Assessing Strain Mapping by Electron Backscatter Diffraction and Confocal Raman Microscopy Using Wedge-indented Si

PubMed Central

Friedman, Lawrence H.; Vaudin, Mark D.; Stranick, Stephan J.; Stan, Gheorghe; Gerbig, Yvonne B.; Osborn, William; Cook, Robert F.

2016-01-01

The accuracy of electron backscatter diffraction (EBSD) and confocal Raman microscopy (CRM) for small-scale strain mapping are assessed using the multi-axial strain field surrounding a wedge indentation in Si as a test vehicle. The strain field is modeled using finite element analysis (FEA) that is adapted to the near-indentation surface profile measured by atomic force microscopy (AFM). The assessment consists of (1) direct experimental comparisons of strain and deformation and (2) comparisons in which the modeled strain field is used as an intermediate step. Direct experimental methods (1) consist of comparisons of surface elevation and gradient measured by AFM and EBSD and of Raman shifts measured and predicted by CRM and EBSD, respectively. Comparisons that utilize the combined FEA-AFM model (2) consist of predictions of distortion, strain, and rotation for comparison with EBSD measurements and predictions of Raman shift for comparison with CRM measurements. For both EBSD and CRM, convolution of measurements in depth-varying strain fields is considered. The interconnected comparisons suggest that EBSD was able to provide an accurate assessment of the wedge indentation deformation field to within the precision of the measurements, approximately 2 × 10−4 in strain. CRM was similarly precise, but was limited in accuracy to several times this value. PMID:26939030

The accuracy of confrontation visual field test in comparison with automated perimetry.

PubMed Central

Johnson, L. N.; Baloh, F. G.

1991-01-01

The accuracy of confrontation visual field testing was determined for 512 visual fields using automated static perimetry as the reference standard. The sensitivity of confrontation testing excluding patchy defects was 40% for detecting anterior visual field defects, 68.3% for posterior defects, and 50% for both anterior and posterior visual field defects combined. The sensitivity within each group varied depending on the type of visual field defect encountered. Confrontation testing had a high sensitivity (75% to 100%) for detecting altitudinal visual loss, central/centrocecal scotoma, and homonymous hemianopsia. Confrontation testing was fairly insensitive (20% to 50% sensitivity) for detecting arcuate scotoma and bitemporal hemianopsia. The specificity of confrontation testing was high at 93.4%. The high positive predictive value (72.6%) and negative predictive value (75.7%) would indicate that visual field defects identified during confrontation testing are often true visual field defects. However, the many limitations of confrontation testing should be remembered, particularly its low sensitivity for detecting visual field loss associated with parasellar tumors, glaucoma, and compressive optic neuropathies. PMID:1800764

Is Higher Better? Determinants and Comparisons of Performance on the Major Field Test in Business

ERIC Educational Resources Information Center

Bielinska-Kwapisz, Agnieszka; Brown, F. William; Semenik, Richard

2012-01-01

Student performance on the Major Field Achievement Test in Business is an important benchmark for college of business programs. The authors' results indicate that such benchmarking can only be meaningful if certain student characteristics are taken into account. The differences in achievement between cohorts are explored in detail by separating…

Comparison between simulations and lab results on the ASSIST test-bench

NASA Astrophysics Data System (ADS)

Le Louarn, Miska; Madec, Pierre-Yves; Kolb, Johann; Paufique, Jerome; Oberti, Sylvain; La Penna, Paolo; Arsenault, Robin

2016-07-01

We present the latest comparison results between laboratory tests carried out on the ASSIST test bench and Octopus end-to end simulations. We simulated, as closely to the lab conditions as possible, the different AOF modes (Maintenance and commissioning mode (SCAO), GRAAL (GLAO in the near IR), Galacsi Wide Field mode (GLAO in the visible) and Galacsi narrow field mode (LTAO in the visible)). We then compared the simulation results to the ones obtained on the lab bench. Several aspects were investigated, like number of corrected modes, turbulence wind speeds, LGS photon flux etc. The agreement between simulations and lab is remarkably good for all investigated parameters, giving great confidence in both simulation tool and performance of the AO system in the lab.

Comparison of performance of wood extractives as preservatives in field tests against termites and decay in the USA and Pakistan

Treesearch

Babar Hassan; Sohail Ahmed; Mark Mankowski; Grant Kirker

2017-01-01

Increasing environmental regulations have limited the use of certain broad spectrum synthetic pesticides as wood preservatives creating a need for more environmentally benign wood preservative systems. Biocidal compounds from natural products have been proposed as alternatives to commercial wood preservatives, but field data from long term performance testing is...

Threshold and variability properties of matrix frequency-doubling technology and standard automated perimetry in glaucoma.

PubMed

Artes, Paul H; Hutchison, Donna M; Nicolela, Marcelo T; LeBlanc, Raymond P; Chauhan, Balwantray C

2005-07-01

To compare test results from second-generation Frequency-Doubling Technology perimetry (FDT2, Humphrey Matrix; Carl-Zeiss Meditec, Dublin, CA) and standard automated perimetry (SAP) in patients with glaucoma. Specifically, to examine the relationship between visual field sensitivity and test-retest variability and to compare total and pattern deviation probability maps between both techniques. Fifteen patients with glaucoma who had early to moderately advanced visual field loss with SAP (mean MD, -4.0 dB; range, +0.2 to -16.1) were enrolled in the study. Patients attended three sessions. During each session, one eye was examined twice with FDT2 (24-2 threshold test) and twice with SAP (Swedish Interactive Threshold Algorithm [SITA] Standard 24-2 test), in random order. We compared threshold values between FDT2 and SAP at test locations with similar visual field coordinates. Test-retest variability, established in terms of test-retest intervals and standard deviations (SDs), was investigated as a function of visual field sensitivity (estimated by baseline threshold and mean threshold, respectively). The magnitude of visual field defects apparent in total and pattern deviation probability maps were compared between both techniques by ordinal scoring. The global visual field indices mean deviation (MD) and pattern standard deviation (PSD) of FDT2 and SAP correlated highly (r > 0.8; P < 0.001). At test locations with high sensitivity (>25 dB with SAP), threshold estimates from FDT2 and SAP exhibited a close, linear relationship, with a slope of approximately 2.0. However, at test locations with lower sensitivity, the relationship was much weaker and ceased to be linear. In comparison with FDT2, SAP showed a slightly larger proportion of test locations with absolute defects (3.0% vs. 2.2% with SAP and FDT2, respectively, P < 0.001). Whereas SAP showed a significant increase in test-retest variability at test locations with lower sensitivity (P < 0.001), there was no relationship between variability and sensitivity with FDT2 (P = 0.46). In comparison with SAP, FDT2 exhibited narrower test-retest intervals at test locations with lower sensitivity (SAP thresholds <25 dB). A comparison of the total and pattern deviation maps between both techniques showed that the total deviation analyses of FDT2 may slightly underestimate the visual field loss apparent with SAP. However, the pattern-deviation maps of both instruments agreed well with each other. The test-retest variability of FDT2 is uniform over the measurement range of the instrument. These properties may provide advantages for the monitoring of patients with glaucoma that should be investigated in longitudinal studies.

Comparison of results of an obstacle resolving microscale model with wind tunnel data

NASA Astrophysics Data System (ADS)

Grawe, David; Schlünzen, K. Heinke; Pascheke, Frauke

2013-11-01

The microscale transport and stream model MITRAS has been improved and a new technique has been implemented to improve numerical stability for complex obstacle configurations. Results of the updated version have been compared with wind tunnel data using an evaluation method that has been established for simple obstacle configurations. MITRAS is a part of the M-SYS model system for the assessment of ambient air quality. A comparison of model results for the flow field against quality ensured wind tunnel data has been carried out for both idealised and realistic test cases. Results of the comparison show a very good agreement of the wind field for most test cases and identify areas of possible improvement of the model. The evaluated MITRAS results can be used as input data for the M-SYS microscale chemistry model MICTM. This paper describes how such a comparison can be carried out for simple as well as realistic obstacle configurations and what difficulties arise.

Field evaluation of Wisconsin modified binder selection guidelines - phase II.

DOT National Transportation Integrated Search

2013-12-01

The purpose of this project was to continue phase I of the study with the objective of identifying promising procedures and applicable modified binder specification criteria for use in Wisconsin, based on comparison of test results to field performan...

Comparing the field and laboratory emission cell (FLEC) with traditional emissions testing chambers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roache, N.F.; Guo, Z.; Fortmann, R.

1996-12-31

A series of tests was designed to evaluate the performance of the field and laboratory emission cell (FLEC) as applied to the testing of emissions from two indoor coating materials, floor wax and latex paint. These tests included validation of the repeatability of the test method, evaluation of the effect of different air velocities on source emissions, and a comparison of FLEC versus small chamber characterization of emissions. The FLEC exhibited good repeatability in characterization of emissions when applied to both sources under identical conditions. Tests with different air velocities showed significant effects on the emissions from latex paint, yetmore » little effect on emissions from the floor wax. Comparisons of data from the FLEC and small chamber show good correlation for measurements involving floor wax, but less favorable results for emissions from latex paint. The procedures and findings are discussed; conclusions are limited and include emphasis on the need for additional study and development of a standard method.« less

The validity of three tests of temperament in guppies (Poecilia reticulata).

PubMed

Burns, James G

2008-11-01

Differences in temperament (consistent differences among individuals in behavior) can have important effects on fitness-related activities such as dispersal and competition. However, evolutionary ecologists have put limited effort into validating their tests of temperament. This article attempts to validate three standard tests of temperament in guppies: the open-field test, emergence test, and novel-object test. Through multiple reliability trials, and comparison of results between different types of test, this study establishes the confidence that can be placed in these temperament tests. The open-field test is shown to be a good test of boldness and exploratory behavior; the open-field test was reliable when tested in multiple ways. There were problems with the emergence test and novel-object test, which leads one to conclude that the protocols used in this study should not be considered valid tests for this species. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

Evaluation of interaction properties of geosynthetics in cohesive soils : LTRC reinforced soil test wall : technical summary.

DOT National Transportation Integrated Search

2004-07-01

The test wall was constructed to evaluate the behavior of MSE walls constructed with silty-clay soils through comparison between predicted and field measurements. The primary objectives of the construction of the LTRC reinforced test wall were to mon...

A comparison of blood alcohol levels as determined by breath and blood tests taken in actual field operations.

DOT National Transportation Integrated Search

1972-01-01

During its 1972 session, the General Assembly of Virginia enacted Senate Bill 104, which authorizes the breath test, as well as the blood test used previously, as a proper chemical test to determine the alcoholic content of the blood. Any person arre...

Comparing State-Space Multivariable Controls to Multi-SISO Controls for Load Reduction of Drivetrain-Coupled Modes on Wind Turbines Through Field-Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleming, P. A.; Van Wingerden, J. W.; Wright, A. D.

2012-01-01

In this paper we present results from an ongoing controller comparison study at the National Renewable Energy Laboratory's (NREL's) National Wind Technology Center (NWTC). The intention of the study is to demonstrate the advantage of using modern multivariable methods for designing control systems for wind turbines versus conventional approaches. We will demonstrate the advantages through field-test results from experimental turbines located at the NWTC. At least two controllers are being developed side-by-side to meet an incrementally increasing number of turbine load-reduction objectives. The first, a multiple single-input, single-output (m-SISO) approach, uses separately developed decoupled and classicially tuned controllers, which is,more » to the best of our knowledge, common practice in the wind industry. The remaining controllers are developed using state-space multiple-input and multiple-output (MIMO) techniques to explicity account for coupling between loops and to optimize given known frequency structures of the turbine and disturbance. In this first publication from the study, we present the structure of the ongoing controller comparison experiment, the design process for the two controllers compared in this phase, and initial comparison results obtained in field-testing.« less

Comparison of current meters used for stream gaging

USGS Publications Warehouse

Fulford, Janice M.; Thibodeaux, Kirk G.; Kaehrle, William R.

1994-01-01

The U.S. Geological Survey (USGS) is field and laboratory testing the performance of several current meters used throughout the world for stream gaging. Meters tested include horizontal-axis current meters from Germany, the United Kingdom, and the People's Republic of China, and vertical-axis and electromagnetic current meters from the United States. Summarized are laboratory test results for meter repeatability, linearity, and response to oblique flow angles and preliminary field testing results. All current meters tested were found to under- and over-register velocities; errors usually increased as the velocity and angle of the flow increased. Repeatability and linearity of all meters tested were good. In the field tests, horizontal-axis meters, except for the two meters from the People's Republic of China, registered higher velocity than did the vertical-axis meters.

Verification of a 2 kWe Closed-Brayton-Cycle Power Conversion System Mechanical Dynamics Model

NASA Technical Reports Server (NTRS)

Ludwiczak, Damian R.; Le, Dzu K.; McNelis, Anne M.; Yu, Albert C.; Samorezov, Sergey; Hervol, Dave S.

2005-01-01

Vibration test data from an operating 2 kWe closed-Brayton-cycle (CBC) power conversion system (PCS) located at the NASA Glenn Research Center was used for a comparison with a dynamic disturbance model of the same unit. This effort was performed to show that a dynamic disturbance model of a CBC PCS can be developed that can accurately predict the torque and vibration disturbance fields of such class of rotating machinery. The ability to accurately predict these disturbance fields is required before such hardware can be confidently integrated onto a spacecraft mission. Accurate predictions of CBC disturbance fields will be used for spacecraft control/structure interaction analyses and for understanding the vibration disturbances affecting the scientific instrumentation onboard. This paper discusses how test cell data measurements for the 2 kWe CBC PCS were obtained, the development of a dynamic disturbance model used to predict the transient torque and steady state vibration fields of the same unit, and a comparison of the two sets of data.

(Full field) optical coherence tomography and applications

NASA Astrophysics Data System (ADS)

Buchroithner, Boris; Hannesschläger, Günther; Leiss-Holzinger, Elisabeth; Prylepa, Andrii; Heise, Bettina

2018-03-01

This paper illustrates specific features and use of optical coherence tomography (OCT) in the raster-scanning and in comparison in the full field version of this imaging technique. Cases for nondestructive testing are discussed alongside other application schemes. In particular monitoring time-dependent processes and probing of birefringent specimens are considered here. In the context of polymer testing birefringence mapping may often provide information about internal strain and stress states. Recent results obtained with conventional raster-scanning OCT systems, with (dual and single-shot) full field OCT configurations, and with polarization-sensitive versions of (full field) OCT are presented here.

Leaching Test Relationships, Laboratory-to-Field Comparisons and Recommendations for Leaching Evaluation using the Leaching Environmental Assessment Framework (LEAF)

EPA Science Inventory

This report presents examples of the relationships between the results of laboratory leaching tests, as defined by the Leaching Environmental Assessment Framework (LEAF) or analogous international test methods, and leaching of constituents from a broad range of materials under di...

Development of a quality control test procedure for characterizing fracture properties of asphalt mixtures.

DOT National Transportation Integrated Search

2011-06-01

The main objective of this study is to investigate the use of the semi-circular bend (SCB) : test as a quality assurance/quality control (QA/QC) measure for field construction. : Comparison of fracture properties from the SCB test and fatigue beam te...

An Acoustical Comparison of Sub-Scale and Full-Scale Far-Field Measurements for the Reusable Solid Rocket Motor

NASA Technical Reports Server (NTRS)

Haynes, Jared; Kenny, R. Jeremy

2010-01-01

Recently, members of the Marshall Space Flight Center (MSFC) Fluid Dynamics Branch and Wyle Labs measured far-field acoustic data during a series of three Reusable Solid Rocket Motor (RSRM) horizontal static tests conducted in Promontory, Utah. The test motors included the Technical Evaluation Motor 13 (TEM-13), Flight Verification Motor 2 (FVM-2), and the Flight Simulation Motor 15 (FSM-15). Similar far-field data were collected during horizontal static tests of sub-scale solid rocket motors at MSFC. Far-field acoustical measurements were taken at multiple angles within a circular array centered about the nozzle exit plane, each positioned at a radial distance of 80 nozzle-exit-diameters from the nozzle. This type of measurement configuration is useful for calculating rocket noise characteristics such as those outlined in the NASA SP-8072 "Acoustic Loads Generated by the Propulsion System." Acoustical scaling comparisons are made between the test motors, with particular interest in the Overall Sound Power, Acoustic Efficiency, Non-dimensional Relative Sound Power Spectrum, and Directivity. Since most empirical data in the NASA SP-8072 methodology is derived from small rockets, this investigation provides an opportunity to check the data collapse between a sub-scale and full-scale rocket motor.

Environmental requirements for flat plate photovoltaic modules for terrestrial applications

NASA Technical Reports Server (NTRS)

Hoffman, A. R.; Ross, R. G., Jr.

1979-01-01

The environmental test requirements that have been developed for flat plate modules purchased through Department of Energy funding are described. Concurrent with the selection of the initial qualification tests from space program experience - temperature cycling and humidity - surveys of existing photovoltaic systems in the field revealed that arrays were experiencing the following failure modes: interconnect breakage, delamination, and electrical termination corrosion. These coupled with application-dependent considerations led to the development of additional qualification tests, such as cyclic pressure loading, warped mounting surface, and hail. Rationale for the selection of tests, their levels and durations is described. Comparisons between field-observed degradation and test-induced degradation show a positive correlation with some of the observed field effects. Also, the tests are proving useful for detecting design, process, and workmanship deficiencies. The status of study efforts for the development of environmental requirements for field-related problems is reviewed.

Validation of the Puumala virus rapid field test for bank voles in Germany.

PubMed

Reil, D; Imholt, C; Rosenfeld, U M; Drewes, S; Fischer, S; Heuser, E; Petraityte-Burneikiene, R; Ulrich, R G; Jacob, J

2017-02-01

Puumala virus (PUUV) causes many human infections in large parts of Europe and can lead to mild to moderate disease. The bank vole (Myodes glareolus) is the only reservoir of PUUV in Central Europe. A commercial PUUV rapid field test for rodents was validated for bank-vole blood samples collected in two PUUV-endemic regions in Germany (North Rhine-Westphalia and Baden-Württemberg). A comparison of the results of the rapid field test and standard ELISAs indicated a test efficacy of 93-95%, largely independent of the origin of the antigens used in the ELISA. In ELISAs, reactivity for the German PUUV strain was higher compared to the Swedish strain but not compared to the Finnish strain, which was used for the rapid field test. In conclusion, the use of the rapid field test can facilitate short-term estimation of PUUV seroprevalence in bank-vole populations in Germany and can aid in assessing human PUUV infection risk.

Determination of MLC model parameters for Monaco using commercial diode arrays.

PubMed

Kinsella, Paul; Shields, Laura; McCavana, Patrick; McClean, Brendan; Langan, Brian

2016-07-08

Multileaf collimators (MLCs) need to be characterized accurately in treatment planning systems to facilitate accurate intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT). The aim of this study was to examine the use of MapCHECK 2 and ArcCHECK diode arrays for optimizing MLC parameters in Monaco X-ray voxel Monte Carlo (XVMC) dose calculation algorithm. A series of radiation test beams designed to evaluate MLC model parameters were delivered to MapCHECK 2, ArcCHECK, and EBT3 Gafchromic film for comparison. Initial comparison of the calculated and ArcCHECK-measured dose distributions revealed it was unclear how to change the MLC parameters to gain agreement. This ambiguity arose due to an insufficient sampling of the test field dose distributions and unexpected discrepancies in the open parts of some test fields. Consequently, the XVMC MLC parameters were optimized based on MapCHECK 2 measurements. Gafchromic EBT3 film was used to verify the accuracy of MapCHECK 2 measured dose distributions. It was found that adjustment of the MLC parameters from their default values resulted in improved global gamma analysis pass rates for MapCHECK 2 measurements versus calculated dose. The lowest pass rate of any MLC-modulated test beam improved from 68.5% to 93.5% with 3% and 2 mm gamma criteria. Given the close agreement of the optimized model to both MapCHECK 2 and film, the optimized model was used as a benchmark to highlight the relatively large discrepancies in some of the test field dose distributions found with ArcCHECK. Comparison between the optimized model-calculated dose and ArcCHECK-measured dose resulted in global gamma pass rates which ranged from 70.0%-97.9% for gamma criteria of 3% and 2 mm. The simple square fields yielded high pass rates. The lower gamma pass rates were attributed to the ArcCHECK overestimating the dose in-field for the rectangular test fields whose long axis was parallel to the long axis of the ArcCHECK. Considering ArcCHECK measurement issues and the lower gamma pass rates for the MLC-modulated test beams, it was concluded that MapCHECK 2 was a more suitable detector than ArcCHECK for the optimization process. © 2016 The Authors

Resistance and cross-resistance in populations of the leafrollers, Choristoneura rosaceana and Pandemis pyrusana, in Washington apples

PubMed Central

Dunley, John E.; Brunner, Jay F.; Doerr, Michael D.; Beers, E. H.

2006-01-01

Insecticide bioassays of the leafrollers, Choristoneura rosaceana (Harris), and Pandemis pyrusana Kearfott (Lepidoptera: Tortricidae), were used to investigate resistance and cross-resistance between azinphosmethyl and other insecticides. Comparisons of field-collected populations with susceptible laboratory colonies of both leafroller species were made in 1996–97, prior to registration and field introduction of several of insecticides, and were re-tested in 2000–2001 following several years of use in the field. Insecticides tested included azinphosmethyl, chlorpyrifos, methyl parathion, tebufenozide, methoxyfenozide, spinosad, indoxacarb, acetamiprid, Bacillus thuringiensis, and azadirachtin. Azinphosmethyl-susceptible laboratory colonies were used for comparison to field populations. Resistance to azinphosmethyl was found in all populations of C. rosaceana (5.2–26.8 fold) and P. pyrusana (8.4–24.9 fold) collected from commercial orchards. Cross-resistance between azinphosmethyl and the insect growth regulators tebufenozide and methoxyfenozide was found in all but one population of the two leafroller species. No cross-resistance was found to chlorpyrifos. Some of the populations tested were cross-resistant to spinosad and indoxacarb, but the responses to these materials were more variable. PMID:19537964

A Comparison of High-Energy Electron and Cobalt-60 Gamma-Ray Radiation Testing

NASA Technical Reports Server (NTRS)

Boutte, Alvin J.; Campola, Michael J.; Carts, Martin A.; Wilcox, Edward P.; Marshall, Cheryl J.; Phan, Anthony M.; Pellish, Jonathan A.; Powell, Wesley A.; Xapsos, Michael A.

2012-01-01

In this paper, a comparison between the effects of irradiating microelectronics with high energy electrons and Cobalt-60 gamma-rays is examined. Additionally, the effect of electron energy is also discussed. A variety of part types are investigated, including discrete bipolar transistors, hybrids, and junction field effect transistors

Mass Trapping for Anastrepha suspensa

USDA-ARS?s Scientific Manuscript database

ABSTRACT In field tests conducted in south Florida to test grape juice as an alternative inexpensive bait for Anastrepha suspensa Loew, high numbers of Zaprionus indianus Gupta were captured in traps baited with aqueous grape juice. These experiments included comparisons of grape juice with standard...

FIELD TEST OF CYCLODEXTRIN FOR ENHANCED IN-SITU FLUSHING OF MULTIPLE-COMPONENT IMMISCIBLE ORGANIC LIQUID CONTAMINATION: COMPARISON TO WATER FLUSHING

EPA Science Inventory

A pilot-scale field experiment was conducted to compare the remediation effectiveness of an enhanced-solubilization technique to that of water flushing for removal of multicomponent nonaqueous-phase organic liquid (NAPL) contaminants form a phreatic aquifer. This innovative remed...

Field demonstration of CO2 leakage detection in potable aquifers with a pulselike CO2-release test.

PubMed

Yang, Changbing; Hovorka, Susan D; Delgado-Alonso, Jesus; Mickler, Patrick J; Treviño, Ramón H; Phillips, Straun

2014-12-02

This study presents two field pulselike CO2-release tests to demonstrate CO2 leakage detection in a shallow aquifer by monitoring groundwater pH, alkalinity, and dissolved inorganic carbon (DIC) using the periodic groundwater sampling method and a fiber-optic CO2 sensor for real-time in situ monitoring of dissolved CO2 in groundwater. Measurements of groundwater pH, alkalinity, DIC, and dissolved CO2 clearly deviated from their background values, showing responses to CO2 leakage. Dissolved CO2 observed in the tests was highly sensitive in comparison to groundwater pH, DIC, and alkalinity. Comparison of the pulselike CO2-release tests to other field tests suggests that pulselike CO2-release tests can provide reliable assessment of geochemical parameters indicative of CO2 leakage. Measurements by the fiber-optic CO2 sensor, showing obvious leakage signals, demonstrated the potential of real-time in situ monitoring of dissolved CO2 for leakage detection at a geologic carbon sequestration (GCS) site. Results of a two-dimensional reactive transport model reproduced the geochemical measurements and confirmed that the decrease in groundwater pH and the increases in DIC and dissolved CO2 observed in the pulselike CO2-release tests were caused by dissolution of CO2 whereas alkalinity was likely affected by carbonate dissolution.

Mass univariate analysis of event-related brain potentials/fields I: a critical tutorial review.

PubMed

Groppe, David M; Urbach, Thomas P; Kutas, Marta

2011-12-01

Event-related potentials (ERPs) and magnetic fields (ERFs) are typically analyzed via ANOVAs on mean activity in a priori windows. Advances in computing power and statistics have produced an alternative, mass univariate analyses consisting of thousands of statistical tests and powerful corrections for multiple comparisons. Such analyses are most useful when one has little a priori knowledge of effect locations or latencies, and for delineating effect boundaries. Mass univariate analyses complement and, at times, obviate traditional analyses. Here we review this approach as applied to ERP/ERF data and four methods for multiple comparison correction: strong control of the familywise error rate (FWER) via permutation tests, weak control of FWER via cluster-based permutation tests, false discovery rate control, and control of the generalized FWER. We end with recommendations for their use and introduce free MATLAB software for their implementation. Copyright © 2011 Society for Psychophysiological Research.

Comparison of DIC and LDV for practical vibration and modal measurements

NASA Astrophysics Data System (ADS)

Reu, Phillip L.; Rohe, Daniel P.; Jacobs, Laura D.

2017-03-01

We compare laser Doppler vibrometry (LDV) and digital image correlation (DIC) for use in full-field vibration and modal testing. This was done using a simultaneously measured 3D displacement field on a flat 7-in. corner-supported metal plate using pseudorandom excitation via a shaker. We complete a detailed comparison between the techniques and discuss the pros and cons of each. The results show that either technique can be used for quantifying the modal information with the LDV providing better out-of-plane displacement resolution and equivalent in-plane resolution. The strain calculation is considered better in the DIC approach due to the direct tie to the surface displacements. While the LDV does not lose its place as the gold standard for modal testing, DIC has introduced a new and competitive approach that will have significant advantages in certain testing regimes.

Field testing energy-saving hermetic compressors in residential refrigerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sauber, R.S.; Middleton, M.G.

The design of an energy-saving compressor for low back pressure applications is reviewed. Calorimeter performance results are stated for two sizes of the efficient design and compared with performance test results for a standard compressor. Power consumption of a refrigerator-freezer is given with a standard compressor and with the energy-saving compressor. The preparation of the refrigerators used in the field test is discussed, along with the criteria used in selecting the instrumentation for the project. Results of the energy-saving compressor in the field test, along with a comparison to a standard production compressor, are presented. Some conclusions are drawn, basedmore » on the data, in relation to important factors in residential refrigerator power consumption.« less

Field testing energy-saving hermetic compressors in residential refrigerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sauber, R.S.; Middleton, M.G.

The design of an energy saving compressor for low back pressure applications is reviewed. Calorimeter performance results are stated for two sizes of the efficient design and compared with performance test results for a standard compressor. Power consumption of a refrigerator-freezer is given with a standard compressor and with the energy saving compressor. The preparation of the refrigerators used in the field test are discussed along with the criteria used in selecting the instrumentation for the project. Results of the energy saving compressor in the field test along with a comparison to a standard production compressor are presented. Some conclusionsmore » are drawn, based on the data, in relation to important factors in residential refrigerator power consumption.« less

Comparison of Three Wind Measuring Systems for Flight Test

NASA Technical Reports Server (NTRS)

Teets, Edward H., Jr.; Harvey, Philip O.

2000-01-01

A preliminary field test of the accuracy of wind velocity measurements obtained using global positioning system-tracked rawinsonde balloons has been performed. Wind comparisons have been conducted using global positioning system (GPS) and radio automatic theodolite sounder (RATS) rawinsondes and a high-precision range instrumentation radar-tracked reflector. Wind velocity differences between the GPS rawinsondes and the radar were significantly less than between the RATS rawinsondes and the radar. These limited test results indicate a root-mean-square wind velocity difference from 4.98 kn (2.56 m/sec) for the radar and RATS to 1.09 kn (0.56 m/sec) for the radar and GPS. Differences are influenced by user reporting requirements, data processing techniques, and the inherent tracking accuracies of the system. This brief field test indicates that the GPS sounding system tracking data are more precise than the RATS system. When high-resolution wind data are needed, use of GPS rawinsonde systems can reduce the burden on range radar operations.

A Comparison of Student Spatial Abilities Across STEM Fields

NASA Astrophysics Data System (ADS)

Loftis, Thad; Cid, Xiimena; Lopez, Ramon

2011-10-01

It has been shown that STEM (Science, Technology, Engineering, and Mathematics) students have higher spatial abilities than students in the liberal arts or humanities. In order to track the change in spatial abilities within a group, studies in physics have examined topics in kinematics, chemistry has examined topics on molecular diagrams, mathematics has examined topics related to geometry, and engineering has developed courses specifically targeting students' spatial abilities. It is understood that students in STEM fields improve their spatial abilities while taking STEM courses, but very few studies have done comparisons amongst the different STEM fields. I will be presenting data comparing different STEM students' spatial ability, assessed using the Mental Rotation Test.

Simple Statistical Model to Quantify Maximum Expected EMC in Spacecraft and Avionics Boxes

NASA Technical Reports Server (NTRS)

Trout, Dawn H.; Bremner, Paul

2014-01-01

This study shows cumulative distribution function (CDF) comparisons of composite a fairing electromagnetic field data obtained by computational electromagnetic 3D full wave modeling and laboratory testing. Test and model data correlation is shown. In addition, this presentation shows application of the power balance and extention of this method to predict the variance and maximum exptected mean of the E-field data. This is valuable for large scale evaluations of transmission inside cavities.

Maintenance of reference standards in the field of viscosity

NASA Astrophysics Data System (ADS)

Moşulică, E. A.; Cîrneanu, I.; Constantin, N.; Rucai, V.

2018-01-01

Participation in the work of comparison in the field of viscosity, within the program conducted under the jurisdiction of ASTM (American Society for Testing and Materials), D-2 Committee, Subcommittee "Flow Properties," Newtonian Fluids) was necessary to ensure traceability of measuring unit of kinematic viscosity. Results of the comparison of the specialized participating laboratories on 4 continents, has proved annual capability of INM in the transmission unit of kinematic viscosity. Cannon Position Company in the US organizes co-operation program in the field of kinematic viscosity ASTM D 02.07. The company distributes standard substances Cannon viscosity participating laboratories and consolidate the results of the measurements. Physical-chemical laboratory has fully accepted the proposed schedule of the company Cannon. Final report of the comparison showed that in the year 2015 a number of 25 laboratories and institutes of metrology attented to the program.

Testing electrostatic equilibrium in the ionosphere by detailed comparison of ground magnetic deflection and incoherent scatter radar.

NASA Astrophysics Data System (ADS)

Cosgrove, R. B.; Schultz, A.; Imamura, N.

2016-12-01

Although electrostatic equilibrium is always assumed in the ionosphere, there is no good theoretical or experimental justification for the assumption. In fact, recent theoretical investigations suggest that the electrostatic assumption may be grossly in error. If true, many commonly used modeling methods are placed in doubt. For example, the accepted method for calculating ionospheric conductance??field line integration??may be invalid. In this talk we briefly outline the theoretical research that places the electrostatic assumption in doubt, and then describe how comparison of ground magnetic field data with incoherent scatter radar (ISR) data can be used to test the electrostatic assumption in the ionosphere. We describe a recent experiment conducted for the purpose, where an array of magnetometers was temporalily installed under the Poker Flat AMISR.

Comparison of field theory models of interest rates with market data

NASA Astrophysics Data System (ADS)

Baaquie, Belal E.; Srikant, Marakani

2004-03-01

We calibrate and test various variants of field theory models of the interest rate with data from Eurodollar futures. Models based on psychological factors are seen to provide the best fit to the market. We make a model independent determination of the volatility function of the forward rates from market data.

Brittle fracture phase-field modeling of a short-rod specimen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Escobar, Ivana; Tupek, Michael R.; Bishop, Joseph E.

2015-09-01

Predictive simulation capabilities for modeling fracture evolution provide further insight into quantities of interest in comparison to experimental testing. Based on the variational approach to fracture, the advent of phase-field modeling achieves the goal to robustly model fracture for brittle materials and captures complex crack topologies in three dimensions.

Quality control tests of lab-reared Cydia pomonella and Cactoblastis cactorum field performance: Comparison of laboratory and field bioassays.

USDA-ARS?s Scientific Manuscript database

Research, operational, and commercial programs which rely on mass-reared insects of high quality and performance, need accurate methods for monitoring quality degradation during each step of production, handling and release. With continued interest in the use of the sterile insect technique (SIT) a...

Field Comparison of Spruce Budworm Pheromone Lures

Treesearch

David G. Grimble

1987-01-01

Four types of spruce budworm pheromone lures were tested to compare field longevity and efficiency. Biolures with three different pheromone release rates and Silk-PVC lures all caught male budworm moths throughout the moth flight period in proportion to the different release rates. Fumigant strips in traps to kill trapped moths were necessary.

Modeling sand wave characteristics on the Belgian Continental Shelf and in the Calais-Dover Strait

NASA Astrophysics Data System (ADS)

Cherlet, J.; Besio, G.; Blondeaux, P.; van Lancker, V.; Verfaillie, E.; Vittori, G.

2007-06-01

The capability of the model of Besio et al. (2006) to predict the main geometrical characteristics (crest orientation, wavelength,…) of tidal sand waves is tested by comparing the theoretical predictions with field data. In particular the field observations carried out by Mouchet (1990) and Van Lancker et al. (2005) along the continental shelf of Belgium are used. Additional comparisons are carried out against the field measurements described by Le Bot (2001) and Le Bot and Trenteseaux (2004) which were carried out in an adjacent region. Attention is focused on the prediction of the wavelength of the bottom forms. Indeed, the capability of a linear stability analysis to predict the occurrence of sand waves has been already tested by Hulscher and van den Brink (2001) and more recently by van der Veen et al. (2006). The obtained results show that the theoretical predictions fairly agree with field observations even though some of the comparisons suggest that the accuracy of the predictions depends on the accurate evaluation of the local current and sediment characteristics.

Food mechanical properties and dietary ecology.

PubMed

Berthaume, Michael A

2016-01-01

Interdisciplinary research has benefitted the fields of anthropology and engineering for decades: a classic example being the application of material science to the field of feeding biomechanics. However, after decades of research, discordances have developed in how mechanical properties are defined, measured, calculated, and used due to disharmonies between and within fields. This is highlighted by "toughness," or energy release rate, the comparison of incomparable tests (i.e., the scissors and wedge tests), and the comparison of incomparable metrics (i.e., the stress and displacement-limited indices). Furthermore, while material scientists report on a myriad of mechanical properties, it is common for feeding biomechanics studies to report on just one (energy release rate) or two (energy release rate and Young's modulus), which may or may not be the most appropriate for understanding feeding mechanics. Here, I review portions of materials science important to feeding biomechanists, discussing some of the basic assumptions, tests, and measurements. Next, I provide an overview of what is mechanically important during feeding, and discuss the application of mechanical property tests to feeding biomechanics. I also explain how 1) toughness measures gathered with the scissors, wedge, razor, and/or punch and die tests on non-linearly elastic brittle materials are not mechanical properties, 2) scissors and wedge tests are not comparable and 3) the stress and displacement-limited indices are not comparable. Finally, I discuss what data gathered thus far can be best used for, and discuss the future of the field, urging researchers to challenge underlying assumptions in currently used methods to gain a better understanding between primate masticatory morphology and diet. © 2016 Wiley Periodicals, Inc.

Environmental aging in polycrystalline-Si photovoltaic modules: comparison of chamber-based accelerated degradation studies with field-test data

NASA Astrophysics Data System (ADS)

Lai, T.; Biggie, R.; Brooks, A.; Potter, B. G.; Simmons-Potter, K.

2015-09-01

Lifecycle degradation testing of photovoltaic (PV) modules in accelerated-degradation chambers can enable the prediction both of PV performance lifetimes and of return-on-investment for installations of PV systems. With degradation results strongly dependent on chamber test parameters, the validity of such studies relative to fielded, installed PV systems must be determined. In the present work, accelerated aging of a 250 W polycrystalline silicon module is compared to real-time performance degradation in a similar polycrystalline-silicon, fielded, PV technology that has been operating since October 2013. Investigation of environmental aging effects are performed in a full-scale, industrial-standard environmental chamber equipped with single-sun irradiance capability providing illumination uniformity of 98% over a 2 x 1.6 m area. Time-dependent, photovoltaic performance (J-V) is evaluated over a recurring, compressed night-day cycle providing representative local daily solar insolation for the southwestern United States, followed by dark (night) cycling. This cycle is synchronized with thermal and humidity environmental variations that are designed to mimic, as closely as possible, test-yard conditions specific to a 12 month weather profile for a fielded system in Tucson, AZ. Results confirm the impact of environmental conditions on the module long-term performance. While the effects of temperature de-rating can be clearly seen in the data, removal of these effects enables the clear interpretation of module efficiency degradation with time and environmental exposure. With the temperature-dependent effect removed, the normalized efficiency is computed and compared to performance results from another panel of similar technology that has previously experienced identical climate changes in the test yard. Analysis of relative PV module efficiency degradation for the chamber-tested system shows good comparison to the field-tested system with ~2.5% degradation following an equivalent year of testing.

Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage

DTIC Science & Technology

2017-10-01

expected. Statistics: Comparisons were analyzed using ANOVA with Tukey’s post -hoc test (pɘ.05). RESULTS: In study 1, a proportion of synovial...AWARD NUMBER: W81XWH-14-1-0591 TITLE: Electric Field Stimulation Enhances Healing of Post -Traumatic Osteoarthritic Cartilage PRINCIPAL...2016 – 29 Sep 2017 4. TITLE AND SUBTITLE Cartilage 5a. CONTRACT NUMBER Electric Field Stimulation Enhances Healing of Post -Traumatic Osteoarthritic

Comparison of high performance liquid chromatography and enzymatic analysis of soluble carbohydrates in loblolly pine

Treesearch

Patricia L. Faulkner; Michele M. Schoeneberger; Kim H. Ludovici

1993-01-01

Foliar tissue was collected from a field study designed to test impacts of atmospheric pollutants on loblolIy pine (Pinus taeda L.) seedlings. Standard enzymatic (ENZ) and high performance liquid chromatography (HPLC) methods were used to analyze the tissue for soluble sugars. A comparison of the methods revealed no significant diffennces in accuracy...

Accounting for differing exposure patterns between laboratory tests and the field in the assessment of long-term risks of pesticides to terrestrial vertebrates.

PubMed

Fischer, David L

2005-11-01

Long-term risks of pesticides to birds and mammals are currently assessed by comparing effects thresholds determined in chronic laboratory studies to exposure levels expected to occur in the field. However, there is often a mismatch between exposure patterns tested in the laboratory tests (exposure levels held constant) and those experienced by animals in the field (exposure levels varying over time). Three methods for addressing this problem are presented and discussed. Time-weighted averaging (TWA) converts a variable field exposure regime to a single value that can be compared directly to the laboratory test results. Body-burden modeling (BBM) is applied to both laboratory and field exposure regimes allowing a straightforward comparison of body residue levels expected for each situation. Temporal analysis (TA) uses expert judgment to decide if the length of time exposure exceeds a toxicity threshold is long enough to cause biologically significant effects. To reduce uncertainty in long-term assessments, the conduct of specialized laboratory tests in which test subjects are administered a time-varying exposure that mimics what occurs in the field should be considered. Such tests may also be useful testing the validity of each of these assessment methods.

Leaching behaviour of incineration bottom ash in a reuse scenario: 12years-field data vs. lab test results.

PubMed

Di Gianfilippo, Martina; Hyks, Jiri; Verginelli, Iason; Costa, Giulia; Hjelmar, Ole; Lombardi, Francesco

2018-03-01

Several types of standardized laboratory leaching tests have been developed during the past few decades to evaluate the leaching behaviour of waste materials as a function of different parameters, such as the pH of the eluate and the liquid to solid ratio. However, the link between the results of these tests and leaching data collected from the field (e.g. in disposal or reuse scenarios) is not always straightforward. In this work, we compare data obtained from an on-going large scale field trial, in which municipal solid waste incineration bottom ash is being tested as road sub-base material, with the results obtained from percolation column and pH-dependence laboratory leaching tests carried out on the bottom ash at the beginning of the test. The comparisons reported in this paper show that for soluble substances (e.g. Cl, K and SO 4 ), percolation column tests can provide a good indication of the release expected in the field with deviations usually within a factor of 3. For metals characterized by a solubility-controlled release, i.e. that depends more on eluate pH than the liquid to solid ratio applied, the results of pH-dependence tests describe more accurately the eluate concentration trends observed in the field with deviations that in most cases (around 80%) are within one order of magnitude (see e.g. Al and Cd). The differences between field and lab-scale data might be in part ascribed to the occurrence in the field of weathering reactions (e.g. carbonation) but also to microbial decomposition of organic matter that modifying leachate pH affect the solubility of several constituents (e.g. Ca, Ba and Cr). Besides, weathering reactions can result in enhanced adsorption of fulvic acids to iron/aluminum (hydr)oxides, leading to a decrease in the leaching of fulvic acids and hence of elements such as Cu, Ni and Pb that strongly depend on DOC leaching. Overall, this comparison shows that percolation column tests and pH-dependence tests can represent a reliable screening tool to derive data that could be employed in risk-based analysis or life cycle assessment (LCA) frameworks for evaluating potential environmental impacts deriving from specific disposal/reuse options for waste materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

A "TEST OF CONCEPT" COMPARISON OF AERODYNAMIC AND MECHANICAL RESUSPENSION MECHANISMS FOR PARTICLES DEPOSITED ON FIELD RYE GRASS (SECALE CERCELE). PART I. RELATIVE PARTICLE FLUX RATES

EPA Science Inventory

Resuspension of uniform latex micro spheres deposited on a single seed pod of field rye grass stalk and head was investigated experimentally in a wind tunnel. The experiment was designed to distinguish aerodynamic (viscous and turbulent) mechanisms from mechanical resuspension re...

Bilateral comparison on electric field measurements between TÜBİTAK UME and SASO NMCC

NASA Astrophysics Data System (ADS)

Aslan, Çağlar; Alrobaish, Abdullah M.; Şen, Osman

2017-01-01

Electromagnetic (EM) probes are widely utilized in the measurement of EM fields for non-ionizing radiation, electromagnetic compatibility (EMC) testing and other applications in the frequency range 5 Hz-60 GHz. They must be calibrated by National Metrology Institutes (NMIs) or accredited calibration laboratories in accordance with international standards such as IEEE 1309. The existing NMIs or emerging NMIs should refer to the international comparison measurements in order to assure the quality of their measurement results. Therefore, the electric field comparison measurements organized by TUBITAK UME were performed between TUBITAK UME and SASO NMCC at the 100 Hz, 1 kHz, 10 MHz, 100 MHz, 1 GHz, 10 GHz and 18 GHz frequencies in order to obtain the correction factors of the electric field probes. The comparison measurements were carried out in accordance with the Technical Protocol prepared by TUBITAK UME. The measurements started in October 2017 and were completed in January 2017. There was good agreement found for the correction factors. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Total-dose radiation effects data for semiconductor devices, volume 3

NASA Technical Reports Server (NTRS)

Price, W. E.; Martin, K. E.; Nichols, D. K.; Gauthier, M. K.; Brown, S. F.

1982-01-01

Volume 3 of this three-volume set provides a detailed analysis of the data in Volumes 1 and 2, most of which was generated for the Galileo Orbiter Program in support of NASA space programs. Volume 1 includes total ionizing dose radiation test data on diodes, bipolar transistors, field effect transistors, and miscellaneous discrete solid-state devices. Volume 2 includes similar data on integrated circuits and a few large-scale integrated circuits. The data of Volumes 1 and 2 are combined in graphic format in Volume 3 to provide a comparison of radiation sensitivities of devices of a given type and different manufacturer, a comparison of multiple tests for a single data code, a comparison of multiple tests for a single lot, and a comparison of radiation sensitivities vs time (date codes). All data were generated using a steady-state 2.5-MeV electron source (Dynamitron) or a Cobalt-60 gamma ray source. The data that compose Volume 3 represent 26 different device types, 224 tests, and a total of 1040 devices. A comparison of the effects of steady-state electrons and Cobat-60 gamma rays is also presented.

Investigation of outside visual cues required for low speed and hover

NASA Technical Reports Server (NTRS)

Hoh, R. H.

1985-01-01

Knowledge of the visual cues required in the performance of stabilized hover in VTOL aircraft is a prerequisite for the development of both cockpit displays and ground-based simulation systems. Attention is presently given to the viability of experimental test flight techniques as the bases for the identification of essential external cues in aggressive and precise low speed and hovering tasks. The analysis and flight test program conducted employed a helicopter and a pilot wearing lenses that could be electronically fogged, where the primary variables were field-of-view, large object 'macrotexture', and fine detail 'microtexture', in six different fields-of-view. Fundamental metrics are proposed for the quantification of the visual field, to allow comparisons between tests, simulations, and aircraft displays.

Comparison of RPR 'teardrop' card test, VDRL and FTA-ABS tests results on sera from persons with suspected yaws in Columbia.

PubMed

Hopkins, D R; Florez, D

1977-08-01

A small study comparing results of the rapid plasma reagin (RPR) teardrop card test performed in the field, with results of Venereal Disease Research Laboratory (VDRL) and fluorescent treponemal antibody absorption (FTA-ABS) tests performed in the laboratory on venous blood specimens from the same suspected yaws patients was undertaken in Columbia in July 1975. The results suggest that the RPR teardrop card test may be used to screen for infectious, or potentially infectious, yaws patients under field conditions, but that it will not reliably detect patients with VDRL titres of 1:2 or less, or all patients in whom sera are reactive in the FTA-ABS test.

Comparison of RPR 'teardrop' card test, VDRL and FTA-ABS tests results on sera from persons with suspected yaws in Columbia.

PubMed Central

Hopkins, D R; Florez, D

1977-01-01

A small study comparing results of the rapid plasma reagin (RPR) teardrop card test performed in the field, with results of Venereal Disease Research Laboratory (VDRL) and fluorescent treponemal antibody absorption (FTA-ABS) tests performed in the laboratory on venous blood specimens from the same suspected yaws patients was undertaken in Columbia in July 1975. The results suggest that the RPR teardrop card test may be used to screen for infectious, or potentially infectious, yaws patients under field conditions, but that it will not reliably detect patients with VDRL titres of 1:2 or less, or all patients in whom sera are reactive in the FTA-ABS test. PMID:336143

Structural Validity of the Movement ABC-2 Test: Factor Structure Comparisons across Three Age Groups

ERIC Educational Resources Information Center

Schulz, Joerg; Henderson, Sheila E.; Sugden, David A.; Barnett, Anna L.

2011-01-01

Background: The Movement ABC test is one of the most widely used assessments in the field of Developmental Coordination Disorder (DCD). Improvements to the 2nd edition of the test (M-ABC-2) include an extension of the age range and reduction in the number of age bands as well as revision of tasks. The total test score provides a measure of motor…

Optimal Bayesian Adaptive Design for Test-Item Calibration.

PubMed

van der Linden, Wim J; Ren, Hao

2015-06-01

An optimal adaptive design for test-item calibration based on Bayesian optimality criteria is presented. The design adapts the choice of field-test items to the examinees taking an operational adaptive test using both the information in the posterior distributions of their ability parameters and the current posterior distributions of the field-test parameters. Different criteria of optimality based on the two types of posterior distributions are possible. The design can be implemented using an MCMC scheme with alternating stages of sampling from the posterior distributions of the test takers' ability parameters and the parameters of the field-test items while reusing samples from earlier posterior distributions of the other parameters. Results from a simulation study demonstrated the feasibility of the proposed MCMC implementation for operational item calibration. A comparison of performances for different optimality criteria showed faster calibration of substantial numbers of items for the criterion of D-optimality relative to A-optimality, a special case of c-optimality, and random assignment of items to the test takers.

Environmental testing of terrestrial flat plate photovoltaic modules

NASA Technical Reports Server (NTRS)

Hoffman, A.; Griffith, J.

1979-01-01

The Low-Cost Solar Array (LSA) Project at the Jet Propulsion Laboratory has as one objective: the development and implementation of environmental tests for flat plate photovoltaic modules as part of the Department of Energy's terrestrial photovoltaic program. Modules procured under this program have been subjected to a variety of laboratory tests intended to simulate service environments, and the results of these tests have been compared to available data from actual field service. This comparison indicates that certain tests (notably temperature cycling, humidity cycling, and cyclic pressure loading) are effective indicators of some forms of field failures. Other tests have yielded results useful in formulating module design guidelines. Not all effects noted in field service have been successfully reproduced in the laboratory, however, and work is continuing in order to improve the value of the test program as a tool for evaluating module design and workmanship. This paper contains a review of these ongoing efforts and an assessment of significant test results to date.

Comparison between visual field defect in pigmentary glaucoma and primary open-angle glaucoma.

PubMed

Nilforushan, Naveed; Yadgari, Maryam; Jazayeri, Anisalsadat

2016-10-01

To compare visual field defect patterns between pigmentary glaucoma and primary open-angle glaucoma. Retrospective, comparative study. Patients with diagnosis of primary open-angle glaucoma (POAG) and pigmentary glaucoma (PG) in mild to moderate stages were enrolled in this study. Each of the 52 point locations in total and pattern deviation plot (excluding 2 points adjacent to blind spot) of 24-2 Humphrey visual field as well as six predetermined sectors were compared using SPSS software version 20. Comparisons between 2 groups were performed with the Student t test for continuous variables and the Chi-square test for categorical variables. Thirty-eight eyes of 24 patients with a mean age of 66.26 ± 11 years (range 48-81 years) in the POAG group and 36 eyes of 22 patients with a mean age of 50.52 ± 11 years (range 36-69 years) in the PG group were studied. (P = 0.00). More deviation was detected in points 1, 3, 4, and 32 in total deviation (P = 0.03, P = 0.015, P = 0.018, P = 0.023) and in points 3, 4, and 32 in pattern deviation (P = 0.015, P = 0.049, P = 0.030) in the POAG group, which are the temporal parts of the field. It seems that the temporal area of the visual field in primary open-angle glaucoma is more susceptible to damage in comparison with pigmentary glaucoma.

Comparison of Signal Response Between EDM Notch and Cracks in Eddy-Current Testing

NASA Technical Reports Server (NTRS)

Kane, Mary; Koshti, Ajay

2008-01-01

In the field of ET an eddy-current instrument is calibrated on a manufactured notch that is designed to simulate a defect in a part. The calibrated instrument is then used to scan parts with the assumption that any response that is over half the amplitude of the notch signal is taken to be defective. The purpose of this study is to attempt a direct comparison of the signal response observed from an EDM notch to a crack of the same size. To make this comparison test equipment will be set up and calibrated as per normal inspection procedures. Once this has been achieved both notches and as many different sizes of crack specimens will be scanned and the data recorded. This data will then be analyzed to provide a comparison of the response. The results should also provide information that shows it is acceptable to use the half-amplitude method for determining if a part is defective. The tests will be performed on two different materials commonly inspected, titanium and aluminum. This will allow a comparison of the results between materials.

Comparison of sampling and test methods for determining asphalt content and moisture correction in asphalt concrete mixtures.

DOT National Transportation Integrated Search

1985-03-01

The purpose of this report is to identify the difference, if any, in AASHTO and OSHD test procedures and results. This report addresses the effect of the size of samples taken in the field and evaluates the methods of determining the moisture content...

Emissions from Southeastern U.S. Grasslands and Pine Savannas: Comparison of Aerial and Ground Field Measurements with Laboratory Burns

EPA Science Inventory

Emissions from prescribed burns of forest and grass stands in western Florida were measured by simultaneous aerial and ground sampling. Results were compared with biomass gathered from the same stands and tested in an open burn laboratory test facility. Measurements included pol...

Grape Juice as an Attractant for Anastrepha suspensa (Diptera: Tephritidae) and Zaprionus indianus (Diptera: Drosophilidae)

USDA-ARS?s Scientific Manuscript database

In field tests conducted in south Florida to test grape juice as an alternative inexpensive bait for Anastrepha suspensa Loew, high numbers of Zaprionus indianus Gupta were captured in traps baited with aqueous grape juice. These experiments included comparisons of grape juice with standard A. susp...

Financial comparison of three testing strategies for detection of estrus in dairy cattle.

PubMed

Mohammed, H O; Loefler, S; Shearer, J

1990-03-15

Three commercial tests that measure progesterone content in milk were evaluated for accuracy of estrus detection. The tests were evaluated on 96 milk samples collected from Holstein cows at a commercial dairy farm in central Florida. The test results were compared with the results of radioimmunoassay on the same sample. Comparisons were made by calculating the sensitivities, specificities, and predictive values. The significance of the statistical association between the tests and the radioimmunoassay was evaluated by use of the McNemar chi 2 test. Decision-tree analysis was used to determine the most useful testing strategy, considering both cost and accuracy. The cowside progesterone assay on estrus-mount detector-positive cows was more profitable than use of estrus-mount patches alone. The return on investment was higher with the cowside test, making it preferred as a field test for detecting estrus.

Two laboratory methods for the calibration of GPS speed meters

NASA Astrophysics Data System (ADS)

Bai, Yin; Sun, Qiao; Du, Lei; Yu, Mei; Bai, Jie

2015-01-01

The set-ups of two calibration systems are presented to investigate calibration methods of GPS speed meters. The GPS speed meter calibrated is a special type of high accuracy speed meter for vehicles which uses Doppler demodulation of GPS signals to calculate the measured speed of a moving target. Three experiments are performed: including simulated calibration, field-test signal replay calibration, and in-field test comparison with an optical speed meter. The experiments are conducted at specific speeds in the range of 40-180 km h-1 with the same GPS speed meter as the device under calibration. The evaluation of measurement results validates both methods for calibrating GPS speed meters. The relative deviations between the measurement results of the GPS-based high accuracy speed meter and those of the optical speed meter are analyzed, and the equivalent uncertainty of the comparison is evaluated. The comparison results justify the utilization of GPS speed meters as reference equipment if no fewer than seven satellites are available. This study contributes to the widespread use of GPS-based high accuracy speed meters as legal reference equipment in traffic speed metrology.

Laser geodynamic satellite thermal/optical/vibrational analysis and testing, volume 2, book 2. [cubes and far fields

NASA Technical Reports Server (NTRS)

1975-01-01

The main tasks described involved an interferometric evaluation of several cubes, a prediction of their dihedral angles, a comparison of these predictions with independent measurements, a prediction and comparison of far field performance, recommendations as to revised dihedral angles and a subsequent analysis of cubes which were reworked to confirm the recommendations. A tolerance study and theoretical evaluation of several cubes was also performed to aid in understanding the results. The far field characteristics evaluated included polarization effects and treated both intensity distribution and encircled energy data. The energy in the 13.2 - 16.9 arc-sec annular region was tabulated as an indicator of performance sensitivity. The results are provided in viewgraph form, and show the average dihedral angle of an original set of test cubes to have been 1.8 arc-sec with an average far field annulus diameter of 18 arc-sec. Since the peak energy in the 13.2 - 16.9 arc-sec annulus was found to occur for a 1.35 arc-sec cube, and since cube tolerances were shown to increase the annulus diameter slightly, a nominal dihedral angle of 1.25 arc-sec was recommended.

A first look at lightning energy determined from GLM

NASA Astrophysics Data System (ADS)

Bitzer, P. M.; Burchfield, J. C.; Brunner, K. N.

2017-12-01

The Geostationary Lightning Mapper (GLM) was launched in November 2016 onboard GOES-16 has been undergoing post launch and product post launch testing. While these have typically focused on lightning metrics such as detection efficiency, false alarm rate, and location accuracy, there are other attributes of the lightning discharge that are provided by GLM data. Namely, the optical energy radiated by lightning may provide information useful for lightning physics and the relationship of lightning energy to severe weather development. This work presents initial estimates of the lightning optical energy detected by GLM during this initial testing, with a focus on observations during field campaign during spring 2017 in Huntsville. This region is advantageous for the comparison due to the proliferation of ground-based lightning instrumentation, including a lightning mapping array, interferometer, HAMMA (an array of electric field change meters), high speed video cameras, and several long range VLF networks. In addition, the field campaign included airborne observations of the optical emission and electric field changes. The initial estimates will be compared with previous observations using TRMM-LIS. In addition, a comparison between the operational and scientific GLM data sets will also be discussed.

Discussion of comparison study of hydraulic fracturing models -- Test case: GRI Staged Field Experiment No. 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cleary, M.P.

This paper provides comments to a companion journal paper on predictive modeling of hydraulic fracturing patterns (N.R. Warpinski et. al., 1994). The former paper was designed to compare various modeling methods to demonstrate the most accurate methods under various geologic constraints. The comments of this paper are centered around potential deficiencies in the former authors paper which include: limited actual comparisons offered between models, the issues of matching predictive data with that from related field operations was lacking or undocumented, and the relevance/impact of accurate modeling on the overall hydraulic fracturing cost and production.

Analysis of delamination related fracture processes in composites

NASA Technical Reports Server (NTRS)

Armanios, Erian A.

1992-01-01

An anisotropic thin walled closed section beam theory was developed based on an asymptotical analysis of the shell energy functional. The displacement field is not assumed a priori and emerges as a result of the analysis. In addition to the classical out-of-plane torsional warping, two new contributions are identified namely, axial strain and bending warping. A comparison of the derived governing equations confirms the theory developed by Reissner and Tsai. Also, explicit closed form expressions for the beam stiffness coefficients, the stress and displacement fields are provided. The predictions of the present theory were validated by comparison with finite element simulation, other closed form analyses and test data.

Assessment of models proposed for the 1985 revision of the international geomagnetic reference field

USGS Publications Warehouse

Peddie, N.W.; Zunde, A.K.

1987-01-01

Geomagnetic measurements from land, marine and aerial surveys conducted in the years 1945-1964 were used to test the 14 models proposed as additions, for that period, to the series of definitive geomagnetic reference field (DGRF) models. Overall, NASA's 'SFAS' models and the BGS (British Geological Survey) models agree best with these data. Comparisons of the two proposed definitive main-field models for 1980.0, with each other and with the existing IGRF 1980 main-field model, show mostly close agreement, with the greatest absolute differences (several tens of nanotesla) occurring in the region of Antarctica. Comparison of the the three proposed forecast secular-variation models for 1985-1990 with estimates of recent rates of change at 148 magnetic observatories shows that the IZMIRAN (U.S.S.R.) and USGS models are in closest agreement with these data. ?? 1987.

Density test study.

DOT National Transportation Integrated Search

1984-01-01

This report presents the results of an investigation of the comparison of percent density determinations between dry, 4 in. square sawed samples and 4 in. wet cores measured in both the field and the lab. Recommendations are given concerning the rela...

Measurement and prediction of propeller flow field on the PTA aircraft at speeds of up to Mach 0.85. [Propfan Test Assessment

NASA Technical Reports Server (NTRS)

Aljabri, Abdullah S.

1988-01-01

High speed subsonic transports powered by advanced propellers provide significant fuel savings compared to turbofan powered transports. Unfortunately, however, propfans must operate in aircraft-induced nonuniform flow fields which can lead to high blade cyclic stresses, vibration and noise. To optimize the design and installation of these advanced propellers, therefore, detailed knowledge of the complex flow field is required. As part of the NASA Propfan Test Assessment (PTA) program, a 1/9 scale semispan model of the Gulfstream II propfan test-bed aircraft was tested in the NASA-Lewis 8 x 6 supersonic wind tunnel to obtain propeller flow field data. Detailed radial and azimuthal surveys were made to obtain the total pressure in the flow and the three components of velocity. Data was acquired for Mach numbers ranging from 0.6 to 0.85. Analytical predictions were also made using a subsonic panel method, QUADPAN. Comparison of wind-tunnel measurements and analytical predictions show good agreement throughout the Mach range.

Homemade thermometry instruments in the field.

PubMed

Pasquier, Mathieu; Rousson, Valentin; Zen Ruffinen, Grégoire; Hugli, Olivier

2012-03-01

Esophageal temperature is the gold standard for in-the-field temperature monitoring in hypothermic victims with cardiac arrest. For practical reasons, some mountain rescue teams use homemade esophageal thermometers to measure esophageal temperature; these consist of nonmedical inside/outside temperature monitoring instruments that have been modified to allow for esophageal insertion. We planned a study to determine the accuracy of such thermometers. Two of the same model of digital cabled indoor/outdoor thermometer were modified and tested in comparison with a reference thermometer. The thermometers were tested in a water bath at different temperatures between 10°C and 35.2°C. Three hundred measurements were taken with each thermometer. Our experimental study showed that both homemade thermometers provided a good correlation and a clinically acceptable agreement in comparison with the reference thermometer. Measurements were within 0.5°C in comparison with the reference thermometer 97.5% of the time. The homemade thermometers performed well in vitro, in comparison with a reference thermometer. However, because these devices in their original form are not designed for clinical use, their use should be restricted to situations when the use of a conventional esophageal thermometer is impossible. Copyright © 2012 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Spacecraft Communications System Verification Using On-Axis Near Field Measurement Techniques

NASA Technical Reports Server (NTRS)

Keating, Thomas; Baugh, Mark; Gosselin, R. B.; Lecha, Maria C.; Krebs, Carolyn A. (Technical Monitor)

2000-01-01

Determination of the readiness of a spacecraft for launch is a critical requirement. The final assembly of all subsystems must be verified. Testing of a communications system can mostly be done using closed-circuits (cabling to/from test ports), but the final connections to the antenna require radiation tests. The Tropical Rainfall Measuring Mission (TRMM) Project used a readily available 'near-fleld on-axis' equation to predict the values to be used for comparison with those obtained in a test program. Tests were performed in a 'clean room' environment at both Goddard Space Flight Center (GSFC) and in Japan at the Tanegashima Space Center (TnSC) launch facilities. Most of the measured values agreed with the predicted values to within 0.5 dB. This demonstrates that sometimes you can use relatively simple techniques to make antenna performance measurements when use of the 'far field ranges, anechoic chambers, or precision near-field ranges' are neither available nor practical. Test data and photographs are provided.

An objective comparison of commercially-available cavitation meters.

PubMed

Sarno, Daniel; Hodnett, Mark; Wang, Lian; Zeqiri, Bajram

2017-01-01

With a number of cavitation meters on the market which claim to characterise fields in ultrasonic cleaning baths, this paper provides an objective comparison of a selection of these devices and establishes the extent to which their claims are met. The National Physical Laboratory's multi-frequency ultrasonic reference vessel provided the stable 21.06kHz field, above and below the inertial cavitation threshold, as a test bed for the sensor comparison. Measurements from these devices were evaluated in relation to the known acoustic pressure distribution in the cavitating vessel as a means of identifying the mode of operation of the sensors and to examine the particular indicator of cavitation activity which they deliver. Through the comparison with megahertz filtered acoustic signals generated by inertial cavitation, it was determined that the majority of the cavitation meters used in this study responded to acoustic pressure generated by the direct applied acoustic field and therefore tended to overestimate the occurrence of cavitation within the vessel, giving non-zero responses under conditions when there was known to be no inertial cavitation occurring with the reference vessel. This has implications for interpreting the data they provide in user applications. Copyright © 2016. Published by Elsevier B.V.

Comparison of Different Measurement Technologies for the In-Flight Assessment of Radiated Acoustic Intensity

NASA Technical Reports Server (NTRS)

Klos, Jacob; Palumbo, Daniel L.; Buehrle, Ralph D.; Williams, Earl G.; Valdivia, Nicolas; Herdic, Peter C.; Sklanka, Bernard

2005-01-01

A series of tests was planned and conducted in the Interior Noise Test Facility at Boeing Field, on the NASA Aries 757 flight research aircraft, and in the Structural Acoustic Loads and Transmission Facility at NASA Langley Research Center. These tests were designed to answer several questions concerning the use of array methods in flight. One focus of the tests was determining whether and to what extent array methods could be used to identify the effects of an acoustical treatment applied to a limited portion of an aircraft fuselage. Another focus of the tests was to verify that the arrays could be used to localize and quantify a known source purposely placed in front of the arrays. Thus the issues related to backside sources and flanking paths present in the complicated sound field were addressed during these tests. These issues were addressed through the use of reference transducers, both accelerometers mounted to the fuselage and microphones in the cabin, that were used to correlate the pressure holograms. measured by the microphone arrays using either SVD methods or partial coherence methods. This correlation analysis accepts only energy that is coherent with the sources sensed by the reference transducers, allowing a noise control engineer to only identify and study those vibratory sources of interest. The remainder of this paper will present a detailed description of the test setups that were used in this test sequence and typical results of the NAH/IBEM analysis used to reconstruct the sound fields. Also, a comparison of data obtained in the laboratory environments and during flights of the 757 aircraft will be made.

