soil electrical conductivity (EC{sub b}) were measured by 50 horizontal and 2 vertical TDR probes. A new TDR calibration method that gives a detailed relationship between apparent relative dielectric permittivity (K{sub s}) and {theta} was applied. Two replicate solute transport experiments were conducted adding a conservative tracer (CCl) to the surface as a short pulse. The convective lognormal transfer function model (CLT) was fitted to the TDR-measured time integral-normalized resident concentration breakthrough curves (BTCs). The BTCs and the average solute-transport velocities showed preferential flow occurred across the layer boundary. A nonlinear decrease in TDR-measured {theta} in the upper soil toward the soil layer boundary suggests the existence of a 0.10-m zone where water is confined towards fingered flow, creating lateral variations in the area-averaged water flux above the layer boundary. A comparison of the time integral-normalized flux concentration measured by vertical and horizontal TDR probes at the layer boundary also indicates a nonuniform solute transport. The solute dispersivity remained constant in the upper soil layer, but increased nonlinearly (and further down, linearly) with depth in the lower layer, implying convective-dispersive solute transport in the upper soil, a transition zone just below the boundary, and stochastic-convective solute transport in the remaining part of the lower soil.

  2. Spin transport and precession in graphene measured by nonlocal and three-terminal methods

    SciTech Connect

    Dankert, André Kamalakar, Mutta Venkata; Bergsten, Johan; Dash, Saroj P.

    2014-05-12

    We investigate the spin transport and precession in graphene by using the Hanle effect in nonlocal and three-terminal measurement geometries. Identical spin lifetimes, spin diffusion lengths, and spin polarizations are observed in graphene devices for both techniques over a wide range of temperatures. The magnitude of the spin signals is well explained by spin transport models. These observations rules out any signal enhancements or additional scattering mechanisms at the interfaces for both geometries. This validates the applicability of both the measurement methods for graphene based spintronics devices and their reliable extractions of spin parameters.

  3. Measurement of the transport spin polarization of FeV using point-contact Andreev reflection

    SciTech Connect

    Bailey, William; Osofsky, Mike; Bussman, Konrad; Parker, David S; Cheng, L

    2013-01-01

    The Fe1 xVx alloy system exhibits the lowest known Gilbert relaxation rate of any ferromagnetic metal or binary alloy with G1 435MHz at x1 427% V. Low relaxation rates are of particular interest in modern spin electronic applications involving spin torque. The transport spin polarization of a series of sputtered epitaxial Fe1 xVx samples was measured using point contact Andreev reflection. Values of the transport spin polarization agree well with those measured for pure Fe and are independent of composition. The results indicate that the substitution of up to 50% of V for Fe does not reduce the spin polarization in the alloy.

  4. Measurements of the production and transport of helium ash on the TFTR Tokamak

    SciTech Connect

    Synakowski, E.J.; Bell, R.E.; Budny, R.V.

    1995-03-01

    Helium ash production and transport have been measured in TFTR deuterium-tritium plasmas using charge-exchange recombination spectroscopy. The helium ash confinement time, including recycling effects, is 6--10 times the energy confinement time and is compatible with sustained ignition in a reactor. The ash confinement time is dominated by edge pumping rates rather than core transport. The measured evolution of the local thermal ash density agrees with modeling, indicating that alpha particle slowing-down calculations used in the modeling are reasonable.

  5. Comparison of Thermoelectric Transport Measurement Techniques Using n-type PbSe

    NASA Astrophysics Data System (ADS)

    Wang, Heng; Fedorov, Mikhail I.; Shabaldin, Aleksander A.; Konstantinov, Piotr P.; Snyder, G. Jeffrey

    2015-06-01

    We compare high-temperature thermoelectric transport measurements at two different institutes using different setups. The material studied is n-type PbSe doped with Cl. The measurements at the Ioffe Institute used a steady-state design which allowed all three properties to be measured simultaneously from bar-shaped samples. Those at Caltech have used Van der Pauw geometry for resistivity, an oscillation method for the Seebeck coefficient, and a laser flash technique for thermal conductivity. The results for each individual property show differences around 10% in some cases, while the evaluation of overall zT for the three samples with different doping levels is mostly below 10%. The steady-state method at the Ioffe Institute was able to measure thermal conductivity at high temperature as accurately as the laser flash method. In general, great caution is needed for any setup in order to accurately measure high-temperature transport properties and hence zT.

  6. Measurements in a Braided River chute and lobe: 1. Flow pattern, sediment transport, and channel change

    NASA Astrophysics Data System (ADS)

    Ferguson, R. I.; Ashmore, P. E.; Ashworth, P. J.; Paola, C.; Prestegaard, K. L.

    1992-07-01

    This paper and its companion (Ashworth et al., this issue) discuss measurements of channel change and associated flow and sediment transport processes in a representative chute-and-bar reach within a proglacial gravel-bed river, the Sunwapta River in the Canadian Rockies. During a week in which water discharge through the reach increased then decreased, a sediment wave passed into and partly along the reach. At first the chute aggraded, then sediment was eroded from the chute and deposited in a prograding lobe to one side of the original bar head between two distributaries. Measurements of velocity, shear stress, and gravel transport rate revealed day-to-day changes in the divergent pattern of flow and sediment transport. The off-center location of the lobe reflected an initial asymmetry in the pattern of flow and sediment transport, but as the lobe grew, the flow and transport gradually switched away to the other distributary. Width-averaged bed load transport rates do not agree well with average rates inferred from bar head deposition or from volumes and spatial patterns of scour and fill; the indirect estimates are considered more reliable than those based on direct sampling for necessarily brief durations. By the end of the study the new lobe had almost accreted onto the original bar head, supporting the idea that most braid bars are of compound origin. Temporal and spatial patterns in grain size distributions of the bed, bed load, and deposited sediment are discussed in the companion paper.

  7. [Tractive force measurement in bone transport--an in vivo investigation in humans].

    PubMed

    Baumgart, R; Kuhn, V; Hinterwimmer, S; Krammer, M; Mutschler, W

    2004-09-01

    Bone transport applying the principle of distraction osteogenesis makes it possible to reconstruct long bone defects caused by trauma or resection of bone tumors. The method employing a central cable, developed in Munich, is especially suitable for such applications. The main bone fragments are stabilized by an external fixateur, and bone transport is effected with a single central cable fixed to the tip of the segment, and driven by an external, programmable motor. In 15 patients the tractive forces during the entire bone transport were measured with a strain gauge incorporated within the cable. On the basis of the force profiles characteristics normal bone transport (forces between 150-250 N) can be distinguished from a critical transport (forces > 250 N) with the risk of premature consolidation. There is some evidence that at a very high level of force, just before premature consolidation a very effective form of bone transport with good bone neoformation can be achieved. Transport systems employing a central cable allow this special form of distraction osteogenesis, since there is continuous force monitoring, and there is the option of employing the traction force as a control factor in a loop. PMID:15493133

  8. Detailed noise measurements on the SR-7A propeller: Tone behavior with helical tip Mach number

    NASA Technical Reports Server (NTRS)

    Dittmar, James H.; Hall, David G.

    1991-01-01

    Detailed noise measurements were taken on the SR-7A propeller to investigate the behavior of the noise with helical tip Mach number and then to level off as Mach number was increased further. This behavior was further investigated by obtaining detailed pressure-time histories of data. The pressure-time histories indicate that a portion of the primary pressure pulse is progressively cancelled by a secondary pulse which results in the noise leveling off as the helical tip Mach number is increased. This second pulse appears to originate on the same blade as the primary pulse and is in some way connected to the blade itself. This leaves open the possibility of redesigning the blade to improve the cancellation; thereby, the propeller noise is reduced.

  9. Measurement of bedload transport in sand-bed rivers: a look at two indirect sampling methods

    USGS Publications Warehouse

    Holmes, Robert R., Jr.

    2010-01-01

    Sand-bed rivers present unique challenges to accurate measurement of the bedload transport rate using the traditional direct sampling methods of direct traps (for example the Helley-Smith bedload sampler). The two major issues are: 1) over sampling of sand transport caused by “mining” of sand due to the flow disturbance induced by the presence of the sampler and 2) clogging of the mesh bag with sand particles reducing the hydraulic efficiency of the sampler. Indirect measurement methods hold promise in that unlike direct methods, no transport-altering flow disturbance near the bed occurs. The bedform velocimetry method utilizes a measure of the bedform geometry and the speed of bedform translation to estimate the bedload transport through mass balance. The bedform velocimetry method is readily applied for the estimation of bedload transport in large sand-bed rivers so long as prominent bedforms are present and the streamflow discharge is steady for long enough to provide sufficient bedform translation between the successive bathymetric data sets. Bedform velocimetry in small sandbed rivers is often problematic due to rapid variation within the hydrograph. The bottom-track bias feature of the acoustic Doppler current profiler (ADCP) has been utilized to accurately estimate the virtual velocities of sand-bed rivers. Coupling measurement of the virtual velocity with an accurate determination of the active depth of the streambed sediment movement is another method to measure bedload transport, which will be termed the “virtual velocity” method. Much research remains to develop methods and determine accuracy of the virtual velocity method in small sand-bed rivers.

  10. Photon-number statistics of twin beams: Self-consistent measurement, reconstruction, and properties

    SciTech Connect

    Pe?ina, Jan Jr.; Haderka, Ond?ej; Michálek, Václav

    2014-12-04

    A method for the determination of photon-number statistics of twin beams using the joint signal-idler photocount statistics obtained by an iCCD camera is described. It also provides absolute quantum detection efficiency of the camera. Using the measured photocount statistics, quasi-distributions of integrated intensities are obtained. They attain negative values occurring in characteristic strips an a consequence of pairing of photons in twin beams.

  11. Source of transport site asymmetry in the band 3 anion exchange protein determined by NMR measurements of external Cl- affinity.

    PubMed

    Liu, D; Kennedy, S D; Knauf, P A

    1996-12-01

    Flux measurements indicate that a far greater number of unloaded band 3 anion transport sites face the cytoplasm than face the external medium, but the reason for this striking asymmetry has remained obscure. To resolve this question, we have measured the apparent Cl- affinity of the transport site of human red blood cell band 3 protein under various conditions by analyzing the 35Cl NMR free induction decay (FID). The [Cl-] that half-saturates the transport sites with [Cli] = [Clo] (K1/2) in RBC membranes (ghosts) is 46 +/- 5 mM at 0 degree C, while the Ko1/2 (for half-saturation with [Clo] at constant [Cli]) of intact cells is 3.2 +/- 2.1 mM. When cells were pretreated with EM, an inhibitor of band 3 anion exchange that does not prevent Cl- binding to the external transport site, K1/2 and Ko1/2 are 41 +/- 14 and 46 +/- 12 mM, respectively. The EM-induced increase in Ko1/2 with little change in K1/2 can be most simply interpreted as meaning that EM abolishes the effects of the translocation rate constants on Ko1/2 so that Ko1/2 and K1/2 of EM-treated cells now both reflect the true dissociation constant for binding of Cl- to the external transport site, Ko. The fact that Ko for a slowly transported anion, iodide, is nearly the same in EM-treated as in control cells indicates that EM does not significantly affect Ko for chloride. Our results indicate that the true dissociation constants for Cl- at the inside and outside are very similar but that the rate constant for inward translocation is much larger than that for outward translocation. For this reason, both unloaded and Cl-loaded transport sites are asymmetrically oriented toward the inside, and Ko1/2 (in untreated cells) is much lower than Ko. PMID:8952471

  12. Bipolar carrier transport in tris(8-hydroxy-quinolinato) aluminum observed by impedance spectroscopy measurements

    NASA Astrophysics Data System (ADS)

    Ishihara, Shingo; Hase, Hiroyuki; Okachi, Takayuki; Naito, Hiroyoshi

    2011-08-01

    We studied bipolar carrier transport in tris(8-hydroxy-quinolinato) aluminum (Alq3) thin films using impedance spectroscopy (IS). Two transit times were observed in the impedance spectra of the Alq3 double-injection diodes. The mobilities determined from the transit times are in good agreement with the electron and the hole mobilities in Alq3 measured by IS using single injection diodes and by the time-of-flight transient photocurrent technique. The bipolar carrier transport observed in Alq3 shows that the carrier recombination of Alq3 is weak on the basis of the simulation [M. Schmeits, J. Appl. Phys. 101, 084508 (2007)]. Simultaneous measurements of electron and hole mobilities are useful in the study of charge-carrier transport in active layers in organic light-emitting diodes and organic solar cells.

  13. The generation of 68 Gbps quantum random number by measuring laser phase fluctuations

    SciTech Connect

    Nie, You-Qi; Liu, Yang; Zhang, Jun Pan, Jian-Wei; Huang, Leilei; Payne, Frank

    2015-06-15

    The speed of a quantum random number generator is essential for practical applications, such as high-speed quantum key distribution systems. Here, we push the speed of a quantum random number generator to 68 Gbps by operating a laser around its threshold level. To achieve the rate, not only high-speed photodetector and high sampling rate are needed but also a very stable interferometer is required. A practical interferometer with active feedback instead of common temperature control is developed to meet the requirement of stability. Phase fluctuations of the laser are measured by the interferometer with a photodetector and then digitalized to raw random numbers with a rate of 80 Gbps. The min-entropy of the raw data is evaluated by modeling the system and is used to quantify the quantum randomness of the raw data. The bias of the raw data caused by other signals, such as classical and detection noises, can be removed by Toeplitz-matrix hashing randomness extraction. The final random numbers can pass through the standard randomness tests. Our demonstration shows that high-speed quantum random number generators are ready for practical usage.

  14. The generation of 68 Gbps quantum random number by measuring laser phase fluctuations

    NASA Astrophysics Data System (ADS)

    Nie, You-Qi; Huang, Leilei; Liu, Yang; Payne, Frank; Zhang, Jun; Pan, Jian-Wei

    2015-06-01

    The speed of a quantum random number generator is essential for practical applications, such as high-speed quantum key distribution systems. Here, we push the speed of a quantum random number generator to 68 Gbps by operating a laser around its threshold level. To achieve the rate, not only high-speed photodetector and high sampling rate are needed but also a very stable interferometer is required. A practical interferometer with active feedback instead of common temperature control is developed to meet the requirement of stability. Phase fluctuations of the laser are measured by the interferometer with a photodetector and then digitalized to raw random numbers with a rate of 80 Gbps. The min-entropy of the raw data is evaluated by modeling the system and is used to quantify the quantum randomness of the raw data. The bias of the raw data caused by other signals, such as classical and detection noises, can be removed by Toeplitz-matrix hashing randomness extraction. The final random numbers can pass through the standard randomness tests. Our demonstration shows that high-speed quantum random number generators are ready for practical usage.

  15. The generation of 68 Gbps quantum random number by measuring laser phase fluctuations.

    PubMed

    Nie, You-Qi; Huang, Leilei; Liu, Yang; Payne, Frank; Zhang, Jun; Pan, Jian-Wei

    2015-06-01

    The speed of a quantum random number generator is essential for practical applications, such as high-speed quantum key distribution systems. Here, we push the speed of a quantum random number generator to 68 Gbps by operating a laser around its threshold level. To achieve the rate, not only high-speed photodetector and high sampling rate are needed but also a very stable interferometer is required. A practical interferometer with active feedback instead of common temperature control is developed to meet the requirement of stability. Phase fluctuations of the laser are measured by the interferometer with a photodetector and then digitalized to raw random numbers with a rate of 80 Gbps. The min-entropy of the raw data is evaluated by modeling the system and is used to quantify the quantum randomness of the raw data. The bias of the raw data caused by other signals, such as classical and detection noises, can be removed by Toeplitz-matrix hashing randomness extraction. The final random numbers can pass through the standard randomness tests. Our demonstration shows that high-speed quantum random number generators are ready for practical usage. PMID:26133826

  16. Manipulating atoms in an optical lattice: Fractional fermion number and its optical quantum measurement

    E-print Network

    J. Ruostekoski; J. Javanainen; G. V. Dunne

    2007-09-13

    We provide a detailed analysis of our previously proposed scheme [Phys. Rev. Lett. 88, 180401, (2002)] to engineer the profile of the hopping amplitudes for atomic gases in a 1D optical lattice so that the particle number becomes fractional. We consider a constructed system of a dilute two-species gas of fermionic atoms where the two components are coupled via a coherent electromagnetic field with a topologically nontrivial phase profile. We show both analytically and numerically how the resulting atomic Hamiltonian in a prepared dimerized optical lattice with a defect in the pattern of alternating hopping amplitudes exhibits a fractional fermion number. In particular, in the low-energy limit we demonstrate the equivalence of the atomic Hamiltonian to a relativistic Dirac Hamiltonian describing fractionalization in quantum field theory. Expanding on our earlier argument [Phys. Rev. Lett. 91, 150404 (2003)] we show how the fractional eigenvalues of the particle number operator can be detected via light scattering. In particular, we show how scattering of far-off resonant light can convey information about the counting statistics of the atoms in an optical lattice, including state-selective atom density profiles and atom number fluctuations. Optical detection could provide a truly quantum mechanical measurement of the particle number fractionalization in a dilute atomic gas.

  17. Optimized imaging polarimeter for measuring polarization properties of hyper number aperture lithography tools

    NASA Astrophysics Data System (ADS)

    Li, Lei; Li, Yanqiu; Chi, Quan; Liu, Ke; Zhang, Xuebing; Li, Jianhui

    2014-09-01

    An imaging polarimeter is developed for measuring polarization properties of hyper number aperture (NA) lithography tools, which can be represented by stokes entrance-pupil, stokes exit-pupil and mueller pupil of projection optics. This imaging polarimeter is optimized from the following three aspects. Firstly, a new method is proposed to measure stokes entrance-pupil of projection optics. It employs a rotating-waveplate and a fixed-polarizer as polarization state analyzer (PSA). Compared to the method proposed by Nomura, the number of measurements is reduced from 16 to 4 times. Additionally, the large incident angle in the mask plane leads to unacceptable retardation error of conventional waveplate, which terribly influent the measurement accuracy of the imaging polarimeter. Therefore, the imaging polarimeter can be optimized by employing a wide-view-angle (WVA) waveplate composed of quartz and sapphire plates. An example of 632.8nm WVA ?/4 waveplate is designed based on least square algorithm, which is firstly introduced to calculate the thicknesses of four crystal plates. Simulation result shows that the retardation error is less than 0.3° for incident angle within 20°. Thirdly, the WVA waveplate is successfully fabricated and its retardation is calibrated by senarmont method. Measurement data is contributed to eliminate the uncertainty of retardation and thus improves the performance of the imaging polarimeter. Because of the lack of lithography equipment, the imaging polarimeter is preliminarily tested in the visible optical system with a He-Ne laser. Stokes entrance-pupil, stokes exit-pupil and mueller pupil of projection optics are all measured with quite enough measurement repeatability.

  18. Large-scale laboratory measurements of sheet flow sediment transport in the swash zone

    NASA Astrophysics Data System (ADS)

    Lanckriet, T. M.; Puleo, J. A.; Foster, D. L.

    2013-12-01

    Existing sediment transport models show poor predictive quality when applied to the swash zone, indicating that the underlying processes of swash zone sediment transport are not yet fully understood. The recognition that more detailed measurements are needed to improve understanding of swash-zone processes has led to several recent innovations in swash-zone measurement techniques. One of these innovative measurement techniques, the Conductivity Concentration Profiler (CCP), was developed to address the issue of near-bed (sheet flow) sediment transport, which is believed to be an important part of the overall swash-zone sediment transport. Measurements of sheet flow processes in the swash zone from the Barrier Dynamics Experiment (Bardex-II) are presented. The aim of this study was to investigate the dynamics of a coastal barrier system and develop an increased understanding of cross-shore sediment transport processes in the nearshore zone of sandy beaches. A 70-m long, near-prototype scale sandy barrier was constructed in a large wave flume facility and equipped with over 200 sensors to measure hydrodynamics and sediment processes ranging from the shoaling-wave zone to the back barrier. CCP sensors were deployed at three locations in the swash zone as part of the ';swash and berm dynamics' work package. Onshore-directed pressure gradients, observed during the initial stages of uprush, enhanced sediment mobilization. The combination of near-bed sediment mobilization due to pressure gradients (known as plug flow) and shear stress (sheet flow) is examined. Sediment load in the sheet flow layer is also compared to suspended load and total load measured using an array of optical backscatter sensors. The sheet flow layer thickness is compared to hydrodynamic forcing such as bed shear stress and the effect of groundwater exchange.

  19. Deformation of an elastic body in low Reynolds number transport: Relevance to biofilm deformation and streamer formation

    E-print Network

    Gupta, Nikhil; Mitra, Sushanta K; Kumar, Aloke

    2015-01-01

    In this paper, we obtain analytical results for shear stress distributions inside an elastic body placed in a low Reynolds number transport. The problem definition is inspired by a recent experimental study (Valiei et al., Lab Chip, 2012, 12, 5133-5137) that reports the flow-triggered deformation of bacterial biofilms, formed on cylindrical rigid microposts, into long filamentous structures known as streamers. In our analysis, we consider an elastic body of finite thickness (forming a rim) placed over a rigid cylinder, i.e., we mimic the biofilm structure in the experiment. We consider Oseen flow solution to describe the low Reynolds transport past this cylindrical elastic structure. The stress and strain distributions inside the elastic structure are found to be functions of position, Poisson ratio, initial thickness of the elastic rim and the ratio of the flow-driven shear stress to the shear modulus of the elastic body. More importantly, these analyses, which can be deemed as one of the first formal analys...

  20. Measurement and modeling of ultrafast carrier dynamics and transport in germanium/silicon-

    E-print Network

    Miller, David A. B.

    Measurement and modeling of ultrafast carrier dynamics and transport in germanium/silicon- germanium quantum wells Stephanie A. Claussen,1,3,* Emel Tasyurek,1,3 Jonathan E. Roth, 1,2 and David A. B. S. Harris, and D. A. B. Miller, Optical modulator on silicon employing germanium quantum wells, Opt

  1. Measurements of Combined Axial Mass and Heat Transport in He II.

    ERIC Educational Resources Information Center

    Johnson, Warren W.; Jones, Michael C.

    An experiment was performed that allowed measurements of both axial mass and heat transport of He-II (the superfluid phase of helium 4) in a long tube. The apparatus allowed the pressure difference and the temperature difference across the flow tube to each be independently adjusted, and the resulting steady-state values of net fluid velocity and…

  2. Measurement of voltage-dependent electronic transport across amine-linked single-molecular-wire junctions

    E-print Network

    Measurement of voltage-dependent electronic transport across amine-linked single-molecular- wire. 2009 Nanotechnology 20 434009 (http://iopscience.iop.org/0957-4484/20/43/434009) Download details: IP Search Collections Journals About Contact us My IOPscience #12;IOP PUBLISHING NANOTECHNOLOGY

  3. UARS/MLS Cloud Ice Measurements: Implications for H2O Transport near the Tropopause

    E-print Network

    Sherwood, Steven

    UARS/MLS Cloud Ice Measurements: Implications for H2O Transport near the Tropopause D. L. WU AND W) retrievals are made near the tropopause using estimated size distributions from in situ convective studies. Introduction Clouds near the tropical tropopause layer (TTL) play an important role in the water budget

  4. DIRECT MEASUREMENT OF FAST AXONAL ORGANELLE TRANSPORT IN THE SCIATIC NERVE OF RATS TREATED WITH ACRYLAMIDE

    EPA Science Inventory

    The effects of acrylamide on fast axonal transport have been measured primarily using the indirect methods of isotope or enzyme accumulation. e report the first direct evaluation of the effects of sub-chronic acrylamide dosing (150, 300 or 500 mg/kg total dose) on the fast axonal...

  5. Oxygen transport in zeolite Y measured by quenching of encapsulated tris(bipyridyl)ruthenium

    E-print Network

    Dutta, Prabir K.

    Oxygen transport in zeolite Y measured by quenching of encapsulated tris(bipyridyl)ruthenium Abstract This study deals with emission quenching of zeolite encapsulated trisbipyridyl ruthenium (II) (Ru the migration of O2 within zeolites using the emis- sion quenching of zeolite encapsulated ruthenium

  6. Development of high speed continuous transport critical current measurement system for long piece of HTS conductor

    NASA Astrophysics Data System (ADS)

    Kim, Seokho; Park, Minwon; Yu, In-Keun; Kim, Gyeong-Hun; Ha, Hong-Su; Sim, Kideok; Oh, Sang-Soo; Moon, Seung-Hyun

    2013-01-01

    In case of long pieces of HTS conductor, their critical current measurement is an important process for the conductor manufacturer and the customer, however, it is very time consuming process. Conventional critical current measurement is carried out by ‘four probe method’, which increase the transport current and measure the voltage between the fixed voltage taps. Therefore, it consists of conductor moving and measuring process. To speed up the measuring process, longer distance between voltage taps is required. In this case, the measured critical current is averaged and small defects, which can be very crucial for thermal stability, cannot be found. Therefore, the limitation of the voltage tap length should be carefully decided considering the cooling environment. Another non-contact or indirect method is to measure the screening effect of magnetic field and converting the field signal to the critical current, which is called as hall probe method. This process is known as a very efficient way to find local defects and estimate the distribution of the critical current, however, it contains inevitable error and noise because it should measure the small magnetic field signals. This paper describes a new critical current measurement system, which have similar hardware structure of conventional ‘four probe method’. However, it is much faster than other systems using fast feedback control of the transport current while the conductor is continuously moving with high speed. The measured results are compared with the conventional method and hall probe method.

  7. Statistical Measurements of Contact Conditions of 478 Transport-airplane Landings During Routine Daytime Operations

    NASA Technical Reports Server (NTRS)

    Silsby, Norman S

    1955-01-01

    Statistical measurements of contact conditions have been obtained, by means of a special photographic technique, of 478 landings of present-day transport airplanes made during routine daylight operations in clear air at the Washington National Airport. From the measurements, sinking speeds, rolling velocities, bank angles, and horizontal speeds at the instant before contact have been evaluated and a limited statistical analysis of the results has been made and is reported in this report.

  8. Measurement of carrier transport and recombination parameter in heavily doped silicon

    NASA Technical Reports Server (NTRS)

    Swanson, Richard M.

    1986-01-01

    The minority carrier transport and recombination parameters in heavily doped bulk silicon were measured. Both Si:P and Si:B with bulk dopings from 10 to the 17th and 10 to the 20th power/cu cm were studied. It is shown that three parameters characterize transport in bulk heavily doped Si: the minority carrier lifetime tau, the minority carrier mobility mu, and the equilibrium minority carrier density of n sub 0 and p sub 0 (in p-type and n-type Si respectively.) However, dc current-voltage measurements can never measure all three of these parameters, and some ac or time-transient experiment is required to obtain the values of these parameters as a function of dopant density. Using both dc electrical measurements on bipolar transitors with heavily doped base regions and transients optical measurements on heavily doped bulk and epitaxially grown samples, lifetime, mobility, and bandgap narrowing were measured as a function of both p and n type dopant densities. Best fits of minority carrier mobility, bandgap narrowing and lifetime as a function of doping density (in the heavily doped range) were constructed to allow accurate modeling of minority carrier transport in heavily doped Si.

  9. Characterization of the transport properties of channel delta-doped structures by light-modulated Shubnikov-de Haas measurements

    NASA Technical Reports Server (NTRS)

    Mena, R. A.; Schacham, S. E.; Haugland, E. J.; Alterovitz, S. A.; Young, P. G.; Bibyk, S. B.; Ringel, S. A.

    1995-01-01

    The transport properties of channel delta-doped quantum well structures were characterized by conventional Hall effect and light-modulated Shubnikov-de Haas (SdH) effect measurements. The large number of carriers that become available due to the delta-doping of the channel, leads to an apparent degeneracy in the well. As a result of this degeneracy, the carrier mobility remains constant as a function of temperature from 300 K down to 1.4 K. The large amount of impurity scattering, associated with the overlap of the charge carriers and the dopants, resulted in low carrier mobilities and restricted the observation of the oscillatory magneto-resistance used to characterize the two-dimensional electron gas (2DEG) by conventional SdH measurements. By light-modulating the carriers, we were able to observe the SdH oscillation at low magnetic fields, below 1.4 tesla, and derive a value for the quantum scattering time. Our results for the ratio of the transport and quantum scattering times are lower than those previously measured for similar structures using much higher magnetic fields.

  10. Mobile lidar system for measurement of water vapor mixing ratio and ozone number density

    NASA Technical Reports Server (NTRS)

    Whiteman, D.

    1988-01-01

    The Water Vapor Lidar was modified and extended to make differential absorption measurements of ozone. Water vapor measurements make use of a weak molecular scattering process known as Raman scattering. It is characterized by a shift in wavelength of the scattered beam of light relative to the incident one. Some of the energy of the incident photon is converted to vibrational or rotational energy within the molecule leaving the scattered photon shifted to a slightly longer wavelength. When performing water vapor measurements, profiles are acquired of water vapor mixing ratio from near the ground to beyond 7 km every 2 minutes. By forming a color composite image of the individual profiles, the spatial and temporal evolution of water vapor is visible with vertical resolution of 75 to 150m and temporal resolution of 2 minutes. The ozone lidar is intended for use as a cross calibration facility for other stationary ozone lidar systems. The ozone measurement employs the technique known as differential absorption. The backscattered laser radiation from two different wavelengths is measured. Successful measurements of 308 nm returns were made from 80 km with an averaging period of 6 hours. Using these data and a standard atmosphere density curve, an ozone number density profile was made which agrees very well with the standard ozone curve between 20 and 40 km.

  11. Gliders Measure Western Boundary Current Transport from the South Pacific to the Equator

    NASA Astrophysics Data System (ADS)

    Davis, R. E.; Kessler, W. S.; Sherman, J. T.

    2011-12-01

    Since 2007, the Consortium on the Ocean's Role in Climate (CORC) has used repeated glider transects across the southern Solomon Sea to measure the previously nearly unsampled mass and heat transport from the South Pacific to the equatorial zone. Mean transport is dominated by the New Guinea Coastal Undercurrent (NGCUC). This low-latitude western boundary current is a major element of the shallow meridional overturning circulation, returning water from the subtropical South Pacific to the Equatorial Undercurrent (EUC) where it upwells. We find the mean NGCUC to be a jet less than 100 km wide, centered near 300 m depth, with equatorward velocities reaching 35 cm/s and salinity anomalies on isopycnals up to 0.05. Weaker poleward flow is found near the surface in the eastern basin. Equatorward transport above 700 m is typically 20 Sv, but nearly vanished during two La Niñas and reached 25 Sv during an El Niño. Within these events the seasonal cycle cannot yet be defined. Transport variability is strongest outside the boundary current and appears to consist of two independently moving layers with a boundary near 250 m. ENSO variability is predominantly in the upper layer. The relation of Solomon Sea mass and heat transport with ENSO indicators will be discussed The ability to initiate and maintain measurements that support such quantitative analyses with a small effort in a remote site far from research institutions demonstrates that gliders can be a productive part of the global ocean observing system.

  12. Simple and Versatile Molecular Method of Copy-Number Measurement Using Cloned Competitors

    PubMed Central

    Kim, Hyun-Kyoung; Hwang, Hai-Li; Park, Seong-Yeol; Lee, Kwang Man; Park, Won Cheol; Kim, Han-Seong; Um, Tae-Hyun; Hong, Young Jun; Lee, Jin Kyung; Joo, Sun-Young; Seoh, Ju-Young; Song, Yeong-Wook; Kim, Soo-Youl; Kim, Yong-Nyun; Hong, Kyeong-Man

    2013-01-01

    Variations and alterations of copy numbers (CNVs and CNAs) carry disease susceptibility and drug responsiveness implications. Although there are many molecular methods to measure copy numbers, sensitivity, reproducibility, cost, and time issues remain. In the present study, we were able to solve those problems utilizing our modified real competitive PCR method with cloned competitors (mrcPCR). First, the mrcPCR for ERBB2 copy number was established, and the results were comparable to current standard methods but with a shorter assay time and a lower cost. Second, the mrcPCR assays for 24 drug-target genes were established, and the results in a panel of NCI-60 cells were comparable to those from real-time PCR and microarray. Third, the mrcPCR results for FCGR3A and the FCGR3B CNVs were comparable to those by the paralog ratio test (PRT), but without PRT's limitations. These results suggest that mrcPCR is comparable to the currently available standard or the most sensitive methods. In addition, mrcPCR would be invaluable for measurement of CNVs in genes with variants of similar structures, because combination of the other methods is not necessary, along with its other advantages such as short assay time, small sample amount requirement, and applicability to all sequences and genes. PMID:23936009

  13. Using RFID and accelerometer-embedded tracers to measure probabilities of bed load transport, step lengths, and rest times in a mountain stream

    NASA Astrophysics Data System (ADS)

    Olinde, Lindsay; Johnson, Joel P. L.

    2015-09-01

    We present new measurements of bed load tracer transport in a mountain stream over several snowmelt seasons. Cumulative displacements were measured using passive tracers, which consisted of gravel and cobbles embedded with radio frequency identification tags. The timing of bed load motion during 11 transporting events was quantified with active tracers, i.e., accelerometer-embedded cobbles. Probabilities of cobble transport increased with discharge above a threshold, and exhibited slight to moderate hysteresis during snowmelt hydrographs. Dividing cumulative displacements by the number of movements recorded by each active tracer constrained average step lengths. Average step lengths increased with discharge, and distributions of average step lengths and cumulative displacements were thin tailed. Distributions of rest times followed heavy-tailed power law scaling. Rest time scaling varied somewhat with discharge and with the degree to which tracers were incorporated into the streambed. The combination of thin-tailed displacement distributions and heavy-tailed rest time distributions predict superdiffusive dispersion.

  14. Controlling and measuring quantum transport of heat in trapped-ion crystals

    E-print Network

    A. Bermudez; M. Bruderer; M. B. Plenio

    2013-07-23

    Measuring heat flow through nanoscale systems poses formidable practical difficulties as there is no `ampere meter' for heat. We propose to overcome this problem by realizing heat transport through a chain of trapped ions. Laser cooling the chain edges to different temperatures induces a current of local vibrations (vibrons). We show how to efficiently control and measure this current, including fluctuations, by coupling vibrons to internal ion states. This demonstrates that ion crystals provide a suitable platform for studying quantum transport, e.g., through thermal analogues of quantum wires and quantum dots. Notably, ion crystals may give access to measurements of the elusive large fluctuations of bosonic currents and the onset of Fourier's law. These results are supported by numerical simulations for a realistic implementation with specific ions and system parameters.

  15. Apparatus for measurements of transport properties of thin films under sulfur atmosphere at moderate temperatures

    NASA Astrophysics Data System (ADS)

    Clamagirand, J. M.; Ares, J. R.; Diaz-Chao, P.; Pascual, A.; Ferrer, I. J.; Sánchez, C.

    2015-04-01

    An experimental system able to simultaneously measure the electrical resistance and the thermopower of metallic and semiconducting thin films (with thicknesses from ~nm to ~µm) under sulfur atmosphere from room temperature up to 400?°C and total pressures >0.5-1?mbar is designed and implemented. Calibration tests of the system were performed with palladium foils and films as well as p-type and n-type sulfide semiconducting films: iron disulfide and palladium monosulfide. Uncertainties of measured thermopower and resistance values are less than 10% and 5%, respectively. To check the capability of the system under sulfur atmosphere, in situ measurements of transport properties during sulfuration of palladium films were carried out. During the process, sulfur partial pressure and film temperature are accurately controlled. Apparatus may be used to determine the evolution of transport properties of different metal sulfides during their formation/decomposition processes, opening new pathways to investigate the thermoelectric properties of more complex thin film sulfides.

  16. Improvement of Pulping Uniformity by Measurement of Single Fiber Kappa Number

    SciTech Connect

    Richard R. Gustafson; James B. Callis

    2001-11-20

    A method to measure the kappa of single fibers by staining with a fluorescent dye, Acridine Orange (AO), has been developed. This method is now applied to develop and automated flow-through instrument that permits routine kappa analysis on thousands of images of AO stained fibers to give the fiber kappa number distribution of a pulp sample in a few minutes. The design and operation of the instrument are similar to that of a flow cytometer but with the addition of extensive fiber imaging capability. Fluorescence measurements in the flow-through instrument are found to be consistent with those made with fluorescence microscope provided the signal processing in the flow-thou instrument is handled propertly. The kappa distributions of pulps that were analyzed by means of a density gradient column are compared to those measured with the flow-through instrument with good results. The kappa distributions of various laboratory pulps and commercial pulps have been measured. It has been found that all pulps are non-uniform but that ommercial pulps generally have broader kappa distributions thatn their laboratory counterparts. The effects of different pulping methods and chip pretreatments on pulp uniformity are discussed in the report. Finally, the application of flow-through fluorescence technology to other single fiber measurements are presented.

  17. Tree measures and the number of segregating sites in time-structured population samples

    PubMed Central

    Forsberg, Roald; Drummond, Alexei J; Hein, Jotun

    2005-01-01

    Background Time-structured genetic samples are a valuable source of information in population genetics because they provide several correlated observations of the underlying evolutionary processes. In this paper we study basic properties of the genetic variation in time-structured samples as reflected in the genealogies relating individuals and the number of segregating sites observed. Our emphasis is on "measurably evolving populations" i.e. populations from which it is possible to obtain time-structured samples that span a significant interval of evolutionary time. Results We use results from the coalescent process to derive properties of time-structured samples. In the first section we extend existing results to attain measures on coalescent trees relating time-structured samples. These include the expected time to a most recent common ancestor, the expected total branch length and the expected length of branches subtending only ancient individuals. The effect of different sampling schemes on the latter measure is studied. In the second section we study the special case where the full sample consists of a group of contemporary extant samples and a group of contemporary ancient samples. As regards this case, we present results and applications concerning the probability distribution of the number of segregating sites where a mutation is unique to the ancient individuals and the number of segregating sites where a mutation is shared between ancient and extant individuals. Conclusion The methodology and results presented here is of use to the design and interpretation of ancient DNA experiments. Furthermore, the results may be useful in further development of statistical tests of e.g. population dynamics and selection, which include temporal information. PMID:15960847

  18. Particle number emissions of motor traffic derived from street canyon measurements in a Central European city

    NASA Astrophysics Data System (ADS)

    Klose, S.; Birmili, W.; Voigtländer, J.; Tuch, T.; Wehner, B.; Wiedensohler, A.; Ketzel, M.

    2009-02-01

    A biennial dataset of ambient particle number size distributions (diameter range 4-800 nm) collected in urban air in Leipzig, Germany, was analysed with respect to the influence of traffic emissions. Size distributions were sampled continuously in 2005 and 2006 inside a street canyon trafficked by ca. 10 000 motor vehicles per day, and at a background reference site distant at 1.5 km. Auto-correlation analysis showed that the impact of fresh traffic emissions could be seen most intensely below particle sizes of 60 nm. The traffic-induced concentration increment at roadside was estimated by subtracting the urban background values from the street canyon measurement. To describe the variable dispersion conditions inside the street canyon, micro-meteorological dilution factors were calculated using the Operational Street Pollution Model (OSPM), driven by above-roof wind speed and wind direction observations. The roadside increment concentrations, dilution factor, and real-time traffic counts were used to calculate vehicle emission factors (aerosol source rates) that are representative of the prevailing driving conditions, i.e. stop-and-go traffic including episodes of fluent traffic flow at speeds up to 40 km h-1. The size spectrum of traffic-derived particles was essentially bimodal - with mode diameters around 12 and 100 nm, while statistical analysis suggested that the emitted number concentration varied with time of day, wind direction, particle size and fleet properties. Significantly, the particle number emissions depended on ambient temperature, ranging between 4.8 (±1.8) and 7.8 (±2.9).1014 p. veh-1 km-1 in summer and winter, respectively. A separation of vehicle types according to vehicle length suggested that lorry-like vehicles emit about 80 times more particle number than passenger car-like vehicles. Using nitrogen oxide (NOx) measurements, specific total particle number emissions of 338 p. (pg NOx)-1 were inferred. The calculated traffic emission factors, considering particle number and size, are anticipated to provide useful input for future air quality and particle exposure modelling in densely populated urban areas.

  19. The Experimental Measurement of Aerodynamic Heating About Complex Shapes at Supersonic Mach Numbers

    NASA Technical Reports Server (NTRS)

    Neumann, Richard D.; Freeman, Delma C.

    2011-01-01

    In 2008 a wind tunnel test program was implemented to update the experimental data available for predicting protuberance heating at supersonic Mach numbers. For this test the Langley Unitary Wind Tunnel was also used. The significant differences for this current test were the advances in the state-of-the-art in model design, fabrication techniques, instrumentation and data acquisition capabilities. This current paper provides a focused discussion of the results of an in depth analysis of unique measurements of recovery temperature obtained during the test.

  20. Measurements Required to Understand the Lunar Dust Environment and Transport Mechanism

    NASA Technical Reports Server (NTRS)

    Spann, James F., Jr.; Abbas, Mian

    2006-01-01

    Going back to the lunar surface offers an opportunity to understand the dust environment and associated transport mechanisms. This talk will explore what measurements are required to understand and characterize the dust-plasma environment in which robotic and human activities will be conducted. The understanding gained with the measurements can be used to make informed decisions on engineering solutions and follow-on investigations. Particular focus will be placed on required measurements of the size, spatial and charge distribution of the suspended lunar regolith.

  1. PHYSICAL REVIEW B 90, 214429 (2014) Transport measurements of the spin-wave parameters of thin Mn films

    E-print Network

    Muttalib, Khandker

    2014-01-01

    PHYSICAL REVIEW B 90, 214429 (2014) Transport measurements of the spin-wave parameters of thin Mn; published 17 December 2014) Temperature-dependent transport measurements on ultrathin antiferromagnetic Mn technologies but are also expected to play an important role in future developments [1]. Understanding

  2. Measurement of black carbon at Syowa station, Antarctica: seasonal variation, transport processes and pathways

    NASA Astrophysics Data System (ADS)

    Hara, K.; Osada, K.; Yabuki, M.; Hayashi, M.; Yamanouchi, T.; Shiobara, M.; Wada, M.

    2008-05-01

    Measurement of black carbon (BC) was carried out at Syowa station Antarctica (69° S, 39° E) from February 2004 until January 2007. The BC concentration at Syowa ranged from below detection to 176 ng m-3 during the measurements. Higher BC concentrations were observed mostly under strong wind (blizzard) conditions due to the approach of a cyclone and blocking event. The BC-rich air masses traveled from the lower troposphere of the Atlantic and Indian Oceans to Syowa (Antarctic coast). During the summer (November-February), the BC concentration showed a diurnal variation together with surface wind speed and increased in the katabatic wind from the Antarctic continent. Considering the low BC source strength in the Antarctic continent, the higher BC concentration in the continental air (katabatic wind) might be caused by long range transport of BC via the free troposphere from mid- and low- latitudes. The seasonal variation of BC at Syowa had a maximum in August, while at the other coastal stations (Halley, Neumayer, and Ferraz) and the continental station (Amundsen-Scott), the maximum occurred in October. This difference may result from different transport pathways and scavenging of BC by precipitation during the transport from the source regions. During the austral summer, long-range transport of BC via the free troposphere is likely to make an important contribution to the ambient BC concentration. The BC transport flux indicated that BC injection into the Antarctic region strongly depended on the frequency of storm (blizzard) conditions. The seasonal variation of BC transport flux increased by 290 mg m-2 month-1 in winter-spring when blizzards frequently occurred, whereas the flux decreased to lower than 50 mg m-2 month-1 in the summer with infrequent blizzards.

  3. PUBLISHED ONLINE: 8 DECEMBER 2014 | DOI: 10.1038/NPHYS3171 Measuring the Chern number of Hofstadter bands

    E-print Network

    Loss, Daniel

    of a charged particle in a magnetic field. The artificial flux is thus produced by engineering complex deflection of an atomic cloud in response to an optical gradient to measure the Chern number of artificially.99(5). This first Chern-number measurement in a non-electronic system is facilitated by an all-optical artificial

  4. The effective number density of galaxies for weak lensing measurements in the LSST project

    NASA Astrophysics Data System (ADS)

    Chang, C.; Jarvis, M.; Jain, B.; Kahn, S. M.; Kirkby, D.; Connolly, A.; Krughoff, S.; Peng, E.-H.; Peterson, J. R.

    2013-09-01

    Future weak lensing surveys potentially hold the highest statistical power for constraining cosmological parameters compared to other cosmological probes. The statistical power of a weak lensing survey is determined by the sky coverage, the inverse of the noise in shear measurements and the galaxy number density. The combination of the latter two factors is often expressed in terms of neff - the `effective number density of galaxies used for weak lensing measurements'. In this work, we estimate neff for the Large Synoptic Survey Telescope (LSST) project, the most powerful ground-based lensing survey planned for the next two decades. We investigate how the following factors affect the resulting neff of the survey with detailed simulations: (1) survey time, (2) shear measurement algorithm, (3) algorithm for combining multiple exposures, (4) inclusion of data from multiple filter bands, (5) redshift distribution of the galaxies and (6) masking and blending. For the first time, we quantify in a general weak lensing analysis pipeline the sensitivity of neff to the above factors. We find that with current weak lensing algorithms, expected distributions of observing parameters, and all lensing data (r and i band, covering 18 000 degree2 of sky) for LSST, neff ? 37 arcmin-2 before considering blending and masking, neff ? 31 arcmin-2 when rejecting seriously blended galaxies and neff ? 26 arcmin-2 when considering an additional 15 per cent loss of galaxies due to masking. With future improvements in weak lensing algorithms, these values could be expected to increase by up to 20 per cent. Throughout the paper, we also stress the ways in which neff depends on our ability to understand and control systematic effects in the measurements.

  5. Duration of High Flow Releases from Dams: Insights from Recent Bedload Transport Measurements

    NASA Astrophysics Data System (ADS)

    Hales, G.; Pryor, C.; McBain, S.

    2006-12-01

    Assessments to prescribe flow releases from dams have historically focused on baseflow releases, typically to satisfy fish habitat, recreation, or other biological objectives. High flow releases that exceed fluvial geomorphic thresholds are being increasingly prescribed to satisfy restoration objectives on regulated rivers. High flow releases must consider flow magnitude, duration, frequency, timing, and rate of change. The role of peak flow release magnitude in accomplishing restoration objectives is much better understood than is the role of peak flow release duration. Is a flow release of 10,000 cubic feet per second (cfs) for ten days twice as "effective" as a 10,000 cfs release for five days? Duration has been a more challenging prescriptive parameter because of: (1) high sensitivity to overall water volume, and (2) uncertainty in how it satisfies fluvial geomorphic and ecological objectives (e.g., bedload transport, channel migration, fish rearing, and riparian vegetation). Using bedload transport rate as an index of fluvial geomorphic work, bedload transport was repeatedly measured on two California streams over prolonged steady high flow releases to assess the role of duration. Preliminary results suggest that bedload transport rates dropped significantly after two to three days of prolonged steady high flow release. While bedload transport is only one of several potential objectives addressed by high flow duration, application of these results to high flow management suggests that short duration, high magnitude flow releases are more efficient at satisfying some fluvial geomorphic objectives than longer duration, moderate magnitude flow releases.

  6. Measurement of cross-field heat transport in a nonneutral plasma

    NASA Astrophysics Data System (ADS)

    Hollmann, E. M.; Anderegg, F.; Driscoll, C. F.

    1999-01-01

    The cross-magnetic field heat transport in a Mg+ plasma confined in a Penning-Malmberg trap is found to be dominated by novel long-range collisions. The measurement uses two lasers: a strong cooling beam creates a controlled temperature gradient in the plasma and a weak probe beam measures the ion temperature evolution. The temperature gradient drives a heat flux which dominates the measured temperature evolution, with corrections due to small external heating terms. Classical theory of collisional heat conductivity considers only ion-ion collisions with collisionality ? and impact parameter ?transport, giving ?L?(1/2)??D2. Initial measurements taken for a plasma with temperature T?.02 eV and density n?5×107 cm-3 at B=4 T show enhanced heat transport consistent with thermal diffusion dominated by these long-range collisions.

  7. Benchmarking Space Radiation Transport Codes Using Measured LET Spectra from the Crater Instrument on LRO

    NASA Astrophysics Data System (ADS)

    Townsend, L. W.; Porter, J.; Spence, H. E.; Golightly, M. J.; Smith, S. S.; Schwadron, N.; Kasper, J. C.; Case, A. W.; Blake, J. B.; Mazur, J. E.; Looper, M. D.; Zeitlin, C. J.

    2014-12-01

    The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument on the Lunar Reconnaissance Orbiter (LRO) spacecraft measures the energy depositions by solar and galactic cosmic radiations in its silicon detectors. These energy depositions are converted to linear energy transfer (LET) spectra, which can contribute to benchmarking space radiation transport codes and also used to estimate doses for the Lunar environment. In this work the Monte Carlo transport code HETC-HEDS (High Energy Transport Code - Human Exploration and Development in Space) and the deterministic NASA space radiation transport code HZETRN2010 are used to estimate LET and dose contributions from the incident primary ions and their charged secondaries produced in nuclear collisions within the components of the CRaTER instrument. Comparisons of the calculated LET spectra with measurements of LET from the CRaTER instrument are made and clearly show the importance of including corrections to the calculated average energy deposition spectra in the silicon detectors using a Vavilov distribution function.

