138 research outputs found

    A self-study course in FORTRAN programming. Volume 1 - Textbook

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    Self study textbook for course in FORTRAN programming - Vol.

    A self-study course in FORTRAN programming. Volume 2 - Workbook

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    Self study workbook for course in FORTRAN programming - Vol.

    Investigating Use of Aggregate Density to Develop Design Aggregate Structure for Asphalt Concrete Mixtures

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    In recent years there have been several instances of premature failures of pavements in West Virginia due to rutting. While there are various potential causes for the failures, aggregate density within the mix when designed at 80 gyrations was of specific concern to this thesis and was compared to the maximum dry density of the aggregate as measured using ASTM D4253-00. The objective of this research was to determine if the aggregate in the asphalt concrete mixture was reaching a dense configuration.;The Bailey Method was used to choose gradations and the selected research methodology supported the evaluation of the Bailey Method as a means for estimating changes in mix volumetric properties with changes to aggregate gradation. Aggregate density at various locking point definitions, as well as, N des and Nmax of 80 and 125 gyrations respectively, were evaluated to assess the effects of compacting to current Ndes level versus locking point.;Statistical methods were used to analyze the various test results including, line of equality charts and t-tests to test for equality. All results were evaluated at a 95% confidence level for consistency. It was determined that the aggregates in the asphalt concrete specimens achieved a dense aggregate structure when compacted to 80 gyrations when compared to the dry density specimens. Also, as the CA ratio increases the IDT strength increases indicating more resistance to rutting in the field. This could be a useful tool in choosing a gradation as the CA ratio can be determined from the gradation

    FORTRAN programming - A self-taught course

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    Comprehensive programming course begins with numerical systems and basic concepts, proceeds systematically through FORTRAN language elements, and concludes with discussion of programming techniques. Course is suitable either for individual study or for group study on informal basis

    Field Scanner Design for MUSTANG of the Green Bank Telescope

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    MUSTANG is a bolometer camera for the Green Bank Telescope (GBT) working at a frequency of 90 GHz. The detector has a field of view of 40 arcseconds. To cancel out random emission change from atmosphere and other sources, requires a fast scanning reflecting system with a few arcminute ranges. In this paper, the aberrations of an off-axis system are reviewed. The condition for an optimized system is provided. In an optimized system, as additional image transfer mirrors are introduced, new aberrations of the off-axis system may be reintroduced, resulting in a limited field of view. In this paper, different scanning mirror arrangements for the GBT system are analyzed through the ray tracing analysis. These include using the subreflector as the scanning mirror, chopping a flat mirror and transferring image with an ellipse mirror, and chopping a flat mirror and transferring image with a pair of face-to-face paraboloid mirrors. The system analysis shows that chopping a flat mirror and using a well aligned pair of paraboloids can generate the required field of view for the MUSTUNG detector system, while other systems all suffer from larger off-axis aberrations added by the system modification. The spot diagrams of the well aligned pair of paraboloids produced is only about one Airy disk size within a scanning angle of about 3 arcmin.Comment: 7 pages, 9 figure

    Phased Array Feed Calibration, Beamforming and Imaging

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    Phased array feeds (PAFs) for reflector antennas offer the potential for increased reflector field of view and faster survey speeds. To address some of the development challenges that remain for scientifically useful PAFs, including calibration and beamforming algorithms, sensitivity optimization, and demonstration of wide field of view imaging, we report experimental results from a 19 element room temperature L-band PAF mounted on the Green Bank 20-Meter Telescope. Formed beams achieved an aperture efficiency of 69% and system noise temperature of 66 K. Radio camera images of several sky regions are presented. We investigate the noise performance and sensitivity of the system as a function of elevation angle with statistically optimal beamforming and demonstrate cancelation of radio frequency interference sources with adaptive spatial filtering.Comment: 19 pages, 13 figure

    Chemically bound gold nanoparticle arrays on silicon: assembly, properties and SERS study of protein interactions

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    A highly reproducible and facile method for formation of ordered 2 dimensional arrays of CTAB protected 50 nm gold nanoparticles bonded to silicon wafers is described. The silicon wafers have been chemically modified with long-chain silanes terminated with thiol that penetrate the CTAB bilayer and chemically bind to the underlying gold nanoparticle. The silicon wafer provides a reproducibly smooth, chemically functionalizable and non-fluorescent substrate with a silicon phonon mode which may provide a convenient internal frequency and intensity calibration for vibrational spectroscopy. The CTAB bilayer provides a potentially biomimetic environment for analyte, yet allows a sufficiently small nanoparticle separation to achieve a significant electric field enhancement. The arrays have been characterized using SEM and Raman spectroscopy. These studies reveal that the reproducibility of the arrays is excellent both between batches (< 10% RSD) and across a single batch (< 5% RSD). The arrays also exhibit good stability, and the effect of temperature on the arrays was also investigated. The interaction of protein and amino acid with the nanoparticle arrays was investigated using Raman microscopy to investigate their potential in bio-SERS spectroscopy. Raman of phenylalanine and the protein bovine pancreatic trypsin inhibitor, BPTI were studied using 785 nm excitation, coincident with the surface plasmon absorbance of the array. The arrays exhibit SERS enhancements of the order of 2.6 x 104 for phenylalanine, the standard deviation on the relative intensity of the 1555 cm-1 mode of phenylalanine is less than 10% for 100 randomly distributed locations across a single substrate and less than 20% between different substrates. Significantly, comparisons of the Raman spectra of the protein and phenlyalanine in solution and immobilized on the nanoparticle arrays indicates that the protein is non-randomly orientated on the arrays. Selective SERS enhancements suggest that aromatic residues penetrate through the bilayer inducing conformational changes in the protein

    An address delivered at Asbury Theological Seminary chapel service, (2009, March 11)

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    https://place.asburyseminary.edu/ecommonsatschapelservices/6266/thumbnail.jp
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