Comparison of methods for in vitro testing of susceptibility of porcine Mycoplasma species to antimicrobial agents.

PubMed

Ter Laak, E A; Pijpers, A; Noordergraaf, J H; Schoevers, E C; Verheijden, J H

1991-02-01

The MICs of 18 antimicrobial agents used against strains of three porcine Mycoplasma species were determined by a serial broth dilution method. Twenty field strains of M. hyorhinis, ten field strains of M. hyopneumoniae, six field strains of M. flocculare, and the type strains of these species were tested. Twelve field strains and the type strain of M. hyorhinis were also tested by an agar dilution method. Tests were read at various time points. When the broth dilution method was used, the final MIC had to be read 2 days after color changes had stopped. MICs of tetracycline, oxytetracycline, doxycycline, and minocycline were low for the three Mycoplasma species tested. MICs of chlortetracycline were 8 to 16 times higher than MICs of the other tetracyclines. Spiramycin, tylosin, kitasamycin, spectinomycin, tiamulin, lincomycin, and clindamycin were effective against all strains of M. hyorhinis and M. hyopneumoniae. The quinolones were highly effective against M. hyopneumoniae but less effective against M. hyorhinis. The susceptibility patterns for M. hyopneumoniae and M. flocculare were similar.

Comparison of methods for in vitro testing of susceptibility of porcine Mycoplasma species to antimicrobial agents.

PubMed Central

Ter Laak, E A; Pijpers, A; Noordergraaf, J H; Schoevers, E C; Verheijden, J H

1991-01-01

The MICs of 18 antimicrobial agents used against strains of three porcine Mycoplasma species were determined by a serial broth dilution method. Twenty field strains of M. hyorhinis, ten field strains of M. hyopneumoniae, six field strains of M. flocculare, and the type strains of these species were tested. Twelve field strains and the type strain of M. hyorhinis were also tested by an agar dilution method. Tests were read at various time points. When the broth dilution method was used, the final MIC had to be read 2 days after color changes had stopped. MICs of tetracycline, oxytetracycline, doxycycline, and minocycline were low for the three Mycoplasma species tested. MICs of chlortetracycline were 8 to 16 times higher than MICs of the other tetracyclines. Spiramycin, tylosin, kitasamycin, spectinomycin, tiamulin, lincomycin, and clindamycin were effective against all strains of M. hyorhinis and M. hyopneumoniae. The quinolones were highly effective against M. hyopneumoniae but less effective against M. hyorhinis. The susceptibility patterns for M. hyopneumoniae and M. flocculare were similar. PMID:2024954

Comparison of Cellulose Iβ Simulations with Three Carbohydrate Force Fields.

PubMed

Matthews, James F; Beckham, Gregg T; Bergenstråhle-Wohlert, Malin; Brady, John W; Himmel, Michael E; Crowley, Michael F

2012-02-14

Molecular dynamics simulations of cellulose have recently become more prevalent due to increased interest in renewable energy applications, and many atomistic and coarse-grained force fields exist that can be applied to cellulose. However, to date no systematic comparison between carbohydrate force fields has been conducted for this important system. To that end, we present a molecular dynamics simulation study of hydrated, 36-chain cellulose Iβ microfibrils at room temperature with three carbohydrate force fields (CHARMM35, GLYCAM06, and Gromos 45a4) up to the near-microsecond time scale. Our results indicate that each of these simulated microfibrils diverge from the cellulose Iβ crystal structure to varying degrees under the conditions tested. The CHARMM35 and GLYCAM06 force fields eventually result in structures similar to those observed at 500 K with the same force fields, which are consistent with the experimentally observed high-temperature behavior of cellulose I. The third force field, Gromos 45a4, produces behavior significantly different from experiment, from the other two force fields, and from previously reported simulations with this force field using shorter simulation times and constrained periodic boundary conditions. For the GLYCAM06 force field, initial hydrogen-bond conformations and choice of electrostatic scaling factors significantly affect the rate of structural divergence. Our results suggest dramatically different time scales for convergence of properties of interest, which is important in the design of computational studies and comparisons to experimental data. This study highlights that further experimental and theoretical work is required to understand the structure of small diameter cellulose microfibrils typical of plant cellulose.

Visual field defects after missile injuries to the geniculo-striate pathway in man.

NASA Technical Reports Server (NTRS)

Koerner, F.; Teuber, H.-L.

1973-01-01

The main objective of the survey reported was a quantitative comparison of different visual functions at identical retinal points of individual patients. The possibility to develop objective forms of visual-field testing was also explored, taking into account reports by Frydrychowicz and Harms (1940) and Harms (1951). These investigators had insisted that pupillary responses to light are depressed in areas of homonymous scotomata. The shapes of homonymous visual field defects are discussed together with questions regarding the association and dissociation of symptoms.

Effect of zero magnetic field on cardiovascular system and microcirculation

NASA Astrophysics Data System (ADS)

Gurfinkel, Yu. I.; At'kov, O. Yu.; Vasin, A. L.; Breus, T. K.; Sasonko, M. L.; Pishchalnikov, R. Yu.

2016-02-01

The effects of zero magnetic field conditions on cardiovascular system of healthy adults have been studied. In order to generate zero magnetic field, the facility for magnetic fields modeling ;ARFA; has been used. Parameters of the capillary blood flow, blood pressure, and the electrocardiogram (ECG) monitoring were measured during the study. All subjects were tested twice: in zero magnetic field and, for comparison, in sham condition. The obtained results during 60 minutes of zero magnetic field exposure demonstrate a clear effect on cardiovascular system and microcirculation. The results of our experiments can be used in studies of long-term stay in hypo-magnetic conditions during interplanetary missions.

Field measurements of the linear and nonlinear shear moduli of cemented alluvium using dynamically loaded surface footings

NASA Astrophysics Data System (ADS)

Park, Kwangsoo

In this dissertation, a research effort aimed at development and implementation of a direct field test method to evaluate the linear and nonlinear shear modulus of soil is presented. The field method utilizes a surface footing that is dynamically loaded horizontally. The test procedure involves applying static and dynamic loads to the surface footing and measuring the soil response beneath the loaded area using embedded geophones. A wide range in dynamic loads under a constant static load permits measurements of linear and nonlinear shear wave propagation from which shear moduli and associated shearing strains are evaluated. Shear wave velocities in the linear and nonlinear strain ranges are calculated from time delays in waveforms monitored by geophone pairs. Shear moduli are then obtained using the shear wave velocities and the mass density of a soil. Shear strains are determined using particle displacements calculated from particle velocities measured at the geophones by assuming a linear variation between geophone pairs. The field test method was validated by conducting an initial field experiment at sandy site in Austin, Texas. Then, field experiments were performed on cemented alluvium, a complex, hard-to-sample material. Three separate locations at Yucca Mountain, Nevada were tested. The tests successfully measured: (1) the effect of confining pressure on shear and compression moduli in the linear strain range and (2) the effect of strain on shear moduli at various states of stress in the field. The field measurements were first compared with empirical relationships for uncemented gravel. This comparison showed that the alluvium was clearly cemented. The field measurements were then compared to other independent measurements including laboratory resonant column tests and field seismic tests using the spectral-analysis-of-surface-waves method. The results from the field tests were generally in good agreement with the other independent test results, indicating that the proposed method has the ability to directly evaluate complex material like cemented alluvium in the field.

Turkish Teachers' and Students' Perceptions towards Computer Assisted Testing in Comparison with Spanish Teachers' and Students' Perceptions

ERIC Educational Resources Information Center

Berber, Aslihan; García Laborda, Jesús

2015-01-01

There are different opinions about using technology in the assessment field of education regarding computer-assisted assessments. People have some concerns such as its application, reliability and so on. It seems that those concerns may decrease with the developing technology in the following years since computer-based testing programs are…

Field significance of performance measures in the context of regional climate model evaluation. Part 2: precipitation

NASA Astrophysics Data System (ADS)

Ivanov, Martin; Warrach-Sagi, Kirsten; Wulfmeyer, Volker

2018-04-01

A new approach for rigorous spatial analysis of the downscaling performance of regional climate model (RCM) simulations is introduced. It is based on a multiple comparison of the local tests at the grid cells and is also known as `field' or `global' significance. The block length for the local resampling tests is precisely determined to adequately account for the time series structure. New performance measures for estimating the added value of downscaled data relative to the large-scale forcing fields are developed. The methodology is exemplarily applied to a standard EURO-CORDEX hindcast simulation with the Weather Research and Forecasting (WRF) model coupled with the land surface model NOAH at 0.11 ∘ grid resolution. Daily precipitation climatology for the 1990-2009 period is analysed for Germany for winter and summer in comparison with high-resolution gridded observations from the German Weather Service. The field significance test controls the proportion of falsely rejected local tests in a meaningful way and is robust to spatial dependence. Hence, the spatial patterns of the statistically significant local tests are also meaningful. We interpret them from a process-oriented perspective. While the downscaled precipitation distributions are statistically indistinguishable from the observed ones in most regions in summer, the biases of some distribution characteristics are significant over large areas in winter. WRF-NOAH generates appropriate stationary fine-scale climate features in the daily precipitation field over regions of complex topography in both seasons and appropriate transient fine-scale features almost everywhere in summer. As the added value of global climate model (GCM)-driven simulations cannot be smaller than this perfect-boundary estimate, this work demonstrates in a rigorous manner the clear additional value of dynamical downscaling over global climate simulations. The evaluation methodology has a broad spectrum of applicability as it is distribution-free, robust to spatial dependence, and accounts for time series structure.

Six-month Longitudinal Comparison of a Portable Tablet Perimeter With the Humphrey Field Analyzer.

PubMed

Prea, Selwyn Marc; Kong, Yu Xiang George; Mehta, Aditi; He, Mingguang; Crowston, Jonathan G; Gupta, Vinay; Martin, Keith R; Vingrys, Algis J

2018-06-01

To establish the medium-term repeatability of the iPad perimetry app Melbourne Rapid Fields (MRF) compared to Humphrey Field Analyzer (HFA) 24-2 SITA-standard and SITA-fast programs. Multicenter longitudinal observational clinical study. Sixty patients (stable glaucoma/ocular hypertension/glaucoma suspects) were recruited into a 6-month longitudinal clinical study with visits planned at baseline and at 2, 4, and 6 months. At each visit patients undertook visual field assessment using the MRF perimetry application and either HFA SITA-fast (n = 21) or SITA-standard (n = 39). The primary outcome measure was the association and repeatability of mean deviation (MD) for the MRF and HFA tests. Secondary measures were the point-wise threshold and repeatability for each test, as well as test time. MRF was similar to SITA-fast in speed and significantly faster than SITA-standard (MRF 4.6 ± 0.1 minutes vs SITA-fast 4.3 ± 0.2 minutes vs SITA-standard 6.2 ± 0.1 minutes, P < .001). Intraclass correlation coefficients (ICC) between MRF and SITA-fast for MD at the 4 visits ranged from 0.71 to 0.88. ICC values between MRF and SITA-standard for MD ranged from 0.81 to 0.90. Repeatability of MRF MD outcomes was excellent, with ICC for baseline and the 6-month visit being 0.98 (95% confidence interval: 0.96-0.99). In comparison, ICC at 6-month retest for SITA-fast was 0.95 and SITA-standard 0.93. Fewer points changed with the MRF, although for those that did, the MRF gave greater point-wise variability than did the SITA tests. MRF correlated strongly with HFA across 4 visits over a 6-month period, and has good test-retest reliability. MRF is suitable for monitoring visual fields in settings where conventional perimetry is not readily accessible. Copyright © 2018 Elsevier Inc. All rights reserved.

Radar stage uncertainty

USGS Publications Warehouse

Fulford, J.M.; Davies, W.J.

2005-01-01

The U.S. Geological Survey is investigating the performance of radars used for stage (or water-level) measurement. This paper presents a comparison of estimated uncertainties and data for radar water-level measurements with float, bubbler, and wire weight water-level measurements. The radar sensor was also temperature-tested in a laboratory. The uncertainty estimates indicate that radar measurements are more accurate than uncorrected pressure sensors at higher water stages, but are less accurate than pressure sensors at low stages. Field data at two sites indicate that radar sensors may have a small negative bias. Comparison of field radar measurements with wire weight measurements found that the radar tends to measure slightly lower values as stage increases. Copyright ASCE 2005.

Three dimensional viscous analysis of a hypersonic inlet

NASA Technical Reports Server (NTRS)

Reddy, D. R.; Smith, G. E.; Liou, M.-F.; Benson, Thomas J.

1989-01-01

The flow fields in supersonic/hypersonic inlets are currently being studied at NASA Lewis Research Center using 2- and 3-D full Navier-Stokes and Parabolized Navier-Stokes solvers. These tools have been used to analyze the flow through the McDonnell Douglas Option 2 inlet which has been tested at Calspan in support of the National Aerospace Plane Program. Comparisons between the computational and experimental results are presented. These comparisons lead to better overall understanding of the complex flows present in this class of inlets. The aspects of the flow field emphasized in this work are the 3-D effects, the transition from laminar to turbulent flow, and the strong nonuniformities generated within the inlet.

Support vector machines-based modelling of seismic liquefaction potential

NASA Astrophysics Data System (ADS)

Pal, Mahesh

2006-08-01

This paper investigates the potential of support vector machines (SVM)-based classification approach to assess the liquefaction potential from actual standard penetration test (SPT) and cone penetration test (CPT) field data. SVMs are based on statistical learning theory and found to work well in comparison to neural networks in several other applications. Both CPT and SPT field data sets is used with SVMs for predicting the occurrence and non-occurrence of liquefaction based on different input parameter combination. With SPT and CPT test data sets, highest accuracy of 96 and 97%, respectively, was achieved with SVMs. This suggests that SVMs can effectively be used to model the complex relationship between different soil parameter and the liquefaction potential. Several other combinations of input variable were used to assess the influence of different input parameters on liquefaction potential. Proposed approach suggest that neither normalized cone resistance value with CPT data nor the calculation of standardized SPT value is required with SPT data. Further, SVMs required few user-defined parameters and provide better performance in comparison to neural network approach.

Isolation, identification and field tests of the sex pheromone of the carambola fruit borer, Eucosma notanthes.

PubMed

Hung, C C; Hwang, J S; Hung, M D; Yen, Y P; Hou, R F

2001-09-01

Two components, (Z)-8-dodecenyl acetate (Z8-12:Ac) and (Z)-8-dodecenol (Z8-12:OH), were isolated from sex pheromone glands of the carambola fruit borer, Eucosma notanthes, and were identified by GC, and GC-MS, chemical derivatization, and comparison of retention times. The ratio of the alcohol to acetate in the sex pheromone extracts was 2.7. However, synthetic mixtures (1 mg) in ratios ranging from 0.5 to 1.5 were more effective than other blends in trapping male moths in field tests.

Suited for Space

NASA Technical Reports Server (NTRS)

Kosmo, Joseph J.

2006-01-01

This viewgraph presentation describes the basic functions of space suits for EVA astronauts. Space suits are also described from the past, present and future space missions. The contents include: 1) Why Do You Need A Space Suit?; 2) Generic EVA System Requirements; 3) Apollo Lunar Surface Cycling Certification; 4) EVA Operating Cycles for Mars Surface Missions; 5) Mars Surface EVA Mission Cycle Requirements; 6) Robustness Durability Requirements Comparison; 7) Carry-Weight Capabilities; 8) EVA System Challenges (Mars); 9) Human Planetary Surface Exploration Experience; 10) NASA Johnson Space Center Planetary Analog Activities; 11) Why Perform Remote Field Tests; and 12) Other Reasons Why We Perform Remote Field Tests.

Planar near-field scanning for compact range bistatic radar cross-section measurement. Thesis Final Report

NASA Technical Reports Server (NTRS)

Tuhela-Reuning, S. R.; Walton, E. K.

1991-01-01

The design, construction, and testing of a low cost, planar scanning system to be used in a compact range environment for bistatic radar cross-section (bistatic RCS) measurement data are discussed. This scanning system is similar to structures used for measuring near-field antenna patterns. A synthetic aperture technique is used for plane wave reception. System testing entailed comparison of measured and theoretical bistatic RCS of a sphere and a right circular cylinder. Bistatic scattering analysis of the ogival target support, target and pedestal interactions, and compact range room was necessary to determine measurement validity.

The prediction of rotor rotational noise using measured fluctuating blade loads

NASA Technical Reports Server (NTRS)

Hosier, R. N.; Pegg, R. J.; Ramakrishnan, R.

1974-01-01

In tests conducted at the NASA Langley Research Center Helicopter Rotor Test Facility, simultaneous measurements of the high-frequency fluctuating aerodynamic blade loads and far-field radiated noise were made on a full-scale, nontranslating rotor system. After their characteristics were determined, the measured blade loads were used in an existing theory to predict the far-field rotational noise. A comparison of the calculated and measured rotational noise is presented with specific attention given to the effect of blade loading coefficients, chordwise loading distributions, blade loading phases, and observer azimuthal position on the predictions.

[Evaluation of acoustic effectiveness of personnel protectors from extra-aural exposure to aviation noise].

PubMed

Dragan, S P; Soldatov, S K; Bogomolov, A V; Drozdov, S V; Poliakov, N M

2013-01-01

Purpose of the investigation was to validate testing acoustic effectiveness of a personnel vest-like protector (PP) from extra-aural exposure to aviation noise. Levels of aviation noise for PP testing were determined through calculation. Vest effectiveness in protecting from acoustic vibration generated by high-intensity aviation noise was evaluated both in laboratory and field tests. For comparison analysis, PP was also tested with a dummy exposed on a special tester, i.e. acoustic interferometer.

Blunt-Body Aerothermodynamic Database from High-Enthalpy CO2 Testing in an Expansion Tunnel

NASA Technical Reports Server (NTRS)

Hollis, Brian R.; Prabhu, Dinesh K.; Maclean, Matthew; Dufrene, Aaron

2016-01-01

An extensive database of heating, pressure, and flow field measurements on a 70-deg sphere-cone blunt body geometry in high-enthalpy, CO2 flow has been generated through testing in an expansion tunnel. This database is intended to support development and validation of computational tools and methods to be employed in the design of future Mars missions. The test was conducted in an expansion tunnel in order to avoid uncertainties in the definition of free stream conditions noted in previous studies performed in reflected shock tunnels. Data were obtained across a wide range of test velocity/density conditions that produced various physical phenomena of interest, including laminar and transitional/turbulent boundary layers, non-reacting to completely dissociated post-shock gas composition and shock-layer radiation. Flow field computations were performed at the test conditions and comparisons were made with the experimental data. Based on these comparisons, it is recommended that computational uncertainties on surface heating and pressure, for laminar, reacting-gas environments can be reduced to +/-10% and +/-5%, respectively. However, for flows with turbulence and shock-layer radiation, there were not sufficient validation-quality data obtained in this study to make any conclusions with respect to uncertainties, which highlights the need for further research in these areas.

Application of line-scanning microscopy using a linear sensor in semiconductor industry: shape and thickness measurements

NASA Astrophysics Data System (ADS)

Macedo, Milton P.; Correia, C. M. B. A.

2013-04-01

This work aims at showing the applicability of a scanning-stage bench-microscope in bright-field reflection mode for wirebonding inspection of integrated circuits (IC) as well as quality assurance of tracks in printed circuit boards (PCB). The main issues of our laboratorial prototype arise from the use of a linear image sensor taking advantage of its geometry to achieve lower acquisition time in comparison to traditional (pinhole) confocal approach. The use of a slit-detector is normally related to resolution degradation for details parallel to sensor. But an improvement will surely arise using light distribution along line pixels of the sensor which establishes a great advantage in comparison to (pure) slit detectors. The versatility of this bench-microscope affords excellent means to develop and test algorithms. Those to improve lateral resolution isotropy as well as image visualization and 3D mesh reconstruction under different setups namely illumination modes. Based on the results of these tests tests both wide-field illumination and parallel slit illumination and detection configurations were used in these two applications. Results from IC wire-bonding show the ability of the system to extract 3D information. A comparison of auto-focus images and 3D profiles obtained using different 3D reconstruction algorithms as well as a method for the determination of the diameter of the bond wire are presented. Measurements of PCB track width and thickness were performed and the comparison of these results from both longitudinal and transverse tracks stress the limitations of a lower spatial sampling rate induced by the resolution of object stage positioners.

Acoustical characteristics of the NASA Langley full scale wind tunnel test section

NASA Technical Reports Server (NTRS)

Abrahamson, A. L.; Kasper, P. K.; Pappa, R. S.

1975-01-01

The full-scale wind tunnel at NASA-Langley Research Center was designed for low-speed aerodynamic testing of aircraft. Sound absorbing treatment has been added to the ceiling and walls of the tunnel test section to create a more anechoic condition for taking acoustical measurements during aerodynamic tests. The results of an experimental investigation of the present acoustical characteristics of the tunnel test section are presented. The experimental program included measurements of ambient nosie levels existing during various tunnel operating conditions, investigation of the sound field produced by an omnidirectional source, and determination of sound field decay rates for impulsive noise excitation. A comparison of the current results with previous measurements shows that the added sound treatment has improved the acoustical condition of the tunnel test section. An analysis of the data indicate that sound reflections from the tunnel ground-board platform could create difficulties in the interpretation of actual test results.

A comparison of semiautomated versus manual Goldmann kinetic perimetry in patients with visually significant glaucoma.

PubMed

Ramirez, Adriana M; Chaya, Craig J; Gordon, Lynn K; Giaconi, Joann A

2008-03-01

To determine if semiautomated kinetic perimetry (SKP) is reproducible and comparable to Goldmann manual kinetic perimetry (GVF). Glaucoma patients were recruited to perform visual field testing using GVF and SKP. Specific isopters were tested, quantified, and compared. Visual field patterns were analyzed for shape and defect. Ten patients (16 eyes) underwent visual field studies using SKP and GVF, and 8 patients completed a second SKP on a different day. Individual isopter areas were similar between GVF and SKP, although 60% of isopters were larger on SKP by an average of 15%. This was statistically significant for the smaller isopters, I4e (P=0.02) and I2e (P=0.05). Retesting with SKP on a separate day, showed similar isopter areas (P values=0.3 to 1.0), however, the exact location of isopters in degrees from central fixation tended to vary with the smaller test object sizes. Isopter position in degrees from the central axis agreed in at least 3 quadrants in approximately 65% of fields compared. SKP visual field defects and patterns were similar between test strategies. SKP and GVF testing produce similar visual field results in glaucoma patients, and SKP testing seems to be reliable and reproducible in this population. However, overlapping isopters, typically associated with nonorganic vision loss, and jagged isopters were sometimes observed in SKP visual fields. Further study of SKP is needed to explore these findings.

An interlaboratory comparison programme on radio frequency electromagnetic field measurements: the second round of the scheme.

PubMed

Nicolopoulou, E P; Ztoupis, I N; Karabetsos, E; Gonos, I F; Stathopulos, I A

2015-04-01

The second round of an interlaboratory comparison scheme on radio frequency electromagnetic field measurements has been conducted in order to evaluate the overall performance of laboratories that perform measurements in the vicinity of mobile phone base stations and broadcast antenna facilities. The participants recorded the electric field strength produced by two high frequency signal generators inside an anechoic chamber in three measurement scenarios with the antennas transmitting each time different signals at the FM, VHF, UHF and GSM frequency bands. In each measurement scenario, the participants also used their measurements in order to calculate the relative exposure ratios. The results were evaluated in each test level calculating performance statistics (z-scores and En numbers). Subsequently, possible sources of errors for each participating laboratory were discussed, and the overall evaluation of their performances was determined by using an aggregated performance statistic. A comparison between the two rounds proves the necessity of the scheme. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Interlaboratory Comparison of Quantitative PCR Test Results for Dehalococcoides

EPA Science Inventory

Quantitative PCR (qPCR) techniques have been widely used to measure Dehalococcoides (Dhc) DNA in the groundwater at field sites for several years. Interpretation of these data may be complicated when different laboratories using alternate methods conduct the analysis. An...

Comparison of a degree-day computer and a recording thermograph in a forest environment.

Treesearch

Boyd E. Wickman

1985-01-01

A field test showed that degree-days accumulated by a miniature computer and a recording thermograph in early spring and summer were comparable. For phenological studies the biophenometer was as accurate and more efficient than the hygrothermograph.

Comparison of aircraft noise measured in flight test and in the NASA Ames 40- by 80-foot wind tunnel.

NASA Technical Reports Server (NTRS)

Atencio, A., Jr.; Soderman, P. T.

1973-01-01

A method to determine free-field aircraft noise spectra from wind-tunnel measurements has been developed. The crux of the method is the correction for reverberations. Calibrated loud speakers are used to simulate model sound sources in the wind tunnel. Corrections based on the difference between the direct and reverberant field levels are applied to wind-tunnel data for a wide range of aircraft noise sources. To establish the validity of the correction method, two research aircraft - one propeller-driven (YOV-10A) and one turbojet-powered (XV-5B) - were flown in free field and then tested in the wind tunnel. Corrected noise spectra from the two environments agree closely.

A comparison of cation sampling in forest soils by tension and tension-free lysimeters

Treesearch

James H. Miller

1981-01-01

Field tests conducted in two soils with ceramic cup, ceramic plate, and tension-free lysimeters showed no concentration differences in collected cations (Ca, Mg, K, Na) between cups and plates, except for the hydrogen ion. Mean pH was 0.6 lower in cup collected samples for a sandy loam profile. Tension-free lysimeters of the design tested had persistent contamination...

CSTT Update: Fuel Quality Analyzer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brosha, Eric L.; Lujan, Roger W.; Mukundan, Rangachary

These are slides from a presentation. The following topics are covered: project background (scope and approach), developing the prototype (timeline), update on intellectual property, analyzer comparisons (improving humidification, stabilizing the baseline, applying clean-up strategy, impact of ionomer content and improving clean-up), proposed operating mode, considerations for testing in real-world conditions (Gen 1 analyzer electronics development, testing partner identified, field trial planning), summary, and future work.

Optical fiber reliability results from the Biarritz field trial

NASA Astrophysics Data System (ADS)

Gouronnec, Alain; Goarin, Rolland; Le Moigne, G.; Baptiste, M.

1994-09-01

The first experimental optical fiber network (fiber to the home CATV and video-phone) was installed in BIARRITZ, France) at the beginning or 1980. Some parts of the first optical links have now been removed. FRANCE TELECOM decided to stop field trial services, it appeared interesting to evaluate and expertise fiber reliability after more than 10 years of aging in a real adverse field environment. In this paper we give a short description of the layed down links, and indicate how we have carefully removed the individual fibers from the cables. After a first measurement of the mechanical parameters using normalized dynamic and static tests, we compared the results obtained with those of the equivalent tests used to evaluate these fibers before their installation on the field. The tests used are the same than those used in the 80 th. In conclusion, the paper gives the ageing results measured on the BIARRITZ optical fibers after more than 10 years of service in real environment and evaluate it by comparison with the results before installation.

Broad frequency band full field measurements for advanced applications: Point-wise comparisons between optical technologies

NASA Astrophysics Data System (ADS)

Zanarini, Alessandro

2018-01-01

The progress of optical systems gives nowadays at disposal on lightweight structures complex dynamic measurements and modal tests, each with its own advantages, drawbacks and preferred usage domains. It is thus more easy than before to obtain highly spatially defined vibration patterns for many applications in vibration engineering, testing and general product development. The potential of three completely different technologies is here benchmarked on a common test rig and advanced applications. SLDV, dynamic ESPI and hi-speed DIC are here first deployed in a complex and unique test on the estimation of FRFs with high spatial accuracy from a thin vibrating plate. The latter exhibits a broad band dynamics and high modal density in the common frequency domain where the techniques can find an operative intersection. A peculiar point-wise comparison is here addressed by means of discrete geometry transforms to put all the three technologies on trial at each physical point of the surface. Full field measurement technologies cannot estimate only displacement fields on a refined grid, but can exploit the spatial consistency of the results through neighbouring locations by means of numerical differentiation operators in the spatial domain to obtain rotational degrees of freedom and superficial dynamic strain distributions, with enhanced quality, compared to other technologies in literature. Approaching the task with the aid of superior quality receptance maps from the three different full field gears, this work calculates and compares rotational and dynamic strain FRFs. Dynamic stress FRFs can be modelled directly from the latter, by means of a constitutive model, avoiding the costly and time-consuming steps of building and tuning a numerical dynamic model of a flexible component or a structure in real life conditions. Once dynamic stress FRFs are obtained, spectral fatigue approaches can try to predict the life of a component in many excitation conditions. Different spectral shaping of the excitation can easily be used to enhance the comparison in the framework of any of the spectral approaches for fatigue life calculations, highlighting benefits and drawbacks of a direct experimental approach to failure and risk assessment in structural dynamics when dealing with complex patterns in real-life testing. Are optical measurements and spatially dense datasets really effective in advanced model updating of lightweight structures with complex structural dynamics? The noise shown in the raw signal of some experiments may pose issues in proficiently exploiting the added data in a fruitful model updating procedure. Model updating results are here compared between scanning and native full field technologies, with comments and details on the test rig, on the advantages and drawbacks of the approaches. The identification of EMA models highlights the increasing quality of shapes that can be obtained from native full field high resolution gears, against that (some time unexpectedly poor) of SLDV tested.

Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

NASA Technical Reports Server (NTRS)

Gong, Qian; Content, David; Dominguez, Margaret; Emmett, Thomas; Griesmann, Ulf; Hagopian, John; Kruk, Jeffrey; Marx, Catherine; Pasquale, Bert; Wallace, Thomas;

Aerobic power and field test results of amateur 15-a-side rugby union players.

PubMed

Sant'anna, Ricardo T; de Souza Castro, Flávio A

2017-12-01

The aim of the present study was to verify whether it is possible to predict aerobic power in amateur 15-a-side rugby union players through the Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IRT1) and the 5-meter Multiple Shuttle Test (5-m MST). Forty-two amateur players - 22 forwards and 20 backs - were evaluated in three phases: 1) maximum treadmill test in the laboratory; 2) field test set by a drawing in the first phase; and 3) second field test. Descriptive, comparison, correlation, regression and level of agreement analyses were performed. Backs, when compared to forwards, showed a higher VO2max (61.7±15 mL/kg/min and 51.6±10.1 mL/kg/min, respectively), Yo-Yo IRT1 final level (16.4±0.8 and 14.9±0.9, respectively) and Yo-Yo IRT1 total distance (1283.3±312.5 m and 792±277.6 m, respectively), and a higher final distance in the 5-m MST (686.8±36.6 and 642.9±46.5, respectively). Significant correlations were found between the result and the total distance on the Yo-Yo IRT1 and the VO2max (r=0.425 and r=0.459, respectively). Using the total distance covered in the Yo-Yo IRT1, the VO2max of amateur 15-a-side rugby union players can be estimated through the equation VO2max = 0.016 × (DIST Yo‑Yo) + 40.578. Yo-Yo IRT1 is most useful when the objective is to evaluate the aerobic power of amateur RU players in comparison with the 5-m MST.

Asset Analysis and Operational Concepts for Separation Assurance Flight Testing at Dryden Flight Research Center

NASA Technical Reports Server (NTRS)

Costa, Guillermo J.; Arteaga, Ricardo A.

2011-01-01

A preliminary survey of existing separation assurance and collision avoidance advancements, technologies, and efforts has been conducted in order to develop a concept of operations for flight testing autonomous separation assurance at Dryden Flight Research Center. This effort was part of the Unmanned Aerial Systems in the National Airspace System project. The survey focused primarily on separation assurance projects validated through flight testing (including lessons learned), however current forays into the field were also examined. Comparisons between current Dryden flight and range assets were conducted using House of Quality matrices in order to allow project management to make determinations regarding asset utilization for future flight tests. This was conducted in order to establish a body of knowledge of the current collision avoidance landscape, and thus focus Dryden s efforts more effectively towards the providing of assets and test ranges for future flight testing within this research field.

PV systems photoelectric parameters determining for field conditions and real operation conditions

NASA Astrophysics Data System (ADS)

Shepovalova, Olga V.

2018-05-01

In this work, research experience and reference documentation have been generalized related to PV systems photoelectric parameters (PV array output parameters) determining. The basic method has been presented that makes it possible to determine photoelectric parameters with the state-of-the-art reliability and repeatability. This method provides an effective tool for PV systems comparison and evaluation of PV system parameters that the end-user will have in the course of its real operation for compliance with those stipulated in reference documentation. The method takes in consideration all parameters that may possibly affect photoelectric performance and that are supported by sufficiently valid procedures for their values testing. Test conditions, requirements for equipment subject to tests and test preparations have been established and the test procedure for fully equipped PV system in field tests and in real operation conditions has been described.

CFD Simulations of the IHF Arc-Jet Flow: Compression-Pad/Separation Bolt Wedge Tests

NASA Technical Reports Server (NTRS)

Gokcen, Tahir; Skokova, Kristina A.

2017-01-01

This paper reports computational analyses in support of two wedge tests in a high enthalpy arc-jet facility at NASA Ames Research Center. These tests were conducted using two different wedge models, each placed in a free jet downstream of a corresponding different conical nozzle in the Ames 60-MW Interaction Heating Facility. Panel test articles included a metallic separation bolt imbedded in the compression-pad and heat shield materials, resulting in a circular protuberance over a flat plate. As part of the test calibration runs, surface pressure and heat flux measurements on water-cooled calibration plates integrated with the wedge models were also obtained. Surface heating distributions on the test articles as well as arc-jet test environment parameters for each test configuration are obtained through computational fluid dynamics simulations, consistent with the facility and calibration measurements. The present analysis comprises simulations of the non-equilibrium flow field in the facility nozzle, test box, and flow field over test articles, and comparisons with the measured calibration data.

Covariance and Quantum Cosmology: A Comparison of Two Matter Clocks

NASA Astrophysics Data System (ADS)

Halnon, Theodore; Bojowald, Martin

2017-01-01

In relativity, time is relative between reference frames. However, quantum mechanics requires a specific time coordinate in order to write an evolution equation for wave functions. This difference between the two theories leads to the problem of time in quantum gravity. One method to study quantum relativity is to interpret the dynamics of a matter field as a clock. In order to test the relationship between different reference frames, an isotropic cosmological model with two matter ingredients is introduced. One is given by a scalar field and one by vacuum energy or a cosmological constant. There are two matter fields, and thus two different Hamiltonians are derived from the respective clock rates. Semi-classical solutions are found for these equations and a comparison is made of the physical predictions that they imply. Partial funding from the Ronald E. McNair Postbaccalaureate Achievement Program.

Systematic Validation of Protein Force Fields against Experimental Data

PubMed Central

Eastwood, Michael P.; Dror, Ron O.; Shaw, David E.

2012-01-01

Molecular dynamics simulations provide a vehicle for capturing the structures, motions, and interactions of biological macromolecules in full atomic detail. The accuracy of such simulations, however, is critically dependent on the force field—the mathematical model used to approximate the atomic-level forces acting on the simulated molecular system. Here we present a systematic and extensive evaluation of eight different protein force fields based on comparisons of experimental data with molecular dynamics simulations that reach a previously inaccessible timescale. First, through extensive comparisons with experimental NMR data, we examined the force fields' abilities to describe the structure and fluctuations of folded proteins. Second, we quantified potential biases towards different secondary structure types by comparing experimental and simulation data for small peptides that preferentially populate either helical or sheet-like structures. Third, we tested the force fields' abilities to fold two small proteins—one α-helical, the other with β-sheet structure. The results suggest that force fields have improved over time, and that the most recent versions, while not perfect, provide an accurate description of many structural and dynamical properties of proteins. PMID:22384157

The Gumbel hypothesis test for left censored observations using regional earthquake records as an example

NASA Astrophysics Data System (ADS)

Thompson, E. M.; Hewlett, J. B.; Baise, L. G.; Vogel, R. M.

2011-01-01

Annual maximum (AM) time series are incomplete (i.e., censored) when no events are included above the assumed censoring threshold (i.e., magnitude of completeness). We introduce a distrtibutional hypothesis test for left-censored Gumbel observations based on the probability plot correlation coefficient (PPCC). Critical values of the PPCC hypothesis test statistic are computed from Monte-Carlo simulations and are a function of sample size, censoring level, and significance level. When applied to a global catalog of earthquake observations, the left-censored Gumbel PPCC tests are unable to reject the Gumbel hypothesis for 45 of 46 seismic regions. We apply four different field significance tests for combining individual tests into a collective hypothesis test. None of the field significance tests are able to reject the global hypothesis that AM earthquake magnitudes arise from a Gumbel distribution. Because the field significance levels are not conclusive, we also compute the likelihood that these field significance tests are unable to reject the Gumbel model when the samples arise from a more complex distributional alternative. A power study documents that the censored Gumbel PPCC test is unable to reject some important and viable Generalized Extreme Value (GEV) alternatives. Thus, we cannot rule out the possibility that the global AM earthquake time series could arise from a GEV distribution with a finite upper bound, also known as a reverse Weibull distribution. Our power study also indicates that the binomial and uniform field significance tests are substantially more powerful than the more commonly used Bonferonni and false discovery rate multiple comparison procedures.

Multisampling suprathreshold perimetry: a comparison with conventional suprathreshold and full-threshold strategies by computer simulation.

PubMed

Artes, Paul H; Henson, David B; Harper, Robert; McLeod, David

2003-06-01

To compare a multisampling suprathreshold strategy with conventional suprathreshold and full-threshold strategies in detecting localized visual field defects and in quantifying the area of loss. Probability theory was applied to examine various suprathreshold pass criteria (i.e., the number of stimuli that have to be seen for a test location to be classified as normal). A suprathreshold strategy that requires three seen or three missed stimuli per test location (multisampling suprathreshold) was selected for further investigation. Simulation was used to determine how the multisampling suprathreshold, conventional suprathreshold, and full-threshold strategies detect localized field loss. To determine the systematic error and variability in estimates of loss area, artificial fields were generated with clustered defects (0-25 field locations with 8- and 16-dB loss) and, for each condition, the number of test locations classified as defective (suprathreshold strategies) and with pattern deviation probability less than 5% (full-threshold strategy), was derived from 1000 simulated test results. The full-threshold and multisampling suprathreshold strategies had similar sensitivity to field loss. Both detected defects earlier than the conventional suprathreshold strategy. The pattern deviation probability analyses of full-threshold results underestimated the area of field loss. The conventional suprathreshold perimetry also underestimated the defect area. With multisampling suprathreshold perimetry, the estimates of defect area were less variable and exhibited lower systematic error. Multisampling suprathreshold paradigms may be a powerful alternative to other strategies of visual field testing. Clinical trials are needed to verify these findings.

Mars Rover Navigation Results Using Sun Sensor Heading Determination

NASA Technical Reports Server (NTRS)

Volpe, Richard

1998-01-01

Upcoming missions to the surface of Mars will use mobile robots to traverse long distances from the landing site. To prepare for these missions, the prototype rover, Rocky 7, has been tested in desert field trials conducted with a team of planetary scientists. While several new capabilities have been demonstrated, foremost among these was sun-sensor based traversal of natural terrain totaling a distance of one kilometer. This paper describes navigation results obtained in the field tests, where cross-track error was only 6% of distance traveled. Comparison with previous results of other planetary rover systems shows this to be a significant improvement.

Comparison of A-SMGCS Requirements with Observed Performance of an Integrated Airport CNS System

NASA Technical Reports Server (NTRS)

Young, Steven D.

1997-01-01

The International Civil Aviation Organization (ICAO) has recently drafted a reference document describing the operational requirements for Advanced Surface Movement Guidance and Control Systems (A-SMGCS). During the summer of 1997, NASA, the FAA, industry, and academia partners demonstrated a holistic system approach that has the potential to meet many of the proposed A-SMGCS requirements. An assessment of the field tested system and data resulting from the field testing is presented to determine its compliance with A-SMGCS requirements. In those areas where compliance was not demonstrated, a recommendation is presented suggesting further research or a modification of the system architecture.

FIELD MEASUREMENTS OF CONTAMINANT FLUX BY INTEGRAL PUMPING TESTS (SAN FRANCISCO, CA)

EPA Science Inventory

Current remedial techniques are unable to completely eliminate all dense nonaqueous phase liquid (DNAPL) from source zone areas and conflicting views on the benefits of partial DNAPL source zone remediation exist in the literature. A comparison of flux measurements before and af...

Comparison of Controlled Field Test Aerosol Generation Devices to a Laboratory Device

DTIC Science & Technology

2013-11-01

detector, and it allows airflow through the region between its exhaust tube and the detector inlet tube. 2 The atomizer (Aerogen; Dangan, Galway ...Aerogen; Dangan, Galway , Ireland. http://www.aerogen.com/ aeroneb-go.html (accessed October 2013). Byron, P. Dosing Reproducibility from Experimental

Comparison of hemagglutination inhibition test and ELISA in quantification of antibodies to egg drop syndrome virus.

PubMed

Raj, G Dhinakar; Ratnapraba, S; Matheswaran, K; Nachimuthu, K

2004-01-01

A single-serum dilution ELISA for egg drop syndrome (EDS) virus-specific antibodies was developed. In testing 425 chicken sera it was found to have a 93.6% sensitivity and 98.7% specificity relative to a hemagglutination inhibition (HI) test. The correlation coefficient for ELISA and HI titers was 0.793. The ELISA was efficacious in quantification of both vaccinal and infection antibodies and could routinely be used for screening large numbers of field sera.

Comparison of Threshold Saccadic Vector Optokinetic Perimetry (SVOP) and Standard Automated Perimetry (SAP) in Glaucoma. Part II: Patterns of Visual Field Loss and Acceptability.

PubMed

McTrusty, Alice D; Cameron, Lorraine A; Perperidis, Antonios; Brash, Harry M; Tatham, Andrew J; Agarwal, Pankaj K; Murray, Ian C; Fleck, Brian W; Minns, Robert A

2017-09-01

We compared patterns of visual field loss detected by standard automated perimetry (SAP) to saccadic vector optokinetic perimetry (SVOP) and examined patient perceptions of each test. A cross-sectional study was done of 58 healthy subjects and 103 with glaucoma who were tested using SAP and two versions of SVOP (v1 and v2). Visual fields from both devices were categorized by masked graders as: 0, normal; 1, paracentral defect; 2, nasal step; 3, arcuate defect; 4, altitudinal; 5, biarcuate; and 6, end-stage field loss. SVOP and SAP classifications were cross-tabulated. Subjects completed a questionnaire on their opinions of each test. We analyzed 142 (v1) and 111 (v2) SVOP and SAP test pairs. SVOP v2 had a sensitivity of 97.7% and specificity of 77.9% for identifying normal versus abnormal visual fields. SAP and SVOP v2 classifications showed complete agreement in 54% of glaucoma patients, with a further 23% disagreeing by one category. On repeat testing, 86% of SVOP v2 classifications agreed with the previous test, compared to 91% of SAP classifications; 71% of subjects preferred SVOP compared to 20% who preferred SAP. Eye-tracking perimetry can be used to obtain threshold visual field sensitivity values in patients with glaucoma and produce maps of visual field defects, with patterns exhibiting close agreement to SAP. Patients preferred eye-tracking perimetry compared to SAP. This first report of threshold eye tracking perimetry shows good agreement with conventional automated perimetry and provides a benchmark for future iterations.

Microstructure-Based Computational Modeling of Mechanical Behavior of Polymer Micro/Nano Composites

DTIC Science & Technology

2013-12-01

K. ......... 165  Fig. 5.11. Comparison between experimental data and calibrated numerical models for displacement control tests, at three different...displacement control simulation) for all mesh densities for both work-conjugate and non work-conjugate. ........................ 302  Fig. 9.3. Damage...some large deformation experimental tests (and also accepting the non -uniformity of the strain field). In the established well-known theorem for

Radioactive waste disposal in the marine environment

NASA Astrophysics Data System (ADS)

Anderson, D. R.

In order to find the optimal solution to waste disposal problems, it is necessary to make comparisons between disposal media. It has become obvious to many within the scientific community that the single medium approach leads to over protection of one medium at the expense of the others. Cross media comparisons are being conducted in the Department of Energy ocean disposal programs for several radioactive wastes. Investigations in three areas address model development, comparisons of laboratory tests with field results and predictions, and research needs in marine disposal of radioactive waste. Tabulated data are included on composition of liquid high level waste and concentration of some natural radionuclides in the sea.

Anxiety in visual field testing.

PubMed

Chew, Shenton S L; Kerr, Nathan M; Wong, Aaron B C; Craig, Jennifer P; Chou, Chi-Ying; Danesh-Meyer, Helen V

2016-08-01

To determine if Humphrey visual field (HVF) testing induces anxiety and how anxiety relates to visual field parameters of reliability and severity. A prospective cohort study at a university affiliated private ophthalmic practice. 137 consecutive age-matched and gender-matched patients with glaucoma undergoing either HVF testing only (n=102) or Heidelberg retinal tomography (HRT) only (n=35) were enrolled. Prior to testing, participants completed the State-Trait Anxiety Inventory questionnaire. A 5-point Likert scale was used to grade pretest anxiety and was repeated after testing to grade intratest anxiety. Subjective discomfort parameters were also recorded. Anxiety scores were used to make non-parametrical comparisons and correlations between cohorts and also against visual field reliability and severity indices. Trait anxiety (p=0.838) and pretest anxiety (p=0.802) were not significantly different between test groups. Within the HVF group, intratest anxiety was 1.2 times higher than pretest anxiety (p=0.0001), but was not significantly different in the HRT group (p=0.145). Pretest anxiety was correlated with test unreliability (Spearman's r=0.273, p=0.006), which was predictive of worse test severity (p=0.0027). Subjects who had undergone more than 10 visual field tests had significantly lower pretest and intratest anxiety levels than those who had not (p=0.0030 and p=0.0004, respectively). HVF testing induces more anxiety than HRT. Increased pretest anxiety may reduce HVF test reliability. Increased test experience or interventions aimed at reducing pretest anxiety may result in improved test reliability and accuracy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Influence of the magnetic field profile on ITER conductor testing

NASA Astrophysics Data System (ADS)

Nijhuis, A.; Ilyin, Y.; ten Kate, H. H. J.

2006-08-01

We performed simulations with the numerical CUDI-CICC code on a typical short ITER (International Thermonuclear Experimental Reactor) conductor test sample of dual leg configuration, as usually tested in the SULTAN test facility, and made a comparison with the new EFDA-Dipole test facility offering a larger applied DC field region. The new EFDA-Dipole test facility, designed for short sample testing of conductors for ITER, has a homogeneous high field region of 1.2 m, while in the SULTAN facility this region is three times shorter. The inevitable non-uniformity of the current distribution in the cable, introduced by the joints at both ends, has a degrading effect on voltage-current (VI) and voltage-temperature (VT) characteristics, particularly for these short samples. This can easily result in an underestimation or overestimation of the actual conductor performance. A longer applied DC high field region along a conductor suppresses the current non-uniformity by increasing the overall longitudinal cable electric field when reaching the current sharing mode. The numerical interpretation study presented here gives a quantitative analysis for a relevant practical case of a test of a short sample poloidal field coil insert (PFCI) conductor in SULTAN. The simulation includes the results of current distribution analysis from self-field measurements with Hall sensor arrays, current sharing measurements and inter-petal resistance measurements. The outcome of the simulations confirms that the current uniformity improves with a longer high field region but the 'measured' VI transition is barely affected, though the local peak voltages become somewhat suppressed. It appears that the location of the high field region and voltage taps has practically no influence on the VI curve as long as the transverse voltage components are adequately cancelled. In particular, for a thin conduit wall, the voltage taps should be connected to the conduit in the form of an (open) azimuthally soldered wire, averaging the transverse conduit surface potentials initiated in the joints.

Shuttle Return-to-Flight IH-108 Aerothermal Test at CUBRC - Flow Field Calibration and CFD

NASA Technical Reports Server (NTRS)

Lau, Kei Y.; Holden, M. S.

2011-01-01

This paper discusses one specific aspect of the Shuttle Retrun-To-Flight IH-108 Aerothermal Test at Calspan-University of Buffalo Research Center (CUBRC), the test flow field calibration. It showed the versatility of the CUBRC Large Energy National Shock Tunnel (LENS) II wind tunnel for an aerothermal test with unique and demanding requirements. CFD analyses were used effectively to extend the test range at the low end of the Mach range. It demonstrated how ground test facility and CFD synergy can be utilitzed iteratively to enhance the confidence in the fedility of both tools. It addressed the lingering concerns of the aerothermal community on use of inpulse facility and CFD analysis. At the conclusion of the test program, members from the NASA Marshall (MSFC), CUBRC and USA (United Space Alliance) Consultants (The Grey Beards) were asked to independently verify the flight scaling data generated by Boeing for flight certification of the re-designed external tank (ET) components. The blind test comparison showed very good results.

Enabling reliability assessments of pre-commercial perovskite photovoltaics with lessons learned from industrial standards

NASA Astrophysics Data System (ADS)

Snaith, Henry J.; Hacke, Peter

2018-06-01

Photovoltaic modules are expected to operate in the field for more than 25 years, so reliability assessment is critical for the commercialization of new photovoltaic technologies. In early development stages, understanding and addressing the device degradation mechanisms are the priorities. However, any technology targeting large-scale deployment must eventually pass industry-standard qualification tests and undergo reliability testing to validate the module lifetime. In this Perspective, we review the methodologies used to assess the reliability of established photovoltaics technologies and to develop standardized qualification tests. We present the stress factors and stress levels for degradation mechanisms currently identified in pre-commercial perovskite devices, along with engineering concepts for mitigation of those degradation modes. Recommendations for complete and transparent reporting of stability tests are given, to facilitate future inter-laboratory comparisons and to further the understanding of field-relevant degradation mechanisms, which will benefit the development of accelerated stress tests.

Assessing five field sampling methods to monitor Yellowstone National Park's northern ungulate winter range: the advantages and disadvantages of implementing a new sampling protocol

Treesearch

Pamela G. Sikkink; Roy Renkin; Geneva Chong; Art Sikkink

2013-01-01

The five field sampling methods tested for this study differed in richness and Simpson's Index values calculated from the raw data. How much the methods differed, and which ones were most similar to each other, depended on which diversity measure and which type of data were used for comparisons. When the number of species (richness) was used as a measure of...

Comparison of the Performance of Noise Metrics as Predictions of the Annoyance of Stage 2 and Stage 3 Aircraft Overflights

NASA Technical Reports Server (NTRS)

Pearsons, Karl S.; Howe, Richard R.; Sneddon, Matthew D.; Fidell, Sanford

1996-01-01

Thirty audiometrically screened test participants judged the relative annoyance of two comparison (variable level) and thirty-four standard (fixed level) signals in an adaptive paired comparison psychoacoustic study. The signal ensemble included both FAR Part 36 Stage 2 and 3 aircraft overflights, as well as synthesized aircraft noise signatures and other non-aircraft signals. All test signals were presented for judgment as heard indoors, in the presence of continuous background noise, under free-field listening conditions in an anechoic chamber. Analyses of the performance of 30 noise metrics as predictors of these annoyance judgments confirmed that the more complex metrics were generally more accurate and precise predictors than the simpler methods. EPNL was somewhat less accurate and precise as a predictor of the annoyance judgments than a duration-adjusted variant of Zwicker's Loudness Level.

Comparison of geochemical data obtained using four brine sampling methods at the SECARB Phase III Anthropogenic Test CO2 injection site, Citronelle Oil Field, Alabama

USGS Publications Warehouse

Conaway, Christopher; Thordsen, James J.; Manning, Michael A.; Cook, Paul J.; Trautz, Robert C.; Thomas, Burt; Kharaka, Yousif K.

2016-01-01

The chemical composition of formation water and associated gases from the lower Cretaceous Paluxy Formation was determined using four different sampling methods at a characterization well in the Citronelle Oil Field, Alabama, as part of the Southeast Regional Carbon Sequestration Partnership (SECARB) Phase III Anthropogenic Test, which is an integrated carbon capture and storage project. In this study, formation water and gas samples were obtained from well D-9-8 #2 at Citronelle using gas lift, electric submersible pump, U-tube, and a downhole vacuum sampler (VS) and subjected to both field and laboratory analyses. Field chemical analyses included electrical conductivity, dissolved sulfide concentration, alkalinity, and pH; laboratory analyses included major, minor and trace elements, dissolved carbon, volatile fatty acids, free and dissolved gas species. The formation water obtained from this well is a Na–Ca–Cl-type brine with a salinity of about 200,000 mg/L total dissolved solids. Differences were evident between sampling methodologies, particularly in pH, Fe and alkalinity. There was little gas in samples, and gas composition results were strongly influenced by sampling methods. The results of the comparison demonstrate the difficulty and importance of preserving volatile analytes in samples, with the VS and U-tube system performing most favorably in this aspect.

Comparison of Matrix Frequency-Doubling Technology (FDT) Perimetry with the SWEDISH Interactive Thresholding Algorithm (SITA) Standard Automated Perimetry (SAP) in Mild Glaucoma.

PubMed

Doozandeh, Azadeh; Irandoost, Farnoosh; Mirzajani, Ali; Yazdani, Shahin; Pakravan, Mohammad; Esfandiari, Hamed

2017-01-01

This study aimed to compare second-generation frequency-doubling technology (FDT) perimetry with standard automated perimetry (SAP) in mild glaucoma. Forty-seven eyes of 47 participants who had mild visual field defect by SAP were included in this study. All participants were examined using SITA 24-2 (SITA-SAP) and matrix 24-2 (Matrix-FDT). The correlations of global indices and the number of defects on pattern deviation (PD) plots were determined. Agreement between two sets regarding the stage of visual field damage was assessed. Pearson's correlation, intra-cluster comparison, paired t-test, and 95% limit of agreement were calculated. Although there was no significant difference between global indices, the agreement between the two devices regarding the global indices was weak (the limit of agreement for mean deviation was -6.08 to 6.08 and that for pattern standard deviation was -4.42 to 3.42). The agreement between SITA-SAP and Matrix-FDT regarding the Glaucoma Hemifield Test (GHT) and the number of defective points in each quadrant and staging of the visual field damage was also weak. Because the correlation between SITA-SAP and Matrix-FDT regarding global indices, GHT, number of defective points, and stage of the visual field damage in mild glaucoma is weak, Matrix-FDT cannot be used interchangeably with SITA-SAP in the early stages of glaucoma.

[Comparative Analysis of Behavior in The Open-field Test in Wild Grey Rats (Rattus norvegicus) and in Grey Rats Subjected to Prolonged Selection for Tame And Aggressive Behavior].

PubMed

Kozhemyakina, R V; Konoshenko, M Yu; Sakharov, D G; Smagin, D A; Markel, A L

2016-01-01

The aim of this work is analysis of the open-field behavior in grey rats selected for the tame and aggressive behavior in comparison with the wild grey rats. Significant influences of the rat group factor on the 13 of 19 behavioral features studied in the open-field were found. This effect, in general, depends on existence of great differences between behaviors of the wild rats from the one hand and behaviors of the tame and aggressive rats from the other. The behaviors of the rats from the last two groups are practically identical. Multidimensional analysis confirms the distinct separation in coordinates of the two main components of the wild rat behavior from the behavior of both the tame and selectively bred aggressive rats. The first main component dimension corresponds to the grade of fear, which was significantly enhanced in the wild rats. So, in spite of the equality of behavioral aggressiveness of the wild rats and the rats selected for aggression with the glove test, the behavior of selected aggressive rats in the open-field is analogous to behavior of the rats selected for tameness. Comparison of behavioral features with the hormonal stress responsiveness allowed us to conclude that the aggressive behavior of the wild and se lected for aggression rats based on different motivational and neuroendocrine processes.

Comparison of visual field test results obtained through Humphrey matrix frequency doubling technology perimetry versus standard automated perimetry in healthy children.

PubMed

Kocabeyoglu, Sibel; Uzun, Salih; Mocan, Mehmet Cem; Bozkurt, Banu; Irkec, Murat; Orhan, Mehmet

2013-10-01

The aim of this study was to compare the visual field test results in healthy children obtained via the Humphrey matrix 24-2 threshold program and standard automated perimetry (SAP) using the Swedish interactive threshold algorithm (SITA)-Standard 24-2 test. This prospective study included 55 healthy children without ocular or systemic disorders who underwent both SAP and frequency doubling technology (FDT) perimetry visual field testing. Visual field test reliability indices, test duration, global indices (mean deviation [MD], and pattern standard deviation [PSD]) were compared between the 2 tests using the Wilcoxon signed-rank test and paired t-test. The performance of the Humphrey field analyzer (HFA) 24-2 SITA-standard and frequency-doubling technology Matrix 24-2 tests between genders were compared with Mann-Whitney U-test. Fifty-five healthy children with a mean age of 12.2 ± 1.9 years (range from 8 years to 16 years) were included in this prospective study. The test durations of SAP and FDT were similar (5.2 ± 0.5 and 5.1 ± 0.2 min, respectively, P = 0.651). MD and the PSD values obtained via FDT Matrix were significantly higher than those obtained via SAP (P < 0.001), and fixation losses and false negative errors were significantly less with SAP (P < 0.05). A weak positive correlation between the two tests in terms of MD (r = 0.352, P = 0.008) and PSD (r = 0.329, P = 0.014) was observed. Children were able to complete both the visual test algorithms successfully within 6 min. However, SAP testing appears to be associated with less depression of the visual field indices of healthy children. FDT Matrix and SAP should not be used interchangeably in the follow-up of children.

Improving Preschoolers' Mathematics Achievement with Tablets: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Schacter, John; Jo, Booil

2017-01-01

With a randomized field experiment of 433 preschoolers, we tested a tablet mathematics program designed to increase young children's mathematics learning. Intervention students played Math Shelf, a comprehensive iPad preschool and year 1 mathematics app, while comparison children received research-based hands-on mathematics instruction delivered…

Incidental Testicular Irradiation From Prostate IMRT: It All Adds Up

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, Christopher R., E-mail: crking@stanford.ed; Maxim, Peter G.; Hsu, Annie

Purpose: To identify the technical aspects of image-guided intensity-modulated radiation therapy (IMRT) for localized prostate cancer that could result in a clinically meaningful incidental dose to the testes. Methods and Materials: We examined three sources that contribute incidental dose to the testes, namely, from internal photon scattering from IMRT small field and large pelvic nodal fields with 6 or 15 MV, from neutrons when >10-MV photons are used, and from daily image-guided fiducial-based portal imaging. Using clinical data from 10 patients who received IMRT for prostate cancer, and thermo-luminescent dosimeter measurements in phantom, we estimated the dose to the testesmore » from each of these sources. Results: A mean testicular dose of 172 and 220 cGy results from internal photon scatter for pelvic nodal fields and 68 and 93 cGy for prostate-only fields, for 6- and 15-MV energies, respectively. For 15-MV photon energies, the mean testicular dose from neutrons is 60 cGy for pelvic fields and 31 cGy for prostate-only fields. From daily portal MV image guidance, the testes-in-field mean dose is 350 cGy, whereas the testes-out-of-field scatter dose is 16 cGy. Dosimetric comparisons between IMRT using 6-MV and 15-MV photon energies are not significantly different. Worst-case scenarios can potentially deliver cumulative incidental mean testicular doses of 630 cGy, whereas best-case scenarios can deliver only 84 cGy. Conclusions: Incidental dose to the testes from prostate IMRT can be minimized by opting to restrict the use of elective pelvic nodal fields, by choosing photon energies <10 MV, and by using the smallest port sizes necessary for daily image guidance.« less

Benchmarking the Performance of Mobile Laser Scanning Systems Using a Permanent Test Field

PubMed Central

Kaartinen, Harri; Hyyppä, Juha; Kukko, Antero; Jaakkola, Anttoni; Hyyppä, Hannu

2012-01-01

The performance of various mobile laser scanning systems was tested on an established urban test field. The test was connected to the European Spatial Data Research (EuroSDR) project “Mobile Mapping—Road Environment Mapping Using Mobile Laser Scanning”. Several commercial and research systems collected laser point cloud data on the same test field. The system comparisons focused on planimetric and elevation errors using a filtered digital elevation model, poles, and building corners as the reference objects. The results revealed the high quality of the point clouds generated by all of the tested systems under good GNSS conditions. With all professional systems properly calibrated, the elevation accuracy was better than 3.5 cm up to a range of 35 m. The best system achieved a planimetric accuracy of 2.5 cm over a range of 45 m. The planimetric errors increased as a function of range, but moderately so if the system was properly calibrated. The main focus on mobile laser scanning development in the near future should be on the improvement of the trajectory solution, especially under non-ideal conditions, using both improvements in hardware and software. Test fields are relatively easy to implement in built environments and they are feasible for verifying and comparing the performance of different systems and also for improving system calibration to achieve optimum quality.

Comparison of the analytical capabilities of the BAC Datamaster and Datamaster DMT forensic breath testing devices.

PubMed

Glinn, Michele; Adatsi, Felix; Curtis, Perry

2011-11-01

The State of Michigan uses the Datamaster as an evidential breath testing device. The newest version, the DMT, will replace current instruments in the field as they are retired from service. The Michigan State Police conducted comparison studies to test the analytical properties of the new instrument and to evaluate its response to conditions commonly cited in court defenses. The effects of mouth alcohol, objects in the mouth, and radiofrequency interference on paired samples from drinking subjects were assessed on the DMT. The effects of sample duration and chemical interferents were assessed on both instruments, using drinking subjects and wet-bath simulators, respectively. Our testing shows that Datamaster and DMT results are essentially identical; the DMT gave accurate readings as compared with measurements made using simulators containing standard ethanol solutions and that the DMT did not give falsely elevated breath alcohol results from any of the influences tested. © 2011 American Academy of Forensic Sciences.

FIMic: design for ultimate 3D-integral microscopy of in-vivo biological samples

PubMed Central

Scrofani, G.; Sola-Pikabea, J.; Llavador, A.; Sanchez-Ortiga, E.; Barreiro, J. C.; Saavedra, G.; Garcia-Sucerquia, J.; Martínez-Corral, M.

2017-01-01

In this work, Fourier integral microscope (FIMic), an ultimate design of 3D-integral microscopy, is presented. By placing a multiplexing microlens array at the aperture stop of the microscope objective of the host microscope, FIMic shows extended depth of field and enhanced lateral resolution in comparison with regular integral microscopy. As FIMic directly produces a set of orthographic views of the 3D-micrometer-sized sample, it is suitable for real-time imaging. Following regular integral-imaging reconstruction algorithms, a 2.75-fold enhanced depth of field and 2-time better spatial resolution in comparison with conventional integral microscopy is reported. Our claims are supported by theoretical analysis and experimental images of a resolution test target, cotton fibers, and in-vivo 3D-imaging of biological specimens. PMID:29359107

Fastener Recess Evaluation

DTIC Science & Technology

1978-04-01

lbs respectively. The Torx recess suffered most under the test methods adopted (as would any similar recess such as the internal hex). Zero values ...Administrationi, National Tool Center Apex Machine and Tool Co. r~. Phillips International Co.] Hi-Shear Corp. General Dynamics Corp. Defense Logistics Agency...29 6. Undersized Bits 30 7. Worn Bit Test 31 8. Stock Bit and Screw Comparison 32 9. Ribbed Bits 36 V FIELD DATA OBSERVATIONS 38 1. Torque Values 38 2

Community-oriented medical education and clinical training: comparison by medical students in hospitals.

PubMed

Ali, Azizi

2012-10-01

To determine the students' comparison of their one month educational trainings in Community-Oriented Medical Education with hospitals clinical education. Observational study. Kermanshah Community-Oriented Medical Education Field, Kermanshah University of Medical Sciences, Kermanshah, Iran, from April 2000 to February 2009. As of 2000, medical interns of Kermanshah University of Medical Sciences spend one month in the field of community-oriented medical education. At the end of the one-month period, the interns filled a questionnaire of 11 questions (based on the Likert scale) to assess the level of education in the field compared to hospital clinics. Data of questionnaires collected and completed from 2000 through 2009 (948 questionnaires) were analyzed on SPSS 18 using descriptive statistics (percentage) and analytic statistics (Chi-square test). The 948 students consisted of 66.4% males (n = 666) and 33.6% females (n = 282). All 11 variables of comparison were rated improved in the field education compared to the hospital training. The greatest difference pertained referring patients to the relevant health units (82% vs. 23.3%); patience in education (84.6% vs. 37.1%); consideration given to the three levels of prevention (77.2% vs. 33.6%) and the attention paid to the presence of students (91.7% vs. 51.8%), all of which were statistically significant (p < 0.0001). According to the interns, the educational status of specialized clinics of the field was superior to the specific clinics of hospitals (p < 0.0001). From the standpoint of medical students, training in community-oriented medical education in the field was better than training in the hospitals' clinics.