  8. Functional regression analysis using an F test for longitudinal data with large numbers of repeated measures.

    PubMed

    Yang, Xiaowei; Shen, Qing; Xu, Hongquan; Shoptaw, Steven

    2007-03-30

    Longitudinal data sets from certain fields of biomedical research often consist of several variables repeatedly measured on each subject yielding a large number of observations. This characteristic complicates the use of traditional longitudinal modelling strategies, which were primarily developed for studies with a relatively small number of repeated measures per subject. An innovative way to model such 'wide' data is to apply functional regression analysis, an emerging statistical approach in which observations of the same subject are viewed as a sample from a functional space. Shen and Faraway introduced an F test for linear models with functional responses. This paper illustrates how to apply this F test and functional regression analysis to the setting of longitudinal data. A smoking cessation study for methadone-maintained tobacco smokers is analysed for demonstration. In estimating the treatment effects, the functional regression analysis provides meaningful clinical interpretations, and the functional F test provides consistent results supported by a mixed-effects linear regression model. A simulation study is also conducted under the condition of the smoking data to investigate the statistical power for the F test, Wilks' likelihood ratio test, and the linear mixed-effects model using AIC. PMID:16817228

  9. Investigation of Aerosol Surface Area Estimation from Number and Mass Concentration Measurements: Particle Density Effect

    PubMed Central

    Ku, Bon Ki; Evans, Douglas E.

    2015-01-01

    For nanoparticles with nonspherical morphologies, e.g., open agglomerates or fibrous particles, it is expected that the actual density of agglomerates may be significantly different from the bulk material density. It is further expected that using the material density may upset the relationship between surface area and mass when a method for estimating aerosol surface area from number and mass concentrations (referred to as “Maynard’s estimation method”) is used. Therefore, it is necessary to quantitatively investigate how much the Maynard’s estimation method depends on particle morphology and density. In this study, aerosol surface area estimated from number and mass concentration measurements was evaluated and compared with values from two reference methods: a method proposed by Lall and Friedlander for agglomerates and a mobility based method for compact nonspherical particles using well-defined polydisperse aerosols with known particle densities. Polydisperse silver aerosol particles were generated by an aerosol generation facility. Generated aerosols had a range of morphologies, count median diameters (CMD) between 25 and 50 nm, and geometric standard deviations (GSD) between 1.5 and 1.8. The surface area estimates from number and mass concentration measurements correlated well with the two reference values when gravimetric mass was used. The aerosol surface area estimates from the Maynard’s estimation method were comparable to the reference method for all particle morphologies within the surface area ratios of 3.31 and 0.19 for assumed GSDs 1.5 and 1.8, respectively, when the bulk material density of silver was used. The difference between the Maynard’s estimation method and surface area measured by the reference method for fractal-like agglomerates decreased from 79% to 23% when the measured effective particle density was used, while the difference for nearly spherical particles decreased from 30% to 24%. The results indicate that the use of particle density of agglomerates improves the accuracy of the Maynard’s estimation method and that an effective density should be taken into account, when known, when estimating aerosol surface area of nonspherical aerosol such as open agglomerates and fibrous particles. PMID:26526560

  10. Theoretical and measured aeolian sand transport on a barrier island, Louisiana, USA

    USGS Publications Warehouse

    Dingler, J.R.; Hsu, S.A.; Reiss, T.E.

    1992-01-01

    Over the past 100 yr, the Isles Dernieres, a low lying barrier island chain along the coast of central Louisiana, has undergone more than 1km of northward beach face retreat within the loss of 70% of its surface area. The erosion results from a long term relative sea level rise coupled with day to day wind and wave action that ultimately favours erosion over deposition. The theoretical estimate of 1.28 m3 m-1 for the rate of sand transport by the northerly wind compares well with the measured backshore erosion rate of 1.26m3 m-1, which was determined by comparing beach profiles from the start and end of the period of northerly winds. The theoretical estimate of 0.04m3 m-1 for the rate of sand transport by the southerly wind, however, is notably less than the measured rate of 0.45m3 m-1. -from Authors

  11. Inelastic quantum transport in a ladder model: Measurements of DNA conduction and comparison to theory

    E-print Network

    R. Gutierrez; S. Mohapatra; H. Cohen; D. Porath; G. Cuniberti

    2006-07-14

    We investigate quantum transport characteristics of a ladder model, which effectively mimics the topology of a double-stranded DNA molecule. We consider the interaction of tunneling charges with a selected internal vibrational degree of freedom and discuss its influence on the structure of the current-voltage characteristics. Further, molecule-electrode contact effects are shown to dramatically affect the orders of magnitude of the current. Recent electrical transport measurements on suspended DNA oligomers with a complex base-pair sequence, revealing strikingly high currents, are also presented and used as a reference point for the theoretical modeling. A semi-quantitative description of the measured I-V curves is achieved, suggesting that the coupling to vibrational excitations plays an important role in DNA conduction.

  12. Simultaneous Raman and electrical transport measurements of disordered graphene in situ in ultra-high vacuum

    NASA Astrophysics Data System (ADS)

    Tosado, Jacob; Ballarotto, Vince; Cullen, William G.; Fuhrer, Michael S.

    2012-02-01

    Resonant Raman scattering in graphene gives unique information about disorder, as the D peak is observed only in the presence of disorder which produces intervalley scattering of the electrons. The nature of disorder in graphene prepared by various techniques and on various substrates of the subject of significant research, with significant attention being paid to scattering by charged impurities; resonant scatterers due to vacancies, chemisorbed impurities, etc.; and non-resonant short-range impurities. In order to study the effect of these types of disorder on graphene's electronic properties and Raman spectra simultaneously, we have developed a facility combining thermal deposition, ion bombardment, electrical transport and micro-Raman measurements in an ultra high vacuum environment. We will discuss the capabilities of this facility and present the results of Raman and electrical transport measurements on controllably disordered graphene.

  13. The large volume radiometric calorimeter system: A transportable device to measure scrap category plutonium

    SciTech Connect

    Duff, M.F.; Wetzel, J.R.; Breakall, K.L.; Lemming, J.F.

    1987-01-01

    An innovative design concept has been used to design a large volume calorimeter system. The new design permits two measuring cells to fit in a compact, nonevaporative environmental bath. The system is mounted on a cart for transportability. Samples in the power range of 0.50 to 12.0 W can be measured. The calorimeters will receive samples as large as 22.0 cm in diameter by 43.2 cm high, and smaller samples can be measured without lengthening measurement time or increasing measurement error by using specially designed sleeve adapters. This paper describes the design considerations, construction, theory, applications, and performance of the large volume calorimeter system. 2 refs., 5 figs., 1 tab.

  14. Measurement and Improved Understanding of Vertical Transport and the Evaluation of these Processes in Mesoscale Models

    SciTech Connect

    David Parsons, James Pinto, William Brown, Stephen Cohn, Bruce Morley

    2007-02-13

    The NCAR effort is primarily focused on the analysis of a diverse suite of measurements taken at the southern end of the Salt Lake City Valley within the Jordan Narrows. These measurements include wind profiler, surface, lidar, radiosonde, multi-layered tether-sonde and sodar measurements. We are also collaborating with other VTMX investigators through linking our measurements within the Jordan Narrows with their investigations. The instrumentation was provided to interested VTMX investigators and was used extensively. Thus the NCAR data set played a large role in the results of the overall experiment. Our work under this proposal includes analysis of the observations, mesoscale modeling efforts in support of our VTMX analysis and general instrumentation development aimed at improving the measurement of vertical transport and mixing under stable conditions. This report is subdivided by research objectives.

  15. Review of Skin Friction Measurements Including Recent High-Reynolds Number Results from NASA Langley NTF

    NASA Technical Reports Server (NTRS)

    Watson, Ralph D.; Hall, Robert M.; Anders, John B.

    2000-01-01

    This paper reviews flat plate skin friction data from early correlations of drag on plates in water to measurements in the cryogenic environment of The NASA Langley National Transonic Facility (NTF) in late 1996. The flat plate (zero pressure gradient with negligible surface curvature) incompressible skin friction at high Reynolds numbers is emphasized in this paper, due to its importance in assessing the accuracy of measurements, and as being important to the aerodynamics of large scale vehicles. A correlation of zero pressure gradient skin friction data minimizing extraneous effects between tests is often used as the first step in the calculation of skin friction in complex flows. Early data compiled by Schoenherr for a range of momentum thickness Reynolds numbers, R(sub Theta) from 860 to 370,000 contained large scatter, but has proved surprisingly accurate in its correlated form. Subsequent measurements in wind tunnels under more carefully controlled conditions have provided inputs to this database, usually to a maximum R(sub Theta) of about 40,000. Data on a large axisymmetric model in the NASA Langley National Transonic Facility extends the upper limit in incompressible R(sub Theta) to 619,800 using the van Driest transformation. Previous data, test techniques, and error sources ar discussed, and the NTF data will be discussed in detail. The NTF Preston tube and Clauser inferred data accuracy is estimated to be within -2 percent of a power-law curve fit, and falls above the Spalding theory by 1 percent at R(sub Theta) of about 600,000.

  16. Sediment transport time measured with U-Series isotopes: Resultsfrom ODP North Atlantic Drill Site 984

    SciTech Connect

    DePaolo, Donald J.; Maher, Kate; Christensen, John N.; McManus,Jerry

    2006-06-05

    High precision uranium isotope measurements of marineclastic sediments are used to measure the transport and storage time ofsediment from source to site of deposition. The approach is demonstratedon fine-grained, late Pleistocene deep-sea sediments from Ocean DrillingProgram Site 984A on the Bjorn Drift in the North Atlantic. The sedimentsare siliciclastic with up to 30 percent carbonate, and dated by sigma 18Oof benthic foraminifera. Nd and Sr isotopes indicate that provenance hasoscillated between a proximal source during the last three interglacialperiods volcanic rocks from Iceland and a distal continental sourceduring glacial periods. An unexpected finding is that the 234U/238Uratios of the silicate portion of the sediment, isolated by leaching withhydrochloric acid, are significantly less than the secular equilibriumvalue and show large and systematic variations that are correlated withglacial cycles and sediment provenance. The 234U depletions are inferredto be due to alpha-recoil loss of234Th, and are used to calculate"comminution ages" of the sediment -- the time elapsed between thegeneration of the small (<_ 50 mu-m) sediment grains in the sourceareas by comminution of bedrock, and the time of deposition on theseafloor. Transport times, the difference between comminution ages anddepositional ages, vary from less than 10 ky to about 300 to 400 ky forthe Site 984A sediments. Long transport times may reflect prior storagein soils, on continental shelves, or elsewhere on the seafloor. Transporttime may also be a measure of bottom current strength. During the mostrecent interglacial periods the detritus from distal continental sourcesis diluted with sediment from Iceland that is rapidly transported to thesite of deposition. The comminution age approach could be used to dateQuaternary non-marine sediments, soils, and atmospheric dust, and may beenhanced by concomitant measurement of 226Ra/230Th, 230Th/234U, andcosmogenic nuclides.

  17. Differences in rating curve and hydrograph uncertainty due to streamflow dynamics and number of discharge measurements

    NASA Astrophysics Data System (ADS)

    Rosenstand Poulsen, Jane; Bering Ovesen, Niels; Larsen, Søren Erik; Tornbjerg, Henrik

    2015-04-01

    The uncertainty related to the use of rating curves for hydrograph estimation is strongly affected if changes in cross-sectional geometry or friction properties occur, especially if the changes are abrupt. In lowland moderately sized streams in temperate regions, such flow changes are often associated with seasonal weed growth. The gradual increase in channel bed roughness caused by weed growth is commonly accounted for by a likewise gradual shift of the rating curve according to monthly discharge measurements. However, this measurement approach is sensitive to abrupt changes in flow, which occur for instance in dynamic streams exhibiting a large difference between maximum and minimum flow or during high summer flows or winter flooding. Hence, the purpose of this study is to investigate the role that dynamic versus stable streams play in terms of uncertainty of establishing rating curves and calculating hydrographs with the traditional stage-discharge approach. Such an analysis is highly valuable in terms of addressing the possibility of adapting hydrograph estimation procedures to the specific streamflow dynamics, thereby quantifying and potentially lowering the uncertainty of hydrograph estimates. Based on results from the Danish national rainfall-runoff model, ratios between yearly median maximum and median minimum stream discharge were calculated for 15 km2 sub-catchments for the entire country. Based on these values, ten gauging stations were selected, located to cover the range of flow regimes represented by the calculated max/min discharge ratios. The selected gauging stations were all stations that had at least three consecutive years with historical data series where direct stream discharge had been measured twenty or more times each year. Based on these data series, new sub-series were created by continuously thinning out the number of discharge measurements. Then, for each of these constructed data series a rating curve and a hydrograph were established according to the Danish standard procedure. After this, a statistical analysis was conducted to evaluate the influence of both flow regime and the number of direct discharge measurements on the deviations and uncertainties of the hydrographs.

  18. Polysulfide transport through separators measured by a linear voltage sweep method

    NASA Astrophysics Data System (ADS)

    Cui, Yi; Fu, Yongzhu

    2015-07-01

    Shuttle of polysulfide from the sulfur cathode to lithium metal anode in rechargeable lithium-sulfur batteries is a critical issue hindering cycling efficiency and life. Several approaches have been developed to minimize it including polysulfide-blocking separators; there is a need for measuring polysulfide transport through separators. We here show a linear voltage sweep method to measure anodic (oxidization) current of polysulfide crossed separators, which can be used as a quantitative measurement of the polysulfide transport. The electrochemical oxidation of polysulfide is diffusion controlled. The electrical charge in Coulombs produced by the oxidation of polysulfide is linearly related to the concentration of polysulfide within a certain range (?0.5 M). Separators with a high porosity (large pore size) show high anodic currents, resulting in fast capacity degradation and low Coulombic efficiencies in Li-S cells. These results demonstrate this method can be used to correlate the polysulfide transport through separators with the separator structure and battery performance, therefore provide guidance for developing new separators for lithium-sulfur batteries.

  19. Particle Number Density Measurement of Sputtered Aluminium Atoms in an Argon Hollow Cathode Glow Discharge

    NASA Astrophysics Data System (ADS)

    Scheibner, Helmar; Behnke, Jürgen F.; Dinklage, Andreas; Franke, Steffen; Wilke, Christian

    2000-10-01

    Direct current hollow cathode glow discharges are qualified for spectroscopic application and for the study of sputtering processes. By means of diode laser spectroscopy the particle number density of sputtered aluminium atoms in the negative glow of a cylindrical dc hollow cathode glow discharge in argon was investigated (pressure p = 1.5 Torr, current i = 10 mA ldots 30 mA, aluminium hollow cathode: diameter d = 7 mm, lenght l = 30 mm). The absorption measurements followed on the both aluminium resonance lines (396.153 nm, 394.403 nm) combining with the two ground state sublevels ^2P_3/2 and ^2P_1/2. In contrast to earlier absorption measurements with a usual line radiator as light source here absorption line profiles were sampled by the narrowband radiation of a tunable blue-emitting GaN diode laser. The wavelength of the laser radiation was scanned with help of a piezoelectric element and the mode hop-free function of the diode laser was checked by a Fabry-Perot resonator with a free spectral range of 2 GHz. The investigations demonstrate the qualification of the blue-emitting laser diode for spectroscopic measurements and yield better absorption spectroscopic results on the basis of exact line profiles.

  20. Method and apparatus for measuring coupled flow, transport, and reaction processes under liquid unsaturated flow conditions

    DOEpatents

    McGrail, Bernard P. (Pasco, WA); Martin, Paul F. (Richland, WA); Lindenmeier, Clark W. (Richland, WA)

    1999-01-01

    The present invention is a method and apparatus for measuring coupled flow, transport and reaction processes under liquid unsaturated flow conditions. The method and apparatus of the present invention permit distinguishing individual precipitation events and their effect on dissolution behavior isolated to the specific event. The present invention is especially useful for dynamically measuring hydraulic parameters when a chemical reaction occurs between a particulate material and either liquid or gas (e.g. air) or both, causing precipitation that changes the pore structure of the test material.

  1. Fluorescent contacts measure the coordination number and entropy of a 3D jammed emulsion packing

    E-print Network

    J. Brujic; G. Marty; C. Song; C. Briscoe; H. A. Makse

    2006-05-31

    Jammed matter is by definition impenetrable to light, rendering the characterization of the 3D geometry difficult. Confocal microscopy of a dyed, refractive index matched emulsion nevertheless allows one to image the jammed system. Here we explain the origin of the mechanism of enhanced fluorescence at the contacts of jammed emulsion droplets in terms of a blue-shifted fluorescence emission band due to the change in the polarity of the interfacial environment. We then use this information to determine the contact network in the emulsion, which models a frictionless jammed system. This enables the experimental determination of the average coordination number, $$ giving the theoretically predicted value of $ \\approx 6$. Furthermore, the method enables the experimental measurement of the entropy of the packing from the network of contacts.

  2. Detailed Measurements of Turbulent Rayleigh-Taylor Mixing at Large and Small Atwood Numbers

    SciTech Connect

    Malcolm J. Andrews, Ph.D.

    2004-12-14

    This project has two major tasks: Task 1. The construction of a new air/helium facility to collect detailed measurements of Rayleigh-Taylor (RT) mixing at high Atwood number, and the distribution of these data to LLNL, LANL, and Alliance members for code validation and design purposes. Task 2. The collection of initial condition data from the new Air/Helium facility, for use with validation of RT simulation codes at LLNL and LANL. Also, studies of multi-layer mixing with the existing water channel facility. Over the last twelve (12) months there has been excellent progress, detailed in this report, with both tasks. As of December 10, 2004, the air/helium facility is now complete and extensive testing and validation of diagnostics has been performed. Currently experiments with air/helium up to Atwood numbers of 0.25 (the maximum is 0.75, but the highest Reynolds numbers are at 0.25) are being performed. The progress matches the project plan, as does the budget, and we expect this to continue for 2005. With interest expressed from LLNL we have continued with initial condition studies using the water channel. This work has also progressed well, with one of the graduate Research Assistants (Mr. Nick Mueschke) visiting LLNL the past two summers to work with Dr. O. Schilling. Several journal papers are in preparation that describe the work. Two MSc.'s have been completed (Mr. Nick Mueschke, and Mr. Wayne Kraft, 12/1/03). Nick and Wayne are both pursuing Ph.D.s' funded by this DOE Alliances project. Presently three (3) Ph.D. graduate Research Assistants are supported on the project, and two (2) undergraduate Research Assistants. During the year two (2) journal papers and two (2) conference papers have been published, ten (10) presentations made at conferences, and three (3) invited presentations.

  3. Quantitative measurement of intracellular transport of nanocarriers by spatio-temporal image correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Coppola, S.; Pozzi, D.; Candeloro De Sanctis, S.; Digman, M. A.; Gratton, E.; Caracciolo, G.

    2013-03-01

    Spatio-temporal image correlation spectroscopy (STICS) is a powerful technique for assessing the nature of particle motion in complex systems although it has been rarely used to investigate the intracellular dynamics of nanocarriers so far. Here we introduce a method for characterizing the mode of motion of nanocarriers and for quantifying their transport parameters on different length scales from single-cell to subcellular level. Using this strategy we were able to study the mechanisms responsible for the intracellular transport of DOTAP-DOPC/DNA (DOTAP: 1,2-dioleoyl-3-trimethylammonium-propane; DOPC: dioleoylphosphocholine) and DC-Chol-DOPE/DNA (DC-Chol: 3?-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol; DOPE: dioleoylphosphatidylethanolamine) lipoplexes in CHO-K1 (CHO: Chinese hamster ovary) live cells. Measurement of both diffusion coefficients and velocity vectors (magnitude and direction) averaged over regions of the cell revealed the presence of distinct modes of motion. Lipoplexes diffused slowly on the cell surface (diffusion coefficient: D ? 0.003 ?m2 s-1). In the cytosol, the lipoplexes’ motion was characterized by active transport with average velocity v ? 0.03 ?m2 s-1 and random motion. The method permitted us to generate an intracellular transport map showing several regions of concerted motion of lipoplexes.

  4. Prevalence of transportation safety measures portrayed in primetime US television programs and commercials

    PubMed Central

    McGwin, G; Modjarrad, K; Reiland, A; Tanner, S; Rue, L W

    2006-01-01

    Objective To determine the prevalence of transportation related safety behaviors, such as seatbelt and helmet use, in primetime US television programs and commercials. Design Cross sectional study. Setting Top rated television programs and associated commercials from four major US television networks were reviewed for the prevalence of transportation safety related behaviors during a one month period in 2005. Programs were categorized according to the time and network of airing, program type, program rating, and—for commercials—type of product being advertised Subjects Occupants of automobiles, motorcycles, or bicycles in 507 instances in which a transportation scene was aired. Results Seatbelt use was depicted in 62% and 86% of individuals in television program and commercial automobile scenes, respectively. The prevalence of motorcycle helmet use was 47% in television programs and 100% in commercials. Bicycle helmets were used in 9% of television programs and 84% of commercials. The frequency of seatbelt use in programs and commercials varied by television rating and genre but did not differ by network, time of airing, or age of character portrayed. Conclusions The prevalence of safety related behaviors aired on major US networks during primetime slots is higher than previous reports but still much lower than national averages. Commercials, in contrast, portray transportation safety measures with a frequency that exceeds that of US television programs or most national surveys. PMID:17170190

  5. Measurements of ultrafine particles carrying different number of charges in on- and near-freeway environments

    NASA Astrophysics Data System (ADS)

    Lee, Eon S.; Xu, Bin; Zhu, Yifang

    2012-12-01

    This paper presents measurements of electrical charges on ultrafine particles (UFPs) of different electrical mobility diameters (30, 50, 80, and 100 nm) in on- and near-freeway environments. Using a tandem Differential Mobility Analyzer (DMA) system, we first examined the fraction of UFPs carrying different number of charges on two distinctive freeways: a gasoline-vehicle dominated freeway (I-405) and a heavy-duty diesel truck dominated freeway (I-710). The fractions of UFPs of a given size carrying one or more charges were significantly higher on the freeways than in the background. The background UFPs only carried up to two charges but freeway UFPs could have up to three charges. The total fraction of charged particles was higher on the I-710 than I-405 across the studied electrical mobility diameters. Near the I-405 freeway, we observed a strong decay of charged particles on the downwind side of the freeway. We also found fractional decay of the charged particles was faster than total particle number concentrations, but slower than total ion concentrations downwind from the freeway I-405. Among charged particles, the highest decay rate was observed for particles carrying three charges. Near the I-710 freeway, we found strong net positive charges on nucleation mode particles, suggesting that UFPs were not at steady-state charge equilibrium near freeways.

  6. Externally driven global Alfvén eigenmodes applied for effective mass number measurement on TCABR

    SciTech Connect

    Puglia, P. G. P. P.; Elfimov, A. G.; Ruchko, L. F.; Galvão, R. M. O.; Guimarães-Filho, Z.; Ronchi, G.

    2014-12-15

    The excitation and detection of Global Alfvén Eigenmodes on TCABR for diagnostic purposes are presented. The modes can be excited with one or two in-vessel antennae, with up to 15?A of current in each, in the frequency range from 2 to 4 MHz. This scheme allows the estimation of the effective mass number at the plasma center, which value is affected by impurity concentration in the core. An amplifier based on MOSFETs is used to excite the waves driven by low power, in order to not change the basic plasma parameters. The variation of the GAE with density is verified and the location of the mode resonance at the plasma center is confirmed by the sawtooth beating, so that the correspondingly beating phase inversion improves the precision on the resonant condition determination. The toroidal parity of the modes N?=?1,2 is determined by use of two opposite located antennae with different phase of the RF current. Knowledge of toroidal mode number is important as it identifies GAE location and defines the estimated effective mass value. The estimated value for A{sub eff} is ?1.4–1.5, corresponding to 5–7% of carbon impurity concentration. The measured value of A{sub eff} is used to estimate Z{sub eff}, which is compared to older TCA experiments and the value obtained by the Spitzer conductivity.

  7. Automated 3D trajectory measuring of large numbers of moving particles.

    PubMed

    Wu, Hai Shan; Zhao, Qi; Zou, Danping; Chen, Yan Qiu

    2011-04-11

    Complex dynamics of natural particle systems, such as insect swarms, bird flocks, fish schools, has attracted great attention of scientists for years. Measuring 3D trajectory of each individual in a group is vital for quantitative study of their dynamic properties, yet such empirical data is rare mainly due to the challenges of maintaining the identities of large numbers of individuals with similar visual features and frequent occlusions. We here present an automatic and efficient algorithm to track 3D motion trajectories of large numbers of moving particles using two video cameras. Our method solves this problem by formulating it as three linear assignment problems (LAP). For each video sequence, the first LAP obtains 2D tracks of moving targets and is able to maintain target identities in the presence of occlusions; the second one matches the visually similar targets across two views via a novel technique named maximum epipolar co-motion length (MECL), which is not only able to effectively reduce matching ambiguity but also further diminish the influence of frequent occlusions; the last one links 3D track segments into complete trajectories via computing a globally optimal assignment based on temporal and kinematic cues. Experiment results on simulated particle swarms with various particle densities validated the accuracy and robustness of the proposed method. As real-world case, our method successfully acquired 3D flight paths of fruit fly (Drosophila melanogaster) group comprising hundreds of freely flying individuals. PMID:21503074

  8. Measurements of mass attenuation coefficient, effective atomic number and electron density of some amino acids

    NASA Astrophysics Data System (ADS)

    Kore, Prashant S.; Pawar, Pravina P.

    2014-05-01

    The mass attenuation coefficients of some amino acids, such as DL-aspartic acid-LR(C4H7NO4), L-glutamine (C4H10N2O3), creatine monohydrate LR(C4H9N3O2H2O), creatinine hydrochloride (C4H7N3O·HCl) L-asparagine monohydrate(C4H9N3O2H2O), L-methionine LR(C5H11NO2S), were measured at 122, 356, 511, 662, 1170, 1275 and 1330 keV photon energies using a well-collimated narrow beam good geometry set-up. The gamma-rays were detected using NaI (Tl) scintillation detection system with a resolution of 0.101785 at 662 keV. The attenuation coefficient data were then used to obtain the effective atomic numbers (Zeff), and effective electron densities (Neff) of amino acids. It was observed that the effective atomic number (Zeff) and effective electron densities (Neff) initially decrease and tend to be almost constant as a function of gamma-ray energy. Zeff and Neff experimental values showed good agreement with the theoretical values with less than 1% error for amino acids.

  9. Compensation of the exhaust gas transport dynamics for accurate instantaneous emission measurements.

    PubMed

    Ajtay, Delia; Weilenmann, Martin

    2004-10-01

    Instantaneous emission models of vehicles describe the amount of emitted pollutants as a function of the driving state of the car. Emission measurements of chassis dynamometer tests with high time resolution are necessary for the development of such models. However, the dynamics of gas transport in both the exhaust system of the car and the measurement line last significantly longer than 1 s. In a simplified approach, the transport dynamics can be divided into two parts: a perfect time delay, corresponding to a piston-like transport of the exhaust gas, and a dynamic part, corresponding to the mixing of gases by turbulence along the way. This determines the occurrence of emission peaks that are longer in time and lower in height at the analyzer than they actually are in the vehicle at their location of formation. It is shown here how the sharp emission signals at their location of formation can be reconstructed from the flattened emission signals recorded at the analyzer by using signal theory approaches. A comparison between the reconstructions quality when using the raw or the dilution analyzer system is also given. PMID:15506210

  10. Measuring Phonon Mean Free Path Distributions by Probing Quasiballistic Phonon Transport in Grating Nanostructures

    PubMed Central

    Zeng, Lingping; Collins, Kimberlee C.; Hu, Yongjie; Luckyanova, Maria N.; Maznev, Alexei A.; Huberman, Samuel; Chiloyan, Vazrik; Zhou, Jiawei; Huang, Xiaopeng; Nelson, Keith A.; Chen, Gang

    2015-01-01

    Heat conduction in semiconductors and dielectrics depends upon their phonon mean free paths that describe the average travelling distance between two consecutive phonon scattering events. Nondiffusive phonon transport is being exploited to extract phonon mean free path distributions. Here, we describe an implementation of a nanoscale thermal conductivity spectroscopy technique that allows for the study of mean free path distributions in optically absorbing materials with relatively simple fabrication and a straightforward analysis scheme. We pattern 1D metallic grating of various line widths but fixed gap size on sample surfaces. The metal lines serve as both heaters and thermometers in time-domain thermoreflectance measurements and simultaneously act as wire-grid polarizers that protect the underlying substrate from direct optical excitation and heating. We demonstrate the viability of this technique by studying length-dependent thermal conductivities of silicon at various temperatures. The thermal conductivities measured with different metal line widths are analyzed using suppression functions calculated from the Boltzmann transport equation to extract the phonon mean free path distributions with no calibration required. This table-top ultrafast thermal transport spectroscopy technique enables the study of mean free path spectra in a wide range of technologically important materials. PMID:26612032

  11. Measurements of AC losses due to transport currents in bismuth superconductors

    NASA Astrophysics Data System (ADS)

    Ashworth, S. P.

    1994-08-01

    Measurements of the losses of BSCCO-2223 and BSCCO-2212 tapes carrying AC transport currents are reported. Measurements were made at 77 K at frequencies in the range 20-60 Hz. The voltage waveforms generated by the AC transport are presented as well as the AC losses. For peak transport currents below 90% of the DC critical current the losses of BSCCO-2223 tapes are shown to be well described using an equation due to Norris [5] which assumes the presence of a critical state in the superconductor, and the power losses are proportional to the AC frequency (hysteresis losses). When the AC peak current approaches the DC critical current flux-creep effects dominate the losses, and the power losses cease to depend on frequency. In the BSCCO-2212 sample flux-creep effects dominate at all currents. The examination of the voltage waveform generated in the BSCCO-2223 sample shows the presence of both hysteretic and flux-creep generated voltages.

  12. Measuring Phonon Mean Free Path Distributions by Probing Quasiballistic Phonon Transport in Grating Nanostructures.

    PubMed

    Zeng, Lingping; Collins, Kimberlee C; Hu, Yongjie; Luckyanova, Maria N; Maznev, Alexei A; Huberman, Samuel; Chiloyan, Vazrik; Zhou, Jiawei; Huang, Xiaopeng; Nelson, Keith A; Chen, Gang

    2015-01-01

    Heat conduction in semiconductors and dielectrics depends upon their phonon mean free paths that describe the average travelling distance between two consecutive phonon scattering events. Nondiffusive phonon transport is being exploited to extract phonon mean free path distributions. Here, we describe an implementation of a nanoscale thermal conductivity spectroscopy technique that allows for the study of mean free path distributions in optically absorbing materials with relatively simple fabrication and a straightforward analysis scheme. We pattern 1D metallic grating of various line widths but fixed gap size on sample surfaces. The metal lines serve as both heaters and thermometers in time-domain thermoreflectance measurements and simultaneously act as wire-grid polarizers that protect the underlying substrate from direct optical excitation and heating. We demonstrate the viability of this technique by studying length-dependent thermal conductivities of silicon at various temperatures. The thermal conductivities measured with different metal line widths are analyzed using suppression functions calculated from the Boltzmann transport equation to extract the phonon mean free path distributions with no calibration required. This table-top ultrafast thermal transport spectroscopy technique enables the study of mean free path spectra in a wide range of technologically important materials. PMID:26612032

  13. The Measurement of the Number of Light Neutrino Species at LEP

    NASA Astrophysics Data System (ADS)

    Mele, Salvatore

    2015-07-01

    Within weeks of the start of the data taking at the LEP accelerator, the ALEPH, DELPHI, L3 and OPAL experiments were able to confirm the existence of just three light neutrino species. This measurement relies on the Standard Model relation between the `invisible' width of the Z-boson and the cross-sections for Z-boson production and subsequent decay into hadrons. The full data sample collected by the experiments at and around the Z-boson resonance allows a high-precision measurement of the number of light neutrino species as 2.9840 ± 0.0082. The uncertainty is mostly due to the understanding of the low-angle Bhabha scattering process used to determine the experimental luminosity. This result is independently confirmed by the elegant direct observation of the e^-e^+ to ? bar{?}? process, through the detection of an initial-state-radiation photon in otherwise empty detectors. This result confirms expectations from the existence of three charged leptons species, and contributes to the fields of astrophysics and cosmology. Alongside other LEP achievements, the precision of this result is a testament to the global cooperation underpinning CERN's fourth decade. LEP saw the onset of large-scale collaboration across experiments totaling over 2000 scientists, together with a strong partnership within the wider high-energy physics community: from accelerator operations to the understanding of theoretical processes.

  14. Measuring effective radium concentration with large numbers of samples. Part I--experimental method and uncertainties.

    PubMed

    Girault, Frédéric; Perrier, Frédéric

    2012-11-01

    Effective radium concentration EC(Ra), product of radium concentration and radon emanation, is the source term for radon release into the pore space of rocks and the environment. To measure EC(Ra), we have conducted, over a period of three years, more than 5500 radon-222 accumulation experiments in the laboratory with scintillation flasks, and about 700 with integrating solid state nuclear track detectors, leading to experimental values of EC(Ra) for more than 1570 rock and soil samples. Through detailed systematic checks and intercomparison between various repeated experiments, the experimental uncertainty has been assessed, and ranges from 30% (1 ?) for EC(Ra) values smaller than 0.2 Bq kg(-1) to about 8-10% for EC(Ra) values larger than 50 Bq kg(-1). The detection limit, defined as the 90% probability for obtaining a non-zero experimental EC(Ra) value at 68% confidence level, depends on the mass of the sample with respect to the volume of the accumulation volume, and typically varies between 0.04 and 0.09 Bq kg(-1). To measure EC(Ra) from large numbers of samples with sufficient accuracy and uncertainty for our purpose, i.e. for the most natural objects encountered in the environment, the accumulation method with scintillation flask emerged as particularly useful and robust. Properties of EC(Ra) and interpretations inferred from this large data set are presented in the companion paper. PMID:22819081

  15. Utilizing photon number parity measurements to demonstrate quantum computation with cat-states in a cavity

    NASA Astrophysics Data System (ADS)

    Petrenko, A.; Ofek, N.; Vlastakis, B.; Sun, L.; Leghtas, Z.; Heeres, R.; Sliwa, K. M.; Mirrahimi, M.; Jiang, L.; Devoret, M. H.; Schoelkopf, R. J.

    2015-03-01

    Realizing a working quantum computer requires overcoming the many challenges that come with coupling large numbers of qubits to perform logical operations. These include improving coherence times, achieving high gate fidelities, and correcting for the inevitable errors that will occur throughout the duration of an algorithm. While impressive progress has been made in all of these areas, the difficulty of combining these ingredients to demonstrate an error-protected logical qubit, comprised of many physical qubits, still remains formidable. With its large Hilbert space, superior coherence properties, and single dominant error channel (single photon loss), a superconducting 3D resonator acting as a resource for a quantum memory offers a hardware-efficient alternative to multi-qubit codes [Leghtas et.al. PRL 2013]. Here we build upon recent work on cat-state encoding [Vlastakis et.al. Science 2013] and photon-parity jumps [Sun et.al. 2014] by exploring the effects of sequential measurements on a cavity state. Employing a transmon qubit dispersively coupled to two superconducting resonators in a cQED architecture, we explore further the application of parity measurements to characterizing such a hybrid qubit/cat state architecture. In so doing, we demonstrate the promise of integrating cat states as central constituents of future quantum codes.

  16. Describing and compensating gas transport dynamics for accurate instantaneous emission measurement

    NASA Astrophysics Data System (ADS)

    Weilenmann, Martin; Soltic, Patrik; Ajtay, Delia

    Instantaneous emission measurements on chassis dynamometers and engine test benches are becoming increasingly usual for car-makers and for environmental emission factor measurement and calculation, since much more information about the formation conditions can be extracted than from the regulated bag measurements (integral values). The common exhaust gas analysers for the "regulated pollutants" (carbon monoxide, total hydrocarbons, nitrogen oxide, carbon dioxide) allow measurement at a rate of one to ten samples per second. This gives the impression of having after-the-catalyst emission information with that chronological precision. It has been shown in recent years, however, that beside the reaction time of the analysers, the dynamics of gas transport in both the exhaust system of the car and the measurement system last significantly longer than 1 s. This paper focuses on the compensation of all these dynamics convoluting the emission signals. Most analysers show linear and time-invariant reaction dynamics. Transport dynamics can basically be split into two phenomena: a pure time delay accounting for the transport of the gas downstream and a dynamic signal deformation since the gas is mixed by turbulence along the way. This causes emission peaks to occur which are smaller in height and longer in time at the sensors than they are after the catalyst. These dynamics can be modelled using differential equations. Both mixing dynamics and time delay are constant for modelling a raw gas analyser system, since the flow in that system is constant. In the exhaust system of the car, however, the parameters depend on the exhaust volume flow. For gasoline cars, the variation in overall transport time may be more than 6 s. It is shown in this paper how all these processes can be described by invertible mathematical models with the focus on the more complex case of the car's exhaust system. Inversion means that the sharp emission signal at the catalyst out location can be reconstructed from a flattened emission signal at the sensor. In this modelling, special focus is put on finding an easy parameterisation for different cars. The process of finding these compensators consists of first describing the process by differential equations of appropriate order and parameterising them, resulting in low pass systems. The following step of inverting these systems results automatically in high pass systems. These kinds of systems, however, amplify measurement noise, thus they need signal filters to smooth their output.

  17. Comparison of energy transport measurements and computer simulations in a single module prototype for PBFA II

    SciTech Connect

    Neau, E.L.; Seamen, J.F.; Bloomquist, D.D.; Babcock, S.R.; Schneider, L.X.; Sujka, B.R.

    1985-01-01

    The 36-module Particle Beam Fusion Accelerator (PBFA II) is designed to provide a 30 MV pulse, with greater than 150 TW, to a centrally located lithium ion diode. Each module is driven by a 6 MV, 400 kJ Marx generator and uses three water-insulated and switched pulse compression stages followed by a voltage inversion-adder unit. All impedance matching transmission-line transformer couples the output pulse from the inversion-adder unit to the central vacuum insulator, plasma erosion switches, and ion diode. The prototype of a single PBFA-II module, called Demon, is being used to test component design, including a mock-up of a section of the vacuum insulator, and to determine overall module operatting characteristics. This paper presents the results of measurements of energy transport efficiencies through the successive pulse compression stages. Results of energy transport measurements on an 18 module, one-fifth scale model, are also compared to the single-line data. We present a comparison of measured parameters with computer circuit code simulations of the hardware design. Comparisons are used to suggest areas of possible improvements. The measured module output characteristics agree with the code simulations and meet the design requirements for the PBFA-II accelerator.

  18. Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks

    SciTech Connect

    Ban-Weiss, George A.; Lunden, Melissa M.; Kirchstetter, Thomas W.; Harley, Robert A.

    2009-02-02

    Emission factors for black carbon (BC) and particle number (PN) were measured from 226 individual heavy-duty (HD) diesel-fueled trucks driving through a 1 km-long California highway tunnel in August 2006. Emission factors were based on concurrent increases in BC, PN, and CO{sub 2}B concentrations (measured at 1 Hz) that corresponded to the passage of individual HD trucks. The distributions of BC and PN emission factors from individual HD trucks are skewed, meaning that a large fraction of pollution comes from a small fraction of the in-use vehicle fleet. The highest-emitting 10% of trucks were responsible for {approx} 40% of total BC and PN emissions from all HD trucks. BC emissions were log-normally distributed with a mean emission factor of 1.7 g kg {sup -1} and maximum values of {approx} 10 g kg{sup -1}. Corresponding values for PN emission factors were 4.7 x 10{sup 15} and 4 x 10{sup 16} kg{sup -1}. There was minimal overlap among high-emitters of these two pollutants: only 1 of the 226 HD trucks measured was found to be among the highest 10% for both BC and PN. Monte Carlo resampling of the distribution of BC emission factors observed in this study revealed that uncertainties (1{sigma}) in extrapolating from a random sample of n HD trucks to a population mean emission factor ranged from {+-} 43% for n = 10 to {+-} 8% for n = 300, illustrating the importance of sufficiently large vehicle sample sizes in emissions studies. Studies with low sample sizes are also more easily biased due to misrepresentation of high-emitters. As vehicles become cleaner on average in future years, skewness of the emissions distributions will increase, and thus sample sizes needed to extrapolate reliably from a subset of vehicles to the entire in-use vehicle fleet are expected to become more of a challenge.

  19. Airborne lidar measurements of pollution transport in central and southern California during CalNEX 2010

    NASA Astrophysics Data System (ADS)

    Senff, C. J.; Alvarez, R. J., II; Hardesty, R.; Langford, A. O.; Banta, R. M.; Brewer, A.; Davies, F.; Sandberg, S.; Marchbanks, R.; Weickmann, A.

    2010-12-01

    During the CalNEX experiment from May through July 2010, we co-deployed NOAA’s airborne ozone and aerosol lidar TOPAZ and the University of Leeds scanning Doppler wind lidar on a Twin Otter aircraft. We flew a total of 46 missions over central and southern California, focusing primarily on the Los Angeles Basin and Sacramento areas. The downward-looking lidars provided highly resolved measurements of ozone concentration, aerosol backscatter, and wind speed and direction in the boundary layer and lower free troposphere. We will use the airborne lidar data to characterize transport of ozone and aerosols on regional and local scales. In particular, we will focus on pollutant transport between air basins and the role of flow patterns in complex terrain, such as gap flows and orographic lifting and venting along mountain slopes, on pollutant distribution.

  20. Measurement of cross-magnetic-field heat transport due to long-range collisions

    NASA Astrophysics Data System (ADS)

    Hollmann, E. M.; Anderegg, F.; Driscoll, C. F.

    2000-05-01

    Cross-magnetic-field heat transport in a quiescent pure ion plasma is found to be diffusive and to be dominated by long-range "guiding center" collisions. In these long-range collisions, which occur in plasmas with Debye length ?D greater than cyclotron radius rc, particles with impact parameters rcmeasured thermal diffusivity ? agrees within a factor of 2 with the long-range prediction ?L=0.49nv¯b2?D2 over a range of 1000 in temperature, 50 in density, and 4 in magnetic field. This thermal diffusivity is observed to be up to 100 times larger than classical diffusivity from short-range velocity-scattering collisions. These long-range collisions are typically dominant in unneutralized plasmas, and may also contribute to electron heat transport in neutral plasmas.

  1. Measurement of Cross-Magnetic-Field Heat Transport in a Pure Ion Plasma

    NASA Astrophysics Data System (ADS)

    Hollmann, E. M.; Anderegg, F.; Driscoll, C. F.

    1999-06-01

    Cross-magnetic-field heat transport in a quiescent pure ion plasma is found to be diffusive and to be dominated by long-range collisions with impact parameters up to a Debye length. The measured thermal diffusivity ? agrees within a factor of 2 with the long-range prediction ?L = 0.49nv¯b2?2D over a range of 103 in temperature, 50 in density, and 4 in magnetic field. This thermal diffusivity is independent of magnetic field strength, and is observed to be up to 100 times larger than the classical diffusivity. These long-range collisions are typically dominant in unneutralized plasmas, and may also contribute to electron heat transport in neutral plasmas.

  2. Measurement of cross-magnetic-field heat transport due to long range collisions

    NASA Astrophysics Data System (ADS)

    Hollmann, E. M.; Anderegg, F.; Driscoll, C. F.

    1999-12-01

    Cross-magnetic-field heat transport in a quiescent pure ion plasma is found to be diffusive and to be dominated by long-range "guiding center" collisions. In these long-range collisions, which occur in plasmas with ?D>rc, particles with impact parameters rcmeasure a thermal diffusivity ? which agrees within a factor of 2 with the long-range prediction ?L=0.49nv¯b2?D2 over a range of 103 in temperature, 50 in density, and 4 in magnetic field. This thermal diffusivity is observed to be up to 100 times larger than the classical diffusivity. These long-range collisions are typically dominant in unneutralized plasmas, and may also contribute to electron heat transport in neutral plasmas.

  3. Transport and Measurements of High-Current Electron Beams from X pinches

    SciTech Connect

    Agafonov, Alexey V.; Mingaleev, Albert R.; Romanova, Vera M.; Tarakanov, Vladimir P.; Shelkovenko, Tatiana A.; Pikuz, Sergey A.; Blesener, Isaac C.; Kusse, Bruce R.; Hammer, David A.

    2009-01-21

    Generation of electron beams is an unavoidable property of X-pinches and other pulsed-power-driven pinches of different geometry. Some issues concerning high-current electron beam transport from the X pinch to the diagnostic system and measurements of the beam current by Faraday cups with different geometry's are discussed. Of particular interest is the partially neutralized nature of the beam propagating from the X-pinch to a diagnostic system. Two scenarios of electron beam propagation from X-pinch to Faraday cup are analyzed by means of computer simulation using the PIC-code KARAT. The first is longitudinal neutralization by ions extracted from plasma at an output window of the X-pinch diode; the second is the beam transport through a plasma background between the diode and a diagnostic system.

  4. Dust and pollution transport on global scales: Aerosol measurements and model predictions

    NASA Astrophysics Data System (ADS)

    Clarke, A. D.; Collins, W. G.; Rasch, P. J.; Kapustin, V. N.; Moore, K.; Howell, S.; Fuelberg, H. E.

    2001-12-01

    Vertical profiles of aerosol and gas phase species were measured on flights near Hawaii on April 9 and 10, 1999, during NASA's Pacific Exploratory Mission (PEM) Tropics B program. These measurements characterized aerosol microphysics, inferred chemistry, optical properties, and gases in several extensive dust and pollution plumes, also detected by satellites, which had 10,000-km trajectories back to sources in Asia. Size-resolved measurements indicative of aerosol sulfate, black carbon, dust, light scattering, and absorption allowed determination of their concentrations and contributions to column aerosol optical depth. A new Chemical Transport Model (CTM) that includes aerosol, meteorological fields, dynamics, gas and particle source emissions, a chemistry component (MATCH), and assimilated satellite data was used to predict aerosol and gas concentrations and the aerosol optical effects along our flight path. Flight measurements confirmed the "river-like" plume structures predicted by the CTM and showed close agreement with the predicted contributions of dust and sulfate to aerosol concentrations and optical properties for this global-scale transport path. Consistency between satellite, model and in situ assessment of aerosol optical depth was found, with noted exceptions, within ˜25%. Both observations and model results confirmed that this aerosol was being entrained into the marine boundary layer between Hawaii and California where it can be expected to modify the type and concentration of cloud condensation nuclei in ways that may alter properties of low-level clouds. These observations document the significance and complexity of long-range aerosol transport and highlight the potential of emerging CTM models to extend observational data and address related issues on global scales.

  5. Spray washing, absorbent cornstarch powder, and dry time to reduce bacterial numbers on soiled transport cage flooring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Broiler transport cages are often used repeatedly without washing and fecal matter deposited on the floor surface can transfer Campylobacter from one flock to another. Allowing feces to dry is an effective but slow and logistically impractical means to kill Campylobacter in soiled transport cages. ...

  6. Controlling and measuring quantum transport of heat in trapped-ion crystals.

    PubMed

    Bermudez, A; Bruderer, M; Plenio, M B

    2013-07-26

    Measuring heat flow through nanoscale devices poses formidable practical difficulties as there is no "ampere meter" for heat. We propose to overcome this problem in a chain of trapped ions, where laser cooling the chain edges to different temperatures induces a heat current of local vibrations (vibrons). We show how to efficiently control and measure this current, including fluctuations, by coupling vibrons to internal ion states. This demonstrates that ion crystals provide an ideal platform for studying quantum transport, e.g., through thermal analogues of quantum wires and quantum dots. Notably, ion crystals may give access to measurements of the elusive bosonic fluctuations in heat currents and the onset of Fourier's law. Our results are strongly supported by numerical simulations for a realistic implementation with specific ions and system parameters. PMID:23931344

  7. CONTROL ENGINEERING VOLUME: 13 | NUMBER: 1 | 2015 | MARCH Impact of measurement dating inaccuracies in the

    E-print Network

    , network monitoring. 1. Introduction In this article, we wish to stress the negative role on data analysis applications. In various industrial fields, conveyor systems (or pipes) are used to transport bulk material

  8. A Transport Analysis of In Situ Airborne Ozone Measurements from the 2011 DISCOVER-AQ Campaign

    NASA Astrophysics Data System (ADS)

    Arkinson, H. L.; Brent, L. C.; He, H.; Loughner, C.; Stehr, J. W.; Weinheimer, A. J.; Dickerson, R. R.

    2013-12-01

    Baltimore and Washington are currently designated as nonattainment areas with respect to the 2008 EPA National Ambient Air Quality Standard (NAAQS) for 8-hour Ozone (O3). Tropospheric O3 is the dominant component of summertime photochemical smog, and at high levels, has deleterious effects on human health, ecosystems, and materials. The University of Maryland (UMD) Regional Atmospheric Measurement Modeling and Prediction Program (RAMMPP) strives to improve understanding of air quality in the Mid-Atlantic States and to elucidate contributions of pollutants such as O3 from regional transport versus local sources through a combination of modeling and in situ measurements. The NASA Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) project investigates the connection between column measurements and surface conditions to explore the potential of remote sensing observations in diagnosing air quality at ground level where pollutants can affect human health. During the 2011 DISCOVER-AQ field campaign, in situ airborne measurements of trace gases and aerosols were performed along the Interstate 95 corridor between Baltimore and Washington from the NASA P3B aircraft. To augment this data and provide regional context, measurements of trace gases and aerosols were also performed by the RAMMPP Cessna 402B aircraft over nearby airports in Maryland and Virginia. This work presents an analysis of O3 measurements made by the Ultraviolet (UV) Photometric Ambient O3 Analyzer on the RAMMPP Cessna 402B and by the NCAR 4-Channel Chemiluminescence instrument on the NASA P3B. In this analysis, spatial and temporal patterns of O3 data are examined within the context of forward and backward trajectories calculated from 12-km North American Mesoscale (NAM) meteorological data using the NOAA Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model and from a high resolution Weather Research and Forecasting (WRF) model simulation in order to discern O3 resulting from regional transport versus O3 generated photochemically from local pollution sources. During the summer 2011 DISCOVER-AQ field campaign, both aircraft flew on eight overlapping dates. From the spirals performed on those flight days, over 15 cases have been identified where measurements of O3 were performed with one aircraft upwind of the other, based on forward and backward trajectory data. Analysis of these cases indicates that regional transport of O3 is enhanced up to 10% on average by local photochemical O3 production.

