1,268 research outputs found
Prediction of Acoustical Response of Three-dimensional Cavities Using an Indirect Boundary Element Method
A technique which characterizes the acoustics of generalized cavities with the minimum model possible is developed. All boundary element methods have two advantages over finite element methods: (1) the models are smaller; and (2) the assumed variable behavior, inherent in the method to allow discretization, is harmonic rather than polynomial. Further, IBEM often requires one rather than two numerical boundary integrals as required by DBEM. Thus, a quadratic, isoparametric IBEM program was developed. The source distribution in this solution is continuous and quadratically variable rather than continuous and constant. The program was also formulated to include the additional capability of interior point sources and impedance boundary conditions. To test the quadratic, isoparametric IBEM program, several simple cavity enclosure problems where studied. Results are shown
The GEOTRACES Intermediate Data Product 2017
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at crossover stations. The IDP2017 consists of two parts: (1) a compilation of digital data for more than 450 TEIs as well as standard hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing an on-line atlas that includes more than 590 section plots and 130 animated 3D scenes. The digital data are provided in several formats, including ASCII, Excel spreadsheet, netCDF, and Ocean Data View collection. Users can download the full data packages or make their own custom selections with a new on-line data extraction service. In addition to the actual data values, the IDP2017 also contains data quality flags and 1-σ data error values where available. Quality flags and error values are useful for data filtering and for statistical analysis. Metadata about data originators, analytical methods and original publications related to the data are linked in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2017 as section plots and rotating 3D scenes. The basin-wide 3D scenes combine data from many cruises and provide quick overviews of large-scale tracer distributions. These 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of tracer plumes near ocean margins or along ridges. The IDP2017 is the result of a truly international effort involving 326 researchers from 25 countries. This publication provides the critical reference for unpublished data, as well as for studies that make use of a large cross-section of data from the IDP2017
Crop-phenology and LANDSAT-based irrigated lands inventory in the high plains
Optimal LANDSAT image dates for 1980 were identified based on the weekly crop-weather reports for Colorado, New Mexico, South Dakota, Texas, Oklahoma, Kansas, Nebraska, and Wyoming. The 1979 agricultural statistics data were entered into computer files and a revised questionnaire was developed and mailed to ASCS county agents. A set of computer programs was developed to allow the preparation of computer-assisted graphic displays of much of the collected data
Crop phenology and LANDSAT-based irrigated lands inventory in the high plains
The activity concentrated on identifying crop and irrigation data sources for the eight states within the High Plains Aquifer and making contacts concerning the nature of these data. A mail questionnaire was developed to gather specific data not routinely reported through standard data collection channels. Input/output routines were designed for High Plains crop and irrigation data and initial statistical data on crops were input to computer files
Aerothermodynamic Assessment of Corrugated Panel Thermal Protection Systems
The feasibility of using corrugated panels as a thermal protection system for an advanced space transportation vehicle was investigated. The study consisted of two major tasks: development of improved correlations for wind tunnel heat transfer and pressure data to yield design techniques, and application of the design techniques to determine if corrugated panels have application future aerospace vehicles. A single-stage-to-orbit vehicle was used to assess advantages and aerothermodynamic penalties associated with use of such panels. In the correlation task, experimental turbulent heat transfer and pressure data obtained on corrugation roughened surfaces during wind tunnel testing were analyzed and compared with flat plate data. The correlations and data comparisons included the effects of a large range of geometric, inviscid flow, internal boundary layer, and bulk boundary layer parameters in supersonic and hypersonic flow
Legislatively Directed Judicial Activism: Some Reflections on the Meaning of the Civil Justice Reform Act
With the Civil Justice Reform Act (CJRA), Congress attempted to further a trend that the federal judiciary had undertaken largely on its own initiative. Sensing a critical need to address the mounting expense and delay of federal civil litigation, Congress, like the judiciary, sought to increase the degree of early and active involvement of judges in the adjudicatory process. The result of this mandate has been a further emphasis on the role of the judge as a case manager. As a necessary corollary, the liberty and self-determination of individual litigants-ideals that have historically been seen as philosophical cornerstones of the Anglo-American adjudicative process-have been correspondingly diminished. In this Article, the authors examine the departure from the philosophical moorings of the Anglo-American system of justice that implementation of the CJRA represents and consider whether the gains to be achieved by the Act, if successful, offset the potential costs to the litigants that the Act imposes
Legislatively Directed Judicial Activism: Some Reflections on the Meaning of the Civil Justice Reform Act, 28 U. Mich. J.L. Reform 305 (1995)
With the Civil Justice Reform Act (CJRA), Congress attempted to further a trend that the federal judiciary had undertaken largely on its own initiative. Sensing a critical need to address the mounting expense and delay of federal civil litigation, Congress, like the judiciary, sought to increase the degree of early and active involvement of judges in the adjudicatory process. The result of this mandate has been a further emphasis on the role of the judge as a case manager. As a necessary corollary, the liberty and self-determination of individual litigants-ideals that have historically been seen as philosophical cornerstones of the Anglo-American adjudicative process-have been correspondingly diminished. In this Article, the authors examine the departure from the philosophical moorings of the Anglo-American system of justice that implementation of the CJRA represents and consider whether the gains to be achieved by the Act, if successful, offset the potential costs to the litigants that the Act imposes
Modeling pN2 through Geological Time: Implications for Planetary Climates and Atmospheric Biosignatures
Nitrogen is a major nutrient for all life on Earth and could plausibly play a
similar role in extraterrestrial biospheres. The major reservoir of nitrogen at
Earth's surface is atmospheric N2, but recent studies have proposed that the
size of this reservoir may have fluctuated significantly over the course of
Earth's history with particularly low levels in the Neoarchean - presumably as
a result of biological activity. We used a biogeochemical box model to test
which conditions are necessary to cause large swings in atmospheric N2
pressure. Parameters for our model are constrained by observations of modern
Earth and reconstructions of biomass burial and oxidative weathering in deep
time. A 1-D climate model was used to model potential effects on atmospheric
climate. In a second set of tests, we perturbed our box model to investigate
which parameters have the greatest impact on the evolution of atmospheric pN2
and consider possible implications for nitrogen cycling on other planets. Our
results suggest that (a) a high rate of biomass burial would have been needed
in the Archean to draw down atmospheric pN2 to less than half modern levels,
(b) the resulting effect on temperature could probably have been compensated by
increasing solar luminosity and a mild increase in pCO2, and (c) atmospheric
oxygenation could have initiated a stepwise pN2 rebound through oxidative
weathering. In general, life appears to be necessary for significant
atmospheric pN2 swings on Earth-like planets. Our results further support the
idea that an exoplanetary atmosphere rich in both N2 and O2 is a signature of
an oxygen-producing biosphere.Comment: 33 pages, 11 figures, 2 tables (includes appendix), published in
Astrobiolog
PRINCIPAL COMPONENT ANALYSIS OF FREE THROW SHOT TRAJECTORIES IN RELATION TO SHOOTING PERFORMANCE
The purpose of this study was to analyze free throw (FT) shot trajectories of individual basketball players using principal component analysis (PCA) and investigate whether variation in trajectories correlated with FT shooting performance. A markerless motion capture system was used to record three-dimensional FT shot trajectories of seven basketball players during practice. Horizontal and vertical positioning of the wrist joint center of the shooting hand were captured in both the sagittal and frontal planes for all trials. These coordinates were used as the input to the PCA. Positive correlations between the amount of variation accounted for by the first principal component and FT shooting performance (in-game FT%) suggest that players with simpler and less variable (i.e., more deterministic) shooting trajectories are better FT shooters
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