Testing strong-segregation theory against self-consistent-field theory for block copolymer melts

NASA Astrophysics Data System (ADS)

Matsen, M. W.

2001-06-01

We introduce a highly efficient self-consistent-field theory (SCFT) method for examining the cylindrical and spherical block copolymer morphologies using a standard unit cell approximation (UCA). The method is used to calculate the classical diblock copolymer phase boundaries deep into the strong-segregation regime, where they can be compared with recent improvements to strong-segregation theory (SST). The comparison suggests a significant discrepancy between the two theories indicating that our understanding of strongly stretched polymer brushes is still incomplete.

Evaluation of the Ott Hydromet Qliner for measuring discharge in laboratory and field conditions

USGS Publications Warehouse

McVay, Jason C.

2015-01-01

The U.S. Geological Survey, in collaboration with the University of Iowa IIHR – Hydroscience and Engineering, evaluated the use of the Ott Hydromet Qliner using laboratory flume tests along with field validation tests. Analysis of the flume testing indicates the velocities measured by the Qliner at a 40-second exposure time results in higher dispersion of velocities from the mean velocity of data collected with a 5-minute exposure time. The percent data spread from the mean of a 100-minute mean of Qliner velocities for a 40-second exposure time averaged 16.6 percent for the entire vertical, and a 5-minute mean produced a 6.2 percent data spread from the 100-minute mean. This 16.6 percent variation in measured velocity would result in a 3.32 percent variation in computed discharge assuming 25 verticals while averaging 4 bins in each vertical. The flume testing also provided results that indicate the blanking distance of 0.20 meters is acceptable when using beams 1 and 2, however beam 3 is negatively biased near the transducer and the 0.20-meter blanking distance is not sufficient. Field testing included comparing the measured discharge by the Qliner to the discharge measured by a Price AA mechanical current meter and a Teledyne RDI Rio Grande 1200 kilohertz acoustic Doppler current profiler. The field tests indicated a difference between the discharges measured with the Qliner and the field reference discharge between -14.0 and 8.0 percent; however the average percent difference for all 22 field comparisons was 0.22, which was not statistically significant.

Testing of visual field with virtual reality goggles in manual and visual grasp modes.

PubMed

Wroblewski, Dariusz; Francis, Brian A; Sadun, Alfredo; Vakili, Ghazal; Chopra, Vikas

2014-01-01

Automated perimetry is used for the assessment of visual function in a variety of ophthalmic and neurologic diseases. We report development and clinical testing of a compact, head-mounted, and eye-tracking perimeter (VirtualEye) that provides a more comfortable test environment than the standard instrumentation. VirtualEye performs the equivalent of a full threshold 24-2 visual field in two modes: (1) manual, with patient response registered with a mouse click, and (2) visual grasp, where the eye tracker senses change in gaze direction as evidence of target acquisition. 59 patients successfully completed the test in manual mode and 40 in visual grasp mode, with 59 undergoing the standard Humphrey field analyzer (HFA) testing. Large visual field defects were reliably detected by VirtualEye. Point-by-point comparison between the results obtained with the different modalities indicates: (1) minimal systematic differences between measurements taken in visual grasp and manual modes, (2) the average standard deviation of the difference distributions of about 5 dB, and (3) a systematic shift (of 4-6 dB) to lower sensitivities for VirtualEye device, observed mostly in high dB range. The usability survey suggested patients' acceptance of the head-mounted device. The study appears to validate the concepts of a head-mounted perimeter and the visual grasp mode.

Defining Constellation Suit Helmet Field of View Requirements Employing a Mission Segment Based Reduction Process

NASA Technical Reports Server (NTRS)

McFarland, Shane M.

2008-01-01

Field of view has always been a design feature paramount to helmet design, and in particular space suit design, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. For Project Constellation, a slightly different approach to helmet requirement maturation was utilized; one that was less a direct function of body position and suit pressure and more a function of the mission segment in which the field of view is required. Through taxonimization of various parameters that affect suited FOV, as well as consideration for possible nominal and contingency operations during that mission segment, a reduction process was able to condense the large number of possible outcomes to only six unique field of view angle requirements that still captured all necessary variables without sacrificing fidelity. The specific field of view angles were defined by considering mission segment activities, historical performance of other suits, comparison between similar requirements (pressure visor up versus down, etc.), estimated requirements from other teams for field of view (Orion, Altair, EVA), previous field of view tests, medical data for shirtsleeve field of view performance, and mapping of visual field data to generate 45degree off-axis field of view requirements. Full resolution of several specific field of view angle requirements warranted further work, which consisted of low and medium fidelity field of view testing in the rear entry ISuit and DO27 helmet prototype. This paper serves to document this reduction progress and followup testing employed to write the Constellation requirements for helmet field of view.

Field trial of a Doppler sonar system for fisheries applications

NASA Astrophysics Data System (ADS)

Tollefsen, Cristina D. S.; Zedel, Len

2003-10-01

Various deployments of commercial Doppler current profiling systems have demonstrated that these instruments can detect fish and measure their swimming speeds. However, research into the possible application of Doppler sonar to fisheries problems is limited and has not taken advantage of coherent signal processing schemes. A field trial was undertaken in August 2002 to explore the capabilities of a coherent Doppler sonar when applied to detecting discrete targets. The passage of migrating salmon on the Fraser River in British Columbia provided an ideal test opportunity with fish of well-defined swimming behavior and allowed for comparisons with conventional fisheries acoustics techniques. The instrument tested was a 250-kHz sonar which provided for phase coding of transmit pulses and coherent sampling of successive acoustic returns. The field trial resulted in 11 consecutive days of Doppler sonar data acquired during the peak of the sockeye salmon (Oncorhynchus nerka) migration. A total of 7425 individual fish were identified and their swimming speed was measured with an accuracy of between 10 cms-1 and 20 cms-1, which depended on pulse length, pulse spacing, and target range. By comparison, water velocity measurements made with the same instrument can only achieve a theoretical accuracy of 60 cms-1.

Comparison of Reduced Displacement Potentials from Spe Free Field Measurements: SPE-4PRIME Versus Previous Events

NASA Astrophysics Data System (ADS)

Patton, H. J.; Rougier, E.

2015-12-01

Since 2010, the U. S. Department of Energy has funded a series of chemical tests at the National Nuclear Security Site (NNSS) in Climax Stock granite as part of the Source Physics Experiment (SPE) with the aim of gaining a better understanding of the generation and propagation of seismic energy from underground explosions in hard rock media. To date, four tests have been conducted in the same borehole with yields of 100, 1000, 900 and 100 kg at different depths of burials. The nominal scaled depths of burial are 938, 363, 376 and 1556 m/kt1/3 compared to standard containment practices of ~120 m/kt1/3. A quite dense array of free field accelerometers were installed around the borehole, both on and off shot depth. Acceleration data were corrected for shock-generated baseline-shifts, and free field ground velocity waveforms were obtained. This work concentrates on the qualitative analysis of the reduced displacement potentials and the explosion source spectra for the last shot of the series (SPE-4Prime) and the comparison of the obtained results against the previous events. Finally, the results obtained from the experimental data are compared to the Mueller-Murphy empirical explosion model both using the Heard and Ackerman and Denny and Johnson cavity radius scaling laws.

Antigenic and genetic comparison of foot-and-mouth disease virus serotype O Indian vaccine strain, O/IND/R2/75 against currently circulating viruses

PubMed Central

Mahapatra, Mana; Yuvaraj, S.; Madhanmohan, M.; Subramaniam, S.; Pattnaik, B.; Paton, D.J.; Srinivasan, V.A.; Parida, Satya

2015-01-01

Foot-and-mouth disease (FMD) virus serotype O is the most common cause of FMD outbreaks in India and three of the six lineages that have been described are most frequently detected, namely Ind2001, PanAsia and PanAsia 2. We report the full capsid sequence of 21 serotype O viruses isolated from India between 2002 and 2012. All these viruses belong to the Middle East–South Asia (ME–SA) topotype. The serological cross-reactivity of a bovine post-vaccination serum pool raised against the current Indian vaccine strain, O/IND/R2/75,was tested by virus neutralisation test with the 23 Indian field isolates, revealing a good match between the vaccine and the field isolates. The cross reactivity of the O/IND/R2/75 vaccine with 19 field isolates from other countries (mainly from Asia and Africa) revealed a good match to 79% of the viruses indicating that the vaccine strain is broadly cross-reactive and could be used to control FMD in other countries. Comparison of the capsid sequences of the serologically non-matching isolates with the vaccine strain sequence identified substitutions in neutralising antigenic sites 1 and 2, which could explain the observed serological differences. PMID:25500306

Comparison of curricula in radiation technology in the field of radiotherapy in selected European Union countries.

PubMed

Janaszczyk, Agnieszka; Bogusz-Czerniewicz, Marta

2011-01-01

Radiation technology is a discipline of medical science which deals with diagnostics, imaging and radiotherapy, that is treatment by ionizing radiation. To present and compare the existing curricula of radiation technology in selected EU countries. The research work done for the purpose of the comparative analysis was based on the methods of diagnostic test and document analysis. The comparison of curricula in selected countries, namely Austria, France, the Netherlands and Poland, showed that admission criteria to radiation technology courses are varied and depend on regulations of respective Ministries of Health. The most restrictive conditions, including written tests in biology, chemistry and physics, and psychometric test, are those in France. Contents of basic and specialist subject groups are very similar in all the countries. The difference is in the number of ECT points assigned to particular subjects and the number of course hours offered. The longest practical training is provided in the Netherlands and the shortest one in Poland. The duration of studies in the Netherlands is 4 years, while in Poland it is 3 years. Austria is the only country to offer extra practical training in quality management. Graduates in the compared EU countries have similar level of qualifications in the fields of operation of radiological equipment, radiotherapy, nuclear medicine, foreign language and specialist terminology in the field of medical and physical sciences, general knowledge of medical and physical sciences, and detailed knowledge of radiation technology.

Monitoring of piglets' open field activity and choice behaviour during the replay of maternal vocalization: a comparison between Observer and PID technique.

PubMed

Puppe, B; Schön, P C; Wendland, K

1999-07-01

The paper presents a new system for the automatic monitoring of open field activity and choice behaviour of medium-sized animals. Passive infrared motion detectors (PID) were linked on-line via a digital I/O interface to a personal computer provided with self-developed analysis software based on LabVIEW (PID technique). The set up was used for testing 18 one-week-old piglets (Sus scrofa) for their approach to their mother's nursing vocalization replayed through loudspeakers. The results were validated by comparison with a conventional Observer technique, a computer-aided direct observation. In most of the cases, no differences were seen between the Observer and PID technique regarding the percentage of stay in previously defined open field segments, the locomotor open field activity, and the choice behaviour. The results revealed that piglets are clearly attracted by their mother's nursing vocalization. The monitoring system presented in this study is thus suitable for detailed behavioural investigations of individual acoustic recognition. In general, the PID technique is a useful tool for research into the behaviour of individual animals in a restricted open field which does not rely on subjective analysis by a human observer.

Development of the mathematical model for design and verification of acoustic modal analysis methods

NASA Astrophysics Data System (ADS)

Siner, Alexander; Startseva, Maria

2016-10-01

To reduce the turbofan noise it is necessary to develop methods for the analysis of the sound field generated by the blade machinery called modal analysis. Because modal analysis methods are very difficult and their testing on the full scale measurements are very expensive and tedious it is necessary to construct some mathematical models allowing to test modal analysis algorithms fast and cheap. At this work the model allowing to set single modes at the channel and to analyze generated sound field is presented. Modal analysis of the sound generated by the ring array of point sound sources is made. Comparison of experimental and numerical modal analysis results is presented at this work.

Experimental problem solving: An instructional improvement field experiment

NASA Astrophysics Data System (ADS)

Ross, John A.; Maynes, Florence J.

An instructional program based on expert-novice differences in experimental problem-solving performance was taught to grade 6 students (N = 265). Classes of students were randomly assigned to conditions in a delayed treatment design. Performance was assessed with multiple-choice and open-ended measures of specific transfer. Between group comparisons using pretest scores as a covariate showed that treatment condition students consistently outperformed controls; similar results were revealed in the within group comparisons. The achievement of the early treatment group did not decline in tests administered one month after the posttest.

Helium gas bubble trapped in liquid helium in high magnetic field

NASA Astrophysics Data System (ADS)

Bai, H.; Hannahs, S. T.; Markiewicz, W. D.; Weijers, H. W.

2014-03-01

High magnetic field magnets are used widely in the area of the condensed matter physics, material science, chemistry, geochemistry, and biology at the National High Magnetic Field Laboratory. New high field magnets of state-of-the-art are being pursued and developed at the lab, such as the current developing 32 T, 32 mm bore fully superconducting magnet. Liquid Helium (LHe) is used as the coolant for superconducting magnets or samples tested in a high magnetic field. When the magnetic field reaches a relatively high value the boil-off helium gas bubble generated by heat losses in the cryostat can be trapped in the LHe bath in the region where BzdBz/dz is less than negative 2100 T2/m, instead of floating up to the top of LHe. Then the magnet or sample in the trapped bubble region may lose efficient cooling. In the development of the 32 T magnet, a prototype Yttrium Barium Copper Oxide coil of 6 double pancakes with an inner diameter of 40 mm and an outer diameter of 140 mm was fabricated and tested in a resistive magnet providing a background field of 15 T. The trapped gas bubble was observed in the tests when the prototype coil was ramped up to 7.5 T at a current of 200 A. This letter reports the test results on the trapped gas bubble and the comparison with the analytical results which shows they are in a good agreement.

Performance analysis of the toroidal field ITER production conductors

NASA Astrophysics Data System (ADS)

Breschi, M.; Macioce, D.; Devred, A.

2017-05-01

The production of the superconducting cables for the toroidal field (TF) magnets of the ITER machine has recently been completed at the manufacturing companies selected during the previous qualification phase. The quality assurance/quality control programs that have been implemented to ensure production uniformity across numerous suppliers include performance tests of several conductor samples from selected unit lengths. The short full-size samples (4 m long) were subjected to DC and AC tests in the SULTAN facility at CRPP in Villigen, Switzerland. In a previous work the results of the tests of the conductor performance qualification samples were reported. This work reports the analyses of the results of the tests of the production conductor samples. The results reported here concern the values of current sharing temperature, critical current, effective strain and n-value from the DC tests and the energy dissipated per cycle from the AC loss tests. A detailed comparison is also presented between the performance of the conductors and that of their constituting strands.

Effect of reaction control system jet-flow field interactions on a 0.015 scale model space shuttle orbiter aerodynamic characteristics

NASA Technical Reports Server (NTRS)

Monta, W. J.; Rausch, J. R.

1973-01-01

The effects of the reaction control system (RCS) jet-flow field interactions on the space shuttle orbiter system during entry are discussed. The primary objective of the test program was to obtain data for the shuttle orbiter configuration to determine control amplification factors resulting from jet interaction between the RCS plumes and the external flow over the vehicle. A secondary objective was to provide data for comparison and improvement of analytic jet interaction prediction techniques. The test program was divided into two phases; (1) force and moment measurements were made with and without RCS blowing, investigating environment parameters (R sub e, Alpha, Beta), RCS plume parameters (Jet pressure ratio, momentum ratio and thrust level), and geometry parameters (RCS pod locations) on the orbiter model, (2) oil flow visualization tests were conducted on a dummy balance at the end of the test.

Modelling and scale-up of chemical flooding: First annual report for the period October 1985-September 1986

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pope, G.A.; Lake, L.W.; Sepehrnoori, K.

1987-07-01

This report consists of three parts. Part A describes the development of our chemical flood simulator UTCHEM during the past year, simulation studies, and physical property modelling and experiments. Part B is a report on the optimization and vectorization of UTCHEM on our Cray supercomputer to speed it up. Part C describes our use of UTCHEM to investigate the use of tracers for interwell reservoir tests. Part A of this Annual Report consists of five sections. In the first section, we give a general description of the simulator and recent changes in it along with a test case for amore » slightly compressible fluid. In the second section, we describe the major changes which were needed to add gel and alkaline reactions and give preliminary simulation results for these processes. In the third section, comparisons with a surfactant pilot field test are given. In the fourth section, process scaleup and design simulations are given and also our recent mesh refinement results. In the fifth section, experimental results and associated physical property modelling studies are reported. Part B gives our results on the speedup of UTCHEM on a Cray supercomputer. Depending on the size of the problem, this speedup factor was at least tenfold and resulted from a combination of a faster solver, vectorization, and code optimization. Part C describes our use of UTCHEM for field tracer studies and gives the results of a comparison with field tracer data on the same field (Big Muddy) as was simulated and compared with the surfactant pilot reported in section 3 of Part A. 120 figs., 37 tabs.« less

Outcomes of Parent Education Programs Based on Reevaluation Counseling

ERIC Educational Resources Information Center

Wolfe, Randi B.; Hirsch, Barton J.

2003-01-01

We report two studies in which a parent education program based on Reevaluation Counseling was field-tested on mothers randomly assigned to treatment groups or equivalent, no-treatment comparison groups. The goal was to evaluate the program's viability, whether there were measurable effects, whether those effects were sustained over time, and…

Biodegradation of the surfactant linear alkylbenzenesulfonate in sewage- contaminated groundwater: A comparison of column experiments and field tracer tests

USGS Publications Warehouse

Krueger, C.J.; Radakovich, K.M.; Sawyer, T.E.; Barber, L.B.; Smith, R.L.; Field, J.A.

1998-01-01

Transport and biodegradation of linear alkylbenzenesulfonate (LAS) in sewage-contaminated groundwater were investigated for a range of dissolved oxygen concentrations. Both laboratory column and an 80-day continuous injection tracer test field experiments were conducted. The rates of LAS biodegradation increased with increasing dissolved oxygen concentrations and indicated the preferential biodegradation of the longer alkyl chain LAS homologues (i.e., C12 and C13) and external isomers (i.e., 2-and 3- phenyl). However, for similar dissolved oxygen concentrations, mass removal rates for LAS generally were 2-3 times greater in laboratory column experiments than in the field tracer test. Under low oxygen conditions (<1 mg/L) only a fraction of the LAS mixture biodegraded in both laboratory and field experiments. Biodegradation rate constants for the continuous injection field test (0.002-0.08 day-1) were comparable to those estimated for a 3-h injection (pulsed) tracer test conducted under similar biogeochemical conditions, indicating that increasing the exposure time of aquifer sediments to LAS did not increase biodegradation rates.Transport and biodegradation of linear alkylbenzenesulfonate (LAS) in sewage-contaminated groundwater were investigated for a range of dissolved oxygen concentrations. Both laboratory column and an 80-day continuous injection tracer test field experiments were conducted. The rates of LAS biodegradation increased with increasing dissolved oxygen concentrations and indicated the preferential biodegradation of the longer alkyl chain LAS homologues (i.e., C12 and C13) and external isomers (i.e., 2- and 3-phenyl). However, for similar dissolved oxygen concentrations, mass removal rates for LAS generally were 2-3 times greater in laboratory column experiments than in the field tracer test. Under low oxygen conditions (<1 mg/L) only a fraction of the LAS mixture biodegraded in both laboratory and field experiments. Biodegradation rate constants for the continuous injection field test (0.002-0.08 day-1) were comparable to those estimated for a 3-h injection (pulsed) tracer test conducted under similar biogeochemical conditions, indicating that increasing the exposure time of aquifer sediments to LAS did not increase biodegradation rates.

The effect of forward speed on J85 engine noise from suppressor nozzles as measured in the NASA-Ames 40- by 80-foot wind tunnel

NASA Technical Reports Server (NTRS)

Atencio, A., Jr.

1977-01-01

An investigation to determine the effect of forward speed on the exhaust noise from a conical ejector nozzle and three suppressor nozzles mounted behind a J85 engine was performed in a 40- by 80-foot wind tunnel. The nozzles were tested at three engine power settings and at wind tunnel forward speeds up to 91 m/sec (300 ft/sec). In addition, outdoor static tests were conducted to determine (1) the differences between near field and far field measurements, (2) the effect of an airframe on the far field directivity of each nozzle, and (3) the relative suppression of each nozzle with respect to the baseline conical ejector nozzle. It was found that corrections to near field data are necessary to extrapolate to far field data and that the presence of the airframe changed the far field directivity as measured statically. The results show that the effect of forward speed was to reduce the noise from each nozzle more in the area of peak noise, but the change in forward quadrant noise was small or negligible. A comparison of wind tunnel data with available flight test data shows good agreement.

Identification and prioritization of rail squat defects in the field using rail magnetisation technology

NASA Astrophysics Data System (ADS)

Kaewunruen, Sakdirat

2015-04-01

Inevitably, rail squats and studs are continuing to be a serious problem for railway organisations around the world in the 21st century. They are typically classified as the growth of any cracks that have grown longitudinally through the subsurface and some of the cracks propagating to the bottom of rails transversely, and have branched from initial longitudinal cracks with a depression of rail surface. The horizontal crack, which results in a depression of rail surface, induces increased maintenance level, more frequent monitoring, compromised rail testing (as the crack shields the signal echoes), and possible broken rails. This paper presents field investigations using a magnetised-rail testing device developed by MRX Technologies to identify and prioritise the rail squats. Most of the in situ squats were found on the high rail of the transition (variable-radius curved track), which is associated with rolling contact fatigue (RCF). This investigation highlights the field performance of the MRX's surface crack detection technology in comparison with the traditional ultrasonic method and detailed walking inspection. Visually, it was found in the field that the size of the RCF squats varies from very small to moderate. The predicted crack data were obtained by scanning the magnitised rails. The comparison of the actual crack depths (ultrasonic) and the predicted crack depths (MRX device) shows: • A possible correlation for small RCF/ squat cracks. • Poor interpretation of larger defects and welds. The field assessment also suggests some practical issues required for further development, including the detection of rail spalling, deep transverse crack, welding, and so on.

3D digital image correlation methods for full-field vibration measurement

NASA Astrophysics Data System (ADS)

Helfrick, Mark N.; Niezrecki, Christopher; Avitabile, Peter; Schmidt, Timothy

2011-04-01

In the area of modal test/analysis/correlation, significant effort has been expended over the past twenty years in order to make reduced models and to expand test data for correlation and eventual updating of the finite element models. This has been restricted by vibration measurements which are traditionally limited to the location of relatively few applied sensors. Advances in computers and digital imaging technology have allowed 3D digital image correlation (DIC) methods to measure the shape and deformation of a vibrating structure. This technique allows for full-field measurement of structural response, thus providing a wealth of simultaneous test data. This paper presents some preliminary results for the test/analysis/correlation of data measured using the DIC approach along with traditional accelerometers and a scanning laser vibrometer for comparison to a finite element model. The results indicate that all three approaches correlated well with the finite element model and provide validation for the DIC approach for full-field vibration measurement. Some of the advantages and limitations of the technique are presented and discussed.

Toxicity of an herbicide and adjuvant to saltmarsh invertebrates in the management of invasive grass; Comparative laboratory and field tests.

PubMed

Kleinhenz, Linda S; Nugegoda, Dayanthi; Verspaandonk, Emily R; Coombes, Darcy C; Howe, Steffan; Shimeta, Jeff

2016-08-15

Coastal weeds are often treated with herbicides without knowledge of non-target impacts, and toxicity data from standardized test species can have limited applicability. We evaluated toxicity to invertebrates from Fusilade Forte® and the adjuvant Hasten® in the control of invasive salt marsh grass, Spartina anglica. For 3 of 4 local invertebrates, Fusilade Forte® was moderately toxic (96h LC50 5.4-144mgL(-1)), whereas Hasten® was less toxic (14.2-450mgL(-1)). For most species, the mixture was more toxic than the herbicide alone, with 96h LC50 reduced 23-45%. However, a field experiment applying typical concentrations (1000×the lowest 96h LC50) showed low concentrations of herbicide residues and no detrimental impacts on invertebrates over 6months. The results reveal the importance of testing locally relevant species for potential toxicity, and of comparison tests with field exposures to determine the realised toxicity in nature. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of Dynamic Balance in Collegiate Field Hockey and Football Players Using Star Excursion Balance Test

PubMed Central

Bhat, Rashi; Moiz, Jamal Ali

2013-01-01

Purpose The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. Methods A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. Results There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Conclusion Field hockey players and football players did not differ in terms of dynamic balance. PMID:24427482

Comparison of dynamic balance in collegiate field hockey and football players using star excursion balance test.

PubMed

Bhat, Rashi; Moiz, Jamal Ali

2013-09-01

The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Field hockey players and football players did not differ in terms of dynamic balance.

Comparison of three methods of solution to the inverse problem of groundwater hydrology for multiple pumping stimulation

NASA Astrophysics Data System (ADS)

Giudici, Mauro; Casabianca, Davide; Comunian, Alessandro

2015-04-01

The basic classical inverse problem of groundwater hydrology aims at determining aquifer transmissivity (T ) from measurements of hydraulic head (h), estimates or measures of source terms and with the least possible knowledge on hydraulic transmissivity. The theory of inverse problems shows that this is an example of ill-posed problem, for which non-uniqueness and instability (or at least ill-conditioning) might preclude the computation of a physically acceptable solution. One of the methods to reduce the problems with non-uniqueness, ill-conditioning and instability is a tomographic approach, i.e., the use of data corresponding to independent flow situations. The latter might correspond to different hydraulic stimulations of the aquifer, i.e., to different pumping schedules and flux rates. Three inverse methods have been analyzed and tested to profit from the use of multiple sets of data: the Differential System Method (DSM), the Comparison Model Method (CMM) and the Double Constraint Method (DCM). DSM and CMM need h all over the domain and thus the first step for their application is the interpolation of measurements of h at sparse points. Moreover, they also need the knowledge of the source terms (aquifer recharge, well pumping rates) all over the aquifer. DSM is intrinsically based on the use of multiple data sets, which permit to write a first-order partial differential equation for T , whereas CMM and DCM were originally proposed to invert a single data set and have been extended to work with multiple data sets in this work. CMM and DCM are based on Darcy's law, which is used to update an initial guess of the T field with formulas based on a comparison of different hydraulic gradients. In particular, the CMM algorithm corrects the T estimate with ratio of the observed hydraulic gradient and that obtained with a comparison model which shares the same boundary conditions and source terms as the model to be calibrated, but a tentative T field. On the other hand the DCM algorithm applies the ratio of the hydraulic gradients obtained for two different forward models, one with the same boundary conditions and source terms as the model to be calibrated and the other one with prescribed head at the positions where in- or out-flow is known and h is measured. For DCM and CMM, multiple stimulation is used by updating the T field separately for each data set and then combining the resulting updated fields with different possible statistics (arithmetic, geometric or harmonic mean, median, least change, etc.). The three algorithms are tested and their characteristics and results are compared with a field data set, which was provided by prof. Fritz Stauffer (ETH) and corresponding to a pumping test in a thin alluvial aquifer in northern Switzerland. Three data sets are available and correspond to the undisturbed state, to the flow field created by a single pumping well and to the situation created by an 'hydraulic dipole', i.e., an extraction and an injection wells. These data sets permit to test the three inverse methods and the different options which can be chosen for their use.

Comparison of Tomo-PIV Versus Dual Plane PIV on a Synthetic Jet Flow

NASA Technical Reports Server (NTRS)

Wernet, Mark P.

2017-01-01

Particle Imaging Velocimetry (PIV) is a planar velocity measurement technique that has found widespread use across a wide class of engineering disciplines. Tomographic PIV (tomoPIV) is an extension of the traditional PIV technique whereby the velocity across a volume of fluid is measured. TomoPIV provides additional fluid mechanical properties of the flow due to the adjacent planes of velocity information that are extracted. Dual Plane PIV is another approach for providing cross-plane flow field properties. Dual Plane PIV and tomoPIV provide all of the same flow properties, albeit through very different routes with significantly different levels of effort, hence a comparison of their application and performance would prove beneficial in a well-known, highly three dimensional flow field. A synthetic jet flow which has a wide range of flow field features including high velocity gradients and regions of high vorticity was used as a rigorous test bed to determine the capabilities limitations of the Dual Plane PIV and tomoPIV techniques. The results show that compressing 3D particle field information down to a limited number of views does not permit the accurate reconstruction of the flow field. The traditional thin sheet techniques are the best approach for accurate flow field measurements.

TOP 04-1-010 Effectiveness Testing of Mechanical Clearing Systems - Roller Systems Operating in a Straight Path

DTIC Science & Technology

2017-12-04

36 APPENDIX A. TEST LANE DESIGN AND CONFUGURATION ............. A-1 B. EXAMPLE CHECKLISTS AND DATA SHEETS ............. B-1 C. ROLLER...categories and configurations, burial depths, etc.) allow for direct comparison of systems, from legacy systems (fielded) to new designs not having...effectiveness assessment of the SUT, but may indicate shortfall or design deficiency of the SUT in the integration to a specific PM, or a safety flag

Testing algorithms for critical slowing down

NASA Astrophysics Data System (ADS)

Cossu, Guido; Boyle, Peter; Christ, Norman; Jung, Chulwoo; Jüttner, Andreas; Sanfilippo, Francesco

2018-03-01

We present the preliminary tests on two modifications of the Hybrid Monte Carlo (HMC) algorithm. Both algorithms are designed to travel much farther in the Hamiltonian phase space for each trajectory and reduce the autocorrelations among physical observables thus tackling the critical slowing down towards the continuum limit. We present a comparison of costs of the new algorithms with the standard HMC evolution for pure gauge fields, studying the autocorrelation times for various quantities including the topological charge.

Repeatability and validity of a field kit for estimation of cholinesterase in whole blood.

PubMed Central

London, L; Thompson, M L; Sacks, S; Fuller, B; Bachmann, O M; Myers, J E

1995-01-01

OBJECTIVES--To evaluate a spectrophotometric field kit (Test-Mate-OP) for repeatability and validity in comparison with reference laboratory methods and to model its anticipated sensitivity and specificity based on these findings. METHODS--76 farm workers between the age of 20 and 55, of whom 30 were pesticide applicators exposed to a range of organophosphates in the preceding 10 days, had blood taken for plasma cholinesterase (PCE) and erythrocyte cholinesterase (ECE) measurement by field kit or laboratory methods. Paired blinded duplicate samples were taken from subgroups in the sample to assess repeatability of laboratory and field kit methods. Field kits were also used to test venous blood in one subgroup. The variance obtained for the field kit tests was then applied to two hypothetical scenarios that used published action guidelines to model the kit's sensitivity and specificity. RESULTS--Repeatability for PCE was much poorer and for ECE slightly poorer than that of laboratory measures. A substantial upward bias for field kit ECE relative to laboratory measurements was found. Sensitivity of the kit to a 40% drop in PCE was 67%, whereas that for ECE was 89%. Specificity of the kit with no change in mean of the population was 100% for ECE and 91% for PCE. CONCLUSION--Field kit ECE estimation seems to be sufficiently repeatable for surveillance activities, whereas PCE does not. Repeatability of both tests seems to be too low for use in epidemiological dose-response investigations. Further research is indicated to characterise the upward bias in ECE estimation on the kit. PMID:7697143

Turbomachinery noise studies of the AiResearch QCGAT engine with inflow control

NASA Technical Reports Server (NTRS)

Mcardle, J. G.; Homyak, L.; Chrulski, D. D.

1981-01-01

The AiResearch Quiet Clean General Aviation Turbofan engine was tested on an outdoor test stand to compare the acoustic performance of two inflow control devices (ICD's) of similar design, and three inlet lips of different external shape. Only small performance differences were found. Far-field directivity patterns calculated by applicable existing analyses were compared with the measured tone and broadband patterns. For some of these comparisons, tests were made with an ICD to reduce rotor/inflow disturbance interaction noise, or with the acoustic suppression panels in the inlet or bypass duct covered with aluminum tape to determine hard wall acoustic performance. The comparisons showed that the analytical expressions used predict many directivity pattern features and trends, but can deviate in shape from the measured patterns under certain engine operating conditions. Some patterns showed lobes from modes attributable to rotor/engine strut interaction sources.

Microstructure, Mechanical Properties, and Corrosion Resistance of Thermomechanically Processed AlZn6Mg0.8Zr Alloy

PubMed Central

Kowalski, Aleksander; Ozgowicz, Wojciech; Jurczak, Wojciech; Grajcar, Adam; Boczkal, Sonia; Żelechowski, Janusz

2018-01-01

The paper presents results of the investigations on the effect of low-temperature thermomechanical treatment (LTTT) on the microstructure of AlZn6Mg0.8Zr alloy (7000 series) and its mechanical properties as well as electrochemical and stress corrosion resistance. For comparison of the LTTT effect, the alloy was subjected to conventional precipitation hardening. Comparative studies were conducted in the fields of metallographic examinations and static tensile tests. It was found that mechanical properties after the LTTT were better in comparison to after conventional heat treatment (CHT). The tested alloy after low-temperature thermomechanical treatment with increasing plastic deformation shows decreased electrochemical corrosion resistance during potentiodynamic tests. The alloy after low-temperature thermomechanical treatment with deformation degree in the range of 10 to 30% is characterized by a high resistance to stress corrosion specified by the level of PSCC indices. PMID:29642448

Longitudinally Jointed Edge-Wise Compression HoneyComb Composite Sandwich Coupon Testing And Fe Analysis: Three Methods of Strain Measurement, And Comparison

NASA Technical Reports Server (NTRS)

Farrokh, Babak; Rahim, Nur Aida Abul; Segal, Ken; Fan, Terry; Jones, Justin; Hodges, Ken; Mashni, Noah; Garg, Naman; Sang, Alex

2013-01-01

Three distinct strain measurement methods (i.e., foil resistance strain gages, fiber optic strain sensors, and a three-dimensional digital image photogrammetry that gives full field strain and displacement measurements) were implemented to measure strains on the back and front surfaces of a longitudinally jointed curved test article subjected to edge-wise compression testing, at NASA Goddard Space Flight Center, according to ASTM C364. The pre-test finite element analysis (FEA) was conducted to assess ultimate failure load and predict strain distribution pattern throughout the test coupon. The predicted strain pattern contours were then utilized as guidelines for installing the strain measurement instrumentations. The foil resistance strain gages and fiber optic strain sensors were bonded on the specimen at locations with nearly the same analytically predicted strain values, and as close as possible to each other, so that, comparisons between the measured strains by strain gages and fiber optic sensors, as well as the three-dimensional digital image photogrammetric system are relevant. The test article was loaded to failure (at 167 kN), at the compressive strain value of 10,000 micro epsilon. As a part of this study, the validity of the measured strains by fiber optic sensors is examined against the foil resistance strain gages and the three-dimensional digital image photogrammetric data, and comprehensive comparisons are made with FEA predictions.

MO-F-16A-01: Implementation of MPPG TPS Verification Tests On Various Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smilowitz, J; Bredfeldt, J; Geurts, M

2014-06-15

Purpose: To demonstrate the implementation of the Medical Physics Practice Guideline (MPPG) for dose calculation and beam parameters verification of treatment planning systems (TPS). Methods: We implemented the draft TPS MPPG for three linacs: Varian Trilogy, TomoHDA and Elekta Infinity. Static and modulated test plans were created. The static fields are different than used in commissioning. Data was collected using ion chambers and diodes in a scanning water tank, Delta4 phantom and a custom phantom. MatLab and Microsoft Excel were used to create analysis tools to compare reference DICOM dose with scan data. This custom code allowed for the interpolation,more » registration and gamma analysis of arbitrary dose profiles. It will be provided as open source code. IMRT fields were validated with Delta4 registration and comparison tools. The time for each task was recorded. Results: The tests confirmed the strengths, and revealed some limitations, of our TPS. The agreement between calculated and measured dose was reported for all beams. For static fields, percent depth dose and profiles were analyzed with criteria in the draft MPPG. The results reveal areas of slight mismatch with the model (MLC leaf penumbra, buildup region.) For TomoTherapy, the IMRT plan 2%/2 mm gamma analysis revealed poorest agreement in the low dose regions. For one static test plan for all 10MV Trilogy photon beams, the plan generation, scan queue creation, data collection, data analysis and report took 2 hours, excluding tank setup. Conclusions: We have demonstrated the implementation feasibility of the TPS MPPG. This exercise generated an open source tool for dose comparisons between scan data and DICOM dose data. An easily reproducible and efficient infrastructure with streamlined data collection was created for repeatable robust testing of the TPS. The tests revealed minor discrepancies in our models and areas for improvement that are being investigated.« less

Relationship between second-generation frequency doubling technology and standard automated perimetry in patients with glaucoma.

PubMed

Zarkovic, Andrea; Mora, Justin; McKelvie, James; Gamble, Greg

2007-12-01

The aim of the study was to establish the correlation between visual filed loss as shown by second-generation Frequency Doubling Technology (Humphrey Matrix) and Standard Automated Perimetry (Humphrey Field Analyser) in patients with glaucoma. Also, compared were the test duration and reliability. Forty right eyes from glaucoma patients from a private ophthalmology practice were included in this prospective study. All participants had tests within an 8-month period. Pattern deviation plots and mean deviation were compared to establish the correlation between the two perimetry tests. Overall correlation and correlation between hemifields, quadrants and individual test locations were assessed. Humphrey Field Analyser tests were slightly more reliable (37/40 vs. 34/40 for Matrix)) but overall of longer duration. There was good correlation (0.69) between mean deviations. Superior hemifields and superonasal quadrants had the highest correlation (0.88 [95% CI 0.79, 0.94]). Correlation between individual points was independent of distance from the macula. Generally, the Matrix and Humphrey Field Analyser perimetry correlate well; however, each machine utilizes a different method of analysing data and thus the direct comparison should be made with caution.

FAST Model Calibration and Validation of the OC5-DeepCwind Floating Offshore Wind System Against Wave Tank Test Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wendt, Fabian F; Robertson, Amy N; Jonkman, Jason

During the course of the Offshore Code Comparison Collaboration, Continued, with Correlation (OC5) project, which focused on the validation of numerical methods through comparison against tank test data, the authors created a numerical FAST model of the 1:50-scale DeepCwind semisubmersible system that was tested at the Maritime Research Institute Netherlands ocean basin in 2013. This paper discusses several model calibration studies that were conducted to identify model adjustments that improve the agreement between the numerical simulations and the experimental test data. These calibration studies cover wind-field-specific parameters (coherence, turbulence), hydrodynamic and aerodynamic modeling approaches, as well as rotor model (blade-pitchmore » and blade-mass imbalances) and tower model (structural tower damping coefficient) adjustments. These calibration studies were conducted based on relatively simple calibration load cases (wave only/wind only). The agreement between the final FAST model and experimental measurements is then assessed based on more-complex combined wind and wave validation cases.« less

Putting atomic diffusion theory of magnetic ApBp stars to the test: evaluation of the predictions of time-dependent diffusion models

NASA Astrophysics Data System (ADS)

Kochukhov, O.; Ryabchikova, T. A.

2018-02-01

A series of recent theoretical atomic diffusion studies has address the challenging problem of predicting inhomogeneous vertical and horizontal chemical element distributions in the atmospheres of magnetic ApBp stars. Here we critically assess the most sophisticated of such diffusion models - based on a time-dependent treatment of the atomic diffusion in a magnetized stellar atmosphere - by direct comparison with observations as well by testing the widely used surface mapping tools with the spectral line profiles predicted by this theory. We show that the mean abundances of Fe and Cr are grossly underestimated by the time-dependent theoretical diffusion model, with discrepancies reaching a factor of 1000 for Cr. We also demonstrate that Doppler imaging inversion codes, based either on modelling of individual metal lines or line-averaged profiles simulated according to theoretical three-dimensional abundance distribution, are able to reconstruct correct horizontal chemical spot maps despite ignoring the vertical abundance variation. These numerical experiments justify a direct comparison of the empirical two-dimensional Doppler maps with theoretical diffusion calculations. This comparison is generally unfavourable for the current diffusion theory, as very few chemical elements are observed to form overabundance rings in the horizontal field regions as predicted by the theory and there are numerous examples of element accumulations in the vicinity of radial field zones, which cannot be explained by diffusion calculations.

Plasma Wake-field Acceleration in the Blow-out Regime

NASA Astrophysics Data System (ADS)

Barov, Nikolai; Rosenzweig, James

1999-11-01

Recent experiments at Argonne National Laboratory, investigating the blow-out regime of the plasma wake-field accelerator, are discussed. These experiments achieved stable underdense (beam denser than the ambient plasma density) beam transport, and measured average acceleration of 25 MV/m, corresponding to peak wave fields of over 60 MVm. A comparison of the results to simulation is given, and the physics of the system is discussed. Potential for improvements in performance and achieved acceleration gradient, as well as accelerated beam quality are examined within the context of the next generation of experiments at the Fermilab Test Facility. The status of these experiments will be given.

Comparison of electric field exposure monitoring instrumentation. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bracken, T.D.

1985-06-01

Electric field exposure monitoring instrumentation was compared and evaluated during three days of tests performed in 60-Hz electric fields. A conducting vest exposure meter and a small electric field exposure meter (EFEM) located in a shirt pocket, arm band or hard hat were compared in a series of static and dynamic tests. In some tests, the devices were worn simultaneously without interference to provide separate measures of identical exposure. Tests with stationary subjects wearing the instruments were used to measure the effects of grounding, and to establish the meter response in a standard posture for each subject. Dynamic occupational exposuremore » simulations were used to compare accumulated measurements of exposure between instruments and to compare measurements with predicted exposures. The simulations were based on analysis of the work-related behavior of substation electricians and operators. Electrician's tasks at ground level and in a bucket truck were simulated near an energized test line. A simulated substation inspection was performed in a 230 kV substation. The exposure measurements demonstrated an overall consistency between the meters. The vest demonstrated less intersubject variability and less detailed exposure characterization. Measurements with the shirt pocket EFEM were below those made with the vest and with the EFEM in other locations. Insulation provided by shoe soles appeared to be the largest factor in reducing measured exposures during the substation inspection below those predicted from the unperturbed field. Improvements in meter design and additional measurements are suggested. 11 refs., 20 figs., 28 tabs.« less

A Super-Resolution Algorithm for Enhancement of FLASH LIDAR Data: Flight Test Results

NASA Technical Reports Server (NTRS)

Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Eric; Reisse Robert

2014-01-01

This paper describes the results of a 3D super-resolution algorithm applied to the range data obtained from a recent Flash Lidar helicopter flight test. The flight test was conducted by the NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project over a simulated lunar terrain facility at NASA Kennedy Space Center. ALHAT is developing the technology for safe autonomous landing on the surface of celestial bodies: Moon, Mars, asteroids. One of the test objectives was to verify the ability of 3D super-resolution technique to generate high resolution digital elevation models (DEMs) and to determine time resolved relative positions and orientations of the vehicle. 3D super-resolution algorithm was developed earlier and tested in computational modeling, and laboratory experiments, and in a few dynamic experiments using a moving truck. Prior to the helicopter flight test campaign, a 100mX100m hazard field was constructed having most of the relevant extraterrestrial hazard: slopes, rocks, and craters with different sizes. Data were collected during the flight and then processed by the super-resolution code. The detailed DEM of the hazard field was constructed using independent measurement to be used for comparison. ALHAT navigation system data were used to verify abilities of super-resolution method to provide accurate relative navigation information. Namely, the 6 degree of freedom state vector of the instrument as a function of time was restored from super-resolution data. The results of comparisons show that the super-resolution method can construct high quality DEMs and allows for identifying hazards like rocks and craters within the accordance of ALHAT requirements.

A super-resolution algorithm for enhancement of flash lidar data: flight test results

NASA Astrophysics Data System (ADS)

Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Eric; Reisse, Robert

2013-03-01

This paper describes the results of a 3D super-resolution algorithm applied to the range data obtained from a recent Flash Lidar helicopter flight test. The flight test was conducted by the NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project over a simulated lunar terrain facility at NASA Kennedy Space Center. ALHAT is developing the technology for safe autonomous landing on the surface of celestial bodies: Moon, Mars, asteroids. One of the test objectives was to verify the ability of 3D super-resolution technique to generate high resolution digital elevation models (DEMs) and to determine time resolved relative positions and orientations of the vehicle. 3D super-resolution algorithm was developed earlier and tested in computational modeling, and laboratory experiments, and in a few dynamic experiments using a moving truck. Prior to the helicopter flight test campaign, a 100mX100m hazard field was constructed having most of the relevant extraterrestrial hazard: slopes, rocks, and craters with different sizes. Data were collected during the flight and then processed by the super-resolution code. The detailed DEM of the hazard field was constructed using independent measurement to be used for comparison. ALHAT navigation system data were used to verify abilities of super-resolution method to provide accurate relative navigation information. Namely, the 6 degree of freedom state vector of the instrument as a function of time was restored from super-resolution data. The results of comparisons show that the super-resolution method can construct high quality DEMs and allows for identifying hazards like rocks and craters within the accordance of ALHAT requirements.

Field significance of performance measures in the context of regional climate model evaluation. Part 1: temperature

NASA Astrophysics Data System (ADS)

Ivanov, Martin; Warrach-Sagi, Kirsten; Wulfmeyer, Volker

2018-04-01

A new approach for rigorous spatial analysis of the downscaling performance of regional climate model (RCM) simulations is introduced. It is based on a multiple comparison of the local tests at the grid cells and is also known as "field" or "global" significance. New performance measures for estimating the added value of downscaled data relative to the large-scale forcing fields are developed. The methodology is exemplarily applied to a standard EURO-CORDEX hindcast simulation with the Weather Research and Forecasting (WRF) model coupled with the land surface model NOAH at 0.11 ∘ grid resolution. Monthly temperature climatology for the 1990-2009 period is analysed for Germany for winter and summer in comparison with high-resolution gridded observations from the German Weather Service. The field significance test controls the proportion of falsely rejected local tests in a meaningful way and is robust to spatial dependence. Hence, the spatial patterns of the statistically significant local tests are also meaningful. We interpret them from a process-oriented perspective. In winter and in most regions in summer, the downscaled distributions are statistically indistinguishable from the observed ones. A systematic cold summer bias occurs in deep river valleys due to overestimated elevations, in coastal areas due probably to enhanced sea breeze circulation, and over large lakes due to the interpolation of water temperatures. Urban areas in concave topography forms have a warm summer bias due to the strong heat islands, not reflected in the observations. WRF-NOAH generates appropriate fine-scale features in the monthly temperature field over regions of complex topography, but over spatially homogeneous areas even small biases can lead to significant deteriorations relative to the driving reanalysis. As the added value of global climate model (GCM)-driven simulations cannot be smaller than this perfect-boundary estimate, this work demonstrates in a rigorous manner the clear additional value of dynamical downscaling over global climate simulations. The evaluation methodology has a broad spectrum of applicability as it is distribution-free, robust to spatial dependence, and accounts for time series structure.

Field test comparison of an autocorrelation technique for determining grain size using a digital 'beachball' camera versus traditional methods

USGS Publications Warehouse

Barnard, P.L.; Rubin, D.M.; Harney, J.; Mustain, N.

2007-01-01

This extensive field test of an autocorrelation technique for determining grain size from digital images was conducted using a digital bed-sediment camera, or 'beachball' camera. Using 205 sediment samples and >1200 images from a variety of beaches on the west coast of the US, grain size ranging from sand to granules was measured from field samples using both the autocorrelation technique developed by Rubin [Rubin, D.M., 2004. A simple autocorrelation algorithm for determining grain size from digital images of sediment. Journal of Sedimentary Research, 74(1): 160-165.] and traditional methods (i.e. settling tube analysis, sieving, and point counts). To test the accuracy of the digital-image grain size algorithm, we compared results with manual point counts of an extensive image data set in the Santa Barbara littoral cell. Grain sizes calculated using the autocorrelation algorithm were highly correlated with the point counts of the same images (r2 = 0.93; n = 79) and had an error of only 1%. Comparisons of calculated grain sizes and grain sizes measured from grab samples demonstrated that the autocorrelation technique works well on high-energy dissipative beaches with well-sorted sediment such as in the Pacific Northwest (r2 ??? 0.92; n = 115). On less dissipative, more poorly sorted beaches such as Ocean Beach in San Francisco, results were not as good (r2 ??? 0.70; n = 67; within 3% accuracy). Because the algorithm works well compared with point counts of the same image, the poorer correlation with grab samples must be a result of actual spatial and vertical variability of sediment in the field; closer agreement between grain size in the images and grain size of grab samples can be achieved by increasing the sampling volume of the images (taking more images, distributed over a volume comparable to that of a grab sample). In all field tests the autocorrelation method was able to predict the mean and median grain size with ???96% accuracy, which is more than adequate for the majority of sedimentological applications, especially considering that the autocorrelation technique is estimated to be at least 100 times faster than traditional methods.

Geoengineering characterization of welded tuffs from laboratory and field investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimmerman, R.M.; Nimick, F.B.; Board, M.P.

1984-12-31

Welded tuff beneath Yucca Mountain adjacent to the Nevada Test Site (NTS) is being considered for development as a high-level radioactive waste repository by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. Because access into Yucca Mountain has been limited to borehole explorations, early geoengineering materials characterizations have been derived from laboratory tests on cores from Yucca Mountain and from laboratory and field tests on welded tuffs located in G-Tunnel on the NTS. G-Tunnel contains welded tuffs that have similar properties and stress states to those at Yucca Mountain and has been the location for in situ rock mechanics testing.more » The purpose of this paper is to summarize the geoengineering material property data obtained to date and to compare appropriate laboratory and field data from G-Tunnel to findings from Yucca Mountain. Geomechanical and thermal data are provided and are augmented by limited geological and hydrological data. A comparison of results of laboratory measurements on tuffs from Yucca Mountain and G-Tunnel indicates good agreement between the bulk densities, saturations, moduli of elasticity, Poisson`s ratios, and P-wave velocities. The G-Tunnel tuff has slightly lower thermal conductivity, tensile strength, compressive strength and slightly higher matrix permeability than does the welded tuff near the proposed repository horizon at Yucca Mountain. From a laboratory-to-field scaling perspective, the modulus of deformation shows the most sensitivity to field conditions because of the presence of the joints found in the field. 14 references, 1 table.« less

Geoengineering characterization of welded tuffs from laboratory and field investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimmerman, R.M.; Nimick, F.B.; Board, M.P.

1984-12-31

Welded tuff beneath Yucca Mountain adjacent to the Nevada Test Site (NTS) is being considered for development as a high-level radioactive waste repository by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. Because access into Yucca Mountain has been limited to borehole explorations, early geoengineering materials characterizations have been derived from laboratory tests on cores from Yucca Mountain and from laboratory and field tests on welded tuffs located in G-Tunnel on the NTS. G-Tunnel contains welded tuffs that have similar properties and stress states to those at Yucca Mountain and has been the location for in situ rock mechanics testing.more » The purpose of this paper is to summarize the geoengineering material property data obtained to date and to compare appropriate laboratory and field data from G-Tunnel to findings from Yucca Mountain. Geomechanical and thermal data are provided and are augmented by limited geological and hydrological data. A comparison of results of laboratory measurements on tuffs from Yucca Mountain and G-Tunnel indicates good agreement between the bulk densities, saturations, moduli of elasticity, Poisson`s ratios, and P-wave velocities. The G-Tunnel tuff has slightly lower thermal conductivity, tensile strength, compressive strength and slightly higher matrix permeability than does the welded tuff near the proposed repository horizon at Yucca Mountain. From a laboratory-to-field scaling perspective, the modulus of deformation shows the most sensitivity to field conditions because of the presence of joints found in the field. 14 refs., 1 tab.« less

Comparison of three methods for materials identification and mapping with imaging spectroscopy

NASA Technical Reports Server (NTRS)

Clark, Roger N.; Swayze, Gregg; Boardman, Joe; Kruse, Fred

1993-01-01

We are comparing three methods of mapping analysis tools for imaging spectroscopy data. The purpose of this comparison is to understand the advantages and disadvantages of each algorithm so others would be better able to choose the best algorithm or combinations of algorithms for a particular problem. The three algorithms are: (1) the spectralfeature modified least squares mapping algorithm of Clark et al (1990, 1991): programs mbandmap and tricorder; (2) the Spectral Angle Mapper Algorithm(Boardman, 1993) found in the CU CSES SIPS package; and (3) the Expert System of Kruse et al. (1993). The comparison uses a ground-calibrated 1990 AVIRIS scene of 400 by 410 pixels over Cuprite, Nevada. Along with the test data set is a spectral library of 38 minerals. Each algorithm is tested with the same AVIRIS data set and spectral library. Field work has confirmed the presence of many of these minerals in the AVIRIS scene (Swayze et al. 1992).

Computational and experimental aftbody flow fields for hypersonic, airbreathing configurations with scramjet exhaust flow simulation

NASA Technical Reports Server (NTRS)

Huebner, Lawrence D.; Tatum, Kenneth E.

1991-01-01

Computational results are presented for three issues pertinent to hypersonic, airbreathing vehicles employing scramjet exhaust flow simulation. The first issue consists of a comparison of schlieren photographs obtained on the aftbody of a cruise missile configuration under powered conditions with two-dimensional computational solutions. The second issue presents the powered aftbody effects of modeling the inlet with a fairing to divert the external flow as compared to an operating flow-through inlet on a generic hypersonic vehicle. Finally, a comparison of solutions examining the potential of testing powered configurations in a wind-off, instead of a wind-on, environment, indicate that, depending on the extent of the three-dimensional plume, it may be possible to test aftbody powered hypersonic, airbreathing configurations in a wind-off environment.

Effect of wake structure on blade-vortex interaction phenomena: Acoustic prediction and validation

NASA Technical Reports Server (NTRS)

Gallman, Judith M.; Tung, Chee; Schultz, Klaus J.; Splettstoesser, Wolf; Buchholz, Heino

1995-01-01

During the Higher Harmonic Control Aeroacoustic Rotor Test, extensive measurements of the rotor aerodynamics, the far-field acoustics, the wake geometry, and the blade motion for powered, descent, flight conditions were made. These measurements have been used to validate and improve the prediction of blade-vortex interaction (BVI) noise. The improvements made to the BVI modeling after the evaluation of the test data are discussed. The effects of these improvements on the acoustic-pressure predictions are shown. These improvements include restructuring the wake, modifying the core size, incorporating the measured blade motion into the calculations, and attempting to improve the dynamic blade response. A comparison of four different implementations of the Ffowcs Williams and Hawkings equation is presented. A common set of aerodynamic input has been used for this comparison.

Woodstove emission measurement methods: Comparison and emission factors update

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCrillis, R.C.; Jaasma, D.R.

1993-01-01

Since woodstoves are tested for certification in the laboratory using EPA Methods 5G and 5H, it is of interest to determine the correlation between these regulatory methods and the inhouse equipment. Two inhouse sampling systems have been used mostwidely: one is an intermittent, pump-driven particulate sampler that collects particulate and condensible organics on a filter and organic adsorbent resin; and the other uses an evacuated cylinder as the motive force and particulate and condensible organics are collected in a condenser and dual filter. Both samplers can operate unattended for 1-week periods. A large number of tests have been run comparingmore » Methods 5G and 5H to both samplers. The paper presents these comparison data and determines the relationships between regulations and field samplers.« less

IShTAR ICRF antenna field characterization in vacuum and plasma by using probe diagnostic

NASA Astrophysics Data System (ADS)

Usoltceva, Mariia; Ochoukov, Roman; D'Inca, Rodolphe; Jacquot, Jonathan; Crombé, Kristel; Kostic, Ana; Heuraux, Stéphane; Faudot, Eric; Noterdaeme, Jean-Marie

2017-10-01

RF sheath physics is one of the key topics relevant for improvements of ICRF heating systems, which are present on nearly all modern magnetic fusion machines. This paper introduces developement and validation of a new approach to understanding general RF sheath physics. The presumed reason of enhanced plasma-antenna interactions, parallel electric field, is not measured directly, but proposed to be obtained from simulations in COMSOL Multiphysics® Modeling Software. Measurements of RF magnetic field components with B-dot probes are done on a linear device IShTAR (Ion cyclotron Sheath Test ARrangement) and then compared to simulations. Good resulting accordance is suggested to be the criterion for trustworthiness of parallel electric field estimation as a component of electromagnetic field in modeling. A comparison between simulation and experiment for one magnetic field component in vacuum has demonstrated a close match. An additional complication to this ICRF antenna field characterization study is imposed by the helicon antenna which is used as a plasma ignition tool in the test arrangement. The plasma case, in contrast to the vacuum case, must be approached carefully, since the overlapping of ICRF antenna and helicon antenna fields occurs. Distinguishing of the two fields is done by an analysis of correlation between measurements with both antennas together and with each one separately.

Microwave Radiometer Observations of Snowpack Properties and Comparison of U.S. Japanese Results. [Hokkaido, Japan and Vermont and North Dakota test sites

NASA Technical Reports Server (NTRS)

Chang, A. T. C.

1985-01-01

Microwave data collected by field experiments over Vermont and Hokkaido and Nimbus-7 SMMR over North Dakota and Hokkaido were studied. The measured 37 GHz brightness temperatures show considerable effect of volume scattering by snow grains. The 37 GHz brightness for a new snowpack with average grain radius of 0.25 mm is generally about 40 K higher than the naturally compacted pack with average grain radius of 0.4 mm. The scattering effect is much less distinct for the 6.6 GHz. However, the layering effect is much stronger at the longer wavelength. For 10.7 and 18 GHz, the effect of layering and scattering vary due to different combinations of internal snow grain distribution and layering structures. Over the Hokkaido test site, the SMMR data are too coarse for the snow field. A better spatial resolution is required to study these snow fields.

Experimental vibroacoustic testing of plane panels using synthesized random pressure fields.

PubMed

Robin, Olivier; Berry, Alain; Moreau, Stéphane

2014-06-01

The experimental reproduction of random pressure fields on a plane panel and corresponding induced vibrations is studied. An open-loop reproduction strategy is proposed that uses the synthetic array concept, for which a small array element is moved to create a large array by post-processing. Three possible approaches are suggested to define the complex amplitudes to be imposed to the reproduction sources distributed on a virtual plane facing the panel to be tested. Using a single acoustic monopole, a scanning laser vibrometer and a baffled simply supported aluminum panel, experimental vibroacoustic indicators such as the Transmission Loss for Diffuse Acoustic Field, high-speed subsonic and supersonic Turbulent Boundary Layer excitations are obtained. Comparisons with simulation results obtained using a commercial software show that the Transmission Loss estimation is possible under both excitations. Moreover and as a complement to frequency domain indicators, the vibroacoustic behavior of the panel can be studied in the wave number domain.

International Symposium on Electromagnetic Compatibility, 25th, Arlington, VA, August 23-25, 1983, Symposium Record

NASA Astrophysics Data System (ADS)

Subjects related to electromagnetic compatibility (EMC) analysis are discussed, taking into account forcing terms of line equations for externally excited transmission lines, E-fields over ground, electromagnetic near fields as a function of electrical size, a program for experimental verification of EMC analysis models, random susceptability of an IC 7400 TTL NAND gate, and a comparison of IEMCAP and SEMCAP. Other topics explored are concerned with EMC measurements, spectrum management, the electromagnetic pulse (EMP), a Navy EMC program, measurement systems, filters, EMC design, electromagnetic vulnerability (EMV) assessment of weapon systems, FCC rules and regulations, shielding, and electromagnetic interference (EMI) in communication systems. Attention is also given to nonsinusoidal functions in radar and communications, transients/electrostatic discharge, open field testing, cables and connectors, interference effects of induced and conducted earth current at dc and ELF, test cells, and cable coupling.

A genuinely discontinuous approach for multiphase EHD problems

NASA Astrophysics Data System (ADS)

Natarajan, Mahesh; Desjardins, Olivier

2017-11-01

Electrohydrodynamics (EHD) involves solving the Poisson equation for the electric field potential. For multiphase flows, although the electric field potential is a continuous quantity, due to the discontinuity in the electric permittivity between the phases, additional jump conditions at the interface, for the normal and tangential components of the electric field need to be satisfied. All approaches till date either ignore the jump conditions, or involve simplifying assumptions, and hence yield unconvincing results even for simple test problems. In the present work, we develop a genuinely discontinuous approach for the Poisson equation for multiphase flows using a Finite Volume Unsplit Volume of Fluid method. The governing equation and the jump conditions without assumptions are used to develop the method, and its efficiency is demonstrated by comparison of the numerical results with canonical test problems having exact solutions. Postdoctoral Associate, Department of Mechanical and Aerospace Engineering.

Evaluation of commercial and field-expedient baited traps for house flies, Musca domestica L. (Diptera: Muscidae).

USDA-ARS?s Scientific Manuscript database

A comparison of 9 commercial baited fly traps on Florida dairy farms demonstrated that Terminator traps collected significantly more (13,323/trap) house flies (Musca domestica L.) than the others tested; Final Flight, Fly Magnet and FliesBeGone traps collected intermediate numbers of flies (834-2,16...

Comparison of synthetic food-based lures and liquid protein baits for capture of Anastrepha suspensa (Diptera: Tephritidae) adults

USDA-ARS?s Scientific Manuscript database

Field tests that were conducted in south Florida to compare capture of the Caribbean fruit fly, Anastrepha suspensa (Loew), in Multilure traps baited with liquid protein baits torula yeast/borax or NuLure/borax, or with food-based synthetic lures including two component (ammonium acetate, putrescine...

Analysis of remote sensing data for evaluating vegetation resources

NASA Technical Reports Server (NTRS)

1971-01-01

Increased utilization studies for current remote sensor and analysis capabilities included: (1) a review of testing procedures for quantifying the accuracy of photointerpretation; (2) field tests of a fully portable spectral data gathering system, both on the ground and from a helicopter; and (3) a comparison of three methods for obtaining ground information necessary for regional agricultural inventories. A version of the LARS point-by-point classification system was upgraded by the addition of routines to analyze spatial data information.

Natural pixel decomposition for computational tomographic reconstruction from interferometric projection: algorithms and comparison

NASA Astrophysics Data System (ADS)

Cha, Don J.; Cha, Soyoung S.

1995-09-01

A computational tomographic technique, termed the variable grid method (VGM), has been developed for improving interferometric reconstruction of flow fields under ill-posed data conditions of restricted scanning and incomplete projection. The technique is based on natural pixel decomposition, that is, division of a field into variable grid elements. The performances of two algorithms, that is, original and revised versions, are compared to investigate the effects of the data redundancy criteria and seed element forming schemes. Tests of the VGMs are conducted through computer simulation of experiments and reconstruction of fields with a limited view angel of 90 degree(s). The temperature fields at two horizontal sections of a thermal plume of two interacting isothermal cubes, produced by a finite numerical code, are analyzed as test fields. The computer simulation demonstrates the superiority of the revised VGM to either the conventional fixed grid method or the original VGM. Both the maximum and average reconstruction errors are reduced appreciably. The reconstruction shows substantial improvement in the regions with dense scanning by probing rays. These regions are usually of interest in engineering applications.

Helicopter rotor rotational noise predictions based on measured high-frequency blade loads

NASA Technical Reports Server (NTRS)

Hosier, R. N.; Ramakrishnan, R.

1974-01-01

In tests conducted at the Langley helicopter rotor test facility, simultaneous measurements of up to 200 harmonics of the fluctuating aerodynamic blade surface pressures and far-field radiated noise were made on a full-scale nontranslating rotor system. After their characteristics were determined, the measured blade surface pressures were converted to loading coefficients and used in an existing theory to predict the far-field rotational noise. A comparison of the calculated and measured noise shows generally good agreement up to 300 to 600 Hz, depending on the discreteness of the loading spectrum. Specific attention is given to the effects of the blade loading coefficients, chordwise loading distributions, blade loading phases, and observer azimuthal position on the calculations.

Field comparison of several commercially available radon detectors.

PubMed Central

Field, R W; Kross, B C

1990-01-01

To determine the accuracy and precision of commercially available radon detectors in a field setting, 15 detectors from six companies were exposed to radon and compared to a reference radon level. The detectors from companies that had already passed National Radon Measurement Proficiency Program testing had better precision and accuracy than those detectors awaiting proficiency testing. Charcoal adsorption detectors and diffusion barrier charcoal adsorption detectors performed very well, and the latter detectors displayed excellent time averaging ability. Alternatively, charcoal liquid scintillation detectors exhibited acceptable accuracy but poor precision, and bare alpha registration detectors showed both poor accuracy and precision. The mean radon level reported by the bare alpha registration detectors was 68 percent lower than the radon reference level. PMID:2368851

A Comparison of the AVS-9 and the Panoramic Night Vision Goggles During Rotorcraft Hover and Landing

NASA Technical Reports Server (NTRS)

Szoboszlay, Zoltan; Haworth, Loran; Simpson, Carol

2000-01-01

A flight test was conducted to assess any differences in pilot-vehicle performance and pilot opinion between the use of a current generation night vision goggle (the AVS-9) and one variant of the prototype panoramic night vision goggle (the PNVGII). The panoramic goggle has more than double the horizontal field-of-view of the AVS-9, but reduced image quality. Overall the panoramic goggles compared well to the AVS-9 goggles. However, pilot comment and data are consistent with the assertion that some of the benefits of additional field-of-view with the panoramic goggles were negated by the reduced image quality of the particular variant of the panoramic goggles tested.