  9. Evaluation of the measurement of AC transport current loss in assembled HTS tapes using a pick-up loop

    NASA Astrophysics Data System (ADS)

    Ogawa, J.; Fukui, S.; Oka, T.; Yamaguchi, M.; Sato, T.; Yamaya, K.; Hamada, T.; Tanaka, H.

    2007-10-01

    In this study, we investigated AC transport current measurement using a pick-up loop. In a single HTS tape the correction factors for different pick-up loop shapes correspond with the experimental and numerical results. In an assembled conductor, we experimentally investigated the difference in the correction factors for the serial and parallel connected transport current in each HTS tape. In parallel mode, the correction factor has a constant value against the total transport current, while in serial mode the correction factor varies. These results can be explained by the relation between the transport current distribution in each HTS tape and the position of the pick-up loops.

  10. Phase-controlled, heterodyne laser-induced transient grating measurements of thermal transport properties in opaque material

    E-print Network

    Johnson, Jeremy A.

    The methodology for a heterodyned laser-induced transient thermal grating technique for non-contact, non-destructive measurements of thermal transport in opaque material is presented. Phase-controlled heterodyne detection ...

  11. Thermal transport in CO2 laser irradiated fused silica: in situ measurements and analysis

    SciTech Connect

    Yang, S T; Matthews, M J; Elhadj, S; Draggoo, V G; Bisson, S E

    2009-07-07

    In situ spatial and temporal temperature measurements of pristine fused silica surfaces heated with a 10.6 {micro}m CO{sub 2} laser were obtained using an infrared radiation thermometer based on a Mercury Cadmium Telluride (MCT) camera. Laser spot sizes ranged from 250 {micro}m to 1000 {micro}m diameter with peak axial irradiance levels of 0.13 to 16 kW/cm{sup 2}. For temperatures below 2800K, the measured steady-state surface temperature is observed to rise linearly with both increasing beam size and incident laser irradiance. The effective thermal conductivity estimated over this range was approximately 2W/mK, in good agreement with classical calculations based on phonon heat capacities. Similarly, time-dependent temperature measurements up to 2000K yielded thermal diffusivity values which were close to reported values of 7 x 10{sup -7} m{sup 2}/s. Above {approx}2800K, the fused silica surface temperature asymptotically approaches 3100K as laser power is further increased, consistent with the onset of evaporative heat losses near the silica boiling point. These results show that in the laser heating regime studied here, the T{sup 3} temperature dependent thermal conductivity due to radiation transport can be neglected, but at temperatures above 2800K heat transport due to evaporation must be considered. The thermal transport in fused silica up to 2800K, over a range of conditions, can then be adequately described by a linear diffusive heat equation assuming constant thermal properties.

  12. Direct, Absolute, and In Situ Measurement of Fast Electron Transport via Cherenkov Emission

    SciTech Connect

    Habara, Hideaki; Ohta, Kazuhide; Tanaka, Kazuo A.; Kumar, G. Ravindra; Krishnamurthy, M.; Kahaly, Subhendu; Mondal, Sudipta; Bhuyan, Manoj Kumar; Rajeev, R.; Zheng Jian

    2010-02-05

    We present direct measurements of the absolute energy distribution of relativistic electrons generated in intense, femtosecond laser interaction with a solid. Cherenkov emission radiated by these electrons in a novel prism target is spectrally dispersed to obtain yield and energy distribution of electrons simultaneously. A crucial advance is the observation of high density electron current as predicted by particle simulations and its transport as it happens inside the target. In addition, the strong sheath potential present at the rear side of the target is inferred from a comparison of the electron spectra derived from Cherenkov light observation with that from a magnet spectrometer.

  13. Temperature dependent spin transport properties of platinum inferred from spin Hall magnetoresistance measurements

    SciTech Connect

    Meyer, Sibylle Althammer, Matthias; Geprägs, Stephan; Opel, Matthias; Goennenwein, Sebastian T. B.; Gross, Rudolf

    2014-06-16

    We study the temperature dependence of the spin Hall magnetoresistance (SMR) in yttrium iron garnet/platinum hybrid structures via magnetization orientation dependent magnetoresistance measurements. Our experiments show a decrease of the SMR magnitude with decreasing temperature. Using the sensitivity of the SMR to the spin transport properties of the normal metal, we interpret our data in terms of a decrease of the spin Hall angle in platinum from 0.11 at room temperature to 0.075 at 10?K, while the spin diffusion length and the spin mixing conductance of the ferrimagnetic insulator/normal metal interface remain almost constant.

  14. Measurement of temperature, density, and particle transport with localized dopants in wire-array Z pinches.

    PubMed

    Jones, B; Deeney, C; McKenney, J L; Ampleford, D J; Coverdale, C A; Lepell, P D; Shelton, K P; Safronova, A S; Kantsyrev, V L; Osborne, G; Sotnikov, V I; Ivanov, V V; Fedin, D; Nalajala, V; Yilmaz, F; Shrestha, I

    2008-03-14

    Axially localized NaF dopants are coated onto Al cylindrical wire arrays in order to act as spectroscopic tracers in the stagnated z-pinch plasma. Non-local-thermodynamic-equilibrium kinetic models fit to Na K-shell lines provide an independent measurement of the density and temperature that is consistent with spectroscopic analysis of K-shell emissions from Al and an alloyed Mg dopant. Axial transport of the Na dopant is observed, enabling quantitative study of instabilities in dense z-pinch plasmas. PMID:18352197

  15. A Validation of Eye Movements as a Measure of Elementary School Children's Developing Number Sense

    ERIC Educational Resources Information Center

    Schneider, Michael; Heine, Angela; Thaler, Verena; Torbeyns, Joke; De Smedt, Bert; Verschaffel, Lieven; Jacobs, Arthur M.; Stern, Elsbeth

    2008-01-01

    The number line estimation task captures central aspects of children's developing number sense, that is, their intuitions for numbers and their interrelations. Previous research used children's answer patterns and verbal reports as evidence of how they solve this task. In the present study we investigated to what extent eye movements recorded…

  16. Measurement of fracture aperture fields using transmitted light: An evaluation of measurement errors and their influence on simulations of flow and transport through a single fracture

    NASA Astrophysics Data System (ADS)

    Detwiler, Russell L.; Pringle, Scott E.; Glass, Robert J.

    1999-09-01

    Understanding of single-phase and multiphase flow and transport in fractures can be greatly enhanced through experimentation in transparent systems (analogs or replicas) where light transmission techniques yield quantitative measurements of aperture, solute concentration, and phase saturation fields. Here we quantify aperture field measurement error and demonstrate the influence of this error on the results of flow and transport simulations (hypothesized experimental results) through saturated and partially saturated fractures. We find that precision and accuracy can be balanced to greatly improve the technique and present a measurement protocol to obtain a minimum error field. Simulation results show an increased sensitivity to error as we move from flow to transport and from saturated to partially saturated conditions. Significant sensitivity under partially saturated conditions results in differences in channeling and multiple-peaked breakthrough curves. These results emphasize the critical importance of defining and minimizing error for studies of flow and transport in single fractures.

  17. Measurements of air pollution emission factors for marine transportation in SECA

    NASA Astrophysics Data System (ADS)

    Alföldy, B.; Lööv, J. B.; Lagler, F.; Mellqvist, J.; Berg, N.; Beecken, J.; Weststrate, H.; Duyzer, J.; Bencs, L.; Horemans, B.; Cavalli, F.; Putaud, J.-P.; Janssens-Maenhout, G.; Csordás, A. P.; Van Grieken, R.; Borowiak, A.; Hjorth, J.

    2013-07-01

    The chemical composition of the plumes of seagoing ships was measured during a two week long measurement campaign in the port of Rotterdam, Hoek van Holland The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg-1 fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg-1 fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factors. The intercept of the regression line, 4.8 × 1015 (kg fuel)-1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.

  18. Permalloy and Co50Pd50 as ferromagnetic contacts for magnetoresistance measurements in carbon nanotube-based transport structures

    NASA Astrophysics Data System (ADS)

    Morgan, Caitlin; Schneider, Claus M.; Meyer, Carola

    2012-04-01

    In this paper, magnetoresistance (MR) measurements on carbon nanotube (CNT) 2-terminal spin-valve devices are presented. Results from samples with both permalloy (Py) and CoPd contacts show repeatable MR switching. In performing gate-dependent MR measurements on the Py-contacted CNTs, two distinct transport regimes are identified, and their transport behavior is discussed with respect to optimizing MR. Results from the first CoPd-contacted CNTs indicate a stable magnetic response with a higher magnitude than that of a Py-contacted nanotube in the same transport regime.

  19. 41 CFR 102-118.170 - Will GSA continue to maintain a centralized numbering system for Government transportation...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...this system. Write to: General Services Administration Transportation Audit Division (QMCA) Crystal Plaza 4, Room 300 2200 Crystal Drive Arlington, VA 22202 www.gsa.gov/transaudits [65 FR 24569, Apr. 26, 2000,...

  20. 41 CFR 102-118.170 - Will GSA continue to maintain a centralized numbering system for Government transportation...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...this system. Write to: General Services Administration Transportation Audit Division (QMCA) Crystal Plaza 4, Room 300 2200 Crystal Drive Arlington, VA 22202 www.gsa.gov/transaudits [65 FR 24569, Apr. 26, 2000,...

  1. 41 CFR 102-118.170 - Will GSA continue to maintain a centralized numbering system for Government transportation...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...this system. Write to: General Services Administration Transportation Audit Division (QMCA) Crystal Plaza 4, Room 300 2200 Crystal Drive Arlington, VA 22202 www.gsa.gov/transaudits [65 FR 24569, Apr. 26, 2000,...

  2. 41 CFR 102-118.170 - Will GSA continue to maintain a centralized numbering system for Government transportation...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...this system. Write to: General Services Administration Transportation Audit Division (QMCA) Crystal Plaza 4, Room 300 2200 Crystal Drive Arlington, VA 22202 www.gsa.gov/transaudits [65 FR 24569, Apr. 26, 2000,...

  3. 41 CFR 102-118.170 - Will GSA continue to maintain a centralized numbering system for Government transportation...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...this system. Write to: General Services Administration Transportation Audit Division (QMCA) Crystal Plaza 4, Room 300 2200 Crystal Drive Arlington, VA 22202 www.gsa.gov/transaudits [65 FR 24569, Apr. 26, 2000,...

  4. Analysis of Fluctuating Static Pressure Measurements in a Large High Reynolds Number Transonic Cryogenic Wind Tunnel. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Igoe, William B.

    1991-01-01

    Dynamic measurements of fluctuating static pressure levels were made using flush mounted high frequency response pressure transducers at eleven locations in the circuit of the National Transonic Facility (NTF) over the complete operating range of this wind tunnel. Measurements were made at test section Mach numbers from 0.2 to 1.2, at pressure from 1 to 8.6 atmospheres and at temperatures from ambient to -250 F, resulting in dynamic flow disturbance measurements at the highest Reynolds numbers available in a transonic ground test facility. Tests were also made independently at variable Mach number, variable Reynolds number, and variable drivepower, each time keeping the other two variables constant thus allowing for the first time, a distinct separation of these three important variables. A description of the NTF emphasizing its flow quality features, details on the calibration of the instrumentation, results of measurements with the test section slots covered, downstream choke, effects of liquid nitrogen injection and gaseous nitrogen venting, comparisons between air and nitrogen, isolation of the effects of Mach number, Reynolds number, and fan drive power, and identification of the sources of significant flow disturbances is included. The results indicate that primary sources of flow disturbance in the NTF may be edge-tones generated by test section sidewall re-entry flaps and the venting of nitrogen gas from the return leg of the tunnel circuit between turns 3 and 4 in the cryogenic mode of operation. The tests to isolate the effects of Mach number, Reynolds number, and drive power indicate that Mach number effects predominate. A comparison with other transonic wind tunnels shows that the NTF has low levels of test section fluctuating static pressure especially in the high subsonic Mach number range from 0.7 to 0.9.

  5. Identifying fire plumes in the Arctic with tropospheric FTIR measurements and transport models

    NASA Astrophysics Data System (ADS)

    Viatte, C.; Strong, K.; Hannigan, J.; Nussbaumer, E.; Emmons, L.; Conway, S.; Paton-Walsh, C.; Hartley, J.; Benmergui, J.; Lin, J.

    2014-10-01

    We investigate Arctic tropospheric composition using ground-based Fourier Transform Infrared (FTIR) solar absorption spectra, recorded at the Polar Environment Atmospheric Research Laboratory (PEARL, Eureka, Nunavut, Canada, 80°5' N, 86°42' W) and at Thule (Greenland, 76°53' N, -68°74' W) from 2008 to 2012. The target species: carbon monoxide (CO), hydrogen cyanide (HCN), ethane (C2H6), acetylene (C2H2), formic acid (HCOOH), and formaldehyde (H2CO) are emitted by biomass burning and can be transported from mid-latitudes to the Arctic. By detecting simultaneous enhancements of three biomass burning tracers (HCN, CO, and C2H6), ten and eight fire events are identified at Eureka and Thule, respectively, within the five-year FTIR timeseries. Analyses of Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) back-trajectories coupled with Moderate Resolution Imaging Spectroradiometer (MODIS) fire hot spot data, Stochastic Time-Inverted Lagrangian Transport model (STILT) footprints, and Ozone Monitoring Instrument (OMI) UV aerosol index maps are used to attribute burning source regions and travel time durations of the plumes. By taking into account the effect of aging of the smoke plumes, measured FTIR enhancement ratios were corrected to obtain emission ratios and equivalent emission factors. The means of emission factors for extratropical forest estimated with the two FTIR datasets are 0.39 ± 0.15 g kg-1 for HCN, 1.23 ± 0.49 g kg-1 for C2H6, 0.34 ± 0.16 g kg-1 for C2H2, 2.13 ± 0.92 g kg-1 for HCOOH, and 3.14 ± 1.28 g kg-1 for CH3OH. To improve our knowledge concerning the dynamical and chemical processes associated with Arctic pollution from fires, the two sets of FTIR measurements were compared to the Model for Ozone and Related chemical Tracers, version 4 (MOZART-4). Seasonal cycles and day-to-day variabilities were compared to assess the ability of the model to reproduce emissions from fires and their transport. Good agreement in winter confirms that transport is well implemented in the model. For C2H6, however, the lower wintertime concentration estimated by the model as compared to the FTIR observations highlight an underestimation of its emission. Results show that modelled and measured total columns are correlated (linear correlation coefficient r > 0.6 for all gases except for H2CO at Eureka and HCOOH at Thule), but suggest a~general underestimation of the concentrations in the model for all seven tropospheric species in the high Arctic.

  6. Identifying fire plumes in the Arctic with tropospheric FTIR measurements and transport models

    NASA Astrophysics Data System (ADS)

    Viatte, C.; Strong, K.; Hannigan, J.; Nussbaumer, E.; Emmons, L. K.; Conway, S.; Paton-Walsh, C.; Hartley, J.; Benmergui, J.; Lin, J.

    2015-03-01

    We investigate Arctic tropospheric composition using ground-based Fourier transform infrared (FTIR) solar absorption spectra, recorded at the Polar Environment Atmospheric Research Laboratory (PEARL, Eureka, Nunavut, Canada, 80°05' N, 86°42' W) and at Thule (Greenland, 76°53' N, -68°74' W) from 2008 to 2012. The target species, carbon monoxide (CO), hydrogen cyanide (HCN), ethane (C2H6), acetylene (C2H2), formic acid (HCOOH), and formaldehyde (H2CO) are emitted by biomass burning and can be transported from mid-latitudes to the Arctic. By detecting simultaneous enhancements of three biomass burning tracers (HCN, CO, and C2H6), ten and eight fire events are identified at Eureka and Thule, respectively, within the 5-year FTIR time series. Analyses of Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model back-trajectories coupled with Moderate Resolution Imaging Spectroradiometer (MODIS) fire hotspot data, Stochastic Time-Inverted Lagrangian Transport (STILT) model footprints, and Ozone Monitoring Instrument (OMI) UV aerosol index maps, are used to attribute burning source regions and travel time durations of the plumes. By taking into account the effect of aging of the smoke plumes, measured FTIR enhancement ratios were corrected to obtain emission ratios and equivalent emission factors. The means of emission factors for extratropical forest estimated with the two FTIR data sets are 0.40 ± 0.21 g kg-1 for HCN, 1.24 ± 0.71 g kg-1 for C2H6, 0.34 ± 0.21 g kg-1 for C2H2, and 2.92 ± 1.30 g kg-1 for HCOOH. The emission factor for CH3OH estimated at Eureka is 3.44 ± 1.68 g kg-1. To improve our knowledge concerning the dynamical and chemical processes associated with Arctic pollution from fires, the two sets of FTIR measurements were compared to the Model for OZone And Related chemical Tracers, version 4 (MOZART-4). Seasonal cycles and day-to-day variabilities were compared to assess the ability of the model to reproduce emissions from fires and their transport. Good agreement in winter confirms that transport is well implemented in the model. For C2H6, however, the lower wintertime concentration estimated by the model as compared to the FTIR observations highlights an underestimation of its emission. Results show that modeled and measured total columns are correlated (linear correlation coefficient r > 0.6 for all gases except for H2CO at Eureka and HCOOH at Thule), but suggest a general underestimation of the concentrations in the model for all seven tropospheric species in the high Arctic.

  7. Measurements of the number density of water molecules in plasma by using a combined spectral-probe method

    NASA Astrophysics Data System (ADS)

    Bernatskiy, A. V.; Ochkin, V. N.; Afonin, O. N.; Antipenkov, A. B.

    2015-09-01

    A novel method for measuring the number density of water molecules in low-temperature plasma is developed. The absolute intensities of rotational lines of the (0,0) band of the OH( A 2?- X 2?) transition are used. Lines with sufficiently large rotational quantum numbers referring to the so-called "hot" group of molecules produced by electron-impact dissociative excitation of water molecules are chosen for measurements. The excitation rate of a process with a known cross section is determined by measuring the parameters of plasma electrons by means of the probe method. The measured number densities of molecules are compared with those in the initial plasma-forming mixture. The time evolution of the particle densities in plasma is investigated. The problems of the sensitivity and applicability of the absolute spectral method are considered.

  8. Measurement of the Critical Deposition Velocity in Slurry Transport through a Horizontal Pipe

    SciTech Connect

    Erian, Fadel F.; Furfari, Daniel J.; Kellogg, Michael I.; Park, Walter R.

    2001-03-01

    Critical Deposition Velocity (CDV) is an important design and operational parameter in slurry transport. Almost all existing correlations that are used to predict this parameter have been obtained experimentally from slurry transport tests featuring single solid species in the slurry mixture. No correlations have been obtained to describe this parameter when the slurry mixture contains more than one solid species having a wide range of specific gravities, particle size distributions, and volume concentrations within the overall slurry mixture. There are no physical or empirical bases that can justify the extrapolation or modification of the existing single species correlations to include all these effects. New experiments must be carried out to obtain new correlations that would be suited for these types of slurries, and that would clarify the mechanics of solids deposition as a function of the properties of the various solid species. Our goal in this paper is to describe a robust experimental technique for the accurate determination of the critical deposition velocity associated with the transport of slurries in horizontal or slightly inclined pipes. Because of the relative difficulty encountered during the precise determination of this useful operational parameter, it has been the practice to connect it with some transitional behavior of more easily measurable flow parameters such as the pressure drop along the slurry pipeline. In doing so, the critical deposition velocity loses its unique and precise definition due to the multitude of factors that influence such transitional behaviors. Here, data has been obtained for single species slurries made up of washed garnet and water and flowing through a 1- inch clear pipe. The selected garnet had a narrow particle size distribution with a mean diameter of 100 mm, approximately. The critical deposition velocity was measured for garnet/water slurries of 10, 20, and 30 percent solids concentration by volume.

  9. Measurements of radial profiles of He sup 2+ transport coefficients on TFTR (Tokamak Fusion Test Reactor)

    SciTech Connect

    Synakowski, E.J.; Stratton, B.C.; Efthimion, P.C.; Hulse, R.A.; Johnson, D.W.; Mansfield, D.K.; Park, H.; Scott, S.D.; Taylor, G. . Plasma Physics Lab.); Fonck, R.J. . Dept. of Nuclear Engineering and Engineering Physics)

    1990-06-01

    Measurements of the spatial structure of the transport coefficients of He{sup 2+} on the Tokamak Fusion Test Reactor is reported. He{sup 2+} profiles were measured using charge exchange spectroscopy after a helium puff into corotating L-mode plasmas. Modelling shows that the He{sup 2+} diffusivity is about 10 m{sup 2}/s near the plasma edge and drops to below 1 m{sup 2}/s inside of the q = 1 surface. The convective velocity ranges from 1--3 m/s near q = 1 to 20--40 m/s near the edge. The helium diffusivity is on the order of the ion momentum and thermal diffusivity and is greater that than the electron thermal diffusivity. 4 refs., 4 figs.

  10. Parallel measurement of conductive and convective thermal transport of micro/nanowires based on Raman mapping

    NASA Astrophysics Data System (ADS)

    Li, Man; Li, Changzheng; Wang, Jianmei; Xiao, Xiangheng; Yue, Yanan

    2015-06-01

    Heat conduction and convection are coupled effects in thermal transport of low-dimensional materials especially at micro/nanoscale. However, the parallel measurement is a challenge due to the limitation of characterization pathways. In this work, we report a method to study conductive and convective thermal transport of micro/nanowires simultaneously by using steady-state Joule-heating and Raman mapping. To examine this method, the carbon nanotubes (CNTs) fiber (36 ?m in diameter) is characterized and its temperature dependence of thermal properties including thermal conductivity and convection coefficient in ambient air is studied. Preliminary results show that thermal conductivity of the CNTs fiber increases from 26 W/m K to 34 W/m K and convection coefficient decreases from 1143 W/m2 K to 1039 W/m2 K with temperature ranging from 312 to 444 K. The convective heat dissipation to the air could be as high as 60% of the total Joule heating power. Uncertainty analysis is performed to reveal that fitting errors can be further reduced by increasing sampling points along the fiber. This method features a fast/convenient way for parallel measurement of both heat conduction and convection of micro/nanowires which is beneficial to comprehensively understanding the coupled effect of micro/nanoscale heat conduction and convection.

  11. SO2 measurements at a high altitude site in the central Himalayas: Role of regional transport

    NASA Astrophysics Data System (ADS)

    Naja, Manish; Mallik, Chinmay; Sarangi, Tapaswini; Sheel, Varun; Lal, Shyam

    2014-12-01

    Continuous measurements of a climatically important acidic gas, SO2, were made over Nainital (29.37°N, 79.45°E; 1958 m amsl), a regionally representative site in the central Himalayas, for the first time during 2009-2011. Unlike many other sites, the SO2 levels over Nainital are higher during pre-monsoon (345 pptv) compared to winter (71 pptv). High values during pre-monsoon are attributed to the transport of air masses from regions viz. Indo-Gangetic Plain (IGP), northern India and north-East Pakistan, which are dotted with numerous industries and power plants, where coal burning occurs. Transport from the polluted regions is evinced from good correlations of SO2 with wind speed, NOy and UV aerosol index during these periods. Daytime elevations in SO2 levels, influenced by 'valley winds' and boundary layer evolution, is a persistent feature at Nainital. SO2 levels are very much lower during monsoon compared to pre-monsoon, due to oxidation losses and wet scavenging. Despite this, SO2/NOy slopes are high (>0.4) both during pre-monsoon and monsoon, indicating impacts of point sources. The SO2 levels during winter are lower as the measurement site is cut off from the plains due to boundary layer dynamics. Further, the SO2 levels during winter nights are the lowest (lesser than 50 pptv) and resemble free tropospheric conditions.

  12. Volume transport and mixing of the Faroe Bank Channel overflow from one year of moored measurements

    NASA Astrophysics Data System (ADS)

    Ullgren, J. E.; Darelius, E.; Fer, I.

    2015-10-01

    One-year long time series of current velocity and temperature from ten moorings deployed in the Faroe Bank Channel (FBC) are analysed to describe the structure and variability of the dense overflow plume on daily to seasonal time scales. Mooring arrays are deployed in two sections: located 25 km downstream of the main sill, in the channel that geographically confines the overflow plume at both edges (section C), and 60 km further downstream, over the slope (section S). At section C, the average volume transport of overflow waters (< 3 °C) from the Nordic Seas towards the Iceland Basin is 1.3 ± 0.3 Sv; at Section S, transport of modified overflow water (< 6 °C) is 1.8 ± 0.7 Sv. The volume transport through the slope section is dominated by mesoscale variability at 3-5 day time scale. A simplified view of along-path entrainment of a gravity current is not accurate for the FBC overflow. As the plume proceeds into the stratified ambient water, there is substantial detrainment from the deeper layer (bounded by the 3 °C isotherm), of comparable magnitude to the entrainment into the interfacial layer (between the 3 and 6 °C isotherms). Time series of gradient Richardson number suggests a quiescent plume core capped by turbulent near bottom and interfacial layers in the channel. At section S, in contrast, the entire overflow plume is turbulent. Based on a two-layer heat budget constructed for the overflow, mean diffusivities across the top of the bottom layer, and across the interfacial layer are (30 ± 15) × 10-4 m2 s-1 and (119 ± 43) × 10-4 m2 s-1, respectively.

  13. Stability and performance characteristics of a fixed arrow wing supersonic transport configuration (SCAT 15F-9898) at Mach numbers from 0.60 to 1.20

    NASA Technical Reports Server (NTRS)

    Decker, J. P.; Jacobs, P. F.

    1978-01-01

    Tests on a 0.015 scale model of a supersonic transport were conducted at Mach numbers from 0.60 to 1.20. Tests of the complete model with three wing planforms, two different leading-edge radii, and various combinations of component parts, including both leading- and trailing-edge flaps, were made over an angle-of-attack range from about -6 deg to 13 deg and at sideslip angles of 0 deg and 2 deg.

  14. Quantitative measurements and modeling of cargo-motor interactions during fast transport in the living axon

    NASA Astrophysics Data System (ADS)

    Seamster, Pamela E.; Loewenberg, Michael; Pascal, Jennifer; Chauviere, Arnaud; Gonzales, Aaron; Cristini, Vittorio; Bearer, Elaine L.

    2012-10-01

    The kinesins have long been known to drive microtubule-based transport of sub-cellular components, yet the mechanisms of their attachment to cargo remain a mystery. Several different cargo-receptors have been proposed based on their in vitro binding affinities to kinesin-1. Only two of these—phosphatidyl inositol, a negatively charged lipid, and the carboxyl terminus of the amyloid precursor protein (APP-C), a trans-membrane protein—have been reported to mediate motility in living systems. A major question is how these many different cargo, receptors and motors interact to produce the complex choreography of vesicular transport within living cells. Here we describe an experimental assay that identifies cargo-motor receptors by their ability to recruit active motors and drive transport of exogenous cargo towards the synapse in living axons. Cargo is engineered by derivatizing the surface of polystyrene fluorescent nanospheres (100 nm diameter) with charged residues or with synthetic peptides derived from candidate motor receptor proteins, all designed to display a terminal COOH group. After injection into the squid giant axon, particle movements are imaged by laser-scanning confocal time-lapse microscopy. In this report we compare the motility of negatively charged beads with APP-C beads in the presence of glycine-conjugated non-motile beads using new strategies to measure bead movements. The ensuing quantitative analysis of time-lapse digital sequences reveals detailed information about bead movements: instantaneous and maximum velocities, run lengths, pause frequencies and pause durations. These measurements provide parameters for a mathematical model that predicts the spatiotemporal evolution of distribution of the two different types of bead cargo in the axon. The results reveal that negatively charged beads differ from APP-C beads in velocity and dispersion, and predict that at long time points APP-C will achieve greater progress towards the presynaptic terminal. The significance of this data and accompanying model pertains to the role transport plays in neuronal function, connectivity, and survival, and has implications in the pathogenesis of neurological disorders, such as Alzheimer’s, Huntington and Parkinson's diseases.

  15. Quantitative measurements and modeling of cargo–motor interactions during fast transport in the living axon

    PubMed Central

    Seamster, Pamela E; Loewenberg, Michael; Pascal, Jennifer; Chauviere, Arnaud; Gonzales, Aaron; Cristini, Vittorio; Bearer, Elaine L

    2013-01-01

    The kinesins have long been known to drive microtubule-based transport of sub-cellular components, yet the mechanisms of their attachment to cargo remain a mystery. Several different cargo-receptors have been proposed based on their in vitro binding affinities to kinesin-1. Only two of these—phosphatidyl inositol, a negatively charged lipid, and the carboxyl terminus of the amyloid precursor protein (APP-C), a trans-membrane protein—have been reported to mediate motility in living systems. A major question is how these many different cargo, receptors and motors interact to produce the complex choreography of vesicular transport within living cells. Here we describe an experimental assay that identifies cargo–motor receptors by their ability to recruit active motors and drive transport of exogenous cargo towards the synapse in living axons. Cargo is engineered by derivatizing the surface of polystyrene fluorescent nanospheres (100 nm diameter) with charged residues or with synthetic peptides derived from candidate motor receptor proteins, all designed to display a terminal COOH group. After injection into the squid giant axon, particle movements are imaged by laser-scanning confocal time-lapse microscopy. In this report we compare the motility of negatively charged beads with APP-C beads in the presence of glycine-conjugated non-motile beads using new strategies to measure bead movements. The ensuing quantitative analysis of time-lapse digital sequences reveals detailed information about bead movements: instantaneous and maximum velocities, run lengths, pause frequencies and pause durations. These measurements provide parameters for a mathematical model that predicts the spatiotemporal evolution of distribution of the two different types of bead cargo in the axon. The results reveal that negatively charged beads differ from APP-C beads in velocity and dispersion, and predict that at long time points APP-C will achieve greater progress towards the presynaptic terminal. The significance of this data and accompanying model pertains to the role transport plays in neuronal function, connectivity, and survival, and has implications in the pathogenesis of neurological disorders, such as Alzheimer’s, Huntington and Parkinson’s diseases. PMID:23011729

  16. Measurement of water transport during freezing in cell suspensions using a differential scanning calorimeter.

    PubMed

    Devireddy, R V; Raha, D; Bischof, J C

    1998-03-01

    A new technique using a differential scanning calorimeter (DSC) was developed to obtain dynamic and quantitative water transport data in cell suspensions during freezing. The model system investigated was a nonattached spherical lymphocyte (Epstein-Barr virus transformed, EBVT) human cell line. Data from the technique show that the initial heat release of a prenucleated sample containing osmotically active cells in media is greater than the final heat release of an identical sample of osmotically inactive or lysed cells in media. The total integrated magnitude of this difference, Deltaqdsc, was found to be proportional to the cytocrit and hence also to the supercooled water volume in the sample. Further, the normalized fractional integrated heat release difference as a function of temperature, Deltaq(T)dsc/Deltaqdsc, was shown to correlate with the amount of supercooled cellular water which had exosmosed from the cell as a function of subzero temperature at constant cooling rates of 5, 10, and 20 degrees C/min. Several important limitations of the technique are (1) that it requires a priori knowledge of geometric parameters such as the surface area, initial volume, and osmotically inactive cell volume and (2) that the technique alone cannot determine whether the heat released from supercooled cellular water is due to dehydration or intracellular ice formation. Cryomicroscopy was used to address these limitations. The initial cell volume and surface area were obtained directly whereas a Boyle-van't Hoff (BVH) plot was constructed to obtain the osmotically inactive cell volume Vb. Curve fitting the BVH data assuming linear osmometric behavior yielded Vb = 0.258V0; however, nonlinearity in the data suggests that the EBVT lymphocyte cells are not "ideal osmometers" at low subzero temperatures and created some uncertainty in the actual value of Vb. Cryomicroscopy further confirmed that dehydration was the predominant biophysical response of the cells over the range of cooling rates investigated. One notable exception occurred at a rate of 20 degrees C/min where evidence for intracellular ice formation due to a DSC measured heat release between -30 and -34 degrees C correlated with a higher end volume but no darkening of the cells during cryomicroscopy. For the cooling rate tested (5 degrees C/min) the cryomicroscopy data correlated statistically very well with the DSC water transport data. A model of water transport was fit to the DSC water transport data and the average (5, 10, and 20 degrees C/min) biophysical parameters for the EBVT lymphocytes were found to be Lpg = 0.10 micro m/min-atm, ELp = 15.5 kcal/mol. Finally, the decrease in heat release from osmotically active cells measured by the DSC during repetitive freezing and thawing was found to correlate strongly with the viability of the cells measured during identical freeze/thaw protocols with cryomicroscopy. This shows the additional ability of the technique to assess freeze/thaw injury. In summary, this DSC technique is a promising new approach for measuring water transport in cellular systems during freezing. PMID:9527874

  17. Fluorescence measurements of anion transport by the GABA receptor in reconstituted membrane preparations

    SciTech Connect

    Dunn, S.M.J.; Shelman, R.A.; Agey, M.W. )

    1989-03-21

    A fluorescence assay for measuring the functional properties of the GABA{sub A} receptor in reconstituted membrane vesicles is described. This assay is based on a method previously described to measure monovalent cation transport mediated by the nicotinic acetylcholine receptor in membranes from Torpedo electric organ. The GABA{sub A} receptor has been solubilized from bovine brain membranes and reconstituted into phospholipid vesicles. Influx of chloride or iodide into the vesicles has been measured in stopped-flow experiments by monitoring the fluorescence quench of an anion-sensitive fluorophore trapped within the vesicles. Muscimol, a GABA{sub A} receptor agonist, stimulated a rapid uptake of either chloride or iodide. Stimulation of chloride influx was dependent on the concentration of muscimol, and the midpoint of the dose-response curve occurred at approximately 0.3 {mu}M. Agonist-stimulated uptake was enhanced by diazepam and blocked by desensitization and by the antagonists bicuculline and picrotoxin. These receptor-mediated effects are shown to be qualitatively similar to measurements of {sup 36}Cl{sup {minus}} and {sup 125}I{sup {minus}} efflux using synaptoneurosomes prepared from rat cerebral cortex. The advantages of the fluorescence method in terms of its improved time resolution, sensitivity, and suitability for quantitating GABA{sub A} receptor function are discussed.

  18. Mesoscale Backtracking by Means of Atmospheric Transport Modeling of Xenon Plumes Measured by Radionuclide Gas Stations

    NASA Astrophysics Data System (ADS)

    Armand, P. P.; Achim, P.; Taffary, T.

    2006-12-01

    The monitoring of atmospheric radioactive xenon concentration is performed for nuclear safety regulatory requirements. It is also planned to be used for the detection of hypothetical nuclear tests in the framework of the Comprehensive nuclear-Test-Ban Treaty (CTBT). In this context, the French Atomic Energy Commission designed a high sensitive and automated fieldable station, named SPALAX, to measure the activity concentrations of xenon isotopes in the atmosphere. SPALAX stations were set up in Western Europe and have been operated quite continuously for three years or more, detecting principally xenon-133 and more scarcely xenon-135, xenon-133m and xenon-131m. There are around 150 nuclear power plants in the European Union, research reactors, reprocessing plants, medical production and application facilities releasing radioactive xenon in normal or incidental operations. A numerical study was carried out aiming to explain the SPALAX measurements. The mesoscale Atmospheric Transport Modelling involves the MM5 suite (PSU- NCAR) to predict the wind fields on nested domains, and FLEXPART, a 3D Lagrangian particle dispersion code, used to simulate the backward transport of xenon plumes detected by the SPALAX. For every event of detection, at least one potential xenon source has a significant efficiency of emission. The identified likely sources are located quite close to the SPALAX stations (some tens of kilometres), or situated farther (a few hundreds of kilometres). A base line of some mBq per cubic meter in xenon-133 is generated by the nuclear power plants. Peaks of xenon-133 ranging from tens to hundreds of mBq per cubic meter originate from a radioisotope production facility. The calculated xenon source terms required to obtain the SPALAX measurements are discussed and seem consistent with realistic emissions from the xenon sources in Western Europe.

  19. Laboratory Measurements of Fluid Transport Properties on Tight Gas Sandstones and Applications

    NASA Astrophysics Data System (ADS)

    Albrecht, Daniel; Reitenbach, Viktor

    2014-05-01

    Deep gas reservoirs are of great interest for the E&P industry. Large areas of such reservoirs have permeabilities below 1 mD. The reservoir rocks in these areas show a strong stress sensitivity of the fluid transport properties and a considerable productivity decline due to changing stress conditions during the production process. For correct modeling and simulation of Tight Gas reservoirs it is important to know the behavior of the fluid transport properties under the changing stress condition the reservoir experiences. In several measurement series the effects of changing overburden and pore pressure on Rotliegend sandstone samples from north German Tight Gas reservoirs have been quantified and used to set up correlation functions. With the correlation functions from the own measurements and additional data and correlations from literature a Rock Data Catalog has been developed as tool to help reservoir engineers with modeling and simulation of such reservoirs. The Rock Data Catalog consists of the Rock Database and the Correlation Module. The Rock Database contains general and petrophysical rock data. The Correlation Module uses this data to generate secondary data of e.g. in-situ capillary and hydraulic rock properties with appropriate correlation functions. Viability of the economic gas production from Tight Gas Reservoirs strongly depends on reservoir quality. Therefore identification of high quality reservoir parts or so called Sweet Spots for placing production wells and planning hydraulic fracturing stimulation, is one of key issues of the tight gas reservoir characterization and evaluation. The data and correlation functions collected in the Rock Data Catalog could also be used to identify Sweet Spots in Tight Gas reservoirs. Several rock parameters and properties, which affect the fluid flow in a reservoir (like lithology, clay content, water saturation, permeability, pore size distribution) can be identified and used to set up a Sweet Spot Index as a measure for the reservoir quality.

  20. Measuring Relevant Properties of Cohesive Sediment Aggregates ("Flocks") for Sediment Transport Modeling

    NASA Astrophysics Data System (ADS)

    Reed, A. H.; Zhang, G.; Tan, X.; Yin, H.; Furukawa, Y.

    2012-12-01

    Improvements to nearshore sediment transport models require increased fidelity and new data on the strength, density, structure and size of cohesive sediment aggregates or "flocs". To facilitate this, we developed new methods to evaluate flocculated sediments and the results that were generated facilitate improved numerical simulations of suspended and bedload sediment transport. Typically, flocs originate as aggregated clumps of clays and organic matter (e.g., biopolymers, humic acids) that chemically bond when they enter saline water, such that the floc particle grows in size until it is often orders of magnitude larger than the constituent particles. This important factor yields settling velocities for flocs that are orders of magnitude faster than that of the primary particles. Our recent work has compared the relationship of biopolymer-clay and clay-clay flocs in laboratory experiments that were conducted on synthetic (i.e., produced in the lab) and natural flocs (i.e., gathered from coastal estuaries). The size, shape and density of flocs directly impact transport properties such as hydrodynamic drag, hindered settling velocity and density, which are further altered by floc compressive and shear strength. Due to an inability to measure these transport and strength properties in situ on individual flocs, settling velocity of individual flocs has often been related to the fractal dimensionality, which is an indication of floc porosity, density and strength. Therefore, this work has correlated settling velocity with fractal dimensionality for both types of flocs in initial studies. Then in order to address the influence of flow velocity and fluid shear stress on floc shape and size, both floc types were entrained in a flow-through particle size analyzer to establish correlations between turbulent flow velocity and floc size modality. The compressive strength of these flocs was addressed directly by subjecting them to high-resolution (50 nN sensitivity) compression tests that provides a determination of the elastic modulus and yield shear strength. These data are requisite components of a sediment transport model that uses the discrete element method (DEM) to determine how particles respond to particle collisions within the water column. To address the influence consolidation of flocs that were deposited on the seafloor, a micro/nano-cone penetrometer was developed. This test uses a mm-sized cone that is coupled to a high-resolution load cell so that the strength of the top few mm of the newly formed seabed can be characterized in terms of bearing capacity and undrained shear strength. This data will be used to drive numerical simulations of cohesive bedload entrainment, transport and resuspension. Ultimately, these assessments will provide realistic and useful data to facilitate and improve various modeling efforts, which simulate and predict suspended sediment and bedload transport in estuarine and nearshore coastal environments where cohesive sediments abound.

  1. An Analysis and Review of Measures and Relationships in Space Transportation Affordability

    NASA Technical Reports Server (NTRS)

    Zapata, Edgar; McCleskey, Carey

    2014-01-01

    The affordability of transportation to or from space is of continued interest across numerous and diverse stakeholders in our aerospace industry. Such an important metric as affordability deserves a clear understanding among stakeholders about what is meant by affordability, costs, and related terms, as otherwise it's difficult to see where specific improvements are needed or where to target specific investments. As captured in the famous words of Lewis Carroll, "If you don't know where you are going, any road will get you there". As important as understanding a metric may be, with terms such as costs, prices, specific costs, average costs, marginal costs, etc., it is equally important to understand the relationship among these measures. In turn, these measures intermingle with caveats and factors that introduce more measures in need of a common understanding among stakeholders. These factors include flight rates, capability, and payload. This paper seeks to review the costs of space transportation systems and the relationships among the many factors involved in costs from the points of view of diverse decision makers. A decision maker may have an interest in acquiring a single launch considering the best price (along with other factors in their business case), or an interest in many launches over time. Alternately, a decision maker may have a specific interest in developing a space transportation system that will offer certain prices, or flight rate capability, or both, at a certain up-front cost. The question arises for the later, to reuse or to expend? As it is necessary in thinking about the future to clearly understand the past and the present, this paper will present data and graphics to assist stakeholders in visualizing trends and the current state of affairs in the launch industry. At all times, raw data will be referenced (or made available separately) alongside detailed explanations about the data, so as to avoid the confusion or misleading conclusions that occur more often than not with complex graphs or statements when such context is lacking.

  2. GIS measured environmental correlates of active school transport: A systematic review of 14 studies

    PubMed Central

    2011-01-01

    Background Emerging frameworks to examine active school transportation (AST) commonly emphasize the built environment (BE) as having an influence on travel mode decisions. Objective measures of BE attributes have been recommended for advancing knowledge about the influence of the BE on school travel mode choice. An updated systematic review on the relationships between GIS-measured BE attributes and AST is required to inform future research in this area. The objectives of this review are: i) to examine and summarize the relationships between objectively measured BE features and AST in children and adolescents and ii) to critically discuss GIS methodologies used in this context. Methods Six electronic databases, and websites were systematically searched, and reference lists were searched and screened to identify studies examining AST in students aged five to 18 and reporting GIS as an environmental measurement tool. Fourteen cross-sectional studies were identified. The analyses were classified in terms of density, diversity, and design and further differentiated by the measures used or environmental condition examined. Results Only distance was consistently found to be negatively associated with AST. Consistent findings of positive or negative associations were not found for land use mix, residential density, and intersection density. Potential modifiers of any relationship between these attributes and AST included age, school travel mode, route direction (e.g., to/from school), and trip-end (home or school). Methodological limitations included inconsistencies in geocoding, selection of study sites, buffer methods and the shape of zones (Modifiable Areal Unit Problem [MAUP]), the quality of road and pedestrian infrastructure data, and school route estimation. Conclusions The inconsistent use of spatial concepts limits the ability to draw conclusions about the relationship between objectively measured environmental attributes and AST. Future research should explore standardizing buffer size, assess the quality of street network datasets and, if necessary, customize existing datasets, and explore further attributes linked to safety. PMID:21545750

  3. Measurement of resistance to solute transport across surfactant-laden interfaces using a Fluorescence Recovery After Photobleaching (FRAP) technique

    NASA Technical Reports Server (NTRS)

    Browne, Edward P.; Nivaggioli, Thierry; Hatton, T. Alan

    1994-01-01

    A noninvasive fluorescence recovery after photobleaching (FRAP) technique is under development to measure interfacial transport in two phase systems without disturbing the interface. The concentration profiles of a probe solute are measured in both sides of the interface by argon-ion laser, and the system relaxation is then monitored by a microscope-mounted CCD camera.

  4. Spray washing, absorbent corn starch powder and dry time to reduce bacterial numbers on soiled boiler transport cage flooring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most broilers in the U.S. are transported live to slaughter facilities in cages with fiberglass floors. Cages are often used repeatedly without washing and fecal matter deposited on the floor surface can transfer Campylobacter from one flock to another. Drying feces out between uses is an effectiv...

  5. An increasing number of synthetic compounds have been shown to facilitate ion and polar molecule transport across

    E-print Network

    Smith, Bradley D.

    amino acid sequences to transport peptides and proteins across cellular membranes. Addresses Department Science Ltd. All rights reserved. Published online 18 October 2002 Abbreviations PC phosphatidylcholine PE naturally occurring channel-forming proteins or carrier molecules. The resultant compounds may utilize

  6. Extending the Capabilities of Single Particle Mass Spectrometry: I. Measurements of Aerosol Number Concentration, Size Distribution, and Asphericity

    SciTech Connect

    Vaden, Timothy D.; Imre, D.; Beranek, Josef; Zelenyuk, Alla

    2011-01-04

    Single particle mass spectrometers have traditionally been deployed to measure the size and composition of individual particles at relatively slow sampling rates that are determined by the rate at which the ionization lasers can fire and/or mass spectra can be recorded. To take advantage of the fact that under most conditions SPLAT can detect and size particles at much higher rates we developed a dual data acquisition mode, in which particle number concentrations, size distributions, and asphericity parameters are measured at a particle concentration determined rate, all the while the instrument generates and records mass-spectra at an operator set rate. We show that with this approach particle number concentration and asphericity parameters are measured with 1 sec resolution and particle vacuum aerodynamic size distributions are measured with 10 sec to 60 sec resolution. SPLAT measured particle number concentrations are in perfect agreement with the PCASP. Particle asphericity parameters are based on measured particle beam divergence. We illustrate the effect that high particle concentrations can have on the measured size distributions and develop a method to remove these effects and correct the size distributions.

  7. Evaluation and modeling of the size fractionated aerosol particle number concentration measurements nearby a major road in Helsinki - Part II: Aerosol measurements within the SAPPHIRE project

    NASA Astrophysics Data System (ADS)

    Hussein, T.; Kukkonen, J.; Korhonen, H.; Pohjola, M.; Pirjola, L.; Wraith, D.; Härkönen, J.; Teinilä, K.; Koponen, I. K.; Karppinen, A.; Hillamo, R.; Kulmala, M.

    2007-08-01

    This study presents an evaluation and modeling exercise of the size fractionated aerosol particle number concentrations measured nearby a major road in Helsinki during 23 August-19 September 2003 and 14 January-11 February 2004. The available information also included electronic traffic counts, on-site meteorological measurements, and urban background particle number size distribution measurement. The ultrafine particle (UFP, diameter<100 nm) number concentrations at the roadside site were approximately an order of magnitude higher than those at the urban background site during daytime and downwind conditions. Both the modal structure analysis of the particle number size distributions and the statistical correlation between the traffic density and the UFP number concentrations indicate that the UFP were evidently from traffic related emissions. The modeling exercise included the evolution of the particle number size distribution nearby the road during downwind conditions. The model simulation results revealed that the evaluation of the emission factors of aerosol particles might not be valid for the same site during different time.

  8. Measurement of quasi-ballistic heat transport across nanoscale interfaces using ultrafast coherent soft x-ray beams

    SciTech Connect

    Siemens, M.; Li, Q.; Yang, R.; Nelson, K.; Anderson, E.; Murnane, M.; Kapteyn, H.

    2009-03-02

    Understanding heat transport on nanoscale dimensions is important for fundamental advances in nanoscience, as well as for practical applications such as thermal management in nano-electronics, thermoelectric devices, photovoltaics, nanomanufacturing, as well as nanoparticle thermal therapy. Here we report the first time-resolved measurements of heat transport across nanostructured interfaces. We observe the transition from a diffusive to a ballistic thermal transport regime, with a corresponding increase in the interface resistivity for line widths smaller than the phonon mean free path in the substrate. Resistivities more than three times higher than the bulk value are measured for the smallest line widths of 65 nm. Our findings are relevant to the modeling and design of heat transport in nanoscale engineered systems, including nanoelectronics, photovoltaics and thermoelectric devices.

  9. Advanced Transport Delay Compensation Algorithms: Results of Delay Measurement and Piloted Performance Tests

    NASA Technical Reports Server (NTRS)

    Guo, Liwen; Cardullo, Frank M.; Kelly, Lon C.

    2007-01-01

    This report summarizes the results of delay measurement and piloted performance tests that were conducted to assess the effectiveness of the adaptive compensator and the state space compensator for alleviating the phase distortion of transport delay in the visual system in the VMS at the NASA Langley Research Center. Piloted simulation tests were conducted to assess the effectiveness of two novel compensators in comparison to the McFarland predictor and the baseline system with no compensation. Thirteen pilots with heterogeneous flight experience executed straight-in and offset approaches, at various delay configurations, on a flight simulator where different predictors were applied to compensate for transport delay. The glideslope and touchdown errors, power spectral density of the pilot control inputs, NASA Task Load Index, and Cooper-Harper rating of the handling qualities were employed for the analyses. The overall analyses show that the adaptive predictor results in slightly poorer compensation for short added delay (up to 48 ms) and better compensation for long added delay (up to 192 ms) than the McFarland compensator. The analyses also show that the state space predictor is fairly superior for short delay and significantly superior for long delay than the McFarland compensator.

  10. Direct measurement of calcium transport across chloroplast inner-envelope vesicles

    SciTech Connect

    Roh, M.H.; Shingles, R.; Cleveland, M.J.; McCarty, R.E.