Thermal Performance of Cryogenic Piping Multilayer Insulation in Actual Field Installations

NASA Technical Reports Server (NTRS)

Fesmire, J.; Augustnynowicz, S.; Thompson, K. (Technical Monitor)

2002-01-01

A standardized way of comparing the thermal performance of different pipelines in different sizes is needed. Vendor data for vacuum-insulated piping are typically given in heat leak rate per unit length (W/m) for a specific diameter pipeline. An overall k-value for actual field installations (k(sub oafi)) is therefore proposed as a more generalized measure for thermal performance comparison and design calculation. The k(sub oafi) provides a direct correspondence to the k-values reported for insulation materials and illustrates the large difference between ideal multilayer insulation (MLI) and actual MLI performance. In this experimental research study, a section of insulated piping was tested under cryogenic vacuum conditions, including simulated spacers and bending. Several different insulation systems were tested using a 1-meter-long cylindrical cryostat test apparatus. The simulated spacers tests showed significant degradation in the thermal performance of a given insulation system. An 18-meter-long pipeline test apparatus is now in operation at the Cryogenics Test Laboratory, NASA Kennedy Space Center, for conducting liquid nitrogen thermal performance tests.

CFD Simulations of the IHF Arc-Jet Flow: Compression-Pad Separation Bolt Wedge Tests

NASA Technical Reports Server (NTRS)

Gokcen, Tahir; Skokova, Kristina A.

2017-01-01

This paper reports computational analyses in support of two wedge tests in a high enthalpy arc-jet facility at NASA Ames Research Center. These tests were conducted using two different wedge models, each placed in a free jet downstream of a corresponding different conical nozzle in the Ames 60-MW Interaction Heating Facility. Each panel test article included a metallic separation bolt imbedded in Orion compression-pad and heatshield materials, resulting in a circular protuberance over a flat plate. The protuberances produce complex model flowfields, containing shock-shock and shock-boundary layer interactions, and multiple augmented heating regions on the test plate. As part of the test calibration runs, surface pressure and heat flux measurements on water-cooled calibration plates integrated with the wedge models were also obtained. Surface heating distributions on the test articles as well as arc-jet test environment parameters for each test configuration are obtained through computational fluid dynamics simulations, consistent with the facility and calibration measurements. The present analysis comprises simulations of the non-equilibrium flow field in the facility nozzle, test box, and flow field over test articles, and comparisons with the measured calibration data.

Testing of Visual Field with Virtual Reality Goggles in Manual and Visual Grasp Modes

PubMed Central

Wroblewski, Dariusz; Francis, Brian A.; Sadun, Alfredo; Vakili, Ghazal; Chopra, Vikas

2014-01-01

Automated perimetry is used for the assessment of visual function in a variety of ophthalmic and neurologic diseases. We report development and clinical testing of a compact, head-mounted, and eye-tracking perimeter (VirtualEye) that provides a more comfortable test environment than the standard instrumentation. VirtualEye performs the equivalent of a full threshold 24-2 visual field in two modes: (1) manual, with patient response registered with a mouse click, and (2) visual grasp, where the eye tracker senses change in gaze direction as evidence of target acquisition. 59 patients successfully completed the test in manual mode and 40 in visual grasp mode, with 59 undergoing the standard Humphrey field analyzer (HFA) testing. Large visual field defects were reliably detected by VirtualEye. Point-by-point comparison between the results obtained with the different modalities indicates: (1) minimal systematic differences between measurements taken in visual grasp and manual modes, (2) the average standard deviation of the difference distributions of about 5 dB, and (3) a systematic shift (of 4–6 dB) to lower sensitivities for VirtualEye device, observed mostly in high dB range. The usability survey suggested patients' acceptance of the head-mounted device. The study appears to validate the concepts of a head-mounted perimeter and the visual grasp mode. PMID:25050326

Comparisons of the Standard Galaxy Model with observations in two fields

NASA Technical Reports Server (NTRS)

Bahcall, J. N.; Ratnatunga, K. U.

1985-01-01

The Bahcall-Soneira (1984) model for the distribution of stars in the Galaxy is compared with the observations reported by Gilmore, Reid, and Hewett (1984) in two directions in the sky, the pole and the Morton-Tritton (1982) region. It is shown that the Galaxy model is in good agreement with the observations everywhere it has been tested with modern data, including the magnitude range, V = 17-18, and provided that the globular cluster feature is included in the luminosity function of the field Population II stars.

Effectiveness of Natural Field Induced Polarization for Detecting Polymetallic Deposits

NASA Astrophysics Data System (ADS)

YANG, Jin; LIU, Zhaoping; WANG, Long

To validate the effect of Natural Field Induced Polarization (NFIP), a certain polymetallic deposit was chosen as the test site, where Induced Polarization (IP) using gradient array and the Magnetotelluric (MT) sounding were conducted simultaneously. Analysis and comparison of the data indicated that the anomaly of the Relative Percent Frequency Effect (RPFE) from the MT data and the anomaly of IP coincided well with each other in the extents of the anomalous site and anomaly magnitudes. The results showed that NFIP was effective in the exploration of polymetallic deposits, under certain conditions.

Comparison of experimental and theoretical reaction rail currents, rail voltages, and airgap fields for the linear induction motor research vehicle

NASA Technical Reports Server (NTRS)

Elliott, D. G.

1977-01-01

Measurements of reaction rail currents, reaction rail voltages, and airgap magnetic fields in tests of the Linear Induction Motor Research Vehicle (LIMRV) were compared with theoretical calculations from the mesh/matrix theory. It was found that the rail currents and magnetic fields predicted by the theory are within 20 percent of the measured currents and fields at most motor locations in most of the runs, but differ by as much as a factor of two in some cases. The most consistent difference is a higher experimental than theoretical magnetic field near the entrance of the motor and a lower experimental than theoretical magnetic field near the exit. The observed differences between the theoretical and experimental magnetic fields and currents do not account for the differences of as much as 26 percent between the theoretical and experimental thrusts.

Numerical Modeling of Propellant Boiloff in Cryogenic Storage Tank

NASA Technical Reports Server (NTRS)

Majumdar, A. K.; Steadman, T. E.; Maroney, J. L.

2007-01-01

This Technical Memorandum (TM) describes the thermal modeling effort undertaken at Marshall Space Flight Center to support the Cryogenic Test Laboratory at Kennedy Space Center (KSC) for a study of insulation materials for cryogenic tanks in order to reduce propellant boiloff during long-term storage. The Generalized Fluid System Simulation program has been used to model boiloff in 1,000-L demonstration tanks built for testing the thermal performance of glass bubbles and perlite insulation. Numerical predictions of boiloff rate and ullage temperature have been compared with the measured data from the testing of demonstration tanks. A satisfactory comparison between measured and predicted data has been observed for both liquid nitrogen and hydrogen tests. Based on the experience gained with the modeling of the demonstration tanks, a numerical model of the liquid hydrogen storage tank at launch complex 39 at KSC was built. The predicted boiloff rate of hydrogen has been found to be in good agreement with observed field data. This TM describes three different models that have been developed during this period of study (March 2005 to June 2006), comparisons with test data, and results of parametric studies.

Neophobia in spontaneous hypertensive (SHR) and normotensive control (WKY) rats.

PubMed

Delini-Stula, A; Hunn, C

1985-03-01

Latency of approaching a novel object (white-colored cube) placed in an unfamiliar open field, duration of object exploration, ambulation, rearing, grooming, and defecation were investigated in spontaneous hypertensive rats (SHR), their genetic normotensive controls (WKY), and standard Laboratory rats of Wistar origin (Tif:RAIf). The parameters measured were taken as indices of fear due to novelty (neophobia). Remarkable differences in behavior of all three strains were observed. By comparison to RAIf and WKY rats, SHR showed decreased neophobia as reflected in the significantly shorter latency of approaching the object and enhanced ambulation and rearing activity in the open field. By comparison to RAIf rats SHR also showed reduced grooming and defecation. WKY rats distinguished themselves from both SHR and RAIf by almost total absence of all responses in this test situation. This behavioral suppression was antagonized by 7.5 mg/kg ip of chlordiazepoxide. The results of this study further support the notion that, by comparison to standard laboratory rats, both SHR and WKY rats show possible genetically determined, altered behaviors which are diametrically opposite to each other.

A Comparison of the Unpressurized Rover and Small Pressurized Rover During a Desert Field Evaluation

NASA Technical Reports Server (NTRS)

Litaker, Harry; Thompson, Shelby; Howard, Robert

2009-01-01

To effectively explore the lunar surface, astronauts will need a transportation vehicle which can traverse all types of terrain. Currently, the National Aeronautics and Space Administration s (NASA) is investigating two lunar rover configurations to meet such a requirement. Under the Lunar Electric Rover (LER) project, a comparison study between the unpressurized rover (UPR) and the small pressurized rover (SPR) was conducted at the Black Point Lava Flow in Arizona. The objective of the study was to obtain human-in-the-loop performance data on the vehicles with respect to human-machine interfaces, vehicle impacts on crew productivity, and scientific observations. Four male participants took part in four, one-day field tests using the exact same terrain and scientific sites for an accurate comparison between vehicle configurations. Subjective data was collected using several human factors performance measures. Results indicate either vehicle configuration was generally acceptable for a lunar mission; however, the SPR configuration was preferred over the UPR configuration primarily for the SPR s ability to cause less fatigue and enabling greater crew productivity.

Mobile lidar system for monitoring of gaseous pollutants in atmosphere over industrial and urban area

NASA Astrophysics Data System (ADS)

Moskalenko, Irina V.; Shecheglov, Djolinard A.; Rogachev, Aleksei P.; Avdonin, Aleksandr A.; Molodtsov, Nikolai A.

1999-01-01

The lidar remote sensing techniques are powerful for monitoring of gaseous toxic species in atmosphere over wide areas. The paper presented describes design, development and field testing of Mobile Lidar System (MLS) based on utilization of Differential Absorption Lidar (DIAL) technique. The activity is performed by Russian Research Center 'Kurchatov Institute' and Research Institute of Pulse Technique within the project 'Mobile Remote SEnsing System Based on Tunable Laser Transmitter for Environmental Monitoring' under funding of International Scientific and Technology Center Moscow. A brief description of MLS is presented including narrowband transmitter, receiver, system steering, data acquisition subsystem and software. MLS is housed in a mobile truck and is able to provide 3D mapping of gaseous species. Sulfur dioxide and elemental mercury were chosen as basic atmospheric pollutants for field test of MLS. The problem of anthropogenic ozone detection attracts attention due to increase traffic in Moscow. The experimental sites for field testing are located in Moscow Region. Examples of field DIAL measurements will be presented. Application of remote sensing to toxic species near-real time measurements is now under consideration. The objective is comparison of pollution level in working zone with maximum permissible concentration of hazardous pollutant.

Antigenic and genetic comparison of foot-and-mouth disease virus serotype O Indian vaccine strain, O/IND/R2/75 against currently circulating viruses.

PubMed

Mahapatra, Mana; Yuvaraj, S; Madhanmohan, M; Subramaniam, S; Pattnaik, B; Paton, D J; Srinivasan, V A; Parida, Satya

2015-01-29

Foot-and-mouth disease (FMD) virus serotype O is the most common cause of FMD outbreaks in India and three of the six lineages that have been described are most frequently detected, namely Ind2001, PanAsia and PanAsia 2. We report the full capsid sequence of 21 serotype O viruses isolated from India between 2002 and 2012. All these viruses belong to the Middle East-South Asia (ME-SA) topotype. The serological cross-reactivity of a bovine post-vaccination serum pool raised against the current Indian vaccine strain, O/IND/R2/75,was tested by virus neutralisation test with the 23 Indian field isolates, revealing a good match between the vaccine and the field isolates. The cross reactivity of the O/IND/R2/75 vaccine with 19 field isolates from other countries (mainly from Asia and Africa) revealed a good match to 79% of the viruses indicating that the vaccine strain is broadly cross-reactive and could be used to control FMD in other countries. Comparison of the capsid sequences of the serologically non-matching isolates with the vaccine strain sequence identified substitutions in neutralising antigenic sites 1 and 2, which could explain the observed serological differences. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Concentration Measurements in a Cold Flow Model Annular Combustor Using Laser Induced Fluorescence

NASA Technical Reports Server (NTRS)

Morgan, Douglas C.

1996-01-01

A nonintrusive concentration measurement method is developed for determining the concentration distribution in a complex flow field. The measurement method consists of marking a liquid flow with a water soluble fluorescent dye. The dye is excited by a two dimensional sheet of laser light. The fluorescent intensity is shown to be proportional to the relative concentration level. The fluorescent field is recorded on a video cassette recorder through a video camera. The recorded images are analyzed with image processing hardware and software to obtain intensity levels. Mean and root mean square (rms) values are calculated from these intensity levels. The method is tested on a single round turbulent jet because previous concentration measurements have been made on this configuration by other investigators. The previous results were used to comparison to qualify the current method. These comparisons showed that this method provides satisfactory results. 'Me concentration measurement system was used to measure the concentrations in the complex flow field of a model gas turbine annular combustor. The model annular combustor consists of opposing primary jets and an annular jet which discharges perpendicular to the primary jets. The mixing between the different jet flows can be visualized from the calculated mean and rms profiles. Concentration field visualization images obtained from the processing provide further qualitative information about the flow field.

SFDT-1 Camera Pointing and Sun-Exposure Analysis and Flight Performance

NASA Technical Reports Server (NTRS)

White, Joseph; Dutta, Soumyo; Striepe, Scott

2015-01-01

The Supersonic Flight Dynamics Test (SFDT) vehicle was developed to advance and test technologies of NASA's Low Density Supersonic Decelerator (LDSD) Technology Demonstration Mission. The first flight test (SFDT-1) occurred on June 28, 2014. In order to optimize the usefulness of the camera data, analysis was performed to optimize parachute visibility in the camera field of view during deployment and inflation and to determine the probability of sun-exposure issues with the cameras given the vehicle heading and launch time. This paper documents the analysis, results and comparison with flight video of SFDT-1.

The Multidimensional Assessment of Interoceptive Awareness (MAIA)

PubMed Central

Mehling, Wolf E.; Price, Cynthia; Daubenmier, Jennifer J.; Acree, Mike; Bartmess, Elizabeth; Stewart, Anita

2012-01-01

This paper describes the development of a multidimensional self-report measure of interoceptive body awareness. The systematic mixed-methods process involved reviewing the current literature, specifying a multidimensional conceptual framework, evaluating prior instruments, developing items, and analyzing focus group responses to scale items by instructors and patients of body awareness-enhancing therapies. Following refinement by cognitive testing, items were field-tested in students and instructors of mind-body approaches. Final item selection was achieved by submitting the field test data to an iterative process using multiple validation methods, including exploratory cluster and confirmatory factor analyses, comparison between known groups, and correlations with established measures of related constructs. The resulting 32-item multidimensional instrument assesses eight concepts. The psychometric properties of these final scales suggest that the Multidimensional Assessment of Interoceptive Awareness (MAIA) may serve as a starting point for research and further collaborative refinement. PMID:23133619

Acoustic test and analyses of three advanced turboprop models

NASA Technical Reports Server (NTRS)

Brooks, B. M.; Metzger, F. B.

1980-01-01

Results of acoustic tests of three 62.2 cm (24.5 inch) diameter models of the prop-fan (a small diameter, highly loaded. Multi-bladed variable pitch advanced turboprop) are presented. Results show that there is little difference in the noise produced by unswept and slightly swept designs. However, the model designed for noise reduction produces substantially less noise at test conditions simulating 0.8 Mach number cruise speed or at conditions simulating takeoff and landing. In the near field at cruise conditions the acoustically designed. In the far field at takeoff and landing conditions the acoustically designed model is 5 db quieter than unswept or slightly swept designs. Correlation between noise measurement and theoretical predictions as well as comparisons between measured and predicted acoustic pressure pulses generated by the prop-fan blades are discussed. The general characteristics of the pulses are predicted. Shadowgraph measurements were obtained which showed the location of bow and trailing waves.

Near-field measurement facility plans at Lewis Research Center

NASA Technical Reports Server (NTRS)

Sharp, R. G.

1983-01-01

The direction of future antenna technology will be toward antennas which are large, both physically and electrically, will operate at frequencies up to 60 GHz, and are non-reciprocal and complex, implementing multiple-beam and scanning beam concepts and monolithic semiconductor devices and techniques. The acquisition of accurate antenna performance measurements is a critical part of the advanced antenna research program and represents a substantial antenna measurement technology challenge, considering the special characteristics of future spacecraft communications antennas. Comparison of various antenna testing techniques and their relative advantages and disadvantages shows that the near-field approach is necessary to meet immediate and long-term testing requirements. The LeRC facilities, the 22 ft x 22 ft horizontal antenna boresight planar scanner and the 60 ft x 60 ft vertical antenna boresight plant scanner (with a 60 GHz frequency and D/lamdba = 3000 electrical size capabilities), will meet future program testing requirements.

Effects of dried wastewater-treatment sludge application on ground-water quality in South Dade County, Florida

USGS Publications Warehouse

Howie, Barbara

1992-01-01

Four test fields in the south Dade agricultural area were studied to determine the effects of sludge application on ground-water quality. Two fields had been cultivated for 10 years or more, and two had not been farmed for at least 10 years. The fields were representative of the area's two soil types (Rockdale and Perrine marl) and two major crop types (row crops and groves). Before the application of sludge, wells upgradient of, within, and downgradient of each field were sampled for possible sludge contaminants at the end of wet and dry seasons. Municipal wastewater treatment sludge from the Dade County Water and Sewe Authority Department was then applied to the fields at varying application rates. The wells at each field were sampled over a 2-year period under different hydrologic conditions for possible sludge-related constituents (specific conductance, pH, alkalinity, nitrogen, phosphorus, total organic carbon, copper, iron, magnesium, manganese, potassium, zinc, arsenic, cadmium, chloride, chromium, lead, mercury, nickel, and sodium). Comparisons were made between water quality in the vicinity of the test fields and Florida Department of Environmental Regulation primary and secondary drinking-water regulations, an between water quality upgradient of, beneath, and downgradient of the fields. Comparisons between presludge and postsludge water quality did not indicate any improvement because of retention of agrichemicals by the sludge nor did they indicate any deterioration because of leaching from the sludge. Comparisons of water quality upgradient of the fields to water quality beneath and downgradient of the fields also did not indicate any changes related to sludge. Florida Department of Environmental Regulation primary and secondary drinking-water regulations wer exceeded at the Rockdale maximum-application field by mercury (9.5 ug/L (micrograms per liter)), and the Perrine marl maximum-application field by manganese (60 ug/L) and lead (85 ug/L), and at the Perrine marl row-crop field by mercury (5.2 ug/L). All other exceedances were either in presludge or upgradient samples, or they were for constituents or properties, such as iron and color, which typically exceed standards in native ground water. Acid-extractable and base-neutral compounds, volatile organic compounds, chlorophenoxy herbicides, organophosphorus insecticides, and organochlorine compounds were analyzed for one shallow well at each field twice annually. Those compounds that equaled or exceeded the detection limit after sludge was applied included benzene (0.3 and 1.2 ug/L), chloroform (0.2 and 0.3 ug/L), bis(2-Ethylhexyl)phthalate (29 and 42 ug/L), methylene chloride (14 ug/L), tolulene (0.2, 0.4, 0.5, 1.3, and 4.4 ug/L), 1, 1,1-trichloroethana (0.6 ug/L), trichloroethylene (0.3 ug/L), 2.4-D (0.01 ug/L), and xylene (0.3 ug/L). It ws not possible to ascertain the origin of these compounds becuase they are available from sources other than sludge.

The Flow Dimension and Aquifer Heterogeneity: Field evidence and Numerical Analyses

NASA Astrophysics Data System (ADS)

Walker, D. D.; Cello, P. A.; Valocchi, A. J.; Roberts, R. M.; Loftis, B.

2008-12-01

The Generalized Radial Flow approach to hydraulic test interpretation infers the flow dimension to describe the geometry of the flow field during a hydraulic test. Noninteger values of the flow dimension often are inferred for tests in highly heterogeneous aquifers, yet subsequent modeling studies typically ignore the flow dimension. Monte Carlo analyses of detailed numerical models of aquifer tests examine the flow dimension for several stochastic models of heterogeneous transmissivity, T(x). These include multivariate lognormal, fractional Brownian motion, a site percolation network, and discrete linear features with lengths distributed as power-law. The behavior of the simulated flow dimensions are compared to the flow dimensions observed for multiple aquifer tests in a fractured dolomite aquifer in the Great Lakes region of North America. The combination of multiple hydraulic tests, observed fracture patterns, and the Monte Carlo results are used to screen models of heterogeneity and their parameters for subsequent groundwater flow modeling. The comparison shows that discrete linear features with lengths distributed as a power-law appear to be the most consistent with observations of the flow dimension in fractured dolomite aquifers.

NIST-NRC Comparison of Total Immersion Liquid-in-Glass Thermometers

NASA Astrophysics Data System (ADS)

Hill, K. D.; Gee, D. J.; Cross, C. D.; Strouse, G. F.

2009-02-01

The use of liquid-in-glass (LIG) thermometers is described in many documentary standards in the fields of environmental testing, material testing, and material transfer. Many national metrology institutes, including the National Institute of Standards and Technology (NIST) and the National Research Council of Canada (NRC), list calibration services for these thermometers among the Calibration Measurement Capabilities of Appendix C of the BIPM Key Comparison Database. NIST and NRC arranged a bilateral comparison of a set of total-immersion ASTM-type LIG thermometers to validate their uncertainty claims. Two each of ASTM thermometer types 62C through 69C were calibrated at NIST and at NRC at four temperatures distributed over the range appropriate to each thermometer, in addition to the ice point. Collectively, the thermometers span a temperature range of - 38 °C to 305 °C. In total, 160 measurements (80 pairs) comprise the comparison data set. Pair-wise differences ( T NIST- T NRC) were formed for each thermometer at each temperature. For 8 of the 80 pairs (10 %), the differences exceed the k = 2 combined uncertainties. These results support the claimed capabilities of NIST and NRC for the calibration of LIG thermometers.

A measurement of forward-flight effects on the noise from a JT15D-1 turbofan engine in the NASA-Ames 40- by 80-Foot Wind Tunnel

NASA Technical Reports Server (NTRS)

Ahtye, W. F.

1980-01-01

A Pratt and Whitney JT15D-1 turbofan engine was tested in two facilities at Ames Research Center: the outdoor Static Test Facility and the 40- by 80-Foot Wind Tunnel. The primary purposes of the test were to determine the effects of forward velocity on the turbofan spectra in the forward quadrant for the cruise inlet and to compare these wind-tunnel spectra with outdoor spectra to determine the possibility of simulating forward-velocity effects from purely outdoor measurements. The wind-tunnel data show a reduction in the blade-passage frequency tones of the order of 10 dB with increasing forward velocity at subsonic fan-tip speeds. No forward-velocity variation was observed at supersonic tip speeds. Comparison of in-duct spectra for the cruise inlet at forward velocity, with spectra from outdoor tests with a distortion-control inlet shows excellent agreement for the in-duct data when allowance is made for different in-duct volumes. This is also reflected in good agreement for the far-field spectra at small forward angles. The comparisons of wind-tunnel and outdoor data also indicate that at least for the JT15D-1, it may be possible to approximate the shape of the far-field spectra at large directivity angles from an outdoor measurement with the cruise inlet, providing an effective inflow control device is used.

A comparison of cheap talk and alternative certainty calibration techniques in contingent valuation

Treesearch

Mihail Samnaliev; Thomas Stevens; Thomas More

2003-01-01

A field test of cheap talk and two types of certainty calibration in contingent valuation of public lands indicated that cheap talk does not reduce WTP estimates. Use of a ten point certainty calibration scale reduces WTP estimates by about half. However, adjusting for uncertainty using a 'Not Sure' option does not reduce WTP estimates but increases the...

Results and comparison of Hall and DW duct experiments

NASA Technical Reports Server (NTRS)

Smith, J. M.; Morgan, J. L.

1982-01-01

Experimental data from recent tests of a 45 deg diagonal wall duct are presented and compared with the results of a similar Hall duct. It is shown that while the peak power density of the two devices is approximately equal that the diagonal wall duct produces greater total power output due to its ability to better utilize the available magnetic field.

Tests of bioaccumulation models for polychlorinated biphenyl compounds: a study of young-of-the-year bluefish in the Hudson River estuary, USA.

PubMed

Leblanc, Lawrence A; Buckel, Jeffrey A; Conover, David O; Brownawell, Bruce J

2006-08-01

A field-based study regarding uptake of polychlorinated biphenyl compounds (PCBs) by young-of-the-year (YOY) bluefish (Pomatomus saltatrix) was initiated to test a steady-state model of bioaccumulation and trophic transfer in a rapidly growing fish. Determination of prey composition as well as size-dependent growth and specific consumption rates for YOY bluefish from separate field and laboratory studies enabled the input of these species-specific parameters into the model. Furthermore, the time and duration of the exposure of YOY bluefish to dissolved PCBs from a well-characterized system (Hudson River, USA) was well known. Patterns of accumulation of individual PCB congeners differed relative to the accumulation of total PCBs, with the greatest net accumulation occurring for the higher-molecular-weight congeners. Comparison of lipid-normalized bioaccumulation factors (BAFs) with the octanol-water partition coefficients of individual PCB congeners revealed bluefish to be above the BAFs predicted by lipid-based equilibrium partitioning, suggesting that uptake from food is an important source of PCBs in YOY bluefish. Comparison of measured BAFs with values predicted by a steady-state, food-chain model showed good first-order agreement.

Comparing peak and submaximal cardiorespiratory responses during field walking tests with incremental cycle ergometry in COPD.

PubMed

Hill, Kylie; Dolmage, Thomas E; Woon, Lynda; Coutts, Debbie; Goldstein, Roger; Brooks, Dina

2012-02-01

Field and laboratory-based tests are used to measure exercise capacity in people with COPD. A comparison of the cardiorespiratory responses to field tests, referenced to a laboratory test, is needed to appreciate the relative physiological demands. We sought to compare peak and submaximal cardiorespiratory responses to the 6-min walk test, incremental shuttle walk test and endurance shuttle walk test with a ramp cycle ergometer test (CET) in patients with COPD. Twenty-four participants (FEV(1) 50 ± 14%; 66.5 ± 7.7 years; 15 men) completed four sessions, separated by ≥24 h. During an individual session, participants completed either two 6-min walk tests, incremental shuttle walk tests, endurance shuttle walk tests using standardized protocols, or a single CET, wearing a portable gas analysis unit (Cosmed K4b(2)) which included measures of heart rate and arterial oxygen saturation (SpO(2)). Between tests, no difference was observed in the peak rate of oxygen uptake (F(3,69) = 1.2; P = 0.31), end-test heart rate (F(2,50) = 0.6; P = 0.58) or tidal volume (F(3,69) = 1.5; P = 0.21). Compared with all walking tests, the CET elicited a higher peak rate of carbon dioxide output (1173 ± 350 mL/min; F(3,62) = 4.8; P = 0.006), minute ventilation (48 ± 17 L/min; F(3,69) = 10.2; P < 0.001) and a higher end-test SpO(2) (95 ± 4%; F(3,63) = 24.9; P < 0.001). In patients with moderate COPD, field walking tests elicited a similar peak rate of oxygen uptake and heart rate as a CET, demonstrating that both self- and externally paced walking tests progress to high intensities. © 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology.

Charged-particle motion in multidimensional magnetic-field turbulence

NASA Technical Reports Server (NTRS)

Giacalone, J.; Jokipii, J. R.

1994-01-01

We present a new analysis of the fundamental physics of charged-particle motion in a turbulent magnetic field using a numerical simulation. The magnetic field fluctuations are taken to be static and to have a power spectrum which is Kolmogorov. The charged particles are treated as test particles. It is shown that when the field turbulence is independent of one coordinate (i.e., k lies in a plane), the motion of these particles across the magnetic field is essentially zero, as required by theory. Consequently, the only motion across the average magnetic field direction that is allowed is that due to field-line random walk. On the other hand, when a fully three-dimensional realization of the turbulence is considered, the particles readily cross the field. Transport coefficients both along and across the ambient magnetic field are computed. This scheme provides a direct computation of the Fokker-Planck coefficients based on the motions of individual particles, and allows for comparison with analytic theory.

Comparison of culture versus quantitative real-time polymerase chain reaction for the detection of Taylorella equigenitalis in field samples from naturally infected horses in Canada and Germany.

PubMed

Nadin-Davis, Susan; Knowles, Margaret K; Burke, Teresa; Böse, Reinhard; Devenish, John

2015-07-01

A quantitative real-time polymerase chain reaction method (qPCR) was developed and tested for the detection of Taylorella equigenitalis. It was shown to have an analytical sensitivity of 5 colony-forming units (CFU) of T. equigenitalis when applied to the testing of culture swabs that mimicked field samples, and a high analytical specificity in not reacting to 8 other commensal bacterial species associated with horses. As designed, it could also differentiate specifically between T. equigenitalis and T. asinigenitalis. The qPCR was compared to standard culture in a study that included 45 swab samples from 6 horses (1 stallion, 5 mares) naturally infected with T. equigenitalis in Canada, 39 swab samples from 5 naturally infected stallions in Germany, and 311 swab samples from 87 culture negative horses in Canada. When the comparison was conducted on an individual sample swab basis, the qPCR had a statistical sensitivity and specificity of 100% and 96.4%, respectively, and 100% and 99.1% when the comparison was conducted on a sample set basis. A comparison was also made on 203 sample swabs from the 5 German stallions taken over a span of 4 to 9 mo following antibiotic treatment. The qPCR was found to be highly sensitive and at least as good as culture in detecting the presence of T. equigenitalis in post-treatment samples. The work demonstrates that the qPCR assay described here can potentially be used to detect the presence of T. equigenitalis directly from submitted sample swabs taken from infected horses and also for determining T. equigenitalis freedom following treatment.

Comparison of culture versus quantitative real-time polymerase chain reaction for the detection of Taylorella equigenitalis in field samples from naturally infected horses in Canada and Germany

PubMed Central

Nadin-Davis, Susan; Knowles, Margaret K.; Burke, Teresa; Böse, Reinhard; Devenish, John

2015-01-01

A quantitative real-time polymerase chain reaction method (qPCR) was developed and tested for the detection of Taylorella equigenitalis. It was shown to have an analytical sensitivity of 5 colony-forming units (CFU) of T. equigenitalis when applied to the testing of culture swabs that mimicked field samples, and a high analytical specificity in not reacting to 8 other commensal bacterial species associated with horses. As designed, it could also differentiate specifically between T. equigenitalis and T. asinigenitalis. The qPCR was compared to standard culture in a study that included 45 swab samples from 6 horses (1 stallion, 5 mares) naturally infected with T. equigenitalis in Canada, 39 swab samples from 5 naturally infected stallions in Germany, and 311 swab samples from 87 culture negative horses in Canada. When the comparison was conducted on an individual sample swab basis, the qPCR had a statistical sensitivity and specificity of 100% and 96.4%, respectively, and 100% and 99.1% when the comparison was conducted on a sample set basis. A comparison was also made on 203 sample swabs from the 5 German stallions taken over a span of 4 to 9 mo following antibiotic treatment. The qPCR was found to be highly sensitive and at least as good as culture in detecting the presence of T. equigenitalis in post-treatment samples. The work demonstrates that the qPCR assay described here can potentially be used to detect the presence of T. equigenitalis directly from submitted sample swabs taken from infected horses and also for determining T. equigenitalis freedom following treatment. PMID:26130847

Visual field progression in glaucoma: total versus pattern deviation analyses.

PubMed

Artes, Paul H; Nicolela, Marcelo T; LeBlanc, Raymond P; Chauhan, Balwantray C

2005-12-01

To compare visual field progression with total and pattern deviation analyses in a prospective longitudinal study of patients with glaucoma and healthy control subjects. A group of 101 patients with glaucoma (168 eyes) with early to moderately advanced visual field loss at baseline (average mean deviation [MD], -3.9 dB) and no clinical evidence of media opacity were selected from a prospective longitudinal study on visual field progression in glaucoma. Patients were examined with static automated perimetry at 6-month intervals for a median follow-up of 9 years. At each test location, change was established with event and trend analyses of total and pattern deviation. The event analyses compared each follow-up test to a baseline obtained from averaging the first two tests, and visual field progression was defined as deterioration beyond the 5th percentile of test-retest variability at three test locations, observed on three consecutive tests. The trend analyses were based on point-wise linear regression, and visual field progression was defined as statistically significant deterioration (P < 5%) worse than -1 dB/year at three locations, confirmed by independently omitting the last and the penultimate observation. The incidence and the time-to-progression were compared between total and pattern deviation analyses. To estimate the specificity of the progression analyses, identical criteria were applied to visual fields obtained in 102 healthy control subjects, and the rate of visual field improvement was established in the patients with glaucoma and the healthy control subjects. With both event and trend methods, pattern deviation analyses classified approximately 15% fewer eyes as having progressed than did the total deviation analyses. In eyes classified as progressing by both the total and pattern deviation methods, total deviation analyses tended to detect progression earlier than the pattern deviation analyses. A comparison of the changes observed in MD and the visual fields' general height (estimated by the 85th percentile of the total deviation values) confirmed that change in the glaucomatous eyes almost always comprised a diffuse component. Pattern deviation analyses of progression may therefore underestimate the true amount of glaucomatous visual field progression. Pattern deviation analyses of visual field progression may underestimate visual field progression in glaucoma, particularly when there is no clinical evidence of increasing media opacity. Clinicians should have access to both total and pattern deviation analyses to make informed decisions on visual field progression in glaucoma.

Development and Testing of a Smartphone-Based Cognitive/Neuropsychological Evaluation System for Substance Abusers.

PubMed

Pal, Reshmi; Mendelson, John; Clavier, Odile; Baggott, Mathew J; Coyle, Jeremy; Galloway, Gantt P

2016-01-01

In methamphetamine (MA) users, drug-induced neurocognitive deficits may help to determine treatment, monitor adherence, and predict relapse. To measure these relationships, we developed an iPhone app (Neurophone) to compare lab and field performance of N-Back, Stop Signal, and Stroop tasks that are sensitive to MA-induced deficits. Twenty healthy controls and 16 MA-dependent participants performed the tasks in-lab using a validated computerized platform and the Neurophone before taking the latter home and performing the tasks twice daily for two weeks. N-Back task: there were no clear differences in performance between computer-based vs. phone-based in-lab tests and phone-based in-lab vs. phone-based in-field tests. Stop-Signal task: difference in parameters prevented comparison of computer-based and phone-based versions. There was significant difference in phone performance between field and lab. Stroop task: response time measured by the speech recognition engine lacked precision to yield quantifiable results. There was no learning effect over time. On an average, each participant completed 84.3% of the in-field NBack tasks and 90.4% of the in-field Stop Signal tasks (MA-dependent participants: 74.8% and 84.3%; healthy controls: 91.4% and 95.0%, respectively). Participants rated Neurophone easy to use. Cognitive tasks performed in-field using Neurophone have the potential to yield results comparable to those obtained in a laboratory setting. Tasks need to be modified for use as the app's voice recognition system is not yet adequate for timed tests.

Structure-function relationships using spectral-domain optical coherence tomography: comparison with scanning laser polarimetry.

PubMed

Aptel, Florent; Sayous, Romain; Fortoul, Vincent; Beccat, Sylvain; Denis, Philippe

2010-12-01

To evaluate and compare the regional relationships between visual field sensitivity and retinal nerve fiber layer (RNFL) thickness as measured by spectral-domain optical coherence tomography (OCT) and scanning laser polarimetry. Prospective cross-sectional study. One hundred and twenty eyes of 120 patients (40 with healthy eyes, 40 with suspected glaucoma, and 40 with glaucoma) were tested on Cirrus-OCT, GDx VCC, and standard automated perimetry. Raw data on RNFL thickness were extracted for 256 peripapillary sectors of 1.40625 degrees each for the OCT measurement ellipse and 64 peripapillary sectors of 5.625 degrees each for the GDx VCC measurement ellipse. Correlations between peripapillary RNFL thickness in 6 sectors and visual field sensitivity in the 6 corresponding areas were evaluated using linear and logarithmic regression analysis. Receiver operating curve areas were calculated for each instrument. With spectral-domain OCT, the correlations (r(2)) between RNFL thickness and visual field sensitivity ranged from 0.082 (nasal RNFL and corresponding visual field area, linear regression) to 0.726 (supratemporal RNFL and corresponding visual field area, logarithmic regression). By comparison, with GDx-VCC, the correlations ranged from 0.062 (temporal RNFL and corresponding visual field area, linear regression) to 0.362 (supratemporal RNFL and corresponding visual field area, logarithmic regression). In pairwise comparisons, these structure-function correlations were generally stronger with spectral-domain OCT than with GDx VCC and with logarithmic regression than with linear regression. The largest areas under the receiver operating curve were seen for OCT superior thickness (0.963 ± 0.022; P < .001) in eyes with glaucoma and for OCT average thickness (0.888 ± 0.072; P < .001) in eyes with suspected glaucoma. The structure-function relationship was significantly stronger with spectral-domain OCT than with scanning laser polarimetry, and was better expressed logarithmically than linearly. Measurements with these 2 instruments should not be considered to be interchangeable. Copyright © 2010 Elsevier Inc. All rights reserved.

Helicopter Blade-Vortex Interaction Noise with Comparisons to CFD Calculations

NASA Technical Reports Server (NTRS)

McCluer, Megan S.

1996-01-01

A comparison of experimental acoustics data and computational predictions was performed for a helicopter rotor blade interacting with a parallel vortex. The experiment was designed to examine the aerodynamics and acoustics of parallel Blade-Vortex Interaction (BVI) and was performed in the Ames Research Center (ARC) 80- by 120-Foot Subsonic Wind Tunnel. An independently generated vortex interacted with a small-scale, nonlifting helicopter rotor at the 180 deg azimuth angle to create the interaction in a controlled environment. Computational Fluid Dynamics (CFD) was used to calculate near-field pressure time histories. The CFD code, called Transonic Unsteady Rotor Navier-Stokes (TURNS), was used to make comparisons with the acoustic pressure measurement at two microphone locations and several test conditions. The test conditions examined included hover tip Mach numbers of 0.6 and 0.7, advance ratio of 0.2, positive and negative vortex rotation, and the vortex passing above and below the rotor blade by 0.25 rotor chords. The results show that the CFD qualitatively predicts the acoustic characteristics very well, but quantitatively overpredicts the peak-to-peak sound pressure level by 15 percent in most cases. There also exists a discrepancy in the phasing (about 4 deg) of the BVI event in some cases. Additional calculations were performed to examine the effects of vortex strength, thickness, time accuracy, and directionality. This study validates the TURNS code for prediction of near-field acoustic pressures of controlled parallel BVI.

Woodstove smoke and CO emissions: comparison of reference methods with the VIP sampler.

PubMed

Jaasma, D R; Champion, M C; Shelton, J W

1990-06-01

A new field sampler has been developed for measuring the particulate matter (PM) and carbon monoxide emissions of woodburning stoves. Particulate matter is determined by carbon balance and the workup of a sample train which is similar to a room-temperature EPA Method 5G train. A steel tank, initially evacuated, serves as the motive force for sampling and also accumulates a gas sample for post-test analysis of time-averaged stack CO and CO2 concentrations. Workup procedures can be completed within 72 hours of sampler retrieval. The system has been compared to reference methods in two laboratory test series involving six different woodburning appliances and two independent laboratories. The correlation of field sampler emission rates and reference method rates is strong.

Woodstove smoke and CO emissions: Comparison of reference methods with the VIP sampler

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaasma, D.R.; Champion, M.C.; Shelton, J.W.

1990-06-01

A new field sampler has been developed for measuring the particulate matter (PM) and carbon monoxide emissions of woodburning stoves. Particulate matter is determined by carbon balance and the workup of a sample train which is similar to a room-temperature EPA Method 5G train. A steel tank, initially evacuated, serves as the motive force for sampling and also accumulates a gas sample for post-test analysis of time-averaged stack CO and CO{sub 2} concentrations. Workup procedures can be completed within 72 hours of sampler retrieval. The system has been compared to reference methods in two laboratory test series involving six differentmore » woodburning appliances and two independent laboratories. The correlation of field sampler emission rates and reference method rates is strong.« less

A preliminary comparison of Na lidar and meteor radar zonal winds during geomagnetic quiet and disturbed conditions

NASA Astrophysics Data System (ADS)

Kishore Kumar, G.; Nesse Tyssøy, H.; Williams, Bifford P.

2018-03-01

We investigate the possibility that sufficiently large electric fields and/or ionization during geomagnetic disturbed conditions may invalidate the assumptions applied in the retrieval of neutral horizontal winds from meteor and/or lidar measurements. As per our knowledge, the possible errors in the wind estimation have never been reported. In the present case study, we have been using co-located meteor radar and sodium resonance lidar zonal wind measurements over Andenes (69.27°N, 16.04°E) during intense substorms in the declining phase of the January 2005 solar proton event (21-22 January 2005). In total, 14 h of measurements are available for the comparison, which covers both quiet and disturbed conditions. For comparison, the lidar zonal wind measurements are averaged over the same time and altitude as the meteor radar wind measurements. High cross correlations (∼0.8) are found in all height regions. The discrepancies can be explained in light of differences in the observational volumes of the two instruments. Further, we extended the comparison to address the electric field and/or ionization impact on the neutral wind estimation. For the periods of low ionization, the neutral winds estimated with both instruments are quite consistent with each other. During periods of elevated ionization, comparatively large differences are noticed at the highermost altitude, which might be due to the electric field and/or ionization impact on the wind estimation. At present, one event is not sufficient to make any firm conclusion. Further study with more co-located measurements are needed to test the statistical significance of the result.

Representation of the visual field in the striate cortex: comparison of MR findings with visual field deficits in organic mercury poisoning (Minamata disease).

PubMed

Korogi, Y; Takahashi, M; Hirai, T; Ikushima, I; Kitajima, M; Sugahara, T; Shigematsu, Y; Okajima, T; Mukuno, K

1997-01-01

To compare MR imaging findings of the striate cortex with visual field deficits in patients with Minamata disease and to reestimate the classical Holmes retinotopic map by using the data obtained from comparing visual field abnormalities with degree of visual cortex atrophy. MR imaging was performed in eight patients with Minamata disease who had been given a full neuroophthalmic examination, including Goldmann dynamic perimetry. The atrophic portions of the calcarine area were measured in the sagittal plane next to the midsagittal image and represented as a percentage of atrophy of the total length of the calcarine fissure. MR findings were compared with results of a visual field test. The visual field test revealed moderate to severe concentric constriction of the visual fields, with central vision ranging from 7 degrees to 42 degrees (mean, 19 degrees). The ventral portion of the calcarine sulcus was significantly dilated on MR images in all patients. A logarithmic correlation was found between the visual field defect and the extent of dilatation of the calcarine fissure. The central 10 degrees and 30 degrees of vision seemed to fill about 20% and 50% of the total surface area of the calcarine cortex, respectively. Visual field deficits in patients with Minamata disease correlated well with MR findings of the striate cortex. Our data were consistent with the classical Holmes retinotopic map.

Measuring Extinction in Local Group Galaxies Using Background Galaxies

NASA Astrophysics Data System (ADS)

Wyder, T. K.; Hodge, P. W.

1999-05-01

Knowledge of the distribution and quantity of dust in galaxies is important for understanding their structure and evolution. The goal of our research is to measure the total extinction through Local Group galaxies using measured properties of background galaxies. Our method relies on the SExtractor software as an objective and automated method of detecting background galaxies. In an initial test, we have explored two WFPC2 fields in the SMC and two in M31 obtained from the HST archives. The two pointings in the SMC are fields around the open clusters L31 and B83 while the two M31 fields target the globular clusters G1 and G170. Except for the G1 observations of M31, the fields chosen are very crowded (even when observed with HST) and we chose them as a particularly stringent test of the method. We performed several experiments using a series of completeness tests that involved superimposing comparison fields, adjusted to the equivalent exposure time, from the HST Medium-Deep and Groth-Westphal surveys. These tests showed that for crowded fields, such as the two in the core of the SMC and the one in the bulge of M31, this automated method of detecting galaxies can be completely dominated by the effects of crowding. For these fields, only a small fraction of the added galaxies was recovered. However, in the outlying G1 field in M31, almost all of the added galaxies were recovered. The numbers of actual background galaxies in this field are consistent with zero extinction. As a follow-up experiment, we used image processing techniques to suppress stellar objects while enhancing objects with non-stellar, more gradual luminosity profiles. This method yielded significant numbers of background galaxies in even the most crowded fields, which we are now analyzing to determine the total extinction and reddening caused by the foreground galaxy.

Mechanical and wear characteristics of epoxy composites filled with industrial wastes: A comparative study

NASA Astrophysics Data System (ADS)

Purohit, A.; Satapathy, A.

2017-02-01

Use of industrial wastes, such as slag and sludge particles, as filler in polymers is not very common in the field of composite research. Therefore in this paper, a comparison of mechanical characteristics of epoxy based composites filled with LD sludge, BF slag and LD slag (wastes generated in iron and steel industries) were presented. A comparative study among these composites in regard to their dry sliding wear characteristics under similar test conditions was also included. Composites with different weight proportions (0, 5, 10, 15 and 20 wt.%) of LD sludge were fabricated by solution casting technique. Mechanical properties were evaluated as per ASTM test standards and sliding wear test was performed following a design of experiment approach based on Taguchi’s orthogonal array. The test results for epoxy-LD sludge composites were compared with those of epoxy-BF slag and epoxy-LD slag composites reported by previous investigators. The comparison reveals that epoxy filled with LD sludge exhibits superior mechanical and wear characteristics among the three types of composites considered in this study.

FAST Model Calibration and Validation of the OC5- DeepCwind Floating Offshore Wind System Against Wave Tank Test Data: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wendt, Fabian F; Robertson, Amy N; Jonkman, Jason

During the course of the Offshore Code Comparison Collaboration, Continued, with Correlation (OC5) project, which focused on the validation of numerical methods through comparison against tank test data, the authors created a numerical FAST model of the 1:50-scale DeepCwind semisubmersible system that was tested at the Maritime Research Institute Netherlands ocean basin in 2013. This paper discusses several model calibration studies that were conducted to identify model adjustments that improve the agreement between the numerical simulations and the experimental test data. These calibration studies cover wind-field-specific parameters (coherence, turbulence), hydrodynamic and aerodynamic modeling approaches, as well as rotor model (blade-pitchmore » and blade-mass imbalances) and tower model (structural tower damping coefficient) adjustments. These calibration studies were conducted based on relatively simple calibration load cases (wave only/wind only). The agreement between the final FAST model and experimental measurements is then assessed based on more-complex combined wind and wave validation cases.« less

Quiet engine program: Turbine noise suppression. -Volume 1: General treatment evaluation and measurement techniques

NASA Technical Reports Server (NTRS)

Clemons, A.; Hehmann, H.; Radecki, K.

1973-01-01

Acoustic treatment was developed for jet engine turbine noise suppression. Acoustic impedance and duct transmission loss measurements were made for various suppression systems. An environmental compatibility study on several material types having suppression characteristics is presented. Two sets of engine hardware were designed and are described along with engine test results which include probe, farfield, near field, and acoustic directional array data. Comparisons of the expected and the measured suppression levels are given as well as a discussion of test results and design techniques.

LAVA Simulations for the AIAA Sonic Boom Prediction Workshop

NASA Technical Reports Server (NTRS)

Housman, Jeffrey A.; Sozer, Emre; Moini-Yekta , Shayan; Kiris, Cetin C.

2014-01-01

Computational simulations using the Launch Ascent and Vehicle Aerodynamics (LAVA) framework are presented for the First AIAA Sonic Boom Prediction Workshop test cases. The framework is utilized with both structured overset and unstructured meshing approaches. The three workshop test cases include an axisymmetric body, a Delta Wing-Body model, and a complete low-boom supersonic transport concept. Solution sensitivity to mesh type and sizing, and several numerical convective flux discretization choices are presented and discussed. Favorable comparison between the computational simulations and experimental data of nearand mid-field pressure signatures were obtained.

A comparison of hydroponic and soil-based screening methods to identify salt tolerance in the field in barley

PubMed Central

Tavakkoli, Ehsan; Fatehi, Foad; Rengasamy, Pichu; McDonald, Glenn K.

2012-01-01

Success in breeding crops for yield and other quantitative traits depends on the use of methods to evaluate genotypes accurately under field conditions. Although many screening criteria have been suggested to distinguish between genotypes for their salt tolerance under controlled environmental conditions, there is a need to test these criteria in the field. In this study, the salt tolerance, ion concentrations, and accumulation of compatible solutes of genotypes of barley with a range of putative salt tolerance were investigated using three growing conditions (hydroponics, soil in pots, and natural saline field). Initially, 60 genotypes of barley were screened for their salt tolerance and uptake of Na+, Cl–, and K+ at 150 mM NaCl and, based on this, a subset of 15 genotypes was selected for testing in pots and in the field. Expression of salt tolerance in saline solution culture was not a reliable indicator of the differences in salt tolerance between barley plants that were evident in saline soil-based comparisons. Significant correlations were observed in the rankings of genotypes on the basis of their grain yield production at a moderately saline field site and their relative shoot growth in pots at ECe 7.2 [Spearman’s rank correlation (rs)=0.79] and ECe 15.3 (rs=0.82) and the crucial parameter of leaf Na+ (rs=0.72) and Cl– (rs=0.82) concentrations at ECe 7.2 dS m−1. This work has established screening procedures that correlated well with grain yield at sites with moderate levels of soil salinity. This study also showed that both salt exclusion and osmotic tolerance are involved in salt tolerance and that the relative importance of these traits may differ with the severity of the salt stress. In soil, ion exclusion tended to be more important at low to moderate levels of stress but osmotic stress became more important at higher stress levels. Salt exclusion coupled with a synthesis of organic solutes were shown to be important components of salt tolerance in the tolerant genotypes and further field tests of these plants under stress conditions will help to verify their potential utility in crop-improvement programmes. PMID:22442423

Bioaccumulation of toxic substances associated with dredging and dredged material disposal: a literature review

USGS Publications Warehouse

Seelye, James G.; Mac, Michael J.

1984-01-01

A literature review of sediment bioassessment was conducted as the first step in the development of a more standardized and ecologically sound test procedure for evaluating sediment quality. Based on the review, the authors concluded that 1) a standardized laboratory bioassessment test should consist of flowthrough exposure of at least 10 days duration using more than one aquatic organism including at least an infaunal benthic invertebrate and a fish species. 2) Before adoption of a laboratory sediment bioassessment procedure, the laboratory results should be evaluated by comparison with field conditions. 3) Most current sediment bioassessment regulatory tests measure acute toxicity or bioaccumulation. Development of tests to evaluate chronic, sublethal effects is needed.

Mutation Testing for Effective Verification of Digital Components of Physical Systems

NASA Astrophysics Data System (ADS)

Kushik, N. G.; Evtushenko, N. V.; Torgaev, S. N.

2015-12-01

Digital components of modern physical systems are often designed applying circuitry solutions based on the field programmable gate array technology (FPGA). Such (embedded) digital components should be carefully tested. In this paper, an approach for the verification of digital physical system components based on mutation testing is proposed. The reference description of the behavior of a digital component in the hardware description language (HDL) is mutated by introducing into it the most probable errors and, unlike mutants in high-level programming languages, the corresponding test case is effectively derived based on a comparison of special scalable representations of the specification and the constructed mutant using various logic synthesis and verification systems.

Methods for the field evaluation of quantitative G6PD diagnostics: a review.

PubMed

Ley, Benedikt; Bancone, Germana; von Seidlein, Lorenz; Thriemer, Kamala; Richards, Jack S; Domingo, Gonzalo J; Price, Ric N

2017-09-11

Individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency are at risk of severe haemolysis following the administration of 8-aminoquinoline compounds. Primaquine is the only widely available 8-aminoquinoline for the radical cure of Plasmodium vivax. Tafenoquine is under development with the potential to simplify treatment regimens, but point-of-care (PoC) tests will be needed to provide quantitative measurement of G6PD activity prior to its administration. There is currently a lack of appropriate G6PD PoC tests, but a number of new tests are in development and are likely to enter the market in the coming years. As these are implemented, they will need to be validated in field studies. This article outlines the technical details for the field evaluation of novel quantitative G6PD diagnostics such as sample handling, reference testing and statistical analysis. Field evaluation is based on the comparison of paired samples, including one sample tested by the new assay at point of care and one sample tested by the gold-standard reference method, UV spectrophotometry in an established laboratory. Samples can be collected as capillary or venous blood; the existing literature suggests that potential differences in capillary or venous blood are unlikely to affect results substantially. The collection and storage of samples is critical to ensure preservation of enzyme activity, it is recommended that samples are stored at 4 °C and testing occurs within 4 days of collection. Test results can be visually presented as scatter plot, Bland-Altman plot, and a histogram of the G6PD activity distribution of the study population. Calculating the adjusted male median allows categorizing results according to G6PD activity to calculate standard performance indicators and to perform receiver operating characteristic (ROC) analysis.

The Sim-SEQ Project: Comparison of Selected Flow Models for the S-3 Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mukhopadhyay, Sumit; Doughty, Christine A.; Bacon, Diana H.

Sim-SEQ is an international initiative on model comparison for geologic carbon sequestration, with an objective to understand and, if possible, quantify model uncertainties. Model comparison efforts in Sim-SEQ are at present focusing on one specific field test site, hereafter referred to as the Sim-SEQ Study site (or S-3 site). Within Sim-SEQ, different modeling teams are developing conceptual models of CO2 injection at the S-3 site. In this paper, we select five flow models of the S-3 site and provide a qualitative comparison of their attributes and predictions. These models are based on five different simulators or modeling approaches: TOUGH2/EOS7C, STOMP-CO2e,more » MoReS, TOUGH2-MP/ECO2N, and VESA. In addition to model-to-model comparison, we perform a limited model-to-data comparison, and illustrate how model choices impact model predictions. We conclude the paper by making recommendations for model refinement that are likely to result in less uncertainty in model predictions.« less

TH-EF-BRB-11: Volumetric Modulated Arc Therapy for Total Body Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouyang, L; Folkerts, M; Hrycushko, B

Purpose: To develop a modern, patient-comfortable total body irradiation (TBI) technique suitable for standard-sized linac vaults. Methods: An indexed rotatable immobilization system (IRIS) was developed to make possible total-body CT imaging and radiation delivery on conventional couches. Treatment consists of multi-isocentric volumetric modulated arc therapy (VMAT) to the upper body and parallel-opposed fields to the lower body. Each isocenter is indexed to the couch and includes a 180° IRIS rotation between the upper and lower body fields. VMAT fields are optimized to satisfy lung dose objectives while achieving a uniform therapeutic dose to the torso. End-to-end tests with a randomore » phantom were used to verify dosimetric characteristics. Treatment plan robustness regarding setup uncertainty was assessed by simulating global and regional isocenter setup shifts on patient data sets. Dosimetric comparisons were made with conventional extended distance, standing TBI (cTBI) plans using a Monte Carlo-based calculation. Treatment efficiency was assessed for eight courses of patient treatment. Results: The IRIS system is level and orthogonal to the scanned CT image plane, with lateral shifts <2mm following rotation. End-to-end tests showed surface doses within ±10% of the prescription dose, field junction doses within ±15% of prescription dose. Plan robustness tests showed <15% changes in dose with global setup errors up to 5mm in each direction. Local 5mm relative setup errors in the chest resulted in < 5% dose changes. Local 5mm shift errors in the pelvic and upper leg junction resulted in <10% dose changes while a 10mm shift error causes dose changes up to 25%. Dosimetric comparison with cTBI showed VMAT-TBI has advantages in preserving chest wall dose with flexibility in leveraging the PTV-body and PTV-lung dose. Conclusion: VMAT-TBI with the IRIS system was shown clinically feasible as a cost-effective approach to TBI for standard-sized linac vaults.« less

Comparison of full-field interferometric measurement techniques applied to small vibration amplitudes determination

NASA Astrophysics Data System (ADS)

Styk, Adam

2014-07-01

Classical time-averaging and stroboscopic interferometry are widely used for MEMS/MOEMS dynamic behavior investigations. Unfortunately both methods require an amplitude magnitude of at least 0.19λ to be able to detect resonant frequency of the object. Moreover the precision of measurement is limited. That puts strong constrains on the type of element to be tested. In this paper the comparison of two methods of microobject vibration measurements that overcome aforementioned problems are presented. Both methods maintain high speed measurement time and extend the range of amplitudes to be measured (below 0.19λ), moreover can be easily applied to MEMS/MOEMS dynamic parameters measurements.

The gj factor of a bound electron and the hyperfine structure splitting in hydrogenlike ions

NASA Astrophysics Data System (ADS)

Beier, Thomas

2000-12-01

The comparison between theory and experiment of the hyperfine structure splitting and the electronic gj factor in heavy highly charged ions provides a unique testing ground for quantum electrodynamics in the presence of strong electric and magnetic fields. A theoretical evaluation is presented of all quantum electrodynamical contributions to the ground-state hfs splitting in hydrogenlike and lithiumlike atoms as well as to the gj factor. Binding and nuclear effects are discussed as well. A comparison with the available experimental data is performed, and a detailed discussion of theoretical sources of uncertainty is included which is mainly due to insufficiently known nuclear properties.

Standardization Tests of NACA No. 1 Wind Tunnel

NASA Technical Reports Server (NTRS)

Reid, Elliott G

1925-01-01

The tests described in this report were made in the 5-foot atmospheric wind tunnel of the National Advisory Committee for Aeronautics, at Langley Field. The primary objective of collecting data on the characteristics of this tunnel for comparison with those of others throughout the world, in order that, in the future, the results of tests made in all the principle laboratories may be interpreted, compared, and coordinated on a basis of scientifically established relationships, a process hitherto impossible due to the lack of comparable data. The work includes tests of a disk, spheres, cylinders, and airfoils, explorations of the test section for static pressure and velocity distribution, and determination of the variations of air flow direction throughout the operating range of the tunnel. (author)

Field application of activated carbon amendment for in-situ stabilization of polychlorinated biphenyls in marine sediment.

PubMed

Cho, Yeo-Myoung; Ghosh, Upal; Kennedy, Alan J; Grossman, Adam; Ray, Gary; Tomaszewski, Jeanne E; Smithenry, Dennis W; Bridges, Todd S; Luthy, Richard G

2009-05-15

We report results on the first field-scale application of activated carbon (AC) amendment to contaminated sediment for in-situ stabilization of polychlorinated biphenyls (PCBs). The test was performed on a tidal mud flat at South Basin, adjacent to the former Hunters Point Naval Shipyard, San Francisco Bay, CA. The major goals of the field study were to (1) assess scale up of the AC mixing technology using two available, large-scale devices, (2) validate the effectiveness of the AC amendment at the field scale, and (3) identify possible adverse effects of the remediation technology. Also, the test allowed comparison among monitoring tools, evaluation of longer-term effectiveness of AC amendment, and identification of field-related factors that confound the performance of in-situ biological assessments. Following background pretreatment measurements, we successfully incorporated AC into sediment to a nominal 30 cm depth during a single mixing event, as confirmed by total organic carbon and black carbon contents in the designated test plots. The measured AC dose averaged 2.0-3.2 wt% and varied depending on sampling locations and mixing equipment. AC amendment did not impact sediment resuspension or PCB release into the water column over the treatment plots, nor adversely impactthe existing macro benthic community composition, richness, or diversity. The PCB bioaccumulation in marine clams was reduced when exposed to sediment treated with 2% AC in comparison to the control plot Field-deployed semi permeable membrane devices and polyethylene devices showed about 50% reduction in PCB uptake in AC-treated sediment and similar reduction in estimated pore-water PCB concentration. This reduction was evident even after 13-month post-treatment with then 7 months of continuous exposure, indicating AC treatment efficacy was retained for an extended period. Aqueous equilibrium PCB concentrations and PCB desorption showed an AC-dose response. Field-exposed AC after 18 months retained a strong stabilization capability to reduce aqueous equilibrium PCB concentrations by about 90%, which also supports the long-term effectiveness of AC in the field. Additional mixing during or after AC deployment, increasing AC dose, reducing AC-particle size, and sequential deployment of AC dose will likely improve AC-sediment contact and overall effectiveness. The reductions in PCB availability observed with slow mass transfer under field conditions calls for predictive models to assess the long-term trends in pore-water PCB concentrations and the benefits of alternative in-situ AC application and mixing strategies.

Comparison of on-site field measured inorganic arsenic in rice with laboratory measurements using a field deployable method: Method validation.

PubMed

Mlangeni, Angstone Thembachako; Vecchi, Valeria; Norton, Gareth J; Raab, Andrea; Krupp, Eva M; Feldmann, Joerg

2018-10-15

A commercial arsenic field kit designed to measure inorganic arsenic (iAs) in water was modified into a field deployable method (FDM) to measure iAs in rice. While the method has been validated to give precise and accurate results in the laboratory, its on-site field performance has not been evaluated. This study was designed to test the method on-site in Malawi in order to evaluate its accuracy and precision in determination of iAs on-site by comparing with a validated reference method and giving original data on inorganic arsenic in Malawian rice and rice-based products. The method was validated by using the established laboratory-based HPLC-ICPMS. Statistical tests indicated there were no significant differences between on-site and laboratory iAs measurements determined using the FDM (p = 0.263, ά = 0.05) and between on-site measurements and measurements determined using HPLC-ICP-MS (p = 0.299, ά = 0.05). This method allows quick (within 1 h) and efficient screening of rice containing iAs concentrations on-site. Copyright © 2018 Elsevier Ltd. All rights reserved.

Meta-analysis of correlations revisited: attempted replication and extension of Field's (2001) simulation studies.

PubMed

Hafdahl, Adam R; Williams, Michelle A

2009-03-01

In 2 Monte Carlo studies of fixed- and random-effects meta-analysis for correlations, A. P. Field (2001) ostensibly evaluated Hedges-Olkin-Vevea Fisher-z and Schmidt-Hunter Pearson-r estimators and tests in 120 conditions. Some authors have cited those results as evidence not to meta-analyze Fisher-z correlations, especially with heterogeneous correlation parameters. The present attempt to replicate Field's simulations included comparisons with analytic values as well as results for efficiency and confidence-interval coverage. Field's results under homogeneity were mostly replicable, but those under heterogeneity were not: The latter exhibited up to over .17 more bias than ours and, for tests of the mean correlation and homogeneity, respectively, nonnull rejection rates up to .60 lower and .65 higher. Changes to Field's observations and conclusions are recommended, and practical guidance is offered regarding simulation evidence and choices among methods. Most cautions about poor performance of Fisher-z methods are largely unfounded, especially with a more appropriate z-to-r transformation. The Appendix gives a computer program for obtaining Pearson-r moments from a normal Fisher-z distribution, which is used to demonstrate distortion due to direct z-to-r transformation of a mean Fisher-z correlation.

Toxicity and bioaccumulation of sediment-associated contaminants using freshwater invertebrates: A review of methods and applications

USGS Publications Warehouse

Ingersoll, C.G.; Ankley, G.T.; Benoit, D.A.; Brunson, E.L.; Burton, G.A.; Dwyer, F.J.; Hoke, R.A.; Landrum, P.F.; Norberg-King, T. J.; Winger, P.V.

1995-01-01

This paper reviews recent developments in methods for evaluating the toxicity and bioaccumulation of contaminants associated with freshwater sediments and summarizes example case studies demonstrating the application of these methods. Over the past decade, research has emphasized development of more specific testing procedures for conducting 10-d toxicity tests with the amphipod Hyalella azteca and the midge Chironomus tentans. Toxicity endpoints measured in these tests are survival for H. azteca and survival and growth for C. tentans. Guidance has also been developed for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus, including determination of bioaccumulation kinetics for different compound classes. These methods have been applied to a variety of sediments to address issues ranging from site assessments to bioavailability of organic and inorganic contaminants using field-collected and laboratory-spiked samples. Survival and growth of controls routinely meet or exceed test acceptability criteria. Results of laboratory bioaccumulation studies with L. variegatus have been confirmed with comparisons to residues (PCBs, PAHs, DDT) present from synoptically collected field populations of oligochaetes. Additional method development is currently underway to develop chronic toxicity tests and to provide additional data-confirming responses observed in laboratory sediment tests with natural benthic populations.

A Comparison of Pre-Test Means from Oil Field Workers Having Available Manuals and Those Lacking Manuals before Announced Training.

ERIC Educational Resources Information Center

Zambon, Franco

A study assessed the validity of the hypothesis that offshore drilling personnel would independently study important material if they knew that they would eventually receive formal training on the topic covered in the material. Eighty-one crew members on an offshore drilling rig were randomly divided into experimental and control groups. Those in…

Comparison of regression and geostatistical methods for mapping Leaf Area Index (LAI) with Landsat ETM+ data over a boreal forest.