    1998-12-01

    The initial rate of Ca{sup 2+} movement across the inner-envelope membrane of pea (Pisum sativum L.) chloroplasts was directly measured by stopped-flow spectrofluorometry using membrane vesicles loaded with the Ca{sup 2+}-sensitive fluorophore fura-2. Calibration of fura-2 fluorescence was achieved by combining a ratiometric method with Ca{sup 2+}-selective minielectrodes to determine pCa values. The initial rate of Ca{sup 2+} influx in predominantly right-side-out inner-envelope membrane vesicles was greater than that in largely inside-out vesicles. Ca{sup 2+} movement was stimulated by an inwardly directed electrochemical proton gradient across the membrane vesicles, an effect that was diminished by the addition of valinomycin in the presence of K{sup +}. In addition, Ca{sup 2+} was shown to move across the membrane vesicles in the presence of K{sup +} diffusion potential gradient. The potential-stimulated rate of Ca{sup 2+} transport was slightly inhibited by diltiazem and greatly inhibited by ruthenium red. Other pharmacological agents such as LaCl{sub 3}, verapamil, and nifedipine had little or no effect. These results indicate that Ca{sup 2+} transport across the chloroplast inner envelope can occur by a potential-stimulated uniport mechanism.

  11. Transport critical current measurements on a Cu-substituted BaFe2As2 superconductor

    NASA Astrophysics Data System (ADS)

    Garitezi, T. M.; Rosa, P. F. S.; Adriano, C.; Pagliuso, P. G.

    2014-05-01

    The critical current density Jc is a crucial parameter to establish the actual technological potential of a superconducting (SC) material. Furthermore, being proportional to the SC gap parameter, it can reveal important information about the microscopic nature of the SC state in a given material. The FeAs-based class of SC materials has been a focus of intense scientific investigation lately, but direct investigation of Jc by transport measurements is rather scarce in literature. For these materials, it is very interesting to map Jc as a function of their distinct SC tuning parameters such as applied pressure and chemical substitution. In this work, detailed investigation of the field, temperature, and pressure dependences of transport critical current density Jc for Cu-substituted BaFe2As2 single crystals is reported. In this particular material, Cu-substitution has a strong magnetic pair breaking effect. However, with increasing pressure, this sample shows an almost twofold increase of Tc, from 3.2 K to 6.9 K, which is followed by an increase in Jc. These observations are discussed considering the presence of magnetic pinning centers in the Fe-As plane, which, in principle, could suggest effective routes to increase Jc in the this class of materials.

  12. Measurement of effective atomic number of gunshot residues using scattering of gamma rays

    NASA Astrophysics Data System (ADS)

    Y?lmaz, Demet; Tur?ucu, Ahmet; Uzuno?lu, Zeynep; Korucu, Demet

    2014-09-01

    Better understanding of gunshot residues and the major elemental composition would be valuable to forensic scientists for their analysis work and interpretation of results. In the present work, the effective atomic numbers of gunshot residues (cartridge case, bullet core, bullet jacket and gunpowder) were analyzed using energy dispersive X-ray analysis (EDX). The scattering of 59.54 keV gamma rays is studied using a high-resolution HPGe detector. The experiment is performed on various elements with atomic number in the 4?Z?82. The intensity ratio of coherent to Compton scattered peaks, corrected for photo-peak efficiency of gamma detector and absorption of photons in the sample and air, is plotted as a function of atomic number and constituted a best-fit-curve. From this fit-curve, the respective effective atomic numbers of gunshot residues are determined.

  13. Measuring and Comparing Participation Patterns In Digital Repositories, Repositories by the Numbers Part I

    E-print Network

    Thomas, Chuck; McDonald, Robert H.

    2007-01-01

    library. (Wash. , D.C: Digital Library Federation). digital repositories certainly will be an important part of future "distributed libraries" (Digital Repositories, Repositories by the Numbers Part I Chuck Thomas, Florida Center for Library

  14. Effect of the number of measurement sites on land use regression models in estimating local air pollution

    NASA Astrophysics Data System (ADS)

    Basagaña, Xavier; Rivera, Marcela; Aguilera, Inmaculada; Agis, David; Bouso, Laura; Elosua, Roberto; Foraster, Maria; de Nazelle, Audrey; Nieuwenhuijsen, Mark; Vila, Joan; Künzli, Nino

    2012-07-01

    Land use regression (LUR) models are often used in epidemiologic studies to predict the air pollution exposure of health study participants. Such models are often based on a small to moderate number of air pollution measurement sites across the study area, and on a set of variables characterizing factors such as traffic patterns and surrounding land uses that are used as potential predictors. We used resampling techniques on a set of 148 measurement sites of NO2 in the urban area of Girona (Spain) to investigate the effect of the number of measurement sites on the LUR model performance, in particular on predictive ability and on the variables being chosen in the final model. In addition, we investigated the effect of the number of potential predictors and the variable selection algorithm used, and the consequences of the use of LUR predictions in regression models for a health outcome. Our results showed that, especially in small samples, both the adjusted within-sample R2 and the leave-one-out cross-validation R2 tended to give highly inflated values when compared to their prediction ability in a validation dataset. When the number of potential predictors was high, LUR models developed with a small number of measurement sites tended to give higher within-sample and cross-validated R2 than those developed with more sites. Validation dataset R2 showed a poor performance of models developed with a small number of sites that improved as the number of sites increased. Models developed with a small number of sites tended to select a different set of variables every time, were very sensitive to the number of potential predictors offered and resulted in stronger attenuation of coefficients when air pollution predictions were used in a health model. Our results suggest that LUR models aimed at characterizing local air pollution levels in complex urban settings should be based on a large number of measurement sites (>80 in our setting) and that the set of potential predictors should be restricted.

  15. Revealing dissipationless chiral edge channel in magnetic topological insulator via non-local transport measurement

    NASA Astrophysics Data System (ADS)

    Lee, Wei-Li; Kou, Xufeng; Guo, Shih-Ting; Fan, Yabin; Pan, Lei; Lang, Murong; Jiang, Ying; Shao, Qiming; Nie, Tianxiao; Murata, Koichi; Tang, Jianshi; Wang, Yong; He, Liang; Lee, Ting-Kuo; Wang, Kang L.

    2015-03-01

    We observed quantum anomalous Hall effect (QAHE) in our 10-quintuple layer Cr-doped (BiSb)2Te3 film grown by MBE technique. The Hall resistance Rxy attains quantized value of h/e2 (25.8 k ?) as temperature drops below 85 mK. Unlike previous report in a thinner Cr-doped (BiSb)2Te3 film, a finite longitudinal resistance is found in the QAHE regime and remains non-zero up to 15 Tesla suggesting the coexistence of the chiral edge channel and certain dissipative conduction channel. From macroscopic non-local transport measurements with leads separated by few millimeters, we further identify the dissipationless nature of the chiral edge channel associated with the QAHE. Detailed T-dependence and field-dependence of the non-local signals will be presented and discussed.

  16. Opacity and Transport Measurements Reveal That Dilute Plasma Models of Sonoluminescence Are Not Valid

    NASA Astrophysics Data System (ADS)

    Khalid, Shahzad; Kappus, Brian; Weninger, Keith; Putterman, Seth

    2012-03-01

    A strong interaction between a nanosecond laser and a 70 ?m radius sonoluminescing plasma is achieved. The overall response of the system results in a factor of 2 increase in temperature as determined by its spectrum. Images of the interaction reveal that light energy is absorbed and trapped in a region smaller than the sonoluminescence emitting region of the bubble for over 100 ns. We interpret this opacity and transport measurement as demonstrating that sonoluminescencing bubbles can be 1000 times more opaque than what follows from the Saha equation of statistical mechanics in the ideal plasma limit. To address this discrepancy, we suggest that the effects of strong Coulomb interactions are an essential component of a first principles theory of sonoluminescence.

  17. Secondary fusion coupled deuteron/triton transport simulation and thermal-to-fusion neutron convertor measurement

    SciTech Connect

    Wang, G. B.; Wang, K.; Liu, H. G.; Li, R. D.

    2013-07-01

    A Monte Carlo tool RSMC (Reaction Sequence Monte Carlo) was developed to simulate deuteron/triton transportation and reaction coupled problem. The 'Forced particle production' variance reduction technique was used to improve the simulation speed, which made the secondary product play a major role. The mono-energy 14 MeV fusion neutron source was employed as a validation. Then the thermal-to-fusion neutron convertor was studied with our tool. Moreover, an in-core conversion efficiency measurement experiment was performed with {sup 6}LiD and {sup 6}LiH converters. Threshold activation foils was used to indicate the fast and fusion neutron flux. Besides, two other pivotal parameters were calculated theoretically. Finally, the conversion efficiency of {sup 6}LiD is obtained as 1.97x10{sup -4}, which matches well with the theoretical result. (authors)

  18. Measurement of anisotropic energy transport in flowing polymers by using a holographic technique

    PubMed Central

    Schieber, Jay D.; Venerus, David C.; Bush, Kendall; Balasubramanian, Venkat; Smoukov, Stoyan

    2004-01-01

    Almost no experimental data exist to test theories for the nonisothermal flow of complex fluids. To provide quantitative tests for newly proposed theories, we have developed a holographic grating technique to study energy transport in an amorphous polymer melt subject to flow. Polyisobutylene with weight-averaged molecular mass of 85 kDa is sheared at a rate of 10 s–1, and all nonzero components of the thermal conductivity tensor are measured as a function of time, after cessation. Our results are consistent with proposed generalizations to the energy balance for microstructural fluids, including a generalized Fourier's law for anisotropic media. The data are also consistent with a proposed stress-thermal rule for amorphous polymer melts. Confirmation of the universality of these results would allow numerical modelers to make quantitative predictions for the nonisothermal flow of polymer melts. PMID:15340152

  19. Testing Observational Tracers of Turbulence with Numerical Simulations: Measuring the Sonic Mach Number in Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Burkhart, B.; Lazarian, A.; Correia, C.; Ossenkopf, V.; Stutzki, J.; de Medeiros, J. R.

    2014-09-01

    Astrophysical simulations provide a unique opportunity to test and verify observational diagnostics of the physics of the interstellar medium. In these proceedings, we highlight how s imulations of MHD turbulence can increase the accuracy and understanding of observational tracers of important plasma parameters, such as the sonic Mach number, in molecular clouds. For this purpose we analyze MHD simulations which include post-processing to take radiative transfer effects of 13CO emission and absorption into account. We find very good agreement between the linewidth estimated sonic Mach number and the actual sonic Mach number of the simulations for optically thin 13CO. However, we find that opacity broadening causes Ms to be overestimated by a factor of ? 1.16-1.3 when calculated from optically thick 13CO lines. We also find that there is a dependency on the magnetic field: super-Alfvénic turbulence shows increased line broadening as compared with sub-Alfvénic turbulence for all values of optical depth for the line of sight perpendicular to an magnetic field. These results have implications for the observationally derived sonic Mach number-density standard deviation (??/) relationship, ?2?/=b2M s2, and the related column density standard deviation (?N/(N)) sonic Mach number relationship, which we briefly discuss. The turbulence sonic Mach number is an important parameter of star formation models and the results highlighted in these proceedings provide researchers with increased understanding of these parameters derived from observations.

  20. TRANSPORTATION TRANSPORTATION

    E-print Network

    TEXASTRANS TEXAS TRANSPORTATION HALL HONOR OF HALL HONOR OF TEXASTRAN HALL HONOR OF TEXASTRAN HALL HONOR OF Inductees #12;2 TEXAS TRANSPORTATION HALL HONOR OF L NOR OF Texas is recognized as having one of the finest multimodal transportation systems in the world. The existence of this system has been key

  1. Measurement of Fracture Aperture Fields Using Ttransmitted Light: An Evaluation of Measurement Errors and their Influence on Simulations of Flow and Transport through a Single Fracture

    SciTech Connect

    Detwiler, Russell L.; Glass, Robert J.; Pringle, Scott E.

    1999-05-06

    Understanding of single and multi-phase flow and transport in fractures can be greatly enhanced through experimentation in transparent systems (analogs or replicas) where light transmission techniques yield quantitative measurements of aperture, solute concentration, and phase saturation fields. Here we quanti@ aperture field measurement error and demonstrate the influence of this error on the results of flow and transport simulations (hypothesized experimental results) through saturated and partially saturated fractures. find that precision and accuracy can be balanced to greatly improve the technique and We present a measurement protocol to obtain a minimum error field. Simulation results show an increased sensitivity to error as we move from flow to transport and from saturated to partially saturated conditions. Significant sensitivity under partially saturated conditions results in differences in channeling and multiple-peaked breakthrough curves. These results emphasize the critical importance of defining and minimizing error for studies of flow and transpoti in single fractures.

  2. Magnetic field measurements for study of fast electron transport in magnetized HED plasma

    NASA Astrophysics Data System (ADS)

    Sawada, Hiroshi; Griffin, Brandon; Presura, Radu; Haque, Showera; Sentoku, Yasuhiko

    2014-10-01

    Interaction of megagauss magnetic fields with high energy density (HED) plasma is of great interest in the field of magnetized plasma. The field changes fundamental properties of the HED plasma such as thermal and magnetic diffusion. A coupled capability utilizing the 1.0 MA Zebra pulsed power generator and the 50 TW Leopard laser at Nevada Terawatt Facility enables to create such a condition for studies of magnetized plasma properties. We have conducted an experiment to measure magnetic fields generated by a 1.0 MA, 100 ns Zebra pulsed current in stainless steel coils. Using a 532 nm continuous laser from a single longitudinal mode laser system, the temporal change in the magnetic field was measured with the Faraday rotation in F2 glass. The probe laser passing through the 1.5 mm in radius and 1.75 mm thick glass placed in the vicinity of the inductive coils was split with a Glan-Taylor prism to measure vertical and horizontal polarization components with photodiodes. We will present the analysis of the experimental result and a design of a coupled experiment for study of fast electron transport in the magnetized plasma.

  3. Earth strain measurements with the transportable laser ranging system: Field techniques and planning

    NASA Technical Reports Server (NTRS)

    Nakamura, Y.; Dorman, H. J.; Cahill, T.

    1982-01-01

    The potential of the transportable laser ranging system for monitoring the ground deformation around satellite ranging stations and other geodetic control points was examined with emphasis on testing the usefulness of the relative alteration technique. The temporal variation of the ratio of the length of each survey line to the mean length of all survey lines in a given area is directly related to the mean shear strain rate for the area. The data from a series of experimental measurements taken over the Los Angeles basin from a TLRS station at Mt. Wilson show that such ratios can be determined to an accuracy of one part in 10 million with a measurement program lasting for three days and without using any corrections for variations in atmospheric conditions. A numerical experiment using a set of hypothetical data indicates that reasonable estimates of the present shear strain rate and the direction of the principal axes in southern California can be deduced from such measurements over an interval of one to two years.

  4. Evaluating field measured soil hydraulic properties in water transport simulations using the RZWQM

    NASA Astrophysics Data System (ADS)

    Cameira, M. R.; Ahuja, L.; Fernando, R. M.; Pereira, L. S.

    2000-09-01

    Better understanding and quantification of infiltration and water movement in macroporous soils is extremely important, both for optimising the use of water in agriculture and for minimising preferential transport of nitrogen and pesticides to groundwater. The methods of measuring soil hydraulic properties by conventional methods do not distinguish between the soil matrix and macropores that may be present in the sampled soil. The objective of this work is to evaluate a two-domain model of infiltration using the conventionally measured soil hydraulic properties considered as soil matrix properties, supplemented by macropore flow capacity measured with a tension infiltrometer. To determine the soil hydraulic characteristics a two step method was used, using field data from an infiltration redistribution experiment and running the Root Zone Water Quality Model (RZWQM) in the inverse mode. The results indicate that there is the need to develop a new technique to determine appropriate soil matrix and macropore properties in macroporous field soils. The hydraulic properties determined by conventional methods are apparently the properties of soil matrix, but seem to miss the effect of larger pores that are below the 1.0 mm diameter assumed to be the lower limit for macropores. The macropore properties determined with a tension infiltrometer apparently do not distinguish between continuous and dead-end macropores, and do not give any indication about the continuity of macropores with depth.

  5. Aircraft measurements from Fennec: giant particles, optical properties, and effects of transport

    NASA Astrophysics Data System (ADS)

    Ryder, Claire; Rosenberg, Phil; Highwood, Ellie; McQuaid, Jim; Washington, Richard; Sodemann, Harald; Formenti, Paola; Marsham, John; Todd, Martin

    2015-04-01

    During June 2011 and 2012 the Fennec project took place in the Western Sahara desert. Ground based and airborne measurements were taken in remote desert regions of Mali, Mauritania and Algeria. In-situ aircraft measurements of Saharan dust from the 2011 flights will be presented, with size distributions extending to 300 ?m, representing measurements extending further into the coarse mode than previously published for airborne Saharan dust. A significant coarse mode was present in the size distribution measurements with effective diameter (deff) from 2.3 to 19.4 ?m and coarse mode volume median diameter (dvc) from 5.8 to 45.3 ?m. The mean size distribution had a larger relative proportion of coarse mode particles than previous aircraft measurements with significant contribution from the 'giant mode' - particles larger than 38 microns. Properties of dust size distribution and optical properties will be presented in relation to dust age since uplift and altitude. Vertical distributions of dust over desert (for both fresh and aged dust events) and the Eastern Atlantic Ocean from 42 aircraft profiles will be presented, demonstrating how size distributions and optical properties change during the early stages of the dust lifecycle. Size distributions show a loss of 60 to 90% of particles larger than 30 microns 12 h after uplift. Single scattering albedo increases from 0.92 to 0.94 to 0.95 between fresh, aged, and Eastern Atlantic dust profiles. Finally the impact of transport and changing optical properties on the radiative effect of dust will be examined.

  6. Do we really need a large number of particles to simulate bimolecular reactive transport with random walk methods? A kernel density estimation approach

    NASA Astrophysics Data System (ADS)

    Rahbaralam, Maryam; Fernàndez-Garcia, Daniel; Sanchez-Vila, Xavier

    2015-12-01

    Random walk particle tracking methods are a computationally efficient family of methods to solve reactive transport problems. While the number of particles in most realistic applications is in the order of 106-109, the number of reactive molecules even in diluted systems might be in the order of fractions of the Avogadro number. Thus, each particle actually represents a group of potentially reactive molecules. The use of a low number of particles may result not only in loss of accuracy, but also may lead to an improper reproduction of the mixing process, limited by diffusion. Recent works have used this effect as a proxy to model incomplete mixing in porous media. In this work, we propose using a Kernel Density Estimation (KDE) of the concentrations that allows getting the expected results for a well-mixed solution with a limited number of particles. The idea consists of treating each particle as a sample drawn from the pool of molecules that it represents; this way, the actual location of a tracked particle is seen as a sample drawn from the density function of the location of molecules represented by that given particle, rigorously represented by a kernel density function. The probability of reaction can be obtained by combining the kernels associated to two potentially reactive particles. We demonstrate that the observed deviation in the reaction vs time curves in numerical experiments reported in the literature could be attributed to the statistical method used to reconstruct concentrations (fixed particle support) from discrete particle distributions, and not to the occurrence of true incomplete mixing. We further explore the evolution of the kernel size with time, linking it to the diffusion process. Our results show that KDEs are powerful tools to improve computational efficiency and robustness in reactive transport simulations, and indicates that incomplete mixing in diluted systems should be modeled based on alternative mechanistic models and not on a limited number of particles.

  7. Anharmonic effects on a phonon-number measurement of a quantum-mesoscopic-mechanical D. H. Santamore

    E-print Network

    Roukes, Michael L.

    Anharmonic effects on a phonon-number measurement of a quantum-mesoscopic-mechanical oscillator D mechanical oscillator. In this scheme two NEMS oscillators are coupled via a term quadratic in the amplitude of oscillation for each oscillator. One NEMS oscillator is driven and strongly damped and becomes a transducer

  8. 40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration...

  9. 40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration...

  10. 40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration...

  11. 40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration...

  12. Historical Increase in the Number of Factors Measured by Commercial Tests of Cognitive Ability: Are We Overfactoring?

    ERIC Educational Resources Information Center

    Frazier, Thomas W.; Youngstrom, Eric A.

    2007-01-01

    A historical increase in the number of factors purportedly measured by commercial tests of cognitive ability may result from four distinct pressures including: increasingly complex models of intelligence, test publishers' desires to provide clinically useful assessment instruments with greater interpretive value, test publishers' desires to…

  13. An evaluation of the reliability of muscle fiber cross-sectional area and fiber number measurements in rat skeletal muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The reliability of estimating muscle fiber cross-sectional area (measure of muscle fiber size) and fiber number from only a subset of fibers in rat hindlimb muscle cross-sections has not been systematically evaluated. This study examined the variability in mean estimates of fiber cross-s...

  14. Transport and seismoelectric properties of porous permeable rock : numerical modeling and laboratory measurements

    E-print Network

    Zhan, Xin, Ph. D. Massachusetts Institute of Technology

    2010-01-01

    The objective of this thesis is to better understand the transport and seismoelectric (SE) properties of porous permeable rock. Accurate information of rock transport properties, together with pore geometry, can aid us to ...

  15. How to estimate how well people estimate: Evaluating measures of individual differences in the approximate number system.

    PubMed

    Chesney, Dana; Bjalkebring, Par; Peters, Ellen

    2015-11-01

    At a glance, one can tell that there are more individual fruits in a pile of 100 apples than in a pile of 20 watermelons, even though the watermelons take up more space. People's ability to distinguish between such nonsymbolic numerical magnitudes without counting is derived from the approximate number system (ANS). Individual differences in this ability (ANS acuity) are emerging as an important predictor in research areas ranging from children's understanding of arithmetic to adults' use of numbers in judgment and decision making. However, ANS acuity must be assessed through proxy tasks that might not show consistent relationships with this ability. Furthermore, practical limitations often confine researchers to using abbreviated measures of this ability, whose reliability is questionable. Here, we developed and tested several novel ANS acuity measures: a nonsymbolic discrimination task designed to account for participants' lapses in attention; three estimation tasks, including one task in which participants estimated the number of dots in a briefly presented set, one in which they estimated the ratio between two sets of dots, and one in which they indicated the correct position of a set of dots on a "number-line" anchored by two sets of dots, as well as a similar number-line task using symbolic numbers. The results indicated that the discrimination task designed to account for lapses in participants' attention holds promise as a reliable measure of ANS acuity, considered in terms of both internal and test-retest reliability. We urge researchers to use acuity measures whose reliability has been demonstrated. PMID:26335207

  16. Electrical Noise and the Measurement of Absolute Temperature, Boltzmann's Constant and Avogadro's Number.

    ERIC Educational Resources Information Center

    Ericson, T. J.

    1988-01-01

    Describes an apparatus capable of measuring absolute temperatures of a tungsten filament bulb up to normal running temperature and measuring Botzmann's constant to an accuracy of a few percent. Shows that electrical noise techniques are convenient to demonstrate how the concept of temperature is related to the micro- and macroscopic world. (CW)

  17. Correlated biofilm imaging, transport and metabolism measurements via combined nuclear magnetic resonance and confocal microscopy.

    PubMed

    McLean, Jeffrey S; Ona, Ositadinma N; Majors, Paul D

    2008-02-01

    Bacterial biofilms are complex, three-dimensional communities found nearly everywhere in nature and are also associated with many human diseases. Detailed metabolic information is critical to understand and exploit beneficial biofilms as well as combat antibiotic-resistant, disease-associated forms. However, most current techniques used to measure temporal and spatial metabolite profiles in these delicate structures are invasive or destructive. Here, we describe imaging, transport and metabolite measurement methods and their correlation for live, non-invasive monitoring of biofilm processes. This novel combination of measurements is enabled by the use of an integrated nuclear magnetic resonance (NMR) and confocal laser scanning microscope (CLSM). NMR methods provide macroscopic structure, metabolic pathway and rate data, spatially resolved metabolite concentrations and water diffusion profiles within the biofilm. In particular, current depth-resolved spectroscopy methods are applied to detect metabolites in 140-190 nl volumes within biofilms of the dissimilatory metal-reducing bacterium Shewanella oneidensis strain MR-1 and the oral bacterium implicated in caries disease, Streptococcus mutans strain UA159. The perfused sample chamber also contains a transparent optical window allowing for the collection of complementary fluorescence information using a unique, in-magnet CLSM. In this example, the entire three-dimensional biofilm structure was imaged using magnetic resonance imaging. This was then correlated to a fluorescent CLSM image by employing a green fluorescent protein reporter construct of S. oneidensis. Non-invasive techniques such as described here, which enable measurements of dynamic metabolic processes, especially in a depth-resolved fashion, are expected to advance our understanding of processes occurring within biofilm communities. PMID:18253132

  18. Correlated biofilm imaging, transport and metabolism measurements via combined nuclear magnetic resonance and confocal microscopy

    PubMed Central

    McLean, Jeffrey S; Ona, Ositadinma N; Majors, Paul D

    2015-01-01

    Bacterial biofilms are complex, three-dimensional communities found nearly everywhere in nature and are also associated with many human diseases. Detailed metabolic information is critical to understand and exploit beneficial biofilms as well as combat antibiotic-resistant, disease-associated forms. However, most current techniques used to measure temporal and spatial metabolite profiles in these delicate structures are invasive or destructive. Here, we describe imaging, transport and metabolite measurement methods and their correlation for live, non-invasive monitoring of biofilm processes. This novel combination of measurements is enabled by the use of an integrated nuclear magnetic resonance (NMR) and confocal laser scanning microscope (CLSM). NMR methods provide macroscopic structure, metabolic pathway and rate data, spatially resolved metabolite concentrations and water diffusion profiles within the biofilm. In particular, current depth-resolved spectroscopy methods are applied to detect metabolites in 140–190 nl volumes within biofilms of the dissimilatory metal-reducing bacterium Shewanella oneidensis strain MR-1 and the oral bacterium implicated in caries disease, Streptococcus mutans strain UA159. The perfused sample chamber also contains a transparent optical window allowing for the collection of complementary fluorescence information using a unique, in-magnet CLSM. In this example, the entire three-dimensional biofilm structure was imaged using magnetic resonance imaging. This was then correlated to a fluorescent CLSM image by employing a green fluorescent protein reporter construct of S. oneidensis. Non-invasive techniques such as described here, which enable measurements of dynamic metabolic processes, especially in a depth-resolved fashion, are expected to advance our understanding of processes occurring within biofilm communities. PMID:18253132

  19. Serial Measurements of Apoptotic Cell Numbers Provide Better Acceptance Criterion for PBMC Quality than a Single Measurement Prior to the T Cell Assay

    PubMed Central

    Wunsch, Marie; Caspell, Richard; Kuerten, Stefanie; Lehmann, Paul V.; Sundararaman, Srividya

    2015-01-01

    As soon as Peripheral Blood Mononuclear Cells (PBMC) are isolated from whole blood, some cells begin dying. The rate of apoptotic cell death is increased when PBMC are shipped, cryopreserved, or stored under suboptimal conditions. Apoptotic cells secrete cytokines that suppress inflammation while promoting phagocytosis. Increased numbers of apoptotic cells in PBMC may modulate T cell functions in antigen-triggered T cell assays. We assessed the effect of apoptotic bystander cells on a T cell ELISPOT assay by selectively inducing B cell apoptosis using ?-CD20 mAbs. The presence of large numbers of apoptotic B cells did not affect T cell functionality. In contrast, when PBMC were stored under unfavorable conditions, leading to damage and apoptosis in the T cells as well as bystander cells, T cell functionality was greatly impaired. We observed that measuring the number of apoptotic cells before plating the PBMC into an ELISPOT assay did not reflect the extent of PBMC injury, but measuring apoptotic cell frequencies at the end of the assay did. Our data suggest that measuring the numbers of apoptotic cells prior to and post T cell assays may provide more stringent PBMC quality acceptance criteria than measurements done only prior to the start of the assay. PMID:25585298

  20. Measuring acuity of the approximate number system reliably and validly: the evaluation of an adaptive test procedure

    PubMed Central

    Lindskog, Marcus; Winman, Anders; Juslin, Peter; Poom, Leo

    2013-01-01

    Two studies investigated the reliability and predictive validity of commonly used measures and models of Approximate Number System acuity (ANS). Study 1 investigated reliability by both an empirical approach and a simulation of maximum obtainable reliability under ideal conditions. Results showed that common measures of the Weber fraction (w) are reliable only when using a substantial number of trials, even under ideal conditions. Study 2 compared different purported measures of ANS acuity as for convergent and predictive validity in a within-subjects design and evaluated an adaptive test using the ZEST algorithm. Results showed that the adaptive measure can reduce the number of trials needed to reach acceptable reliability. Only direct tests with non-symbolic numerosity discriminations of stimuli presented simultaneously were related to arithmetic fluency. This correlation remained when controlling for general cognitive ability and perceptual speed. Further, the purported indirect measure of ANS acuity in terms of the Numeric Distance Effect (NDE) was not reliable and showed no sign of predictive validity. The non-symbolic NDE for reaction time was significantly related to direct w estimates in a direction contrary to the expected. Easier stimuli were found to be more reliable, but only harder (7:8 ratio) stimuli contributed to predictive validity. PMID:23964256

  1. Quantifying single gene copy number by measuring fluorescent probe lengths on combed genomic DNA

    E-print Network

    Michalet, Xavier

    coverslip. It has the advantage that a large number of genomes can be combed per coverslip, which allows. Aneuploidies associated with the development of a variety of malignancies and genetic diseases involve genes by using arrays of cloned DNA on a diagnostic chip, but the ability to reliably quantify subtle

  2. Application of acoustic doppler current profilers for measuring three-dimensional flow fields and as a surrogate measurement of bedload transport

    USGS Publications Warehouse

    Conaway, J.S.

    2005-01-01

    Acoustic Doppler current profilers (ADCPs) have been in use in the riverine environment for nearly 20 years. Their application primarily has been focused on the measurement of streamflow discharge. ADCPs emit high-frequency sound pulses and receive reflected sound echoes from sediment particles in the water column. The Doppler shift between transmitted and return signals is resolved into a velocity component that is measured in three dimensions by simultaneously transmitting four independent acoustical pulses. To measure the absolute velocity magnitude and direction in the water column, the velocity magnitude and direction of the instrument must also be computed. Typically this is accomplished by ensonifying the streambed with an acoustical pulse that also provides a depth measurement for each of the four acoustic beams. Sediment transport on or near the streambed will bias these measurements and requires external positioning such as a differentially corrected Global Positioning Systems (GPS). Although the influence of hydraulic structures such as spur dikes and bridge piers is typically only measured and described in one or two dimensions, the use of differentially corrected GPS with ADCPs provides a fully three-dimensional measurement of the magnitude and direction of the water column at such structures. The measurement of these flow disturbances in a field setting also captures the natural pulsations of river flow that cannot be easily quantified or modeled by numerical simulations or flumes. Several examples of measured three-dimensional flow conditions at bridge sites throughout Alaska are presented. The bias introduced to the bottom-track measurement is being investigated as a surrogate measurement of bedload transport. By fixing the position of the ADCP for a known period of time the apparent velocity of the streambed at that position can be determined. Initial results and comparison to traditionally measured bedload values are presented. These initial results and those by other researchers are helping to determine a direction for further research of noncontact measurements of sediment transport. Copyright ASCE 2005.

  3. Measuring and modeling of a three-dimensional tracer transport in a planted soil column

    NASA Astrophysics Data System (ADS)

    Schroeder, N.; Javaux, M.; Haber-Pohlmeier, S.; Pohlmeier, A. J.; Huber, K.; Vereecken, H.; Vanderborght, J.

    2013-12-01

    Water flow from soil to root is driven by the plant transpiration and an important component of the hydrological cycle. The model R-SWMS combines three-dimensional (3D) water flow and solute transport in soil with a detailed description of root structure in three dimensions [1,2]. This model offers the possibility to calculate root water and solute uptake and flow within the roots, which enables explicit studies with respect to the distribution of water and solutes around the roots as well as local processes at the root-soil interface. In this study, we compared measured data from a tracer experiment using Magnetic Resonance Imaging (MRI) with simulations in order to assess the distribution and magnitude of the water uptake of a young lupine plant. An aqueous solution of the Gadolinium-complex (Gd-DTPA2-) was chosen as a tracer, as it behaves conservatively and is ideally suited for MRI. Water flow in the soil towards the roots can thus be visualized by following the change in tracer concentrations over time. The data were obtained by MRI, providing high resolution 3D images of the tracer distribution and root architecture structures by using a spin echo pulse sequence, which is strongly T1- weighted to be tracer sensitive [3], and T2 -weighted for root imaging [4]. This experimental setup was simulated using the 3D high-resolution numerical model R-SWMS. The comparison between MRI data and the simulations showed extensive effects of root architecture parameters on solute spreading. Although the results of our study showed the strength of combining non-invasive measurements and 3D modeling of solute and water flow in soil-root systems, where the derivation of plant hydraulic parameters such as axial and radial root conductivities is possible, current limitations were found with respect to MRI measurements and process description. [1] Javaux, M., T. Schröder, J. Vanderborght, and H. Vereecken (2008), Use of a Three-Dimensional Detailed Modeling Approach for Predicting Root Water Uptake, Vadose Zone Journal, 7(3), 1079-1079. [2] Schröder, N., M. Javaux, J. Vanderborght, B. Steffen, and H. Vereecken (2012), Effect of Root Water and Solute Uptake on Apparent Soil Dispersivity: A Simulation Study, Vadose Zone Journal, 11(3). [3 ]Haber-Pohlmeier, S., Bechtold, M., Stapf, S., and Pohlmeier, A. (2010). Water Flow Monitored by Tracer Transport in Natural Porous Media Using Magnetic Resonance Imaging. Vadose Zone Journal (9),835-845. [4] Stingaciu, L. R., Schulz, H., Pohlmeier, A., Behnke, S., Zilken, H., Vereecken, H., and Javaux, M. (2013). In Situ Root System Architecture Extraction from Magnetic Resonance Imaging for Application to Water Uptake Modeling. Vadose Zone Journal.

  4. Low velocity boron micro-pellet injector for edge and core impurity transport measurements

    SciTech Connect

    Kugel, H.W.; Gorman, J.; Kaita, R.; Munsat, T.; Stutman, D.

    1999-01-01

    A simple low velocity boron micro-pellet injector has been under development for Current Drive Experiment Upgrade (CDX-U) spherical torus edge and core impurity transport measurements, and wall conditioning. The injector consists of 16 barrels on a rotatable turret. Each barrel can be loaded with boron powder particles of diameters ranging from 1 to 40 {mu}m diameter in amounts ranging from less than 0.25 mg to more than 2 mg. A selected barrel is manually rotated into firing position using a vacuum precision rotary/linear motion feedthrough. A piezoelectric valve gas feed system triggered by CDX-U discharge timing is used to control H{sub 2} or D{sub 2} propellant gas at a cylinder pressure of 5.8{times}10{sup {minus}3thinsp} Pa (40 psi) or less. The injector barrel-to-CDX-U plasma edge distance is 0.47 m. Initial low mass injections of neutral boron beams were performed into CDX-U plasmas at a velocity of 23 m/s. Measurements were obtained with a filtered gated charge coupled device TV camera, bolometry, visible spectroscopy, and ultrasoft x-ray diagnostics. This work is in support of the present CDX-U research program and possible applications on National Spherical Torus Experiment. {copyright} {ital 1999 American Institute of Physics.}

  5. Correlated Biofilm Imaging, Transport and Metabolism Measurements via Combined Nuclear Magnetic Resonance and Confocal Microscopy

    SciTech Connect

    Mclean, Jeffrey S.; Ona, Ositadinma; Majors, Paul D.

    2008-02-18

    Bacterial biofilms are complex, three-dimensional, communities that are found nearly everywhere in nature1 and are being recognized as the cause of treatment-resistant infections1 2. Advanced methods are required to characterize their collective and spatial patterns of metabolism however most techniques are invasive or destructive. Here we describe the use of a combined confocal laser scanning microscopy (CLSM) and nuclear magnetic resonance (NMR) microscopy system to monitor structure, mass transport, and metabolism in active biofilms. Non-invasive NMR methods provide macroscopic structure along with spatially-resolved metabolite profiles and diffusion measurements. CLSM enables monitoring of cells by fluorescent protein reporters to investigate biofilm structure and gene expression concurrently. A planar sample chamber design facilitates depth-resolved measurements on 140 nL sample volumes under laminar flow conditions. The techniques and approaches described here are applicable to environmental and medically relevant microbial communities, thus providing key metabolic information for promoting beneficial biofilms and treating associated diseases.

  6. Major transport mechanisms of pyrethroids in residential settings and effects of mitigation measures.

    PubMed

    Davidson, Paul C; Jones, Russell L; Harbourt, Christopher M; Hendley, Paul; Goodwin, Gregory E; Slizy, Bradley A

    2014-01-01

    The major pathways for transport of pyrethroids were determined in runoff studies conducted at a full-scale test facility in central California, USA. The 6 replicate house lots were typical of front lawns and house fronts of California residential developments and consisted of stucco walls, garage doors, driveways, and residential lawn irrigation sprinkler systems. Each of the 6 lots also included a rainfall simulator to generate artificial rainfall events. Different pyrethroids were applied to 5 surfaces—driveway, garage door and adjacent walls, lawn, lawn perimeter (grass near the house walls), and house walls above grass. The volume of runoff water from each house lot was measured, sampled, and analyzed to determine the amount of pyrethroid mass lost from each surface. Applications to 3 of the house lots were made using the application practices typically used prior to recent label changes, and applications were made to the other 3 house lots according to the revised application procedures. Results from the house lots using the historic application procedures showed that losses of the compounds applied to the driveway and garage door (including the adjacent walls) were 99.75% of total measured runoff losses. The greatest losses were associated with significant rainfall events rather than lawn irrigation events. However, runoff losses were 40 times less using the revised application procedures recently specified on pyrethroid labels. PMID:24105831

  7. Measurements of dynamo electric field and momentum transport induced by fluctuations on HIST

    NASA Astrophysics Data System (ADS)

    Hirono, H.; Hanao, T.; Hyobu, T.; Ito, K.; Matsumoto, K.; Nakayama, T.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2012-10-01

    Coaxial Helicity injection (CHI) is an efficient current-drive method used in spheromak and spherical torus (ST) experiments. It is an important issue to investigate dynamo effect to explore CHI current drive mechanisms. To establish the dynamo model with two-fluid Hall effects, we verify the parallel mean-field Ohm's law balance. The spatial profiles of the MHD/Hall dynamo electric fields are measured by using Mach probe and Hall probe involving 3-axis magnetic pick-up coils. The MHD/Hall fluctuation-induced electromotive forces are large enough to sustain the mean toroidal current against the resistive decay. We have measured the electron temperature and the density with great accuracy by using a new electrostatic probe with voltage sweeping. The result shows that the electron temperature is high in the core region and low in the central open flux column (OFC), and the electron density is highest in the OFC region. The Hall dynamo becomes more dominant in a lower density region compared to the MHD dynamo. In addition, the fluctuation-induced Maxwell and Reynolds stresses are calculated to examine the fast radial transport of momentum from the OFC to the core region during the dynamo drive.

  8. Transport Property Measurements in Doped Bi2Te3 Single Crystals Obtained via Zone Melting Method

    NASA Astrophysics Data System (ADS)

    Jariwala, Bhakti; Shah, Dimple; Ravindra, N. M.

    2015-06-01

    Single crystals of Se- and Fe-doped Bi2Te3 have been synthesized via the zone melting method. Energy-dispersive x-ray and x-ray powder diffraction analyses have been carried out to identify the constituent elements and determine the lattice parameters of the grown crystals. Surface topological features of the as-grown single crystals have been studied. The transport properties of doped stoichiometric Bi2Te3 single crystals have been studied by measuring the thermoelectric power and electrical conductivity in the temperature range from 303 K to 473 K. The thermoelectric power, S, effective mass, scattering parameter, and Fermi energy have been calculated from thermoelectric power measurements. The temperature dependence of the electrical conductivity, ?, shows that the dopants in the crystals are thermally activated. All the crystals exhibit semiconducting behavior as confirmed by the temperature dependence of ? and S. The effective mass of electrons and the effective density of states have been determined and are reported for Bi2Te3- x Se x (0 ? x ? 0.3) and Bi2- y Fe y Te3 (0 ? y ? 0.3).

  9. Phase Averaged Measurements of the Coherent Structure of a Mach Number 0.6 Jet. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Emami, S.

    1983-01-01

    The existence of a large scale structure in a Mach number 0.6, axisymmetric jet of cold air was proven. In order to further characterize the coherent structure, phase averaged measurements of the axial mass velocity, radial velocity, and the product of the two were made. These measurements yield information about the percent of the total fluctuations contained in the coherent structure. These measured values were compared to the total fluctuation levels for each quantity and the result expressed as a percent of the total fluctuation level contained in the organized structure at a given frequency. These measurements were performed for five frequencies (St=0.16, 0.32, 0.474, 0.95, and 1.26). All of the phase averaged measurements required that the jet be artificially excited.

  10. Integration of field measurements and reactive transport modelling to evaluate contaminant transport at a sulfide mine tailings impoundment

    NASA Astrophysics Data System (ADS)

    Brookfield, A. E.; Blowes, D. W.; Mayer, K. U.

    2006-11-01

    Over a decade of field observations including geochemical, mineralogical and hydrological information are available on the generation of acid mine drainage from the Pistol Dam region of the P-area of Inco's tailings impoundment in Copper Cliff, Ontario. This work focuses on the integration and quantitative assessment of this data set using reactive transport modeling. The results of the reactive transport simulations are in general agreement with the field observations; however, exact agreement between the field and simulated results was not the objective of this study, and was not attained. Many factors contribute to the discrepancies between the field observations and simulation results including geochemical and hydrogeological complexities and necessary model simplifications. For example, fluctuating water levels observed at the site were averaged and described using a steady state flow system. In addition, the lack of representative thermodynamic and rate expression data contributed to the discrepancies between observations and simulation results, thus further research into the applicability of laboratory-derived thermodynamic and rate expression data to field conditions could minimize these discrepancies. Despite the discrepancies between the field observations and simulated results, integrating field observations with numerical modelling of the P-area tailings impoundment allowed for a more complete understanding of what affects the complex geochemical reactions.

  11. Temporal and spatial variability of aeolian sand transport: Implications for field measurements

    NASA Astrophysics Data System (ADS)

    Ellis, Jean T.; Sherman, Douglas J.; Farrell, Eugene J.; Li, Bailiang

    2012-01-01

    Horizontal variability is often cited as one source of disparity between observed and predicted rates of aeolian mass flux, but few studies have quantified the magnitude of this variability. Two field projects were conducted to evaluate meter-scale spatial and temporal in the saltation field. In Shoalhaven Heads, NSW, Australia a horizontal array of passive-style sand traps were deployed on a beach for 600 or 1200 s across a horizontal span of 0.80 m. In Jericoacoara, Brazil, traps spanning 4 m were deployed for 180 and 240 s. Five saltation sensors (miniphones) spaced 1 m apart were also deployed at Jericoacoara. Spatial variation in aeolian transport rates over small spatial and short temporal scales was substantial. The measured transport rates ( Q) obtained from the passive traps ranged from 0.70 to 32.63 g/m/s. When considering all traps, the coefficient of variation ( CoV) values ranged from 16.6% to 67.8%, and minimum and maximum range of variation coefficient ( RVC) values were 106.1% to 152.5% and 75.1% to 90.8%, respectively. The miniphone Q and CoV averaged 47.1% and 4.1% for the 1260 s data series, which was subsequently sub-sampled at 60-630 s intervals to simulate shorter deployment times. A statistically significant ( p < 0.002), inverselinear relationship was found between sample duration and CoV and between Q and CoV, the latter relationship also considering data from previous studies.

  12. Temperature alters solute transport in growth plate cartilage measured by in vivo multiphoton microscopy

    PubMed Central

    Serrat, Maria A.; Williams, Rebecca M.; Farnum, Cornelia E.

    2009-01-01

    Solute delivery to avascular cartilaginous plates is critical to bone elongation, and impaired transport of nutrients and growth factors in cartilage matrix could underlie many skeletal abnormalities. Advances in imaging technology have revolutionized our ability to visualize growth plates in vivo, but quantitative methods are still needed. We developed analytical standards for measuring solute delivery, defined by amount and rate of intravenous tracer entry, in murine growth plates using multiphoton microscopy. We employed an acute temperature model because of its well-established impact on bone circulation and tested the hypothesis that solute delivery changes positively with limb temperature when body core and respiration are held constant (36°C, 120 breaths/min). Tibial growth plates were surgically exposed in anesthetized 5-wk-old mice, and their hindlimbs were immersed in warm (36°C) or cool (23°C) saline (n = 6/group). After 30 min of thermal equilibration, we administered an intracardiac injection of fluorescein (50 ?l, 0.5%) and captured sequentially timed growth plate images spanning 10 min at standardized depth. Absolute growth plate fluorescence was normalized to vascular concentrations for interanimal comparisons. As predicted, more fluorescein infiltrated growth plates at 36°C, with standardized values nearly double those at 23°C. Changing initial limb temperature did not alter baseline values, suggesting a sustained response period. These data validate the sensitivity of our system and have relevance to strategies for enhancing localized delivery of therapeutic agents to growth plates of children. Applications of this technique include assessment of solute transport in models of growth plate dysfunction, particularly chondrodysplasias with matrix irregularities. PMID:19372302

  13. Detecting moisture transport pathways to the subtropical North Atlantic free troposphere using paired H2O-? D in situ measurements

    NASA Astrophysics Data System (ADS)

    González, Y.; Schneider, M.; Dyroff, C.; Rodríguez, S.; Christner, E.; García, O. E.; Cuevas, E.; Bustos, J. J.; Ramos, R.; Guirado-Fuentes, C.; Barthlott, S.; Wiegele, A.; Sepúlveda, E.

    2015-10-01

    We present two years of measurements of water vapour (H2O) and its isotopologue ratio (?D, the standardized ratio between H216O and HD16O) made at two remote mountain sites on Tenerife Island in the subtropical North Atlantic. We show that the data - if measured during nighttime - are well representative for the lower/middle free troposphere. We use the measured H2O-?D pairs, together with dust measurements and back-trajectory modelling for analysing the moisture pathways to this region. We can identify four principally different transport pathways. The first two pathways are linked to transport from high altitudes and high latitudes, whereby the respective air can be dry, due to last condensation occurring at low temperatures, as well as humid, due to cross isentropic mixing with lower level and more humid air during transport since last condensation. The third pathway is transport from lower latitudes and lower altitudes, whereby we can identify rain re-evaporation as an occasional source of moisture. The fourth pathway is linked to the African continent, where during summer dry convection processes over the Sahara very effectively inject humidity from the boundary layer to higher altitudes. This so-called Saharan Air Layer (SAL) is then advected westward over the Atlantic and contributes to moisten the free troposphere. We demonstrate that different pathways leave distinct fingerprints on the measured H2O-?D pairs.

  14. Improvement of storage, handling, and transportability of fine coal. Quarterly technical progress report number 8, October 1--December 31, 1995

    SciTech Connect

    1996-03-15

    The Mulled Coal process was developed as a means of overcoming the adverse handling characteristics of wet fine coal without thermal drying. The process involves the addition of a low cost, harmless reagent to wet fine coal using off-the-shelf mixing equipment. Based on laboratory- and bench-scale testing, Mulled coal can be stored, shipped, and burned without causing any of the plugging, pasting, carryback and freezing problems normally associated with wet coal. On the other hand, Mulled Coal does not cause the fugitive and airborne dust problems normally associated with thermally dried coal. The objectives of this project are to demonstrate that: the Mulled Coal process, which has been proved to work on a wide range of wet fine coals at bench scale, will work equally well on a continuous basis, producing consistent quality, and at a convincing rate of production in a commercial coal preparation plant; the wet product from a fine coal cleaning circuit can be converted to a solid fuel form for ease of handling and cost savings in storage and rail car transportation; and a wet fine coal product thus converted to a solid fuel form, can be stored, shipped, and burned with conventional fuel handling, transportation, and combustion systems.

  15. Determination of car on-road black carbon and particle number emission factors and comparison between mobile and stationary measurements

    NASA Astrophysics Data System (ADS)

    Ježek, I.; Drinovec, L.; Ferrero, L.; Carriero, M.; Mo?nik, G.

    2014-06-01

    We have used two methods for measuring emission factors (EF) in real driving conditions on five cars in a controlled environment: the stationary method, where the investigated vehicle drives by the stationary measurement platform and the composition of the plume is measured; and the chasing method, where a mobile measurement platform drives behind the investigated vehicle. We measured EF of black carbon and particle number concentration. The stationary method was tested for repeatability at different speeds and on a slope. The chasing method was tested on a test track and compared to the portable emission measurement system. We further developed the data processing algorithm for both methods, trying to improve consistency, determine the plume duration, limit the background influence and facilitate automatic processing of measurements. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions. Measuring EFs at different speeds or slopes did not significantly influence the EFs of different cars, hence we propose a new description of vehicle emissions that is not related to kinematic or engine parameters, rather we describe the vehicle EF with a characteristic value and a "super emission" tail.

  16. Determination of car on-road black carbon and particle number emission factors and comparison between mobile and stationary measurements

    NASA Astrophysics Data System (ADS)

    Ježek, I.; Drinovec, L.; Ferrero, L.; Carriero, M.; Mo?nik, G.

    2015-01-01

    We have used two methods for measuring emission factors (EFs) in real driving conditions on five cars in a controlled environment: the stationary method, where the investigated vehicle drives by the stationary measurement platform and the composition of the plume is measured, and the chasing method, where a mobile measurement platform drives behind the investigated vehicle. We measured EFs of black carbon and particle number concentration. The stationary method was tested for repeatability at different speeds and on a slope. The chasing method was tested on a test track and compared to the portable emission measurement system. We further developed the data processing algorithm for both methods, trying to improve consistency, determine the plume duration, limit the background influence and facilitate automatic processing of measurements. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions. Measuring EFs at different speeds or slopes did not significantly influence the EFs of different cars; hence, we propose a new description of vehicle emissions that is not related to kinematic or engine parameters, and we rather describe the vehicle EF with a characteristic value and a super emission tail.

  17. Life Expectancy at Birth: Teaching Guide. Measures of Progress: Poster Kit Number 1.

    ERIC Educational Resources Information Center

    World Bank, Washington, DC.