Treesearch

Mercedes Berterretche; Andrew T. Hudak; Warren B. Cohen; Thomas K. Maiersperger; Stith T. Gower; Jennifer Dungan

2005-01-01

This study compared aspatial and spatial methods of using remote sensing and field data to predict maximum growing season leaf area index (LAI) maps in a boreal forest in Manitoba, Canada. The methods tested were orthogonal regression analysis (reduced major axis, RMA) and two geostatistical techniques: kriging with an external drift (KED) and sequential Gaussian...

Field Comparison between Sling Psychrometer and Meteorological Measuring Set AN/TMQ-22

DTIC Science & Technology

the ML-224 Sling Psychrometer . From a series of independent tests designed to minimize error it was concluded that the AN/TMQ-22 yielded a more accurate...dew point reading. The average relative humidity error using the sling psychrometer was +9% while the AN/TMQ-22 had a plus or minus 2% error. Even with cautious measurement the sling yielded a +4% error.

A "TEST OF CONCEPT" COMPARISON OF AERODYNAMIC AND MECHANICAL RESUSPENSION MECHANISMS FOR PARTICLES DEPOSITED ON FIELD RYE GRASS (SECALS CERCELE). PART 2. THRESHOLD MECHANICAL ENERGIES FOR RESUSPENSION PARTICLE FLUXES

EPA Science Inventory

Kinetic energy from the oscillatory impacts of the grass stalk against a stationary object was measured with a kinetic energy measuring device. These energy inputs were measured as part of a resuspension experiment of uniform latex microspheres deposited on a single rye grass see...

Honing the accuracy of extreme-ultraviolet optical system testing: at-wavelength and visible-light measurements of the ETS Set-2 projection optic

NASA Astrophysics Data System (ADS)

Goldberg, Kenneth A.; Naulleau, Patrick P.; Bokor, Jeffrey; Chapman, Henry N.

2002-07-01

As the quality of optical systems for extreme ultraviolet lithography improves, high-accuracy wavefront metrology for alignment and qualification becomes ever more important. To enable the development of diffraction-limited EUV projection optics, visible-light and EUV interferometries must work in close collaboration. We present a detailed comparison of EUV and visible-light wavefront measurements performed across the field of view of a lithographic-quality EUV projection optical system designed for use in the Engineering Test Stand developed by the Virtual National Laboratory and the EUV Limited Liability Company. The comparisons reveal that the present level of RMS agreement lies in the 0.3-0.4-nm range. Astigmatism is the most significant aberration component for the alignment of this optical system; it is also the dominant term in the discrepancy, and the aberration with the highest measurement uncertainty. With EUV optical systems requiring total wavefront quality in the (lambda) EUV/50 range, and even higher surface-figure quality for the individual mirror elements, improved accuracy through future comparisons, and additional studies, are required.

A scoring metric for multivariate data for reproducibility analysis using chemometric methods

PubMed Central

Sheen, David A.; de Carvalho Rocha, Werickson Fortunato; Lippa, Katrice A.; Bearden, Daniel W.

2017-01-01

Process quality control and reproducibility in emerging measurement fields such as metabolomics is normally assured by interlaboratory comparison testing. As a part of this testing process, spectral features from a spectroscopic method such as nuclear magnetic resonance (NMR) spectroscopy are attributed to particular analytes within a mixture, and it is the metabolite concentrations that are returned for comparison between laboratories. However, data quality may also be assessed directly by using binned spectral data before the time-consuming identification and quantification. Use of the binned spectra has some advantages, including preserving information about trace constituents and enabling identification of process difficulties. In this paper, we demonstrate the use of binned NMR spectra to conduct a detailed interlaboratory comparison and composition analysis. Spectra of synthetic and biologically-obtained metabolite mixtures, taken from a previous interlaboratory study, are compared with cluster analysis using a variety of distance and entropy metrics. The individual measurements are then evaluated based on where they fall within their clusters, and a laboratory-level scoring metric is developed, which provides an assessment of each laboratory’s individual performance. PMID:28694553

Between and within laboratory reliability of mouse behaviour recorded in home-cage and open-field.

PubMed

Robinson, Lianne; Spruijt, Berry; Riedel, Gernot

2018-04-15

Reproducibility of behavioural findings between laboratories is difficult due to behaviour being sensitive to environmental factors and interactions with genetics. The objective of this study was to investigate reproducibility of behavioural data between laboratories using the PhenoTyper home cage observation system and within laboratory reproducibility using different lighting regimes. The ambulatory activity of C57BL/6 and DBA/2 mice was tested in PhenoTypers in two laboratories under near identical housing and testing conditions (Exp. 1). Additionally activity and anxiety were also assessed in the open-field test. Furthermore, testing in either a normal or inverted light/dark cycle was used to determine effects of lighting regime in a within-laboratory comparison in Aberdeen (Exp. 2). Using the PhenoTyper similar circadian rhythms were observed across laboratories. Higher levels of baseline and novelty-induced activity were evident in Aberdeen compared to Utrecht although strain differences were consistent between laboratories. Open field activity was also similar across laboratories whereas strain differences in anxiety were different. Within laboratory analysis of different lighting regimes revealed that behaviour of the mice was sensitive to changes in lighting. Utilisation of a home cage observation system facilitates the reproducibility of activity but not anxiety-related behaviours across laboratories by eliminating environmental factors known to influence reproducibility in standard behavioural tests. Standardisation of housing/test conditions resulted in reproducibility of home cage and open field activity but not anxiety-related phenotypes across laboratories with some behaviours more sensitive to environmental factors. Environmental factors include lighting and time of day. Copyright © 2017 Elsevier B.V. All rights reserved.

Results of external quality-assurance program for the National Atmospheric Deposition Program and National Trends Network during 1985

USGS Publications Warehouse

Brooks, M.H.; Schroder, L.J.; Willoughby, T.C.

1988-01-01

External quality assurance monitoring of the National Atmospheric Deposition Program (NADP) and National Trends Network (NTN) was performed by the U.S. Geological Survey during 1985. The monitoring consisted of three primary programs: (1) an intersite comparison program designed to assess the precision and accuracy of onsite pH and specific conductance measurements made by NADP and NTN site operators; (2) a blind audit sample program designed to assess the effect of routine field handling on the precision and bias of NADP and NTN wet deposition data; and (3) an interlaboratory comparison program designed to compare analytical data from the laboratory processing NADP and NTN samples with data produced by other laboratories routinely analyzing wet deposition samples and to provide estimates of individual laboratory precision. An average of 94% of the site operators participated in the four voluntary intersite comparisons during 1985. A larger percentage of participating site operators met the accuracy goal for specific conductance measurements (average, 87%) than for pH measurements (average, 67%). Overall precision was dependent on the actual specific conductance of the test solution and independent of the pH of the test solution. Data for the blind audit sample program indicated slight positive biases resulting from routine field handling for all analytes except specific conductance. These biases were not large enough to be significant for most data users. Data for the blind audit sample program also indicated that decreases in hydrogen ion concentration were accompanied by decreases in specific conductance. Precision estimates derived from the blind audit sample program indicate that the major source of uncertainty in wet deposition data is the routine field handling that each wet deposition sample receives. Results of the interlaboratory comparison program were similar to results of previous years ' evaluations, indicating that the participating laboratories produced comparable data when they analyzed identical wet deposition samples, and that the laboratory processing NADP and NTN samples achieved the best analyte precision of the participating laboratories. (Author 's abstract)

Hypersonic Navier Stokes Comparisons to Orbiter Flight Data

NASA Technical Reports Server (NTRS)

Campbell, Charles H.; Nompelis, Ioannis; Candler, Graham; Barnhart, Michael; Yoon, Seokkwan

2009-01-01

Hypersonic chemical nonequilibrium simulations of low earth orbit entry flow fields are becoming increasingly commonplace as software and computational capabilities become more capable. However, development of robust and accurate software to model these environments will always encounter a significant barrier in developing a suite of high quality calibration cases. The US3D hypersonic nonequilibrium Navier Stokes analysis capability has been favorably compared to a number of wind tunnel test cases. Extension of the calibration basis for this software to Orbiter flight conditions will provide an incremental increase in confidence. As part of the Orbiter Boundary Layer Transition Flight Experiment and the Hypersonic Thermodynamic Infrared Measurements project, NASA is performing entry flight testing on the Orbiter to provide valuable aerothermodynamic heating data. An increase in interest related to orbiter entry environments is resulting from this activity. With the advent of this new data, comparisons of the US3D software to the new flight testing data is warranted. This paper will provide information regarding the framework of analyses that will be applied with the US3D analysis tool. In addition, comparisons will be made to entry flight testing data provided by the Orbiter BLT Flight Experiment and HYTHIRM projects. If data from digital scans of the Orbiter windward surface become available, simulations will also be performed to characterize the difference in surface heating between the CAD reference OML and the digitized surface provided by the surface scans.

Detection of Visual Field Loss in Pituitary Disease: Peripheral Kinetic Versus Central Static

PubMed Central

Rowe, Fiona J.; Cheyne, Christopher P.; García-Fiñana, Marta; Noonan, Carmel P.; Howard, Claire; Smith, Jayne; Adeoye, Joanne

2015-01-01

Abstract Visual field assessment is an important clinical evaluation for eye disease and neurological injury. We evaluated Octopus semi-automated kinetic peripheral perimetry (SKP) and Humphrey static automated central perimetry for detection of neurological visual field loss in patients with pituitary disease. We carried out a prospective cross-sectional diagnostic accuracy study comparing Humphrey central 30-2 SITA threshold programme with a screening protocol for SKP on Octopus perimetry. Humphrey 24-2 data were extracted from 30-2 results. Results were independently graded for presence/absence of field defect plus severity of defect. Fifty patients (100 eyes) were recruited (25 males and 25 females), with mean age of 52.4 years (SD = 15.7). Order of perimeter assessment (Humphrey/Octopus first) and order of eye tested (right/left first) were randomised. The 30-2 programme detected visual field loss in 85%, the 24-2 programme in 80%, and the Octopus combined kinetic/static strategy in 100% of eyes. Peripheral visual field loss was missed by central threshold assessment. Qualitative comparison of type of visual field defect demonstrated a match between Humphrey and Octopus results in 58%, with a match for severity of defect in 50%. Tests duration was 9.34 minutes (SD = 2.02) for Humphrey 30-2 versus 10.79 minutes (SD = 4.06) for Octopus perimetry. Octopus semi-automated kinetic perimetry was found to be superior to central static testing for detection of pituitary disease-related visual field loss. Where reliant on Humphrey central static perimetry, the 30-2 programme is recommended over the 24-2 programme. Where kinetic perimetry is available, this is preferable to central static programmes for increased detection of peripheral visual field loss. PMID:27928344

Screening of willow species for resistance to heavy metals: comparison of performance in a hydroponics system and field trials.

PubMed

Watson, C; Pulford, I D; Riddell-Black, D

2003-01-01

The aim of this study was to ascertain whether metal resistance in willow (Salix) clones grown in a hydroponics screening test correlated with data from the same clones grown independently in a field trial. If so, results from a short-term, glasshouse-based system could be extrapolated to the field, allowing rapid identification of willows suitable for planting in metal-contaminated substrates without necessitating longterm field trials. Principal Components Analysis was used to show groups of clones and to assess the relative importance of the parameters measured in both the hydroponics system and the field; including plant response factors such as increase in stem height, as well as metal concentrations in plant tissues. The clones tested fell into two distinct groups. Salix viminalis clones and the basket willow Black Maul (S. triandra) were less resistant to elevated concentrations of heavy metals than a group of hardier clones, including S. burjatica 'Germany,' S.x dasyclados, S. candida and S. spaethii. The more resistant clones produced more biomass in the glasshouse and field, and had higher metal concentrations in the wood. The less resistant clones had greater concentrations of Cu and Ni in the bark, and produced less biomass in the glasshouse and field. Significant relationships were found between the response of the same clones grown the in short-term glasshouse hydroponics system and in the field.

Teaching accreditation exams reveal grading biases favor women in male-dominated disciplines in France.

PubMed

Breda, Thomas; Hillion, Mélina

2016-07-29

Discrimination against women is seen as one of the possible causes behind their underrepresentation in certain STEM (science, technology, engineering, and mathematics) subjects. We show that this is not the case for the competitive exams used to recruit almost all French secondary and postsecondary teachers and professors. Comparisons of oral non-gender-blind tests with written gender-blind tests for about 100,000 individuals observed in 11 different fields over the period 2006-2013 reveal a bias in favor of women that is strongly increasing with the extent of a field's male-domination. This bias turns from 3 to 5 percentile ranks for men in literature and foreign languages to about 10 percentile ranks for women in math, physics, or philosophy. These findings have implications for the debate over what interventions are appropriate to increase the representation of women in fields in which they are currently underrepresented. Copyright © 2016, American Association for the Advancement of Science.

Measurements of the Basic SR-71 Airplane Near-Field Signature

NASA Technical Reports Server (NTRS)

Haering, Edward A., Jr.; Whitmore, Stephen A.; Ehernberger, L. J.

1999-01-01

Airplane design studies have developed configuration concepts that may produce lower sonic boom annoyance levels. Since lower noise designs differ significantly from other HSCT designs, it is necessary to accurately assess their potential before HSCT final configuration decisions are made. Flight tests to demonstrate lower noise design capability by modifying an existing airframe have been proposed for the Mach 3 SR-71 reconnaissance airplane. To support the modified SR-71 proposal, baseline in-flight measurements were made of the unmodified aircraft. These measurements of SR-71 near-field sonic boom signatures were obtained by an F-16XL probe airplane at flightpath separation distances ranging from approximately 740 to 40 ft. This paper discusses the methods used to gather and analyze the flight data, and makes comparisons of these flight data with CFD results from Douglas Aircraft Corporation and NASA Langley Research Center. The CFD solutions were obtained for the near-field flow about the SR-71, and then propagated to the flight test measurement location using the program MDBOOM.

Pattern recognition of satellite cloud imagery for improved weather prediction

NASA Technical Reports Server (NTRS)

Gautier, Catherine; Somerville, Richard C. J.; Volfson, Leonid B.

1986-01-01

The major accomplishment was the successful development of a method for extracting time derivative information from geostationary meteorological satellite imagery. This research is a proof-of-concept study which demonstrates the feasibility of using pattern recognition techniques and a statistical cloud classification method to estimate time rate of change of large-scale meteorological fields from remote sensing data. The cloud classification methodology is based on typical shape function analysis of parameter sets characterizing the cloud fields. The three specific technical objectives, all of which were successfully achieved, are as follows: develop and test a cloud classification technique based on pattern recognition methods, suitable for the analysis of visible and infrared geostationary satellite VISSR imagery; develop and test a methodology for intercomparing successive images using the cloud classification technique, so as to obtain estimates of the time rate of change of meteorological fields; and implement this technique in a testbed system incorporating an interactive graphics terminal to determine the feasibility of extracting time derivative information suitable for comparison with numerical weather prediction products.

Field performance of a geosynthetic clay liner landfill capping system under simulated waste subsidence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiss, W.; Siegmund, M.; Alexiew, D.

1995-10-01

A flexible landfill capping system consisting of a 3-D-geocore composite for gas vent, a Geosynthetic Clay Liner (GCL) for sealing and a 3-D-geocore composite for drainage of the vegetation soil was built on a test field at Michelshoehe landfill near Weimar, Germany. At four locations airbags were installed underneath the thin capping system to simulate subsidences. On top of three of these airbags overlaps of the GCL were positioned, for comparison there was no overlap at the fourth location. After hydratation of the GCL the airbags were de-aerated and subsidences occurred with app. 5 % tensile strain in the GCL.more » For three weeks the test field was intensively sprinkled in intervals. Then horizontal and vertical deformations were measured, but not displacements were registered in the overlaps. The evaluation of the GCL`s permeability showed no significant difference between the locations with and without overlaps.« less

Removing systematic errors in interionic potentials of mean force computed in molecular simulations using reaction-field-based electrostatics

PubMed Central

Baumketner, Andrij

2009-01-01

The performance of reaction-field methods to treat electrostatic interactions is tested in simulations of ions solvated in water. The potential of mean force between sodium chloride pair of ions and between side chains of lysine and aspartate are computed using umbrella sampling and molecular dynamics simulations. It is found that in comparison with lattice sum calculations, the charge-group-based approaches to reaction-field treatments produce a large error in the association energy of the ions that exhibits strong systematic dependence on the size of the simulation box. The atom-based implementation of the reaction field is seen to (i) improve the overall quality of the potential of mean force and (ii) remove the dependence on the size of the simulation box. It is suggested that the atom-based truncation be used in reaction-field simulations of mixed media. PMID:19292522

Borehole measurement of the hydraulic properties of low-permeability rock

NASA Astrophysics Data System (ADS)

Novakowski, Kentner S.; Bickerton, Gregory S.

1997-11-01

Hydraulic tests conducted in low-permeability media are subject to numerous influences and processes, many of which manifest in a nonunique fashion. To explore the accuracy and meaning of the interpretation of hydraulic tests conducted under such conditions, two semianalytical models are developed in which variable well bore storage, variable temperature, and test method are considered. The formation is assumed to be of uniform permeability and uniform storativity in both models. To investigate uncertainty in the use of these models, a comparison is conducted to similar models that account for nonuniform formation properties such as finite skin, double porosity, and fractional flow. Using the models for a finite skin and double porosity as baseline cases, results show that the interpretation of slug tests are normally nonunique when tests are conducted in material of low permeability. Provided that a lower bound is defined for storativity, the uncertainty in a given interpretation conducted with the model for a uniform medium can be established by comparison with a fit to the data obtained using the model incorporating finite skin. It was also found that the degree of uncertainty can be diminished by conducting the test using an open hole period followed by a shut-in period (similar to a drill stem test). Determination of the degree of uncertainty was found to be case specific and must be defined by using at least a comparison between the model for uniform media and that for finite skin. To illustrate the use of the slug test model and determine the degree of uncertainty that will accrue with the use of that model, a field example, potentially influenced by variable well bore storage, is presented and interpreted.

Fast solver for large scale eddy current non-destructive evaluation problems

NASA Astrophysics Data System (ADS)

Lei, Naiguang

Eddy current testing plays a very important role in non-destructive evaluations of conducting test samples. Based on Faraday's law, an alternating magnetic field source generates induced currents, called eddy currents, in an electrically conducting test specimen. The eddy currents generate induced magnetic fields that oppose the direction of the inducing magnetic field in accordance with Lenz's law. In the presence of discontinuities in material property or defects in the test specimen, the induced eddy current paths are perturbed and the associated magnetic fields can be detected by coils or magnetic field sensors, such as Hall elements or magneto-resistance sensors. Due to the complexity of the test specimen and the inspection environments, the availability of theoretical simulation models is extremely valuable for studying the basic field/flaw interactions in order to obtain a fuller understanding of non-destructive testing phenomena. Theoretical models of the forward problem are also useful for training and validation of automated defect detection systems. Theoretical models generate defect signatures that are expensive to replicate experimentally. In general, modelling methods can be classified into two categories: analytical and numerical. Although analytical approaches offer closed form solution, it is generally not possible to obtain largely due to the complex sample and defect geometries, especially in three-dimensional space. Numerical modelling has become popular with advances in computer technology and computational methods. However, due to the huge time consumption in the case of large scale problems, accelerations/fast solvers are needed to enhance numerical models. This dissertation describes a numerical simulation model for eddy current problems using finite element analysis. Validation of the accuracy of this model is demonstrated via comparison with experimental measurements of steam generator tube wall defects. These simulations generating two-dimension raster scan data typically takes one to two days on a dedicated eight-core PC. A novel direct integral solver for eddy current problems and GPU-based implementation is also investigated in this research to reduce the computational time.

Comparison of Quality and Output of Different Optimal Perimetric Testing Approaches in Children With Glaucoma.

PubMed

Patel, Dipesh E; Cumberland, Phillippa M; Walters, Bronwen C; Russell-Eggitt, Isabelle; Brookes, John; Papadopoulos, Maria; Khaw, Peng Tee; Viswanathan, Ananth C; Garway-Heath, David; Cortina-Borja, Mario; Rahi, Jugnoo S

2018-02-01

There is limited evidence to support the development of guidance for visual field testing in children with glaucoma. To compare different static and combined static/kinetic perimetry approaches in children with glaucoma. Cross-sectional, observational study recruiting children prospectively between May 2013 and June 2015 at 2 tertiary specialist pediatric ophthalmology centers in London, England (Moorfields Eye Hospital and Great Ormond Street Hospital). The study included 65 children aged 5 to 15 years with glaucoma (108 affected eyes). A comparison of test quality and outcomes for static and combined static/kinetic techniques, with respect to ability to quantify glaucomatous loss. Children performed perimetric assessments using Humphrey static (Swedish Interactive Thresholding Algorithm 24-2 FAST) and Octopus combined static tendency-oriented perimetry/kinetic perimetry (isopter V4e, III4e, or I4e) in a single sitting, using standardized clinical protocols, administered by a single examiner. Information was collected about test duration, completion, and quality (using automated reliability indices and our qualitative Examiner-Based Assessment of Reliability score). Perimetry outputs were scored using the Aulhorn and Karmeyer classification. One affected eye in 19 participants was retested with Swedish Interactive Thresholding Algorithm 24-2 FAST and 24-2 standard algorithms. Sixty-five children (33 girls [50.8%]), with a median age of 12 years (interquartile range, 9-14 years), were tested. Test quality (Examiner-Based Assessment of Reliability score) improved with increasing age for both Humphrey and Octopus strategies and were equivalent in children older than 10 years (McNemar test, χ2 = 0.33; P = .56), but better-quality tests with Humphrey perimetry were achieved in younger children (McNemar test, χ2 = 4.0; P = .05). Octopus and Humphrey static MD values worse than or equal to -6 dB showed disagreement (Bland-Altman, mean difference, -0.70; limit of agreement, -7.74 to 6.35) but were comparable when greater than this threshold (mean difference, -0.03; limit of agreement, -2.33 to 2.27). Visual field classification scores for static perimetry tests showed substantial agreement (linearly weighted κ, 0.79; 95% CI, 0.65-0.93), although 25 of 80 (31%) were graded with a more severe defect for Octopus static perimetry. Of the 7 severe cases of visual field loss (grade 5), 5 had lower kinetic than static classification scores. A simple static perimetry approach potentially yields high-quality results in children younger than 10 years. For children older than 10 years, without penalizing quality, the addition of kinetic perimetry enabled measurement of far-peripheral sensitivity, which is particularly useful in children with severe visual field restriction.

Multifocal visual evoked potentials for early glaucoma detection.

PubMed

Weizer, Jennifer S; Musch, David C; Niziol, Leslie M; Khan, Naheed W

2012-07-01

To compare multifocal visual evoked potentials (mfVEP) with other detection methods in early open-angle glaucoma. Ten patients with suspected glaucoma and 5 with early open-angle glaucoma underwent mfVEP, standard automated perimetry (SAP), short-wave automated perimetry, frequency-doubling technology perimetry, and nerve fiber layer optical coherence tomography. Nineteen healthy control subjects underwent mfVEP and SAP for comparison. Comparisons between groups involving continuous variables were made using independent t tests; for categorical variables, Fisher's exact test was used. Monocular mfVEP cluster defects were associated with an increased SAP pattern standard deviation (P = .0195). Visual fields that showed interocular mfVEP cluster defects were more likely to also show superior quadrant nerve fiber layer thinning by OCT (P = .0152). Multifocal visual evoked potential cluster defects are associated with a functional and an anatomic measure that both relate to glaucomatous optic neuropathy. Copyright 2012, SLACK Incorporated.

Research for the Fluid Field of the Centrifugal Compressor Impeller in Accelerating Startup

NASA Astrophysics Data System (ADS)

Li, Xiaozhu; Chen, Gang; Zhu, Changyun; Qin, Guoliang

2013-03-01

In order to study the flow field in the impeller in the accelerating start-up process of centrifugal compressor, the 3-D and 1-D transient accelerated flow governing equations along streamline in the impeller of the centrifugal compressor are derived in detail, the assumption of pressure gradient distribution is presented, and the solving method for 1-D transient accelerating flow field is given based on the assumption. The solving method is achieved by programming and the computing result is obtained. It is obtained by comparison that the computing method is met with the test result. So the feasibility and effectiveness for solving accelerating start-up problem of centrifugal compressor by the solving method in this paper is proven.

Comparison between three option, four option and five option multiple choice question tests for quality parameters: A randomized study.

PubMed

Vegada, Bhavisha; Shukla, Apexa; Khilnani, Ajeetkumar; Charan, Jaykaran; Desai, Chetna

2016-01-01

Most of the academic teachers use four or five options per item of multiple choice question (MCQ) test as formative and summative assessment. Optimal number of options in MCQ item is a matter of considerable debate among academic teachers of various educational fields. There is a scarcity of the published literature regarding the optimum number of option in each item of MCQ in the field of medical education. To compare three options, four options, and five options MCQs test for the quality parameters - reliability, validity, item analysis, distracter analysis, and time analysis. Participants were 3 rd semester M.B.B.S. students. Students were divided randomly into three groups. Each group was given one set of MCQ test out of three options, four options, and five option randomly. Following the marking of the multiple choice tests, the participants' option selections were analyzed and comparisons were conducted of the mean marks, mean time, validity, reliability and facility value, discrimination index, point biserial value, distracter analysis of three different option formats. Students score more ( P = 0.000) and took less time ( P = 0.009) for the completion of three options as compared to four options and five options groups. Facility value was more ( P = 0.004) in three options group as compared to four and five options groups. There was no significant difference between three groups for the validity, reliability, and item discrimination. Nonfunctioning distracters were more in the four and five options group as compared to three option group. Assessment based on three option MCQs is can be preferred over four option and five option MCQs.

Population-based mammography screening: comparison of screen-film and full-field digital mammography with soft-copy reading--Oslo I study.

PubMed

Skaane, Per; Young, Kari; Skjennald, Arnulf

2003-12-01

To compare screen-film and full-field digital mammography with soft-copy reading in a population-based screening program. Full-field digital and screen-film mammography were performed in 3,683 women aged 50-69 years. Two standard views of each breast were acquired with each modality. Images underwent independent double reading with use of a five-point rating scale for probability of cancer. Recall rates and positive predictive values were calculated. Cancer detection rates determined with both modalities were compared by using the McNemar test for paired proportions. Retrospective side-by-side analysis for conspicuity of cancers was performed by an external independent radiologist group with experience in both modalities. In 3,683 cases, 31 cancers were detected. Screen-film mammography depicted 28 (0.76%) malignancies, and full-field digital mammography depicted 23 (0.62%) malignancies. The difference between cancer detection rates was not significant (P =.23). The recall rate for full-field digital mammography (4.6%; 168 of 3,683 cases) was slightly higher than that for screen-film mammography (3.5%; 128 of 3,683 cases). The positive predictive value based on needle biopsy results was 46% for screen-film mammography and 39% for full-field digital mammography. Side-by-side image comparison for cancer conspicuity led to classification of 19 cancers as equal for probability of malignancy, six cancers as slightly better demonstrated at screen-film mammography, and six cancers as slightly better demonstrated at full-field digital mammography. There was no statistically significant difference in cancer detection rate between screen-film and full-field digital mammography. Cancer conspicuity was equal with both modalities. Full-field digital mammography with soft-copy reading is comparable to screen-film mammography in population-based screening.

Comparison of Far-Field Noise for Three Significantly Different Model Turbofans

NASA Technical Reports Server (NTRS)

Woodward, Richard P.

2008-01-01

Far-field noise sound power level (PWL) spectra and overall sound pressure level (OASPL) directivities were compared for three significantly different model fan stages which were tested in the NASA Glenn 9x15 Low Speed Wind Tunnel. The test fans included the Advanced Ducted Propulsor (ADP) Fan1, the baseline Source Diagnostic Test (SDT) fan, and the Quiet High Speed Fan2 (QHSF2) These fans had design rotor tangential tip speeds from 840 to 1474 ft/s and stage pressure ratios from 1.29 to 1.82. Additional parameters included rotor-stator spacing, stator sweep, and downstream support struts. Acoustic comparison points were selected on the basis of stage thrust. Acoustic results for the low tip speed/low pressure ratio fan (ADP Fan1) were thrust-adjusted to show how a geometrically-scaled version of this fan might compare at the higher design thrust levels of the other two fans. Lowest noise levels were typically observed for ADP Fan1 (which had a radial stator) and for the intermediate tip speed fan (Source Diagnostics Test, SDT, R4 rotor) with a swept stator. Projected noise levels for the ADP fan to the SDT swept stator configuration at design point conditions showed the fans to have similar noise levels. However, it is possible that the ADP fan could be 2 to 3 dB quieter with incorporation of a swept stator. Benefits of a scaled ADP fan include avoidance of multiple pure tones associated with transonic and higher blade tip speeds. Penalties of a larger size ADP fan would include increased nacelle size and drag.

Comparison of Far-field Noise for Three Significantly Different Model Turbofans

NASA Technical Reports Server (NTRS)

Woodward, Richard P.

2008-01-01

Far-field noise sound power level (PWL) spectra and overall sound pressure level (OASPL) directivities were compared for three significantly different model fan stages which were tested in the NASA Glenn 9 15 Low Speed Wind Tunnel. The test fans included the Advanced Ducted Propulsor (ADP) Fan1, the baseline Source Diagnostic Test (SDT) fan, and the Quiet High Speed Fan2 (QHSF2). These fans had design rotor tangential tip speeds from 840 to 1474 ft/s and stage pressure ratios from 1.29 to 1.82. Additional parameters included rotor-stator spacing, stator sweep, and downstream support struts. Acoustic comparison points were selected on the basis of stage thrust. Acoustic results for the low tip speed/low pressure ratio fan (ADP Fan1) were thrust-adjusted to show how a geometrically-scaled version of this fan might compare at the higher design thrust levels of the other two fans. Lowest noise levels were typically observed for ADP Fan1 (which had a radial stator) and for the intermediate tip speed fan (Source Diagnostics Test, SDT, R4 rotor) with a swept stator. Projected noise levels for the ADP fan to the SDT swept stator configuration at design point conditions showed the fans to have similar noise levels. However, it is possible that the ADP fan could be 2 to 3 dB quieter with incorporation of a swept stator. Benefits of a scaled ADP fan include avoidance of multiple pure tones associated with transonic and higher blade tip speeds. Penalties of a larger size ADP fan would include increased nacelle size and drag.

ELF magnetic fields in electric and gasoline-powered vehicles.

PubMed

Tell, R A; Sias, G; Smith, J; Sahl, J; Kavet, R

2013-02-01

We conducted a pilot study to assess magnetic field levels in electric compared to gasoline-powered vehicles, and established a methodology that would provide valid data for further assessments. The sample consisted of 14 vehicles, all manufactured between January 2000 and April 2009; 6 were gasoline-powered vehicles and 8 were electric vehicles of various types. Of the eight models available, three were represented by a gasoline-powered vehicle and at least one electric vehicle, enabling intra-model comparisons. Vehicles were driven over a 16.3 km test route. Each vehicle was equipped with six EMDEX Lite broadband meters with a 40-1,000 Hz bandwidth programmed to sample every 4 s. Standard statistical testing was based on the fact that the autocorrelation statistic damped quickly with time. For seven electric cars, the geometric mean (GM) of all measurements (N = 18,318) was 0.095 µT with a geometric standard deviation (GSD) of 2.66, compared to 0.051 µT (N = 9,301; GSD = 2.11) for four gasoline-powered cars (P < 0.0001). Using the data from a previous exposure assessment of residential exposure in eight geographic regions in the United States as a basis for comparison (N = 218), the broadband magnetic fields in electric vehicles covered the same range as personal exposure levels recorded in that study. All fields measured in all vehicles were much less than the exposure limits published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Institute of Electrical and Electronics Engineers (IEEE). Future studies should include larger sample sizes representative of a greater cross-section of electric-type vehicles. Copyright © 2012 Wiley Periodicals, Inc.

Field hearing measurements of the Atlantic sharpnose shark Rhizoprionodon terraenovae.

PubMed

Casper, B M; Mann, D A

2009-12-01

Field measurements of hearing thresholds were obtained from the Atlantic sharpnose shark Rhizoprionodon terraenovae using the auditory evoked potential method (AEP). The fish had most sensitive hearing at 20 Hz, the lowest frequency tested, with decreasing sensitivity at higher frequencies. Hearing thresholds were lower than AEP thresholds previously measured for the nurse shark Ginglymostoma cirratum and yellow stingray Urobatis jamaicensis at frequencies <200 Hz, and similar at 200 Hz and above. Rhizoprionodon terraenovae represents the closest comparison in terms of pelagic lifestyle to the sharks which have been observed in acoustic field attraction experiments. The sound pressure levels that would be equivalent to the particle acceleration thresholds of R. terraenovae were much higher than the sound levels which attracted closely related sharks suggesting a discrepancy between the hearing threshold experiments and the field attraction experiments.

On the numerical computation of nonlinear force-free magnetic fields. [from solar photosphere

NASA Technical Reports Server (NTRS)

Wu, S. T.; Sun, M. T.; Chang, H. M.; Hagyard, M. J.; Gary, G. A.

1990-01-01

An algorithm has been developed to extrapolate nonlinear force-free magnetic fields from the photosphere, given the proper boundary conditions. This paper presents the results of this work, describing the mathematical formalism that was developed, the numerical techniques employed, and comments on the stability criteria and accuracy developed for these numerical schemes. An analytical solution is used for a benchmark test; the results show that the computational accuracy for the case of a nonlinear force-free magnetic field was on the order of a few percent (less than 5 percent). This newly developed scheme was applied to analyze a solar vector magnetogram, and the results were compared with the results deduced from the classical potential field method. The comparison shows that additional physical features of the vector magnetogram were revealed in the nonlinear force-free case.

Control of the Earth's electric field intensity through solar wind modulation of galactic cosmic radiation: Support for a proposed atmospheric electrical sun-weather mechanism

NASA Technical Reports Server (NTRS)

Markson, R.

1980-01-01

The ionospheric potential and galactic cosmic radiation, found to be inversely correlated with the solar wind velocity are examined as being germane to weather modification. Since the ionospheric potential is proportional to the fair weather electric field intensity and cosmic radiation is the dominant source of atmospheric ionization, it is concluded that the Earth's overall electric field varies in phase with atmospheric ionization and that the latter is modulated by the solar wind. A proposed mechanism, in which solar control of ionizing radiation influences atmospheric electrification and thus possibly cloud physical processes is discussed. An experimental approach to critically test the proposed mechanism through comparison of the temporal variation of the Earth's electric field with conditions in the interplanetary medium is outlined.

A comparison of artificial turf.

PubMed

Naunheim, Rosanne; Parrott, Heather; Standeven, John

2004-12-01

In an attempt to decrease injuries, newer forms of artificial turf have been marketed. The purpose of this study was to determine whether a new shredded rubber-based turf improves impact attenuation. An instrumented computerized impact recording device (IRD, Techmark, Lansing, MI) was dropped 20 times from a height of 48 inches onto five types of turf used by a professional football team. Duncan's multiple range test shows that the new rubber-based field and the older foam field are not significantly different. There were significant differences, however, between sites on the shredded rubber-based field. The change from a foam-based system to a shredded rubber-based system had no effect on impact attenuation overall. However, areas in the shredded rubber-based field were significantly compacted, causing some sites to be much harder than the foam-based surface it replaced.

Pitot pressure measurements in flow fields behind circular-arc nozzles with exhaust jets at subsonic free-stream Mach numbers. [langley 16 foot transonic tunnel

NASA Technical Reports Server (NTRS)

Mason, M. L.; Putnam, L. E.

1979-01-01

The flow field behind a circular arc nozzle with exhaust jet was studied at subsonic free stream Mach numbers. A conical probe was used to measure the pitot pressure in the jet and free stream regions. Pressure data were recorded for two nozzle configurations at nozzle pressure ratios of 2.0, 2.9, and 5.0. At each set of test conditions, the probe was traversed from the jet center line into the free stream region at seven data acquisition stations. The survey began at the nozzle exit and extended downstream at intervals. The pitot pressure data may be applied to the evaluation of computational flow field models, as illustrated by a comparison of the flow field data with results of inviscid jet plume theory.

Evaluation of eight short-term long-range transport models using field data

NASA Astrophysics Data System (ADS)

Carhart, R. A.; Policastro, A. J.; Wastag, M.; Coke, L.

Eight short-term long-range transport models (MESOPUFF, MESOPLUME, MSPUFF, MESOPUFF II, MTDDIS, ARRPA, RADM and RTM-II) have been tested with field data from two data bases involving tracer releases. The Oklahoma data base involved two separate experiments with measurements taken at 100 and 600 km arcs downwind of a 3-h perfluorocarbon release. The Savannah River Plant data base encompassed 15 experiments with measurements taken over 2-5 days at distances of 28-144 km downwind from a 62 m stack release of Kr-85 gas. Application of the American Meteorological Society statistics to the model/data comparisons showed that six of the eight models predicted within a factor of two of the observed concentrations for all of the following: points paired in space and time, points paired in space only, and for points unpaired in space and time. However, the ratio of the standard deviation of residuals to the average observed value showed improvement as more unpairing was done in the comparison of the models with the data. The statistical comparisons reveal a definite tendency of the models to overpredict plume concentrations. Supplemental graphical comparisons showed that plume concentration overprediction is accompanied with an underprediction of plume spreading, and that a definite time lag is often observed between the time of arrival of the observed plume and the time of arrival of the predicted plume. The causes of model/data discrepancies can be largely traced to inadequate wind field modeling that leads to an incorrect temporal and spatial positioning of the plume, and the use of the Turner [Workbook of atmospheric dispersion estimates. U.S. Dept of H.E.W. Publication 999-AP-26 (1970)] curves to downwind distances beyond which they can accurately represent the scales of atmospheric turbulence. The use of multilayer wind field models and the use of the Heffter [ J. appl. Met.4, 153-156 (1965)] formula for lateral plume dispersion close to the source appear to improve model accuracies.

A Note on the Fractal Behavior of Hydraulic Conductivity and Effective Porosity for Experimental Values in a Confined Aquifer

PubMed Central

De Bartolo, Samuele; Fallico, Carmine; Veltri, Massimo

2013-01-01

Hydraulic conductivity and effective porosity values for the confined sandy loam aquifer of the Montalto Uffugo (Italy) test field were obtained by laboratory and field measurements; the first ones were carried out on undisturbed soil samples and the others by slug and aquifer tests. A direct simple-scaling analysis was performed for the whole range of measurement and a comparison among the different types of fractal models describing the scale behavior was made. Some indications about the largest pore size to utilize in the fractal models were given. The results obtained for a sandy loam soil show that it is possible to obtain global indications on the behavior of the hydraulic conductivity versus the porosity utilizing a simple scaling relation and a fractal model in coupled manner. PMID:24385876

Report of secondary flows, boundary layers, turbulence and wave team, report 1

NASA Technical Reports Server (NTRS)

Scoggins, J. R.; Fitzjarrald, D.; Doviak, R.; Cliff, W.

1980-01-01

General criteria for a flight test option are that: (1) there be a good opportunity for comparison with other measurement techniques; (2) the flow to be measured is of considerable scientific or practical interest; and (3) the airborne laser Doppler system is well suited to measure the required quantities. The requirement for comparison, i.e., ground truth, is particularly important because this is the first year of operation for the system. It is necessary to demonstrate that the system does actually measure the winds and compare the results with other methods to provide a check on the system error analysis. The uniqueness of the laser Doppler system precludes any direct comparison, but point measurements from tower mounted wind sensors and two dimensional fields obtained from radars with substantially different sampling volumes are quite useful.

Evaluation of ICT filariasis card test using whole capillary blood: comparison with Knott's concentration and counting chamber methods.

PubMed

Njenga, S M; Wamae, C N

2001-10-01

An immunochromatographic card test (ICT) that uses fingerprick whole blood instead of serum for diagnosis of bancroftian filariasis has recently been developed. The card test was validated in the field in Kenya by comparing its sensitivity to the combined sensitivity of Knott's concentration and counting chamber methods. A total of 102 (14.6%) and 117 (16.7%) persons was found to be microfilaremic by Knott's concentration and counting chamber methods, respectively. The geometric mean intensities (GMI) were 74.6 microfilariae (mf)/ml and 256.5 mf/ml by Knott's concentration and counting chamber methods, respectively. All infected individuals detected by both Knott's concentration and counting chamber methods were also antigen positive by the ICT filariasis card test (100% sensitivity). Further, of 97 parasitologically amicrofilaremic persons, 24 (24.7%) were antigen positive by the ICT. The overall prevalence of antigenemia was 37.3%. Of 100 nonendemic area control persons, none was found to be filarial antigen positive (100% specificity). The results show that the new version of the ICT filariasis card test is a simple, sensitive, specific, and rapid test that is convenient in field settings.

Comparison of the release of constituents from granular materials under batch and column testing.

PubMed

Lopez Meza, Sarynna; Garrabrants, Andrew C; van der Sloot, Hans; Kosson, David S

2008-01-01

Column leaching testing can be considered a better basis for assessing field impact data than any other available batch test method and thus provides a fundamental basis from which to estimate constituent release under a variety of field conditions. However, column testing is time-intensive compared to the more simplified batch testing, and may not always be a viable option when making decisions for material reuse. Batch tests are used most frequently as a simple tool for compliance or quality control reasons. Therefore, it is important to compare the release that occurs under batch and column testing, and establish conservative interpretation protocols for extrapolation from batch data when column data are not available. Five different materials (concrete, construction debris, aluminum recycling residue, coal fly ash and bottom ash) were evaluated via batch and column testing, including different column flow regimes (continuously saturated and intermittent unsaturated flow). Constituent release data from batch and column tests were compared. Results showed no significant difference between the column flow regimes when constituent release data from batch and column tests were compared. In most cases batch and column testing agreed when presented in the form of cumulative release. For arsenic in carbonated materials, however, batch testing underestimates the column constituent release for most LS ratios and also on a cumulative basis. For cases when As is a constituent of concern, column testing may be required.

Combined use of field and laboratory testing to predict preferred flow paths in an heterogeneous aquifer.

PubMed

Gierczak, R F D; Devlin, J F; Rudolph, D L

2006-01-05

Elevated nitrate concentrations within a municipal water supply aquifer led to pilot testing of a field-scale, in situ denitrification technology based on carbon substrate injections. In advance of the pilot test, detailed characterization of the site was undertaken. The aquifer consisted of complex, discontinuous and interstratified silt, sand and gravel units, similar to other well studied aquifers of glaciofluvial origin, 15-40 m deep. Laboratory and field tests, including a conservative tracer test, a pumping test, a borehole flowmeter test, grain-size analysis of drill cuttings and core material, and permeameter testing performed on core samples, were performed on the most productive depth range (27-40 m), and the results were compared. The velocity profiles derived from the tracer tests served as the basis for comparison with other methods. The spatial variation in K, based on grain-size analysis, using the Hazen method, were poorly correlated with the breakthrough data. Trends in relative hydraulic conductivity (K/K(avg)) from permeameter testing compared somewhat better. However, the trends in transient drawdown with depth, measured in multilevel sampling points, corresponded particularly well with those of solute mass flux. Estimates of absolute K, based on standard pumping test analysis of the multilevel drawdown data, were inversely correlated with the tracer test data. The inverse nature of the correlation was attributed to assumptions in the transient drawdown packages that were inconsistent with the variable diffusivities encountered at the scale of the measurements. Collectively, the data showed that despite a relatively low variability in K within the aquifer under study (within a factor of 3), water and solute mass fluxes were concentrated in discrete intervals that could be targeted for later bioremediation.

Sequential sampling of ribes populations in the control of white pine blister rust (Cronartium ribicola Fischer) in California

Treesearch

Harold R. Offord

1966-01-01

Sequential sampling based on a negative binomial distribution of ribes populations required less than half the time taken by regular systematic line transect sampling in a comparison test. It gave the same control decision as the regular method in 9 of 13 field trials. A computer program that permits sequential plans to be built readily for other white pine regions is...

Experimental Analysis of Propeller Interactions With a Flexible Wing Micro-Air-Vehicle

DTIC Science & Technology

2006-03-23

Wing (Freestream Only) Momentum Balance Results.............. 94 Table 10. Flexible/ Rigid Wing (Freestream and Propeller Running) Momentum Balance ...107 Table 18. Propeller/MAV Forces and Moments at 14,000 RPM ( Rigid Wing) ............ 107 Table 19. Balance Data (Raw and Corrected...velocity field around the vehicle. A limited number of tests have been performed to assess the technique in comparison to force balance data. 4

EVOLUTION OF THE MAGNETIC FIELD LINE DIFFUSION COEFFICIENT AND NON-GAUSSIAN STATISTICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snodin, A. P.; Ruffolo, D.; Matthaeus, W. H.

The magnetic field line random walk (FLRW) plays an important role in the transport of energy and particles in turbulent plasmas. For magnetic fluctuations that are transverse or almost transverse to a large-scale mean magnetic field, theories describing the FLRW usually predict asymptotic diffusion of magnetic field lines perpendicular to the mean field. Such theories often depend on the assumption that one can relate the Lagrangian and Eulerian statistics of the magnetic field via Corrsin’s hypothesis, and additionally take the distribution of magnetic field line displacements to be Gaussian. Here we take an ordinary differential equation (ODE) model with thesemore » underlying assumptions and test how well it describes the evolution of the magnetic field line diffusion coefficient in 2D+slab magnetic turbulence, by comparisons to computer simulations that do not involve such assumptions. In addition, we directly test the accuracy of the Corrsin approximation to the Lagrangian correlation. Over much of the studied parameter space we find that the ODE model is in fairly good agreement with computer simulations, in terms of both the evolution and asymptotic values of the diffusion coefficient. When there is poor agreement, we show that this can be largely attributed to the failure of Corrsin’s hypothesis rather than the assumption of Gaussian statistics of field line displacements. The degree of non-Gaussianity, which we measure in terms of the kurtosis, appears to be an indicator of how well Corrsin’s approximation works.« less

Fault Study of Valve Based on Test Analysis and Comparison

NASA Astrophysics Data System (ADS)

Cheng, Li; Yang, Wukui; Liang, Tao; Xu, Yu; Chen, Chao

2017-10-01

The valve of a certain type of small engine often has the fault phenomenon of abnormal vibration noise and can’t close under the specified pressure, which may cause the engine automatic stop because of valve incomplete close leading to fuel leakage during test and startup on the bench. By test study compared to imported valve with the same use function and test condition valve, and put forward the thinking of improving valve structure, compared no-improved valve to improved valve by adopting Fluent field simulation software. As a result, improved valve can restore close pressure of valve, restrain abnormal vibration noise phenomenon, and effectively compensate compression value of spring because of steel ball contacting position downward with valve casing.

Corona-vacuum failure mechanism test facilities

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Mueller, L. A.; Koutnik, E. A.

1975-01-01

A nondestructive corona-vacuum test facility for testing high-voltage power system components has been developed using commercially available hardware. The facility simulates operating temperature and vacuum while monitoring coronal discharges with residual gases. Corona threshold voltages obtained from statorette tests with various gas-solid dielectric systems and comparison with calculated data support the following conclusions: (1) air gives the highest corona threshold voltage and helium the lowest, with argon and helium-xenon mixtures intermediate; (2) corona threshold voltage increases with gas pressure; (3) corona threshold voltage for an armature winding can be accurately calculated by using Paschen curves for a uniform field; and (4) Paschen curves for argon can be used to calculate the corona threshold voltage in He-Xe mixtures, for which Paschen curves are unavailable.-

Serological tests for detecting Rift Valley fever viral antibodies in sheep from the Nile Delta.

PubMed Central

Scott, R M; Feinsod, F M; Allam, I H; Ksiazek, T G; Peters, C J; Botros, B A; Darwish, M A

1986-01-01

To determine the accuracy of serological methods in detecting Rift Valley fever (RVF) viral antibodies, we examined serum samples obtained from 418 sheep in the Nile Delta by using five tests. The plaque reduction neutralization test (PRNT) was considered the standard serological method against which the four other tests were compared. Twenty-four serum samples had RVF viral antibodies detected by PRNT. Hemagglutination inhibition and enzyme-linked immunosorbent assay antibodies to RVF virus were also present in the same 24 serum samples. Indirect immunofluorescence was less sensitive in comparison with PRNT, and complement fixation was the least sensitive. These results extend observations made with laboratory animals to a large field-collected group of Egyptian sheep. PMID:3533977

Short-term memory for spatial configurations in the tactile modality: a comparison with vision.

PubMed

Picard, Delphine; Monnier, Catherine

2009-11-01

This study investigates the role of acquisition constraints on the short-term retention of spatial configurations in the tactile modality in comparison with vision. It tests whether the sequential processing of information inherent to the tactile modality could account for limitation in short-term memory span for tactual-spatial information. In addition, this study investigates developmental aspects of short-term memory for tactual- and visual-spatial configurations. A total of 144 child and adult participants were assessed for their memory span in three different conditions: tactual, visual, and visual with a limited field of view. The results showed lower tactual-spatial memory span than visual-spatial, regardless of age. However, differences in memory span observed between the tactile and visual modalities vanished when the visual processing of information occurred within a limited field. These results provide evidence for an impact of acquisition constraints on the retention of spatial information in the tactile modality in both childhood and adulthood.

Industrial hemp as a potential bioenergy crop in comparison with kenaf, switchgrass and biomass sorghum.

PubMed

Das, Lalitendu; Liu, Enshi; Saeed, Areej; Williams, David W; Hu, Hongqiang; Li, Chenlin; Ray, Allison E; Shi, Jian

2017-11-01

This study takes combined field trial, lab experiment, and economic analysis approaches to evaluate the potential of industrial hemp in comparison with kenaf, switchgrass and biomass sorghum. Agronomy data suggest that the per hectare yield (5437kg) of industrial hemp stem alone was at a similar level with switchgrass and sorghum; while the hemp plants require reduced inputs. Field trial also showed that ∼1230kg/ha hemp grain can be harvested in addition to stems. Results show a predicted ethanol yield of ∼82gallons/dry ton hemp stems, which is comparable to the other three tested feedstocks. A comparative cost analysis indicates that industrial hemp could generate higher per hectare gross profit than the other crops if both hemp grains and biofuels from hemp stem were counted. These combined evaluation results demonstrate that industrial hemp has great potential to become a promising regional commodity crop for producing both biofuels and value-added products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Validation of the DIFFAL, HPAC and HotSpot Dispersion Models Using the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials Witness Plate Deposition Dataset.

PubMed

Purves, Murray; Parkes, David

2016-05-01

Three atmospheric dispersion models--DIFFAL, HPAC, and HotSpot--of differing complexities have been validated against the witness plate deposition dataset taken during the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials. The small-scale nature of these trials in comparison to many other historical radiological dispersion trials provides a unique opportunity to evaluate the near-field performance of the models considered. This paper performs validation of these models using two graphical methods of comparison: deposition contour plots and hotline profile graphs. All of the models tested are assessed to perform well, especially considering that previous model developments and validations have been focused on larger-scale scenarios. Of the models, HPAC generally produced the most accurate results, especially at locations within ∼100 m of GZ. Features present within the observed data, such as hot spots, were not well modeled by any of the codes considered. Additionally, it was found that an increase in the complexity of the meteorological data input to the models did not necessarily lead to an improvement in model accuracy; this is potentially due to the small-scale nature of the trials.

PM2.5 Technology Assessment and Characterization Study in New York - PMTACS-NY: The 2001 Summer Field Intensive in Queens, NY

NASA Astrophysics Data System (ADS)

Demerjian, K. L.

2002-12-01

In the summer of 2001, an intensive field measurement campaign was carried out in Queens, NY as part of the PM2.5 Technology Assessment and Characterization Study in New York (PMTACS-NY) to characterize the physical and chemical composition of particulate matter and related precursors utilizing conventional and advanced instrumentation technologies. The measurement program, involving a team of scientists from federal, state, university and private sector organizations, was designed to provide detailed time resolved chemical and physical characterization of the urban PM2.5/co-pollutant complex in relation to the regional environment. A summary of the chemical and meteorological data defining specific events during the field intensive is presented as are results addressing specific hypothesis designed around PMTACS-NY program objectives. These include initial findings and conclusions related to 1) performance testing and evaluation of emerging measurement technologies and comparison with EPA mandated PM federal reference methods currently operational as part of the New York State and national PM2.5 monitoring network; 2) emissions characterization of CNG, standard diesel and CRT (Continuously Regenerating Technology) diesel retrofit powered vehicles; and 3) compositional comparisons of urban and regional PM2.5.

AC loss, interstrand resistance and mechanical properties of prototype EU DEMO TF conductors up to 30 000 load cycles

NASA Astrophysics Data System (ADS)

Yagotintsev, K.; Nijhuis, A.

2018-07-01

Two prototype Nb3Sn cable-in-conduit conductors conductors were designed and manufactured for the toroidal field (TF) magnet system of the envisaged European DEMO fusion reactor. The AC loss, contact resistance and mechanical properties of two sample conductors were tested in the Twente Cryogenic Cable Press under cyclic load up to 30 000 cycles. Though both conductors were designed to operate at 82 kA in a background magnetic field of 13.6 T, they reflect different approaches with respect to the magnet winding pack assembly. The first approach is based on react and wind technology while the second is the more common wind and react technology. Each conductor was tested first for AC loss in virgin condition without handling. The impact of Lorentz load during magnet operation was simulated using the cable press. In the press each conductor specimen was subjected to transverse cyclic load up to 30 000 cycles in liquid helium bath at 4.2 K. Here a summary of results for AC loss, contact resistance, conductor deformation, mechanical heat production and conductor stiffness evolution during cycling of the load is presented. Both conductors showed similar mechanical behaviour but quite different AC loss. In comparison with previously tested ITER TF conductors, both DEMO TF conductors possess very low contact resistance resulting in high coupling loss. At the same time, load cycling has limited impact on properties of DEMO TF conductors in comparison with ITER TF conductors.

Field investigation of low-temperature cracking and stiffness moduli on selected roads with conventional and high modulus asphalt concrete

NASA Astrophysics Data System (ADS)

Judycki, Józef; Jaczewski, Mariusz; Ryś, Dawid; Pszczoła, Marek; Jaskuła, Piotr; Glinicki, Adam

2017-09-01

High Modulus Asphalt Concrete (HMAC) was introduced in Poland as a one of the solutions to the problem of rutting, type of deterioration common in the 1990s. After first encouraging trials in 2002 HMAC was widely used for heavily loaded national roads and motorways. However some concerns were raised about low-temperature cracking of HMAC. This was the main reason of the studies presented in this article were started. The article presents the comparison of performance of pavements constructed in typical contract conditions with the road bases made of HMAC and conventional asphalt concrete (AC). The field investigation was focused on the number of low-temperature cracks, bearing capacity (based on FWD test) of road sections localized in coldest region of Poland. Also load transfer efficiency of selected low-temperature cracks was assessed. FWD test confirmed lower deflections of pavements with HMAC and two times higher stiffness modulus of asphalt courses in comparison to pavements constructed with conventional AC mixtures. Relation of stiffness of asphalt layers and amount of low-temperature cracks showed that the higher stiffness modulus of asphalt layers could lead to increase of the number of low-temperature cracks. FWD test results showed that the load transfer efficiency of low-temperature cracks on pavements with HMAC presents very low values, very close to lack of load transfer. It was surprising as section with HMAC road base were aged from 2 to 5 years and presented very good bearing capacity.

Rat electropharmacograms of the flavonoids rutin and quercetin in comparison to those of moclobemide and clinically used reference drugs suggest antidepressive and/or neuroprotective action.

PubMed

Dimpfel, Wilfried

2009-04-01

In order to be able to test single constituents of herbal plant extracts with respect to possible clinical usefulness, the model of local field potential analysis leading to the so-called electropharmacogram has been successfully used in rats to classify the effects of theanine and theogallin in the past. The present investigation aims at the prediction of efficacy and possible mechanisms of action of rutin and quercetin. Adult rats (day-night converted) were instrumented with four bipolar concentric electrodes into the frontal cortex, hippocampus, striatum and reticular formation. Field potentials were recorded during a pre-drug reference period of 45 min followed by oral administration of the particular test compound and 4h recording thereafter. Data were transmitted wirelessly to the computer for spectral frequency analysis. Rutin (5-80 mg/kg) as well as quercetin (5-40 mg/kg orally) produced similar electropharmacograms with dose dependent decreases of spectral alpha2 and beta1 frequencies within all brain areas. Peak effects were reached 4h after administration. The pattern of changes approached that obtained after 2.5mg/kg of moclobemide during the first hour as revealed by discriminant analysis in comparison to a large matrix of other drugs with known clinical indications. Data suggest antidepressant capabilities for rutin and quercetin with inhibition of monoamino oxidase at least as part of the mechanism of action. Both compounds should be tested clinically in patients with symptoms of depression.

In Pursuit of LSST Science Requirements: A Comparison of Photometry Algorithms

NASA Astrophysics Data System (ADS)

Becker, Andrew C.; Silvestri, Nicole M.; Owen, Russell E.; Ivezić, Željko; Lupton, Robert H.

2007-12-01

We have developed an end-to-end photometric data-processing pipeline to compare current photometric algorithms commonly used on ground-based imaging data. This test bed is exceedingly adaptable and enables us to perform many research and development tasks, including image subtraction and co-addition, object detection and measurements, the production of photometric catalogs, and the creation and stocking of database tables with time-series information. This testing has been undertaken to evaluate existing photometry algorithms for consideration by a next-generation image-processing pipeline for the Large Synoptic Survey Telescope (LSST). We outline the results of our tests for four packages: the Sloan Digital Sky Survey's Photo package, DAOPHOT and ALLFRAME, DOPHOT, and two versions of Source Extractor (SExtractor). The ability of these algorithms to perform point-source photometry, astrometry, shape measurements, and star-galaxy separation and to measure objects at low signal-to-noise ratio is quantified. We also perform a detailed crowded-field comparison of DAOPHOT and ALLFRAME, and profile the speed and memory requirements in detail for SExtractor. We find that both DAOPHOT and Photo are able to perform aperture photometry to high enough precision to meet LSST's science requirements, and less adequately at PSF-fitting photometry. Photo performs the best at simultaneous point- and extended-source shape and brightness measurements. SExtractor is the fastest algorithm, and recent upgrades in the software yield high-quality centroid and shape measurements with little bias toward faint magnitudes. ALLFRAME yields the best photometric results in crowded fields.

Nondestructive detection and measurement of hydrogen embrittlement

DOEpatents

Alex, Franklin; Byrne, Joseph Gerald

1977-01-01

A nondestructive system and method for the determination of the presence and extent of hydrogen embrittlement in metals, alloys, and other crystalline structures subject thereto. Positron annihilation characteristics of the positron-electron annihilation within the tested material provide unique energy distribution curves for each type of material tested at each respective stage of hydrogen embrittlement. Gamma radiation resulting from such annihilation events is detected and statistically summarized by appropriate instrumentation to reveal the variations of electron activity within the tested material caused by hydrogen embrittlement therein. Such data from controlled tests provides a direct indication of the relative stages of hydrogen embrittlement in the form of unique energy distribution curves which may be utilized as calibration curves for future comparison with field tests to give on-site indication of progressive stages of hydrogen embrittlement.

Virtual navigation performance: the relationship to field of view and prior video gaming experience.

PubMed

Richardson, Anthony E; Collaer, Marcia L

2011-04-01

Two experiments examined whether learning a virtual environment was influenced by field of view and how it related to prior video gaming experience. In the first experiment, participants (42 men, 39 women; M age = 19.5 yr., SD = 1.8) performed worse on a spatial orientation task displayed with a narrow field of view in comparison to medium and wide field-of-view displays. Counter to initial hypotheses, wide field-of-view displays did not improve performance over medium displays, and this was replicated in a second experiment (30 men, 30 women; M age = 20.4 yr., SD = 1.9) presenting a more complex learning environment. Self-reported video gaming experience correlated with several spatial tasks: virtual environment pointing and tests of Judgment of Line Angle and Position, mental rotation, and Useful Field of View (with correlations between .31 and .45). When prior video gaming experience was included as a covariate, sex differences in spatial tasks disappeared.

Vapor compression heat pump system field tests at the TECH complex

NASA Astrophysics Data System (ADS)

Baxter, V. D.

1985-07-01

The Tennessee Energy Conservation In Housing (TECH) complex has been utilized since 1977 as a field test site for several novel and conventional heat pump systems for space conditioning and water heating. Systems tested include the Annual Cycle Energy System (ACES), solar assisted heat pumps (SAHP) both parallel and series, two conventional air-to-air heat pumps, an air-to-air heat pump with desuperheater water heater, and horizontal coil and multiple shallow vertical coil ground-coupled heat pumps (GCHP). A direct comparison of the measured annual performance of the test systems was not possible. However, a cursory examination revealed that the ACES had the best performance. However, its high cost makes it unlikely that it will achieve widespread use. Costs for the SAHP systems are similar to those of the ACES but their performance is not as good. Integration of water heating and space conditioning functions with a desuperheater yielded significant efficiency improvement at modest cost. The GCHP systems performed much better for heating than for cooling and may well be the most efficient alternative for residences in cold climates.

Vapor compression heat pump system field tests at the tech complex

NASA Astrophysics Data System (ADS)

Baxter, Van D.

1985-11-01

The Tennessee Energy Conservation In Housing (TECH) complex has been utilized since 1977 as a field test site for several novel and conventional heat pump systems for space conditioning and water heating. Systems tested include the Annual Cycle Energy System (ACES), solar assisted heat pumps (SAHP) both parallel and series, two conventional air-to-air heat pumps, an air-to-air heat pump with desuperheater water heater, and horizontal coil and multiple shallow vertical coil ground-coupled heat pumps (GCHP). A direct comparison of the measured annual performance of the test systems was not possible. However, a cursory examination revealed that the ACES had the best performance, however, its high cost makes it unlikely that it will achieve wide-spread use. Costs for the SAHP systems are similar to those of the ACES but their performance is not as good. Integration of water heating and space conditioning functions with a desuperheater yielded significant efficiency improvement at modest cost. The GCHP systems performed much better for heating than for cooling and may well be the most efficient alternative for residences in cold climates.

A multi-analyte biosensor for the simultaneous label-free detection of pathogens and biomarkers in point-of-need animal testing.

PubMed

Ewald, Melanie; Fechner, Peter; Gauglitz, Günter

2015-05-01

For the first time, a multi-analyte biosensor platform has been developed using the label-free 1-lambda-reflectometry technique. This platform is the first, which does not use imaging techniques, but is able to perform multi-analyte measurements. It is designed to be portable and cost-effective and therefore allows for point-of-need testing or on-site field-testing with possible applications in diagnostics. This work highlights the application possibilities of this platform in the field of animal testing, but is also relevant and transferable to human diagnostics. The performance of the platform has been evaluated using relevant reference systems like biomarker (C-reactive protein) and serology (anti-Salmonella antibodies) as well as a panel of real samples (animal sera). The comparison of the working range and limit of detection shows no loss of performance transferring the separate assays to the multi-analyte setup. Moreover, the new multi-analyte platform allows for discrimination between sera of animals infected with different Salmonella subtypes.

WE-AB-BRB-10: Filmless QA of CyberKnife MLC-Collimated and Iris-Collimated Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gersh, J; Spectrum Medical Physics, LLC, Greenville, SC

Purpose: Current methods of CK field shape QA is based on the use of radiochromic film. Though accurate results can be attained, these methods are prone to error, time consuming, and expensive. The techniques described herein perform similar QA using the FOIL Detector (Field, Output, and Image Localization). A key feature of this in-house QA solution, and central to this study, is an aSi flat-panel detector which provides the user with the means to perform accurate, immediate, and quantitative field analysis. Methods: The FOIL detector is automatically aligned in the CK beam using fiducial markers implanted within the detector case.more » Once the system is aligned, a treatment plan is delivered which irradiates the flat-panel imager using the field being tested. The current study tests each of the clinically-used fields shaped using the Iris variable-aperture collimation system using a plan which takes 6 minutes to deliver. The user is immediately provided with field diameter and beam profile, as well as a comparison to baseline values. Additionally, the detector is used to acquire and analyze leaf positions of the InCise multi-leaf collimation system. Results: Using a 6-minute plan consisting of 11 beams of 25MU-per-beam, the FOIL detector provided the user with a quantitative analysis of all clinically-used field shapes. The FOIL detector was also able to clearly resolve field edge junctions in a picket fence test, including slight over-travel of individual leaves as well as inter-leaf leakage. Conclusion: The FOIL system provided comparable field diameter and profile data when compared to methods using film; providing results much faster and with 5% of the MU used for film. When used with the MLC system, the FOIL detector provided the means for immediate quantification of the performance of the system through analysis of leaf positions in a picket fence test field. Author is the President/Owner of Spectrum Medical Physics, LLC, a company which maintains contracts with Siemens Healthcare and Standard Imaging, Inc.« less

On assessing bioequivalence and interchangeability between generics based on indirect comparisons.