    This teaching guide accompanies the Life Expectancy at Birth poster kit, which presents statistics on life expectancy from 128 countries with populations of more than one million. The statistics relate to economic development and the changes it is bringing about in the world. Sometimes called indicators, the statistics are measures of social and…

  18. THE DEVELOPMENT OF ACHIEVEMENT MEASURES FOR TRADE AND TECHNICAL EDUCATION. PROGRESS REPORT NUMBER FOUR.

    ERIC Educational Resources Information Center

    BALDWIN, THOMAS S.

    DURING THE FIRST YEAR OF THE PROJECT, TO DISCOVER MORE ADEQUATE WAYS OF MEASURING IMPORTANT TACTILE-KINESTHETIC MODALITIES, APPROXIMATELY 40 INSTRUCTORS WITHIN THE NORTH CAROLINA DEPARTMENT OF COMMUNITY COLLEGES AND TECHNICAL INSTITUTES, WORKING WITH PROJECT STAFF MEMBERS, COMPLETED A CURRICULUM ANALYSIS FOR THE TECHNICAL OR TRADE SPECIALITY IN…

  19. New gauge fields from extension of space time parallel transport of vector spaces to the underlying number systems.

    SciTech Connect

    Benioff, P.

    2011-06-01

    One way of describing gauge theories in physics is to assign a vector space {bar V}{sub x} to each space time point x. For each x the field {psi} takes values {psi}(x) in {bar V}{sub x}. The freedom to choose a basis in each {bar V}{sub x} introduces gauge group operators and their Lie algebra representations to define parallel transformations between vector spaces. This paper is an exploration of the extension of these ideas to include the underlying scalar complex number fields. Here a Hilbert space, {bar H}{sub x}, as an example of {bar V}{sub x}, and a complex number field, {bar C}{sub x}, are associated with each space time point. The freedom to choose a basis in {bar H}{sub x} is expanded to include the freedom to choose complex number fields. This expansion is based on the discovery that there exist representations of complex (and other) number systems that differ by arbitrary scale factors. Compensating changes must be made in the basic field operations so that the relevant axioms are satisfied. This results in the presence of a new real valued gauge field A(x). Inclusion of A(x) into covariant derivatives in Lagrangians results in the description of A(x) as a gauge boson for which mass is optional. The great accuracy of QED suggests that the coupling constant of A(x) to matter fields is very small compared to the fine structure constant. Other physical properties of A(x) are not known at present.

  20. Coincidence measurements between fragment ions and the number of emitted electrons in heavy ion collisions with polyatomic molecules

    NASA Astrophysics Data System (ADS)

    Murai, T.; Majima, T.; Kishimoto, T.; Tsuchida, H.; Itoh, A.

    2012-11-01

    We have studied multiple ionization and multifragmentation of a chlorofluorocarbon molecule, CH2FCF3, induced by collisions of 580-keV C+ ions. Coincidence measurements of product ions and the number of emitted electrons from CH2FCF3 were performed under charge-changing conditions of C+ ? Cq+ (q = 0, 2, 3). A fully inclusive measurement regardless of outgoing projectile charge state was also performed by making coincidence with a pulsed ion beam. Mass distributions of fragment ions and number distributions of emitted electrons were both found to change greatly according to charge-changing conditions. Highly multiple ionization emitting up to about 10 electrons was observed in electron loss collisions.

  1. Measurements of surface-pressure fluctuations on the XB-70 airplane at local Mach numbers up to 2.45

    NASA Technical Reports Server (NTRS)

    Lewis, T. L.; Dods, J. B., Jr.; Hanly, R. D.

    1973-01-01

    Measurements of surface-pressure fluctuations were made at two locations on the XB-70 airplane for nine flight-test conditions encompassing a local Mach number range from 0.35 to 2.45. These measurements are presented in the form of estimated power spectral densities, coherence functions, and narrow-band-convection velocities. The estimated power spectral densities compared favorably with wind-tunnel data obtained by other experimenters. The coherence function and convection velocity data supported conclusions by other experimenters that low-frequency surface-pressure fluctuations consist of small-scale turbulence components with low convection velocity.

  2. A measurement of the muon number in showers using inclined events detected at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Rodriguez, G.

    2013-06-01

    The average muon content of measured showers with zenith angles between 62? and 80? detected at the Pierre Auger Observatory is obtained as a function of shower energy using a reconstruction method specifically designed for inclined showers and the hybrid character of the detector. The reconstruction of inclined showers relies on a comparison between the measured signals at ground and reference patterns at ground level from which an overall normalization factor is obtained. Since inclined showers are dominated by muons this factor gives the relative muon size. It can be calibrated using a subsample of showers simultaneously recorded with the fluorescence detector (FD) and the surface detector (SD) which provides an independent calorimetric measurement of the energy. The muon size obtained for each shower becomes a measurement of the relative number of muons with respect to the reference distributions. The precision of the measurement is assessed using simulated events which are reconstructed using exactly the same procedure. We compare the relative number of muons versus energy as obtained to simulations. Proton simulations with QGSJETII show a factor of 2.13 ± 0.04(stat) ± 0.11(sys) at 1019eV without significant variations in the energy range explored between 4 × 1018eV to 7 × 1019eV. We find that none of the current shower models, neither for proton nor for iron primaries, are able to predict as many muons as are observed.

  3. SEM technique for imaging and measuring electronic transport in nanocomposites based on electric field induced contrast

    DOEpatents

    Jesse, Stephen (Knoxville, TN) [Knoxville, TN; Geohegan, David B. (Knoxville, TN) [Knoxville, TN; Guillorn, Michael (Brooktondale, NY) [Brooktondale, NY

    2009-02-17

    Methods and apparatus are described for SEM imaging and measuring electronic transport in nanocomposites based on electric field induced contrast. A method includes mounting a sample onto a sample holder, the sample including a sample material; wire bonding leads from the sample holder onto the sample; placing the sample holder in a vacuum chamber of a scanning electron microscope; connecting leads from the sample holder to a power source located outside the vacuum chamber; controlling secondary electron emission from the sample by applying a predetermined voltage to the sample through the leads; and generating an image of the secondary electron emission from the sample. An apparatus includes a sample holder for a scanning electron microscope having an electrical interconnect and leads on top of the sample holder electrically connected to the electrical interconnect; a power source and a controller connected to the electrical interconnect for applying voltage to the sample holder to control the secondary electron emission from a sample mounted on the sample holder; and a computer coupled to a secondary electron detector to generate images of the secondary electron emission from the sample.

  4. High CO2 emissions through porous media: Transport mechanisms and implications for flux measurement and fractionation

    USGS Publications Warehouse

    Evans, William C.; Sorey, M.L.; Kennedy, B.M.; Stonestrom, D.A.; Rogie, J.D.; Shuster, D.L.

    2001-01-01

    Diffuse emissions of CO2 are known to be large around some volcanoes and hydrothermal areas. Accumulation-chamber measurements of CO2 flux are increasingly used to estimate the total magmatic or metamorphic CO2 released from such areas. To assess the performance of accumulation chamber systems at fluxes one to three orders of magnitude higher than normally encountered in soil respiration studies, a test system was constructed in the laboratory where known fluxes could be maintained through dry sand. Steady-state gas concentration profiles and fractionation effects observed in the 30-cm sand column nearly match those predicted by the Stefan-Maxwell equations, indicating that the test system was functioning successfully as a uniform porous medium. Eight groups of investigators tested their accumulation chamber equipment, all configured with continuous infrared gas analyzers (IRGA), in this system. Over a flux range of ~ 200-12,000 g m-2 day-1, 90% of their 203 flux measurements were 0-25% lower than the imposed flux with a mean difference of - 12.5%. Although this difference would seem to be within the range of acceptability for many geologic investigations, some potential sources for larger errors were discovered. A steady-state pressure gradient of -20 Pa/m was measured in the sand column at a flux of 11,200 g m-2 day-1. The derived permeability (50 darcies) was used in the dusty-gas model (DGM) of transport to quantify various diffusive and viscous flux components. These calculations were used to demonstrate that accumulation chambers, in addition to reducing the underlying diffusive gradient, severely disrupt the steady-state pressure gradient. The resultant diversion of the net gas flow is probably responsible for the systematically low flux measurements. It was also shown that the fractionating effects of a viscous CO2 efflux against a diffusive influx of air will have a major impact on some important geochemical indicators, such as N2/Ar, ??15N-N2, and 4He/22Ne. Published by Elsevier Science B.V.

  5. Dependence of Single-Interface Richtmyer-Meshkov Mixing on Mach Number using Simultaneous PIV and PLIF Measurements

    NASA Astrophysics Data System (ADS)

    Wilson, Brandon M.; Mejia-Alvarez, Ricardo; Prestridge, Kathy P.

    2013-11-01

    Richtmyer-Meshkov mixing is dependent upon initial interface perturbations, incident shock Mach number, Atwood number, and other fluid properties. The correlation between turbulence quantities and mixing parameters with these properties is not well-understood. The Vertical Shock Tube (VST) at Los Alamos National Lab is designed to measure turbulence and mixing from the Taylor micro-scale to the largest scales (mix width). We use simultaneous velocity (PIV) and density (PLIF) diagnostics to understand the effects of incident Mach number on statistically-invariant, multimode perturbations of an air-SF6 interface (Atwood number corrected for acetone diagnostic is A = 0.57). We quantify Ma effects on mixing at both large and small scales by measuring the time evolution of various mixing parameters (e . g . mixing width, Favre-averaged Reynolds stresses, and vorticity), and we compare these results to previous studies. Late mixing after the first shock resembles a turbulent flow, and we examine the nature of the turbulence and condition of turbulent transition.

  6. Resonance lamp absorption measurement of OH number density and temperature in expansion tube scramjet engine tests

    NASA Astrophysics Data System (ADS)

    Lempert, Walter R.; Trucco, Richard E.; Bittner, Robert D.

    1992-09-01

    In this paper, we report results of hydroxyl radical and static temperature measurements performed in the General Applied Science Laboratories-NASA HYPULSE expansion tube facility using the microwave resonance lamp absorption technique. Data were obtained as part of a series of hydrogen/air and hydrogen/oxygen combustion tests at stagnation enthalpies corresponding to Mach 17 flight speeds. Data from a representative injector configuration is compared to a full Navier-Stokes CFD solution.

  7. On-road measurements of particle number concentrations and size distributions in urban and tunnel environments

    NASA Astrophysics Data System (ADS)

    Gouriou, F.; Morin, J.-P.; Weill, M.-E.

    To obtain a good estimation of particle size distribution and concentration encountered by car passengers during their journeys, an electrical low-pressure impactor was installed in a car. Two measurement campaigns were carried out. The first one covered various traffic conditions in urban and rural areas near Rouen (France). The second campaign covered several journeys up and down the same tunnel. Measurements were recorded in the range 30 nm-10 ?m at 1 Hz frequency. The size distributions show two main shapes depending mainly on the concentration. For high concentrations the distributions correspond to diesel emissions with the mode comprised between 60 and 100 nm. For low concentrations the maximum of the distribution is located in the finest particle class of the device, between 30 and 60 nm. The concentrations observed are generally less than 50 000 part cm -3 but may reach more than 10 6 part cm -3 during specific road events. Likewise high-concentration values may be regularly observed at the end of the tunnel along which the concentration increases linearly, after a surprising decrease. One main conclusion is that on-road measurements are necessary for a correct evaluation of the conditions encountered by car passengers.

  8. Measuring the Number of M Dwarfs per M Dwarf Using Kepler Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Shan, Yutong; Johnson, John A.; Morton, Timothy D.

    2015-11-01

    We measure the binarity of detached M dwarfs in the Kepler field with orbital periods in the range of 1–90 days. Kepler’s photometric precision and nearly continuous monitoring of stellar targets over time baselines ranging from 3 months to 4 years make its detection efficiency for eclipsing binaries nearly complete over this period range and for all radius ratios. Our investigation employs a statistical framework akin to that used for inferring planetary occurrence rates from planetary transits. The obvious simplification is that eclipsing binaries have a vastly improved detection efficiency that is limited chiefly by their geometric probabilities to eclipse. For the M-dwarf sample observed by the Kepler Mission, the fractional incidence of eclipsing binaries implies that there are {0.11}-0.04+0.02 close stellar companions per apparently single M dwarf. Our measured binarity is higher than previous inferences of the occurrence rate of close binaries via radial velocity techniques, at roughly the 2? level. This study represents the first use of eclipsing binary detections from a high quality transiting planet mission to infer binary statistics. Application of this statistical framework to the eclipsing binaries discovered by future transit surveys will establish better constraints on short-period M+M binary rate, as well as binarity measurements for stars of other spectral types.

  9. VOLUME 74, NUMBER 21 P H Y S I C A L R E V I E W L E T T E R S 22 MAY 1995 Transport and Damping from Rotational Pumping in Magnetized Electron Plasmas

    E-print Network

    California at San Diego, University of

    VOLUME 74, NUMBER 21 P H Y S I C A L R E V I E W L E T T E R S 22 MAY 1995 Transport and Damping compressions caused by E 3 B rotation of the column through asymmetric confining potentials. The observed transport rates are in close agreement with theory. PACS numbers: 52.25.Wz, 51.20.+d, 52.20.Fs, 52.25.Fi

  10. Structures and properties of sulfonated ionomers probed by transport and mechanical measurements: The role of solute activity

    NASA Astrophysics Data System (ADS)

    Zhao, Qiao

    This work is focused on advancing the understanding of the structures and properties of sulfonated ionomer membranes in the context of Polymer Electrolyte Membrane Fuel Cell applications by transport and mechanical measurements. Transport and mechanical properties are two critical elements of ionomer membranes that govern the performance and longevity of fuel cells. Additionally, transport and mechanical property measurements can also provide valuable information about the structure of the ionomer membranes. It is essential to develop a comprehensive understanding of them under well controlled environmental conditions. The mechanism of water transport through Nafion membranes was found to be governed by water diffusivity, swelling of the hydrophilic phase and the interfacial transport across membrane/vapor interface. A transport model incorporating these parameters was developed and successfully employed to resolve water activity profiles in the membrane and make quantitative predictions under steady state and dynamic conditions. Experimental results of diffusivity, volume of mixing and tortuosity also provided hints about the hydration shell structure around in the hydrophilic domains of Nafion. The alcohol sorption and transport was found to be qualitatively similar to the behavior of water and the quantitative differences were attributed to the difference in molecular size. The transport of alcohol water mixtures through Nafion displayed significant non-ideality which was connected to the abnormal swelling and incomplete mixing within the hydrophilic domains. The mechanical properties of several perfluoro-sulfonated ionomer (PFSI) membranes were studied as functions of temperature and solute activity. The thermal transition found between 60-100°C was described as an order-disorder transition of the ionic clusters. Water and other polar solutes were found to plasticize PFSI below the transition but stiffen PFSI above the transition. The stiffening effect was attributed to polar solute induced re-clustering of the ionic domains. Two hydrocarbon model ionomer SPS and SPEEK were studied to further understand the structural-property relationships of ionomers. Water sorption and proton conductivity were enhanced with increasing ion content but water content was independent of ion content and proton conductivity scaled with hydrophilic volume fraction. Water transport was dependent on diffusion and interfacial transport, both of which were affected by the size and shape of the hydrophilic domains.

  11. Heat transfer measurements on an incidence-tolerant low pressure turbine blade in a high speed linear cascade at low to moderate Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Moualeu, Leolein Patrick Gouemeni

    Runway-independent aircraft are expected to be the future for short-haul flights by improving air transportation and reducing area congestion encountered in airports. The Vehicle Systems Program of NASA identified a Large Civil Tilt-Rotor, equipped with variable-speed power-turbine engines, as the best concept. At cruise altitude, the engine rotor-speed will be reduced by as much as the 50% of take-off speed. The large incidence variation in the low pressure turbine associated with the change in speed can be detrimental to the engine performance. Low pressure turbine blades in cruise altitude are more predisposed to develop regions of boundary layer separation. Typical phenomenon such as impinging wakes on downstream blades and mainstream turbulences enhance the complexity of the flow in low pressure turbines. It is therefore important to be able to understand the flow behavior to accurately predict the losses. Research facilities are seldom able to experimentally reproduce low Reynolds numbers at relevant engine Mach number. Having large incidence swing as an additional parameter in the investigation of the boundary layer development, on a low pressure turbine blade, makes this topic unique and as a consequence requires a unique facility to conduct the experimental research. The compressible flow wind tunnel facility at the University of North Dakota had been updated to perform steady state experiments on a modular-cascade, designed to replicate a large variation of the incidence angles. The high speed and low Reynolds number facility maintained a sealed and closed loop configuration for each incidence angle. The updated facility is capable to produce experimental Reynolds numbers as low as 45,000 and as high as 570,000 at an exit Mach number of 0.72. Pressure and surface temperature measurements were performed at these low pressure turbine conditions. The present thesis investigates the boundary layer development on the surface of an Incidence-tolerant blade. The heat transfer approach is the method used to obtain knowledge of the state of the boundary layer on the surface of the blade. Pressure and temperature distributions are acquired for Reynolds numbers of 50,000, 66,000, 228,000, and 568,000 at an exit Mach number of 0.72, and Reynolds numbers of 228,000, and 568,000 at an exit Mach number of 0.35. These experimental flow conditions are conducted at different flow inlet angles of 40°, 34.2°, 28°, 18°, 8°, -2.6°, -12°, and -17°, and at two free-stream turbulence levels. Results of the analyses performed show that as the incidence angle decreases, a region of laminar separation bubble forms on the pressure surface and grows toward the trailing-edge. It is also noted that the position of the leading-edge moves as the incidence angle varies. A transitional flow is observed on both the pressure and suction surfaces, mainly at the two highest incidence angles, for the high turbulence case. This investigation also reveals that the Stanton number increases as the mainstream turbulence increases, and that the Stanton number at the leading-edge increases as the Reynolds number decreases, as it is documented in the literature.

  12. Number theoretical design of optimal holographic targets for measurement of 3D target motion

    NASA Astrophysics Data System (ADS)

    Healy, John J.

    2015-08-01

    Motion detection retains a fascinating amount of scope for new ideas. Digital holography enables three-dimensional images to be recorded with high resolution and large depth of field. Appropriate design of a holographic target has the potential to unlock significant resolution gains from holographic measurement systems. In this paper, we explore the potential of proposed three-dimensional analogues of Costas arrays for the design of such targets. These innately sparse constructions have the potential to enable the use of additional compressive sensing techniques to unlock further gains in resolution.

  13. Pesticide Transport with Runoff from Fairway Turf: Measured Compared to Modeled

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pesticides applied to turf grass have been detected in surface waters raising concerns of their affect on water quality and interest in their source, hydrological transport and use of models to predict transport. TurfPQ, a pesticide runoff model for turf grass, was evaluated to determine its ability...

  14. Measurements and analysis of sediment transport capacity in shallow overland flow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Investigations on sediment transport in laboratory flume reveal a significant decrease in transport capacity when bed sediment conditions exhibit structured modes such as stripes and meanders. This decrease is 20% for the stripe mode and as much as 94% in large-scale modes such as meanders. Optical ...

  15. Measuring the Number of M-Dwarfs per M-Dwarf Using Kepler Eclipsing Binaries

    E-print Network

    Shan, Yutong; Morton, Timothy D

    2015-01-01

    We measure the binarity of detached M-dwarfs in the Kepler field with orbital periods in the range of 1-90 days. Kepler's photometric precision and nearly continuous monitoring of stellar targets over time baselines ranging from 3 months to 4 years make its detection efficiency for eclipsing binaries nearly complete over this period range and for all radius ratios. Our investigation employs a statistical framework akin to that used for inferring planetary occurrence rates from planetary transits. The obvious simplification is that eclipsing binaries have a vastly improved detection efficiency that is limited chiefly by their geometric probabilities to eclipse. For the M-dwarf sample observed by the Kepler Mission, the fractional incidence of eclipsing binaries implies that there are $0.11 ^{+0.02} _{-0.04}$ close stellar companions per apparently single M-dwarf. Our measured binarity is higher than previous inferences of the occurrence rate of close binaries via radial velocity techniques, at roughly the 2$\\s...

  16. Cryogenic wind tunnel technology. A way to measurement at higher Reynolds numbers

    NASA Technical Reports Server (NTRS)

    Beck, J. W.

    1984-01-01

    The goals, design, problems, and value of cryogenic transonic wind tunnels being developed in Europe are discussed. The disadvantages inherent in low-Reynolds-number (Re) wind tunnel simulations of aircraft flight at high Re are reviewed, and the cryogenic tunnel is shown to be the most practical method to achieve high Re. The design proposed for the European Transonic Wind tunnel (ETW) is presented: parameters include cross section. DISPLAY 83A46484/2 = 4 sq m, operating pressure = 5 bar, temperature = 110-120 K, maximum Re = 40 x 10 to the 6th, liquid N2 consumption = 40,000 metric tons/year, and power = 39,5 MW. The smaller Cologne subsonic tunnel being adapted to cryogenic use for preliminary studies is described. Problems of configuration, materials, and liquid N2 evaporation and handling and the research underway to solve them are outlined. The benefits to be gained by the construction of these costly installations are seen more in applied aerodynamics than in basic research in fluid physics. The need for parallel development of both high Re tunnels and computers capable of performing high-Re numerical analysis is stressed.

  17. Fluvial sediments a summary of source, transportation, deposition, and measurement of sediment discharge

    USGS Publications Warehouse

    Colby, B.R.

    1963-01-01

    This paper presents a broad but undetailed picture of fluvial sediments in streams, reservoirs, and lakes and includes a discussion of the processes involved in the movement of sediment by flowing water. Sediment is fragmental material that originates from the chemical or physical disintegration of rocks. The disintegration products may have many different shapes and may range in size from large boulders to colloidal particles. In general, they retain about the same mineral composition as the parent rocks. Rock fragments become fluvial sediment when they are entrained in a stream of water. The entrainment may occur as sheet erosion from land surfaces, particularly for the fine particles, or as channel erosion after the surface runoff has accumulated in streams. Fluvial sediments move in streams as bedload (particles moving within a few particle diameters of the streambed) or as suspended sediment in the turbulent flow. The discharge of bedload varies with several factors, which may include particle size and a type of effective shear on the surface of the streambed. The discharge of suspended sediment depends partly on concentration of moving sediment near the streambed and hence on discharge of bedload. However, the concentration of fine sediment near the streambed varies widely, even for equal flows, and, therefore, the discharge of fine sediment normally cannot be computed theoretically. The discharge of suspended sediment also depends on velocity, turbulence, depth of flow, and fall velocity of the particles. In general, the coarse sediment transported by a stream moves intermittently and is discharged at a rate that depends on properties of the flow and of the sediment. If an ample supply of coarse sediment is available at the surface of the streambed, the discharge of the coarse sediment, such as sand, can be roughly computed from properties of the available sediment and of the flow. On the other hand, much of the fine sediment in a stream usually moves nearly continuously at about the velocity of the flow, and even low flows can transport large amounts of fine sediment. Hence, the discharge of fine sediments, being largely dependent on the availability of fine sediment upstream rather than on the properties of the sediment and of the flow at a cross section, can seldom be computed from properties, other than concentrations based directly on samples, that can be observed at the cross section. Sediment particles continually change their positions in the flow; some fall to the streambed, and others are removed from the bed. Sediment deposits form locally or over large areas if the volume rate at which particles settle to the bed exceeds the volume rate at which particles are removed from the bed. In general, large particles are deposited more readily than small particles, whether the point of deposition is behind a rock, on a flood plain, within a stream channel, or at the entrance to a reservoir, a lake, or the ocean. Most samplers used for sediment observations collect a water-sediment mixture from the water surface to within a few tenths of a foot of the streambed. They thus sample most of the suspended sediment, especially if the flow is deep or if the sediment is mostly fine; but they exclude the bedload and some of the suspended sediment in a layer near the streambed where the suspended-sediment concentrations are highest. Measured sediment discharges are usually based on concentrations that are averages of several individual sediment samples for a cross section. If enough average concentrations for a cross section have been determined, the measured sediment discharge can be computed by interpolating sediment concentrations between sampling times. If only occasional samples were collected, an average relation between sediment discharge and flow can be used with a flow-duration curve to compute roughly the average or the total sediment discharges for any periods of time for which the flow-duration c

  18. Quantum dissipation theory and applications to quantum transport and quantum measurement in mesoscopic systems

    NASA Astrophysics Data System (ADS)

    Cui, Ping

    The thesis comprises two major themes of quantum statistical dynamics. One is the development of quantum dissipation theory (QDT). It covers the establishment of some basic relations of quantum statistical dynamics, the construction of several nonequivalent complete second-order formulations, and the development of exact QDT. Another is related to the applications of quantum statistical dynamics to a variety of research fields. In particular, unconventional but novel theories of the electron transfer in Debye solvents, quantum transport, and quantum measurement are developed on the basis of QDT formulations. The thesis is organized as follows. In Chapter 1, we present some background knowledge in relation to the aforementioned two themes of this thesis. The key quantity in QDT is the reduced density operator rho(t) ? trBrho T(t); i.e., the partial trace of the total system and bath composite rhoT(t) over the bath degrees of freedom. QDT governs the evolution of reduced density operator, where the effects of bath are treated in a quantum statistical manner. In principle, the reduced density operator contains all dynamics information of interest. However, the conventional quantum transport theory is formulated in terms of nonequilibrium Green's function. The newly emerging field of quantum measurement in relation to quantum information and quantum computing does exploit a sort of QDT formalism. Besides the background of the relevant theoretical development, some representative experiments on molecular nanojunctions are also briefly discussed. In chapter 2, we outline some basic (including new) relations that highlight several important issues on QDT. The content includes the background of nonequilibrium quantum statistical mechanics, the general description of the total composite Hamiltonian with stochastic system-bath interaction, a novel parameterization scheme for bath correlation functions, a newly developed exact theory of driven Brownian oscillator (DBO) systems, and its closely related solvation mode transformation of system-bath coupling Hamiltonian in general. The exact QDT of DBO systems is also used to clarify the validity of conventional QDT formulations that involve Markovian approximation. In Chapter 3, we develop three nonequivalent but all complete second-order QDT (CS-QDT) formulations. Two of them are of the conventional prescriptions in terms of time-local dissipation and memory kernel, respectively. The third one is called the correlated driving-dissipation equations of motion (CODDE). This novel CS-QDT combines the merits of the former two for its advantages in both the application and numerical implementation aspects. Also highlighted is the importance of correlated driving-dissipation effects on the dynamics of the reduced system. In Chapter 4, we construct an exact QDT formalism via the calculus on path integrals. The new theory aims at the efficient evaluation of non-Markovian dissipation beyond the weak system-bath interaction regime in the presence of time-dependent external field. By adopting exponential-like expansions for bath correlation function, hierarchical equations of motion formalism and continued fraction Liouville-space Green's function formalism are established. The latter will soon be used together with the Dyson equation technique for an efficient evaluation of non-perturbative reduced density matrix dynamics. The interplay between system-bath interaction strength, non-Markovian property, and the required level of hierarchy is also studied with the aid of simple spin-boson systems, together with the three proposed schemes to truncate the infinite hierarchy. In Chapter 5, we develop a nonperturbative theory of electron transfer (ET) in Debye solvents. The resulting exact and analytical rate expression is constructed on the basis of the aforementioned continued fraction Liouville-space Green's function formalism, together with the Dyson equation technique. Not only does it recover the celebrated Marcus' inversion and Kramers' turnover behaviors, the new theory also shows some disti

  19. DUF1220 copy number is linearly associated with increased cognitive function as measured by total IQ and mathematical aptitude scores.

    PubMed

    Davis, Jonathon M; Searles, Veronica B; Anderson, Nathan; Keeney, Jonathon; Raznahan, Armin; Horwood, L John; Fergusson, David M; Kennedy, Martin A; Giedd, Jay; Sikela, James M

    2015-01-01

    DUF1220 protein domains exhibit the greatest human lineage-specific copy number expansion of any protein-coding sequence in the genome, and variation in DUF1220 copy number has been linked to both brain size in humans and brain evolution among primates. Given these findings, we examined associations between DUF1220 subtypes CON1 and CON2 and cognitive aptitude. We identified a linear association between CON2 copy number and cognitive function in two independent populations of European descent. In North American males, an increase in CON2 copy number corresponded with an increase in WISC IQ (R (2) = 0.13, p = 0.02), which may be driven by males aged 6-11 (R (2) = 0.42, p = 0.003). We utilized ddPCR in a subset as a confirmatory measurement. This group had 26-33 copies of CON2 with a mean of 29, and each copy increase of CON2 was associated with a 3.3-point increase in WISC IQ (R (2) = 0.22, p = 0.045). In individuals from New Zealand, an increase in CON2 copy number was associated with an increase in math aptitude ability (R (2) = 0.10 p = 0.018). These were not confounded by brain size. To our knowledge, this is the first study to report a replicated association between copy number of a gene coding sequence and cognitive aptitude. Remarkably, dosage variations involving DUF1220 sequences have now been linked to human brain expansion, autism severity and cognitive aptitude, suggesting that such processes may be genetically and mechanistically inter-related. The findings presented here warrant expanded investigations in larger, well-characterized cohorts. PMID:25287832

  20. Equation of state and transport property measurements of warm dense matter.

    SciTech Connect

    Knudson, Marcus D.; Desjarlais, Michael Paul

    2009-10-01

    Location of the liquid-vapor critical point (c.p.) is one of the key features of equation of state models used in simulating high energy density physics and pulsed power experiments. For example, material behavior in the location of the vapor dome is critical in determining how and when coronal plasmas form in expanding wires. Transport properties, such as conductivity and opacity, can vary an order of magnitude depending on whether the state of the material is inside or outside of the vapor dome. Due to the difficulty in experimentally producing states near the vapor dome, for all but a few materials, such as Cesium and Mercury, the uncertainty in the location of the c.p. is of order 100%. These states of interest can be produced on Z through high-velocity shock and release experiments. For example, it is estimated that release adiabats from {approx}1000 GPa in aluminum would skirt the vapor dome allowing estimates of the c.p. to be made. This is within the reach of Z experiments (flyer plate velocity of {approx}30 km/s). Recent high-fidelity EOS models and hydrocode simulations suggest that the dynamic two-phase flow behavior observed in initial scoping experiments can be reproduced, providing a link between theory and experiment. Experimental identification of the c.p. in aluminum would represent the first measurement of its kind in a dynamic experiment. Furthermore, once the c.p. has been experimentally determined it should be possible to probe the electrical conductivity, opacity, reflectivity, etc. of the material near the vapor dome, using a variety of diagnostics. We propose a combined experimental and theoretical investigation with the initial emphasis on aluminum.

  1. Direct measurements of the ozone formation potential from dairy cattle emissions using a transportable smog chamber

    NASA Astrophysics Data System (ADS)

    Howard, Cody J.; Yang, Wenli; Green, Peter G.; Mitloehner, Frank; Malkina, Irina L.; Flocchini, Robert G.; Kleeman, Michael J.

    Tropospheric ozone continues to be an air pollution problem in the United States, particularly in California, Texas, and across the eastern seaboard. The obvious sources of ozone precursors have been largely controlled over the past several decades, leading to the critical examination of secondary sources. In particular, California has new air quality rules addressing agricultural sources of ozone precursors, including dairy farms. Some recent estimates predict that dairy cattle are second only to on-road vehicles as a leading source of ozone precursor emissions in California's San Joaquin Valley. The objective of this work was to directly measure the ozone formation potential from dairy housing. A transportable "smog" chamber was constructed and validated using organic gases known to be present in dairy emissions. The ozone formation potential of emissions from eight non-lactating dairy cows and their fresh waste was then directly evaluated in the field at a completely enclosed cow corral on the campus of the University of California, Davis. The results demonstrate that the majority of the ozone formation is explained by ethanol (EtOH) in the emissions from the dairy cows, not by acetone as previously thought. Ozone formation potential is generally small, with <20 ppb of ozone produced under typical conditions when EtOH concentrations were ˜200 ppb and NO x concentrations were ˜50 ppb. The results match our current understanding of atmospheric ozone formation potential, ruling out the possibility of unknown organic compounds in dairy emissions with significant ozone formation potential. Simulations carried out with a modified form of the Caltech Atmospheric Chemistry Mechanism verify that actual ozone formation from dairy emissions is much lower than what would be predicted using the current regulatory profiles. Based on these results, the ozone formation potential of emissions from dairy cattle in California seems to be lower than previously estimated.

  2. High-Reynolds Number Active Blowing Semi-Span Force Measurement System Development

    NASA Technical Reports Server (NTRS)

    Lynn, Keith C.; Rhew, Ray D.; Acheson, Michael J.; Jones, Gregory S.; Milholen, William E.; Goodliff, Scott L.

    2012-01-01

    Recent wind-tunnel tests at the NASA Langley Research Center National Transonic Facility utilized high-pressure bellows to route air to the model for evaluating aircraft circulation control. The introduction of these bellows within the Sidewall Model Support System significantly impacted the performance of the external sidewall mounted semi-span balance. As a result of this impact on the semi-span balance measurement performance, it became apparent that a new capability needed to be built into the National Transonic Facility s infrastructure to allow for performing pressure tare calibrations on the balance in order to properly characterize its performance under the influence of static bellows pressure tare loads and bellows thermal effects. The objective of this study was to design both mechanical calibration hardware and an experimental calibration design that can be employed at the facility in order to efficiently and precisely perform the necessary loadings in order to characterize the semi-span balance under the influence of multiple calibration factors (balance forces/moments and bellows pressure/temperature). Using statistical design of experiments, an experimental design was developed allowing for strategically characterizing the behavior of the semi-span balance for use in circulation control and propulsion-type flow control testing at the National Transonic Facility.

  3. Effect of using a cowl when measuring the fiber number concentration by the membrane filter method.

    PubMed

    Kauffer, Edmond; Eypert-Blaison, Céline

    2004-05-01

    This article compares samples taken with three different sampling heads: (1). open-faced sampling head, (2). open-faced sampling head with stainless-steel extension cowl, and (3). open-faced sampling head with graphite-impregnated extension cowl. Sampling was performed in three factories producing man-made mineral fibers (alkaline silicate fibers, refractory ceramic fibers, glass fibers). Flow rate was varied (1 L/min or 2 L/min). The average densities measured on the sampling filter for fibers of <3 microm in diameter varied from 19 to 91 fibers/mm(2). No significant difference in fiber density was observed in relation to the nature of the sampling head for fibers with a diameter of <3 microm. The deposits noted on the internal walls of the cowl were small and much less than that documented in the literature for man-made mineral fibers until now. They were greater for fibers with a diameter of >3 microm than for those with a diameter of <3 microm. For large-diameter fibers, it would appear that cowl deposit can be reduced by increasing the sampling flow rate. PMID:15238337

  4. Measurement of turbulence decorrelation during transport barrier evolution in a high-temperature fusion plasma.

    PubMed

    Nazikian, R; Shinohara, K; Kramer, G J; Valeo, E; Hill, K; Hahm, T S; Rewoldt, G; Ide, S; Koide, Y; Oyama, Y; Shirai, H; Tang, W

    2005-04-01

    A low power polychromatic beam of microwaves is used to diagnose the behavior of turbulent fluctuations in the core of the JT-60U tokamak during the evolution of the internal transport barrier. A continuous reduction in the size of turbulent structures is observed concomitant with the reduction of the density scale length during the evolution of the internal transport barrier. The density correlation length decreases to the order of the ion gyroradius, in contrast with the much longer scale lengths observed earlier in the discharge, while the density fluctuation level remain similar to the level before transport barrier formation. PMID:15904000

  5. Measurement of Turbulence Decorrelation during Transport Barrier Evolution in a High Temperature Fusion Plasma

    SciTech Connect

    R. Nazikian; K. Shinohara; G.J. Kramer; E. Valeo; K. Hill; T.S. Hahm; G. Rewoldt; S. Ide; Y. Koide; Y. Oyama; H. Shirai; W. Tang

    2005-03-29

    A low power polychromatic beam of microwaves is used to diagnose the behavior of turbulent fluctuations in the core of the JT-60U tokamak during the evolution of the internal transport barrier. A continuous reduction in the size of turbulent structures is observed concomitant with the reduction of the density scale length during the evolution of the internal transport barrier. The density correlation length decreases to the order of the ion gyroradius, in contrast to the much longer scale lengths observed earlier in the discharge, while the density fluctuation level remain similar to the level before transport barrier formation.

  6. Systemic oxygen transport derived by using continuous measured oxygen consumption after the Norwood procedure?an interim review

    PubMed Central

    Li, Jia

    2012-01-01

    The balance between systemic O2consumption (VO2) and O2delivery (DO2) is impaired in children after cardiopulmonary bypass surgery, with decreased DO2and increased VO2. The major goal, and the major challenge, of postoperative management has been to match DO2to VO2in order to sustain cellular metabolism, particularly in neonates after the Norwood procedure. While much effort has been put into augmenting cardiac output and DO2, VO2remains largely ignored. Respiratory mass spectrometry allows the precise and continuous measurement of VO2. Measured VO2, using the direct Fick principle, allows for the calculation of each element of systemic O2transport in the complex Norwood circulation. The actual measurements of O2transport have allowed us, in the past five years or so, to extensively investigate the Norwood physiology in terms of the VO2–DO2relationship and the factors affecting it in clinical treatments. Therefore, the first objective of this article is to introduce the technique of respiratory mass spectrometry and its adaption to measure VO2across paediatric ventilators with continuous flow. The second objective is to give an interim review of the main findings in our studies on systemic O2transport in 17 neonates in the first 72 h after the Norwood procedure. These findings include the profiles of systemic O2transport, the important contribution of VO2to the impaired balance of O2transport and the complex effects of some routine clinical treatments on the VO2–DO2relationship (including catecholamines, PaCO2, Mg2+and hyperglycaemia, as well as patient-specific anatomical variations). The influence of systemic O2transport on cerebral oxygenation is also introduced. This information may help us to refine postoperative management in neonates after the Norwood procedure. Our initial studies mark the end of the beginning, but much is yet explored. Ultimately, the resultant improved systemic and regional O2transport in the early postoperative period may have an important impact on long-term outcomes, thereby improving the quality of life for these vulnerable children. PMID:22457186

  7. Dust transport over the eastern Mediterranean derived from Total Ozone Mapping Spectrometer, Aerosol Robotic Network, and surface measurements

    NASA Astrophysics Data System (ADS)

    Kalivitis, N.; Gerasopoulos, E.; Vrekoussis, M.; Kouvarakis, G.; Kubilay, N.; Hatzianastassiou, N.; Vardavas, I.; Mihalopoulos, N.

    2007-02-01

    Multiyear surface PM10 measurements performed on Crete Island, Greece, have been used in conjunction with satellite (Total Ozone Mapping Spectrometer (TOMS)) and ground-based remote sensing measurements (Aerosol Robotic Network (AERONET)) to enhance our understanding of the evolution of mineral dust events over the eastern Mediterranean. An analysis of southerly air masses at altitudes of 1000 and 3000 m over a 5 year period (2000-2005), showed that dust can potentially arrive over Crete, either simultaneously in the lower free troposphere and inside the boundary layer (vertical extended transport (VET)) or initially into the free troposphere with the heavier particles gradually being scavenged inside the boundary layer (free troposphere transport (FTT)). Both pathways present significant seasonal variations but on an annual basis contribute almost equally to the dust transport in the area. During VET the aerosol index (AI) derived from TOMS was significantly correlated with surface PM10, and in general AI was found to be adequate for the characterization of dust loadings over the eastern Mediterranean on a climatological basis. A significant covariance between PM10 and AOT was observed during VET as well, indicating that AOT levels from AERONET may be estimated by PM10 levels at the surface. Surface measurements are thus crucial for the validation of remote sensing measurements and hence are a powerful tool for the investigation of the impact of aerosols on climate.

  8. A fiber-optic interferometer for in situ measurements of plasma number density in pulsed-power applications

    NASA Astrophysics Data System (ADS)

    Smith, L. M.; Keefer, D. R.; Wright, N. W.

    2003-07-01

    A fiber-optic-based interferometer has been designed, constructed, and applied to plasma measurements in pulsed-power systems. The beam from a 1310 nm solid-state diode laser is coupled into a single-mode fiber and split into two beams, one of which was passed through an acousto-optic modulator to frequency shift the light. Both beams travel through approximately 30 m of fiber, with the probe volume consisting of a short air or vacuum gap in the probe beam fiber where the light is collimated and collected by lenses. The beams are then recombined on a photodiode, producing a time-varying sinusoidal intensity signal that is phase modulated with the presence of a plasma in the probe volume. This configuration allows for remote measurements of plasma electron number density, and is robust with respect to vibration in the plasma source and electromagnetic interference. Tests indicate that phase measurement accuracies of ±0.045 rad corresponding to number density accuracies of ±1.2×1019 m-2 at 1310 nm are achievable with this device. A description of this interferometer, including refinements needed to achieve these accuracies, is presented along with the results of tests performed on a coaxial plasma gun.

  9. Effect of data length and bin numbers on distribution entropy (DistEn) measurement in analyzing healthy aging.

    PubMed

    Udhayakumar, Radhagayathri K; Karmakar, Chandan; Peng Li; Palaniswami, Marimuthu

    2015-08-01

    Complexity analysis of a given time series is executed using various measures of irregularity, the most commonly used being Approximate entropy (ApEn), Sample entropy (SampEn) and Fuzzy entropy (FuzzyEn). However, the dependence of these measures on the critical parameter of tolerance `r' leads to precarious results, owing to random selections of r. Attempts to eliminate the use of r in entropy calculations introduced a new measure of entropy namely distribution entropy (DistEn) based on the empirical probability distribution function (ePDF). DistEn completely avoids the use of a variance dependent parameter like r and replaces it by a parameter M, which corresponds to the number of bins used in the histogram to calculate it. When tested for synthetic data, M has been observed to produce a minimal effect on DistEn as compared to the effect of r on other entropy measures. Also, DistEn is said to be relatively stable with data length (N) variations, as far as synthetic data is concerned. However, these claims have not been analyzed for physiological data. Our study evaluates the effect of data length N and bin number M on the performance of DistEn using both synthetic and physiologic time series data. Synthetic logistic data of `Periodic' and `Chaotic' levels of complexity and 40 RR interval time series belonging to two groups of healthy aging population (young and elderly) have been used for the analysis. The stability and consistency of DistEn as a complexity measure as well as a classifier have been studied. Experiments prove that the parameters N and M are more influential in deciding the efficacy of DistEn performance in the case of physiologic data than synthetic data. Therefore, a generalized random selection of M for a given data length N may not always be an appropriate combination to yield good performance of DistEn for physiologic data. PMID:26738118

  10. Monitoring snowmelt and solute transport at Oslo airport by combining time-lapse electrical resistivity, soil water sampling and tensiometer measurements

    NASA Astrophysics Data System (ADS)

    Bloem, E.; French, H. K.

    2013-12-01

    Monitoring contaminant transport at contaminated sites requires optimization of the configuration of a limited number of samplings points combined with heterogeneous flow and preferential flowpaths. Especially monitoring processes in the unsaturated zone is a major challenge due to the limited volume monitored by for example suction cups and their risk to clog in a highly active degradation zone. To make progress on soil contamination assessment and site characterization there is a strong need to integrate field-sale extensively instrumented tools, with non-invasive (geophysical) methods which provide spatially integrated measurements also in the unsaturated zone. Examples of sites that might require monitoring activities in the unsaturated zone are airports with winter frost where large quantities of de-icing chemicals are used each winter; salt and contaminant infiltration along roads; constructed infiltration systems for treatment of sewerage or landfill seepage. Electrical resistivity methods have proved to be useful as an indirect measurement of subsurface properties and processes at the field-scale. The non-uniqueness of the interpretation techniques can be reduced by constraining the inversion through the addition of independent geophysical measurements along the same profile. Or interpretation and understanding of geophysical images can be improved by the combination with classical measurements of soil physical properties, soil suction, contaminant concentration and temperatures. In our experiment, at the research field station at Gardermoen, Oslo airport, we applied a degradable de-icing chemical and an inactive tracer to the snow cover prior to snowmelt. To study the solute transport processes in the unsaturated zone time-lapse cross borehole electrical resistivity tomography (ERT) measurements were conducted at the same time as soil water samples were extracted at multiple depths with suction cups. Measurements of soil temperature, and soil tension were also carried out during the monitoring period. We present a selection of results from the snowmelt experiments and how the combination of measurement techniques can help interpret and understand the relative importance of the various contributions to the bulk electrical conductivity during snowmelt and solute transport.

  11. MIT commuter common : measuring and improving the transportation footprint of an urban institution

    E-print Network

    Winder, James Ira

    2013-01-01

    This thesis develops a system for observing, visualizing, and understanding transportation behavior at the scale of an urban institution's entire population. In particular, the Massachusetts institute of Technology (MIT) ...

  12. Optical transient grating measurements of micro/nanoscale thermal transport and mechanical properties

    E-print Network

    Eliason, Jeffrey Kristian

    2015-01-01

    The laser-based transient grating technique was used to study phonon mediated thermal transport in bulk and nanostructured semiconductors and surface wave propagation in a monolayer of micron sized spheres. In the transient ...

  13. Measuring total longshore sediment transport with a LISST instrumented mini-sled. 

    E-print Network

    Huchzermeyer, Erick Karl

    2006-04-12

    A surf zone sediment transport study was conducted in Jamaica Beach, Texas, using new oceanographic equipment. A mini-sled was constructed and outfitted with an instrument package that consisted of two velocimeters, one current profiler, three OBS...

  14. Solving Inverse Radiation Transport Problems with Multi-Sensor Data in the Presence of Correlated Measurement and Modeling Errors

    SciTech Connect

    Thomas, Edward V.; Stork, Christopher L.; Mattingly, John K.

    2015-07-01

    Inverse radiation transport focuses on identifying the configuration of an unknown radiation source given its observed radiation signatures. The inverse problem is traditionally solved by finding the set of transport model parameter values that minimizes a weighted sum of the squared differences by channel between the observed signature and the signature pre dicted by the hypothesized model parameters. The weights are inversely proportional to the sum of the variances of the measurement and model errors at a given channel. The traditional implicit (often inaccurate) assumption is that the errors (differences between the modeled and observed radiation signatures) are independent across channels. Here, an alternative method that accounts for correlated errors between channels is described and illustrated using an inverse problem based on the combination of gam ma and neutron multiplicity counting measurements.

  15. An improved model for snowfall measurement using lidar and radar Lidar Backscatter Cross Section ~ number density * Radar Backscatter Cross Section ~ number density * Radar Doppler Velocity ~ f( mass, projected area, air density)

    E-print Network

    Eloranta, Edwin W.

    An improved model for snowfall measurement using lidar and radar Lidar Backscatter Cross Section ~ number density * Radar Backscatter Cross Section ~ number density * Radar 4 24 4 Radar backscatter cross section De '= 3 k2 P(180) * Lidar backscatter cross section Ed

  16. Measurements and modeling of transport and impurity radial profiles in the EXTRAP T2R reversed field pinch

    SciTech Connect

    Kuldkepp, M.; Brunsell, P. R.; Cecconello, M.; Dux, R.; Menmuir, S.; Rachlew, E.

    2006-09-15

    Radial impurity profiles of oxygen in the rebuilt reversed field pinch EXTRAP T2R [P. R. Brunsell et al., Plasma Phys. Control. Fusion 43, 1457 (2001)] have been measured with a multichannel spectrometer. Absolute ion densities for oxygen peak between 1-4x10{sup 10} cm{sup -3} for a central electron density of 1x10{sup 13} cm{sup -3}. Transport simulations with the one-dimensional transport code STRAHL with a diffusion coefficient of 20 m{sup 2} s{sup -1} yield density profiles similar to those measured. Direct measurement of the ion profile evolution during pulsed poloidal current drive suggests that the diffusion coefficient is reduced by a factor {approx}2 in the core but remains unaffected toward the edge. Core transport is not significantly affected by the radial magnetic field growth seen at the edge in discharges without feedback control. This indicates that the mode core amplitude remains the same while the mode eigenfunction increases at the edge.

  17. A strain measurement model using a limited number of sensors for steel beam structures subjected to uncertain loadings

    NASA Astrophysics Data System (ADS)

    Oh, Byung Kwan; Hwang, Jin Woo; Lee, Ji Hoon; Kim, Yousok; Park, Hyo Seon

    2015-11-01

    The maximum stress of a structural member has been extensively adopted as a safety assessment indicator in structural health monitoring. Due to construction errors in the field and changes in the loading conditions during or after construction, it is impractical to accurately predict the location and magnitude of the maximum strain of a member a priori. To avoid the dependency of strain sensing methods on information of the structural and loading conditions, this paper proposes a strain distribution measurement model for steel beam structures subjected to uncertain loadings with uncertainties in magnitudes and shapes. With strains measured from a limited number of sensors, a general form equation of the strain distribution is determined for the estimation of the strain distribution. The performance of the strain distribution measurement model is verified by comparing estimated strain values from the proposed method and measured strains directly from fiber Bragg grating sensors or electrical strain gauges during static loading tests on single- and multi-span beam structures.

  18. Measurement of safety injection fluid transport in a scaled reactor test

    SciTech Connect

    Radcliff, T.D.; Parsons, J.R.; Johnson, W.S.; Ruggles, A.E.

    1999-03-01

    An existing geometric and fluid-fluid scaled facility is applied to investigate the transport of borated safety injection (SI) fluid in the Westinghouse AP600 reactor vessel during a main steam-line rupture (MSLR) event. The AP600 reactor has coaxial injection into the vessel downcomer rather than the cold-leg cross-flow injection typical of operating power reactors. This gas-flow test facility has unique detail in the representation of the SI nozzle-to-core inlet path most important to SI transport. Analysis of the transport phenomena expected in the reactor and the scaled facility, given MSLR conditions, indicates that both buoyancy and turbulent diffusion can have comparable influences on SI transport. It is shown that different reactor-to-experiment velocity ratios are required to scale each phenomenon. Tests are performed to evaluate transient SI fluid concentration at the core inlet using the appropriate velocity ratios to scale buoyancy and diffusion. Two asymmetric loop-flow boundary conditions representative of the MSLR event as well as a symmetric flow condition are applied. While no one test result is fully similar to the expected reactor transport, this ensemble of tests provides data that are valuable for AP600 numerical model benchmarking.