PubMed

Zheng, Jiayin; Chow, Shein-Chung; Yuan, Mengdie

2017-08-30

As more and more generics become available in the market place, the safety/efficacy concerns may arise as the result of interchangeably use of approved generics. However, bioequivalence assessment for regulatory approval among generics of the innovative drug product is not required. In practice, approved generics are often used interchangeably without any mechanism of safety monitoring. In this article, based on indirect comparisons, we proposed several methods to assessing bioequivalence and interchangeability between generics. The applicability of the methods and the similarity assumptions were discussed, as well as the inappropriateness of directly adopting adjusted indirect comparison to the field of generics' comparison. Besides, some extensions were given to take into consideration the important topics in clinical trials for bioequivalence assessments, for example, multiple comparisons and simultaneously testing bioequivalence among three generics. Extensive simulation studies were conducted to investigate the performances of the proposed methods. The studies of malaria generics and HIV/AIDS generics prequalified by the WHO were used as real examples to demonstrate the use of the methods. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Research on the Conductivity-Based Detection Principles of Bubbles in Two-Phase Flows and the Design of a Bubble Sensor for CBM Wells.

PubMed

Wu, Chuan; Wen, Guojun; Han, Lei; Wu, Xiaoming

2016-09-17

The parameters of gas-liquid two-phase flow bubbles in field coalbed methane (CBM) wells are of great significance for analyzing coalbed methane output, judging faults in CBM wells, and developing gas drainage and extraction processes, which stimulates an urgent need for detecting bubble parameters for CBM wells in the field. However, existing bubble detectors cannot meet the requirements of the working environments of CBM wells. Therefore, this paper reports findings on the principles of measuring the flow pattern, velocity, and volume of two-phase flow bubbles based on conductivity, from which a new bubble sensor was designed. The structural parameters and other parameters of the sensor were then computed, the "water film phenomenon" produced by the sensor was analyzed, and the appropriate materials for making the sensor were tested and selected. After the sensor was successfully devised, laboratory tests and field tests were performed, and the test results indicated that the sensor was highly reliable and could detect the flow patterns of two-phase flows, as well as the quantities, velocities, and volumes of bubbles. With a velocity measurement error of ±5% and a volume measurement error of ±7%, the sensor can meet the requirements of field use. Finally, the characteristics and deficiencies of the bubble sensor are summarized based on an analysis of the measurement errors and a comparison of existing bubble-measuring devices and the designed sensor.

Research on the Conductivity-Based Detection Principles of Bubbles in Two-Phase Flows and the Design of a Bubble Sensor for CBM Wells

PubMed Central

Wu, Chuan; Wen, Guojun; Han, Lei; Wu, Xiaoming

2016-01-01

The parameters of gas-liquid two-phase flow bubbles in field coalbed methane (CBM) wells are of great significance for analyzing coalbed methane output, judging faults in CBM wells, and developing gas drainage and extraction processes, which stimulates an urgent need for detecting bubble parameters for CBM wells in the field. However, existing bubble detectors cannot meet the requirements of the working environments of CBM wells. Therefore, this paper reports findings on the principles of measuring the flow pattern, velocity, and volume of two-phase flow bubbles based on conductivity, from which a new bubble sensor was designed. The structural parameters and other parameters of the sensor were then computed, the “water film phenomenon” produced by the sensor was analyzed, and the appropriate materials for making the sensor were tested and selected. After the sensor was successfully devised, laboratory tests and field tests were performed, and the test results indicated that the sensor was highly reliable and could detect the flow patterns of two-phase flows, as well as the quantities, velocities, and volumes of bubbles. With a velocity measurement error of ±5% and a volume measurement error of ±7%, the sensor can meet the requirements of field use. Finally, the characteristics and deficiencies of the bubble sensor are summarized based on an analysis of the measurement errors and a comparison of existing bubble-measuring devices and the designed sensor. PMID:27649206

Effect of moderate magnetic annealing on the microstructure, quasi-static and viscoelastic mechanical behavior of a structural epoxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tehrani, Mehran; Al-Haik, Marwan; Garmestani, Hamid

2012-01-01

In this study the effect of moderate magnetic fields on the microstructure of a structural epoxy system was investigated. The changes in the microstructure have been quantitatively investigated using wide angle x-ray diffraction (WAXD) and pole figure analysis. The mechanical properties (modulus, hardness and strain rate sensitivity parameter) of the epoxy system annealed in the magnetic field were probed with the aid of instrumented nanoindentation and the results are compared to the reference epoxy sample. To further examine the creep response of the magnetically annealed and reference samples, short 45 min duration creep tests were carried out. An equivalent tomore » the macro scale creep compliance was calculated using the aforementioned nano-creep data. Using the continuous complex compliance (CCC) analysis, the phase lag angle, tan (δ), between the displacement and applied force in an oscillatory nanoindentation test was measured for both neat and magnetically annealed systems through which the effect of low magnetic fields on the viscoelastic properties of the epoxy was invoked. The comparison of the creep strain rate sensitivity parameter , A/d(0), from short term(80 ), creep tests and the creep compliance J(t) from the long term(2700 s) creep tests with the tan(δ) suggests that former parameter is a more useful comparative creep parameter than the creep compliance. The results of this investigation reveal that under low magnetic fields both the quasi-static and viscoelastic mechanical properties of the epoxy have been improved.« less

Closed-loop adaptive optic comparison between a Shack-Hartmann and a distorted grating wavefront sensor

NASA Astrophysics Data System (ADS)

Harrison, Paul; Erry, Gavin R. G.; Otten, Leonard J.; Cuevas, Desirae M.; Weaver, Lawrence D.

2004-11-01

Earlier research reported a comparison of the wavefronts recorded simultaneously by a Shack-Hartmann and a Distorted Grating Wavefront Sensor (DGWFS). In this paper we present the results of a continuation of this earlier work where we have now closed an adaptive optics loop under simulated propagation conditions using the Advanced Concept Laboratory (ACL) at Lincoln Laboratory. For these measurements only one wavefront sensor controlled the deformable mirror at a time. To make direct comparisons between the sensors we took advantage of the ACL's ability to exactly replicate a time varying propagation simulation. Time varying and static comparisons of the two sensors controlling the ACL adaptive system under conditions that ranged from a benign path, D/r0 = 2, to a propagation condition with significant scintillation, D/r0 =9, will be shown using the corrected far field spot as a measure of performance. The paper includes a description of the DGWFS used for these tests and describes the procedure used to align and calibrate the sensor.

Closed-loop adaptive optic comparison between a Shack-Hartmann and a distorted-grating wavefront sensor

NASA Astrophysics Data System (ADS)

Harrison, Paul; Erry, Gavin R. G.; Otten, Leonard J., III; Cuevas, D. M.; Weaver, Lawrence D.

2004-02-01

Earlier research reported a comparison of the wavefronts recorded simultaneously by a Shack-Hartmann and a Distorted Grating Wavefront Sensor (DGWFS). In this paper we present the results of a continuation of this earlier work where we have now closed an adaptive optics loop under simulated propagation conditions using the Advanced Concept Laboratory (ACL) at Lincoln Laboratory. For these measurements only one wavefront sensor controlled the deformable mirror at a time. To make direct comparisons between the sensors we took advantage of the ACL"s ability to exactly replicate a time varying propagation simulation. Time varying and static comparisons of the two sensors controlling the ACL adaptive system under conditions that ranged from a benign path, D/r0 = 2, to a propagation condition with significant scintillation, D/r0 =9, will be shown using the corrected far field spot as a measure of performance. The paper includes a description of the DGWFS used for these tests and describes the procedure used to align and calibrate the sensor.

Calculation of electromagnetic fields induced on a geostationary satellite by an electrostatic discharge

NASA Astrophysics Data System (ADS)

Froger, E.; Marque, J. P.

The electromagnetic response of an orbiting satellite to an electrostatic discharge is compared to that of the same object subjected (in a susceptibility test) to an injection current. In the absence of actual data, the comparison was performed on the basis of two numerical simulations: one using the GEODE particle code for the orbiting case, and the other using the ALICE code for a representative injection configuration. It is found that the evolution of the electromagnetic fields is controlled in particular by the particle emission rhythm, giving rise to an ejection flux 'slit' whose rise time is about several tens of nanoseconds.

Fast gravity, gravity partials, normalized gravity, gravity gradient torque and magnetic field: Derivation, code and data

NASA Technical Reports Server (NTRS)

Gottlieb, Robert G.

1993-01-01

Derivation of first and second partials of the gravitational potential is given in both normalized and unnormalized form. Two different recursion formulas are considered. Derivation of a general gravity gradient torque algorithm which uses the second partial of the gravitational potential is given. Derivation of the geomagnetic field vector is given in a form that closely mimics the gravitational algorithm. Ada code for all algorithms that precomputes all possible data is given. Test cases comparing the new algorithms with previous data are given, as well as speed comparisons showing the relative efficiencies of the new algorithms.

Telescope Multi-Field Wavefront Control with a Kalman Filter

NASA Technical Reports Server (NTRS)

Lou, John Z.; Redding, David; Sigrist, Norbert; Basinger, Scott

2008-01-01

An effective multi-field wavefront control (WFC) approach is demonstrated for an actuated, segmented space telescope using wavefront measurements at the exit pupil, and the optical and computational implications of this approach are discussed. The integration of a Kalman Filter as an optical state estimator into the wavefront control process to further improve the robustness of the optical alignment of the telescope will also be discussed. Through a comparison of WFC performances between on-orbit and ground-test optical system configurations, the connection (and a possible disconnection) between WFC and optical system alignment under these circumstances are analyzed. Our MACOS-based computer simulation results will be presented and discussed.

Experimental and computational surface and flow-field results for an all-body hypersonic aircraft

NASA Technical Reports Server (NTRS)

Lockman, William K.; Lawrence, Scott L.; Cleary, Joseph W.

1990-01-01

The objective of the present investigation is to establish a benchmark experimental data base for a generic hypersonic vehicle shape for validation and/or calibration of advanced computational fluid dynamics computer codes. This paper includes results from the comprehensive test program conducted in the NASA/Ames 3.5-foot Hypersonic Wind Tunnel for a generic all-body hypersonic aircraft model. Experimental and computational results on flow visualization, surface pressures, surface convective heat transfer, and pitot-pressure flow-field surveys are presented. Comparisons of the experimental results with computational results from an upwind parabolized Navier-Stokes code developed at Ames demonstrate the capabilities of this code.

A survey of the broadband shock associated noise prediction methods

NASA Technical Reports Server (NTRS)

Kim, Chan M.; Krejsa, Eugene A.; Khavaran, Abbas

1992-01-01

Several different prediction methods to estimate the broadband shock associated noise of a supersonic jet are introduced and compared with experimental data at various test conditions. The nozzle geometries considered for comparison include a convergent and a convergent-divergent nozzle, both axisymmetric. Capabilities and limitations of prediction methods in incorporating the two nozzle geometries, flight effect, and temperature effect are discussed. Predicted noise field shows the best agreement for a convergent nozzle geometry under static conditions. Predicted results for nozzles in flight show larger discrepancies from data and more dependable flight data are required for further comparison. Qualitative effects of jet temperature, as observed in experiment, are reproduced in predicted results.

Investigation of the Representation of OLEs and Terrain Effects Within the Costal Zone in the EDMF Parameterization Scheme: An Airborne Doppler Wind Lidar Perspective

DTIC Science & Technology

2014-10-20

have received several versions of the EDMF from Joao Teixeira for testing . RESULTS Most of the results of our last year’s research effort were...as a comparison to the ABL over cold water. Note that the MATERHORN was co-funded by ONR (Ferek). As this research has progressed, we have added a...transports. Emmitt and de Wekker are using the WRF and COAMPs models to test out sensitivities to changes in the EDMF related to our field data. We

Measurements of pressures on the wing of an aircraft model during steady rotation

NASA Technical Reports Server (NTRS)

Martin, Colin A.; Gage, Peter J.; Hultberg, Randy S.; Bowman, James S., Jr.

1990-01-01

An investigation has been conducted in the Spin Tunnel Facility at the NASA Langley Research Center to measure the pressures on the wing surfaces of a model of a Basic Training Aircraft during steady rotation. The tests were made to determine the nature of the wing pressure distribution during rotations typical of spin entry and steady spin. Comparisons are made between the forces and moments obtained from integrating the pressure field with those measured directly during rotary balance force tests. The results are also compared with estimates determined from a simple numerical model of the wing aerodynamic forces.

Comparison of contraction times of a muscle and its motor units

NASA Technical Reports Server (NTRS)

Eldred, E.; Smith, L.; Edgerton, V. R.

1992-01-01

The twitch contraction time (CT) for each of 13 soleus (SOL) and 13 medial gastrocnemius (MG) muscles was compared with the mean CT from a sample of its motor units (MUs; 356 total) to see if the CT of a whole muscle when tested at its optimal length (Lo) differed systematically from that of its MUs tested at their individual Lo's. The CTs of the whole muscle were significantly longer in the ratio of 1.13. This is consistent with a hypothesis that electrical-field effects result in a more protracted contraction of the individual muscle fiber.

Vestibular ontogeny: Measuring the influence of the dynamic environment

NASA Technical Reports Server (NTRS)

Jones, Timothy A.; Devries, Sherri M.; Dubois, Linda M.; Nelson, Rick C.

1993-01-01

In comparison to other special senses, we are only meagerly informed about the development of vestibular function and the mechanisms that may operate to control or influence the course of vestibular ontogeny. Perhaps one contributing factor to this disparity is the difficulty of evaluating vestibular sense organs directly and noninvasively. The present report describes a recently developed direct noninvasive vestibular function test that can be used to address many basic questions about the developing vestibular system. More particularly, the test can be used to examine the effects of the dynamic environment (e.g. gravitational field and vibration) on vestibular ontogeny.

Comparison between design and installed acoustic characteristics of NASA Lewis 9- by 15-foot low-speed wind tunnel acoustic treatment

NASA Technical Reports Server (NTRS)

Dahl, Milo D.; Woodward, Richard P.

1990-01-01

The test section of the NASA Lewis 9- by 15-Foot Low-Speed Wind Tunnel was acoustically treated to allow the measurement of sound under simulated free-field conditions. The treatment was designed for high sound absorption at frequencies above 250 Hz and for withstanding the environmental conditions in the test section. In order to achieve the design requirements, a fibrous, bulk-absorber material was packed into removable panel sections. Each section was divided into two equal-depth layers packed with material to different bulk densities. The lower density was next to the facing of the treatment. The facing consisted of a perforated plate and screening material layered together. Sample tests for normal-incidence acoustic absorption were also conducted in an impedance tube to provide data to aid in the treatment design. Tests with no airflow, involving the measurement of the absorptive properties of the treatment installed in the 9- by 15-foot wind tunnel test section, combined the use of time-delay spectrometry with a previously established free-field measurement method. This new application of time-delay spectrometry enabled these free-field measurements to be made in nonanechoic conditions. The results showed that the installed acoustic treatment had absorption coefficients greater than 0.95 over the frequency range 250 Hz to 4 kHz. The measurements in the wind tunnel were in good agreement with both the analytical prediction and the impedance tube test data.

Comparison of chemiluminescence methods for analysis of hydrogen peroxide and hydroxyl radicals

NASA Astrophysics Data System (ADS)

Pehrman, R.; Amme, M.; Cachoir, C.

2006-01-01

Assessment of alpha radiolysis influence on the chemistry of geologically disposed spent fuel demands analytical methods for radiolytic product determination at trace levels. Several chemiluminescence methods for the detection of radiolytic oxidants hydrogen peroxide and hydroxyl radicals are tested. Two of hydrogen peroxide methods use luminol, catalyzed by either μ-peroxidase or hemin, one uses 10-methyl-9-(p-formylphenyl)-acridinium carboxylate trifluoromethanesulfonate and one potassium periodate. All recipes are tested as batch systems in basic conditions. For hydroxyl radical detection luminophores selected are 3-hydroxyphthalic hydrazide and rutin. Both methods are tested as batch systems. The results are compared and the applicability of the methods for near-field dissolution studies is discussed.

Polar Ozone Loss Rates: Comparison Of Match Observations With Simulations Of 3-D Chemical Transport Model And Box Model

NASA Astrophysics Data System (ADS)

Tripathi, O. P.; Godin-Beekmann, S.; Lefevre, F.; Marchand, M.; Pazmino, A.; Hauchecorne, A.

2005-12-01

Model simulations of ozone loss rates during recent arctic and Antarctic winters are compared with the observed ozone loss rates from the match technique. Arctic winters 1994/1995, 1999/2000, 2002/2003 and the Antarctic winter 2003 were considered for the analysis. We use a high resolution chemical transport model MIMOSA-CHIM and REPROBUS box model for the calculation of ozone loss rates. Trajectory model calculations show that the ozone loss rates are dependent on the initialization fields. On the one hand when chemical fields are initialized by UCAM (University of Cambridge SLIMCAT model simulated fields) the loss rates were underestimated by a factor of two whereas on the other hand when it is initialized by UL (University of Leeds) fields the model loss rates are in a very good agreement with match loss rates at lower levels. The study shows a very good agreement between MIMOSA-CHIM simulation and match observation in 1999/2000 winter at both levels, 450 and 500 K, except slight underestimation in March at 500 K. But in January we have a very good agreement. This is also true for 1994/1995 when we consider simulated ozone loss rate in view of the ECMWF wind deficiency assuming that match observations were not made on isolated trajectories. Sensitivity tests, by changing JCl2O2 value, particle number density and heating rates, performed for the arctic winter 1999/2000 shows that we need to improve our understanding of particle number density and heating rate calculation mechanism. Burkholder JCl2O2 has improved the comparison of MIMOSA-CHIM model results with observations (Tripathi et al., 2005). In the same study the comparison results were shown to improved by changing heating rates and number density through NAT particle sedimentation.

Use of TRMM Rainfall Information in Improving Long-Term, Satellite-Based Global Precipitation Analyses

NASA Technical Reports Server (NTRS)

Starr, David OC. (Technical Monitor); Adler, Robert F.; Huffman, George; Curtis, Scott; Bolvin, David; Nelkin, Eric

2002-01-01

The TRMM rainfall products are inter-compared among themselves and to the 23 year, monthly, globally complete precipitation analysis of the World Climate Research Program's (WCRP/ GEWEX) Global Precipitation Climatology Project (GPCP). Ways in which the TRMM-based estimates can be used to improve the long-term data set are described. These include improvement of the passive microwave algorithm that is applied to the 15 year SSM/I record and calibration or adjustment of the current GPCP fields utilizing the 4-5 year overlap of TRMM and GPCP. A comparison of the GPCP monthly surface precipitation fields and the TRMM-based multi-satellite analyses indicates that the two are similar, but have significant differences that relate to the different input data sets. Although on a zonal average basis over the ocean the two analyses are similar in the deep Tropics, there are subtle differences between the eastern and western Pacific Ocean in the relative magnitudes. In mid-latitudes the GPCP has somewhat larger mean precipitation than TRMM. Statistical comparisons of TRMM and GPCP monthly fields are carried out in terms of histogram matching for both ocean and land regions and for small areas to diagnose differences. These comparisons form the basis for a TRMM calibration of the GPCP fields using matched histograms over regional areas as a function of season. Although final application of this procedure will likely await the Version 6 of the TRMM products, tests using Version 5 are shown that provide a TRMM-calibrated GPCP version that will produce an improved climatology and a more accurate month-to-month precipitation analysis for the last 20 years.

Analysis of Developing Gas/liquid Two-Phase Flows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elena A. Tselishcheva; Michael Z. Podowski; Steven P. Antal

The goal of this work is to develop a mechanistically based CFD model that can be used to simulate process equipment operating in the churn-turbulent regime. The simulations were performed using a state-of-the-art computational multiphase fluid dynamics code, NPHASE–CMFD [Antal et al,2000]. A complete four-field model, including the continuous liquid field and three dispersed gas fields representing bubbles of different sizes, was first carefully tested for numerical convergence and accuracy, and then used to reproduce the experimental results from the TOPFLOW test facility at Forschungszentrum Dresden-Rossendorf e.V. Institute of Safety Research [Prasser et al,2007]. Good progress has been made inmore » simulating the churn-turbulent flows and comparison the NPHASE-CMFD simulations with TOPFLOW experimental data. The main objective of the paper is to demonstrate capability to predict the evolution of adiabatic churn-turbulent gas/liquid flows. The proposed modelling concept uses transport equations for the continuous liquid field and for dispersed bubble fields [Tselishcheva et al, 2009]. Along with closure laws based on interaction between bubbles and continuous liquid, the effect of height on air density has been included in the model. The figure below presents the developing flow results of the study, namely total void fraction at different axial locations along the TOPFLOW facility test section. The complete model description, as well as results of simulations and validation will be presented in the full paper.« less

CFD Simulations of the Supersonic Inflatable Aerodynamic Decelerator (SIAD) Ballistic Range Tests

NASA Technical Reports Server (NTRS)

Brock, Joseph; Stern, Eric; Wilder, Michael

2017-01-01

A series of ballistic range tests were performed on a scaled model of the Supersonic Flight Demonstration Test (SFDT) intended to test the Supersonic Inflatable Aerodynamic Decelerator (SIAD) geometry. The purpose of these experiments were to provide aerodynamic coefficients of the vehicle to aid in mission and vehicle design. The experimental data spans the moderate Mach number range, $3.8-2.0$, with a total angle of attack ($alpha_T$) range, $10o-20o$. These conditions are intended to span the Mach-$alpha$ space for the majority of the SFDT experiment. In an effort to validate the predictive capabilities of Computational Fluid Dynamics (CFD) for free-flight aerodynamic behavior, numerical simulations of the ballistic range experiment are performed using the unstructured finite volume Navier-Stokes solver, US3D. Comparisons to raw vehicle attitude, and post-processed aerodynamic coefficients are made between simulated results and experimental data. The resulting comparisons for both raw model attitude and derived aerodynamic coefficients show good agreement with experimental results. Additionally, near body pressure field values for each trajectory simulated are investigated. Extracted surface and wake pressure data gives further insights into dynamic flow coupling leading to a potential mechanism for dynamic instability.

Ares I-X Flight Evaluation Tasks in Support of Ares I Development

NASA Technical Reports Server (NTRS)

Huebner, Lawrence D.; Richards, James S.; Coates, Ralph H., III; Cruit, Wendy D.; Ramsey, Matthew N.

2010-01-01

NASA s Constellation Program successfully launched the Ares I-X Flight Test Vehicle on October 28, 2009. The Ares I-X flight was a development flight test that offered a unique opportunity for early engineering data to impact the design and development of the Ares I crew launch vehicle. As the primary customer for flight data from the Ares I-X mission, the Ares Projects Office established a set of 33 flight evaluation tasks to correlate fight results with prospective design assumptions and models. Included within these tasks were direct comparisons of flight data with pre-flight predictions and post-flight assessments utilizing models and modeling techniques being applied to design and develop Ares I. A discussion of the similarities and differences in those comparisons and the need for discipline-level model updates based upon those comparisons form the substance of this paper. The benefits of development flight testing were made evident by implementing these tasks that used Ares I-X data to partially validate tools and methodologies in technical disciplines that will ultimately influence the design and development of Ares I and future launch vehicles. The areas in which partial validation from the flight test was most significant included flight control system algorithms to predict liftoff clearance, ascent, and stage separation; structural models from rollout to separation; thermal models that have been updated based on these data; pyroshock attenuation; and the ability to predict complex flow fields during time-varying conditions including plume interactions.

Thermal/structural modeling of a large scale in situ overtest experiment for defense high level waste at the Waste Isolation Pilot Plant Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan, H.S.; Stone, C.M.; Krieg, R.D.

Several large scale in situ experiments in bedded salt formations are currently underway at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, USA. In these experiments, the thermal and creep responses of salt around several different underground room configurations are being measured. Data from the tests are to be compared to thermal and structural responses predicted in pretest reference calculations. The purpose of these comparisons is to evaluate computational models developed from laboratory data prior to fielding of the in situ experiments. In this paper, the computational models used in the pretest reference calculation for one of themore » large scale tests, The Overtest for Defense High Level Waste, are described; and the pretest computed thermal and structural responses are compared to early data from the experiment. The comparisons indicate that computed and measured temperatures for the test agree to within ten percent but that measured deformation rates are between two and three times greater than corresponsing computed rates. 10 figs., 3 tabs.« less

Aeroacoustics of advanced propellers

NASA Technical Reports Server (NTRS)

Groeneweg, John F.

1990-01-01

The aeroacoustics of advanced, high speed propellers (propfans) are reviewed from the perspective of NASA research conducted in support of the Advanced Turboprop Program. Aerodynamic and acoustic components of prediction methods for near and far field noise are summarized for both single and counterrotation propellers in uninstalled and configurations. Experimental results from tests at both takeoff/approach and cruise conditions are reviewed with emphasis on: (1) single and counterrotation model tests in the NASA Lewis 9 by 15 (low speed) and 8 by 6 (high speed) wind tunnels, and (2) full scale flight tests of a 9 ft (2.74 m) diameter single rotation wing mounted tractor and a 11.7 ft (3.57 m) diameter counterrotation aft mounted pusher propeller. Comparisons of model data projected to flight with full scale flight data show good agreement validating the scale model wind tunnel approach. Likewise, comparisons of measured and predicted noise level show excellent agreement for both single and counterrotation propellers. Progress in describing angle of attack and installation effects is also summarized. Finally, the aeroacoustic issues associated with ducted propellers (very high bypass fans) are discussed.

The NASA Ames Hypersonic Combustor-Model Inlet CFD Simulations and Experimental Comparisons

NASA Technical Reports Server (NTRS)

Venkatapathy, E.; Tokarcik-Polsky, S.; Deiwert, G. S.; Edwards, Thomas A. (Technical Monitor)

1995-01-01

Computations have been performed on a three-dimensional inlet associated with the NASA Ames combustor model for the hypersonic propulsion experiment in the 16-inch shock tunnel. The 3-dimensional inlet was designed to have the combustor inlet flow nearly two-dimensional and of sufficient mass flow necessary for combustion. The 16-inch shock tunnel experiment is a short duration test with test time of the order of milliseconds. The flow through the inlet is in chemical non-equilibrium. Two test entries have been completed and limited experimental results for the inlet region of the combustor-model are available. A number of CFD simulations, with various levels of simplifications such as 2-D simulations, 3-D simulations with and without chemical reactions, simulations with and without turbulent conditions, etc., have been performed. These simulations have helped determine the model inlet flow characteristics and the important factors that affect the combustor inlet flow and the sensitivity of the flow field to these simplifications. In the proposed paper, CFD modeling of the hypersonic inlet, results from the simulations and comparison with available experimental results will be presented.

Experimental evaluation of the magnetic properties of commercially available magnetic microspheres.

PubMed

Connolly, Joan; St Pierre, Timothy G; Dobson, Jon

2005-01-01

The magnetic properties of 5 commercially available magnetic microsphere samples are tested and compared with those stated by their manufacturers. A suspension of magnetic, iron oxide nanoparticles is studied for comparison. Two of the microsphere samples have magnetic properties which do not support the manufacturer's claims of superparamagnetism. The remaining 3 microsphere samples as well as the nanoparticle suspension are superparamagnetic or ferromagnetic as claimed by the manufacturers. Field cooled and zero field cooled magnetisations indicate that the non-superparamagnetic microsphere samples contain blocked magnetic particles at room temperature. This observation is supported by the open hysteresis loops of the room temperature, field dependent magnetisation measurement. There is a significant paramagnetic component in the superparamagnetic microspheres. This is also present to a lesser extent in a nanoparticle suspension.

Methods to Prove 20+ Year Life of CPV Products (in less than 20 Years)

NASA Astrophysics Data System (ADS)

Bowman, John; Spencer, Mark

2011-12-01

Due to the long term life expectations of photovoltaic products and the short duration of most introduced CPV technologies, it is critical for CPV companies to carefully construct field trials to prove product life. Because of the complicated geometric, thermal, and spectral characteristics of CPV systems, conducting very precise power output measurements reproducibly over many months is very difficult. Robust normalization methods specific to the exact optical system and PV cell type must be developed. Once the performance over a specific duration, e.g. one year, is established, then some justification is required to extrapolate to future performance. Comparisons to accelerated test results provide this justification. SolFocus has been conducting field trials of the SF-1100S CPV system for over two years. These field trials consist of controlled populations of SF-1100P modules, operating in grid-tied systems, which have been repeatedly measured at the individual module level over the duration of the trials. In this paper, field data will be presented along with normalization methodology and statistical methods for determining power degradation slope distributions for populations of individual modules. These results will be correlated with accelerated field tests which have been ongoing for 1.5 years and are estimated to be equivalent to 10 to 15 years of non-accelerated operation.

Evaluation of the attractive force of different types of new-generation magnetic attachment systems.

PubMed

Akin, Hakan; Coskun, M Emre; Akin, E Gulsah; Ozdemir, A Kemal

2011-03-01

Rare earth magnets have been used in prosthodontics, but their tendency for corrosion in the oral cavity and insufficient attractive forces limit long-term clinical application. The purpose of this study was to evaluate the attractive force of different types of new-generation magnetic attachment systems. The attractive force of the neodymium-iron-boron (Nd-Fe-B) and samarium-cobalt (Sm-Co) magnetic attachment systems, including closed-field (Hilop and Hicorex) and open-field (Dyna and Steco) systems, was measured in a universal testing machine (n=5). The data were statistically evaluated with 1-way ANOVA and post hoc Tukey-Kramer multiple comparison test (α=.05). The closed-field systems exhibited greater (P<.001) attractive force than the open-field systems. Moreover, there was a statistically significant difference in attractive force between Nd-Fe-B and Sm-Co magnets (P<.001). The strongest attractive force was found with the Hilop system (9.2 N), and the lowest force was found with the Steco system (2.3 N). The new generation of Nd-Fe-B closed-field magnets, along with improved technology, provides sufficient denture retention for clinical application. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Comparison of aquifer characterization approaches through steady state groundwater model validation: A controlled laboratory sandbox study

USGS Publications Warehouse

Illman, W.A.; Zhu, J.; Craig, A.J.; Yin, D.

2010-01-01

Groundwater modeling has become a vital component to water supply and contaminant transport investigations. An important component of groundwater modeling under steady state conditions is selecting a representative hydraulic conductivity (K) estimate or set of estimates which defines the K field of the studied region. Currently, there are a number of characterization approaches to obtain K at various scales and in varying degrees of detail, but there is a paucity of information in terms of which characterization approach best predicts flow through aquifers or drawdowns caused by some drawdown inducing events. The main objective of this paper is to assess K estimates obtained by various approaches by predicting drawdowns from independent cross-hole pumping tests and total flow rates through a synthetic heterogeneous aquifer from flow-through tests. Specifically, we (1) characterize a synthetic heterogeneous aquifer built in the sandbox through various techniques (permeameter analyses of core samples, single-hole, cross-hole, and flow-through testing), (2) obtain mean K fields through traditional analysis of test data by treating the medium to be homogeneous, (3) obtain heterogeneous K fields through kriging and steady state hydraulic tomography, and (4) conduct forward simulations of 16 independent pumping tests and six flowthrough tests using these homogeneous and heterogeneous K fields and comparing them to actual data. Results show that the mean K and heterogeneous K fields estimated through kriging of small-scale K data (core and single-hole tests) yield biased predictions of drawdowns and flow rates in this synthetic heterogeneous aquifer. In contrast, the heterogeneous K distribution or ?K tomogram? estimated via steady state hydraulic tomography yields excellent predictions of drawdowns of pumping tests not used in the construction of the tomogram and very good estimates of total flow rates from the flowthrough tests. These results suggest that steady state groundwater model validation is possible in this laboratory sandbox aquifer if the heterogeneous K distribution and forcing functions (boundary conditions and source/sink terms) are characterized sufficiently. ?? 2010 by the American Geophysical Union.

Planned versus actual outcomes as a result of animal feeding operation decisions for managing phosphorus.

PubMed

Cabot, Perry E; Nowak, Pete

2005-01-01

The paper explores how decisions made on animal feeding operations (AFOs) influence the management of manure and phosphorus. Variability among these decisions from operation to operation and from field to field can influence the validity of nutrient loss risk assessments. These assessments are based on assumptions that the decision outcomes regarding manure distribution will occur as they are planned. The discrepancy between planned versus actual outcomes in phosphorus management was explored on nine AFOs managing a contiguous set of 210 fields in south-central Wisconsin. A total of 2611 soil samples were collected and multiple interviews conducted to assign phosphorus index (PI) ratings to the fields. Spearman's rank correlation coefficients (r(S)) indicated that PI ratings were less sensitive to soil test phosphorus (STP) levels (r(S) = 0.378), universal soil loss equation (USLE) (r(S) = 0.261), ratings for chemical fertilizer application (r(S) = 0.185), and runoff class (r(S) = -0.089), and more sensitive to ratings for manure application (r(S) = 0.854). One-way ANOVA indicated that mean field STP levels were more homogenous than field PI ratings between AFOs. Kolmogorov-Smirnov (K-S) tests displayed several nonsignificant comparisons for cumulative distribution functions, S(x), of mean STP levels on AFO fields. On the other hand, the K-S tests of S(x) for PI ratings indicated that the majority of these S(x) functions were significantly different between AFOs at or greater than the 0.05 significance level. Interviews suggested multiple reasons for divergence between planned and actual outcomes in managing phosphorus, and that this divergence arises at the strategic, tactical, and operational levels of decision-making.

Performance comparison for Barnes model 12-1000, Exotech model 100, and Ideas Inc. Biometer Mark 2

NASA Technical Reports Server (NTRS)

Robinson, B. (Principal Investigator)

1981-01-01

Results of tests show that all channels of all instruments, except channel 3 of the Biometer Mark 2, were stable in response to input signals were linear, and were adequately stable in response to temperature changes. The Biometer Mark 2 is labelled with an inappropriate description of the units measured and the dynamic range is a inappropriate for field measurements causing unnecessarily high fractional errors. This instrument is, therefore, quantization limited. The dynamic range and noise performance of the Model 12-1000 are appropriate for remote sensing field research. The field of view and performance of the Model 100A and the Model 12-1000 are satisfactory. The Biometer Mark 2 has not, as yet, been satisfactorily equipped with an acceptable field of view determining device. Neither the widely used aperture plate nor the 24 deg cone are acceptable.

Statistical power comparisons at 3T and 7T with a GO / NOGO task.

PubMed

Torrisi, Salvatore; Chen, Gang; Glen, Daniel; Bandettini, Peter A; Baker, Chris I; Reynolds, Richard; Yen-Ting Liu, Jeffrey; Leshin, Joseph; Balderston, Nicholas; Grillon, Christian; Ernst, Monique

2018-07-15

The field of cognitive neuroscience is weighing evidence about whether to move from standard field strength to ultra-high field (UHF). The present study contributes to the evidence by comparing a cognitive neuroscience paradigm at 3 Tesla (3T) and 7 Tesla (7T). The goal was to test and demonstrate the practical effects of field strength on a standard GO/NOGO task using accessible preprocessing and analysis tools. Two independent matched healthy samples (N = 31 each) were analyzed at 3T and 7T. Results show gains at 7T in statistical strength, the detection of smaller effects and group-level power. With an increased availability of UHF scanners, these gains may be exploited by cognitive neuroscientists and other neuroimaging researchers to develop more efficient or comprehensive experimental designs and, given the same sample size, achieve greater statistical power at 7T. Published by Elsevier Inc.

Assessment of bifacial photovoltaic module power rating methodologies–inside and out

DOE PAGES

Deline, Chris; MacAlpine, Sara; Marion, Bill; ...

2017-01-26

One-sun power ratings for bifacial modules are currently undefined. This is partly because there is no standard definition of rear irradiance given 1000 W·m -2 on the front. Using field measurements and simulations, we evaluate multiple deployment scenarios for bifacial modules and provide details on the amount of irradiance that could be expected. A simplified case that represents a single module deployed under conditions consistent with existing one-sun irradiance standards lead to a bifacial reference condition of 1000 W·m -2 G front and 130-140 W·m -2 G rear. For fielded systems of bifacial modules, Grear magnitude and spatial uniformity willmore » be affected by self-shade from adjacent modules, varied ground cover, and ground-clearance height. A standard measurement procedure for bifacial modules is also currently undefined. A proposed international standard is under development, which provides the motivation for this paper. Here, we compare field measurements of bifacial modules under natural illumination with proposed indoor test methods, where irradiance is only applied to one side at a time. The indoor method has multiple advantages, including controlled and repeatable irradiance and thermal environment, along with allowing the use of conventional single-sided flash test equipment. The comparison results are promising, showing that indoor and outdoor methods agree within 1%-2% for multiple rear-irradiance conditions and bifacial module construction. Furthermore, a comparison with single-diode theory also shows good agreement to indoor measurements, within 1%-2% for power and other current-voltage curve parameters.« less

Selection of surrogate bacteria in place of E. coli O157:H7 and Salmonella Typhimurium for pulsed electric field treatment of orange juice.

PubMed

Gurtler, Joshua B; Rivera, Rebecca B; Zhang, Howard Q; Geveke, David J

2010-04-30

Pulsed electric field (PEF) technology has been used for the inactivation of microorganisms and to prevent flavor loss in liquid foods and beverages in place of thermal pasteurization. When used to pasteurize orange juice, PEF may prevent loss of volatile sensory attributes. Enterohemorrhagic E. coli O157:H7 (EHEC), two strains of Salmonella Typhimurium, and twenty strains of non-pathogenic bacteria were screened for inactivation in orange juice by PEF at 22 and 20kV/cm at 45 and 55 degrees C, respectively. Higher populations of both salmonellae were inactivated (2.81 and 3.54 log CFU/ml) at 55 degrees C, in comparison with the reduction of EHEC (2.22 log). When tested under the same conditions, inactivation of EHEC was slightly greater than that of a non-pathogenic E. coli (NPEC) ATCC 35218 (2.02 log). NPEC was further tested as a surrogate for EHEC by comparing inactivation kinetics at 45, 50 and 55 degrees C at field strengths of between 7.86 and 32.55kV/cm. Statistical comparison of revealed that EHEC and NPEC inactivation curves were homogeneous at outlet temperatures of 45 and 50 degrees C; however, EHEC was slightly more sensitive to PEF than the surrogate NPEC at 55 degrees C. The higher PEF resistance of non-pathogenic E. coli 35218 at 55 degrees C may provide a desirable margin of safety when used in pilot plant challenge studies in place of E. coli O157:H7. Published by Elsevier B.V.

Validation of Vehicle Panel/Equipment Response from Diffuse Acoustic Field Excitation Using Spatially Correlated Transfer Function Approach

NASA Technical Reports Server (NTRS)

Smith, Andrew; LaVerde, Bruce; Fulcher, Clay; Hunt, Ron

2012-01-01

An approach for predicting the vibration, strain, and force responses of a flight-like vehicle panel assembly to acoustic pressures is presented. Important validation for the approach is provided by comparison to ground test measurements in a reverberant chamber. The test article and the corresponding analytical model were assembled in several configurations to demonstrate the suitability of the approach for response predictions when the vehicle panel is integrated with equipment. Critical choices in the analysis necessary for convergence of the predicted and measured responses are illustrated through sensitivity studies. The methodology includes representation of spatial correlation of the pressure field over the panel surface. Therefore, it is possible to demonstrate the effects of hydrodynamic coincidence in the response. The sensitivity to pressure patch density clearly illustrates the onset of coincidence effects on the panel response predictions.

Field Testing of an Unvented Roof with Fibrous Insulation, Tiles, and Vapor Diffusion Venting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ueno, K.; Lstiburek, J. W.

This research is a test implementation of an unvented tile roof assembly in a hot-humid climate (Orlando, FL; Zone 2A), insulated with air permeable insulation (netted and blown fiberglass). Given the localized moisture accumulation and failures seen in previous unvented roof field work, it was theorized that a 'diffusion vent' (water vapor open, but air barrier 'closed') at the highest points in the roof assembly might allow for the wintertime release of moisture, to safe levels. The 'diffusion vent' is an open slot at the ridge and hips, covered with a water-resistant but vapor open (500+ perm) air barrier membrane.more » As a control comparison, one portion of the roof was constructed as a typical unvented roof (self-adhered membrane at ridge). The data collected to date indicate that the diffusion vent roof shows greater moisture safety than the conventional, unvented roof design.« less

Sonic environment of aircraft structure immersed in a supersonic jet flow stream

NASA Technical Reports Server (NTRS)

Guinn, W. A.; Balena, F. J.; Soovere, J.

1976-01-01

Test methods for determining the sonic environment of aircraft structure that is immersed in the flow stream of a high velocity jet or that is subjected to the noise field surrounding the jet, were investigated. Sonic environment test data measured on a SCAT 15-F model in the flow field of Mach 1.5 and 2.5 jets were processed. Narrow band, lateral cross correlation and noise contour plots are presented. Data acquisition and reduction methods are depicted. A computer program for scaling the model data is given that accounts for model size, jet velocity, transducer size, and jet density. Comparisons of scaled model data and full size aircraft data are made for the L-1011, S-3A, and a V/STOL lower surface blowing concept. Sonic environment predictions are made for an engine-over-the-wing SST configuration.

Unsteady loads due to propulsive lift configurations. Part A: Investigation of scaling laws

NASA Technical Reports Server (NTRS)

Morton, J. B.; Haviland, J. K.

1978-01-01

This study covered scaling laws, and pressure measurements made to determine details of the large scale jet structure and to verify scaling laws by direct comparison. The basis of comparison was a test facility at NASA Langley in which a JT-15D exhausted over a boilerplater airfoil surface to reproduce upper surface blowing conditions. A quarter scale model was built of this facility, using cold jets. A comparison between full scale and model pressure coefficient spectra, presented as functions of Strouhal numbers, showed fair agreement, however, a shift of spectral peaks was noted. This was not believed to be due to Mach number or Reynolds number effects, but did appear to be traceable to discrepancies in jet temperatures. A correction for jet temperature was then tried, similar to one used for far field noise prediction. This was found to correct the spectral peak discrepancy.

A comparison of a coaxial focused laser Doppler system in atmospheric measurements

NASA Technical Reports Server (NTRS)

Karaki, S.

1973-01-01

Measurements of atmospheric velocities and turbulence with the laser Doppler system were obtained, and the results compared with cup anemometer and hot-wire measurements in the same wind field. The laser Doppler velocimeter (LDV) is described along with the test procedures. It was found that mean values determined from the LDV data are within 5% of other anemometer data for long time periods, and the LDV measures higher velocities.

Mutual Coupling of Internal Transmit/Receive Pair in Launch Vehicle Fairing Model Using WIPL-D

NASA Technical Reports Server (NTRS)

Trout, Dawn H.; Stanley, James E.; Wahid, Parveen F.

2011-01-01

Evaluating the fairing Radio Frequency (RF) Environment within the launch vehicle payload fairing cavity due to internal transmitters is an issue for the spacecraft and launch vehicle industry. This paper provides an effective approach for launch vehicle fairing evaluation of power reception and field distribution due to internal transmitters. A commercial electromagnetic computational tool, WIPL-D is applied in this study for test data comparison.

Comparison of Sample and Detection Quantification Methods for Salmonella Enterica from Produce

NASA Technical Reports Server (NTRS)

Hummerick, M. P.; Khodadad, C.; Richards, J. T.; Dixit, A.; Spencer, L. M.; Larson, B.; Parrish, C., II; Birmele, M.; Wheeler, Raymond

2014-01-01

The purpose of this study was to identify and optimize fast and reliable sampling and detection methods for the identification of pathogens that may be present on produce grown in small vegetable production units on the International Space Station (ISS), thus a field setting. Microbiological testing is necessary before astronauts are allowed to consume produce grown on ISS where currently there are two vegetable production units deployed, Lada and Veggie.

Turbofan aft duct suppressor study. Contractor's data report of mode probe signal data

NASA Technical Reports Server (NTRS)

Fiske, G. H.; Motsinger, R. E.; Syed, A. A.; Joshi, M. C.; Kraft, R. E.

1983-01-01

Acoustic modal distributions were measured in a fan test model having an annular exhaust duct for comparison with theoretically predicted acoustic suppression values. This report contains the amplitude and phase data of the acoustic signals sensed by the transducers of the two mode probes employed in the measurement. Each mode probe consisted of an array of 12 transducers sensing the acoustic field at three axial positions and four radial positions.

Comparison of two reconfigurable N×N interconnects for a recurrent neural network

NASA Astrophysics Data System (ADS)

Berger, Christoph; Collings, Neil; Pourzand, Ali R.; Volkel, Reinnard

1996-11-01

Two different methods of pattern replication (conventional and interlaced fan-out) have been investigated and experimentally tested in a reconfigurable 5X5 optical interconnect. Similar alignment problems due to imaging errors (field curvature) were observed in both systems. We conclude that of the two methods the interlaced fan-out is better suited to avoid these imaging errors, to reduce system size and to implement an optical feedback loop.

Field evaluation of the biolarvicide, spinosad 20 per cent emulsifiable concentrate in comparison to its 12 per cent suspension concentrate formulation against Culex quinquefasciatus, the vector of bancroftian filariasis in India.

PubMed

Sadanandane, Candasamy; Gunasekaran, Kasinathan; Boopathi Doss, Ponnusamy Sivagnana; Jambulingam, Purushothaman

2018-01-01

Biolarvicides may offer alternatives to chemical larvicides as these are known to be safe to environment and selective against the target species. However, only a limited number of biolarvicides have been approved for mosquito larval control. In the current study, a new formulation of spinosad, 20 per cent emulsifiable concentrate (EC) was tested for its efficacy against Culex quinquefasciatus, in comparison to its 12 per cent suspension concentrate (SC). Spinosad 20 per cent EC was tested against Cx. quinquefasciatus immature at 25, 50, 100 and 150 mg active ingredient (ai)/m [2] in cesspits, drains and abandoned wells in comparison with spinosad 12 per cent SC at the optimum field application dosage of 50 mg ai/m [2] . The 20 per cent EC caused 90-100 per cent reduction of pupal density for 7-14 days in cesspits, 10-17 days in drains and 14-30 days in abandoned wells at all dosages tested. At lower dosages of 25 and 50 mg ai/m [2] , >90 per cent reduction of pupal density was observed for one week in cesspits and street drains and for two weeks in abandoned wells. The effective duration of control provided by the higher dosages, 100 and 150 mg ai/m [2] was 1.4 to 2 times greater than the lower dosages, 25 and 50 mg ai/m [2] . The findings showed that the spinosad 20 per cent EC can be used for larval control against Cx. quinquefasciatus, at the dosage of 25 mg ai/m [2] at weekly interval in cesspits and drains and at fortnightly interval in abandoned wells. Spinosad 20 per cent EC could be one of the options to be considered for larval control under integrated vector management.

Test target for characterizing 3D resolution of optical coherence tomography

NASA Astrophysics Data System (ADS)

Hu, Zhixiong; Hao, Bingtao; Liu, Wenli; Hong, Baoyu; Li, Jiao

2014-12-01

Optical coherence tomography (OCT) is a non-invasive 3D imaging technology which has been applied or investigated in many diagnostic fields including ophthalmology, dermatology, dentistry, cardiovasology, endoscopy, brain imaging and so on. Optical resolution is an important characteristic that can describe the quality and utility of an image acquiring system. We employ 3D printing technology to design and fabricate a test target for characterizing 3D resolution of optical coherence tomography. The test target which mimics USAF 1951 test chart was produced with photopolymer. By measuring the 3D test target, axial resolution as well as lateral resolution of a spectral domain OCT system was evaluated. For comparison, conventional microscope and surface profiler were employed to characterize the 3D test targets. The results demonstrate that the 3D resolution test targets have the potential of qualitatively and quantitatively validating the performance of OCT systems.

Three-dimensional geostatistical inversion of flowmeter and pumping test data.

PubMed

Li, Wei; Englert, Andreas; Cirpka, Olaf A; Vereecken, Harry

2008-01-01

We jointly invert field data of flowmeter and multiple pumping tests in fully screened wells to estimate hydraulic conductivity using a geostatistical method. We use the steady-state drawdowns of pumping tests and the discharge profiles of flowmeter tests as our data in the inference. The discharge profiles need not be converted to absolute hydraulic conductivities. Consequently, we do not need measurements of depth-averaged hydraulic conductivity at well locations. The flowmeter profiles contain information about relative vertical distributions of hydraulic conductivity, while drawdown measurements of pumping tests provide information about horizontal fluctuation of the depth-averaged hydraulic conductivity. We apply the method to data obtained at the Krauthausen test site of the Forschungszentrum Jülich, Germany. The resulting estimate of our joint three-dimensional (3D) geostatistical inversion shows an improved 3D structure in comparison to the inversion of pumping test data only.

Radiation calculation in non-equilibrium shock layer

NASA Astrophysics Data System (ADS)

Dubois, Joanne

2005-05-01

The purpose of the work was to investigate confidence in radiation predictions on an entry probe body in high temperature conditions taking the Huygens probe as an example. Existing engineering flowfield codes for shock tube and blunt body simulations were used and updated when necessary to compute species molar fractions and flow field parameters. An interface to the PARADE radiation code allowed radiative emission estimates to the body surface to be made. A validation of the radiative models in equilibrium conditions was first made with published data and by comparison with shock tube test case data from the IUSTI TCM2 facility with Titan like atmosphere test gas. Further verifications were made in non-equilibrium with published computations. These comparisons were initially made using a Boltzmann assumption for the electronic states of CN. An attempt was also made to use pseudo species for the individual electronic states of CN. Assumptions made in this analysis are described and a further comparison with shock tube data undertaken. Several CN radiation datasets have been used, and while improvements to the modelling tools have been made, it seems that considerable uncertainty remains in the modelling of the non-equilibrium emission using simple engineering methods.

Incremental Aerodynamic Coefficient Database for the USA2

NASA Technical Reports Server (NTRS)

Richardson, Annie Catherine

2016-01-01

In March through May of 2016, a wind tunnel test was conducted by the Aerosciences Branch (EV33) to visually study the unsteady aerodynamic behavior over multiple transition geometries for the Universal Stage Adapter 2 (USA2) in the MSFC Aerodynamic Research Facility's Trisonic Wind Tunnel (TWT). The purpose of the test was to make a qualitative comparison of the transonic flow field in order to provide a recommended minimum transition radius for manufacturing. Additionally, 6 Degree of Freedom force and moment data for each configuration tested was acquired in order to determine the geometric effects on the longitudinal aerodynamic coefficients (Normal Force, Axial Force, and Pitching Moment). In order to make a quantitative comparison of the aerodynamic effects of the USA2 transition geometry, the aerodynamic coefficient data collected during the test was parsed and incorporated into a database for each USA2 configuration tested. An incremental aerodynamic coefficient database was then developed using the generated databases for each USA2 geometry as a function of Mach number and angle of attack. The final USA2 coefficient increments will be applied to the aerodynamic coefficients of the baseline geometry to adjust the Space Launch System (SLS) integrated launch vehicle force and moment database based on the transition geometry of the USA2.

Tests of Convection Electric Field Models For The January 10, 1997, Geomagnetic Storm

NASA Astrophysics Data System (ADS)

Jordanova, V.; Boonsiriseth, A.; Thorne, R.; Dotan, Y.

The January 10-11, 1997, geomagnetic storm was caused by the passage at Earth of a magnetic cloud with a negative to positive Bz variation extending for 1 day. The ge- omagnetic indices had values of minimum Dst=-83 nT and maximum Kp=6 during the period of southward IMF within the cloud. We simulate ring current development during this storm using our kinetic drift-loss model and compare the results inferred from Volland-Stern type, Weimer, and AMIE convection electric field models. A pen- etration electric field is added to the AMIE model [Boonsiriseth et al., 2001] in order to improve the agreement with measurements from the electric field instrument on Po- lar spacecraft. The ionospheric electric potentials are mapped to the equatorial plane using the Tsyganenko 1996 magnetic field model and the resulting equatorial poten- tial models are coupled with our ring current model. While the temporal evolution of the large-scale features is similar in all three convection models, detailed comparison indicates that AMIE model shows highly variable small-scale features not present in the Volland-Stern or Weimer convection models. Results from our kinetic ring current model are compared with energetic particle data from the HYDRA, TIMAS, IPS, and CAMMICE instruments on Polar to test the applicability of the convection electric field models for this storm period.

Reward loss and the basolateral amygdala: A function in reward comparisons.

PubMed

Kawasaki, Katsuyoshi; Annicchiarico, Iván; Glueck, Amanda C; Morón, Ignacio; Papini, Mauricio R

2017-07-28

The neural circuitry underlying behavior in reward loss situations is poorly understood. We considered two such situations: reward devaluation (from large to small rewards) and reward omission (from large rewards to no rewards). There is evidence that the central nucleus of the amygdala (CeA) plays a role in the negative emotion accompanying reward loss. However, little is known about the function of the basolateral nucleus (BLA) in reward loss. Two hypotheses of BLA function in reward loss, negative emotion and reward comparisons, were tested in an experiment involving pretraining excitotoxic BLA lesions followed by training in four tasks: consummatory successive negative contrast (cSNC), autoshaping (AS) acquisition and extinction, anticipatory negative contrast (ANC), and open field testing (OF). Cell counts in the BLA (but not in the CeA) were significantly lower in animals with lesions vs. shams. BLA lesions eliminated cSNC and ANC, and accelerated extinction of lever pressing in AS. BLA lesions had no effect on OF testing: higher activity in the periphery than in the central area. This pattern of results provides support for the hypothesis that BLA neurons are important for reward comparison. The three affected tasks (cSNC, ANC, and AS extinction) involve reward comparisons. However, ANC does not seem to involve negative emotions and it was affected, whereas OF activity is known to involve negative emotion, but it was not affected. It is hypothesized that a circuit involving the thalamus, insular cortex, and BLA is critically involved in the mechanism comparing current and expected rewards. Copyright © 2017 Elsevier B.V. All rights reserved.

Simplified behaviors from increased heterogeneity: II. 3-D uranium transport at the decimeter scale and intertank comparisons.

PubMed

Miller, Andrew W; Rodriguez, Derrick R; Honeyman, Bruce D

2013-05-01

Upscaling from bench scale systems to field scale systems incorporates physical and chemical heterogeneities from atomistic up to field scales. Heterogeneities of intermediate scale (~10(-1) m) are impossible to incorporate in a bench scale experiment. To transcend these scale discrepancies, this second in a pair of papers presents results from an intermediate scale, 3-D tank experiment completed using five different particle sizes of uranium contaminated sediment from a former uranium mill field site. The external dimensions of the tank were 2.44 m×0.61 m×0.61 m (L×H×W). The five particle sizes were packed in a heterogeneous manner using roughly 11 cm cubes. Small groundwater wells were installed for spatial characterization of chemical gradients and flow parameters. An approximately six month long bromide tracer test was used for flow field characterization. Within the flow domain, local uranium breakthrough curves exhibited a wide range of behaviors. However, the global effluent breakthrough curve was smooth, and not unlike breakthrough curves observed in column scale experiments. This paper concludes with an inter-tank comparison of all three experimental systems presented in this pair of papers. Although there is a wide range of chemical and physical variability between the three tanks, major chemical constituent behaviors are often quite similar or even identical. Copyright © 2013 Elsevier B.V. All rights reserved.

Three-dimensional imaging of aquifer and aquitard heterogeneity via transient hydraulic tomography at a highly heterogeneous field site

NASA Astrophysics Data System (ADS)

Zhao, Zhanfeng; Illman, Walter A.

2018-04-01

Previous studies have shown that geostatistics-based transient hydraulic tomography (THT) is robust for subsurface heterogeneity characterization through the joint inverse modeling of multiple pumping tests. However, the hydraulic conductivity (K) and specific storage (Ss) estimates can be smooth or even erroneous for areas where pumping/observation densities are low. This renders the imaging of interlayer and intralayer heterogeneity of highly contrasting materials including their unit boundaries difficult. In this study, we further test the performance of THT by utilizing existing and newly collected pumping test data of longer durations that showed drawdown responses in both aquifer and aquitard units at a field site underlain by a highly heterogeneous glaciofluvial deposit. The robust performance of the THT is highlighted through the comparison of different degrees of model parameterization including: (1) the effective parameter approach; (2) the geological zonation approach relying on borehole logs; and (3) the geostatistical inversion approach considering different prior information (with/without geological data). Results reveal that the simultaneous analysis of eight pumping tests with the geostatistical inverse model yields the best results in terms of model calibration and validation. We also find that the joint interpretation of long-term drawdown data from aquifer and aquitard units is necessary in mapping their full heterogeneous patterns including intralayer variabilities. Moreover, as geological data are included as prior information in the geostatistics-based THT analysis, the estimated K values increasingly reflect the vertical distribution patterns of permeameter-estimated K in both aquifer and aquitard units. Finally, the comparison of various THT approaches reveals that differences in the estimated K and Ss tomograms result in significantly different transient drawdown predictions at observation ports.

Test-retest reliability and concurrent validity of a web-based questionnaire measuring workstation and individual correlates of work postures during computer work.

PubMed

IJmker, Stefan; Mikkers, Janneke; Blatter, Birgitte M; van der Beek, Allard J; van Mechelen, Willem; Bongers, Paulien M

2008-11-01

"Ergonomic" questionnaires are widely used in epidemiological field studies to study the association between workstation characteristics, work posture and musculoskeletal disorders among office workers. Findings have been inconsistent regarding the putative adverse effect of work postures. Underestimation of the true association might be present in studies due to misclassification of subjects to risk (i.e. exposed to non-neutral working postures) and no-risk categories (i.e. not exposed to non-neutral working postures) based on questionnaire responses. The objective of this study was to estimate the amount of misclassification resulting from the use of questionnaires. Test-retest reliability and concurrent validity of a newly developed questionnaire was assessed. This questionnaire collects data on workstation characteristics and on individual characteristics during computer work (i.e. work postures, movements and habits). Pictures were added where possible to provide visual guidance. The study population consisted of 84 office workers of a research department. They filled out the questionnaire on the Internet twice, with an in-between period of 2 weeks. For a subgroup of workers (n=38), additional on-site observations and multiple manual goniometer measurements were performed. Percentage agreement ranged between 71% and 100% for the test-retest analysis, between 31% and 100% for the comparison between questionnaire and on-site observation, and between 26% and 71% for the comparison between questionnaire and manual goniometer measurements. For 9 out of 12 tested items, the percentage agreement between questionnaire and manual goniometer measurements was below 50%. The questionnaire collects reliable data on workstation characteristics and some individual characteristics during computer work (i.e. work movements and habits), but does not seem to be useful to collect data on work postures during computer work in epidemiological field studies among office workers.

Comparison of a Flow Assay for Brucellosis Antibodies with the Reference cELISA Test in West African Bos indicus

PubMed Central

Bronsvoort, Barend M. deC.; Koterwas, Bronwyn; Land, Fiona; Handel, Ian G.; Tucker, James; Morgan, Kenton L.; Tanya, Vincent N.; Abdoel, Theresia H.; Smits, Henk L.

2009-01-01

Brucellosis is considered by the Food and Agricultural Organisation and the World Health Organisation as one of the most widespread zoonoses in the world. It is a major veterinary public health challenge as animals are almost exclusively the source of infection for people. It is often undiagnosed in both human patients and the animal sources and it is widely acknowledged that the epidemiology of brucellosis in humans and animals is poorly understood, particularly in sub-Saharan Africa. It is therefore important to develop better diagnostic tools in order to improve our understanding of the epidemiology and also for use in the field for disease control and eradication. As with any new diagnostic test, it is essential that it is validated in as many populations as possible in order to characterise its performance and improve the interpretation of its results. This paper describes a comparison between a new lateral flow assasy (LFA) for bovine brucellosis and the widely used cELISA in a no gold standard analysis to estimate test performance in this West African cattle population. A Bayesian formulation of the Hui-Walter latent class model incorporated previous studies' data on sensitivity and specificity of the cELISA. The results indicate that the new LFA is very sensitive (∼87%) and highly specific (∼97%). The analysis also suggests that the current cut-off of the cELSIA may not be optimal for this cattle population but alternative cut-offs did not significantly change the estimates of the LFA. This study demonstrates the potential usefulness of this simple to use test in field based surveillance and control which could be easily adopted for use in developing countries with only basic laboratory facilities. PMID:19381332

Validation of operant social motivation paradigms using BTBR T+tf/J and C57BL/6J inbred mouse strains

PubMed Central

Martin, Loren; Sample, Hannah; Gregg, Michael; Wood, Caleb

2014-01-01

Background As purported causal factors are identified for autism spectrum disorder (ASD), new assays are needed to better phenotype animal models designed to explore these factors. With recent evidence suggesting that deficits in social motivation are at the core of ASD behavior, the development of quantitative measures of social motivation is particularly important. The goal of our study was to develop and validate novel assays to quantitatively measure social motivation in mice. Methods In order to test the validity of our paradigms, we compared the BTBR strain, with documented social deficits, to the prosocial C57BL/6J strain. Two novel conditioning paradigms were developed that allowed the test mouse to control access to a social partner. In the social motivation task, the test mice lever pressed for a social reward. The reward contingency was set on a progressive ratio of reinforcement and the number of lever presses achieved in the final trial of a testing session (breakpoint) was used as an index of social motivation. In the valence comparison task, motivation for a food reward was compared to a social reward. We also explored activity, social affiliation, and preference for social novelty through a series of tasks using an ANY-Maze video-tracking system in an open-field arena. Results BTBR mice had significantly lower breakpoints in the social motivation paradigm than C57BL/6J mice. However, the valence comparison task revealed that BTBR mice also made significantly fewer lever presses for a food reward. Conclusions The results of the conditioning paradigms suggest that the BTBR strain has an overall deficit in motivated behavior. Furthermore, the results of the open-field observations may suggest that social differences in the BTBR strain are anxiety induced. PMID:25328850

Validation of operant social motivation paradigms using BTBR T+tf/J and C57BL/6J inbred mouse strains.

PubMed

Martin, Loren; Sample, Hannah; Gregg, Michael; Wood, Caleb

2014-09-01

As purported causal factors are identified for autism spectrum disorder (ASD), new assays are needed to better phenotype animal models designed to explore these factors. With recent evidence suggesting that deficits in social motivation are at the core of ASD behavior, the development of quantitative measures of social motivation is particularly important. The goal of our study was to develop and validate novel assays to quantitatively measure social motivation in mice. In order to test the validity of our paradigms, we compared the BTBR strain, with documented social deficits, to the prosocial C57BL/6J strain. Two novel conditioning paradigms were developed that allowed the test mouse to control access to a social partner. In the social motivation task, the test mice lever pressed for a social reward. The reward contingency was set on a progressive ratio of reinforcement and the number of lever presses achieved in the final trial of a testing session (breakpoint) was used as an index of social motivation. In the valence comparison task, motivation for a food reward was compared to a social reward. We also explored activity, social affiliation, and preference for social novelty through a series of tasks using an ANY-Maze video-tracking system in an open-field arena. BTBR mice had significantly lower breakpoints in the social motivation paradigm than C57BL/6J mice. However, the valence comparison task revealed that BTBR mice also made significantly fewer lever presses for a food reward. The results of the conditioning paradigms suggest that the BTBR strain has an overall deficit in motivated behavior. Furthermore, the results of the open-field observations may suggest that social differences in the BTBR strain are anxiety induced.

Can weighing lysimeter ET represent surrounding field ET well enough to test flux station measurements of daily and sub-daily ET?

NASA Astrophysics Data System (ADS)

Evett, Steven R.; Schwartz, Robert C.; Howell, Terry A.; Louis Baumhardt, R.; Copeland, Karen S.

2012-12-01

Weighing lysimeters and neutron probes (NP) are both used to determine the change in soil water storage needed to solve for evapotranspiration (ET) using the soil water balance equation. We compared irrigated cotton ET determined using two large (3 × 3 × 2.4-m deep) weighing lysimeters and eight NP soil water profiles located outside the lysimeters in cotton fields during the BEAREX08 field campaign (see [16] Evett et al., 2012). The objectives were to (i) determine if lysimeter-based ET fluxes were representative of those from the fields, designated NE and SE, in which the lysimeters were centered, and (ii) investigate different methods of computing the soil water balance using NP data. Field fluxes were determined from the soil water balance using neutron probe measurements of change in profile water content storage. Fluxes of ET from the SE lysimeter were representative of those from the field throughout the season and can be used with reasonable certainty for comparisons of ET fluxes and energy balance closure derived from Bowen ratio (BR) and eddy covariance (EC) measurements whose footprints lay in the SE field. Comparisons of ET fluxes from EC and BR systems to those from the NE lysimeter should consider that NE lysimeter fluxes were up to 18% larger than those from the NE field during the period of rapid vegetative growth. This was due to plants on the lysimeter having greater height and width than those in the field. Nevertheless, the data from this and companion studies documents substantial underestimation of crop ET by EC stations under the conditions of BEAREX08. Comparison of zero flux plane (ZFP) and simple soil water balance methods of calculating ET from NP data showed them to be equivalent in this study; and for the ZFP method, the depth of the control volume should be determined by the depth at which the hydraulic gradient reverses, not by the depth of calculated minimum flux. If supported by a sufficiently dense and widespread network of deep soil water balance based estimates of ET in the surrounding patch and by ancillary measurements of crop stand and growth within the lysimeter and in the surrounding patch, a weighing lysimeter can provide accurate ET ground truth for comparisons with ET estimated using flux stations or ET calculated using satellite imagery. It must be emphasized that the water balance measurements must include soil profile water content measurements to well below (e.g., 0.5 to 1 m below) the root zone in order to close the water balance.