  19. Development of vacuum ultraviolet absorption spectroscopy system for wide measurement range of number density using a dual-tube inductively coupled plasma light source.

    PubMed

    Kuwahara, Akira; Matsui, Makoto; Yamagiwa, Yoshiki

    2012-12-01

    A vacuum ultraviolet absorption spectroscopy system for a wide measurement range of atomic number densities is developed. Dual-tube inductively coupled plasma was used as a light source. The probe beam profile was optimized for the target number density range by changing the mass flow rate of the inner and outer tubes. This system was verified using cold xenon gas. As a result, the measurement number density range was extended from the conventional two orders to five orders of magnitude. PMID:23277970

  20. Development of vacuum ultraviolet absorption spectroscopy system for wide measurement range of number density using a dual-tube inductively coupled plasma light source

    SciTech Connect

    Kuwahara, Akira; Matsui, Makoto; Yamagiwa, Yoshiki

    2012-12-15

    A vacuum ultraviolet absorption spectroscopy system for a wide measurement range of atomic number densities is developed. Dual-tube inductively coupled plasma was used as a light source. The probe beam profile was optimized for the target number density range by changing the mass flow rate of the inner and outer tubes. This system was verified using cold xenon gas. As a result, the measurement number density range was extended from the conventional two orders to five orders of magnitude.

  1. First Measurements of Neutral Atmospheric Cluster and 1–2 nm Particle Number Size Distributions During Nucleation Events

    SciTech Connect

    Jiang, J.; Kuang, C.; Zhao, J.; Chen, M.; Eisele, F. L.; Scheckman, J.; Williams, B. J.; McMurry, P. H.

    2011-02-01

    Recent observations throughout the atmosphere have shown that nucleation occurs frequently (Kulmala et al. 2004). Modeling studies and observations have shown that nucleated particles contribute significantly to concentrations of cloud condensation nuclei (Spracklen et al. 2008), thereby affecting climate (IPCC 2007). Size-resolved measurements extending down to molecular dimensions can provide information on processes that lead to nucleation and would enable development and verification of theories for particle nucleation and growth in the atmosphere and other aerosol systems. This article describes measurements of the complete number size distribution, spanning the size range from vapor molecules and molecular clusters to submicrometer particles, during atmospheric nucleation events. The measurements used two new instruments, the cluster chemical ionization mass spectrometer (Cluster CIMS) and the DEG SMPS. The Cluster CIMS measures neutral molecular clusters from 50 to 900 amu. The DEG SMPS is a scanning mobility particle spectrometer (SMPS) equipped with a diethylene glycol (DEG)-based condensation particle counter (CPC) capable of 1.1 nm mobility diameter particle detection, and overlapping the sizes detected by the Cluster CIMS (Iida et al. 2009; Jiang et al. 2011). The Cluster CIMS distinguishes neutral clusters from ions formed by ion-induced clustering by varying the reaction time for ions with the sampled air (Zhao et al. 2010). It distinguishes clusters from high molecular weight gases by measuring the incremental signal at a specified mass detected during nucleation events. The clusters that were measured in this study contain sulfuric acid, which is known to participate in atmospheric nucleation (Kuang et al. 2008).

  2. Characteristics of submicron aerosol number size distribution and new particle formation events measured in Seoul, Korea, during 2004-2012

    NASA Astrophysics Data System (ADS)

    Park, Minsu; Yum, Seong Soo; Kim, Jong Hwan

    2015-02-01

    The diurnal and seasonal characteristics of the submicron aerosol size distribution measured in Seoul for a long term (2004-2012) were analyzed. The average diurnal variation of aerosol number size distribution showed a single modal distribution but the modal diameter varied around 35 nm and the total aerosol concentration varied diurnally with the maximum during the rush hour. To identify the dominant patterns of the diurnal variation of aerosol number size distribution, the cyclostationary empirical orthogonal function (CSEOF) method was employed. The first CSEOF mode revealed the dominant diurnal pattern that represented an urban life pattern. The principal component (PC) values of the first CSEOF mode showed clear seasonal variation. The PC values were the largest in winter months due to winter monsoon that brought polluted air masses from China, and larger traffic emission amount during the winter season. New particle formation (NPF) events were found to occur on 12.3% of the total measurement days in Seoul when classified with a subjective method. NPF frequency varied seasonally, with the maximum in spring. The second CSEOF mode was found to represent NPF events. A way to identify NPF event days by the CSEOF method was proposed and generally performed well but with some exceptions. The favorable conditions for NPF events in Seoul were found to be low RH, low condensation sink, and low cloud cover, which is consistent with some previous studies. Lastly, the relative contribution of NPF to ultrafine aerosol in Seoul was estimated to be ~32%.

  3. Wind Tunnel Measured Effects on a Twin-Engine Short-Haul Transport Caused by Simulated Ice Accretions: Data Report

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew; Potapczuk, Mark; Ratvasky, Thomas; Laflin, Brenda Gile

    1997-01-01

    The purpose of this report is to release the data from the NASA Langley/Lewis 14 by 22 foot wind tunnel test that examined icing effects on a 1/8 scale twin-engine short-haul jet transport model. Presented in this document are summary data from the major configurations tested. The entire test database in addition to ice shape and model measurements is available as a data supplement in CD-ROM form. Data measured and presented are: wing pressure distributions, model force and moment, and wing surface flow visualization.

  4. Transport of NOx in East Asia identified by satellite and in situ measurements and Lagrangian particle dispersion model simulations

    NASA Astrophysics Data System (ADS)

    Lee, H.-J.; Kim, S.-W.; Brioude, J.; Cooper, O. R.; Frost, G. J.; Kim, C.-H.; Park, R. J.; Trainer, M.; Woo, J.-H.

    2014-03-01

    Nitrogen dioxide (NO2) columns observed from space have been useful in detecting the increase of nitrogen oxides (NOx) emissions in East Asia, particularly China, coinciding with rapid economic growth during the past several decades. NO2 columns retrieved above a particular location reflect a combination of local NOx emissions and transported NOx from upwind sources. In this study, we demonstrate the transport of NOx emitted in East Asia using satellite and surface in situ measurements and Lagrangian particle dispersion model simulations. Enhanced satellite NO2 columns in the Yellow Sea (between China and South Korea) and the East Sea (between South Korea and Japan), and different seasonal variations of NO2 in China, North and South Korea, and Japan, suggest the importance of NOx transport in understanding the local NOx budget. Lagrangian transport model simulations with tracers of different chemical lifetimes identify source-receptor relationships that explain high NO2 over the oceans and springtime peaks in Korea and Japan, with China being the most likely source region. Our results have important implications for studies using satellite NO2 retrievals to derive NOx emissions at local scales in regions adjacent to large sources, such as in East Asia, Europe, and the Eastern U.S.

  5. Measurement of water transport during freezing in mammalian liver tissue: Part II--The use of differential scanning calorimetry.

    PubMed

    Devireddy, R V; Bischof, J C

    1998-10-01

    There is currently a need for experimental techniques to assay the biophysical response (water transport or intracellular ice formation, IIF) during freezing in the cells of whole tissue slices. These data are important in understanding and optimizing biomedical applications of freezing, particularly in cryosurgery. This study presents a new technique using a Differential Scanning Calorimeter (DSC) to obtain dynamic and quantitative water transport data in whole tissue slices during freezing. Sprague-Dawley rat liver tissue was chosen as our model system. The DSC was used to monitor quantitatively the heat released by water transported from the unfrozen cell cytoplasm to the partially frozen vascular/extracellular space at 5 degrees C/min. This technique was previously described for use in a single cell suspension system (Devireddy, et al. 1998). A model of water transport was fit to the DSC data using a nonlinear regression curve-fitting technique, which assumes that the rat liver tissue behaves as a two-compartment Krogh cylinder model. The biophysical parameters of water transport for rat liver tissue at 5 degrees C/min were obtained as Lpg = 3.16 x 10(-13) m3/Ns (1.9 microns/min-atm), ELp = 265 kJ/mole (63.4 kcal/mole), respectively. These results compare favorably to water transport parameters in whole liver tissue reported in the first part of this study obtained using a freeze substitution (FS) microscopy technique (Pazhayannur and Bischof, 1997). The DSC technique is shown to be a fast, quantitative, and reproducible technique to measure dynamic water transport in tissue systems. However, there are several limitations to the DSC technique: (a) a priori knowledge that the biophysical response is in fact water transport, (b) the technique cannot be used due to machine limitations at cooling rates greater than 40 degrees C/min, and (c) the tissue geometric dimensions (the Krogh model dimensions) and the osmotically inactive cell volumes Vb, must be determined by low-temperature microscopy techniques. PMID:10412432

  6. Test-Retest Reliability of a Survey to Measure Transport-Related Physical Activity in Adults

    ERIC Educational Resources Information Center

    Badland, Hannah; Schofield, Grant

    2006-01-01

    The present research details test-retest reliability of a newly developed, telephone-administered TPA survey for adults. This instrument examines barriers, perceptions, and current travel behaviors to place of work/study and local convenience shops. Demonstrated test-retest reliability of the Active Friendly Environments-Transport-Related Physical…

  7. TRANSFORMATION AND TRANSPORT OF SEMI-VOLATILE ORGANIC COMPOUNDS FROM SOIL: MEASURING DICARBOXIMIDES IN A CHAMBER

    EPA Science Inventory

    A laboratory chamber was used to determine transport of a suspected anti-androgenic dicarboximide fungicide, vinclozolin (3,5-dichlorophenyl)-5-methyl-5-vinyl-oxzoli-dine-2,4-dione) and three degradation products from a North Carolina Piedmont aquic hapludult soil following a s...

  8. Comparison of Integrated Radiation Transport Models with TEPC Measurements for the Average Quality Factors in Spaceflights

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Nikjoo, Hooshang; Dicello, John F.; Pisacane, Vincent; Cucinotta, Francis A.

    2007-01-01

    The purpose of this work is to test our theoretical model for the interpretation of radiation data measured in space. During the space missions astronauts are exposed to the complex field of radiation type and kinetic energies from galactic cosmic rays (GCR), trapped protons, and sometimes solar particle events (SPEs). The tissue equivalent proportional counter (TEPC) is a simple time-dependent approach for radiation monitoring for astronauts on board the International Space Station. Another and a newer approach to Microdosimetry is the use of silicon-on-insulator (SOI) technology launched on the MidSTAR-1 mission in low Earth orbit (LEO). In the radiation protection practice, the average quality factor of a radiation field is defined as a function of linear energy transfer (LET), Q(sub ave)(LET). However, TEPC measures the average quality factor as a function of the lineal energy y, Q(sub ave)(y), defined as the average energy deposition in a volume divided by the average chord length of the volume. Lineal energy, y, deviates from LET due to energy straggling, delta-ray escape or entry, and nuclear fragments produced in the detector volume. Monte Carlo track structure simulation was employed to obtain the response of a TEPC irradiated with charged particle for an equivalent site diameter of 1 micron of wall-less counter. The calculated data of the energy absorption in the wall-less counter were compiled for various y values for several ion types at various discrete projectile energy levels. For the simulation of TEPC response from the mixed radiation environments inside a spacecraft, such as, Space Shuttle and International Space Station, the complete microdosimetric TEPC response, f( y, E, Z), were calculated with the Monte Carlo theoretical results by using the first order Lagrangian interpolation for a monovariate function at a given y value (y = 0.1 keV/micron 5000 keV/micron) at any projectile energy level (E = 0.01 MeV/u to 50,000 MeV/u) of each specific radiation type (Z = 1 to 28). Because the anomalous response has been observed at large event sizes in the experiment due to the escape of energy out of sensitive volume by delta-rays and the entry of delta-rays from the high-density wall into the low-density gas-volume cavity, Monte Carlo simulation was also made for the response of a walled-TEPC with wall thickness 2 mm and density 1 g/cm(exp 3). The radius of cavity was set to 6.35 mm and a gas density 7.874 x 10(exp -5) g/cm(exp 3). The response of the walled- and the wall-less counters were compared. The average quality factor Q(sub ave)(y) for trapped protons on STS-89 demonstrated the good agreement between the model calculations and flight TEPC data as shown. Using an integrated space radiation model (this includes the transport codes HZETRN and BRYNTRN, the quantum nuclear interaction model QMSFRG) and the resultant response distribution functions of walled-TEPC from Monte-Carlo track simulations, we compared model calculations with walled-TEPC measurements from NASA missions in LEO and made predictions for the lunar and the Mars missions. The Q(sub ave)(y) values for the trapped or the solar protons ranged from 1.9-2.5. This over-estimates the Qave(LET) values which ranged from 1.4-1.6. Both quantities increase with shield thickness due to nuclear fragmentation. The Q(sub ave)(LET) for the complete GCR spectra was found to be 3.5-4.5, while flight TEPCs measured 2.9-3.4 for Q(sub ave)(y). The GCR values are decreasing with the shield thickness. Our analysis for a proper interpretation of data supports the use of TEPCs for monitoring space radiation environment.

  9. Temperature and number density measurement in non-uniform supersonic flowfields undergoing mixing using toluene PLIF thermometry

    NASA Astrophysics Data System (ADS)

    Gamba, Mirko; Miller, Victor A.; Mungal, M. Godfrey; Hanson, Ronald K.

    2015-08-01

    Single-excitation, dual-band-collection toluene planar laser-induced fluorescence (PLIF) is used to measure temperature and number density (or partial pressure) fields in non-uniform supersonic complex flows in the presence of mixing and compressibility. The study provides a quantitative evaluation of the technique in transverse jets in supersonic crossflow (JISCF). It is found that toluene PLIF is highly effective in visualizing the structure of supersonic flows and that temperature can be accurately inferred with acceptable signal-to-noise ratios (of order 30) even when mixing occurs. The technique was applied to several JISCFs that differ by jet fluid properties with resulting different structures. In the presence of compressibility and mixing, it is found that the PLIF signal is non-unique, a feature that is used to identify the mixing region of the transverse jet. Measurement errors due to camera registration errors have also been quantified. Because of the complexity of the flowfield, it is found that minute misalignment (<0.1 pixels) between the two PLIF images can introduce measurable errors on the order of tens of Kelvins and significant errors in temperature gradients.

  10. Location - Dependent Coronary Artery Diffusive and Convective Mass Transport Properties of a Lipophilic Drug Surrogate Measured Using Nonlinear Microscopy

    PubMed Central

    Keyes, Joseph T.; Simon, Bruce R.; Vande Geest, Jonathan P.

    2013-01-01

    Purpose Arterial wall mass transport properties dictate local distribution of biomolecules or locally delivered dugs. Knowing how these properties vary between coronary artery locations could provide insight into how therapy efficacy is altered between arterial locations. Methods We introduced an indocarbocyanine drug surrogate to the lumens of left anterior descending and right coronary (LADC; RC) arteries from pigs with or without a pressure gradient. Interstitial fluorescent intensity was measured on live samples with multiphoton microscopy. We also measured binding to porcine coronary SMCs in monoculture. Results Diffusive transport constants peaked in the middle sections of the LADC and RC arteries by 2.09 and 2.04 times, respectively, compared to the proximal and distal segments. There was no statistical difference between the average diffusivity value between LADC and RC arteries. The convection coefficients had an upward trend down each artery, with the RC being higher than the LADC by 3.89 times. Conclusions This study demonstrates that the convective and diffusive transport of lipophilic molecules changes between the LADC and the RC arteries as well as along their length. These results may have important implications in optimizing drug delivery for the treatment of coronary artery disease. PMID:23224981

  11. Radon measurements in the lower tropical stratosphere - Evidence for rapid vertical transport and dehydration of tropospheric air

    NASA Technical Reports Server (NTRS)

    Kritz, Mark A.; Rosner, Stefan W.; Kelly, Kenneth K.; Loewenstein, Max; Chan, K. R.

    1993-01-01

    During the tropical experiment of NASA's Stratosphere-Troposphere Exchange Program (STEP), in situ radon and other trace constituent measurements were made aboard a NASA ER-2 high-altitude research aircraft to investigate the mechanisms of irreversible transfers from the troposphere into the tropical stratosphere. Observations made in and downwind of the cirrus shields of three large tropical cyclones and downwind of the cirrus anvil of a large cumulonimbus cloud cluster showed several clear instances of elevated radon activity occurring simultaneously with low total water mixing ratios. These observations are unambiguous evidence of an effective dehydration process, capable of reducing total water vapor mixing ratios to less than 2.5 ppmv, occurring in conjunction with troposphere-to-stratosphere transport and indicate that rapid localized convection, rather than slow regional mean motions, was responsible for the observed transports and associated with the accompanying dehydration. Radon activities measured in regions of active or recent troposphere-to-stratosphere transport were consistent with the 17 pCi/scm mean value needed to support the observed abundance of stratospheric 210 Pb.

  12. Measurements and modeling of water transport and osmoregulation in a single kidney cell using optical tweezers and videomicroscopy

    NASA Astrophysics Data System (ADS)

    Lúcio, A. D.; Santos, R. A.; Mesquita, O. N.

    2003-10-01

    With an optical tweezer installed in our optical microscope we grab a single Madin Darby Canine kidney cell and keep it suspended in the medium without touching the glass substrate or other cells. Since the optically trapped cell remains with a closely round shape, we can directly measure its volume by using videomicroscopy with digital image analysis. We submit this cell to a hyperosmotic shock (up-shock) and video record the process: the cell initially shrinks due to osmotic efflux of water and after a while, due to regulatory volume increase (RVI), an osmoregulation response, it inflates again (water influx) until it reaches a new volume (the regulatory volume VR). In addition to considering standard osmotic water transport, we model RVI using a simple phenomenological model. We obtain an expression for cell volume variation as a function of time that fits very well with our experimental data, where two characteristic times appear naturally: one related to water transport and the other related to RVI. From the fit we obtain water permeability, osmolyte influx rate for RVI, and regulatory volume. With the addition of the hormone vasopressin, water permeability increases while the regulatory volume decreases until inhibition of RVI. In summary, we present a technique to measure directly volume changes of a single isolated kidney cell under osmotic shock and a phenomenological analysis of water transport that takes into account osmoregulation.

  13. Large thermoelectric figure-of-merits from SiGe nanowires by simultaneously measuring electrical and thermal transport properties.

    PubMed

    Lee, Eun Kyung; Yin, Liang; Lee, Yongjin; Lee, Jong Woon; Lee, Sang Jin; Lee, Junho; Cha, Seung Nam; Whang, Dongmok; Hwang, Gyeong S; Hippalgaonkar, Kedar; Majumdar, Arun; Yu, Choongho; Choi, Byoung Lyong; Kim, Jong Min; Kim, Kinam

    2012-06-13

    The strongly correlated thermoelectric properties have been a major hurdle for high-performance thermoelectric energy conversion. One possible approach to avoid such correlation is to suppress phonon transport by scattering at the surface of confined nanowire structures. However, phonon characteristic lengths are broad in crystalline solids, which makes nanowires insufficient to fully suppress heat transport. Here, we employed Si-Ge alloy as well as nanowire structures to maximize the depletion of heat-carrying phonons. This results in a thermal conductivity as low as ?1.2 W/m-K at 450 K, showing a large thermoelectric figure-of-merit (ZT) of ?0.46 compared with those of SiGe bulks and even ZT over 2 at 800 K theoretically. All thermoelectric properties were "simultaneously" measured from the same nanowires to facilitate accurate ZT measurements. The surface-boundary scattering is prominent when the nanowire diameter is over ?100 nm, whereas alloying plays a more important role in suppressing phonon transport for smaller ones. PMID:22548377

  14. On the interpretation of fluctuation and ExB turbulent transport measured by Langmuir probes in fusion plasmas

    SciTech Connect

    Calderon, E.; Hidalgo, C.; Pedrosa, M.A.; Silva, C.

    2004-10-01

    Plasma fluctuations and fluctuation-induced particle fluxes have been investigated in the plasma edge of the TJ-II stellarator using Langmuir probes. Simultaneous measurements of plasma fluctuations carried out by probes located in and out of the probe body sheath show similar results in the normalized level of fluctuations in the ion saturation current. However, floating potential fluctuations measured in the co and counter direction of the magnetic field on the sheath probe body show slight but significant differences. The local radial electrostatic turbulent driven transport measured in and out of the probe body sheath shows consistent results, within the errors bars due to uncertainties in the determination of the effective probe collecting area; the normalized local radial transport to the average ion saturation current (the effective velocity which is not affected by uncertainties in the probe area) show consistent results. These results and previous findings call into question the recent interpretation of probe measurements on the basis of the influence of the probe's pre-sheath zone [B. Labombard, Phys. Plasmas. 9, 1300 (2002)].

  15. Transport characteristics of n-ZnO/p-Si heterojunction as determined from temperature dependent current-voltage measurements

    NASA Astrophysics Data System (ADS)

    Djiokap, S. R. Tankio; Urgessa, Z. N.; Mbulanga, C. M.; Venter, A.; Botha, J. R.

    2016-01-01

    Zinc oxide (ZnO) nanorods have been synthesized by a two-step chemical bath deposition process on silicon substrates having different dopant densities and orientations. Scanning electron microscopy and X-ray diffraction analysis reveal that the orientation of the Si substrate does not affect the orientation, distribution or crystallinity of the nanostructures. The electrical properties of the ZnO/Si heterojunction are also investigated by current-voltage (I-V) measurements. The ideality factor is found to be 2.6 at 295 K, indicating that complex current transport mechanisms are at play. Temperature dependent I-V characteristics have been used to determine the dominant transport mechanism. The experimental results suggest that in the low bias region the current is dominated by a trap assisted multi-step tunneling process.

  16. Development of micro-four-point probe in a scanning tunneling microscope for in situ electrical transport measurement

    SciTech Connect

    Ge, Jian-Feng; Liu, Zhi-Long; Gao, Chun-Lei; Qian, Dong; Liu, Canhua E-mail: jfjia@sjtu.edu.cn; Jia, Jin-Feng E-mail: jfjia@sjtu.edu.cn

    2015-05-15

    Electrons at surface may behave differently from those in bulk of a material. Multi-functional tools are essential in comprehensive studies on a crystal surface. Here, we developed an in situ microscopic four-point probe (4PP) transport measurement system on the basis of a scanning tunneling microscope (STM). In particular, convenient replacement between STM tips and micro-4PPs enables systematic investigations of surface morphology, electronic structure, and electrical transport property of a same sample surface. Performances of the instrument are demonstrated with high-quality STM images, tunneling spectra, and low-noise electrical I-V characteristic curves of a single-layer FeSe film grown on a conductive SrTiO{sub 3} surface.

  17. The Degree of Segmental Aneuploidy Measured by Total Copy Number Abnormalities Predicts Survival and Recurrence in Superficial Gastroesophageal Adenocarcinoma

    PubMed Central

    Davison, Jon M.; Yee, Melissa; Krill-Burger, J. Michael; Lyons-Weiler, Maureen A.; Kelly, Lori A.; Sciulli, Christin M.; Nason, Katie S.; Luketich, James D.; Michalopoulos, George K.; LaFramboise, William A.

    2014-01-01

    Background Prognostic biomarkers are needed for superficial gastroesophageal adenocarcinoma (EAC) to predict clinical outcomes and select therapy. Although recurrent mutations have been characterized in EAC, little is known about their clinical and prognostic significance. Aneuploidy is predictive of clinical outcome in many malignancies but has not been evaluated in superficial EAC. Methods We quantified copy number changes in 41 superficial EAC using Affymetrix SNP 6.0 arrays. We identified recurrent chromosomal gains and losses and calculated the total copy number abnormality (CNA) count for each tumor as a measure of aneuploidy. We correlated CNA count with overall survival and time to first recurrence in univariate and multivariate analyses. Results Recurrent segmental gains and losses involved multiple genes, including: HER2, EGFR, MET, CDK6, KRAS (recurrent gains); and FHIT, WWOX, CDKN2A/B, SMAD4, RUNX1 (recurrent losses). There was a 40-fold variation in CNA count across all cases. Tumors with the lowest and highest quartile CNA count had significantly better overall survival (p?=?0.032) and time to first recurrence (p?=?0.010) compared to those with intermediate CNA counts. These associations persisted when controlling for other prognostic variables. Significance SNP arrays facilitate the assessment of recurrent chromosomal gain and loss and allow high resolution, quantitative assessment of segmental aneuploidy (total CNA count). The non-monotonic association of segmental aneuploidy with survival has been described in other tumors. The degree of aneuploidy is a promising prognostic biomarker in a potentially curable form of EAC. PMID:24454681

  18. Measurement and modelling of reactive transport in geological barriers for nuclear waste containment.

    PubMed

    Xiong, Qingrong; Joseph, Claudia; Schmeide, Katja; Jivkov, Andrey P

    2015-11-11

    Compacted clays are considered as excellent candidates for barriers to radionuclide transport in future repositories for nuclear waste due to their very low hydraulic permeability. Diffusion is the dominant transport mechanism, controlled by a nano-scale pore system. Assessment of the clays' long-term containment function requires adequate modelling of such pore systems and their evolution. Existing characterisation techniques do not provide complete pore space information for effective modelling, such as pore and throat size distributions and connectivity. Special network models for reactive transport are proposed here using the complimentary character of the pore space and the solid phase. This balances the insufficient characterisation information and provides the means for future mechanical-physical-chemical coupling. The anisotropy and heterogeneity of clays is represented using different length parameters and percentage of pores in different directions. Resulting networks are described as mathematical graphs with efficient discrete calculus formulation of transport. Opalinus Clay (OPA) is chosen as an example. Experimental data for the tritiated water (HTO) and U(vi) diffusion through OPA are presented. Calculated diffusion coefficients of HTO and uranium species are within the ranges of the experimentally determined data in different clay directions. This verifies the proposed pore network model and validates that uranium complexes are diffusing as neutral species in OPA. In the case of U(vi) diffusion the method is extended to account for sorption and convection. Rather than changing pore radii by coarse grained mathematical formula, physical sorption is simulated in each pore, which is more accurate and realistic. PMID:26524292

  19. One-dimensional deterministic transport in neurons measured by dispersion-relation phase spectroscopy

    PubMed Central

    Wang, Ru; Wang, Zhuo; Leigh, Joe; Sobh, Nahil; Millet, Larry; Gillette, Martha U.; Levine, Alex J.; Popescu, Gabriel

    2011-01-01

    We studied the active transport of intracellular components along neuron processes with a new method developed in our laboratory, dispersion-relation phase spectroscopy. This method is able to quantitatively map spatially the heterogeneous dynamics of the concentration field of the cargos at submicron resolution without the need for tracking individual components. The results in terms of density correlation function reveal that the decay rate is linear in wavenumber, which is consistent with a narrow Lorentzian distribution of cargo velocity. PMID:21862838

  20. Investigation of VOC Transport in Soil Vapors due to Wind Effects using Models and Measurement

    NASA Astrophysics Data System (ADS)

    Pennell, K. G.; Roghani, M.; Shirazi, E.; Willett, E.

    2014-12-01

    For the past several years, vapor intrusion of volatile organic compounds (VOCs) that emanate from hazardous waste sites has been gaining attention due to adverse health effects and regulatory action. Most studies of VOC vapor intrusion suggest that diffusion is the dominant contaminant transport mechanism, while advection is only considered important near contaminant entry points (i.e. building cracks). This conceptual framework is accurate when above-ground surface features do not promote air flow into (or out of) the ground surface. Recent research related to air flow in the atmospheric boundary layer (ABL) due to wind effects around buildings suggests a need for better understanding how advective transport processes can impact contaminant profiles and vapor intrusion exposure risks. In this study, a numerical model using COMSOL Multiphysics was developed to account for parameters affecting the transport of VOCs from the subsurface into buildings by considering wind effects in the ABL. Model simulations are compared to preliminary laboratory and field data to evaluate the relative importance of wind induced pressure gradients, soil permeability, soil porosity, and soil effective diffusivity on vapor intrusion entry rates. The major goal of this research is to develop an improved conceptual understanding of the vapor intrusion process so that remediation efforts can be better designed and implemented.

  1. The molecular mechanism of nuclear transport revealed by atomic-scale measurements

    PubMed Central

    Hough, Loren E; Dutta, Kaushik; Sparks, Samuel; Temel, Deniz B; Kamal, Alia; Tetenbaum-Novatt, Jaclyn; Rout, Michael P; Cowburn, David

    2015-01-01

    Nuclear pore complexes (NPCs) form a selective filter that allows the rapid passage of transport factors (TFs) and their cargoes across the nuclear envelope, while blocking the passage of other macromolecules. Intrinsically disordered proteins (IDPs) containing phenylalanyl-glycyl (FG)-rich repeats line the pore and interact with TFs. However, the reason that transport can be both fast and specific remains undetermined, through lack of atomic-scale information on the behavior of FGs and their interaction with TFs. We used nuclear magnetic resonance spectroscopy to address these issues. We show that FG repeats are highly dynamic IDPs, stabilized by the cellular environment. Fast transport of TFs is supported because the rapid motion of FG motifs allows them to exchange on and off TFs extremely quickly through transient interactions. Because TFs uniquely carry multiple pockets for FG repeats, only they can form the many frequent interactions needed for specific passage between FG repeats to cross the NPC. DOI: http://dx.doi.org/10.7554/eLife.10027.001 PMID:26371551

  2. Transport coefficients for electrons in water vapor: definition, measurement, and calculation.

    PubMed

    Robson, R E; White, R D; Ness, K F

    2011-02-14

    Comparison of experimental and theoretical transport data for electron swarms in water vapour over a wide range of fields provides a rigorous test of (e(-), H(2)O) scattering cross sections over a correspondingly broad range of energies. That like should be compared with like is axiomatic, but the definition of transport coefficients at high fields, when non-conservative processes are significant, has long been contentious. This paper revisits and distills the most essential aspects of the definition and calculation of transport coefficients, giving numerical results for the drift velocity and ionisation coefficient of electrons in water vapour. In particular, the relationship between the theoretically calculated bulk drift velocities of [K. F. Ness and R. E. Robson, Phys. Rev. A 38, 1446 (1988)] and the experimental "arrival time spectra" drift velocity data of Hasegawa et al. [J. Phys. D 40(8), 2495 (2007)] is established. This enables the Hasegawa et al. data to be reconciliated with the previous literature, and facilitates selection of the best (e(-), H(2)O) cross section set. PMID:21322692

  3. Dual radiotracer measurement of zoobenthos-mediated solute and particle transport in freshwater sediments

    SciTech Connect

    Krezoski, J.R.; Robbins, J.A.; White, D.S.

    1984-09-01

    ..gamma.. spectroscopy methods have been applied to determine the effects of two freshwater benthic macroinvertebrates, on reworking of sediments and the transfer of solutes across the sediment-water interface. Natural lake sediments and overlying water were contained in temperature-regulated rectangular plastic cells. After addition of Stylodrilus (oligochaete worms) and Pontoporeia (crustacean amphipods) to these microcosms, the vertical distribution of Cs-137 (a tracer of particle transport) and Na-22 (a tracer of solute transport) were determined. In cells with Stylodrilus, the Cs-137 layer moved downward at a rate that decreased exponentially with time. In cells with Pontoporeia, Cs-137 activity was smeared downward in time owing to eddy diffusive mixing of sediments over a small range (1-2 cm). In cells without worms, the veneer of Cs active material remained at the interface while the penetration of Na-22 into sediments was consistent with diffusion in free solution with small corrections for sediment porosity and sorption. In cells with live Stylodrilus, penetration of Na-22 within the feeding zone was considerably more rapid. Advective transport arises from the incorporation of Na-22 into pore fluids moved downward as a result of conveyor-belt feeding. In cells with Pontoporeia, De is approximately twice that in control cells. In these cells, Na-22 profiles may be treated theoretically without advection. 47 references, 6 figures, 2 tables.

  4. Optical properties of long-range transported Saharan dust over Barbados as measured by dual-wavelength depolarization Raman lidar measurements

    NASA Astrophysics Data System (ADS)

    Groß, S.; Freudenthaler, V.; Schepanski, K.; Toledano, C.; Schäfler, A.; Ansmann, A.; Weinzierl, B.

    2015-10-01

    Dual-wavelength Raman and depolarization lidar observations were performed during the Saharan Aerosol Long-range Transport and Aerosol-Cloud interaction Experiment in Barbados in June and July 2013 to characterize the optical properties and vertical distribution of long-range transported Saharan dust after transport across the Atlantic Ocean. Four major dust events were studied during the measurements from 15 June to 13 July 2013 with aerosol optical depths at 532 nm of up to 0.6. The vertical aerosol distribution was characterized by a three-layer structure consisting of the boundary layer, the entrainment or mixing layer and the pure Saharan dust layer. The upper boundary of the pure dust layer reached up to 4.5 km in height. The contribution of the pure dust layer was about half of the total aerosol optical depth at 532 nm. The total dust contribution was about 50-70 % of the total aerosol optical depth at 532 nm. The lidar ratio within the pure dust layer was found to be wavelength independent with mean values of 53 ± 5 sr at 355 nm and 56 ± 7 sr at 532 nm. For the particle linear depolarization ratio, wavelength-independent mean values of 0.26 ± 0.03 at 355 nm and 0.27 ± 0.01 at 532 nm have been found.

  5. A nu-space for image correlation spectroscopy: characterization and application to measure protein transport in live cells

    NASA Astrophysics Data System (ADS)

    Potvin-Trottier, Laurent; Chen, Lingfeng; Horwitz, Alan Rick; Wiseman, Paul W.

    2013-08-01

    We introduce a new generalized theoretical framework for image correlation spectroscopy (ICS). Using this framework, we extend the ICS method in time-frequency (?, nu) space to map molecular flow of fluorescently tagged proteins in individual living cells. Even in the presence of a dominant immobile population of fluorescent molecules, nu-space ICS (nICS) provides an unbiased velocity measurement, as well as the diffusion coefficient of the flow, without requiring filtering. We also develop and characterize a tunable frequency-filter for spatio-temporal ICS (STICS) that allows quantification of the density, the diffusion coefficient and the velocity of biased diffusion. We show that the techniques are accurate over a wide range of parameter space in computer simulation. We then characterize the retrograde flow of adhesion proteins (?6- and ?L?2-GFP integrins and mCherry-paxillin) in CHO.B2 cells plated on laminin and intercellular adhesion molecule 1 (ICAM-1) ligands respectively. STICS with a tunable frequency filter, in conjunction with nICS, measures two new transport parameters, the density and transport bias coefficient (a measure of the diffusive character of a flow/biased diffusion), showing that molecular flow in this cell system has a significant diffusive component. Our results suggest that the integrin-ligand interaction, along with the internal myosin-motor generated force, varies for different integrin-ligand pairs, consistent with previous results.

  6. Wind Tunnel Measured Effects on a Twin-Engine Short-Haul Transport Caused by Simulated Ice Accretions

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew; Potapczuk, Mark; Ratvasky, Thomas; Laflin, Brenda Gile

    1996-01-01

    A series of wind tunnel tests were conducted to assess the effects of leading edge ice contamination upon the performance of a short-haul transport. The wind tunnel test was conducted in the NASA Langley 14 by 22 foot facility. The test article was a 1/8 scale twin-engine short-haul jet transport model. Two separate leading edge ice contamination configurations were tested in addition to the uncontaminated baseline configuration. Several aircraft configurations were examined including various flap and slat deflections, with and without landing gear. Data gathered included force measurements via an internal six-component force balance, pressure measurements through 700 electronically scanned wing pressure ports, and wing surface flow visualization measurements. The artificial ice contamination caused significant performance degradation and caused visible changes demonstrated by the flow visualization. The data presented here is just a portion of the data gathered. A more complete data report is planned for publication as a NASA Technical Memorandum and data supplement.

  7. Thermal Transport Characteristics of Human Skin Measured In Vivo Using Ultrathin Conformal Arrays of Thermal Sensors and Actuators

    PubMed Central

    Webb, R. Chad; Pielak, Rafal M.; Bastien, Philippe; Ayers, Joshua; Niittynen, Juha; Kurniawan, Jonas; Manco, Megan; Lin, Athena; Cho, Nam Heon; Malyrchuk, Viktor; Balooch, Guive; Rogers, John A.

    2015-01-01

    Measurements of the thermal transport properties of the skin can reveal changes in physical and chemical states of relevance to dermatological health, skin structure and activity, thermoregulation and other aspects of human physiology. Existing methods for in vivo evaluations demand complex systems for laser heating and infrared thermography, or they require rigid, invasive probes; neither can apply to arbitrary regions of the body, offers modes for rapid spatial mapping, or enables continuous monitoring outside of laboratory settings. Here we describe human clinical studies using mechanically soft arrays of thermal actuators and sensors that laminate onto the skin to provide rapid, quantitative in vivo determination of both the thermal conductivity and thermal diffusivity, in a completely non-invasive manner. Comprehensive analysis of measurements on six different body locations of each of twenty-five human subjects reveal systematic variations and directional anisotropies in the characteristics, with correlations to the thicknesses of the epidermis (EP) and stratum corneum (SC) determined by optical coherence tomography, and to the water content assessed by electrical impedance based measurements. Multivariate statistical analysis establishes four distinct locations across the body that exhibit different physical properties: heel, cheek, palm, and wrist/volar forearm/dorsal forearm. The data also demonstrate that thermal transport correlates negatively with SC and EP thickness and positively with water content, with a strength of correlation that varies from region to region, e.g., stronger in the palmar than in the follicular regions. PMID:25658947

  8. Transport analysis of measured neutron energy spectra in a graphite stack with a collimated deuterium-tritium neutron beam

    SciTech Connect

    Tsechanski, A.; Ofek, R.; Goldfeld, A.; Shani, G.

    1989-02-01

    The Ben-Gurion University measurements of neutron energy spectra in a graphite stack, resulting from the scattering of 14.7-MeV neutrons streaming through a 6-cm-diam collimator in a 121-cm-thick paraffin wall, have been used as a benchmark for the compatability and accuracy of discrete ordinates, P/sub n/, and transport calculations and as a tool for fusion reactor neutronics. The transport analysis has been carried out with the DOT 4.2 discrete ordinates code and with cross sections processed with the NJOY code. Most of the parameters affecting the accuracy of the flux and L system scattering cross sections in the P/sub n/ approximation, the quadrature set employed, and the energy multigroup structure. First, a spectrum calculated with DOT 4.2, with a detector located on the axis of the system, was compared with a spectrum calculated with the MCNP Monte Carlo code, which was a preliminary verification of the DOT 4.2 results. Both calculated spectra were in good agreement. Next, the DOT 4.2 calculations were compared with the measured spectra. The comparison showed that the discrepancies between the measurements and the calculations increase as the distance between the detector and the system axis increases. This trend indicates that when the flux is determined mainly by multiple scatterings, a more divided multigroup structure should be employed.

  9. Studies of Band Structure and Free Carrier Scattering in Transparent Conducting Oxides Based on Combined Measurements of Electron Transport Phenomena

    SciTech Connect

    Kaydanov, V. I.; Coutts, T. J.; Young, D. L.

    2000-10-31

    Experimental methods are discussed for studying band structure, effective mass, and other electronic properties relevant to mobility, including scattering mechanisms, relaxation time, and the influence of grain boundaries (GBs) in polycrystalline transparent conducting oxide (TCO) films. Impedance spectroscopy permits evaluation of the GB potential barrier height and density-of-states. These studies enable an estimate of the limiting mobility achievable for practical transparent conducting oxides to be made. The equipment for measurement of the four transport coefficients is discussed, and examples of its application to films of ZnO, SnO2, and Cd2SnO4 are given.

  10. Low-Speed Stability-and-Control and Ground-Effects Measurements on the Industry Reference High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Kemmerly, Guy T.; Campbell, Bryan A.; Banks, Daniel W.; Yaros, Steven F.

    1999-01-01

    As a part of a national effort to develop an economically feasible High Speed Civil Transport (HSCT), a single configuration has been accepted as the testing baseline by the organizations working in the High Speed Research (HSR) program. The configuration is based on a design developed by the Boeing Company and is referred to as the Reference H (Ref H). The data contained in this report are low-speed stability-and-control and ground-effect measurements obtained on a 0.06 scale model of the Ref H in a subsonic tunnel.

  11. Device fabrication and transport measurements of FinFETs built with 28Si SOI wafers towards donor qubits in silicon

    SciTech Connect

    Lo, Cheuk Chi; Persaud, Arun; Dhuey, Scott; Olynick, Deirdre; Borondics, Ferenc; Martin, Michael C.; Bechtel, Hans A.; Bokor, Jeffrey; Schenkel, Thomas

    2009-06-10

    We report fabrication of transistors in a FinFET geometry using isotopically purified silicon-28 -on-insulator (28-SOI) substrates. Donor electron spin coherence in natural silicon is limited by spectral diffusion due to the residual 29Si nuclear spin bath, making isotopically enriched nuclear spin-free 28Si substrates a promising candidate for forming spin quantum bit devices. The FinFET architecture is fully compatible with single-ion implant detection for donor-based qubits, and the donor spin-state readout through electrical detection of spin resonance. We describe device processing steps and discuss results on electrical transport measurements at 0.3 K.

  12. Calorimetric AC loss measurement of MgB2 superconducting tape in an alternating transport current and direct magnetic field

    NASA Astrophysics Data System (ADS)

    See, K. W.; Xu, X.; Horvat, J.; Cook, C. D.; Dou, S. X.

    2012-11-01

    Applications of MgB2 superconductors in electrical engineering have been widely reported, and various studies have been made to define their alternating current (AC) losses. However, studies on the transport losses with an applied transverse DC magnetic field have not been conducted, even though this is one of the favored conditions in applications of practical MgB2 tapes. Methods and techniques used to characterize and measure these losses have so far been grouped into ‘electrical’ and ‘calorimetric’ approaches with external conditions set to resemble the application conditions. In this paper, we present a new approach to mounting the sample and employ the calorimetric method to accurately determine the losses in the concurrent application of AC transport current and DC magnetic fields that are likely to be experienced in practical devices such as generators and motors. This technique provides great simplification compared to the pickup coil and lock-in amplifier methods and is applied to a long length (˜10 cm) superconducting tape. The AC loss data at 20 and 30 K will be presented in an applied transport current of 50 Hz under external DC magnetic fields. The results are found to be higher than the theoretical predictions because of the metallic fraction of the tape that contributes quite significantly to the total losses. The data, however, will allow minimization of losses in practical MgB2 coils and will be used in the verification of numerical coil models.

  13. A Comparison of Measurements from ATMOS and Instruments Aboard the ER-2 Aircraft: Tracers of Atmospheric Transport and Halogenated Gases

    NASA Technical Reports Server (NTRS)

    Chang, A. Y.; Salawitch, R. J.; Michelsen, H. A.; Gunson, M. R.; Abrams, M. C.; Zander, R.; Rinsland, C. P.; Loewenstein, M.; Podolske, J. R.; Proffitt, M. H.; Margitan, J. J.; Fahey, D. W.; Gao, R.-S.; Kelly, K. K.; Elkins, J. W.; Webster, C. R.; May, R. D.; Chan, K. R.; Abbas, M. M.; Goldman, A.

    1996-01-01

    We compare volume mixing ratio profiles of N2O, O3, NO(y), H2O, CH4, and CO in the mid-latitude lower stratosphere measured by the ATMOS Fourier transform spectrometer on the ATLAS-3 Space Shuttle Mission with in situ measurements acquired from the NASA ER-2 aircraft during Nov 1994. ATMOS and ER-2 observations of (N2O) show good agreement, as do measured correlations of (O3), (NO(y)), (H2O), and (CH4) with (N2O). Thus a consistent measure of the hydrogen (H2O, CH4) content of the lower stratosphere is provided by the two platforms. The similarity of (NO(y)) determined by detection of individual species by ATMOS and the total (NOy) measurement on the ER-2 provides strong corroboration for the accuracy of both techniques. A 25% discrepancy in lower stratospheric (CO) observed by ATMOS and the ER-2 remains unexplained. Otherwise, the agreement for measurements of long-lived tracers demonstrates the ability to combine ATMOS data with in situ observations for quantifying atmospheric transport.

  14. A Comparison of Measurements from ATMOS and Instruments Aboard the ER-2 Aircraft: Tracers of Atmospheric Transport

    NASA Technical Reports Server (NTRS)

    Chang, A. Y.; Salawitch, R. J.; Michelsen, H. A.; Gunson, M. R.; Abrams, M. C.; Zander, R.; Rinsland, C. P.; Loewenstein, M.; Podolske, J. R.; Proffitt, M. H.; Margitan, J. J.; Fahey, D. W.; Gao, R.-S.; Kelly, K. K.; Elkins, J. W.; Webster, C. R.; May, R. D.; Chan, K. R.; Abbas, M. M.; Goldman, A.

    1996-01-01

    We compare volume mixing ratio profiles of N2O, O3, NO(y) H2O, CH4, and CO in the mid-latitude lower stratosphere measured by the ATMOS Fourier transform spectrometer on the ATLAS-3 Space Shuttle Mission with in situ measurements acquired from the NASA ER-2 aircraft during Nov 1994. ATMOS and ER-2 observations of [N2O] show good agreement, as do measured correlations of [O3], [NO(y)], [H2O], and [CH4] with [N2O]. Thus a consistent measure of the hydrogen (H2O, CH4) content of the lower stratosphere is provided by the two platforms. The similarity of [NO(y)] determined by detection of individual species by ATMOS and the total [NO(y)] measurement on the ER-2 provides strong corroboration for the accuracy of both techniques. A 25% discrepancy in lower stratospheric [CO] observed by ATMOS and the ER-2 remains unexplained. Otherwise, the agreement for measurements of long-lived tracers demonstrates the ability to combine ATMOS data with in situ observations for quantifying atmospheric transport.

  15. In situ optical measurement of charge transport dynamics in organic photovoltaics.

    PubMed

    Chow, Philip C Y; Bayliss, Sam L; Lakhwani, Girish; Greenham, Neil C; Friend, Richard H

    2015-02-11

    We present a novel experimental approach which allows extraction of both spatial and temporal information on charge dynamics in organic solar cells. Using the wavelength dependence of the photonic structure in these devices, we monitor the change in spatial overlap between the photogenerated hole distribution and the optical probe profile as a function of time. In a model system we find evidence for a buildup of the photogenerated hole population close to the hole-extracting electrode on a nanosecond time scale and show that this can limit charge transport through space-charge effects under operating conditions. PMID:25585168

  16. Informing Aerosol Transport Models With Satellite Multi-Angle Aerosol Measurements

    NASA Technical Reports Server (NTRS)

    Limbacher, J.; Patadia, F.; Petrenko, M.; Martin, M. Val; Chin, M.; Gaitley, B.; Garay, M.; Kalashnikova, O.; Nelson, D.; Scollo, S.

    2011-01-01

    As the aerosol products from the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR) mature, we are placing greater focus on ways of using the aerosol amount and type data products, and aerosol plume heights, to constrain aerosol transport models. We have demonstrated the ability to map aerosol air-mass-types regionally, and have identified product upgrades required to apply them globally, including the need for a quality flag indicating the aerosol type information content, that varies depending upon retrieval conditions. We have shown that MISR aerosol type can distinguish smoke from dust, volcanic ash from sulfate and water particles, and can identify qualitative differences in mixtures of smoke, dust, and pollution aerosol components in urban settings. We demonstrated the use of stereo imaging to map smoke, dust, and volcanic effluent plume injection height, and the combination of MISR and MODIS aerosol optical depth maps to constrain wildfire smoke source strength. This talk will briefly highlight where we stand on these application, with emphasis on the steps we are taking toward applying the capabilities toward constraining aerosol transport models, planet-wide.

  17. Lateral transport of pesticides from a litchi orchard to an adjacent stream: Measurement and Simulation

    NASA Astrophysics Data System (ADS)

    Streck, T.; Kahl, G.; Ingwersen, J.

    2009-04-01

    In the mountainous areas of northern Thailand, human population growth and migration from the lowlands have increased the pressure on agricultural systems. This has led to intensified agriculture, which is accompanied by the expansion of farmland into ever more vulnerable areas and increased application of agrochemicals. To investigate pesticide transport to surface water and to identify the flow components contributing to it, we installed two discharge gauges with automatic water samplers in a stream close to a 2-ha litchi orchard. In two years (between June and September) we applied methomyl, and in one year additionally chlorothalonil, to the orchard and monitored water fluxes and pesticide concentrations in the stream water. A multiple compartment model was developed to evaluate and interpret the field data and to test hypotheses based on the experiments. The model assumes that water flow and solute transport occur in two domains: a fracture domain characterized by rapid, preferential flow and a matrix domain in which processes are slow. The model was tested against discharge and pesticide data from the downstream gauging station. Our results show that the investigated soil is very susceptible to pesticide losses by surface runoff and preferential interflow. More than 10% of the pesticide mass applied reached the stream and preferential interflow contributed most to the pesticide peaks. Matrix and groundwater flow were unimportant. The model was found to be a valuable addition to the experiments because it helped to better understand the observed data. Besides, it could be used to fill data gaps in the experimental studies.

  18. Erosion of upland hillslope soil organic carbon: Coupling field measurements with a sediment transport model

    E-print Network

    Heimsath, Arjun M.