Shuttle Return-to-Flight IH-108 Aerothermal Test at CUBRC - Flow Field Calibration and CFD

NASA Technical Reports Server (NTRS)

Lau, Kei Y.; Holden, Michael

2010-01-01

This paper discusses one specific aspect of the Shuttle Retrun-To-Flight IH-108 Aerothermal Test at CUBRC, the test flow field calibration. It showed the versatility of the CUBRC LENS II wind tunnel for an aerothermal test with unique and demanding requirements. CFD analyses were used effectively to extend the test range at the low end of the Mach range. It demonstrated how ground test facility and CFD synergy can be utilitzed iteratively to enhance the confidence in the fedility of both tools. It addressed the lingering concerns of the aerothermal community on use of inpulse facility and CFD analysis. At the conclusion of the test program, members from the NASA Marshall (MSFC), CUBRC and USA (United Space Alliance) Consultants (The Grey Beards) were asked to independently verify the flight scaling data generated by Boeing for flight certification of the re-designed external tank (ET) components. The blind test comparison showed very good results. A more comprehensive discussion of the topics in this paper can be found in Chapter 6 of Reference [1]. The overall aspect of the test program has been discussed in an AIAA paper by Tim Wadhams [2]. The Shuttle Ascent Stack performance and related issues discussed in the Report [1] are not included in this paper. No ITAR data is included in this paper.

Accuracy Test of the OPLS-AA Force Field for Calculating Free Energies of Mixing and Comparison with PAC-MAC

PubMed Central

2017-01-01

We have calculated the excess free energy of mixing of 1053 binary mixtures with the OPLS-AA force field using two different methods: thermodynamic integration (TI) of molecular dynamics simulations and the Pair Configuration to Molecular Activity Coefficient (PAC-MAC) method. PAC-MAC is a force field based quasi-chemical method for predicting miscibility properties of various binary mixtures. The TI calculations yield a root mean squared error (RMSE) compared to experimental data of 0.132 kBT (0.37 kJ/mol). PAC-MAC shows a RMSE of 0.151 kBT with a calculation speed being potentially 1.0 × 104 times greater than TI. OPLS-AA force field parameters are optimized using PAC-MAC based on vapor–liquid equilibrium data, instead of enthalpies of vaporization or densities. The RMSE of PAC-MAC is reduced to 0.099 kBT by optimizing 50 force field parameters. The resulting OPLS-PM force field has a comparable accuracy as the OPLS-AA force field in the calculation of mixing free energies using TI. PMID:28418655

Electric-field distribution near rectangular microstrip radiators for hyperthermia heating: theory versus experiment in water.

PubMed

Underwood, H R; Peterson, A F; Magin, R L

1992-02-01

A rectangular microstrip antenna radiator is investigated for its near-zone radiation characteristics in water. Calculations of a cavity model theory are compared with the electric-field measurements of a miniature nonperturbing diode-dipole E-field probe whose 3 mm tip was positioned by an automatic three-axis scanning system. These comparisons have implications for the use of microstrip antennas in a multielement microwave hyperthermia applicator. Half-wavelength rectangular microstrip patches were designed to radiate in water at 915 MHz. Both low (epsilon r = 10) and high (epsilon r = 85) dielectric constant substrates were tested. Normal and tangential components of the near-zone radiated electric field were discriminated by appropriate orientation of the E-field probe. Low normal to transverse electric-field ratios at 3.0 cm depth indicate that the radiators may be useful for hyperthermia heating with an intervening water bolus. Electric-field pattern addition from a three-element linear array of these elements in water indicates that phase and amplitude adjustment can achieve some limited control over the distribution of radiated power.

WIND VELOCITIES AND SAND FLUXES IN MESQUITE DUNE-LANDS IN THE NORTHERN CHIHUAHUAN DESERT: A COMPARISON BETWEEN FIELD MEASUREMENTS AND THE QUIC (QUICK URBAN AND INDUSTRIAL COMPLEX) MODEL

EPA Science Inventory

The poster shows comparisons of wind velocities and sand fluxes between field measurements and a computer model, called QUIC (Quick Urban & Industrial Complex). The comparisons were made for a small desert region in New Mexico.

Development and On-Field Testing of Low-Cost Portable System for Monitoring PM2.5 Concentrations.

PubMed

N Genikomsakis, Konstantinos; Galatoulas, Nikolaos-Fivos; I Dallas, Panagiotis; Candanedo Ibarra, Luis Miguel; Margaritis, Dimitris; S Ioakimidis, Christos

2018-04-01

Recent developments in the field of low-cost sensors enable the design and implementation of compact, inexpensive and portable sensing units for air pollution monitoring with fine-detailed spatial and temporal resolution, in order to support applications of wider interest in the area of intelligent transportation systems (ITS). In this context, the present work advances the concept of developing a low-cost portable air pollution monitoring system (APMS) for measuring the concentrations of particulate matter (PM), in particular fine particles with a diameter of 2.5 μm or less (PM2.5). Specifically, this paper presents the on-field testing of the proposed low-cost APMS implementation using roadside measurements from a mobile laboratory equipped with a calibrated instrument as the basis of comparison and showcases its accuracy on characterizing the PM2.5 concentrations on 1 min resolution in an on-road trial. Moreover, it demonstrates the intended application of collecting fine-grained spatio-temporal PM2.5 profiles by mounting the developed APMS on an electric bike as a case study in the city of Mons, Belgium.

Development and On-Field Testing of Low-Cost Portable System for Monitoring PM2.5 Concentrations

PubMed Central

Galatoulas, Nikolaos-Fivos; I. Dallas, Panagiotis; Candanedo Ibarra, Luis Miguel; Margaritis, Dimitris; S. Ioakimidis, Christos

2018-01-01

Recent developments in the field of low-cost sensors enable the design and implementation of compact, inexpensive and portable sensing units for air pollution monitoring with fine-detailed spatial and temporal resolution, in order to support applications of wider interest in the area of intelligent transportation systems (ITS). In this context, the present work advances the concept of developing a low-cost portable air pollution monitoring system (APMS) for measuring the concentrations of particulate matter (PM), in particular fine particles with a diameter of 2.5 μm or less (PM2.5). Specifically, this paper presents the on-field testing of the proposed low-cost APMS implementation using roadside measurements from a mobile laboratory equipped with a calibrated instrument as the basis of comparison and showcases its accuracy on characterizing the PM2.5 concentrations on 1 min resolution in an on-road trial. Moreover, it demonstrates the intended application of collecting fine-grained spatio-temporal PM2.5 profiles by mounting the developed APMS on an electric bike as a case study in the city of Mons, Belgium. PMID:29614770

Testing neoclassical competitive market theory in the field.

PubMed

List, John A

2002-11-26

This study presents results from a pilot field experiment that tests predictions of competitive market theory. A major advantage of this particular field experimental design is that my laboratory is the marketplace: subjects are engaged in buying, selling, and trading activities whether I run an exchange experiment or am a passive observer. In this sense, I am gathering data in a natural environment while still maintaining the necessary control to execute a clean comparison between treatments. The main results of the study fall into two categories. First, the competitive model predicts reasonably well in some market treatments: the expected price and quantity levels are approximated in many market rounds. Second, the data suggest that market composition is important: buyer and seller experience levels impact not only the distribution of rents but also the overall level of rents captured. An unexpected result in this regard is that average market efficiency is lowest in markets that match experienced buyers and experienced sellers and highest when experienced buyers engage in bargaining with inexperienced sellers. Together, these results suggest that both market experience and market composition play an important role in the equilibrium discovery process.

Near-Field Acoustic Power Level Analysis of F31/A31 Open Rotor Model at Simulated Cruise Conditions, Technical Report II

NASA Technical Reports Server (NTRS)

Sree, Dave

2015-01-01

Near-field acoustic power level analysis of F31A31 open rotor model has been performed to determine its noise characteristics at simulated cruise flight conditions. The non-proprietary parts of the test data obtained from experiments in the 8x6 supersonic wind tunnel were provided by NASA-Glenn Research Center. The tone and broadband components of total noise have been separated from raw test data by using a new data analysis tool. Results in terms of sound pressure levels, acoustic power levels, and their variations with rotor speed, freestream Mach number, and input shaft power, with different blade-pitch setting angles at simulated cruise flight conditions, are presented and discussed. Empirical equations relating models acoustic power level and input shaft power have been developed. The near-field acoustic efficiency of the model at simulated cruise conditions is also determined. It is hoped that the results presented in this work will serve as a database for comparison and improvement of other open rotor blade designs and also for validating open rotor noise prediction codes.

An Optimal Deconvolution Method for Reconstructing Pneumatically Distorted Near-Field Sonic Boom Pressure Measurements

NASA Technical Reports Server (NTRS)

Whitmore, Stephen A.; Haering, Edward A., Jr.; Ehernberger, L. J.

1996-01-01

In-flight measurements of the SR-71 near-field sonic boom were obtained by an F-16XL airplane at flightpath separation distances from 40 to 740 ft. Twenty-two signatures were obtained from Mach 1.60 to Mach 1.84 and altitudes from 47,600 to 49,150 ft. The shock wave signatures were measured by the total and static sensors on the F-16XL noseboo. These near-field signature measurements were distorted by pneumatic attenuation in the pitot-static sensors and accounting for their effects using optimal deconvolution. Measurement system magnitude and phase characteristics were determined from ground-based step-response tests and extrapolated to flight conditions using analytical models. Deconvolution was implemented using Fourier transform methods. Comparisons of the shock wave signatures reconstructed from the total and static pressure data are presented. The good agreement achieved gives confidence of the quality of the reconstruction analysis. although originally developed to reconstruct the sonic boom signatures from SR-71 sonic boom flight tests, the methods presented here generally apply to other types of highly attenuated or distorted pneumatic measurements.

A study of the structural-acoustic response and interior noise levels of fuselage structures

NASA Technical Reports Server (NTRS)

Koval, L. R.

1978-01-01

Models of both flat and curved fuselage panels were tested for their sound transmission characteristics. The effect of external air flow on transmission loss was simulated in a subsonic wind-tunnel. By numerically evaluating the known equations for field-incidence transmission loss of single-walled panels in a computer program, a comparison of the theory with the test results was made. As a further extension to aircraft fuselage simulation, equations for the field-incidence transmission loss of a double-walled panel were derived. Flow is shown to provide a small increase in transmission loss for a flat panel. Curvature is shown to increase transmission loss for low frequencies, while also providing a sharp decrease in transmission loss at the ring frequency of the cylindrical panel. The field-incidence transmission loss of a double-walled panel was found to be approximately twice that for a single-walled panel, with the addition of dips in the transmission loss at the air gap resonances and at the critical frequency of the internal panel.

Casting the Coronal Magnetic Field Reconstructions with Magnetic Field Constraints above the Photosphere in 3D Using MHD Bifrost Model

NASA Astrophysics Data System (ADS)

Fleishman, G. D.; Anfinogentov, S.; Loukitcheva, M.; Mysh'yakov, I.; Stupishin, A.

2017-12-01

Measuring and modeling coronal magnetic field, especially above active regions (ARs), remains one of the central problems of solar physics given that the solar coronal magnetism is the key driver of all solar activity. Nowadays the coronal magnetic field is often modelled using methods of nonlinear force-free field reconstruction, whose accuracy has not yet been comprehensively assessed. Given that the coronal magnetic probing is routinely unavailable, only morphological tests have been applied to evaluate performance of the reconstruction methods and a few direct tests using available semi-analytical force-free field solution. Here we report a detailed casting of various tools used for the nonlinear force-free field reconstruction, such as disambiguation methods, photospheric field preprocessing methods, and volume reconstruction methods in a 3D domain using a 3D snapshot of the publicly available full-fledged radiative MHD model. We take advantage of the fact that from the realistic MHD model we know the magnetic field vector distribution in the entire 3D domain, which enables us to perform "voxel-by-voxel" comparison of the restored magnetic field and the true magnetic field in the 3D model volume. Our tests show that the available disambiguation methods often fail at the quiet sun areas, where the magnetic structure is dominated by small-scale magnetic elements, while they work really well at the AR photosphere and (even better) chromosphere. The preprocessing of the photospheric magnetic field, although does produce a more force-free boundary condition, also results in some effective `elevation' of the magnetic field components. The effective `elevation' height turns out to be different for the longitudinal and transverse components of the magnetic field, which results in a systematic error in absolute heights in the reconstructed magnetic data cube. The extrapolation performed starting from actual AR photospheric magnetogram (i.e., without preprocessing) are free from this systematic error, while have other metrics either comparable or only marginally worse than those estimated for extrapolations from the preprocessed magnetograms. This finding favors the use of extrapolations from the original photospheric magnetogram without preprocessing.

Flight service evaluation of composite helicopter components

NASA Technical Reports Server (NTRS)

Rich, M. J.; Lowry, D. W.

1983-01-01

This first interim report presents the technical background for including environmental effects in the design of helicopter composite structures, and test results after approximately two year field exposure of components and panels. Composite structural components were removed from Sikorsky S-76 helicopters commercially operated in the Gulf Coast region of Louisiana. Fatigue tests were conducted for a graphite/epoxy tail rotor spar and static test for a graphite/epoxy and Kevlar/epoxy stabilizer. Graphite/epoxy and Kevlar/epoxy panels are being exposed to the outdoor environment in Stratford, Connecticut and West Palm Beach, Florida. For this reporting period the two year panels were returned, moisture measurements taken, and strength tests conducted. Results are compared with initial type certificate strengths for components and with initial laboratory coupon tests for the exposed panels. Comparisons are also presented with predicted and measured moisture contents.

Flight service evaluation of composite helicopter components

NASA Technical Reports Server (NTRS)

Rich, M. J.; Lowry, D. W.

1982-01-01

This first interim report presents the technical background for including environmental effects in the design of helicopter composite structures, and test results after approximately two year field exposure of components and panels. Composite structural components were removed from Sikorsky S-76 helicopters commercially operated in the Gulf Coast region of Louisiana. Fatigue tests were conducted for a graphite/epoxy tail rotor spar and static test for a graphite/epoxy and Kevlar/epoxy stabilizer. Graphite/epoxy and Kevlar/epoxy panels are being exposed to the outdoor environment in Stratford, Connecticut and West Palm Beach, Florida. For this reporting period the two year panels were returned, moisture measurements taken, and strength tests conducted. Results are compared with initial type certificate strengths for components and with initial laboratory coupon tests for the exposed panels. Comparisons are also presented with predicted and measured moisture contents.

Comparison of Test Stand and Helicopter Oil Cooler Bearing Condition Indicators

NASA Technical Reports Server (NTRS)

Dempsey, Paula J.; Branning, Jeremy; Wade, Damiel R.; Bolander, Nathan

2010-01-01

The focus of this paper was to compare the performance of HUMS condition indicators (CI) when detecting a bearing fault in a test stand or on a helicopter. This study compared data from two sources: first, CI data collected from accelerometers installed on two UH-60 Black Hawk helicopters when oil cooler bearing faults occurred, along with data from helicopters with no bearing faults; and second, CI data that was collected from ten cooler bearings, healthy and faulted, that were removed from fielded helicopters and installed in a test stand. A method using Receiver Operating Characteristic (ROC) curves to compare CI performance was demonstrated. Results indicated the bearing energy CI responded differently for the helicopter and the test stand. Future research is required if test stand data is to be used validate condition indicator performance on a helicopter.

Field measurements and modeling of dilution in the wake of a US navy frigate.

PubMed

Katz, C N; Chadwick, D B; Rohr, J; Hyman, M; Ondercin, D

2003-08-01

A field measurement and computer modeling effort was made to assess the dilution field of pulped waste materials discharged into the wake of a US Navy frigate. Pulped paper and fluorescein dye were discharged from the frigate's pulper at known rates. The subsequent particle and dye concentration field was then measured throughout the wake by a following vessel using multiple independent measures. Minimum dilution of the pulped paper reached 3.2 x 10(5) within 1900 m behind the frigate, or about 8 min after discharge. Independent measures typically agreed within 25% of one another and within 20% of model predictions. Minimum dilution of dye reached 2.3 x 10(5) at a down-wake distance of approximately 3500 m, or roughly 15 min. Comparison to model measurements were again within 20%. The field test was not only successful at characterizing wake dilution under one set of at-sea conditions, but was successful at validating the computer model used for assessing a wide range of ships and conditions.

Summary of dipole field angle measurements on 50mm-aperture SSC Collider Dipole Magnet Protoypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marks, J.; DiMarco, J.; Kuzminski, J.

At several stages in the production of the SSC collider dipole magnets and their final installation the magnetic field angle needs to be known. A simple device using a permanent magnet which aligns itself with the magnetic field had been developed at FNAL to survey the direction of the magnetic dipole field with respect to the vertical (as determined by gravity) along the magnet axis. The determination of the dipole field angle was part of the field quality characterization of a series of thirteen full-length 50mm-aperture SSC Collider Dipole Magnet Prototypes which were built for R&D purposes at FNAL. Measurementsmore » with the first developed FAP system were performed on a regular basis through several stages of the magnet production process with the intention of fabrication quality control. Part of these included measurements performed before and after cryogenic testing: these data are summarized here. The performance of a second system with an improved probe and data acquisition system was tested on part of the DCA series as well. This paper includes a presentation of time stability, noise and angular resolution data of this second probe. Another alternative instrument to determine the dipole field angle is the ``mole`` rotating coil system developed at BNL used mainly to measure the multipole components of the magnetic field. In the case of magnet DCA320, a comparison is made between the field angle as determined by the mole and those determined by both of the FAPS.« less

Space-time mesh adaptation for solute transport in randomly heterogeneous porous media.

PubMed

Dell'Oca, Aronne; Porta, Giovanni Michele; Guadagnini, Alberto; Riva, Monica

2018-05-01

We assess the impact of an anisotropic space and time grid adaptation technique on our ability to solve numerically solute transport in heterogeneous porous media. Heterogeneity is characterized in terms of the spatial distribution of hydraulic conductivity, whose natural logarithm, Y, is treated as a second-order stationary random process. We consider nonreactive transport of dissolved chemicals to be governed by an Advection Dispersion Equation at the continuum scale. The flow field, which provides the advective component of transport, is obtained through the numerical solution of Darcy's law. A suitable recovery-based error estimator is analyzed to guide the adaptive discretization. We investigate two diverse strategies guiding the (space-time) anisotropic mesh adaptation. These are respectively grounded on the definition of the guiding error estimator through the spatial gradients of: (i) the concentration field only; (ii) both concentration and velocity components. We test the approach for two-dimensional computational scenarios with moderate and high levels of heterogeneity, the latter being expressed in terms of the variance of Y. As quantities of interest, we key our analysis towards the time evolution of section-averaged and point-wise solute breakthrough curves, second centered spatial moment of concentration, and scalar dissipation rate. As a reference against which we test our results, we consider corresponding solutions associated with uniform space-time grids whose level of refinement is established through a detailed convergence study. We find a satisfactory comparison between results for the adaptive methodologies and such reference solutions, our adaptive technique being associated with a markedly reduced computational cost. Comparison of the two adaptive strategies tested suggests that: (i) defining the error estimator relying solely on concentration fields yields some advantages in grasping the key features of solute transport taking place within low velocity regions, where diffusion-dispersion mechanisms are dominant; and (ii) embedding the velocity field in the error estimator guiding strategy yields an improved characterization of the forward fringe of solute fronts which propagate through high velocity regions. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of Pumped and Diffusion Sampling Methods to Monitor Concentrations of Perchlorate and Explosive Compounds in Ground Water, Camp Edwards, Cape Cod, Massachusetts, 2004-05

USGS Publications Warehouse

LeBlanc, Denis R.; Vroblesky, Don A.

2008-01-01

Laboratory and field tests were conducted at Camp Edwards on the Massachusetts Military Reservation on Cape Cod to examine the utility of passive diffusion sampling for long-term monitoring of concentrations of perchlorate and explosive compounds in ground water. The diffusion samplers were constructed of 1-inch-diameter rigid, porous polyethylene tubing. The results of laboratory tests in which diffusion samplers were submerged in containers filled with ground water containing perchlorate, RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), and HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) indicate that concentrations inside the diffusion samplers equilibrated with concentrations in the containers within the 19-day-long test period. Field tests of the diffusion samplers were conducted in 15 wells constructed of 2- or 2.5-inch-diameter polyvinyl chloride pipe with 10-foot-long slotted screens. Concentrations of perchlorate, RDX, and HMX in the diffusion samplers placed in the wells for 42 to 52 days were compared to concentrations in samples collected by low-flow pumped sampling from 53 days before to 109 days after retrieval of the diffusion samples. The results of the field tests indicate generally good agreement between the pumped and diffusion samples for concentrations of perchlorate, RDX, and HMX. The concentration differences indicate no systematic bias related to contaminant type or concentration levels.

Inter-laboratory Comparison of Three Earplug Fit-test Systems

PubMed Central

Byrne, David C.; Murphy, William J.; Krieg, Edward F.; Ghent, Robert M.; Michael, Kevin L.; Stefanson, Earl W.; Ahroon, William A.

2017-01-01

The National Institute for Occupational Safety and Health (NIOSH) sponsored tests of three earplug fit-test systems (NIOSH HPD Well-Fit™, Michael & Associates FitCheck, and Honeywell Safety Products VeriPRO®). Each system was compared to laboratory-based real-ear attenuation at threshold (REAT) measurements in a sound field according to ANSI/ASA S12.6-2008 at the NIOSH, Honeywell Safety Products, and Michael & Associates testing laboratories. An identical study was conducted independently at the U.S. Army Aeromedical Research Laboratory (USAARL), which provided their data for inclusion in this report. The Howard Leight Airsoft premolded earplug was tested with twenty subjects at each of the four participating laboratories. The occluded fit of the earplug was maintained during testing with a soundfield-based laboratory REAT system as well as all three headphone-based fit-test systems. The Michael & Associates lab had highest average A-weighted attenuations and smallest standard deviations. The NIOSH lab had the lowest average attenuations and the largest standard deviations. Differences in octave-band attenuations between each fit-test system and the American National Standards Institute (ANSI) sound field method were calculated (Attenfit-test - AttenANSI). A-weighted attenuations measured with FitCheck and HPD Well-Fit systems demonstrated approximately ±2 dB agreement with the ANSI sound field method, but A-weighted attenuations measured with the VeriPRO system underestimated the ANSI laboratory attenuations. For each of the fit-test systems, the average A-weighted attenuation across the four laboratories was not significantly greater than the average of the ANSI sound field method. Standard deviations for residual attenuation differences were about ±2 dB for FitCheck and HPD Well-Fit compared to ±4 dB for VeriPRO. Individual labs exhibited a range of agreement from less than a dB to as much as 9.4 dB difference with ANSI and REAT estimates. Factors such as the experience of study participants and test administrators, and the fit-test psychometric tasks are suggested as possible contributors to the observed results. PMID:27786602

Physique and Performance of Young Wheelchair Basketball Players in Relation with Classification

PubMed Central

Zancanaro, Carlo

2015-01-01

The relationships among physical characteristics, performance, and functional ability classification of younger wheelchair basketball players have been barely investigated to date. The purpose of this work was to assess anthropometry, body composition, and performance in sport-specific field tests in a national sample of Italian younger wheelchair basketball players as well as to evaluate the association of these variables with the players’ functional ability classification and game-related statistics. Several anthropometric measurements were obtained for 52 out of 91 eligible players nationwide. Performance was assessed in seven sport-specific field tests (5m sprint, 20m sprint with ball, suicide, maximal pass, pass for accuracy, spot shot and lay-ups) and game-related statistics (free-throw points scored per match, two- and three-point field-goals scored per match, and their sum). Association between variables, and predictivity was assessed by correlation and regression analysis, respectively. Players were grouped into four Classes of increasing functional ability (A-D). One-way ANOVA with Bonferroni’s correction for multiple comparisons was used to assess differences between Classes. Sitting height and functional ability Class especially correlated with performance outcomes, but wheelchair basketball experience and skinfolds did not. Game-related statistics and sport-specific field-test scores all showed significant correlation with each other. Upper arm circumference and/or maximal pass and lay-ups test scores were able to explain 42 to 59% of variance in game-related statistics (P<0.001). A clear difference in performance was only found for functional ability Class A and D. Conclusion: In younger wheelchair basketball players, sitting height positively contributes to performance. The maximal pass and lay-ups test should be carefully considered in younger wheelchair basketball training plans. Functional ability Class reflects to a limited extent the actual differences in performance. PMID:26606681

Repeatability of automated perimetry: a comparison between standard automated perimetry with stimulus size III and V, matrix, and motion perimetry.

PubMed

Wall, Michael; Woodward, Kimberly R; Doyle, Carrie K; Artes, Paul H

2009-02-01

Standard automated perimetry (SAP) shows a marked increase in variability in damaged areas of the visual field. This study was conducted to test the hypothesis that larger stimuli are associated with more uniform variability, by investigating the retest variability of four perimetry tests: standard automated perimetry size III (SAP III), with the SITA standard strategy; SAP size V (SAP V), with the full-threshold strategy; Matrix (FDT II), and Motion perimetry. One eye each of 120 patients with glaucoma was examined on the same day with these four perimetric tests and retested 1 to 8 weeks later. The decibel scales were adjusted to make the test's scales numerically similar. Retest variability was examined by establishing the distributions of retest threshold estimates, for each threshold level observed at the first test. The 5th and 95th percentiles of the retest distribution were used as point-wise limits of retest variability. Regression analyses were performed to quantify the relationship between visual field sensitivity and variability. With SAP III, the retest variability increased substantially with reducing sensitivity. Corresponding increases with SAP V, Matrix, and Motion perimetry were considerably smaller or absent. With SAP III, sensitivity explained 22% of the retest variability (r(2)), whereas corresponding data for SAP V, Matrix, and Motion perimetry were 12%, 2%, and 2%, respectively. Variability of Matrix and Motion perimetry does not increase as substantially as that of SAP III in damaged areas of the visual field. Increased sampling with the larger stimuli of these techniques is the likely explanation for this finding. These properties may make these stimuli excellent candidates for early detection of visual field progression.

On comparison of net survival curves.

PubMed

Pavlič, Klemen; Perme, Maja Pohar

2017-05-02

Relative survival analysis is a subfield of survival analysis where competing risks data are observed, but the causes of death are unknown. A first step in the analysis of such data is usually the estimation of a net survival curve, possibly followed by regression modelling. Recently, a log-rank type test for comparison of net survival curves has been introduced and the goal of this paper is to explore its properties and put this methodological advance into the context of the field. We build on the association between the log-rank test and the univariate or stratified Cox model and show the analogy in the relative survival setting. We study the properties of the methods using both the theoretical arguments as well as simulations. We provide an R function to enable practical usage of the log-rank type test. Both the log-rank type test and its model alternatives perform satisfactory under the null, even if the correlation between their p-values is rather low, implying that both approaches cannot be used simultaneously. The stratified version has a higher power in case of non-homogeneous hazards, but also carries a different interpretation. The log-rank type test and its stratified version can be interpreted in the same way as the results of an analogous semi-parametric additive regression model despite the fact that no direct theoretical link can be established between the test statistics.

Definition and measurement of rider-intrinsic physical attributes influencing all-terrain vehicle safety.

PubMed

Mattei, Tobias A; Bond, Brandon J; Hafner, John W; Morris, Martin J; Travis, Jennifer; Hannah, Greg; Webster, Jim; Lin, Julian J

2011-11-01

All-terrain vehicle (ATV) usage has grown tremendously over the years, reaching 9.5 million vehicles in use in 2007. Accompanying this growth has been a concomitant increase in rider morbidity (including traumatic brain and spine injuries) and death, especially in children. The purpose of this study was to define and measure, through field testing, those physical attributes intrinsic to riders, such as height, weight, and wingspan, which may have implications for ATV riders' safety. Three field tests (J-hook, brake, and bump) were developed and performed to allow direct measurement of the lateral, longitudinal, and vertical dynamics in 5 riders of varying heights, weights, and wingspans. Two ATVs, a utility and a sport model, were tested for further comparisons. Data were acquired using a comprehensive data acquisition system attached to the ATVs. Assignment of individual rider/ATV test safety ratings and a rider/ATV Total Safety Rating were made from the results of these field tests. The J-hook test results demonstrated that larger rider wingspans positively influence ATV rider safety and mitigate against lateral instability. From the brake test it was determined that a 10-in (25.4-cm) longitudinal displacement, such as that experienced during a sharp deceleration, for a rider of any height or weight, breached the level of defined safety. As rider weight increased, displacement decreased. The bump test provided evidence that increased rider weight also mitigates against vertical displacement. Individuals with light weights and small wingspans, such as those in the pediatric population, are under considerable risk of injury when operating an ATV due to lateral, longitudinal, and vertical operational instability.

Comparative study on the efficiency of some optical methods for artwork diagnostics

NASA Astrophysics Data System (ADS)

Schirripa Spagnolo, Giuseppe; Ambrosini, Dario; Paoletti, Domenica

2001-10-01

Scientific investigation methods are founding their place besides the stylistic-historical study methods in art research works. In particular, optical techniques, transferred from other fields or developed ad hoc, can make a strong contribution to the safeguarding and exploitation of cultural heritage. This paper describes the use of different optical techniques, such as holographic interferometry, decorrelation, shearography and ESPI, in the diagnostics of works of art. A comparison between different methods is obtained by performing tests on specially designed models, prepared using typical techniques and materials. Inside the model structure, a number of defects of known types, form and extension are inserted. The different features of each technique are outlined and a comparison with IR thermography is also carried out.

SU-F-T-472: Validation of Absolute Dose Measurements for MR-IGRT With and Without Magnetic Field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, O; Li, H; Goddu, S

Purpose: To validate absolute dose measurements for a MR-IGRT system without presence of the magnetic field. Methods: The standard method (AAPM’s TG-51) of absolute dose measurement with ionization chambers was tested with and without the presence of the magnetic field for a clinical 0.32-T Co-60 MR-IGRT system. Two ionization chambers were used - the Standard Imaging (Madison, WI) A18 (0.123 cc) and the PTW (Freiburg, Germany). A previously reported Monte Carlo simulation suggested a difference on the order of 0.5% for dose measured with and without the presence of the magnetic field, but testing this was not possible until anmore » engineering solution to allow the radiation system to be used without the nominal magnetic field was found. A previously identified effect of orientation in the magnetic field was also tested by placing the chamber either parallel or perpendicular to the field and irradiating from two opposing angles (90 and 270). Finally, the Imaging and Radiation Oncology Core provided OSLD detectors for five irradiations each with and without the field - with two heads at both 0 and 90 degrees, and one head at 90 degrees only as it doesn’t reach 0 (IEC convention). Results: For the TG-51 comparison, expected dose was obtained by decaying values measured at the time of source installation. The average measured difference was 0.4%±0.12% for A18 and 0.06%±0.15% for Farmer chamber. There was minimal (0.3%) orientation dependence without the magnetic field for the A18 chamber, while previous measurements with the magnetic field had a deviation of 3.2% with chamber perpendicular to magnetic field. Results reported by IROC for the OSLDs with and without the field had a maximum difference of 2%. Conclusion: Accurate absolute dosimetry was verified by measurement under the same conditions with and without the magnetic field for both ionization chambers and independently-verifiable OSLDs.« less

Immunization of pacific salmon: comparison of intraperitoneal injection and hyperosmotic infiltration of Vibrio anguillarum and Aeromonas salmonicida bacterins

USGS Publications Warehouse

Antipa, Ross; Amend, Donald F.

1977-01-01

Two methods of immunizing fish, intraperitoneal (i.p.) injection and hyperosmotic infiltration, were compared for control of vibriosis and furunculosis in pen-reared coho salmon (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha). Both methods provided significant protection against vibriosis under field test conditions. In coho salmon, hyperosmotic infiltration provided the best protection and fastest rise in antibody titer of seven treatments tested. In chinook salmon, hyperosmotic infiltration of Vibrio anguillarum and Aeromonas salmonicida vaccines resulted in 83.3% survival in comparison with 28.7% survival in controls. Both i.p. injection and hyperosmotic infiltration of V. anguillarum and A. salmonicida bacterins resulted in production of serum antibodies specific for each respective pathogen. Vaccination with bivalent V. anguillarum–A.salmonicida vaccines produced antibodies to both pathogens, and provided protection against vibriosis. Growth rates of vaccinated coho salmon were not significantly different from controls.

IL-4 Knock out Mice Display Anxiety-like Behavior

PubMed Central

Moon, Morgan L.; Joesting, Jennifer J.; Blevins, Neil A.; Lawson, Marcus A.; Gainey, Stephen J.; Towers, Albert E.; McNeil, Leslie K.; Freund, Gregory G.

2015-01-01

Inflammation is a recognized antecedent and coincident factor when examining the biology of anxiety. Little is known, however, about how reductions in endogenous anti-inflammatory mediators impact anxiety. Therefore, mood- cognition- and anxiety-associated/like behaviors were examined in IL-4 knock out (KO) mice and wild-type (WT) mice. In comparison to WT mice, IL-4 KO mice demonstrated decreased burrowing and increased social exploration. No differences were seen in forced swim or saccharine preference testing. IL-4 KO mice had similar performance to WT mice in the Morris water maze and during object location and novel object recognition. In the elevated zero-maze, IL-4 KO mice, in comparison to WT mice, demonstrated anxiety-like behavior. Anxiety-like behavior in IL-4 KO mice was not observed, however, during open-field testing. Taken together, these data indicate that IL-4 KO mice display state, but not trait, anxiety suggesting that reductions in endogenous anti-inflammatory bioactives can engender subtypes of anxiety. PMID:25772794

IL-4 Knock Out Mice Display Anxiety-Like Behavior.

PubMed

Moon, Morgan L; Joesting, Jennifer J; Blevins, Neil A; Lawson, Marcus A; Gainey, Stephen J; Towers, Albert E; McNeil, Leslie K; Freund, Gregory G

2015-07-01

Inflammation is a recognized antecedent and coincident factor when examining the biology of anxiety. Little is known, however, about how reductions in endogenous anti-inflammatory mediators impact anxiety. Therefore, mood- cognition- and anxiety-associated/like behaviors were examined in IL-4 knock out (KO) mice and wild-type (WT) mice. In comparison to WT mice, IL-4 KO mice demonstrated decreased burrowing and increased social exploration. No differences were seen in forced swim or saccharine preference testing. IL-4 KO mice had similar performance to WT mice in the Morris water maze and during object location and novel object recognition. In the elevated zero-maze, IL-4 KO mice, in comparison to WT mice, demonstrated anxiety-like behavior. Anxiety-like behavior in IL-4 KO mice was not observed, however, during open-field testing. Taken together, these data indicate that IL-4 KO mice display state, but not trait, anxiety suggesting that reductions in endogenous anti-inflammatory bioactives can engender subtypes of anxiety.

Development of a menu of performance tests self-administered on a portable microcomputer

NASA Technical Reports Server (NTRS)

Wilkes, Robert L.; Kuntz, Lois-Ann; Kennedy, Robert S.

1987-01-01

Eighteen cognitive, motor, and information processing performance subtests were screened for self-administration over 10 trials by 16 subjects. When altered presentation forms of the same test were collectively considered, the battery composition was reduced to 10 distinctly different measures. A fully automated microbased testing system was employed in presenting the battery of subtests. Successful self-administration of the battery provided for the field testing of the automated system and facilitated convenient data collection. Total test administration time was 47.2 minutes for each session. Results indicated that nine of the tests stabilized, but for a short battery of tests only five are recommended for use in repeated-measures research. The five recommended tests include: the Tapping series, Number Comparison, Short-term Memory, Grammatical Reasoning, and 4-Choice Reaction Time. These tests can be expected to reveal three factors: (1) cognition, (2) processing quickness, and (3) motor. All the tests stabilized in 24 minutes, or approximately two 12-minute sessions.

Ice Water Classification Using Statistical Distribution Based Conditional Random Fields in RADARSAT-2 Dual Polarization Imagery

NASA Astrophysics Data System (ADS)

Zhang, Y.; Li, F.; Zhang, S.; Hao, W.; Zhu, T.; Yuan, L.; Xiao, F.

2017-09-01

In this paper, Statistical Distribution based Conditional Random Fields (STA-CRF) algorithm is exploited for improving marginal ice-water classification. Pixel level ice concentration is presented as the comparison of methods based on CRF. Furthermore, in order to explore the effective statistical distribution model to be integrated into STA-CRF, five statistical distribution models are investigated. The STA-CRF methods are tested on 2 scenes around Prydz Bay and Adélie Depression, where contain a variety of ice types during melt season. Experimental results indicate that the proposed method can resolve sea ice edge well in Marginal Ice Zone (MIZ) and show a robust distinction of ice and water.

Value of the Cosmological Constant in Emergent Quantum Gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogan, Craig

It is suggested that the exact value of the cosmological constant could be derived from first principles, based on entanglement of the Standard Model field vacuum with emergent holographic quantum geometry. For the observed value of the cosmological constant, geometrical information is shown to agree closely with the spatial information density of the QCD vacuum, estimated in a free-field approximation. The comparison is motivated by a model of exotic rotational fluctuations in the inertial frame that can be precisely tested in laboratory experiments. Cosmic acceleration in this model is always positive, but fluctuates with characteristic coherence lengthmore » $$\\approx 100$$km and bandwidth $$\\approx 3000$$ Hz.« less

Field and laboratory comparison of the sensitivity and reliability of cocaine detection on currency using chemical sensors, humans, K-9s, and SPME/GC/MS/MS analysis

NASA Astrophysics Data System (ADS)

Furton, Kenneth G.; Hsu, Ya-Li; Luo, Tien-Ying; Norelus, Arnold; Rose, Stefan

1999-02-01

Reports that money in general circulation is contaminated with cocaine have resulted in contaminated money theories purporting that any person carrying currency could potentially initiate a drug dog alert. Field tests on dozens of different drug detector dogs with widely varying breeds, ages and training regimes show a consistent threshold level of 1 - 10 (mu) g of methyl benzoate spiked along with cocaine on U.S. currency or 0.1 - 1 ng/sec methyl benzoate diffusion required to initiate an alert. No other substance studied to data has initiated consistent responses by the drug dogs studied.

Low-cost extrapolation method for maximal LTE radio base station exposure estimation: test and validation.

PubMed

Verloock, Leen; Joseph, Wout; Gati, Azeddine; Varsier, Nadège; Flach, Björn; Wiart, Joe; Martens, Luc

2013-06-01

An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on downlink band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2×2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders.

A three-dimensional turbulent separated flow and related mesurements

NASA Technical Reports Server (NTRS)

Pierce, F. J.

1985-01-01

The applicability of and the limits on the applicability of 11 near wall similarity laws characterizing three-dimensional turbulent boundary layer flows were determined. A direct force sensing local wall shear stress meter was used in both pressure-driven and shear-driven three-dimensional turbulent boundary layers, together with extensive mean velocity field and wall pressure field data. This resulted in a relatively large number of graphical comparisons of the predictive ability of 10 of these 11 similarity models relative to measured data over a wide range of flow conditions. Documentation of a complex, separated three-dimensional turbulent flow as a standard test case for evaluating the predictive ability of numerical codes solving such flows is presented.

A Novel Wireless Wearable Volatile Organic Compound (VOC) Monitoring Device with Disposable Sensors.

PubMed

Deng, Yue; Chen, Cheng; Xian, Xiaojun; Tsow, Francis; Verma, Gaurav; McConnell, Rob; Fruin, Scott; Tao, Nongjian; Forzani, Erica S

2016-12-03

A novel portable wireless volatile organic compound (VOC) monitoring device with disposable sensors is presented. The device is miniaturized, light, easy-to-use, and cost-effective. Different field tests have been carried out to identify the operational, analytical, and functional performance of the device and its sensors. The device was compared to a commercial photo-ionization detector, gas chromatography-mass spectrometry, and carbon monoxide detector. In addition, environmental operational conditions, such as barometric change, temperature change and wind conditions were also tested to evaluate the device performance. The multiple comparisons and tests indicate that the proposed VOC device is adequate to characterize personal exposure in many real-world scenarios and is applicable for personal daily use.

A Novel Wireless Wearable Volatile Organic Compound (VOC) Monitoring Device with Disposable Sensors

PubMed Central

Deng, Yue; Chen, Cheng; Xian, Xiaojun; Tsow, Francis; Verma, Gaurav; McConnell, Rob; Fruin, Scott; Tao, Nongjian; Forzani, Erica S.

2016-01-01

A novel portable wireless volatile organic compound (VOC) monitoring device with disposable sensors is presented. The device is miniaturized, light, easy-to-use, and cost-effective. Different field tests have been carried out to identify the operational, analytical, and functional performance of the device and its sensors. The device was compared to a commercial photo-ionization detector, gas chromatography-mass spectrometry, and carbon monoxide detector. In addition, environmental operational conditions, such as barometric change, temperature change and wind conditions were also tested to evaluate the device performance. The multiple comparisons and tests indicate that the proposed VOC device is adequate to characterize personal exposure in many real-world scenarios and is applicable for personal daily use. PMID:27918484

Prolonged 500 C Operation of 100+ Transistor Silicon Carbide Integrated Circuits

NASA Technical Reports Server (NTRS)

Spry, David J.; Neudeck, Philip G.; Lukco, Dorothy; Chen, Liangyu; Krasowski, Michael J.; Prokop, Norman F.; Chang, Carl W.; Beheim, Glenn M.

2017-01-01

This report describes more than 5000 hours of successful 500 C operation of semiconductor integrated circuits (ICs) with more than 100 transistors. Multiple packaged chips with two different 4H-SiC junction field effect transistor (JFET) technology demonstrator circuits have surpassed thousands of hours of oven-testing at 500 C. After 100 hours of 500 C burn-in, the circuits (except for 2 failures) exhibit less than 10% change in output characteristics for the remainder of 500 C testing. We also describe the observation of important differences in IC materials durability when subjected to the first nine constituents of Venus-surface atmosphere at 9.4 MPa and 460 C in comparison to what is observed for Earth-atmosphere oven testing at 500 C.

Prolonged 500 C Operation of 100+ Transistor Silicon Carbide Integrated Circuits

NASA Technical Reports Server (NTRS)

Spry, David J.; Neudeck, Philip G.; Lukco, Dorothy; Chen, Liangyu; Krasowski, Michael J.; Prokop, Norman F.; Chang, Carl W.; Beheim, Glenn M.

2017-01-01

This report describes more than 5000 hours of successful 500 C operation of semiconductor integrated circuits (ICs) with more than 100 transistors. Multiple packaged chips with two different 4H-SiC junction field effect transistor (JFET) technology demonstrator circuits have surpassed thousands of hours of oven-testing at 500 C. After 100 hours of 500 C burn-in, the circuits (except for 2 failures) exhibit less than 10 change in output characteristics for the remainder of 500C testing. We also describe the observation of important differences in IC materials durability when subjected to the first nine constituents of Venus-surface atmosphere at 9.4 MPa and 460C in comparison to what is observed for Earth-atmosphere oven testing at 500 C.

Automatic Docking System Sensor Design, Test, and Mission Performance

NASA Technical Reports Server (NTRS)

Jackson, John L.; Howard, Richard T.; Cole, Helen J.

1998-01-01

The Video Guidance Sensor is a key element of an automatic rendezvous and docking program administered by NASA that was flown on STS-87 in November of 1997. The system used laser illumination of a passive target in the field of view of an on-board camera and processed the video image to determine the relative position and attitude between the target and the sensor. Comparisons of mission results with theoretical models and laboratory measurements will be discussed.

Summary of gas bearing applications in the field of space electric power systems

NASA Technical Reports Server (NTRS)

Dunn, J. H.; Ream, L. W.

1972-01-01

The testing and evaluation of different bearing systems to be used in the turbine-alternator-compressor of a closed Brayton cycle electric power system are described. A specification of each bearing is presented along with the results of the evaluation and a comparison of the merits and limitations of each bearing. The contribution of improved bearings to the power supply reliability, potential life, and ability to accept shock and vibration is examined.

A Compatibility Assessment and Comparison of the Flame Resistant Chemical-Biological (CB) Overgarment with the Standard ’A’ CB Overgarment.

DTIC Science & Technology

1982-01-01

Overgarment-Dynamics .............. .19 TABLES 1. Basic Anthropometry .......... ...................... 3 2. Flame Resistant CB Overgarment Test...participants (TPs) during this evaluation. Basic anthropometry of these subjects is given in Table I. TABLE 1 Basic Anthropometry Mean SD Maximum...5 S H L XL 39 H L XL XXL 43 L XL XXL XXL The areas considered were ease of doffing and donning, compatibility with prescribed clothing and field

Utilization requirements. A southern California Gas Company project SAGE report: Utilization requirements

NASA Technical Reports Server (NTRS)

Barbieri, R. H.; Schoen, R.; Hirshberg, A. S.

1978-01-01

Utilization requirements are given and comparisons made of two phase III SAGE (solar assisted gas energy) installations in California: (1) a retrofit installation in an existing apartment building in El Toro, and (2) an installation in a new apartment building in Upland. Such testing in the field revealed the requirements to be met if SAGE-type installations are to become commercially practical on a widespread basis in electric and gas energy usage.

Orbiter BLT Flight Experiment Wind Tunnel Simulations: Nearfield Flowfield Imaging and Surface Thermography

NASA Technical Reports Server (NTRS)

Danehy, Paul M.; Ivey, Christoper B.; Barthel, Brett F.; Inman, Jennifer A.; Jones, Stephen B.; Watkins, Anthony N.; Goodman, Kyle Z.; McCrea, Andrew C.; Leighty, Bradley D.; Lipford, William K.;

Application of a single-fluid model for the steam condensing flow prediction

NASA Astrophysics Data System (ADS)

Smołka, K.; Dykas, S.; Majkut, M.; Strozik, M.

2016-10-01

One of the results of many years of research conducted in the Institute of Power Engineering and Turbomachinery of the Silesian University of Technology are computational algorithms for modelling steam flows with a non-equilibrium condensation process. In parallel with theoretical and numerical research, works were also started on experimental testing of the steam condensing flow. This paper presents a comparison of calculations of a flow field modelled by means of a single-fluid model using both an in-house CFD code and the commercial Ansys CFX v16.2 software package. The calculation results are compared to inhouse experimental testing.

Assessment of simulation fidelity using measurements of piloting technique in flight. II

NASA Technical Reports Server (NTRS)

Ferguson, S. W.; Clement, W. F.; Hoh, R. H.; Cleveland, W. B.

1985-01-01

Two components of the Vertical Motion Simulator (presently being used to assess the fidelity of UH-60A simulation) are evaluated: (1) the dash/quickstop Nap-of-the-earth (NOE) piloting task, and (2) the bop-up task. Data from these two flight test experiments are presented which provide information on the effect of reduced visual field of view, variation in scene content and texture, and the affect of pure time delay in the closed-loop pilot response. In comparison with task performance results obtained in flight tests, the results from the simulation indicate that the pilot's NOE task performance in the simulator is significantly degraded.

Direct Comparison of the Histidine-rich Protein-2 Enzyme-linked Immunosorbent Assay (HRP-2 ELISA) and Malaria SYBR Green I Fluorescence (MSF) Drug Sensitivity Tests in Plasmodium falciparum Reference Clones and Fresh ex vivo Field Isolates from Cambodia

DTIC Science & Technology

2013-07-12

assessment of antimalarial activity in vitro by a semiautomated microdilution technique. Antimicrob Agents Chemother 1979, 16:710–718. 3. Noedl H, Attlmayr B...40:685–691. 32. Hawley SR, Bray PG, Mungthin M, Atkinson JD, O’Neill PM, Ward SA: Relationship between antimalarial drug activity , accumulation, and...success rate when testing DHA, AS, MQ, QN, CQ, and PPQ activities . A “successful” IC50 assay result for each P. falciparum clinical isolate was defined as

Tectonic tests of proposed polar wander paths for Mars and the moon

NASA Technical Reports Server (NTRS)

Grimm, R. E.; Solomon, S. C.

1986-01-01

A comparison of the lithospheric stress field predicted for rapid global reorientations against observed tectonic features is used to test the polar wander paths proposed for Mars by Schultz and Lutz-Garihan (1981). A calculation of the reorientation stresses leads to the suggestion that the formation of normal faults or graben in broad regions around the former rotation poles should be the minimum tectonic signature of a reorientation that generates lithospheric stresses in excess of the extensional strength of near-surface material. It is concluded that polar wander of the magnitude and timing envisioned by Schultz and Lutz-Garihan did not occur.

Acoustic temperature measurement in a rocket noise field.

PubMed

Giraud, Jarom H; Gee, Kent L; Ellsworth, John E

2010-05-01

A 1 μm diameter platinum wire resistance thermometer has been used to measure temperature fluctuations generated during a static GEM-60 rocket motor test. Exact and small-signal relationships between acoustic pressure and acoustic temperature are derived in order to compare the temperature probe output with that of a 3.18 mm diameter condenser microphone. After preliminary plane wave tests yielded good agreement between the transducers within the temperature probe's ∼2 kHz bandwidth, comparison between the temperature probe and microphone data during the motor firing show that the ±∼3 K acoustic temperature fluctuations are a significant contributor to the total temperature variations.

Male-produced pheromone of Spathius agrili, a parasitoid introduced for the biological control of the invasive emerald ash borer, Agrilus planipennis.

PubMed

Cossé, Allard A; Petroski, Richard J; Zilkowski, Bruce W; Vermillion, Karl; Lelito, Jonathan P; Cooperband, Miriam F; Gould, Juli R

2012-04-01

The braconid wasp, Spathius agrili, has been released in the U.S. as a biocontrol agent for the invasive emerald ash borer (Coleoptera: Buprestidae: Agrilus planipennis), a destructive pest of ash trees (Fraxinus spp.). We identified and synthesized seven male-specific volatile compounds. Three of these, dodecanal, (4R,11E)-tetradecen-4-olide, and (Z)-10-heptadecen-2-one, were the key behaviorally active components in flight tunnel bioassays. Male specificity was demonstrated by gas chromatographic comparison of male and female volatile emissions and whole body extracts. Identifications were aided by coupled gas chromatographic-mass spectrometric (GC-MS) analysis, microchemical reactions, NMR, chiral GC analysis, and GC and MS comparison with authentic standards. Both the racemic and chiral forms of the γ-lactone, as well as both E- and Z-isomers were synthesized. Flight tunnel behavioral tests showed positive male and female S. agrili responses to both natural pheromone and synthetic blends, with upwind flight and landing on the source. Large field-cage tests, using yellow sticky traps baited with pheromone, captured approximately 50% of the released male and female wasps in 24-h periods. The use of pheromone-baited traps in the field could simplify the current detection method for determining parasitoid establishment (i.e., laboriously felling and peeling ash trees for recovery of S. agrili from infested EAB larvae).

Field demonstration of on-site analytical methods for TNT and RDX in ground water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig, H.; Ferguson, G.; Markos, A.

1996-12-31

A field demonstration was conducted to assess the performance of eight commercially-available and emerging colorimetric, immunoassay, and biosensor on-site analytical methods for explosives 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in ground water and leachate at the Umatilla Army Depot Activity, Hermiston, Oregon and US Naval Submarine Base, Bangor, Washington, Superfund sites. Ground water samples were analyzed by each of the on-site methods and results compared to laboratory analysis using high performance liquid chromatography (HPLC) with EPA SW-846 Method 8330. The commercial methods evaluated include the EnSys, Inc., TNT and RDX colorimetric test kits (EPA SW-846 Methods 8515 and 8510) with amore » solid phase extraction (SPE) step, the DTECH/EM Science TNT and RDX immunoassay test kits (EPA SW-846 Methods 4050 and 4051), and the Ohmicron TNT immunoassay test kit. The emerging methods tested include the antibody-based Naval Research Laboratory (NRL) Continuous Flow Immunosensor (CFI) for TNT and RDX, and the Fiber Optic Biosensor (FOB) for TNT. Accuracy of the on-site methods were evaluated using linear regression analysis and relative percent difference (RPD) comparison criteria. Over the range of conditions tested, the colorimetric methods for TNT and RDX showed the highest accuracy of the emerging methods for TNT and RDX. The colorimetric method was selected for routine ground water monitoring at the Umatilla site, and further field testing on the NRL CFI and FOB biosensors will continue at both Superfund sites.« less

Aircraft turbofan noise

NASA Astrophysics Data System (ADS)

Groeneweg, J. F.; Rice, E. J.

1987-01-01

Turbofan noise generation and suppression in aircraft engines are reviewed. The chain of physical processes which connect unsteady flow interactions with fan blades to far field noise is addressed. Mechanism identification and description, duct propagation, radiation, and acoustic suppression are discussed. The experimental techniques of fan inflow static tests are discussed. Rotor blade surface pressure and wake velocity measurements aid in the determination of the types and strengths of the generation mechanisms. Approaches to predicting or measuring acoustic mode content, optimizing treatment impedance to maximize attenuation, translating impedance into porous wall structure, and interpreting far field directivity patterns are illustrated by comparisons of analytical and experimental results. The interdependence of source and acoustic treatment design to minimize far field noise is emphasized. Areas requiring further research are discussed, and the relevance of aircraft turbofan results to quieting other turbomachinery installation is addressed.

Aircraft turbofan noise

NASA Astrophysics Data System (ADS)

Groeneweg, J. F.; Rice, E. J.

1983-03-01

Turbofan noise generation and suppression in aircraft engines are reviewed. The chain of physical processes which connect unsteady flow interactions with fan blades to far field noise is addressed. Mechanism identification and description, duct propagation, radiation and acoustic suppression are discussed. The experimental technique of fan inflow static tests are discussed. Rotor blade surface pressure and wake velocity measurements aid in the determination of the types and strengths of the generation mechanisms. Approaches to predicting or measuring acoustic mode content, optimizing treatment impedance to maximize attenuation, translating impedance into porous wall structure and interpreting far field directivity patterns are illustrated by comparisons of analytical and experimental results. The interdependence of source and acoustic treatment design to minimize far field noise is emphasized. Area requiring further research are discussed and the relevance of aircraft turbofan results to quieting other turbomachinery installations is addressed.

Aircraft turbofan noise

NASA Technical Reports Server (NTRS)

Groeneweg, J. F.; Rice, E. J.

1983-01-01

Turbofan noise generation and suppression in aircraft engines are reviewed. The chain of physical processes which connect unsteady flow interactions with fan blades to far field noise is addressed. Mechanism identification and description, duct propagation, radiation and acoustic suppression are discussed. The experimental technique of fan inflow static tests are discussed. Rotor blade surface pressure and wake velocity measurements aid in the determination of the types and strengths of the generation mechanisms. Approaches to predicting or measuring acoustic mode content, optimizing treatment impedance to maximize attenuation, translating impedance into porous wall structure and interpreting far field directivity patterns are illustrated by comparisons of analytical and experimental results. The interdependence of source and acoustic treatment design to minimize far field noise is emphasized. Area requiring further research are discussed and the relevance of aircraft turbofan results to quieting other turbomachinery installations is addressed.

A rapid boundary integral equation technique for protein electrostatics

NASA Astrophysics Data System (ADS)

Grandison, Scott; Penfold, Robert; Vanden-Broeck, Jean-Marc

2007-06-01

A new boundary integral formulation is proposed for the solution of electrostatic field problems involving piecewise uniform dielectric continua. Direct Coulomb contributions to the total potential are treated exactly and Green's theorem is applied only to the residual reaction field generated by surface polarisation charge induced at dielectric boundaries. The implementation shows significantly improved numerical stability over alternative schemes involving the total field or its surface normal derivatives. Although strictly respecting the electrostatic boundary conditions, the partitioned scheme does introduce a jump artefact at the interface. Comparison against analytic results in canonical geometries, however, demonstrates that simple interpolation near the boundary is a cheap and effective way to circumvent this characteristic in typical applications. The new scheme is tested in a naive model to successfully predict the ground state orientation of biomolecular aggregates comprising the soybean storage protein, glycinin.

Simulation of the Flow Field Associated with a Rocket Thruster Having an Attached Panel

NASA Technical Reports Server (NTRS)

Davoudzadeh, Farhad; Liu, Nan-Suey

2003-01-01

Two-dimensional inviscid and viscous numerical simulations are performed to predict the flow field induced by a H2-O2 rocket thruster and to provide insight into the heat load on the articles placed in the hot gas exhaust of the thruster under a variety of operating conditions, using the National Combustion Code (NCC). The simulations have captured physical details of the flow field, such as the plume formation and expansion, formation of the shock waves and their effects on the temperature and pressure distributions on the walls of the apparatus and the flat panel. Comparison between the computed results for 2-D and adiabatic walls and the related experimental measurements for 3-D and cooled walls shows that the results of the simulations are consistent with those obtained from the related rig tests.

Familiarisation and Reliability of Sprint Test Indices During Laboratory and Field Assessment

PubMed Central

Hopker, James G.; Coleman, Damian A.; Wiles, Jonathan D.; Galbraith, Andrew

2009-01-01

The aim of the study was to assess the reliability of sprint performance in both field and laboratory conditions. Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg) and seventeen female team sport players (mean ± s: 21 ± 4 years, 1.68 ± 0. 07 m, 62.7 ± 4.7 kg) performed a maximal 20-metre sprint running test on eight separate occasions. Four trials were conducted on a non-motorised treadmill in the laboratory; the other four were conducted outdoors on a hard-court training surface with time recorded by single-beam photocells. Trials were conducted in random order with no familiarisation prior to testing. There was a significant difference between times recorded during outdoor field trials (OFT) and indoor laboratory trials (ILT) using a non-motorised treadmill (3.47 ± 0.53 vs. 6.06 ±1.17s; p < 0.001). The coefficient of variation (CV) for time was 2.55-4.22% for OFT and 5.1-7.2% for ILT. During ILT peak force (420.9 ± 87.7N), mean force (147.2 ± 24.7N), peak power (1376.8 ± 451.9W) and mean power (514.8 ± 164.4W), and were measured. The CV for all ILT variables was highest during trial 1-2 comparison. The CV (95% confidence interval) for the trial 3-4 comparison yielded: 9.4% (7.7-12. 1%), 7.9% (6.4-10.2%), 10.1% (8.2-13.1%) and 6.2% (5.1-8.0%) for PF, MF, PP and MP and respectively. The results indicate that reliable data can be derived for single maximal sprint measures, using fixed distance protocols. However, significant differences in time/speed over 20-m exist between field and laboratory conditions. This is primarily due to the frictional resistance in the non- motorised treadmill. Measures of force and power during ILT require at least 3 familiarisations to reduce variability in test scores. Key points Reliable data can be derived from single maximal sprint measures in both indoor and outdoor environments using fixed distance protocols. There may be significant time differences to complete fixed distance trials between the two environments. Measures of mean force, peak force and peak power during indoor trials may require multiple trials to reduce variability in test scores. PMID:24149593

Multilayer Markov Random Field models for change detection in optical remote sensing images

NASA Astrophysics Data System (ADS)

Benedek, Csaba; Shadaydeh, Maha; Kato, Zoltan; Szirányi, Tamás; Zerubia, Josiane

2015-09-01

In this paper, we give a comparative study on three Multilayer Markov Random Field (MRF) based solutions proposed for change detection in optical remote sensing images, called Multicue MRF, Conditional Mixed Markov model, and Fusion MRF. Our purposes are twofold. On one hand, we highlight the significance of the focused model family and we set them against various state-of-the-art approaches through a thematic analysis and quantitative tests. We discuss the advantages and drawbacks of class comparison vs. direct approaches, usage of training data, various targeted application fields and different ways of Ground Truth generation, meantime informing the Reader in which roles the Multilayer MRFs can be efficiently applied. On the other hand we also emphasize the differences between the three focused models at various levels, considering the model structures, feature extraction, layer interpretation, change concept definition, parameter tuning and performance. We provide qualitative and quantitative comparison results using principally a publicly available change detection database which contains aerial image pairs and Ground Truth change masks. We conclude that the discussed models are competitive against alternative state-of-the-art solutions, if one uses them as pre-processing filters in multitemporal optical image analysis. In addition, they cover together a large range of applications, considering the different usage options of the three approaches.

Active Time-Domain Reflectometry for Unattended Safeguards Systems FY15 Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tedeschi, Jonathan R.; Smith, Leon E.; Moore, David E.

2015-09-01

The International Atomic Energy Agency (IAEA) continues to expand its use of unattended measurement systems. An increasing number of systems and an expanding family of instruments create challenges in terms of deployment efficiency and the implementation of data authentication measures. In collaboration with the IAEA, tamper-indicating measures to address data-transmission authentication challenges with unattended safeguards systems are under investigation. Pacific Northwest National Laboratory (PNNL) is studying the viability of active time-domain reflectometry (TDR) along two parallel but interconnected paths: (1) swept-frequency TDR as the highly flexible, laboratory gold standard to which field-deployable options can be compared, and (2) a low-costmore » commercially available spread-spectrum TDR technology as one option for field implementation. This report describes PNNL’s FY15 progress in the viability study including: an overview of the TDR methods under investigation; description of the testing configurations and mock tampering scenarios; results from a preliminary sensitivity comparison of the two TDR methods; demonstration of a quantitative metric for estimating field performance that acknowledges the need for high detection probability while minimizing false alarms. FY15 progress reported here sets the stage for a rigorous comparison of the candidate TDR methods, over a range of deployment scenarios and perturbing effects typical of IAEA unattended monitoring systems.« less

Benchmarking all-atom simulations using hydrogen exchange

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skinner, John J.; Yu, Wookyung; Gichana, Elizabeth K.

We are now able to fold small proteins reversibly to their native structures [Lindorff-Larsen K, Piana S, Dror RO, Shaw DE (2011) Science 334(6055):517–520] using long-time molecular dynamics (MD) simulations. Our results indicate that modern force fields can reproduce the energy surface near the native structure. In this paper, to test how well the force fields recapitulate the other regions of the energy surface, MD trajectories for a variant of protein G are compared with data from site-resolved hydrogen exchange (HX) and other biophysical measurements. Because HX monitors the breaking of individual H-bonds, this experimental technique identifies the stability andmore » H-bond content of excited states, thus enabling quantitative comparison with the simulations. Contrary to experimental findings of a cooperative, all-or-none unfolding process, the simulated denatured state ensemble, on average, is highly collapsed with some transient or persistent native 2° structure. The MD trajectories of this protein G variant and other small proteins exhibit excessive intramolecular H-bonding even for the most expanded conformations, suggesting that the force fields require improvements in describing H-bonding and backbone hydration. Finally and moreover, these comparisons provide a general protocol for validating the ability of simulations to accurately capture rare structural fluctuations.« less

Benchmarking all-atom simulations using hydrogen exchange

DOE PAGES

Skinner, John J.; Yu, Wookyung; Gichana, Elizabeth K.; ...

2014-10-27

We are now able to fold small proteins reversibly to their native structures [Lindorff-Larsen K, Piana S, Dror RO, Shaw DE (2011) Science 334(6055):517–520] using long-time molecular dynamics (MD) simulations. Our results indicate that modern force fields can reproduce the energy surface near the native structure. In this paper, to test how well the force fields recapitulate the other regions of the energy surface, MD trajectories for a variant of protein G are compared with data from site-resolved hydrogen exchange (HX) and other biophysical measurements. Because HX monitors the breaking of individual H-bonds, this experimental technique identifies the stability andmore » H-bond content of excited states, thus enabling quantitative comparison with the simulations. Contrary to experimental findings of a cooperative, all-or-none unfolding process, the simulated denatured state ensemble, on average, is highly collapsed with some transient or persistent native 2° structure. The MD trajectories of this protein G variant and other small proteins exhibit excessive intramolecular H-bonding even for the most expanded conformations, suggesting that the force fields require improvements in describing H-bonding and backbone hydration. Finally and moreover, these comparisons provide a general protocol for validating the ability of simulations to accurately capture rare structural fluctuations.« less

Geologic Interpretation of Data Sets Collected by Planetary Analog Geology Traverses and by Standard Geologic Field Mapping. Part 1; A Comparison Study

NASA Technical Reports Server (NTRS)

Eppler, Dean B.; Bleacher, Jacob F.; Evans, Cynthia A.; Feng, Wanda; Gruener, John; Hurwitz, Debra M.; Skinner, J. A., Jr.; Whitson, Peggy; Janoiko, Barbara

2013-01-01

Geologic maps integrate the distributions, contacts, and compositions of rock and sediment bodies as a means to interpret local to regional formative histories. Applying terrestrial mapping techniques to other planets is challenging because data is collected primarily by orbiting instruments, with infrequent, spatiallylimited in situ human and robotic exploration. Although geologic maps developed using remote data sets and limited "Apollo-style" field access likely contain inaccuracies, the magnitude, type, and occurrence of these are only marginally understood. This project evaluates the interpretative and cartographic accuracy of both field- and remote-based mapping approaches by comparing two 1:24,000 scale geologic maps of the San Francisco Volcanic Field (SFVF), north-central Arizona. The first map is based on traditional field mapping techniques, while the second is based on remote data sets, augmented with limited field observations collected during NASA Desert Research & Technology Studies (RATS) 2010 exercises. The RATS mission used Apollo-style methods not only for pre-mission traverse planning but also to conduct geologic sampling as part of science operation tests. Cross-comparison demonstrates that the Apollo-style map identifies many of the same rock units and determines a similar broad history as the field-based map. However, field mapping techniques allow markedly improved discrimination of map units, particularly unconsolidated surficial deposits, and recognize a more complex eruptive history than was possible using Apollo-style data. Further, the distribution of unconsolidated surface units was more obvious in the remote sensing data to the field team after conducting the fieldwork. The study raises questions about the most effective approach to balancing mission costs with the rate of knowledge capture, suggesting that there is an inflection point in the "knowledge capture curve" beyond which additional resource investment yields progressively smaller gains in geologic knowledge.

Implementation and validation of a wake model for vortex-surface interactions in low speed forward flight

NASA Technical Reports Server (NTRS)

Komerath, Narayanan M.; Schreiber, Olivier A.

1987-01-01

The wake model was implemented using a VAX 750 and a Microvax II workstation. Online graphics capability using a DISSPLA graphics package. The rotor model used by Beddoes was significantly extended to include azimuthal variations due to forward flight and a simplified scheme for locating critical points where vortex elements are placed. A test case was obtained for validation of the predictions of induced velocity. Comparison of the results indicates that the code requires some more features before satisfactory predictions can be made over the whole rotor disk. Specifically, shed vorticity due to the azimuthal variation of blade loading must be incorporated into the model. Interactions between vortices shed from the four blades of the model rotor must be included. The Scully code for calculating the velocity field is being modified in parallel with these efforts to enable comparison with experimental data. To date, some comparisons with flow visualization data obtained at Georgia Tech were performed and show good agreement for the isolated rotor case. Comparison of time-resolved velocity data obtained at Georgia Tech also shows good agreement. Modifications are being implemented to enable generation of time-averaged results for comparison with NASA data.

A Comparison Between The NORCAT Rover Test Results and the ISRU Excavation System Model Predictions Results

NASA Technical Reports Server (NTRS)

Gallo, Christopher A.; Agui, Juan H.; Creager, Colin M.; Oravec, Heather A.

2012-01-01

An Excavation System Model has been written to simulate the collection and transportation of regolith on the moon. The calculations in this model include an estimation of the forces on the digging tool as a result of excavation into the regolith. Verification testing has been performed and the forces recorded from this testing were compared to the calculated theoretical data. The Northern Centre for Advanced Technology Inc. rovers were tested at the NASA Glenn Research Center Simulated Lunar Operations facility. This testing was in support of the In-Situ Resource Utilization program Innovative Partnership Program. Testing occurred in soils developed at the Glenn Research Center which are a mixture of different types of sands and whose soil properties have been well characterized. This testing is part of an ongoing correlation of actual field test data to the blade forces calculated by the Excavation System Model. The results from this series of tests compared reasonably with the predicted values from the code.

Development of Scatterometer-Derived Surface Pressures

NASA Astrophysics Data System (ADS)

Hilburn, K. A.; Bourassa, M. A.; O'Brien, J. J.

2001-12-01

SeaWinds scatterometer-derived wind fields can be used to estimate surface pressure fields. The method to be used has been developed and tested with Seasat-A and NSCAT wind measurements. The method involves blending two dynamically consistent values of vorticity. Geostrophic relative vorticity is calculated from an initial guess surface pressure field (AVN analysis in this case). Relative vorticity is calculated from SeaWinds winds, adjusted to a geostrophic value, and then blended with the initial guess. An objective method applied minimizes the differences between the initial guess field and scatterometer field, subject to regularization. The long-term goal of this project is to derive research-quality pressure fields from the SeaWinds winds for the Southern Ocean from the Antarctic ice sheet to 30 deg S. The intermediate goal of this report involves generation of pressure fields over the northern hemisphere for testing purposes. Specifically, two issues need to be addressed. First, the most appropriate initial guess field will be determined: the pure AVN analysis or the previously assimilated pressure field. The independent comparison data to be used in answering this question will involve data near land, ship data, and ice data that were not included in the AVN analysis. Second, the smallest number of pressure observations required to anchor the assimilated field will be determined. This study will use Neumann (derivative) boundary conditions on the region of interest. Such boundary conditions only determine the solution to within a constant that must be determined by a number of anchoring points. The smallness of the number of anchoring points will demonstrate the viability of the general use of the scatterometer as a barometer over the oceans.

[Relationship between visual field index and visual field morphological stages of glaucoma and their diagnostic value].

PubMed

Hou, X R; Qin, J Y; Ren, Z Q

2017-02-11

Objective: To investigate the rationality of visual field morphological stages of glaucoma, its relationship with visual field index and their diagnostic value. Methods: Retrospective series case study. Two hundred and seventy-four glaucoma patients and 100 normal control received visual field examination by Humphrey perimeter using standard automatic perimetry (SAP) program from March 2014 to September 2014. Glaucoma patients were graded into four stages according to characteristic morphological damage of visual field, distribution of mean defect (MD) and visual field index (VFI) of each stage were plotted and receiver operation characteristic curve (ROC) was used to explore its correlation with MD and VFI. The diagnostic value of MD and VFI was also compared. For the comparison of general data of subjects, categorical variables were compared using χ(2) test, numerical variables were compared using F test. MD and VFI were compared using ANOVA among stages according to visual field, followed by multiple comparisons using LSD method. The correlation between MD and VFI and different stages according to visual field defined their diagnostic value, and compared using area under the curve (AUC) of ROC. Results: No characteristic visual field damage was found in normal control group, and MD and VFI was (-0.06±1.24) dB and (99.15±0.76)%, respectively. Glaucomatous visual field damage was graded into early, medium, late and end stage according to morphological characteristic. MD for each stage were (-2.83±2.00) dB, (-9.70±3.68) dB, (-18.46±2.90) dB, and (-27.96±2.76) dB, respectively. VFI for each stage were (93.84±3.61)%, (75.16±10.85)%, (49.36±11.26)% and (17.65±10.59)%, respectively. MD and VFI of each stage of glaucomatous group and normal control group were all significantly different ( F= 1 165.53 and P <0.01 for MD; F= 1 028.04 and P <0.01 for VFI). AUC of ROC was A(MD)=0.91 and Se(MD)=0.01 (95% confident interval was 0.89-0.94) for MD, and A(VFI)=0.97, Se(VFI)=0.01 (95% confident interval was 0.94-0.10) for VFI. So, AUC(VFI)>AUC(MD) ( P< 0.05). Conclusions: It is feasible and rational of glaucomatous visual field damage to be graded into early, medium, late and end stage using Humphrey perimeter. Distribution of MD and VFI for each stage was relatively concentrative. Both MD and VFI were useful for grading glaucomatous visual field damage with preference for VFI. (Chin J Ophthalmol, 2017, 53: 92-97) .

AVHRR-Based Polar Pathfinder Products: Evaluation, Enhancement, and Transition to MODIS

NASA Technical Reports Server (NTRS)

Fowler, Charles; Maslanik, James; Stone, Robert; Stroeve, Julienne; Emery, William

2001-01-01

The AVHRR-Based Polar Pathfinder (APP) products include calibrated AVHRR channel data, surface temperatures, albedo, satellite scan and solar geometries, and a cloud mask composited into twice- per-day images, and daily averaged fields of sea ice motion, for regions poleward of 50 deg. latitude. Our goals under this grant, in general, are four-fold: 1. To quantify the APP accuracy and sources of error by comparing Pathfinder products with field measurements. 2. To determine the consistency of mean fields and trends in comparison with longer time series of available station data and forecast model output. 3. To investigate the consistency of the products between the different AVHRR instruments over the 1982-present period of the NOAA program. 4. To compare an annual cycle of the AVHRR Pathfinder products with MODIS to establish a baseline for extending Pathfinder-type products into the new ESE period. Year One tasks include intercomparisons of the Pathfinder products with field measurements, testing of algorithm assumptions, collection of field data, and further validation and possible improvement of the multi-sensor ice motion fields. Achievements for these tasks are summarized below.

Normative data for the Functional Movement Screen in male Gaelic field sports.

PubMed

Fox, Domhnaill; O'Malley, Edwenia; Blake, Catherine

2014-08-01

To determine normative values for the Functional Movement Screen (FMS) in Elite and Sub-Elite male Gaelic Football and Hurling players. A cross sectional study of functional movement in Gaelic games at Elite and Sub-Elite level. Players were video recorded completing the Functional Movement Screen Tool and scored post-test. Comparisons were analysed using Mann-Whitney U tests. Field testing in team gym facility and university biomechanics laboratory. A total of 62 players were tested. This consisted of 41 Hurling, and 21 Gaelic Football players. 30 of these participants were deemed Elite and 32 were deemed Sub-Elite. The mean age of the sample was 22.15 ± 3.02 years. Functional Movement Screen (FMS). The FMS mean score for the sample was 15.56 ± 1.46. The Elite group (15.8 ± 1.58) scored higher than the Sub-Elite group (15.34 ± 1.31) but there was no significant difference between groups. This study provides normative reference values for Gaelic Players. Elite Gaelic Players perform no better than a young, active population in the FMS indicating a potential problem with the FMS as a measure. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Influence of Restraint Systems on Panel Behavior

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.

2011-01-01

When a panel is tested in uniaxial compression in a test machine, the boundary conditions are not quite the same as they would be if it were part of a complete structure. A restraint system may be used to simulate conditions found in a complete vehicle. Quantifying the quality of the restraint with only point-measurement devices can leave an inadequate characterization of the out-of-plane behavior. However, today s full-field displacement monitoring techniques allow for much more accurate views of the global panel deformation and strain, and therefore allow for a better understanding of panel behavior. In the current study, the behavior of a hat-stiffened and two rod-stiffened carbon-epoxy panels is considered. Panels were approximately 2 meters tall and 0.76 to 1.06 m wide. Unloaded edges were supported by knife edges and stiffeners were attached to a support structure at selected locations to restrain out-of-plane motion. A comparison is made between test results based on full-field measurements and analyses based on assumptions of boundary conditions of a completely rigid edge restraint and the absence of any edge restraint. Results indicate that motion at the restrained edges must be considered to obtain accurate test-analysis correlation.

Hemispheric specialization in quantification processes.

PubMed

Pasini, M; Tessari, A

2001-01-01

Three experiments were carried out to study hemispheric specialization for subitizing (the rapid enumeration of small patterns) and counting (the serial quantification process based on some formal principles). The experiments consist of numerosity identification of dot patterns presented in one visual field, with a tachistoscopic technique, or eye movements monitored through glasses, and comparison between centrally presented dot patterns and lateralized tachistoscopically presented digits. Our experiments show left visual field advantage in the identification and comparison tasks in the subitizing range, whereas right visual field advantage has been found in the comparison task for the counting range.

Experimental study of noise reduction for an unstiffened cylindrical model of an airplane fuselage

NASA Astrophysics Data System (ADS)

Willis, C. M.; Daniels, E. F.

1981-12-01

Noise reduction measurements were made for a simplified model of an airplane fuselage consisting of an unstiffened aluminum cylinder 0.5 m in diameter by 1.2 m long with a 1.6-mm-thick wall. Noise reduction was first measured with a reverberant field pink-noise load on the cylinder exterior. Next, noise reduction was measured by using a propeller to provide a more realistic noise load on the cylinder. Structural resonance frequencies and acoustic reverberation times for the cylinder interior volume were also measured. Comparison of data from the relatively simple test using reverberant-field noise with data from the more complex propeller-noise tests indicates some similarity in both the overall noise reduction and the spectral distribution. However, all of the test parameters investigated (propeller speed, blade pitch, and tip clearance) had some effect on the noise-reduction spectra. Thus, the amount of noise reduction achieved appears to be somewhat dependent upon the spectral and spatial characteristics of the flight conditions. Information is also presented on cyclinder resonance frequencies, damping, and characteristics of propeller-noise loads.

A noise control package for vibrating screens1),2)

PubMed Central

Lowe, M. Jenae; Yantek, David S.; Yang, Junyi; Schuster, Kevin C.; Mechling, Jessie J.

2015-01-01

Hearing loss was the second-most common illness reported to the Mine Safety and Health Administration (MSHA) in 2009. Furthermore, between 2000 and 2010, 30% of all noise-related injury complaints reported to MSHA were for coal preparation plant employees. Previous National Institute for Occupational Safety and Health (NIOSH) studies have shown that vibrating screens are key noise sources to address in order to reduce coal preparation plant noise. In response, NIOSH researchers have developed a suite of noise controls for vibrating screens consisting of constrained layer damping (CLD) treatments, a tuned mechanism suspension, an acoustic enclosure, and spring inserts. Laboratory testing demonstrates that this noise control suite reduces the A-weighted sound power level of the vibrating screen by 6 dB. To provide a comparison to laboratory results and prove durability, field testing of two noise controls was performed on a vibrating screen in a working coal preparation plant. The spring inserts and CLD treatments were selected due to their ease of installation and practicability. Field testing of these controls yielded reductions that were comparable to laboratory results. PMID:26257468

AE characteristic for monitoring of fatigue crack in steel bridge members

NASA Astrophysics Data System (ADS)

Yoon, Dong-Jin; Jung, Juong-Chae; Park, Philip; Lee, Seung-Seok

2000-06-01

Acoustic emission technique was employed for the monitoring of crack activity in both steel bridge members and laboratory specimen. Laboratory experiment was carried out to identify AE characteristics of fatigue cracks for compact tension specimen. The relationship between a stress intensity factor and AE signals activity as well as conventional AE parameter analysis was discussed. A field test was also conducted on a railway bridge, which contain several fatigue cracks. Crack activities were investigated while in service with strain measurement. From the results, in the laboratory tests, the features of three parameters such as the length of crack growth, the AE energy, and the cumulative AE events, showed the almost same trend in their increase as the number of fatigue cycle increased. From the comparisons of peak amplitude and AE energy with stress intensity factor, it was verified that the higher stress intensity factors generated AE signals with higher peak amplitude and a large number of AE counts. In the field test, real crack propagation signals were captured and the crack activity was verified in two cases.

Development of Rhizo-Columns for Nondestructive Root System Architecture Laboratory Measurements

NASA Astrophysics Data System (ADS)

Oostrom, M.; Johnson, T. J.; Varga, T.; Hess, N. J.; Wietsma, T. W.

2016-12-01

Numerical models for root water uptake in plant-soil systems have been developing rapidly, increasing the demand for laboratory experimental data to test and verify these models. Most of the increasingly detailed models are either compared to long-term field crop data or do not involve comparisons at all. Ideally, experiments would provide information on dynamic root system architecture (RSA) in combination with soil-pant hydraulics such as water pressures and volumetric water contents. Data obtained from emerging methods such as Spectral Induced Polarization (SIP) and x-ray computed tomography (x-ray CT) may be used to provide laboratory RSA data needed for model comparisons. Point measurements such as polymer tensiometers (PT) may provide soil moisture information over a large range of water pressures, from field capacity to the wilting point under drought conditions. In the presentation, we demonstrate a novel laboratory capability allowing for detailed RSA studies in large columns under controlled conditions using automated SIP, X-ray CT, and PT methods. Examples are shown for pea and corn root development under various moisture regimes.

Inversion algorithms for the microwave remote sensing of soil moisture. Experiments with swept frequency microwaves

NASA Technical Reports Server (NTRS)

Hancock, G. D.; Waite, W. P.

1984-01-01

Two experiments were performed employing swept frequency microwaves for the purpose of investigating the reflectivity from soil volumes containing both discontinuous and continuous changes in subsurface soil moisture content. Discontinuous moisture profiles were artificially created in the laboratory while continuous moisture profiles were induced into the soil of test plots by the environment of an agricultural field. The reflectivity for both the laboratory and field experiments was measured using bi-static reflectometers operated over the frequency ranges of 1.0 to 2.0 GHz and 4.0 to 8.0 GHz. Reflectivity models that considered the discontinuous and continuous moisture profiles within the soil volume were developed and compared with the results of the experiments. This comparison shows good agreement between the smooth surface models and the measurements. In particular the comparison of the smooth surface multi-layer model for continuous moisture profiles and the yield experiment measurements points out the sensitivity of the specular component of the scattered electromagnetic energy to the movement of moisture in the soil.

Uniocular and binocular fields of rotation measures: Octopus versus Goldmann.

PubMed

Rowe, Fiona J; Hanif, Sahira

2011-06-01

To compare the range of ocular rotations measured by Octopus versus Goldmann perimetry. Forty subjects (20 controls and 20 patients with impaired ocular movements) were prospectively recruited, age range 21-83 years. Range of uniocular rotations was measured in six vectors corresponding to extraocular muscle actions: 0°, 67°, 141°, 180°, 216°, 293°. Fields of binocular single vision were assessed at 30° intervals. Vector measurements were utilised to calculate an area score for the field of uniocular rotations or binocular field of single vision. Two test speeds were used for Octopus testing: 3°/ and 10°/second. Test duration was two thirds quicker for Octopus 10°/second than for 3°/second stimulus speed, and slightly quicker for Goldmann. Mean area for control subjects for uniocular field was 7910.45 degrees(2) for Goldmann, 7032.14 for Octopus 3°/second and 7840.66 for Octopus 10°/second. Mean area for patient subjects of right uniocular field was 8567.21 degrees(2) for Goldmann, 5906.72 for Octopus 3°/second and 8806.44 for Octopus 10°/second. Mean area for left uniocular field was 8137.49 degrees(2) for Goldmann, 8127.9 for Octopus 3°/second and 8950.54 for Octopus 10°/second. Range of measured rotation was significantly larger for Octopus 10°/second speed. Our results suggest that the Octopus perimeter is an acceptable alternative method of assessment for uniocular ductions and binocular field of single vision. Speed of stimulus significantly alters test duration for Octopus perimetry. Comparisons of results from both perimeters show that quantitative measurements differ, although qualitatively the results are similar. Differences per mean vectors were less than 5° (within clinically accepted variances) for both controls and patients when comparing Goldmann to Octopus 10°/second speed. However, differences were almost 10° for the patient group when comparing Goldmann to Octopus 3°/second speed. Thus, speed of stimulus must be considered if wishing to use these perimeters interchangeably.

Are radiosensitivity data derived from natural field conditions consistent with data from controlled exposures? A case study of Chernobyl wildlife chronically exposed to low dose rates.

PubMed

Garnier-Laplace, J; Geras'kin, S; Della-Vedova, C; Beaugelin-Seiller, K; Hinton, T G; Real, A; Oudalova, A

2013-07-01

The discrepancy between laboratory or controlled conditions ecotoxicity tests and field data on wildlife chronically exposed to ionising radiation is presented for the first time. We reviewed the available chronic radiotoxicity data acquired in contaminated fields and used a statistical methodology to support the comparison with knowledge on inter-species variation of sensitivity to controlled external γ irradiation. We focus on the Chernobyl Exclusion Zone and effects data on terrestrial wildlife reported in the literature corresponding to chronic dose rate exposure situations (from background ~100 nGy/h up to ~10 mGy/h). When needed, we reconstructed the dose rate to organisms and obtained consistent unbiased data sets necessary to establish the dose rate-effect relationship for a number of different species and endpoints. Then, we compared the range of variation of radiosensitivity of species from the Chernobyl-Exclusion Zone with the statistical distribution established for terrestrial species chronically exposed to purely gamma external irradiation (or chronic Species radioSensitivity Distribution - SSD). We found that the best estimate of the median value (HDR50) of the distribution established for field conditions at Chernobyl (about 100 μGy/h) was eight times lower than the one from controlled experiments (about 850 μGy/h), suggesting that organisms in their natural environmental were more sensitive to radiation. This first comparison highlights the lack of mechanistic understanding and the potential confusion coming from sampling strategies in the field. To confirm the apparent higher sensitive of wildlife in the Chernobyl Exclusion Zone, we call for more a robust strategy in field, with adequate design to deal with confounding factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sequential Bayesian Geostatistical Inversion and Evaluation of Combined Data Worth for Aquifer Characterization at the Hanford 300 Area

NASA Astrophysics Data System (ADS)

Murakami, H.; Chen, X.; Hahn, M. S.; Over, M. W.; Rockhold, M. L.; Vermeul, V.; Hammond, G. E.; Zachara, J. M.; Rubin, Y.

2010-12-01

Subsurface characterization for predicting groundwater flow and contaminant transport requires us to integrate large and diverse datasets in a consistent manner, and quantify the associated uncertainty. In this study, we sequentially assimilated multiple types of datasets for characterizing a three-dimensional heterogeneous hydraulic conductivity field at the Hanford 300 Area. The datasets included constant-rate injection tests, electromagnetic borehole flowmeter tests, lithology profile and tracer tests. We used the method of anchored distributions (MAD), which is a modular-structured Bayesian geostatistical inversion method. MAD has two major advantages over the other inversion methods. First, it can directly infer a joint distribution of parameters, which can be used as an input in stochastic simulations for prediction. In MAD, in addition to typical geostatistical structural parameters, the parameter vector includes multiple point values of the heterogeneous field, called anchors, which capture local trends and reduce uncertainty in the prediction. Second, MAD allows us to integrate the datasets sequentially in a Bayesian framework such that it updates the posterior distribution, as a new dataset is included. The sequential assimilation can decrease computational burden significantly. We applied MAD to assimilate different combinations of the datasets, and then compared the inversion results. For the injection and tracer test assimilation, we calculated temporal moments of pressure build-up and breakthrough curves, respectively, to reduce the data dimension. A massive parallel flow and transport code PFLOTRAN is used for simulating the tracer test. For comparison, we used different metrics based on the breakthrough curves not used in the inversion, such as mean arrival time, peak concentration and early arrival time. This comparison intends to yield the combined data worth, i.e. which combination of the datasets is the most effective for a certain metric, which will be useful for guiding the further characterization effort at the site and also the future characterization projects at the other sites.

Validation of a Rapid Rabies Diagnostic Tool for Field Surveillance in Developing Countries

PubMed Central

Léchenne, Monique; Naïssengar, Kemdongarti; Lepelletier, Anthony; Alfaroukh, Idriss Oumar; Bourhy, Hervé; Zinsstag, Jakob; Dacheux, Laurent

2016-01-01

Background One root cause of the neglect of rabies is the lack of adequate diagnostic tests in the context of low income countries. A rapid, performance friendly and low cost method to detect rabies virus (RABV) in brain samples will contribute positively to surveillance and consequently to accurate data reporting, which is presently missing in the majority of rabies endemic countries. Methodology/Principal findings We evaluated a rapid immunodiagnostic test (RIDT) in comparison with the standard fluorescent antibody test (FAT) and confirmed the detection of the viral RNA by real time reverse transcription polymerase chain reaction (RT-qPCR). Our analysis is a multicentre approach to validate the performance of the RIDT in both a field laboratory (N’Djamena, Chad) and an international reference laboratory (Institut Pasteur, Paris, France). In the field laboratory, 48 samples from dogs were tested and in the reference laboratory setting, a total of 73 samples was tested, representing a wide diversity of RABV in terms of animal species tested (13 different species), geographical origin of isolates with special emphasis on Africa, and different phylogenetic clades. Under reference laboratory conditions, specificity was 93.3% and sensitivity was 95.3% compared to the gold standard FAT test. Under field laboratory conditions, the RIDT yielded a higher reliability than the FAT test particularly on fresh and decomposed samples. Viral RNA was later extracted directly from the test filter paper and further used successfully for sequencing and genotyping. Conclusion/Significance The RIDT shows excellent performance qualities both in regard to user friendliness and reliability of the result. In addition, the test cassettes can be used as a vehicle to ship viral RNA to reference laboratories for further laboratory confirmation of the diagnosis and for epidemiological investigations using nucleotide sequencing. The potential for satisfactory use in remote locations is therefore very high to improve the global knowledge of rabies epidemiology. However, we suggest some changes to the protocol, as well as careful further validation, before promotion and wider use. PMID:27706156

Chemical composition and antioxidant property of holy basil (Ocimum sanctum L.) leaves, stems, and inflorescence and their in vitro callus cultures.

PubMed

Hakkim, F Lukmanul; Shankar, C Gowri; Girija, S

2007-10-31

In this study, the chemical constituents and antioxidant property of holy basil (Ocimum sanctum Linn.) field-grown plant parts (leaves, stems, and inflorescence) were compared with those of respective callus cultures induced from each explant in in vitro. The callus cultures were successfully initiated on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D) (1 mg/L) combined with different concentrations (0.1-0.5 mg/L) of kinetin as plant growth regulators. The distribution of phenolic compounds in these extracts was analyzed using reverse phase high-performance liquid chromatography with reference standards. Interestingly, rosmarinic acid (RA) was found to be the predominant phenolic acid in all callus extracts in comparison with field-grown plant parts. In this study, the antioxidant activity of the extracts was evaluated with six different in vitro antioxidant-testing systems. Their activities of scavenging superoxide anion radicals, 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), hydroxyl radicals, hydrogen peroxide, chelating ferrous iron, and ferric ion reducing potential were assessed. The antioxidant activity was increased in all testing systems with increasing amounts of extract. However, at the same concentration, the callus extracts exhibited higher antioxidant activity in all of the testing systems than the extract obtained from field-grown plant parts. The data obtained from this study suggested the possibility of the isolation of a high content of RA from in vitro callus cultures rather than field-grown plant organs of holy basil.

Impact Response Comparison Between Parametric Human Models and Postmortem Human Subjects with a Wide Range of Obesity Levels.

PubMed

Zhang, Kai; Cao, Libo; Wang, Yulong; Hwang, Eunjoo; Reed, Matthew P; Forman, Jason; Hu, Jingwen

2017-10-01

Field data analyses have shown that obesity significantly increases the occupant injury risks in motor vehicle crashes, but the injury assessment tools for people with obesity are largely lacking. The objectives of this study were to use a mesh morphing method to rapidly generate parametric finite element models with a wide range of obesity levels and to evaluate their biofidelity against impact tests using postmortem human subjects (PMHS). Frontal crash tests using three PMHS seated in a vehicle rear seat compartment with body mass index (BMI) from 24 to 40 kg/m 2 were selected. To develop the human models matching the PMHS geometry, statistical models of external body shape, rib cage, pelvis, and femur were applied to predict the target geometry using age, sex, stature, and BMI. A mesh morphing method based on radial basis functions was used to rapidly morph a baseline human model into the target geometry. The model-predicted body excursions and injury measures were compared to the PMHS tests. Comparisons of occupant kinematics and injury measures between the tests and simulations showed reasonable correlations across the wide range of BMI levels. The parametric human models have the capability to account for the obesity effects on the occupant impact responses and injury risks. © 2017 The Obesity Society.

A CCD Color Comparison of Seyfert 1 and 2 Host Galaxies

NASA Astrophysics Data System (ADS)

Virani, S. N.; De Robertis, M. M.

2001-05-01

Wide-field, R-band CCD data of 15 Seyfert 1 and 15 Seyfert 2 galaxies taken from the CfA survey were analysed in order to compare the properties of their host galaxies. Also, B-band images for a subset of 12 Seyfert 1s and 7 Seyfert 2s were acquired and analysed in the same way. The nuclear contribution of the Seyfert host galaxies was modeled and removed empirically by using a robust technique for decomposing the nucleus, bulge and disk components (see Virani et al. 2000, De Robertis and Virani, 2001). Profile fits to the remaining bulge+disk light were then performed. Of the many B-R color comparisons that were performed (i.e., component colors, color gradient, etc.) between Seyfert 1s and 2s, only two distributions differed at greater than the 95% confidence level for the K-S test: the magnitude of the nuclear component, and the radial color gradient outside the nucleus. The former is expected. The latter could be consistent with some proposed evolutionary models. There is some suggestion that other parameters may differ, but at a lower confidence level. Color contour maps and results from all tests performed (K-S test and Wilcoxon-Rank Sum Test) are presented.

V/STOL and STOL ground effects and testing techniques

NASA Technical Reports Server (NTRS)

Kuhn, R. E.

1987-01-01

The ground effects associated with V/STOL operation were examined and an effort was made to develop the equipment and testing techniques needed for that understanding. Primary emphasis was on future experimental programs in the 40 x 80 and the 80 x 120 foot test sections and in the outdoor static test stand associated with these facilities. The commonly used experimental techniques are reviewed and data obtained by various techniques are compared with each other and with available estimating methods. These reviews and comparisons provide insight into the limitations of past studies and the testing techniques used and identify areas where additional work is needed. The understanding of the flow mechanics involved in hovering and in transition in and out of ground effect is discussed. The basic flow fields associated with hovering, transition and STOL operation of jet powered V/STOL aircraft are depicted.

Impairment of exploratory behavior and spatial memory in adolescent rats in lithium-pilocarpine model of temporal lobe epilepsy.

PubMed

Kalemenev, S V; Zubareva, O E; Frolova, E V; Sizov, V V; Lavrentyeva, V V; Lukomskaya, N Ya; Kim, K Kh; Zaitsev, A V; Magazanik, L G

2015-01-01

Cognitive impairment in six-week -old rats has been studied in the lithium-pilocarpine model of adolescent temporal lobe epilepsy in humans. The pilocarpine-treated rats (n =21) exhibited (a) a decreased exploratory activity in comparison with control rats (n = 20) in the open field (OP) test and (b) a slower extinction of exploratory behavior in repeated OP tests. The Morris Water Maze (MWM) test showed that the effect of training was less pronounced in the pilocarpine-treated rats, which demonstrated disruption of predominantly short-term memory. Therefore, our study has shown that lithium-pilocarpine seizures induce substantial changes in exploratory behavior and spatial memory in adolescent rats. OP and MWM tests can be used in the search of drugs reducing cognitive impairments associated with temporal lobe epilepsy.

How Well Does the S-Web Theory Predict In-Situ Observations of the Slow Solar Wind?

NASA Astrophysics Data System (ADS)

Young, A. K.; Antiochos, S. K.; Linker, J.; Zurbuchen, T.

2014-12-01

The S-Web theory provides a physical explanation for the origin and properties of the slow solar wind, particularly its composition. The theory proposes that magnetic reconnection along topologically complex boundaries between open and closed magnetic fields on the sun releases plasma from closed magnetic field regions into the solar wind at latitudes away from the heliospheric current sheet. Such a wind would have elevated charge states compared to the fast wind and an elemental composition resembling the closed-field corona. This theory is currently being tested using time-dependent, high-resolution, MHD simulations, however comparisons to in-situ observations play an essential role in testing and understanding slow-wind release mechanisms. In order to determine the relationship between S-Web signatures and the observed, slow solar wind, we compare plasma data from the ACE and Ulysses spacecraft to solutions from the steady-state models created at Predictive Science, Inc., which use observed magnetic field distributions on the sun as a lower boundary condition. We discuss the S-Web theory in light of our results and the significance of the S-Web for interpreting current and future solar wind observations. This work was supported, in part, by the NASA TR&T and SR&T programs.

Yield estimation of corn with multispectral data and the potential of using imaging spectrometers

NASA Astrophysics Data System (ADS)

Bach, Heike

1997-05-01

In the frame of the special yield estimation, a regular procedure conducted for the European Union to more accurately estimate agricultural yield, a project was conducted for the state minister for Rural Environment, Food and Forestry of Baden-Wuerttemberg, Germany) to test remote sensing data with advanced yield formation models for accuracy and timelines of yield estimation of corn. The methodology employed uses field-based plant parameter estimation from atmospherically corrected multitemporal/multispectral LANDSAT-TM data. An agrometeorological plant-production-model is used for yield prediction. Based solely on 4 LANDSAT-derived estimates and daily meteorological data the grain yield of corn stands was determined for 1995. The modeled yield was compared with results independently gathered within the special yield estimation for 23 test fields in the Upper Rhine Valley. The agrement between LANDSAT-based estimates and Special Yield Estimation shows a relative error of 2.3 percent. The comparison of the results for single fields shows, that six weeks before harvest the grain yield of single corn fields was estimated with a mean relative accuracy of 13 percent using satellite information. The presented methodology can be transferred to other crops and geographical regions. For future applications hyperspectral sensors show great potential to further enhance the results or yield prediction with remote sensing.

Comparability between various field and laboratory wood-stove emission-measurement methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCrillis, R.C.; Jaasma, D.R.

1991-01-01

The paper compares various field and laboratory woodstove emission measurement methods. In 1988, the U.S. EPA promulgated performance standards for residential wood heaters (woodstoves). Over the past several years, a number of field studies have been undertaken to determine the actual level of emission reduction achieved by new technology woodstoves in everyday use. The studies have required the development and use of particulate and gaseous emission sampling equipment compatible with operation in private homes. Since woodstoves are tested for certification in the laboratory using EPA Methods 5G and 5H, it is of interest to determine the correlation between these regulatorymore » methods and the inhouse equipment. Two inhouse sampling systems have been used most widely: one is an intermittent, pump-driven particulate sampler that collects particulate and condensible organics on a filter and organic adsorbent resin; and the other uses an evacuated cylinder as the motive force and particulate and condensible organics are collected in a condenser and dual filter. Both samplers can operate unattended for 1-week periods. A large number of tests have been run comparing Methods 5G and 5H to both samplers. The paper presents these comparison data and determines the relationships between regulations and field samplers.« less

Fabric filter model sensitivity analysis. Final report Jun 1978-Feb 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis, R.; Klemm, H.A.; Battye, W.

1979-04-01

The report gives results of a series of sensitivity tests of a GCA fabric filter model, as a precursor to further laboratory and/or field tests. Preliminary tests had shown good agreement with field data. However, the apparent agreement between predicted and actual values was based on limited comparisons: validation was carried out without regard to optimization of the data inputs selected by the filter users or manufactures. The sensitivity tests involved introducing into the model several hypothetical data inputs that reflect the expected ranges in the principal filter system variables. Such factors as air/cloth ratio, cleaning frequency, amount of cleaning,more » specific resistence coefficient K2, the number of compartments, and inlet concentration were examined in various permutations. A key objective of the tests was to determine the variables that require the greatest accuracy in estimation based on their overall impact on model output. For K2 variations, the system resistance and emission properties showed little change; but the cleaning requirement changed drastically. On the other hand, considerable difference in outlet dust concentration was indicated when the degree of fabric cleaning was varied. To make the findings more useful to persons assessing the probable success of proposed or existing filter systems, much of the data output is presented in graphs or charts.« less

Journal: A Review of Some Tracer-Test Design Equations for ...

EPA Pesticide Factsheets

Determination of necessary tracer mass, initial sample-collection time, and subsequent sample-collection frequency are the three most difficult aspects to estimate for a proposed tracer test prior to conducting the tracer test. To facilitate tracer-mass estimation, 33 mass-estimation equations are reviewed here, 32 of which were evaluated using previously published tracer-test design examination parameters. Comparison of the results produced a wide range of estimated tracer mass, but no means is available by which one equation may be reasonably selected over the others. Each equation produces a simple approximation for tracer mass. Most of the equations are based primarily on estimates or measurements of discharge, transport distance, and suspected transport times. Although the basic field parameters commonly employed are appropriate for estimating tracer mass, the 33 equations are problematic in that they were all probably based on the original developers' experience in a particular field area and not necessarily on measured hydraulic parameters or solute-transport theory. Suggested sampling frequencies are typically based primarily on probable transport distance, but with little regard to expected travel times. This too is problematic in that tends to result in false negatives or data aliasing. Simulations from the recently developed efficient hydrologic tracer-test design methodology (EHTD) were compared with those obtained from 32 of the 33 published tracer-

A comparison of two adaptive multivariate analysis methods (PLSR and ANN) for winter wheat yield forecasting using Landsat-8 OLI images

NASA Astrophysics Data System (ADS)

Chen, Pengfei; Jing, Qi

2017-02-01

An assumption that the non-linear method is more reasonable than the linear method when canopy reflectance is used to establish the yield prediction model was proposed and tested in this study. For this purpose, partial least squares regression (PLSR) and artificial neural networks (ANN), represented linear and non-linear analysis method, were applied and compared for wheat yield prediction. Multi-period Landsat-8 OLI images were collected at two different wheat growth stages, and a field campaign was conducted to obtain grain yields at selected sampling sites in 2014. The field data were divided into a calibration database and a testing database. Using calibration data, a cross-validation concept was introduced for the PLSR and ANN model construction to prevent over-fitting. All models were tested using the test data. The ANN yield-prediction model produced R2, RMSE and RMSE% values of 0.61, 979 kg ha-1, and 10.38%, respectively, in the testing phase, performing better than the PLSR yield-prediction model, which produced R2, RMSE, and RMSE% values of 0.39, 1211 kg ha-1, and 12.84%, respectively. Non-linear method was suggested as a better method for yield prediction.

Predictive testing and existential absurdity: resonances between experiences around genetic diagnosis and the philosophy of Albert Camus.

PubMed

Porz, Rouven; Widdershoven, Guy

2011-07-01

Predictive genetic testing may confront those affected with difficult life situations that they have not experienced before. These life situations may be interpreted as 'absurd'. In this paper we present a case study of a predictive test situation, showing the perspective of a woman going through the process of deciding for or against taking the test, and struggling with feelings of alienation. To interpret her experiences, we refer to the concept of absurdity, developed by the French Philosopher Albert Camus. Camus' writings on absurdity appear to resonate with patients' stories when they talk about their body and experiences of illness. In this paper we draw on Camus' philosophical essay 'The Myth of Sisyphus' (1942), and compare the absurd experiences of Sisyphus with the interviewee's story. This comparison opens up a field of ethical reflection. We demonstrate that Camus' concept of absurdity offers a new and promising approach to understanding the fragility of patients' situations, especially in the field of predictive testing. We show that people affected might find new meaning through narratives that help them to reconstruct the absurd without totally overcoming it. In conclusion, we will draw out some normative consequences of our narrative approach. © 2009 Blackwell Publishing Ltd.

The choice of statistical methods for comparisons of dosimetric data in radiotherapy.

PubMed

Chaikh, Abdulhamid; Giraud, Jean-Yves; Perrin, Emmanuel; Bresciani, Jean-Pierre; Balosso, Jacques

2014-09-18

Novel irradiation techniques are continuously introduced in radiotherapy to optimize the accuracy, the security and the clinical outcome of treatments. These changes could raise the question of discontinuity in dosimetric presentation and the subsequent need for practice adjustments in case of significant modifications. This study proposes a comprehensive approach to compare different techniques and tests whether their respective dose calculation algorithms give rise to statistically significant differences in the treatment doses for the patient. Statistical investigation principles are presented in the framework of a clinical example based on 62 fields of radiotherapy for lung cancer. The delivered doses in monitor units were calculated using three different dose calculation methods: the reference method accounts the dose without tissues density corrections using Pencil Beam Convolution (PBC) algorithm, whereas new methods calculate the dose with tissues density correction for 1D and 3D using Modified Batho (MB) method and Equivalent Tissue air ratio (ETAR) method, respectively. The normality of the data and the homogeneity of variance between groups were tested using Shapiro-Wilks and Levene test, respectively, then non-parametric statistical tests were performed. Specifically, the dose means estimated by the different calculation methods were compared using Friedman's test and Wilcoxon signed-rank test. In addition, the correlation between the doses calculated by the three methods was assessed using Spearman's rank and Kendall's rank tests. The Friedman's test showed a significant effect on the calculation method for the delivered dose of lung cancer patients (p <0.001). The density correction methods yielded to lower doses as compared to PBC by on average (-5 ± 4.4 SD) for MB and (-4.7 ± 5 SD) for ETAR. Post-hoc Wilcoxon signed-rank test of paired comparisons indicated that the delivered dose was significantly reduced using density-corrected methods as compared to the reference method. Spearman's and Kendall's rank tests indicated a positive correlation between the doses calculated with the different methods. This paper illustrates and justifies the use of statistical tests and graphical representations for dosimetric comparisons in radiotherapy. The statistical analysis shows the significance of dose differences resulting from two or more techniques in radiotherapy.

Comparison of dialysis membrane diffusion samplers and two purging methods in bedrock wells

USGS Publications Warehouse

Imbrigiotta, T.E.; Ehlke, T.A.; Lacombe, P.J.; Dale, J.M.; ,

2002-01-01

Collection of ground-water samples from bedrock wells using low-flow purging techniques is problematic because of the random spacing, variable hydraulic conductivity, and variable contamination of contributing fractures in each well's open interval. To test alternatives to this purging method, a field comparison of three ground-water-sampling techniques was conducted on wells in fractured bedrock at a site contaminated primarily with volatile organic compounds. Constituent concentrations in samples collected with a diffusion sampler constructed from dialysis membrane material were compared to those in samples collected from the same wells with a standard low-flow purging technique and a hybrid (high-flow/low-flow) purging technique. Concentrations of trichloroethene, cis-1,2-dichloroethene, vinyl chloride, calcium, chloride, and alkalinity agreed well among samples collected with all three techniques in 9 of the 10 wells tested. Iron concentrations varied more than those of the other parameters, but their pattern of variation was not consistent. Overall, the results of nonparametric analysis of variance testing on the nine wells sampled twice showed no statistically significant difference at the 95-percent confidence level among the concentrations of volatile organic compounds or inorganic constituents recovered by use of any of the three sampling techniques.

A detailed numerical simulation of a liquid-propellant rocket engine ground test experiment

NASA Astrophysics Data System (ADS)

Lankford, D. W.; Simmons, M. A.; Heikkinen, B. D.

1992-07-01

A computational simulation of a Liquid Rocket Engine (LRE) ground test experiment was performed using two modeling approaches. The results of the models were compared with selected data to assess the validity of state-of-the-art computational tools for predicting the flowfield and radiative transfer in complex flow environments. The data used for comparison consisted of in-band station radiation measurements obtained in the near-field portion of the plume exhaust. The test article was a subscale LRE with an afterbody, resulting in a large base region. The flight conditions were such that afterburning regions were observed in the plume flowfield. A conventional standard modeling approach underpredicted the extent of afterburning and the associated radiation levels. These results were attributed to the absence of the base flow region which is not accounted for in this model. To assess the effects of the base region a Navier-Stokes model was applied. The results of this calculation indicate that the base recirculation effects are dominant features in the immediate expansion region and resulted in a much improved comparison. However, the downstream in-band station radiation data remained underpredicted by this model.

Prediction of Plasticity Characteristics for Three-Dimensional Fracture Specimens Comparison with Experiment,

DTIC Science & Technology

1985-01-01

ILlHoHil 1 .8W I1111 IL25 JJJ . 4 11J . MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS-1963-A ,I 4 . .. .. . . . . . .--. ,- -- ,-...f...measuring the different sides is discussed. 1...8217. : . .’." .:..".. ". ... .’.. .".. .".. ".".".".. .,."....... .,’. .".. .,. ’’,.’.’ . ,.. 4 :’:.’.: ,-:2,2-> .. . . . r*- . INTRODUCTION Over the past 35 years, the field of fracture mechanics has evolved and developed into an

Modeling of Army Research Laboratory EMP simulators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miletta, J.R.; Chase, R.J.; Luu, B.B.

1993-12-01

Models are required that permit the estimation of emitted field signatures from EMP simulators to design the simulator antenna structure, to establish the usable test volumes, and to estimate human exposure risk. This paper presents the capabilities and limitations of a variety of EMP simulator models useful to the Army's EMP survivability programs. Comparisons among frequency and time-domain models are provided for two powerful US Army Research Laboratory EMP simulators: AESOP (Army EMP Simulator Operations) and VEMPS II (Vertical EMP Simulator II).

Comparison of contractile and extensile pneumatic artificial muscles

NASA Astrophysics Data System (ADS)

Pillsbury, Thomas E.; Wereley, Norman M.; Guan, Qinghua

2017-09-01

Pneumatic artificial muscles (PAMs) are used in robotic and prosthetic applications due to their high power to weight ratio, controllable compliance, and simple design. Contractile PAMs are typically used in traditional hard robotics in place of heavy electric motors. As the field of soft robotics grows, extensile PAMs are beginning to have increased usage. This work experimentally tests, models, and compares contractile and extensile PAMs to demonstrate the advantages and disadvantages of each type of PAM and applications for which they are best suited.

Comparison of anesthetic agents in the sea otter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, T.D.; Kocher, F.H.

Five anesthetic agents (CI744, etorphine, fentanyl, ketamine hydrochloride, and halothane) were tested to establish the dosage of a safe, effective, short-acting anesthetic for use in the sea otter. Etorphine, at a dosage of 0.75 mg per adult otter and used in conjunction with diazepam, at a dosage of 1.25 mg per adult otter, met most of the requirements for use under field conditions. Halothane, administered through an anesthetic machine, proved to be effective for use in a veterinary hospital.

Radio Wave Propagation: A Handbook of Practical Techniques for Computing Basic Transmission Loss and Field Strength

DTIC Science & Technology

1982-09-01

MARK A. WEISSBEGU KALLE R. XONTSON Project Msnaqer, IUTRZ Assistant Director Contractor Operations Approved by CRARLES L. FLYNN, 001, us A. M. MESSE...34 BSTJ, 1946. 2-4priis, H.T., "Introduction to Radio and Antennas," IEEE Spectrum, April, 1971 . RADIO WAVE PROPAGATION: A HANDBOOK OF PRACTICAL...Propagation Tests, TR-0177-71.01, Gautney & Jones Communications, Inc., Falls Church, VA, June 1971 . 3 -7 Comparison of Predicted VLF/LF Signal

Preliminary Comparison of March-May Radiosonde Soundings with March-May Climatological Profiles for Yuma, Arizona

DTIC Science & Technology

2017-02-01

difference from the climate -based METCM. The Tv changes are shown in Fig. 5, but given the smaller relative changes only the ±2 SD curves are presented...planning and in field tests when sounding data are not available. However, the use of climate mean profiles may lead to wide differences from actual...individual atmospheric profiles. This brief report investigates the variation of a series of soundings as compared to climate mean soundings and

Optimizing the HRP-2 In Vitro Malaria Drug Susceptibility Assay Using a Reference Clone to Improve Comparisons of Plasmodium falciparum Field Isolates

DTIC Science & Technology

2012-09-13

6. Desjardins RE, Canfield CJ, Haynes JD, Chulay JD: Quantitative assessment of antimalarial activity in vitro by a semiautomated microdilution...vitro antimalarial drug efficacy testing and application to clinical isolates. Antimicrob Agents Chemother 2007, 51:1172–1178. 12. Akala HM, Eyase FL...Cheruiyot AC, Omondi AA, Ogutu BR, Waters NC, Johnson JD, Polhemus ME, Schnabel DC, Walsh DS: Antimalarial drug sensitivity profile of western Kenya

Propeller flow visualization techniques

NASA Technical Reports Server (NTRS)

Stefko, G. L.; Paulovich, F. J.; Greissing, J. P.; Walker, E. D.

1982-01-01

Propeller flow visualization techniques were tested. The actual operating blade shape as it determines the actual propeller performance and noise was established. The ability to photographically determine the advanced propeller blade tip deflections, local flow field conditions, and gain insight into aeroelastic instability is demonstrated. The analytical prediction methods which are being developed can be compared with experimental data. These comparisons contribute to the verification of these improved methods and give improved capability for designing future advanced propellers with enhanced performance and noise characteristics.

Reverberance of AN Existing Hall in Relation to both Subsequent Reverberation Time and Spl

NASA Astrophysics Data System (ADS)

HASE, S.; TAKATSU, A.; SATO, S.; SAKAI, H.; ANDO, Y.

2000-04-01

The reverberance of sound fields was evaluated by psychological tests in a multi-purpose hall with 400 seats. Both the subsequent reverberation time (Tsub) and sound pressure level (SPL) were changed, and the scale values of reverberance for both the music and speech signals were obtained by using the paired comparison method. This study found that Tsuband SPL have an independent influence on the scale value of reverberance. The reverberance increases when both Tsuband SPL are increased.

Near-Millimeter Wave Technology Base Study: Volume I. Propagation and Target/Background Characteristics

DTIC Science & Technology

1979-11-01

diameter test cell used for laser propagation measurements is Path length-84 m to 2.0 km available and has been designed for circulating aerosols or...36- and 110-GHz and found an attenuation ratio of comparison measurements along a 4-km path with rain rate measured near the receiver end. a *02 They...time. Tipping-bucket systems . gauges are reliable, but become increasingly in- accurate at high rates . Flow gauges which The direct field measurement

Predicting the toxicity of sediment-associated trace metals with simultaneously extracted trace metal: Acid-volatile sulfide concentrations and dry weight-normalized concentrations: A critical comparison

USGS Publications Warehouse

Long, E.R.; MacDonald, D.D.; Cubbage, J.C.; Ingersoll, C.G.

1998-01-01

The relative abilities of sediment concentrations of simultaneously extracted trace metal: acid-volatile sulfide (SEM: AVS) and dry weight-normalized trace metals to correctly predict both toxicity and nontoxicity were compared by analysis of 77 field-collected samples. Relative to the SEM:AVS concentrations, sediment guidelines based upon dry weight-normalized concentrations were equally or slightly more accurate in predicting both nontoxic and toxic results in laboratory tests.

A Comparison of Three-Dimensional Simulations of Traveling-Wave Tube Cold-Test Characteristics Using CST MICROWAVE STUDIO and MAFIA

NASA Technical Reports Server (NTRS)

Chevalier, C. T.; Herrmann, K. A.; Kory, C. L.; Wilson, J. D.; Cross, A. W.; Williams, W. D. (Technical Monitor)

2001-01-01

Previously, it was shown that MAFIA (solutions of Maxwell's equations by the Finite Integration Algorithm), a three-dimensional simulation code, can be used to produce accurate cold-test characteristics including frequency-phase dispersion, interaction impedance, and attenuation for traveling-wave tube (TWT) slow-wave structures. In an effort to improve user-friendliness and simulation time, a model was developed to compute the cold-test parameters using the electromagnetic field simulation software package CST MICROWAVE STUDIO (MWS). Cold-test parameters were calculated for several slow-wave circuits including a ferruled coupled-cavity, a folded waveguide, and a novel finned-ladder circuit using both MWS and MAFIA. Comparisons indicate that MWS provides more accurate cold-test data with significantly reduced simulation times. Both MAFIA and MWS are based on the finite integration (FI) method; however, MWS has several advantages over MAFIA. First, it has a Windows based interface for PC operation, making it very user-friendly, whereas MAFIA is UNIX based. MWS uses a new Perfect Boundary Approximation (PBA), which increases the accuracy of the simulations by avoiding stair step approximations associated with MAFIA's representation of structures. Finally, MWS includes a Visual Basic for Applications (VBA) compatible macro language that enables the simulation process to be automated and allows for the optimization of user-defined goal functions, such as interaction impedance.

Saccadic eye movements as a measure of residual effects: temazepam compared with other hypnotics.

PubMed

Hofferberth, B; Hirschberg; Grotemeyer

1986-01-01

Eye movements are classified into two categories: quickly running saccades and smooth pursuit movements. Saccades are fast conjugate eye movements with a preprogrammed direction, amplitude, and speed course; their purpose is to register new objects in the visual field. The duration and velocity of saccadic eye movements are very much dependent on vigilance. Comparisons were made with a number of psychometric tests [d 2 Durchstreichtest (cross out test), Viennese determination apparatus, and flicker fusion frequency] and the velocity of fast eye movements. The results of three separate investigations are presented. Standardization was undertaken in 100 healthy volunteers, 50 male and 50 female subjects aged between 20 and more than 50 years were included. In an open parallel group study, comparisons were made between various hypnotics with different half-lives (temazepam, flunitrazepam, flurazepam, and phenobarbital). There were 10 healthy volunteers in each group, and medication was taken as a single night-time dose for 7 nights. In a double-blind study, temazepam (20 mg/day) was tested against flunitrazepam (2 mg/day). Dosing lasted 7 days. A marked impairment of the saccadic eye movements was observed with flunitrazepam but not with temazepam. Of all the benzodiazepines tested, only temazepam had no influence on the parameters of the saccade test. These results can be explained by temazepam's short half-life and also by the fact that no active metabolites are formed.

Influence of the configuration of the magnetic filter field on the discharge structure in the RF driven negative ion source prototype for fusion

NASA Astrophysics Data System (ADS)

Lishev, S.; Schiesko, L.; Wünderlich, D.; Fantz, U.

2017-08-01

The study provides results for the influence of the filter field topology on the plasma parameters in the RF prototype negative ion source for ITER NBI. A previously developed 2D fluid plasma model of the prototype source was extended towards accounting for the particles and energy losses along the magnetic field lines and the presence of a magnetic field in the driver which is the case at the BATMAN and ELISE test-beds. The effect of the magnetic field in the driver is shown for the magnetic field configuration of the prototype source (i.e. a magnetic field produced by an external magnet frame) by comparison of plasma parameters without and with the magnetic field in the driver and for different axial positions of the filter. Since the ELISE-like magnetic field (i.e. a magnetic field produced by a current flowing through the plasma grid) is a new feature planned to be installed at the BATMAN test-bed, its effect on the discharge structure was studied for different strengths of the magnetic field. The obtained results show for both configurations of the magnetic filter the same main features in the patterns of the plasma parameters in the expansion chamber: a strong axial drop of the electron temperature and the formation of a groove accompanied with accumulation of electrons in front of the plasma grid. The presence of a magnetic field in the driver has a local impact on the plasma parameters: the formation of a second groove of the electron temperature in the case of BATMAN (due to the reversed direction of the filter field in the driver) and a strong asymmetry of the electron density. Accounting for the additional losses in the third dimension suppresses the drifts across the magnetic field and, thus, the variations of the electron density in the expansion chamber are less pronounced.

The mean magnetic field of the sun - Method of observation and relation to the interplanetary magnetic field

NASA Technical Reports Server (NTRS)

Scherrer, P. H.; Wilcox, J. M.; Kotov, V.; Severnyi, A. B.; Howard, R.

1977-01-01

The mean solar magnetic field as measured in integrated light has been observed since 1968. Since 1970 it has been observed both at Hale Observatories and at the Crimean Astrophysical Observatory. The observing procedures at both observatories and their implications for mean field measurements are discussed. A comparison of the two sets of daily observations shows that similar results are obtained at both observatories. A comparison of the mean field with the interplanetary magnetic polarity shows that the IMF sector structure has the same pattern as the mean field polarity.

Comparison of propeller cruise noise data taken in the NASA Lewis 8- by 6-foot wind tunnel with other tunnel and flight data

NASA Technical Reports Server (NTRS)

Dittmar, James H.

1989-01-01

The noise of advanced high speed propeller models measured in the NASA 8- by 6-foot wind tunnel has been compared with model propeller noise measured in another tunnel and with full-scale propeller noise measured in flight. Good agreement was obtained for the noise of a model counterrotation propeller tested in the 8- by 6-foot wind tunnel and in the acoustically treated test section of the Boeing Transonic Wind Tunnel. This good agreement indicates the relative validity of taking cruise noise data on a plate in the 8- by 6-foot wind tunnel compared with the free-field method in the Boeing tunnel. Good agreement was also obtained for both single rotation and counter-rotation model noise comparisons with full-scale propeller noise in flight. The good scale model to full-scale comparisons indicate both the validity of the 8- by 6-foot wind tunnel data and the ability to scale to full size. Boundary layer refraction on the plate provides a limitation to the measurement of forward arc noise in the 8- by 6-foot wind tunnel at the higher harmonics of the blade passing tone. The use of a validated boundary layer refraction model to adjust the data could remove this limitation.

Comparison of propeller cruise noise data taken in the NASA Lewis 8- by 6-foot wind tunnel with other tunnel and flight data

NASA Technical Reports Server (NTRS)

Dittmar, James

1989-01-01

The noise of advanced high speed propeller models measured in the NASA 8- by 6-foot wind tunnel has been compared with model propeller noise measured in another tunnel and with full-scale propeller noise measured in flight. Good agreement was obtained for the noise of a model counterrotation propeller tested in the 8- by 6-foot wind tunnel and in the acoustically treated test section of the Boeing Transonic Wind Tunnel. This good agreement indicates the relative validity of taking cruise noise data on a plate in the 8- by 6-foot wind tunnel compared with the free-field method in the Boeing tunnel. Good agreement was also obtained for both single rotation and counter-rotation model noise comparisons with full-scale propeller noise in flight. The good scale model to full-scale comparisons indicate both the validity of the 8- by 6-foot wind tunnel data and the ability to scale to full size. Boundary layer refraction on the plate provides a limitation to the measurement of forward arc noise in the 8- by 6-foot wind tunnel at the higher harmonics of the blade passing tone. The sue of a validated boundary layer refraction model to adjust the data could remove this limitation.

Applicability of ERTS-1 to Montana geology

NASA Technical Reports Server (NTRS)

Weidman, R. M. (Principal Investigator); Alt, D. D.; Berg, R. A.; Johns, W. M.; Flood, R. E.; Hawley, K. T.; Wackwitz, L. K.

1973-01-01

The author has identified the following significant results. A detailed band 7 ERTS-1 lineament map covering western Montana and northern Idaho has been prepared and is being evaluated by direct comparison with geologic maps, by statistical plots of lineaments and known faults, and by field checking. Lineament patterns apparent in the Idaho and Boulder batholiths do not correspond to any known geologic structures. A band 5 mosaic of Montana and adjacent areas has been laid and a lineament annotation prepared for comparison with the band 7 map. All work to date indicates that ERTS-1 imagery is very useful for revealing patterns of high-angle faults, though much less useful for mapping rock units and patterns of low-angle faults. Large-scale mosaics of U-2 photographs of three test sites have been prepared for annotation and comparison with ERTS-1 maps. Mapping of Quaternary deposits in the Glacial Lake Missoula basin using U-2 color infrared transparencies has been successful resulting in the discovery of some deposits not previously mapped. Detailed work has been done for Test Site 354 D using ERTS-1 imagery; criteria for recognition of several rock types have been found. Photogeologic mapping for southeastern Montana suggest Wasatch deposits where none shown of geologic map.

Habitat management of organic vineyard in Northern Italy: the role of cover plants management on arthropod functional biodiversity.

PubMed

Burgio, G; Marchesini, E; Reggiani, N; Montepaone, G; Schiatti, P; Sommaggio, D

2016-12-01

The effect of cover plants on arthropod functional biodiversity was investigated in a vineyard in Northern Italy, through a 3-year field experiment. The following six ground cover plants were tested: Sweet Alyssum; Phacelia; Buckwheat; Faba Bean; Vetch and Oat; control. Arthropods were sampled using different techniques, including collection of leaves, vacuum sampling and sweeping net. Ground cover plant management significantly affected arthropod fauna, including beneficial groups providing ecosystem services like biological control against pests. Many beneficial groups were attracted by ground cover treatments in comparison with control, showing an aggregative numerical response in the plots managed with some of the selected plant species. Alyssum, Buckwheat and 'Vetch and Oat' mixture showed attractiveness on some Hymenoptera parasitoid families, which represented 72.3% of the insects collected by sweeping net and 45.7 by vacuum sampling. Phytoseiidae mites showed a significant increase on leaves of the vineyard plots managed with ground covers, in comparison with control, although they did not show any difference among the treatments. In general, the tested ground cover treatments did not increase dangerous Homoptera populations in comparison with control, with the exception of Alyssum. The potential of ground cover plant management in Italian vineyards is discussed: the overall lack of potential negative effects of the plants tested, combined with an aggregative numerical response for many beneficials, seems to show a potential for their use in Northern Italy vineyards.

Field Verification Program (Aquatic Disposal): Comparison of Field and Laboratory Bioaccumulation of Organic and Inorganic Contaminants from Black Rock Harbor Dredged Material

DTIC Science & Technology

1988-05-01

include poly- chlorinated biphenyls (PCBs) and related chlorinated pesticides of similar polarity in addition to the petroleum hydrocarbons . The...Ui It tILL (JV: FIELD VERIFICATION PROGRAM (AQUATIC DISPOSAL).’Wh TECHNICAL REPORT D-87-6 COMPARISON OF FIELD AND LABORATORY BIOACCUMULATION OF...Laboratory Bioaccumulation of Organic and Inorganic Contaminants from Black Rock Harbor Dredged Material 12 PERSONAL AUTHOR(S) Lake, James L.; Galloway

Numerical simulation of photocurrent generation in bilayer organic solar cells: Comparison of master equation and kinetic Monte Carlo approaches

NASA Astrophysics Data System (ADS)

Casalegno, Mosè; Bernardi, Andrea; Raos, Guido

2013-07-01

Numerical approaches can provide useful information about the microscopic processes underlying photocurrent generation in organic solar cells (OSCs). Among them, the Kinetic Monte Carlo (KMC) method is conceptually the simplest, but computationally the most intensive. A less demanding alternative is potentially represented by so-called Master Equation (ME) approaches, where the equations describing particle dynamics rely on the mean-field approximation and their solution is attained numerically, rather than stochastically. The description of charge separation dynamics, the treatment of electrostatic interactions and numerical stability are some of the key issues which have prevented the application of these methods to OSC modelling, despite of their successes in the study of charge transport in disordered system. Here we describe a three-dimensional ME approach to photocurrent generation in OSCs which attempts to deal with these issues. The reliability of the proposed method is tested against reference KMC simulations on bilayer heterojunction solar cells. Comparison of the current-voltage curves shows that the model well approximates the exact result for most devices. The largest deviations in current densities are mainly due to the adoption of the mean-field approximation for electrostatic interactions. The presence of deep traps, in devices characterized by strong energy disorder, may also affect result quality. Comparison of the simulation times reveals that the ME algorithm runs, on the average, one order of magnitude faster than KMC.

CFD Modeling of Flow, Temperature, and Concentration Fields in a Pilot-Scale Rotary Hearth Furnace

NASA Astrophysics Data System (ADS)

Liu, Ying; Su, Fu-Yong; Wen, Zhi; Li, Zhi; Yong, Hai-Quan; Feng, Xiao-Hong

2014-01-01

A three-dimensional mathematical model for simulation of flow, temperature, and concentration fields in a pilot-scale rotary hearth furnace (RHF) has been developed using a commercial computational fluid dynamics software, FLUENT. The layer of composite pellets under the hearth is assumed to be a porous media layer with CO source and energy sink calculated by an independent mathematical model. User-defined functions are developed and linked to FLUENT to process the reduction process of the layer of composite pellets. The standard k-ɛ turbulence model in combination with standard wall functions is used for modeling of gas flow. Turbulence-chemistry interaction is taken into account through the eddy-dissipation model. The discrete ordinates model is used for modeling of radiative heat transfer. A comparison is made between the predictions of the present model and the data from a test of the pilot-scale RHF, and a reasonable agreement is found. Finally, flow field, temperature, and CO concentration fields in the furnace are investigated by the model.

A method for the estimate of the wall diffusion for non-axisymmetric fields using rotating external fields

NASA Astrophysics Data System (ADS)

Frassinetti, L.; Olofsson, K. E. J.; Fridström, R.; Setiadi, A. C.; Brunsell, P. R.; Volpe, F. A.; Drake, J.

2013-08-01

A new method for the estimate of the wall diffusion time of non-axisymmetric fields is developed. The method based on rotating external fields and on the measurement of the wall frequency response is developed and tested in EXTRAP T2R. The method allows the experimental estimate of the wall diffusion time for each Fourier harmonic and the estimate of the wall diffusion toroidal asymmetries. The method intrinsically considers the effects of three-dimensional structures and of the shell gaps. Far from the gaps, experimental results are in good agreement with the diffusion time estimated with a simple cylindrical model that assumes a homogeneous wall. The method is also applied with non-standard configurations of the coil array, in order to mimic tokamak-relevant settings with a partial wall coverage and active coils of large toroidal extent. The comparison with the full coverage results shows good agreement if the effects of the relevant sidebands are considered.

Comparison of Mixing Calculations for Reacting and Non-Reacting Flows in a Cylindrical Duct

NASA Technical Reports Server (NTRS)

Oechsle, V. L.; Mongia, H. C.; Holdeman, J. D.

1994-01-01

A production 3-D elliptic flow code has been used to calculate non-reacting and reacting flow fields in an experimental mixing section relevant to a rich burn/quick mix/lean burn (RQL) combustion system. A number of test cases have been run to assess the effects of the variation in the number of orifices, mass flow ratio, and rich-zone equivalence ratio on the flow field and mixing rates. The calculated normalized temperature profiles for the non-reacting flow field agree qualitatively well with the normalized conserved variable isopleths for the reacting flow field indicating that non-reacting mixing experiments are appropriate for screening and ranking potential rapid mixing concepts. For a given set of jet momentum-flux ratio, mass flow ratio, and density ratio (J, MR, and DR), the reacting flow calculations show a reduced level of mixing compared to the non-reacting cases. In addition, the rich-zone equivalence ratio has noticeable effect on the mixing flow characteristics for reacting flows.