    Erosion of upland hillslope soil organic carbon: Coupling field measurements with a sediment soil C measurements to quantify the erosion and temporal storage of soil organic carbon (SOC) within perturbation (Tennessee Valley (TV)) versus clay-rich soil creep (Black Diamond (BD)). The average SOC erosion

  19. Assessment of Quality Assurance Measures for Radioactive Material Transport Packages not Requiring Competent Authority Design Approval - 13282

    SciTech Connect

    Komann, Steffen; Groeke, Carsten; Droste, Bernhard

    2013-07-01

    The majority of transports of radioactive materials are carried out in packages which don't need a package design approval by a competent authority. Low-active radioactive materials are transported in such packages e.g. in the medical and pharmaceutical industry and in the nuclear industry as well. Decommissioning of NPP's leads to a strong demand for packages to transport low and middle active radioactive waste. According to IAEA regulations the 'non-competent authority approved package types' are the Excepted Packages and the Industrial Packages of Type IP-1, IP-2 and IP-3 and packages of Type A. For these types of packages an assessment by the competent authority is required for the quality assurance measures for the design, manufacture, testing, documentation, use, maintenance and inspection (IAEA SSR 6, Chap. 306). In general a compliance audit of the manufacturer of the packaging is required during this assessment procedure. Their regulatory level in the IAEA regulations is not comparable with the 'regulatory density' for packages requiring competent authority package design approval. Practices in different countries lead to different approaches within the assessment of the quality assurance measures in the management system as well as in the quality assurance program of a special package design. To use the package or packaging in a safe manner and in compliance with the regulations a management system for each phase of the life of the package or packaging is necessary. The relevant IAEA-SSR6 chap. 801 requires documentary verification by the consignor concerning package compliance with the requirements. (authors)

  20. Measurements of stratospheric carbon dioxide and water vapor at northern midlatitudes: Implications for troposphere-to-stratosphere transport

    SciTech Connect

    Boering, K.A.; Wofsy, S.C.; Daube, B.C. Jr.

    1995-10-15

    Simultaneous in situ measurements of CO{sub 2} and water vapor in the lower stratosphere were obtained in November 1992 and May 1993 up to 21 km at midlatitudes. Seasonal changes in both species were observed up to pressure-altitudes of 19 km ({approximately}440K), a result of vertical propagation of seasonal oscillations in CO{sub 2} and H{sub 2}O mixing ratios for air entering the stratosphere in the tropics followed by horizontal transport to midlatitudes. The inferred phase difference between their seasonal cycles at the tropical tropopause (2 months) remained coherent at midlatitudes, although the amplitudes were reduced, implying a mean transport time of 4-6 months from the tropical tropopause ({approximately} 16 km) to {approximately}18.5-19 km at midlatitudes in both November and May. The measurements indicate that air enters the stratosphere throughout the year and suggest that vertical propagation of the seasonal minimum in water vapor, rather than deep convective overshoot, is both sufficient and necessary to explain the minimum in water ({open_quotes}hygropause{close_quotes}) observed several kilometers above the tropopause. 32 refs., 3 figs.

  1. Designing a system for measuring the flow of material transported on belts using ultrasonic sensors

    NASA Astrophysics Data System (ADS)

    Mihu?, N. M.

    2015-11-01

    Excavation tailings (scraping) and extracting the useful (lignite) in surface mine pits in Mining Basin Oltenia is achieved with technological lines of excavation - transport - dump of high productivity. A correlation of working capacity of the main components of technological lines (motor rotor, high capacity transport, car dumps) is necessary for economic reasons on electricity consumption. To achieve experience in the process was chosen excavator SRS 1400 from South Jilt career in the CET Turceni. The question of coal excavated volume has a great importance in the mine pits. At the excavation is desired a density estimate for each machine production tracking, cost estimation and tracking product unit profitability of each band on various sections zones. Permanent display size excavated volume snapshots in the excavator's cabin permits to track tape loading, eliminating unproductive times and information management to determine profitability. Another important requirement is closing the loop of the machine drive system of an excavator for a uniform deposition of carbon on the strip, thus achieving automatic control of the loading belt. Such equipment is important for the system dispatching in surface mine pits. Through a system of three ultrasound transducers to determine the smart instant of coal excavated section which, coupled with the tape speed, integrated over time will determine the amount of excavated coal. The basis of the system developed is a device for determining the volume and quantity of coal excavated acting on the march and optimize the system speed excavator working order. The device is designed primarily following the careers of lignite production: rotor excavators, rubber conveyor belts and dump facilities. Newly developed system aims to achieve the following determines: the optimum energy excavation depending on the nature of excavated material - lignite, shale, clay, etc., economic times to use the excavator bucket teeth rotor, energy optical regime to rubber belt conveyors, eliminate damage to the plant by conveyor belt breakage detection or tread and eliminating time and energy losses by limiting reproductive idle, monitoring the amount of coal excavated, control power consumption. Systems in general and particularly automated systems cannot be designed without taking into account their degree of effectiveness, compliance with minimum consumption of time, energy and materials, insofar as they are requested and used all the resources it has, at minimum cost production, etc. For this reason any matter of calculation, design, analysis and operation of transport systems continuously subordinate requirements optimality.

  2. Low-altitude wind measurements from wide-body jet transports

    NASA Technical Reports Server (NTRS)

    Dunham, R. E., Jr.

    1982-01-01

    For a 2-week period in the spring of 1977, data were collected onboard wide-body jet transports for the determination of winds and wind shear during landings and take-offs. The data represent about 640 take-offs or landings at 14 airports in Europe and the United States. Analysis of the wind-shear data indicates that shears of a given value are equally likely to occur at any altitude in the lower 1400-ft section of the atmosphere. Analysis of the data indicates that low shears (plus or minus .033 knot/per ft) have a 67-percent chance of occurrence during a landing or take-off, while higher values (plus or minus 0.15 knot/per ft) have a 0.5-percent chance of occurrence. A determination of the duration of a given shear was not made.

  3. Measurement of Fast Electron Transport by Lower Hybrid Modulation Experiments in Alcator C-Mod

    SciTech Connect

    Schmidt, A. E.; Bonoli, P. T.; Parker, R.; Porkolab, M.; Wallace, G.; Wright, J. C.; Wilson, J. R.; Harvey, R. W.; Smirnov, A. P.

    2009-11-26

    The Lower Hybrid Current Drive (LHCD) system on Alcator C-Mod can produce spectra with a wide range of peak parallel refractive index (n{sub parallel}). An experiment in which LH power is square-wave modulated on a time scale much faster than the current relaxation time does not significantly alter the poloidal magnetic field inside the plasma and thus allows for realistic modeling and consistent plasma conditions for different ny spectra. Boxcar binning of hard x-rays during LH power modulation allows for time resolution sufficient to resolve the build-up, steady-state, and slowing-down of fast electrons. A transport model built in Matlab has been used to determine a fast electron pinch velocity for a high-n{sub parallel} case of 1-2 m/s.

  4. Transport Experiments

    NASA Technical Reports Server (NTRS)

    Hall, Timothy M.; Wuebbles, Donald J.; Boering, Kristie A.; Eckman, Richard S.; Lerner, Jean; Plumb, R. Alan; Rind, David H.; Rinsland, Curtis P.; Waugh, Darryn W.; Wei, Chu-Feng

    1999-01-01

    MM II defined a series of experiments to better understand and characterize model transport and to assess the realism of this transport by comparison to observations. Measurements from aircraft, balloon, and satellite, not yet available at the time of MM I [Prather and Remsberg, 1993], provide new and stringent constraints on model transport, and address the limits of our transport modeling abilities. Simulations of the idealized tracers the age spectrum, and propagating boundary conditions, and conserved HSCT-like emissions probe the relative roles of different model transport mechanisms, while simulations of SF6 and C02 make the connection to observations. Some of the tracers are related, and transport diagnostics such as the mean age can be derived from more than one of the experiments for comparison to observations. The goals of the transport experiments are: (1) To isolate the effects of transport in models from other processes; (2) To assess model transport for realistic tracers (such as SF6 and C02) for comparison to observations; (3) To use certain idealized tracers to isolate model mechanisms and relationships to atmospheric chemical perturbations; (4) To identify strengths and weaknesses of the treatment of transport processes in the models; (5) To relate evaluated shortcomings to aspects of model formulation. The following section are included:Executive Summary, Introduction, Age Spectrum, Observation, Tropical Transport in Models, Global Mean Age in Models, Source-Transport Covariance, HSCT "ANOY" Tracer Distributions, and Summary and Conclusions.

  5. Measurements of Free-Space Oscillating Pressures Near Propellers at Flight Mach Numbers to 0.72

    NASA Technical Reports Server (NTRS)

    Kurbjun, Max C; Vogeley, Arthur W

    1958-01-01

    In the course of a short flight program initiated to check the theory of Garrick and Watkins (NACA rep. 1198), a series of measurements at three stations were made of the oscillating pressures near a tapered-blade plan-form propeller and rectangular-blade plan form propeller at flight Mach numbers up to 0.72. In contradiction to the results for the propeller studied in NACA rep. 1198, the oscillating pressures in the plane ahead of the propeller were found to be higher than those immediately behind the propeller. Factors such as variation in torque and thrust distribution, since the blades of the present investigation were operating above their design forward speed, may account for this contradiction. The effect of blade plan form shows that a tapered-blade plan-form propeller will produce lower sound-pressure levels than a rectangular-blade plan-form propeller for the low blade-passage harmonics (the frequencies where structural considerations are important) and produce higher sound-pressure levels for the higher blade-passage harmonics (frequencies where passenger comfort is important).

  6. Triaxial creep measurements on rock salt from the Jennings dome, Louisiana, borehole LA-1, core {number_sign}8

    SciTech Connect

    Wawersik, W.R.; Zimmerer, D.J.

    1994-05-01

    Tejas Power Company requested that facilities in the Rock Mechanics Laboratory at Sandia National Laboratories be used to assess the time-dependent properties of rock salt from the Jennings dome in Acadia Parish, Louisiana. Nominally 2.5-inch diameter slat core from borehole LA-1, core 8 (depth 3924.8 to 3837.8 ft; 1196.8--1197.1 m) was provided to accomplish two tasks: (1) Using the smallest possible number of experiments, evaluate the tendency of Jennings salt to undergo time-dependent deformation (creep) under constant applied stresses, and compare the creep of Jennings salt with creep data for rock salt from other locations. (2) Assess the applicability of published laboratory-derived creep properties for rock salt from several bedded and domal sites in finite element analyses concerning the design of new gas storage caverns in the Jennings dome. The characterization of Jennings salt followed the same strategy that was applied in earlier laboratory experiments on core from the Moss Bluff dome near Houston, Texas. This report summarizes the relevant details of five creep experiments on a sample from depth 3927.5 ft, the results obtained, and how these results compared with laboratory creep measurements gathered on rock salt from other locations including the West Hackberry, Bryan Mound and Moss Bluff domes. The report also considers the estimates of specific creep parameters commonly used in numerical engineering design analyses.

  7. The measurement of electron number density in helium micro hollow gas discharge using asymmetric He I lines

    NASA Astrophysics Data System (ADS)

    Jovovi?, J.; Šišovi?, N. M.

    2015-09-01

    The electron number density N e in helium micro hollow gas discharge (MHGD) is measured by means of optical emission spectroscopy (OES) techniques. The structure of MHGD is a gold-alumina-gold sandwich with 250 ?m alumina thickness and 100 ?m diameter hole. The electron temperature T e and gas temperature T g in the discharge is determined using the relative intensity of He I lines and {{\\text{N}}2}+?ft({{\\text{B}}2}?\\text{u}+- {{X}2}?\\text{g}+\\right) R branch lines in the frame of BP technique, respectively. The simple procedure based on spectral line broadening theory was developed in MATLAB to generate synthetic neutral line asymmetric profiles. The synthetic profiles were compared with an experimental He I 447.1?nm and He I 492.2?nm line to obtain N e from the centre of a micro hollow gas discharge (MHGD) source in helium. The N e results were compared with N e values obtained from the forbidden-to-allowed (F/A) intensity ratio technique. The comparison confirmed higher N e determined using a F/A ratio due to large uncertainty of the method. Applying the fitting formula for a He I 492.2?nm line derived from computer simulation (CS) gives the same N e values as the one determined using the MATLAB procedure in this study. The dependence of N e on gas pressure and electric current is investigated as well.

  8. Advantages of measuring changes in the number of viable parasites in murine models of experimental cutaneous leishmaniasis.

    PubMed Central

    Hill, J O; North, R J; Collins, F M

    1983-01-01

    Previously published studies of experimental cutaneous leishmaniasis in the mouse have relied almost exclusively on measuring changes in lesion size to follow the course of the infection. The purposes of the studies reported here were to develop a technique to quantitate the number of viable organisms in the tissues and to use the technique to follow the development and resolution of the primary infection as well as the development of acquired resistance to Leishmania tropica in a resistant (C3H/He) and a susceptible (BALB/c) mouse strain. It was found that individual L. tropica amastigotes derived from infected tissues would transform to promastigotes and repeatedly divide to form discrete, countable colonies on rabbit blood agar. The plating efficiency was approximately 88%. Using the blood agar plating technique to quantitate the organism against time of the infection, we obtained data that suggest that acquired resistance develops in C3H/He mice earlier than is suggested by reduction in lesion size. In addition, although this resistance eliminates the parasites from the primary lesion in 10 weeks, 1,000 to 10,000 parasites persist for months in the lymph node draining the lesion site. In these studies, we found no evidence of acquired resistance in the susceptible BALB/c mice. The organism grows progressively, and the infection can disseminate to the spleen within 2 weeks. These studies illustrate the advantages of quantitating viable parasites in studies of immunity in cutaneous leishmaniasis. PMID:6840835

  9. A Bayesian Approach for Reconstructing the Past Ocean Circulation from a Limited Number of Sediment-Core Radiocarbon Measurements

    NASA Astrophysics Data System (ADS)

    Primeau, F.

    2014-12-01

    Paleoceanographers are faced with the problem of making inferences about the ventilation of the ocean in the past from localized benthic and planktonic radiocarbon measurements obtained from a small number of sediment cores, which leads to an underdetermined problem. With the goal of moving beyond testing the null hypothesis that the sediment core data are consistent with the modern circulation we seek to reconstruct the most probable paleocirculation based on our knowledge of ocean dynamics and available constraints from sediment-core radiocarbon records. We propose a Bayesian inversion approach in which we use a modern circulation estimate constrained by modern radiocarbon data to define the mean of the prior probability distribution for the unknown paleocirculation. The approach resolves the indeterminacy of the inverse problem by choosing a paleocirculation that is minimally different from the modern circulation while still being consistent with the available sediment-core radiocarbon records. In this talk we will present the general formulation of the method as well as various approximations to reduce the computational challenge.

  10. Characteristics of spot-market rate indexes for truckload transportation

    E-print Network

    Bignell, Andrew (Andrew Souglas)

    2013-01-01

    In the truckload transportation industry in the United States, a number of indexes are published that attempt to measure changes in rates, but no single index has emerged as an industry standard. Industry participants, ...

  11. Laser-Induced Fluorescence Measurements of Translational Temperature and Relative Cycle Number by use of Optically Pumped Trace-Sodium Vapor

    NASA Technical Reports Server (NTRS)

    Dobson, Chris C.

    1998-01-01

    Sodium fluorescence induced by a narrow bandwidth tunable laser has been used to measure temperature, pressure, axial velocity and species concentrations in wind tunnels, rocket engine exhausts and the upper atmosphere. Optical pumping of the ground states of the sodium, however, can radically alter the shape of the laser induced fluorescence excitation spectrum, complicating such measurements. Here a straightforward extension of rate equations originally proposed to account for the features of the pumped spectrum is to make temperature measurements from spectra taken in pumped vapor. Also determined from the spectrum is the relative fluorescence cycle number, which has application to measurement of diffusion rate and transverse flow velocity. The accuracy of both the temperature and cycle-number measurements is comparable with that of temperature measurements made in the absence of pumping.

  12. Laser-Induced Fluorescence Measurements of Translational Temperature and Relative Cycle Number by use of Optically Pumped Trace-Sodium Vapor

    NASA Technical Reports Server (NTRS)

    Dobson, Chris C.

    1999-01-01

    Sodium fluorescence induced by a narrow-bandwidth tunable laser has been used to measure temperature, pressure, axial velocity, and species concentrations in wind tunnels, rocket engine exhausts, and the upper atmosphere. Optical pumping of the ground states of the sodium, however, can radically alter the shape of the laser-induced fluorescence excitation spectrum, complicating such measurements. Here a straightforward extension of rate equations originally proposed to account for the features of the pumped spectrum is used to make temperature measurements from spectra taken in pumped vapor. Also determined from the spectrum is the relative fluorescence cycle number, which has application to measurement of diffusion rate and transverse flow velocity, The accuracy of both the temperature and the cycle-number measurements is comparable with that of temperature measurements made in the absence of pumping.

  13. Numerical modeling and experimental measurements of water spray impact and transport over a cylinder.

    SciTech Connect

    Avedisian, C. T.; Presser, Cary; DesJardin, Paul Edward; Hewson, John C.; Yoon, Sam Sukgoo

    2005-03-01

    This study compares experimental measurements and numerical simulations of liquid droplets over heated (to a near surface temperature of 423 K) and unheated cylinders. The numerical model is based on an unsteady Reynolds-averaged Navier-Stokes (RANS) formulation using a stochastic separated flow (SSF) approach for the droplets that includes submodels for droplet dispersion, heat and mass transfer, and impact on a solid surface. The details of the droplet impact model are presented and the model is used to simulate water spray impingement on a cylinder. Computational results are compared with experimental measurements using phase Doppler interferometry (PDI).

  14. Characterization of aluminum oxide tunnel barriers by combining transport measurements and transmission electron microscopy imaging

    SciTech Connect

    Aref, T.; Averin, A.; Nguyend, H. Q.; Pekola, J. P.; Dijken, S. van; Yao, L. D.; Ferring, A.; Koberidze, M.; Nieminen, R. M.

    2014-08-21

    We present two approaches for studying the uniformity of a tunnel barrier. The first approach is based on measuring single-electron and two-electron tunneling in a hybrid single-electron transistor. Our measurements indicate that the effective area of a conduction channel is about one order of magnitude larger than predicted by theoretical calculations. With the second method, transmission electron microscopy, we demonstrate that variations in the barrier thickness are a plausible explanation for the larger effective area and an enhancement of higher order tunneling processes.

  15. 77 FR 11394 - Transportation Conformity Rule: MOVES Regional Grace Period Extension

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-27

    ...Docket is (202) 566-1742. FOR FURTHER INFORMATION CONTACT: Meg Patulski, State Measures and Transportation Planning Center...fax number: (734) 214-4052; email address: patulski.meg@epa.gov; or Astrid Larsen, State Measures and...

  16. Flight Measurements of Average Skin-Friction Coefficients on a Parabolic Body of Revolution (NACA RM-10) at Mach Numbers from 1.0 to 3.7

    NASA Technical Reports Server (NTRS)

    Loposer, J. Dan; Rumsey, Charles B.

    1954-01-01

    Measurement of average skin-friction coefficients have been made on six rocket-powered free-flight models by using the boundary-layer rake technique. The model configuration was the NACA RM-10, a 12.2-fineness-ratio parabolic body of revolution with a flat base. Measurements were made over a Mach number range from 1 to 3.7, a Reynolds number range 40 x 10(exp 6) to 170 x 10(exp 6) based on length to the measurement station, and with aerodynamic heating conditions varying from strong skin heating to strong skin cooling. The measurements show the same trends over the test ranges as Van Driest's theory for turbulent boundary layer on a flat plate. The measured values are approximately 7 percent higher than the values of the flat-plate theory. A comparison which takes into account the differences in Reynolds number is made between the present results and skin-friction measurements obtained on NACA RM-10 scale models in the Langley 4- by 4-foot supersonic pressure tunnel, the Lewis 8- by 6-foot supersonic tunnel, and the Langley 9-inch supersonic tunnel. Good agreement is shown at all but the lowest tunnel Reynolds number conditions. A simple empirical equation is developed which represents the measurements over the range of the tests.

  17. Wicking nanopillar arrays with dual roughness for selective transport and fluorescence measurements.

    PubMed

    Charlton, Jennifer J; Lavrik, Nickolay; Bradshaw, James A; Sepaniak, Michael J

    2014-10-22

    Silicon nanopillars are important building elements for innovative nanoscale systems with unique optical, wetting, and chemical separation functionalities. However, technologies for creating expansive pillars arrays on the submicron scale are often complex and with practical time, cost, and method limitations. Herein we demonstrate the rapid fabrication of nanopillar arrays using the thermal dewetting of Pt films with thicknesses in the range from 5 to 19 nm followed by anisotropic reactive ion etching (RIE) of the substrate materials. A second level of roughness on the sub-30 nm scale is added by overcoating the silicon nanopillars with a conformal layer of porous silicon oxide (PSO) using room temperature plasma enhanced chemical vapor deposition (PECVD). This technique produced environmentally conscious, economically feasible, expansive nanopillar arrays with a production pathway scalable to industrial demands. The arrays were systematically analyzed for size, density, and variability of the pillar dimensions. We show that these stochastic arrays exhibit rapid wicking of various fluids and, when functionalized with a physiosorbed layer of silicone oil, act as a superhydrophobic surface. We also demonstrate high brightness fluorescence and selective transport of model dye compounds on surfaces of the implemented nanopillar arrays with two-tier roughness. The demonstrated combination of functionalities creates a platform with attributes inherently important for advanced separations and chemical analysis. PMID:25247442

  18. Temperature-controlled quartz crystal microbalance measurements on Space Transport System (STS-2)

    NASA Technical Reports Server (NTRS)

    Fountain, J. A.

    1983-01-01

    The purpose of the Temperature-Controlled Quartz Crystal Microbalance (TQCM) system on STS-2 was to measure condensible molecular flux in the payload bay of the Space Shuttle as a function of temperature, direction, and time. Five quartz crystal microbalance sensors were located in the IECM to measure molecular adsorption in each of the Orbiter axes, +X (fore), -X (aft), +Y (starboard), -Y (port), and -Z (up, perpendicular to payload bay). The temperature of each sensor was controlled by a thermoelectric device so contamination could be measured as a function of four preset temperatures: +30, 0, -30, and -60 C. When orbital altitude was reached, the TQCM sensors began their orbital measuring cycle routine. The sensors were commanded to 80 C for 30 min, which was used as an initial clean-up. They were then stepped through a program of 2-nr collection periods at each temperature with a 30-min, 80 C period between each collection period. The collection periods progressed in descending order from +30 to -60 C and, then the cycle was repeated. Since the STS-2 orbital phase lasted approximately 53 hrs, the TQCM system completed four cycles and was in the fifth when the mission was terminated.

  19. Mean field limit for bosons with compact kernels interactions by Wigner measures transportation

    SciTech Connect

    Liard, Quentin Pawilowski, Boris

    2014-09-15

    We consider a class of many-body Hamiltonians composed of a free (kinetic) part and a multi-particle (potential) interaction with a compactness assumption on the latter part. We investigate the mean field limit of such quantum systems following the Wigner measures approach. We prove in particular the propagation of these measures along the flow of a nonlinear (Hartree) field equation. This enhances and complements some previous results of the same type shown in Z. Ammari and F. Nier and Fröhlich et al. [“Mean field limit for bosons and propagation of Wigner measures,” J. Math. Phys. 50(4), 042107 (2009); Z. Ammari and F. Nier and Fröhlich et al., “Mean field propagation of Wigner measures and BBGKY hierarchies for general bosonic states,” J. Math. Pures Appl. 95(6), 585–626 (2011); Z. Ammari and F. Nier and Fröhlich et al., “Mean-field- and classical limit of many-body Schrödinger dynamics for bosons,” Commun. Math. Phys. 271(3), 681–697 (2007)].

  20. Droplet-based microfluidic platform for measurement of rapid erythrocyte water transport.

    PubMed

    Jin, Byung-Ju; Esteva-Font, Cristina; Verkman, A S

    2015-08-21

    Cell membrane water permeability is an important determinant of epithelial fluid secretion, tissue swelling, angiogenesis, tumor spread and other biological processes. Cellular water channels, aquaporins, are important drug targets. Water permeability is generally measured from the kinetics of cell volume change in response to an osmotic gradient. Here, we developed a microfluidic platform in which cells expressing a cytoplasmic, volume-sensing fluorescent dye are rapidly subjected to an osmotic gradient by solution mixing inside a ~0.1 nL droplet surrounded by oil. The solution mixing time was <10 ms. Osmotic water permeability was deduced from a single, time-integrated fluorescence image of an observation area in which the time after mixing was determined through spatial position. Water permeability was accurately measured in aquaporin-expressing erythrocytes with half-times for osmotic equilibration down to <50 ms. Compared with conventional water permeability measurements using costly stopped-flow instrumentation, the microfluidic platform here utilizes sub-microliter blood sample volume, does not suffer from mixing artifacts, and replaces challenging kinetic measurements by single image capture using a standard laboratory fluorescence microscope. PMID:26159099

  1. In-situ Measurements of Colloid Transport and Retention Using Synchroton X-ray Fluorescence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The physics regarding the retention and mobilization of colloids in saturated and unsaturated conditions remains poorly understood, partially due to the inability to measure colloid concentrations in-situ. In this study, we attached Cd+2 ions to clay colloids, and used synchrotron x-rays to cause th...

  2. Correcting acoustic Doppler current profiler discharge measurements biased by sediment transport

    USGS Publications Warehouse

    Mueller, D.S.; Wagner, C.R.

    2007-01-01

    A negative bias in discharge measurements made with an acoustic Doppler current profiler (ADCP) is attributed to the movement of sediment on or near the streambed, and is an issue widely acknowledged by the scientific community. The integration of a differentially corrected global positioning system (DGPS) to track the movement of the ADCP can be used to avoid the systematic bias associated with a moving bed. DGPS, however, cannot provide consistently accurate positions because of multipath errors and satellite signal reception problems on waterways with dense tree canopy along the banks, in deep valleys or canyons, and near bridges. An alternative method of correcting for the moving-bed bias, based on the closure error resulting from a two-way crossing of the river, is presented. The uncertainty in the mean moving-bed velocity measured by the loop method is shown to be approximately 0.6cm/s. For the 13 field measurements presented, the loop method resulted in corrected discharges that were within 5% of discharges measured utilizing DGPS to compensate for moving-bed conditions. ?? 2007 ASCE.

  3. Kinetic dissolution of carbonates and Mn oxides in acidic water: Measurement of in situ field rates and reactive transport modeling

    USGS Publications Warehouse

    Brown, J.G.; Glynn, P.D.

    2003-01-01

    The kinetics of carbonate and Mn oxide dissolution under acidic conditions were examined through the in situ exposure of pure phase samples to acidic ground water in Pinal Creek Basin, Arizona. The average long-term calculated in situ dissolution rates for calcite and dolomite were 1.65??10-7 and 3.64??10-10 mmol/(cm2 s), respectively, which were about 3 orders of magnitude slower than rates derived in laboratory experiments by other investigators. Application of both in situ and lab-derived calcite and dolomite dissolution rates to equilibrium reactive transport simulations of a column experiment did not improve the fit to measured outflow chemistry: at the spatial and temporal scales of the column experiment, the use of an equilibrium model adequately simulated carbonate dissolution in the column. Pyrolusite (MnO2) exposed to acidic ground water for 595 days increased slightly in weight despite thermodynamic conditions that favored dissolution. This result might be related to a recent finding by another investigator that the reductive dissolution of pyrolusite is accompanied by the precipitation of a mixed Mn-Fe oxide species. In PHREEQC reactive transport simulations, the incorporation of Mn kinetics improved the fit between observed and simulated behavior at the column and field scales, although the column-fitted rate for Mn-oxide dissolution was about 4 orders of magnitude greater than the field-fitted rate. Remaining differences between observed and simulated contaminant transport trends at the Pinal Creek site were likely related to factors other than the Mn oxide dissolution rate, such as the concentration of Fe oxide surface sites available for adsorption, the effects of competition among dissolved species for available surface sites, or reactions not included in the model.

  4. From computing with numbers to computing with words-from manipulation of measurements to manipulation of perceptions

    NASA Astrophysics Data System (ADS)

    Zadeh, Lotfi A.

    2001-06-01

    Computing, in its usual sense, is centered on manipulation of numbers and symbols. In contrast, computing with words, or CW for short, is a methodology in which the objects of computation are words and propositions drawn from a natural language, e.g., small, large, far, heavy, not very likely, the price of gas is low and declining, Berkeley is near San Francisco, it is very unlikely that there will be a significant increase in the price of oil in the near future, etc. Computing with words is inspired by the remarkable human capability to perform a wide variety of physical and mental tasks without any measurements and any computations. Familiar examples of such tasks are parking a car, driving in heavy traffic, playing golf, riding a bicycle, understanding speech and summarizing a story. Underlying this remarkable capability is the brain's crucial ability to manipulate perceptions-perceptions of distance, size, weight, color, speed, time, direction, force, number, truth, likelihood and other characteristics of physical and mental objects. Manipulation of perceptions plays a key role in human recognition, decision and execution processes. As a methodology, computing with words provides a foundation for a computational theory of perceptions-a theory which may have an important bearing on how humans make-and machines might make-perception-based rational decisions in an environment of imprecision, uncertainty and partial truth. A basic difference between perceptions and measurements is that, in general, measurements are crisp whereas perceptions are fuzzy. One of the fundamental aims of science has been and continues to be that of progressing from perceptions to measurements. Pursuit of this aim has led to brilliant successes. We have sent men to the moon; we can build computers that are capable of performing billions of computations per second; we have constructed telescopes that can explore the far reaches of the universe; and we can date the age of rocks that are millions of years old. But alongside the brilliant successes stand conspicuous underachievements and outright failures. We cannot build robots which can move with the agility of animals or humans; we cannot automate driving in heavy traffic; we cannot translate from one language to another at the level of a human interpreter; we cannot create programs which can summarize non-trivial stories; our ability to model the behavior of economic systems leaves much to be desired; and we cannot build machines that can compete with children in the performance of a wide variety of physical and cognitive tasks. It may be argued that underlying the underachivements and failures is the unavailability of a methodology for reasoning and computing with perceptions rather than measurements. An outline of such a methodology-referred to as a computational theory of perceptions-is presented in this paper. The computational theory of perceptions, or CTP for short, is based on the methodology of computing with words (CW). In CTP, words play the role of labels of perceptions and, more generally, perceptions are expressed as propositions in a natural language. CW-based techniques are employed to translate propositions expressed in a natural language into what is called the Generalized Constraint Language (GCL). In this language, the meaning of a proposition is expressed as a generalized constraint, X isr R, where X is the constrained variable, R is the constraining relation and isr is a variable copula in which r is a variable whose value defines the way in which R constrains X. Among the basic types of constraints are: possibilistic, veristic, probabilistic, random set, Pawlak singing then the emphasis is put on the action aspect, while if we want to say that the singing is loud then the emphasis is on the sound, which is treated as a thing since one hears it. The crucial point is that one seems to be forced to make such a distinction, as assists the determination of structure, but the origin of this distinction is probably related to the different ways actions and objects are represented

  5. Transporting Handicapped Students.

    ERIC Educational Resources Information Center

    Turner, Dayton Ray

    The book presents guidelines for adaptive transportation measures for handicapped students. Part 1 considers the transportation cycle as a means to evaluate individual student competencies at all logical points during the transportation experience. The transportation cycle is reviewed from deciding to transport the student to gaining access to…

  6. Temperature-Dependent Polarization in Field-Effect Transport and Photovoltaic Measurements of Methylammonium Lead Iodide.

    PubMed

    Labram, John G; Fabini, Douglas H; Perry, Erin E; Lehner, Anna J; Wang, Hengbin; Glaudell, Anne M; Wu, Guang; Evans, Hayden; Buck, David; Cotta, Robert; Echegoyen, Luis; Wudl, Fred; Seshadri, Ram; Chabinyc, Michael L

    2015-09-17

    While recent improvements in the reported peak power conversion efficiency (PCE) of hybrid organic-inorganic perovskite solar cells have been truly astonishing, there are many fundamental questions about the electronic behavior of these materials. Here we have studied a set of electronic devices employing methylammonium lead iodide ((MA)PbI3) as the active material and conducted a series of temperature-dependent measurements. Field-effect transistor, capacitor, and photovoltaic cell measurements all reveal behavior consistent with substantial and strongly temperature-dependent polarization susceptibility in (MA)PbI3 at temporal and spatial scales that significantly impact functional behavior. The relative PCE of (MA)PbI3 photovoltaic cells is observed to reduce drastically with decreasing temperature, suggesting that such polarization effects could be a prerequisite for high-performance device operation. PMID:26722725

  7. Radicals and Reservoirs in the GMI Chemistry and Transport Model: Comparison to Measurements

    NASA Technical Reports Server (NTRS)

    Douglas, Anne R.; Stolarski, Richard S.; Strahan, Susan E.; Connell, Peter S.

    2004-01-01

    The most important use of atmospheric chemistry and transport models is to predict the future composition of the atmosphere. The amounts of gases like chlorofluorcarbons, methyl bromide, nitrous oxide and methane are changing and the stratospheric ozone layer will change because these gases are changing. Methyl bromide, nitrous oxide and methane all have natural sources, and also change because of human activity. Chlorofluorcarbons are man-made gases; these are known to decrease stratospheric ozone and future production is banned. They are long-lived gases, and many decades will pass before they are insignificant in the atmosphere. The models are used to predict changes in ozone and other gases; this is a straightforward application. The models must be also tested using observations for the present day atmosphere. This is a challenging task, because the model contains more than 50 species and more than 150 chemical reactions. Data from satellites, ground stations, aircraft and balloons are used to evaluate the model. Different models that are used in international assessments produce different results; in the most recent assessment some predict that ozone will return to 1980 levels by 2025 and others predict that this will not happen until 2050. Since all the parts of the models are conceptually the same, there must be differences in implementation that produce these differences, This work takes a single model, two different sets of winds and temperatures, and repeats the same prediction for the future. Here we compare the results for these two simulations with many observations. The purpose is to identify differences in the model results for the present atmosphere that will lead to different predictions. This sort of controlled comparison will reduce uncertainty in the predictions for stratospheric ozone.

  8. Hydrogen transport diagnostics by atomic and molecular emission line profiles simultaneously measured for large helical device

    SciTech Connect

    Fujii, K.; Shikama, T.; Hasuo, M.; Goto, M.; Morita, S.

    2013-01-15

    We observe the Balmer-{alpha}, -{beta}, and -{gamma} lines of hydrogen atoms and Q branches of the Fulcher-{alpha} band of hydrogen molecules simultaneously with their polarization resolved for large helical device. From the fit including the line splits and the polarization dependences by the Zeeman effect, the emission locations, intensities, and the temperatures of the atoms and molecules are determined. The emission locations of the hydrogen atoms are determined outside but close to the last closed flux surface (LCFS). The results are consistent with a previous work (Phys. Plasmas 12, 042501 (2005)). On the other hand, the emission locations of the molecules are determined to be in the divertor legs, which is farer from those of the atoms. The kinetic energy of the atoms is 1 {approx} 20 eV, while the rotational temperature of molecules is {approx}0.04 eV. Additionally, substantial wings, which originate from high velocity atoms and are not reproduced by the conventional spectral analysis, are observed in the Balmer line profiles. We develop a one-dimensional model to simulate the transport of the atoms and molecules. The model reproduces the differences of the emission locations of the atoms and molecules when their initial temperatures are assumed to be 3 eV and 0.04 eV, respectively. From the model, the wings of the Balmer-{alpha} line is attributed to the high velocity atoms exist deep inside the LCFS, which are generated by the charge exchange collisions with hot protons there.

  9. Moissanite-anvil cells for the electrical transport measurements at low temperatures

    NASA Astrophysics Data System (ADS)

    Yomo, Shusuke; Tozer, Stanley W.

    2010-03-01

    We have successfully measured the Hall effect of a single crystal of a high temperature superconductor La2-xSrxCuO4 in moissanite-anvil high pressure cells. A pressure cell with new Zylon-gasket and wiring arrangement survived under pressure up to at least 5 GPa. Pressure which was clamped at room temperature increased with lowering the temperature down to below 60 K by a factor of 1.3-1.4.

  10. Measuring mRNA copy-number in individual Escherichia coli cells using single-molecule fluorescent in situ hybridization (smFISH)

    PubMed Central

    Skinner, Samuel O.; Sepúlveda, Leonardo A.; Xu, Heng; Golding, Ido

    2014-01-01

    We present a method for measuring the absolute number of mRNA molecules from a gene of interest in individual, chemically fixed Escherichia coli cells. A set of fluorescently-labeled oligonucleotide probes are hybridized to the target mRNA, so that each mRNA molecule is decorated by a known number of fluorescent dyes. Cells are then imaged using fluorescence microscopy. The number of target mRNA is estimated from the total intensity of fluorescent foci in the cell, rather than from counting discrete “spots” as in other currently available protocols. Image analysis is performed using an automated algorithm. The measured mRNA copy-number distribution obtained from many individual cells can be used to extract the parameters of stochastic gene activity, namely the frequency and size of transcription bursts from the gene of interest. The experimental procedure takes 2 days, with another 2-3 days typically required for image and data analysis. PMID:23680982

  11. Coherent infrared lidar mission and technology needs for measurements of transport and concentration of tropospheric trace species

    NASA Technical Reports Server (NTRS)

    Hess, R. V.; Brockman, P.; Bair, C. H.; Staton, L. D.; Lytle, C. D.; Laughman, L. M.; Kaplan, M. L.

    1983-01-01

    The science justification and the feasibility of aircraft-based CO2 Doppler lidar measurements of transport between the free troposphere and the stratosphere (or planetary boundary layer) are discussed for a wide range of seasonal and geographic conditions. Ground-based coherent CO2 lidar aerosol scattering experiments using a stable ring resonator (about 50 mJ/pulse) CO2 laser with external injection locking are reported. Comparative studies of injection-locked CO2 laser unstable resonators and master oscillator power amplifiers are reported for future CO2 lidar missions with respect to requirements of pulse energy, duration/shape, frequency chirp, efficiency for heterodyne detection, and combined Doppler lidar and Differential Absorption Lidar missions.

  12. Temperature and force dependence of electron transport via the copper protein azurin: conductive probe atomic force microscopy measurements

    E-print Network

    Li, Wenjie; Amdursky, Nadav; Cohen, Sidney R; Pecht, Israel; Sheves, Mordechai; Cahen, David

    2012-01-01

    We report conducting probe atomic force microscopy (CP-AFM) measurements of electron transport (ETp), as a function of temperature and force, through monolayers of holo-azurin (holo-Az) and Cu-depleted Az (apo-Az) that retain only their tightly bound water, immobilized on gold surfaces. The changes in CP-AFM current-voltage (I-V) curves for holo-Az and apo-Az, measured between 250 - 370K, are strikingly different. While ETp across holo-Az at low force (6 nN) is temperature-independent over the whole examined range, ETp across apo-Az is thermally activated, with calculated activation energy of 600\\pm100 meV. These results confirm our results of macroscopic contact area ETp measurements via holo- and apo-Az, as a function of temperature, where the crucial role of the Cu redox centre has been observed. While increasing the applied tip force from 6 to 12 nN did not significantly change the temperature dependence of ETp via apo-Az, ETp via holo-Az changed qualitatively, namely from temperature-independent at 6 nN ...

  13. Comparing three vegetation monoterpene emission models to measured gas concentrations with a model of meteorology, air chemistry and chemical transport

    NASA Astrophysics Data System (ADS)

    Smolander, S.; He, Q.; Mogensen, D.; Zhou, L.; Bäck, J.; Ruuskanen, T.; Noe, S.; Guenther, A.; Aaltonen, H.; Kulmala, M.; Boy, M.

    2013-11-01

    Biogenic volatile organic compounds (BVOCs) are essential in atmospheric chemistry because of their chemical reactions that produce and destroy tropospheric ozone, their effects on aerosol formation and growth, and their potential influence on global warming. As one of the important BVOC groups, monoterpenes have been a focus of scientific attention in atmospheric research. Detailed regional measurements and model estimates are needed to study emission potential and the monoterpene budget on a global scale. Since the use of empirical measurements for upscaling is limited by many physical and biological factors such as genetic variation, temperature and light, water availability, seasonal changes, and environmental stresses, comprehensive inventories over larger areas are difficult to obtain. We applied the boundary layer-chemistry-transport model SOSA to investigate Scots pine (Pinus sylvestris) monoterpene emissions in a boreal coniferous forest at the SMEAR II site, Southern Finland. SOSA was applied to simulate monoterpene emissions with three different emission modules: the semi-empirical G95, MEGAN 2.04 with improved descriptions of temperature and light responses and including also carbonyl emissions, and a process-based model SIM-BIM. For the first time, the emission models included seasonal and diurnal variations in both quantity and chemical species of emitted monoterpenes, based on parameterizations obtained from field measurements. Results indicate that modelling and observations agreed reasonably well, and that the model can be used for investigating regional air chemistry questions related to monoterpenes. The predominant modelled monoterpene concentrations, ?-pinene and ?3-carene, are consistent with observations.

  14. Measurements of Saharan Dust from the Fennec Aircraft Campaign: Giant Particles, Optical Properties and Effects of Transport

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; Rosenberg, P.; Sodemann, H.; Highwood, E.; McQuaid, J. B.; Marsham, J. H.; Washington, R.

    2014-12-01

    During June 2011 and 2012 the Fennec project took place in the Western Sahara desert. Ground based and airborne measurements were taken in remote desert regions of Mali, Mauritania and Algeria. This presentation will show new in-situ aircraft measurements of Saharan dust from the 2011 flights, with size distributions extending to 300 ?m, representing measurements extending further into the coarse mode than previously published for airborne Saharan dust. A significant coarse mode was present in the size distribution measurements with effective diameter from 2.3 to 19.4 ?m and coarse mode volume median diameter from 5.8 to 45.3 ?m. The mean size distribution had a larger relative proportion of coarse mode particles than previous aircraft measurements with significant contribution from the 'giant mode' - particles larger than 38 microns.Properties of dust size distribution and optical properties will be presented in relation to dust age since uplift, dust event type and altitude. Vertical distributions of dust over desert (for both fresh and aged dust events) and the Eastern Atlantic Ocean from 42 aircraft profiles will be presented, demonstrating how size distributions and optical properties change during the early stages of the dust lifecycle. Size distributions show a loss of 60 to 90% of particles larger than 30 microns 12 h after uplift. Single scattering albedo increases from 0.92 to 0.94 to 0.95 between fresh, aged, and Eastern Atlantic dust profiles. Finally the impact of transport and changing optical properties on the radiative effect of dust will be examined.

  15. Rocket-Model Measurements of Zero-Lift Damping in Roll of the Bell MX-776 Missile at Mach Numbers from 0.6 to 1.56

    NASA Technical Reports Server (NTRS)

    Bland, William N., Jr.; Purser, Paul E.

    1953-01-01

    The zero-lift damping in roll of the Bell MX-776 missile has been measured by a sting-mounted rocket-model technique at Mach numbers from 0.6 to 1.56. The damping-in-roll data, in general, show no unusual variation with Mach number. Aileron rolling-moment effectiveness derived from these data and previously obtained rolling-effectiveness data appear reasonable,

  16. Measurements of water uptake of maize roots: insights for traits that influence water transport from the soil

    NASA Astrophysics Data System (ADS)

    Ahmed, Mutez A.; Zarebanadkouki, Mohsen; Kroener, Eva; Carminati, Andrea

    2015-04-01

    Water availability is a primary constraint to the global crop production. Although maize (Zea mays L.) is one of the most important crops worldwide, there is limited information on the function of different root segments and types in extracting water from soils. Aim of this study was to investigate the location of water uptake in maize roots. We used neutron radiography to: 1) image the spatial distribution of maize roots in soil and 2) trace the transport of injected deuterated water (D2O) in soil and roots. Maize plants were grown in aluminum containers (40×38×1 cm) filled with sandy soil. The soil was partitioned into different compartments using 1-cm-thick layers of coarse sand. When the plants were two weeks-old we injected D2O into selected soil compartments. The experiments were performed during the day (transpiring plants) and night (non transpiring plants). The transport of D2O into roots was simulated using a convection-diffusion numerical model of D2O transport into roots. By fitting the observed D2O transport we quantified the diffusion coefficient and the water uptake of the different root segments. The maize root architecture consisted of a primary root, 4-5 seminal roots and many lateral roots connected to the primary and seminal roots. Laterals emerged from the proximal 15 cm of the primary and seminal roots. Both during day and night measurements, D2O entered more quickly into lateral roots than into primary and seminal roots. The quick transport of D2O into laterals was caused by the small radius of lateral roots. The diffusion coefficient of lateral roots (4.68×10-7cm2s-1)was similar to that of the distal segments of seminal roots (4.72×10-7cm2s-1) and higher than of the proximal segments (1.42×10-7cm2s-1). Water uptake of lateral roots (1.64×10-5cms-1)was much higher than that of the distal segments of seminal roots (1.18×10-12cms-1). Water uptake of the proximal seminal segments was negligible. We conclude that the function of lateral roots is to absorb water from the soil, while the function of the primary and seminal roots is to axially transport water to the shoot. Breeding for lateral roots with high radial conductivity and seminal roots with large xylem vessels diameter would be beneficial in agroecosystems where water is available. In contrast, in arid and semi-arid areas seminal roots with a smaller xylem vessel diameter combined with deep branching of laterals would reduce transpiration rate and at the same time allow the uptake of water stored in the subsoil (Richards and Passioura 1989). Reference Richards RA, Passioura JB. (1989) A breeding program to reduce the diameter of the major xylem vessel in the seminal roots of wheat and its effect on grain yield in rain-fed environments. Australian Journal of Agricultural Research 40, 943-950.

  17. Separation of Rashba and Dresselhaus spin-orbit interactions using crystal direction dependent transport measurements

    SciTech Connect

    Ho Park, Youn; Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 ; Kim, Hyung-jun; Chang, Joonyeon; Hee Han, Suk; Eom, Jonghwa; Choi, Heon-Jin; Cheol Koo, Hyun

    2013-12-16

    The Rashba spin-orbit interaction effective field is always in the plane of the two-dimensional electron gas and perpendicular to the carrier wavevector but the direction of the Dresselhaus field depends on the crystal orientation. These two spin-orbit interaction parameters can be determined separately by measuring and analyzing the Shubnikov-de Haas oscillations for various crystal directions. In the InAs quantum well system investigated, the Dresselhaus term is just 5% of the Rashba term. The gate dependence of the oscillation patterns clearly shows that only the Rashba term is modulated by an external electric field.

  18. Measurements of Local Heat Transfer and Pressure on Six 2-Inch-Diameter Blunt Bodies at a Mach Number of 4.95 and at Reynolds Numbers Per Foot up to 81 x 10(exp 6)

    NASA Technical Reports Server (NTRS)

    Cooper, Morton; Mayo, Edward E.

    1959-01-01

    Measurements of the local heat transfer and pressure distribution have been made on six 2-inch-diameter, blunt, axially symmetric bodies in the Langley gas dynamics laboratory at a Mach number of 4.95 and at Reynolds numbers per foot up to 81 x 10(exp 6). During the investigation laminar flow was observed over a hemispherical-nosed body having a surface finish from 10 to 20 microinches at the highest test Reynolds number per foot (for this configuration) of 77.4 x 10(exp 6). Though it was repeatedly possible to measure completely laminar flow at this Reynolds number for the hemisphere, it was not possible to observe completely laminar flow on the flat-nosed body for similar conditions. The significance of this phenomenon is obscured by the observation that the effects of particle impacts on the surface in causing roughness were more pronounced on the flat-nosed body. For engineering purposes, a method developed by M. Richard Dennison while employed by Lockheed Aircraft Corporation appears to be a reasonable procedure for estimating turbulent heat transfer provided transition occurs at a forward location on the body. For rearward-transition locations, the method is much poorer for the hemispherical nose than for the flat nose. The pressures measured on the hemisphere agreed very well with those of the modified Newtonian theory, whereas the pressures on all other bodies, except on the flat-nosed body, were bracketed by modified Newtonian theory both with and without centrifugal forces. For the hemisphere, the stagnation-point velocity gradient agreed very well with Newtonian theory. The stagnation-point velocity gradient for the flat- nosed model was 0.31 of the value for the hemispherical-nosed model. If a Newtonian type of flow is assumed, the ratio 0.31 will be independent of Much number and real-gas effects.

  19. 49 CFR 821.3 - Description of docket numbering system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) NATIONAL TRANSPORTATION SAFETY BOARD RULES OF PRACTICE IN AIR SAFETY PROCEEDINGS General Provisions § 821.3 Description of docket numbering system....

  20. Understanding electric field-enhanced transport for the measurement of nanoparticles and their assembly on surfaces

    NASA Astrophysics Data System (ADS)

    Tsai, De-Hao

    The goal of this dissertation is to understand the synthesis, characterization, and integration of nanoparticles and nanoparticle-based devices by electric field-enhanced transport of nanoparticles. Chapter I describes the factors used for determining particle trajectories and found that electric fields provide the directional electrostatic force to overcome other non-directional influences on particle trajectories. This idea is widely applied in the nanoparticle classification, characterization, and assembly onto substrate surfaces as investigated in the following chapters. Chapter 2 presents a new assembly method to position metal nanoparticles delivered from the gas phase onto surfaces using the electrostatic force generated by biased p-n junction patterned substrates. Aligned deposition patterns of metal nanoparticles were observed, and the patterning selectivity quantified. A simple model accounting for the generated electric field, and the electrostatic, van der Waals, and image forces was used to explain the observed results. Chapter 2.2 describes a data set for particle size resolved deposition, from which a Brownian dynamics model for the process can be evaluated. Brownian motion and fluid convection of nanoparticles, as well as the interactions between the charged nanoparticles and the patterned substrate, including electrostatic force, image force and van der Waals force, are accounted for in the simulation. Using both experiment and simulation the effects of the particle size, electric field intensity, and the convective flow on coverage selectivity have been investigated. Coverage selectivity is most sensitive to electric field, which is controlled by the applied reverse bias voltage across the p-n junction. A non-dimensional analysis of the competition between the electrostatic and diffusion force is found to provide a means to collapse a wide range of process operating conditions and an effective indicator or process performance. Directed assembly of size-selected nanoparticles has been applied in the study of nanoparticle enhanced fluorescence (NEF) bio-sensing devices. Chapter 3 presents results of a systematic examination of funct onalized gold nanoparticles by electrospray-differential mobility analysis (ES-DMA). Formation of selfassembled monolayers (SAMs) of alkylthiol molecules and singly stranded DNA (ssDNA) on the Au-NP surface was detected from a change in particle mobility, which could be modeled to extract the surface packing density. A gas-phase temperature-programmed desorption (TPD) kinetic study of SAMs on the Au-NP found the data to be consistent with a second order Arrhenius based rate law, yielding an Arrhenius-factor of 1x1011s -1 and an activation energy ˜105 kJ/mol. This study suggests that the ES-DMA can be added to the tool set of characterization methods being employed and developed to study the structure and properties of coated nanoparticles. Chapter 3.2 demonstrates this ES-DMA as a new method to investigate colloidal aggregation and the parameters that govern it. Nanoparticle suspensions were characterized by sampling a Au nanoparticle (Au-NP) colloidal solution via electrospray (ES), followed by differential ion-mobility analysis (DMA) to determine the mobility distribution, and thus the aggregate distribution. By sampling at various times, the degree of flocculation and the flocculation rate are determined and found to be inversely proportional to the ionic strength and proportional to the residence time. A stability ratio at different ionic strengths, the critical concentration, and surface potential or surface charge density of Au-NPs are obtained from these data. This method should be a generically useful tool to probe the early stages of colloidal aggregation. Study of ES-DMA is extended to include the characterizations of a variety of materials. Biologically interested materials such as viruses and antibodies could also be characterized. These results show ES-DMA provides a general way to characterize the colloidal materials as well as aerosolized particles.

  1. Measurements of Electron Thermal Transport due to Electron Temperature Gradient Modes in a Basic Experiment

    SciTech Connect

    Sokolov, V.; Sen, A. K.

    2011-10-07

    Production and identification of electron temperature gradient modes have already been reported [X. Wei, V. Sokolov, and A. K. Sen, Phys. Plasmas 17, 042108 (2010)]. Now a measurement of electron thermal conductivity via a unique high frequency triple probe yielded a value of {chi}{sub perpendiculare} ranging between 2 and 10 m{sup 2}/s, which is of the order of a several gyrobohm diffusion coefficient. This experimental result appears to agree with a value of nonlocal thermal conductivity obtained from a rough theoretical estimation and not inconsistent with gyrokinetic simulation results for tokamaks. The first experimental scaling of the thermal conductivity versus the amplitude of the electron temperature gradient fluctuation is also obtained. It is approximately linear, indicating a strong turbulence signature.

  2. Plasmon transport in graphene investigated by time-resolved electrical measurements

    PubMed Central

    Kumada, N.; Tanabe, S.; Hibino, H.; Kamata, H.; Hashisaka, M.; Muraki, K.; Fujisawa, T.

    2013-01-01

    Plasmons, which are collective charge oscillations, could provide a means of confining electromagnetic field to nanoscale structures. Recently, plasmonics using graphene have attracted interest, particularly because of the tunable plasmon dispersion, which will be useful for tunable frequency in cavity applications. However, the carrier density dependence of the dispersion is weak (proportional to n1/4) and it is difficult to tune the frequency over orders of magnitude. Here, by exploiting electronic excitation and detection, we carry out time-resolved measurements of a charge pulse travelling in a plasmon mode in graphene corresponding to the gigahertz range. We demonstrate that the plasmon velocity can be changed over two orders of magnitude by applying a magnetic field B and by screening the plasmon electric field with a gate metal; at high B, edge magnetoplasmons, which are plasmons localized at the sample edge, are formed and their velocity depends on B, n and the gate screening effect. PMID:23322051

  3. Sub-10?nm nano-gap device for single-cluster transport measurements

    SciTech Connect

    Rousseau, J. Morel, R.; Vila, L.; Brenac, A.; Marty, A.; Notin, L.; Beigné, C.

    2014-02-17

    We present a versatile procedure for the fabrication of single electron transistor (SET) devices with nanometer-sized clusters and embedded back gate electrode. The process uses sputtering gas-aggregation for the growth of clusters and e-beam lithography with double angle shadow-edge deposition to obtain electrodes separated by nano-gaps with width below 10?nm. The nano-gap width is easily controlled only by geometrical factors such as deposited thin film thickness and evaporation angles. The usefulness of this technique is demonstrated by measuring the SET behavior of a device with a 4?nm cobalt cluster embedded in alumina, where the Coulomb blockade and incremental cluster charging can be readily identified without resorting to the differential conductivity.

  4. Comparing three vegetation monoterpene emission models to measured gas concentrations with a model of meteorology, air chemistry and chemical transport

    NASA Astrophysics Data System (ADS)

    Smolander, S.; He, Q.; Mogensen, D.; Zhou, L.; Bäck, J.; Ruuskanen, T.; Noe, S.; Guenther, A.; Aaltonen, H.; Kulmala, M.; Boy, M.

    2014-10-01

    Biogenic volatile organic compounds (BVOCs) are essential in atmospheric chemistry because of their chemical reactions that produce and destroy tropospheric ozone, their effects on aerosol formation and growth, and their potential influence on global warming. As one of the important BVOC groups, monoterpenes have been a focus of scientific attention in atmospheric research. Detailed regional measurements and model estimates are needed to study emission potential and the monoterpene budget on a global scale. Since the use of empirical measurements for upscaling is limited by many physical and biological factors, such as genetic variation, temperature and light, water availability, seasonal changes, and environmental stresses, comprehensive inventories over larger areas are difficult to obtain. We applied the boundary-layer-chemistry-transport model SOSA (model to Simulate the concentrations of Organic vapours and Sulphuric Acid) to investigate Scots pine (Pinus sylvestris) monoterpene emissions in a boreal coniferous forest at the SMEAR (Station for Measuring forest Ecosystem-Atmosphere Relations) II site, southern Finland. SOSA was applied to simulate monoterpene emissions with three different emission modules: the semiempirical G95, MEGAN (Model of Emissions of Gases and Aerosols from Nature) 2.04 with improved descriptions of temperature and light responses and including also carbonyl emissions, and a process-based model SIM-BIM (Seasonal Isoprenoid synthase Model - Biochemical Isoprenoid biosynthesis Model). For the first time, the emission models included seasonal and diurnal variations in both quantity and chemical species of emitted monoterpenes, based on parameterizations obtained from field measurements. Results indicate that modelling and observations agreed reasonably well and that the model can be used for investigating regional air chemistry questions related to monoterpenes. The predominant modelled monoterpene concentrations, ?-pinene and ?3-carene, are consistent with observations.

  5. A Comparison of Rome Observatory Sunspot Area and Sunspot Number Determinations With International Measures, 1958-1998

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2005-01-01

    Two changes in recording the sunspot record have occurred in recent years. First, in 1976, the longer-than-100-yr daily photographic record of the Royal Greenwich Observatory (RGO), used for determination of numbers and positions of sunspot groups and sunspot areas ended, and second, at the end of 1980, after more than 130 years, Zurich s Swiss Federal Observatory stopped providing daily sunspot numbers. To extend the sunspot record beyond 1976, use of United States Air Force/National Oceanic and Atmospheric Administration (USAF/NOAA) sunspot drawing observations from the Solar Optical Observing Network began in 1977, and the combined record of sunspot activity from RGO/USAF/NOAA was made accessible at http://science.nasa.gov/ssl/PAD/SOLAR/greenwch.htm. Also, in 1981, the task of providing daily sunspot numbers was taken up by the Royal Observatory of Belgium s Solar Influences and Data analysis Center, and the combined Zurich/International sunspot number database was made available at http://sidc.oma.be/index.php3. In this study, Rome Observatory 1958-1998 photographic records of sunspot areas, numbers of groups, and derived sunspot numbers are compared against same-day international values to determine relative behaviors and to evaluate whether any potential changes might have been introduced in the overall sunspot record, due to the aforementioned changes.

  6. Flight-measured pressure characteristics of aft-facing steps in high Reynolds number flow at Mach numbers of 2.20, 2.50, and 2.80 and comparison with other data

    NASA Technical Reports Server (NTRS)

    Powers, S. G.

    1978-01-01

    The YF-12 airplane was studied to determine the pressure characteristics associated with an aft-facing step in high Reynolds number flow for nominal Mach numbers of 2.20, 2.50, and 2.80. Base pressure coefficients were obtained for three step heights. The surface static pressures ahead of and behind the step were measured for the no-step condition and for each of the step heights. A boundary layer rake was used to determine the local boundary layer conditions. The Reynolds number based on the length of flow ahead of the step was approximately 10 to the 8th power and the ratios of momentum thickness to step height ranged from 0.2 to 1.0. Base pressure coefficients were compared with other available data at similar Mach numbers and at ratios of momentum thickness to step height near 1.0. In addition, the data were compared with base pressure coefficients calculated by a semiempirical prediction method. The base pressure ratios are shown to be a function of Reynolds number based on momentum thickness. Profiles of the surface pressures ahead of and behind the step and the local boundary layer conditions are also presented.

  7. On the Use of Ocean Color Remote Sensing to Measure the Transport of Dissolved Organic Carbon by the Mississippi River Plume

    NASA Technical Reports Server (NTRS)

    DelCastillo, Carlos E.; Miller, Richard L.

    2007-01-01

    We investigated the use of ocean color remote sensing to measure transport of dissolved organic carbon (DOC) by the Mississippi River to the Gulf of Mexico. From 2000 to 2005 we recorded surface measurements of DOC, colored dissolved organic matter (CDOM), salinity, and water-leaving radiances during five cruises to the Mississippi River Plume. These measurements were used to develop empirical relationships to derive CDOM, DOC, and salinity from monthly composites of SeaWiFS imagery collected from 1998 through 2005. We used river flow data and a two-end-member mixing model to derive DOC concentrations in the river end-member, river flow, and DOC transport using remote sensing data. We compared our remote sensing estimates of river flow and DOC transport with data collected by the United States Geological Survey (USGS) from 1998 through 2005. Our remote sensing estimates of river flow and DOC transport correlated well (r2 0.70) with the USGS data. Our remote sensing estimates and USGS field data showed low variability in DOC concentrations in the river end-member (7-11%), and high seasonal variability in river flow (50%). Therefore, changes in river flow control the variability in DOC transport, indicating that the remote sensing estimate of river flow is the most critical element of our DOC transport measurement. We concluded that it is possible to use this method to estimate DOC transport by other large rivers if there are data on the relationship between CDOM, DOC, and salinity in the river plume.

  8. Measurement of Electron Transportation Properties in Liquid Argon for Large Liquid Argon Time Projection Chambers

    NASA Astrophysics Data System (ADS)

    Joshi, Jyoti; Li, Yichen; Qian, Xin; Thorn, Craig

    2015-04-01

    Liquid Argon (LAr) Time Projection Chambers (TPCs) provide a powerful, robust and elegant solution for the detection of neutrinos and other weakly interacting particles above a few tens of MeV. An energetic charged particle transiting the liquid produces ionization electrons that are drifted with constant velocity along a uniform electric field. By detecting the location and timing of the arrival of these electrons on a readout plane, LArTPCs provide 3D imaging of interaction events with excellent spatial resolution. During the drift to the readout plane, the ionization electrons diffuse. The resulting increase in the size of the charge distribution is one fundamental limitation to reach high spatial resolution at long drift distance. In addition, accurate modeling of the LArTPCs performance requires an accurate knowledge of the diffusion. In this talk, we report the measurement of longitudinal electron diffusion coefficients for a range of electric fields, which is directly applicable to existing LAr TPC experiments such as MicroBooNE. We also present the ongoing R&D to advance our knowledge of LAr properties at BNL, which are essential for the design and optimal operation of future large LArTPCs such as the proposed LBNF far detector.

  9. The impact of transportation control measures on emission reductions during the 2008 Olympic Games in Beijing, China

    NASA Astrophysics Data System (ADS)

    Zhou, Yu; Wu, Ye; Yang, Liu; Fu, Lixin; He, Kebin; Wang, Shuxiao; Hao, Jiming; Chen, Jinchuan; Li, Chunyan

    2010-01-01

    Traffic congestion and air pollution were two major challenges for the planners of the 2008 Olympic Games in Beijing. The Beijing municipal government implemented a package of temporary transportation control measures during the event. In this paper, we report the results of a recent research project that investigated the effects of these measures on urban motor vehicle emissions in Beijing. Bottom-up methodology has been used to develop grid-based emission inventories with micro-scale vehicle activities and speed-dependent emission factors. The urban traffic emissions of volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NO x) and particulate matter with an aerodynamic diameter of 10 ?m or less (PM 10) during the 2008 Olympics were reduced by 55.5%, 56.8%, 45.7% and 51.6%, respectively, as compared to the grid-based emission inventory before the Olympics. Emission intensity was derived from curbside air quality monitoring at the North 4th Ring Road site, located about 7 km from the National Stadium. Comparison between the emission intensity before and during the 2008 Olympics shows a reduction of 44.5% and 49.0% in daily CO and NO x emission from motor vehicles. The results suggest that reasonable traffic system improvement strategies along with vehicle technology improvements can contribute to controlling total motor vehicle emissions in Beijing after the Olympic Games.

  10. Transport analysis of measured neutron leakage spectra from spheres as tests of evaluated high energy cross sections

    NASA Technical Reports Server (NTRS)

    Bogart, D. D.; Shook, D. F.; Fieno, D.

    1973-01-01

    Integral tests of evaluated ENDF/B high-energy cross sections have been made by comparing measured and calculated neutron leakage flux spectra from spheres of various materials. An Am-Be (alpha,n) source was used to provide fast neutrons at the center of the test spheres of Be, CH2, Pb, Nb, Mo, Ta, and W. The absolute leakage flux spectra were measured in the energy range 0.5 to 12 MeV using a calibrated NE213 liquid scintillator neutron spectrometer. Absolute calculations of the spectra were made using version 3 ENDF/B cross sections and an S sub n discrete ordinates multigroup transport code. Generally excellent agreement was obtained for Be, CH2, Pb, and Mo, and good agreement was observed for Nb although discrepancies were observed for some energy ranges. Poor comparative results, obtained for Ta and W, are attributed to unsatisfactory nonelastic cross sections. The experimental sphere leakage flux spectra are tabulated and serve as possible benchmarks for these elements against which reevaluated cross sections may be tested.

  11. VOLUME 81, NUMBER 5 P H Y S I C A L R E V I E W L E T T E R S 3 AUGUST 1998 Enhanced Heat Transport in Turbulent Convection over a Rough Surface

    E-print Network

    Tong, Penger

    ]. Intermittent bursts of thermal plumes from the thermal boundary layers and the coherent large- scaleVOLUME 81, NUMBER 5 P H Y S I C A L R E V I E W L E T T E R S 3 AUGUST 1998 Enhanced Heat Transport in Turbulent Convection over a Rough Surface Y.-B. Du and P. Tong* Department of Physics, Oklahoma State

  12. Transport Measurements in the Mixed Ion-Electron Conductor Copper(x) Carbon-Disulfide

    NASA Astrophysics Data System (ADS)

    Kuo, Hung-Jen

    (sigma)(,i), (sigma)(,e), and the chemical diffusion coefficient, (')D, of highly-disordered Cu(,x)CS(,2) were investigated using a dc 4-lead technique employing Pt electrodes. The experiments were performed at various copper concentrations from x = 2.87 to 3.60 and various temperatures from 260 K to 350 K. The results were interpreted by Yokota's and ionic hopping diffusion theories. (sigma)(,i) and (sigma)(,e) are comparable at room temperature, 4.18 x 10('-3) (OMEGA)('-1)cm('-1) and 1.55 x 10('-3) (OMEGA)('-1)cm('-1) respectively at X = 3.60 and 300 K. Both (sigma)(,i) and (sigma)(,e) follow a simple Arrhenius form with activation energies (TURN)0.40 eV and (TURN)0.29 eV respectively. The exponential dependence of (sigma)(,i) on X is explained in terms of the activation entropy associated with the motion of ions. Electronic conduction is by hopping. Results show that it is reasonable to assume that all the copper ions are mobile. The mobility and the diffusivity of copper ions were found to be 0.71 x 10('-6) cm('2)V(' -1)sec('-1) and 1.83 x 10('-8) cm('2)/sec respectively at X = 3.6 and 300 K. The diffusivity is much less than the chemical diffusion coefficient evaluated from the diffusion time constant, (')D = 0.829 x 10('-5) cm('2)/sec at X = 3.60 and 300 K. This is because of a large enhancement factor W (TURN) 453, or a large (PAR-DIFF)m(,e)/(PAR-DIFF)N. The change in galvanic cell potential E with X, -(PAR-DIFF)E/(PAR -DIFF)X, calculated from the measurements of (sigma)(,i), (sigma)(,e), and (')D, is 14 Volt.

  13. Multi-Instrumental Measurement of Bedload Transport and Turbulent Resuspension over Lateral Sand Bars in the Lower Mississippi River

    NASA Astrophysics Data System (ADS)

    Ramirez, M. T.; Allison, M. A.; Meselhe, E. A.; Duncan, D. D.

    2010-12-01

    Two reaches of the lower Mississippi River at Myrtle Grove, LA (river kilometer 95-100 above Head of Passes) and Magnolia, LA (river kilometer 72-76) were examined during rising river discharge in April (23,800 cms) and May (19,300 cms) 2010 using a multi-instrumental approach to observe the dynamics of bedload transport and turbulent resuspension over lateral river sand bars. The key concept is to quantify and model to what extent (vertically and spatially) sediments sourced from the bar contribute to the suspended sand flux sourced from upriver: this issue is critical to determine sediment loads available for capture by planned river diversion structures. Following basemapping of bar morphology with multibeam bathymetry, longitudinal and cross-sectional surveys with ADCP and ABS were used to define the bottom stress field and suspended sediment load from backscatter. Suspended sediment concentrations and particle sizes (disaggregated and aggregate) were measured using isokinetic samplers, and wire-deployed (stationary and towed) LISST and optical sensors (transmissometer, OBS): bottom sands were also sampled by grab. Bedload sediment transport was quantified from repeated multibeam surveys of migrating sand dunes. Preliminary results suggest a depth-related bar effect: the shallower bar at Magnolia shows evidence of larger dunes than Myrtle Grove at a given flow. Discharge is also critical in setting dune size, which has a feedback (form-drag) on the magnitude and height above the bottom of resuspension. Daily surveys during the five-day rising discharge May study captured the threshold for bed sand becoming a significant contributor to the suspended sand flux, particularly at Magnolia.

  14. > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 1 The Assessment of the Measurement of the

    E-print Network

    > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) and the X notation refers to the vector cross-product. The basic idea investigated is to directly measure S r and use this sensory information for power engineering supervision and control. Manuscript

  15. Measuring Gravel Transport in an Active Natural System: An Analytical Framework

    NASA Astrophysics Data System (ADS)

    Sanfilippo, J. D.; Lancaster, S. T.

    2014-12-01

    In order to measure sediment flux in Porter Creek, a small tributary to the North Fork of the Siuslaw River near Florence Oregon, we have deployed ~600 pieces of tracer gravel embedded with passive integrated transponder (PIT) tags, 8 fixed antennas, and 9 logging pressure transducers spaced along 130 m of channel comprising 3 wood jams and substrates of sand, gravel, cobble, and bedrock. Tracer deployment is uniform along the instrumented reach, analogous to constant-source solute or dye injection, so that sediment flux [L3/T] for the ith grain size class is Qi = niVpiFi/fTi, where ni is count rate, [T-1], Vpi is particle volume, and Fi and fTi are fractional coverage of the ith size class of grains and tracers, respectively. Tracer concentrations, fTi, must be large enough for accurate estimation of ni = 1/TAi where TAi is the mean inter-arrival time of tracers at an antenna, during a period of nearly constant discharge. A square wave or constant sediment injection is undertaken by placing a concentration of tracers dispersed upstream of the study reach, such that it will add to the concentration within the study reach as gravels migrate downstream, replacing the gravels within the antenna network. Preliminary results show dispersion values ranging from ~7 m2/month for 8-16mm size fraction, to ~0.2 m2/month for 32-64mm size fraction, with travel distances of 60 meters for the 8-16mm, 16 meters for the 16-32mm, 8 meters for the 32-64mm, and 4 meters for the >64mm for 1 water year. Since there is a high level of variability in dispersion within the antennae array given the heterogeneity of substrates and wood placed within the system, it is likely that some tracers will need to be added within the regions between antennae after high water events. The tracer concentration within the regions occupied between antennae must remain at such a level as to provide viable statistical relationships between tracer and non-tracer gravels, and percent mobile versus percent stationary.

  16. Calibration of a transient transport model to tritium measurements in rivers and streams in the Western Lake Taupo catchment, New Zealand

    NASA Astrophysics Data System (ADS)

    Gusyev, M. A.; Toews, M.; Morgenstern, U.; Stewart, M.; Daughney, C.; Hadfield, J.

    2012-08-01

    Here we present a general approach of calibrating transient transport models to tritium concentrations in river waters developed for the MT3DMS/MODFLOW model of the Western Lake Taupo catchment, New Zealand. Tritium is a time-dependent tracer with radioactive half-life of 12.32 yr. In the transport model, the tritium input (measured in rain) passes through the groundwater system, and the modelled tritium concentrations are compared to the measured tritium concentrations in the river outlets for the Waihaha, Whanganui, Whareroa, Kuratau and Omori river catchments from 2000-2007. For the Kuratau River, tritium was also measured between 1960 and 1970, which allowed us to fine-tune the transport model. In order to incorporate all surface flows from rivers to small streams, an 80 m uniform grid cell size was selected in the steady-state MODFLOW model for the model area of 1072 km2. The groundwater flow model was first calibrated to groundwater levels and stream flow observations. Then, the transport model was calibrated to the measured tritium concentrations in the river waters. The MT3DMS model results show good agreement with the measured tritium values in all five river catchments. Finally, the calibrated MT3DMS model is applied to simulate groundwater ages that are used to construct groundwater age distributions for the river catchments.

  17. Contributions of regional transport and local sources to ozone exceedances in Houston and Dallas: Comparison of results from a photochemical grid model to aircraft and surface measurements

    NASA Astrophysics Data System (ADS)

    Kemball-Cook, Susan; Parrish, David; Ryerson, Thomas; Nopmongcol, Uarporn; Johnson, Jeremiah; Tai, Edward; Yarwood, Greg

    2009-04-01

    During the 2000 Texas Air Quality Study (TexAQS) and 2006 Texas Air Quality Study (TexAQS II) field experiments, aircraft measured ozone concentrations upwind, across, and downwind of the Houston and Dallas urban areas. Background ozone transported into Houston contributed, on average, approximately 50% and 66% of the total ozone on 8-h ozone exceedance days investigated by aircraft flights during TexAQS and TexAQS II, respectively. Analysis of a flight over Dallas on one exceedance day showed that transported ozone constituted 72% of the total ozone concentration. The aircraft measurements show that these two major metropolitan areas can be brought close to exceeding the 1997 8-h National Ambient Air Quality Standard for ozone of 0.08 ppm solely by the ozone contribution of regional transport before additional contribution from local sources. Large local contributions were also observed, particularly in Houston. Transport contributions to Dallas area ozone were quantified using the Comprehensive Air Quality Model with Extensions (CAMx) photochemical grid model and source apportionment methods. Model-predicted ozone concentrations were compared to ozone measurements from the aircraft and the surface monitoring network, and showed agreement on the importance of regional transport and local ozone formation. These results emphasize the benefits of regional control strategies, and suggest that local controls alone may not be sufficient to ensure attainment of the 8-h ozone standard in Houston and Dallas.

  18. Examining Item Functioning of Math Screening Measures for Grades 1-8 Students. Technical Report Number 08-04

    ERIC Educational Resources Information Center

    Liu, Kimy; Ketterlin-Geller, Leanne R.; Yovanoff, Paul; Tindal, Gerald

    2008-01-01

    BRT Math Screening Measures focus on students' mathematics performance in grade-level standards for students in grades 1-8. A total of 24 test forms are available with three test forms per grade corresponding to fall, winter, and spring testing periods. Each form contains computation problems and application problems. BRT Math Screening Measures

  19. Ground Measurements of Airplane Shock-Wave Noise at Mach Numbers to 2.0 and at Altitudes to 60,000 Feet

    NASA Technical Reports Server (NTRS)

    Lina, Lindsay J.; Maglieri, Domenic J.

    1960-01-01

    The intensity of shock-wave noise at the ground resulting from flights at Mach numbers to 2.0 and altitudes to 60,000 feet was measured. Meagurements near the ground track for flights of a supersonic fighter and one flight of a supersonic bomber are presented. Level cruising flight at an altitude of 60,000 feet and a Mach number of 2.0 produced sonic booms which were considered to be tolerable, and it is reasonable t o expect that cruising flight at higher altitudes will produce booms of tolerable intensity for airplanes of the size and weight of the test airplanes. The measured variation of sonic-boom intensity with altitude was in good agreement with the variation calculated by an equation given in NASA Technical Note D-48. The effect of Mach number on the ground overpressure is small between Mach numbers of 1.4 and 2.0, a result in agreement with the theory. No amplification of the shock-wave overpressures due to refraction effects was apparent near the cutoff Mach number. A method for estimating the effect of fligh-path angle on cutoff Mach number is shown. Experimental results indicate agreement with the method, since a climb maneuver produced booms of a much decreased intensity as compared with the intensity of those measured in level flight at about the same altitude and Mach number. Comparison of sound pressure levels for the fighter and bomber airp lanes indicated little effect of either airplane size or weight at an altitude of 40,000 feet.

  20. Measurements in Flight of the Pressure Distribution on the Right Wing of a Pursuit-Type Airplane at Several Values of Mach Number

    NASA Technical Reports Server (NTRS)

    Clousing, Lawrence A; Turner, William N; Rolls, L Stewart

    1946-01-01

    Pressure-distribution measurements were made on the right wing of a pursuit-type airplane at values of Mach number up to 0.80. The results showed that a considerable portion of the lift was carried by components of the airplane other than the wings, and that the proportion of lift carried by the wings may vary considerably with Mach number, thus changing the bending moment at the wing root whether or not there is a shift in the lateral position of the center of pressure. It was also shown that the center of pressure does not necessarily move outward at high Mach numbers, even though the wing-thickness ratio decreases toward the wing tip. The wing pitching-moment coefficient increased sharply in a negative direction at a Mach lift-curve slope increased with Mach number up to values of above the critical value. Pressures inside the wing were small and negative.

  1. Transportation and lairage environment effects on prevalence, numbers, and diversity of Escherichia coli O157:H7 on hides and carcasses of beef cattle at processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hide has been established as the main source of carcass contamination during processing, therefore, it is crucial to minimize the amount of Escherichia coli O157:H7 on cattle hides prior to slaughter. There are several potential sources of E. coli O157:H7 encountered in the transportation to and la...

  2. SMN1 and SMN2 copy numbers in cell lines derived from patients with spinal muscular atrophy as measured by array digital PCR

    PubMed Central

    Stabley, Deborah L; Harris, Ashlee W; Holbrook, Jennifer; Chubbs, Nicholas J; Lozo, Kevin W; Crawford, Thomas O; Swoboda, Kathryn J; Funanage, Vicky L; Wang, Wenlan; Mackenzie, William; Scavina, Mena; Sol-Church, Katia; Butchbach, Matthew E R

    2015-01-01

    Proximal spinal muscular atrophy (SMA) is an early-onset motor neuron disease characterized by loss of ?-motor neurons and associated muscle atrophy. SMA is caused by deletion or other disabling mutation of survival motor neuron 1 (SMN1). In the human genome, a large duplication of the SMN-containing region gives rise to a second copy of this gene (SMN2) that is distinguishable by a single nucleotide change in exon 7. Within the SMA population, there is substantial variation in SMN2 copy number; in general, those individuals with SMA who have a high SMN2 copy number have a milder disease. Because SMN2 functions as a disease modifier, its accurate copy number determination may have clinical relevance. In this study, we describe the development of an assay to assess SMN1 and SMN2 copy numbers in DNA samples using an array-based digital PCR (dPCR) system. This dPCR assay can accurately and reliably measure the number of SMN1 and SMN2 copies in DNA samples. In a cohort of SMA patient-derived cell lines, the assay confirmed a strong inverse correlation between SMN2 copy number and disease severity. Array dPCR is a practical technique to determine, accurately and reliably, SMN1 and SMN2 copy numbers from SMA samples. PMID:26247043

  3. Absolute measurement of the effective atomic number and the electron density by using dual-energy CT images

    NASA Astrophysics Data System (ADS)

    Kim, Dae-Hong; Lee, Won-Hyung; Jeon, Sung-Soo; Kim, Hee-Joung

    2012-12-01

    Material decomposition using dual-energy and material-selective techniques was performed using computed-tomography (CT)-generated reconstructed images. Previous work using the dual-energy method focused on extracting the effective atomic number and the electron density of materials to confirm the dosimetric accuracy in radiation therapy. Dual-energy methods mostly depend on the device generating the X-rays, such as a synchrotron, and on dose verification for radiation treatment planning. Information obtained from CT imaging is important both in diagnosis and in planning radiation therapy. In a clinical setting, CT images are usually displayed as Houndsfield units (HU), which are extracted from the attenuation coefficient of a material. The attenuation coefficient is calculated using the effective atomic number and the electron density of a material; thus, information expressed in HU can be converted into the effective atomic number and the electron density by using the dual-energy equation. This study was performed using realistic Xray spectra to differentiate between the contrast media and plaque in vascular images. Our results suggest that the effective atomic number and electron density are useful in distinguishing between two adjacent materials with similar HUs.

  4. Visual Contrast Detection Cannot be Predicted from Surrogate Measures of Retinal Ganglion Cell Number and Sampling Density in Healthy Young Adults.

    PubMed

    Denniss, Jonathan; Turpin, Andrew; McKendrick, Allison M

    2014-11-18

    Purpose: To establish whether a clinically-exploitable relationship exists between surrogate measures of retinal ganglion cell (RGC) number and functional sampling density and visual contrast sensitivity in healthy young eyes. Methods: Psychometric functions for contrast detection were measured at 9° eccentricity in superior and inferior visual field from 20 healthy adults (age 23-43, median 26 years). Functions were compared to corresponding localised regions of retinal nerve fibre layer (RNFL) thickness measured by optical coherence tomography, a surrogate of RGC number, and to grating resolution acuity, a psychophysical surrogate of RGC sampling density. Correlations between psychometric function parameters and RGC surrogates were measured by Spearman's rank correlation. Results: All measures exhibited a two- to four-fold variation in our sample. Despite this, correlations between measures were weak. Correlations between psychometric function parameters (threshold, spread) and RNFL thickness ranged in magnitude from 0.05 to 0.19 (p=0.43 to 0.85). Grating resolution was sampling-limited for 16 of 20 participants in superior visual field, and for 12 of 20 participants in inferior visual field. Correlations between psychometric function parameters and grating resolution acuities ranged in magnitude from 0.05 to 0.36 (p=0.12 to 0.85) when all data were considered, and from 0.06 to 0.36 (p=0.26 to 0.87) when only sampling-limited data were considered. Conclusions: Despite considerable variation in both psychometric functions for contrast detection and surrogate measures of RGC number and sampling density among healthy eyes, relationships between these measures are weak. These relationships are unlikely to be exploitable for improving clinical tests in healthy populations. PMID:25406282

  5. The Effects of Stratospheric Chemistry and Transport on the Isotopic Compositions of Long-Lived Gases Measured at Earth's Surface

    NASA Astrophysics Data System (ADS)

    Kanu, A. M.; Boering, K. A.

    2014-12-01

    The isotopic compositions of a number of long-lived gases in Earth's atmosphere, including those for carbon dioxide (?18O, ?17O, and ?14C), nitrous oxide (?15N, ?15N?, and ?18O), methane (?13C and ?D), and molecular hydrogen (?D) undergo large changes in the stratosphere. These changes arise from the often unique photochemical isotope fractionation occurring there as well as the long residence times and mean ages of stratospheric air with respect to exchange with the troposphere of up to 5 years. Stratospheric air then returns to the troposphere and, in each case, can affect the isotopic composition of these gases measured at Earth's surface. In this work, we estimate the effect of stratospheric isotope fractionation on free tropospheric isotope compositions of CO2, N2O, CH4, and H2 on an annual and global mean basis. To do so, we calculate net isotope fluxes between the stratosphere and troposphere empirically from the correlation of the measured isotope compositions of these species with measured N2O mixing ratios on whole air samples collected in the stratosphere from stratospheric aircraft and balloons coupled with independent information on the global, annually-averaged loss rate of N2O. In each case, the effect is large enough to include in global models. In addition, we present arguments and evidence that deconvolving the stratospheric influence on surface measurements from source (or other) signals on higher spatial and temporal scales than 'global' and 'annually-averaged' is also necessary when using surface measurements of isotopic compositions to constrain the magnitudes and geographic distributions of the sources of these gases to the atmosphere.

  6. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Lei Zhou

    2000-01-30

    This is the second quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between Oct 1, 2000 and December 31, 2000. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 2: Addition of a foam generation and breaker system), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (d) Research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (e) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (h) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members. The tasks Completed During This Quarter are Task 7 and Task 8.

  7. Measurements of thermal transport in low stress silicon nitride films W. Holmes, a) J. M. Gildemeister, and P. L. Richards b)

    E-print Network

    Richards, Paul L.

    --N! membranes are being used in a variety of devices at or below liquid helium tem­ peratures. These include 1998! We have measured the thermal conductance, G , of '1 mm thick low stress silicon nitride membranes of surface condition indicating that the thermal transport is determined by bulk scattering. For T,4 K

  8. IMPROVING CHEMICAL TRANSPORT MODEL PREDICTIONS OF ORGANIC AEROSOL: MEASUREMENT AND SIMULATION OF SEMIVOLATILE ORGANIC EMISSIONS FROM MOBILE AND NON-MOBILE SOURCES

    EPA Science Inventory

    Organic material contributes a significant fraction of PM2.5 mass across all regions of the United States, but state-of-the-art chemical transport models often substantially underpredict measured organic aerosol concentrations. Recent revisions to these models that...

  9. Note: Fiber optic transport probe for Hall measurements under light and magnetic field at low temperatures: Case study of a two dimensional electron gas

    NASA Astrophysics Data System (ADS)

    Bhadauria, P. P. S.; Gupta, Anurag; Kumar, Pramod; Dogra, Anjana; Budhani, R. C.

    2015-05-01

    A fiber optic based probe is designed and developed for electrical transport measurements in presence of quasi-monochromatic (360-800 nm) light, varying temperature (T = 1.8-300 K), and magnetic field (B = 0-7 T). The probe is tested for the resistivity and Hall measurements performed on a LaAlO3-SrTiO3 heterointerface system with a conducting two dimensional electron gas.

  10. Stable measures of number sense accuracy in math learning disability: Is it time to proceed from basic science to clinical application?

    PubMed

    Júlio-Costa, Annelise; Starling-Alves, Isabella; Lopes-Silva, Júlia Beatriz; Wood, Guilherme; Haase, Vitor Geraldi

    2015-12-01

    Math learning disability (MLD) or developmental dyscalculia is a highly prevalent and persistent difficulty in learning arithmetic that may be explained by different cognitive mechanisms. The accuracy of the number sense has been implicated by some evidence as a core deficit in MLD. However, research on this topic has been mainly conducted in demographically selected samples, using arbitrary cut-off scores to characterize MLD. The clinical relevance of the association between number sense and MLD remains to be investigated. In this study, we aimed at assessing the stability of a number sense accuracy measure (w) across five experimental sessions, in two clinically defined cases of MLD. Stable measures of number sense accuracy estimate are required to clinically characterize subtypes of MLD and to make theoretical inferences regarding the underlying cognitive mechanisms. G. A. was a 10-year-old boy with MLD in the context of dyslexia and phonological processing impairment and his performance remained steadily in the typical scores range. The performance of H. V., a 9-year-old girl with MLD associated with number sense inaccuracy, remained consistently impaired across measurements, with a nonsignificant tendency to worsen. Qualitatively, H. V.'s performance was also characterized by greater variability across sessions. Concomitant clinical observations suggested that H. V.'s difficulties could be aggravated by developing symptoms of mathematics anxiety. Results in these two cases are in line with the hypotheses that at least two reliable patterns of cognitive impairment may underlie math learning difficulties in MLD, one related to number sense inaccuracy and the other to phonological processing impairment. Additionally, it indicates the need for more translational research in order to examine the usefulness and validity of theoretical advances in numerical cognition to the clinical neuropsychological practice with MLD. PMID:26459122

  11. Estimates of Radioxenon Released from Southern Hemisphere Medical isotope Production Facilities Using Measured Air Concentrations and Atmospheric Transport Modeling

    SciTech Connect

    Eslinger, Paul W.; Friese, Judah I.; Lowrey, Justin D.; McIntyre, Justin I.; Miley, Harry S.; Schrom, Brian T.

    2014-09-01

    Abstract The International Monitoring System (IMS) of the Comprehensive-Nuclear-Test-Ban-Treaty monitors the atmosphere for radioactive xenon leaking from underground nuclear explosions. Emissions from medical isotope production represent a challenging background signal when determining whether measured radioxenon in the atmosphere is associated with a nuclear explosion prohibited by the treaty. The Australian Nuclear Science and Technology Organisation (ANSTO) operates a reactor and medical isotope production facility in Lucas Heights, Australia. This study uses two years of release data from the ANSTO medical isotope production facility and Xe-133 data from three IMS sampling locations to estimate the annual releases of Xe-133 from medical isotope production facilities in Argentina, South Africa, and Indonesia. Atmospheric dilution factors derived from a global atmospheric transport model were used in an optimization scheme to estimate annual release values by facility. The annual releases of about 6.8×1014 Bq from the ANSTO medical isotope production facility are in good agreement with the sampled concentrations at these three IMS sampling locations. Annual release estimates for the facility in South Africa vary from 1.2×1016 to 2.5×1016 Bq and estimates for the facility in Indonesia vary from 6.1×1013 to 3.6×1014 Bq. Although some releases from the facility in Argentina may reach these IMS sampling locations, the solution to the objective function is insensitive to the magnitude of those releases.

  12. Characterization of long-range transported Saharan dust at the Caribbean by dual-wavelength depolarization Raman lidar measurements

    NASA Astrophysics Data System (ADS)

    Groß, S.; Freudenthaler, V.; Schepanski, K.; Toledano, C.; Schäfler, A.; Ansmann, A.; Weinzierl, B.

    2015-07-01

    Dual-wavelength Raman and depolarization lidar observations were performed during the SALTRACE campaign at Barbados in June and July 2013 to characterize the optical properties and vertical distribution of long-range transported Saharan dust at the end of its way across the Atlantic Ocean. Four major dust events were studied during the measurements from 15 June to 13 July 2013 with aerosol optical depths of up to 0.6. The vertical aerosol distribution was characterized by a three-layer structure consisting of the boundary layer, the entrainment or mixing layer, and the pure Saharan dust layer. The upper boundary of the pure dust layer reached up to 4.5 km height. The contribution of the pure dust layer was about half of the total AOD. The total dust contribution was about 50-70 % of the total AOD. The lidar ratio within the pure dust layer was found to be wavelength independent with mean values of 53 ± 5 sr at 355 nm and 56 ± 7 sr at 532 nm. For the particle linear depolarization ratio wavelength independent mean values of 0.26 ± 0.03 at 355 nm and 0.27 ± 0.01 at 532 nm have been found.

  13. Measuring and Modeling Solute Transport in the Rootzone: Protecting the Receiving Water Environments of the Coral Atolls of Tonga

    NASA Astrophysics Data System (ADS)

    Clothier, B. E.; van der Velde, M.; Green, S. R.; Gee, G. W.; Manu, V.; Menoniti, V.; Vanclooster, M.

    2005-05-01

    Intensification of agriculture on the raised coral atolls of the Tongan archipelago, notably through squash-pumpkin production, has lead to increased use of agrichemicals. Agrichemicals, both fertilisers and pesticides, pose a risk to these fragile environments. Sustainable land-management practices are needed for small-island developing states. On Tongatapu, solutes leaving the rootzone of the squash can rapidly find their way to the underlying freshwater lenses. These lenses are hydraulically linked to the internal lagoon, and the fringing reefs. We have used buried, non-suction fluxmeters to monitor both the quantity and quality of drainage leaving the rootzone of squash. Fertiliser is traditionally applied at planting. During establishment of the squash in 2003, some 350 mm of rain fell, with 70 % of this leaving the rootzone of this permeable soil as drainage. The concentration of nitrate-N in the drainage water was measured at around 50 mg-N/L. All of the initial fertiliser dressing had been lost, along with N mineralised from the plowed-in grass. Pesticides are needed in humid tropical environments to control weeds, pests and diseases. These chemicals can leach though the rootzone to contaminate receiving waters. We modeled the transport and fate of the presticides used in squash production, and we developed a Decision Support Tool (DST). Our DST can be used to select the best pesticides for local conditions, to tailor practices for minimising leaching losses below the rootzone, and to avoid the build-up of residues in the soil. This project, funded by the European Union and NZAID, took a multi-disciplinary approach through measurement and modeling protocols. Our DST enabled us to engage the wider community and stakeholders. There has been increased awareness of the impacts and risks associated with productive land management in the fragile hydrological environments of this small-island developing state.

  14. Computed Tomography Number Measurement Consistency Under Different Beam Hardening Conditions: Comparison Between Dual-Energy Spectral Computed Tomography and Conventional Computed Tomography Imaging in Phantom Experiment

    PubMed Central

    He, Tian; Qian, Xiaojun; Zhai, Renyou; Yang, Zongtao

    2015-01-01

    Purpose To compare computed tomography (CT) number measurement consistency under different beam hardening conditions in phantom experiment between dual-energy spectral CT and conventional CT imaging. Materials and Methods A phantom with 8 cells in periphery region and 1 cell in central region were used. The 8 conditioning tubes in the periphery region were filled with 1 of the 3 iodine solutions to simulate different beam hardening conditions: 0 for no beam hardening (NBH), 20 mg/mL for weak beam hardening (WBH) and 50 mg/mL for severe beam hardening (SBH) condition. Test tube filled with 0, 0.1, 0.5, 1, 2, 5, 10, 20, and 50 mg/mL iodine solution was placed in the central cell alternately. The phantom was scanned with conventional CT mode with 80, 100, 120, and 140 kVp and dual energy spectral CT mode. For spectral CT, 11 monochromatic image sets from 40 to 140 keV with interval of 10 keV were reconstructed. The CT number shift caused by beam hardening was evaluated by measuring the CT number difference (?CT) with and without beam hardening, with the following formulas: ?CTWBH = |CTWBH ? CTNBH| and ?CTSBH = |CTSBH ? CTNBH|. Data were compared with 1-way analysis of variance. Results Under both WBH and SBH conditions, the CT number shifts in all monochromatic image sets were less than those for polychromatic images (all P < 0.001). Under WBH condition, the maximum CT number shift was less than 6 Hounsfield units for monochromatic spectral CT images of all energy levels; under SBH condition, only monochromatic images at 70 keV and 80 keV had CT number shift less than 6 HU. Conclusion Dual energy spectral CT imaging provided more accurate CT number measurement than conventional CT under various beam hardening conditions. The optimal keV level for monochromatic spectral CT images with the most accurate CT number measurement depends on the severities of beam hardening condition. PMID:26196347

  15. Analysis by oxygen atom number density measurement of high-speed hydrophilic treatment of polyimide using atmospheric pressure microwave plasma

    NASA Astrophysics Data System (ADS)

    Ono, S.

    2015-03-01

    This paper describes the fundamental experimental data of the plasma surface modification of the polyimide using atmospheric pressure microwave plasma source. The experimental results were discussed from the point of view of the radical's behavior, which significantly affects the modification mechanism. The purpose of the study is to examine how the value of the oxygen atom density will affect the hydrophilic treatment in the upstream region of the plasma where gas temperature is very high. The surface modification experiments were performed by setting the polyimide film sample in the downstream region of the plasma. The degree of the modification was measured by a water contact angle measurement. The water contact angle decreased less than 30 degrees within 1 second treatment time in the upstream region. Very high speed modification was observed. The reason of this high speed modification seems that the high density radical which contributes the surface modification exist in the upstream region of the plasma. This tendency is supposed to the measured relatively high electron density (~1015cm-3) at the center of the plasma. We used the electric heating catalytic probe method for oxygen radical measurement. An absolute value of oxygen radical density was determined by catalytic probe measurement and the results show that ~1015cm-3 of the oxygen radical density in the upstream region and decreases toward downstream region. The experimental results of the relation of the oxygen radical density and hydrophilic modification of polyimide was discussed.

  16. Analysis by oxygen atom number density measurement of high-speed hydrophilic treatment of polyimide using atmospheric pressure microwave plasma

    SciTech Connect

    Ono, S.

    2015-03-30

    This paper describes the fundamental experimental data of the plasma surface modification of the polyimide using atmospheric pressure microwave plasma source. The experimental results were discussed from the point of view of the radical’s behavior, which significantly affects the modification mechanism. The purpose of the study is to examine how the value of the oxygen atom density will affect the hydrophilic treatment in the upstream region of the plasma where gas temperature is very high. The surface modification experiments were performed by setting the polyimide film sample in the downstream region of the plasma. The degree of the modification was measured by a water contact angle measurement. The water contact angle decreased less than 30 degrees within 1 second treatment time in the upstream region. Very high speed modification was observed. The reason of this high speed modification seems that the high density radical which contributes the surface modification exist in the upstream region of the plasma. This tendency is supposed to the measured relatively high electron density (~10{sup 15}cm{sup ?3}) at the center of the plasma. We used the electric heating catalytic probe method for oxygen radical measurement. An absolute value of oxygen radical density was determined by catalytic probe measurement and the results show that ~10{sup 15}cm{sup ?3} of the oxygen radical density in the upstream region and decreases toward downstream region. The experimental results of the relation of the oxygen radical density and hydrophilic modification of polyimide was discussed.

  17. Single particle counting diagnostic system for measuring fine particulates at high number densities in research and industrial applications. Final report summarizing instrument development, validation and operating instructions

    SciTech Connect

    Holve, D.J.

    1983-10-01

    Optical methods for particle size distribution measurements in practical high temperature environments have achieved feasibility and offer significant advantages over conventional sampling methods. The present report describes a mobile electro-optical system which has been designed for general use in a wide range of research and industrial environments. Specific features of this system include a method of providing in situ alignment and incorporation of an extinction measurement for application to optically thick aerosol flows. The instrument has demonstrated capability for measuring individual particles in the size range 0.25 to 100 microns at number densities up to 10/sup 12//m/sup 3/. In addition to demonstration of the system's wide dynamic range, we show the utility of the in situ alignment method in hot (1100 K) turbulent flows where beam steering can be a problem. As an example of the instrument's application, number and mass frequency distribution measurements of flyash and pulverized coal obtained in an atmospheric combustion exhaust simulator show that the raw pulverized coal contains large numbers of submicron particles similar to the flyash formed after combustion.

  18. Solar Resource Measurements at FPL Energy - Equipment Only. Cooperative Research and Development Final Report, CRADA Number CRD-08-283

    SciTech Connect

    Dooraghi, Mike

    2015-05-07

    Site-specific, long-term, continuous, and high-resolution measurements of solar irradiance are important for developing renewable resource data. These data are used for several research and development activities consistent with the NREL mission: Establish a national 30-year climatological database of measured solar irradiances; Provide high quality ground-truth data for satellite remote sensing validation; Support development of radiative transfer models for estimating solar irradiance from available meteorological observations; Provide solar resource information needed for technology deployment and operations.

  19. Transport properties investigation of aqueous protic ionic liquid solutions through conductivity, viscosity, and NMR self-diffusion measurements.

    PubMed

    Anouti, Mérièm; Jacquemin, Johan; Porion, Patrice

    2012-04-12

    We present a study on the transport properties through conductivity (?), viscosity (?), and self-diffusion coefficient (D) measurements of two pure protic ionic liquids--pyrrolidinium hydrogen sulfate, [Pyrr][HSO(4)], and pyrrolidinium trifluoroacetate, [Pyrr][CF(3)COO]--and their mixtures with water over the whole composition range at 298.15 K and atmospheric pressure. Based on these experimental results, transport mobilities of ions have been then investigated in each case through the Stokes-Einstein equation. From this, the proton conduction in these PILs follows a combination of Grotthuss and vehicle-type mechanisms, which depends also on the water composition in solution. In each case, the displacement of the NMR peak attributed to the labile proton on the pyrrolidinium cation with the PILs concentration in aqueous solution indicates that this proton is located between the cation and the anion for a water weight fraction lower than 8%. In other words, for such compositions, it appears that this labile proton is not solvated by water molecules. However, for higher water content, the labile protons are in solution as H(3)O(+). This water weight fraction appears to be the solvation limit of the H(+) ions by water molecules in these two PILs solutions. However, [Pyrr][HSO(4)] and [Pyrr][CF(3)COO] PILs present opposed comportment in aqueous solution. In the case of [Pyrr][CF(3)COO], ?, ?, D, and the attractive potential, E(pot), between ions indicate clearly that the diffusion of each ion is similar. In other words, these ions are tightly bound together as ion pairs, reflecting in fact the importance of the hydrophobicity of the trifluoroacetate anion, whereas, in the case of the [Pyrr][HSO(4)], the strong H-bond between the HSO(4)(-) anion and water promotes a drastic change in the viscosity of the aqueous solution, as well as on the conductivity which is up to 187 mS·cm(-1) for water weight fraction close to 60% at 298 K. PMID:22404286

  20. Heat Transfer and Pressure Drop Measurement for Square Channels with V-shape Ribs at High Reynolds Numbers 

    E-print Network

    Alkhamis, Nawaf Yahya

    2010-10-12

    Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee, Je C Han Committee Members, Mahmoud El-Halwagi Sai Lau Head... Abdulaziz University Chair of Advisory: Dr. Je C Han In previous studies, the thermal performance of ribbed channels was studied for Reynolds numbers up to 100,000 with different rib shapes. In more recent studies, the thermal performance of ribbed...