477 research outputs found

    SPHERES, J\"ulich's High-Flux Neutron Backscattering Spectrometer at FRM II

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    SPHERES (SPectrometer with High Energy RESolution) is a third-generation neutron backscattering spectrometer, located at the 20 MW German neutron source FRM II and operated by the Juelich Centre for Neutron Science. It offers an energy resolution (fwhm) better than 0.65 micro-eV, a dynamic range of +-31 micro-eV, and a signal-to-noise ratio of up to 1750:1.Comment: 12 pages, 7 figures, 2 tables. Supplemental material consists of 3 pages, 2 figures, 2 table

    Analysis of dynamic behavior of the back-toback High Voltage Direct Current link model as part of electrical power system

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    One of the main directions of the development of electric power systems is the introduction of technologies based on high-power semiconductor switches, such as FACTS devices and HVDC technologies. These systems effectively solve a number of urgent tasks of EPS, connected with asynchronous connection of EPS, transmission of electricity, improve local and systemic flexibility and reliability of EPS, increasing the capacity of network elements that contains a "weak" connection. However, the implementation and operation of mentioned technologies in the EPS determines the need for a wide range of analysis and research that can only be done with the help of mathematical modeling

    Honors Project- Goodyear

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    The Goodyear Tire and Rubber Company is investigating whether or not their soybean oil tires should be advertised as such to the public. This paper discusses the various research methods that were used to come up with reccomendations to Goodyear. Some of these methods include secondary search, store observations, a survey, and a focus group. With the recommendations outlined in the paper, The Goodyear Tire and Rubber Company can assure great success with their soybean oil tires

    On the Mixed Gas Behavior of Organosilica Membranes Fabricated by Plasma-Enhanced Chemical Vapor Deposition (PECVD)

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    Selective, nanometer-thin organosilica layers created by plasma-enhanced chemical vapor deposition (PECVD) exhibit selective gas permeation behavior. Despite their promising pure gas performance, published data with regard to mixed gas behavior are still severely lacking. This study endeavors to close this gap by investigating the pure and mixed gas behavior depending on temperatures from 0 °C to 60 °C for four gases (helium, methane, carbon dioxide, and nitrogen) and water vapor. For the two permanent gases, helium and methane, the studied organosilica membrane shows a substantial increase in selectivity from αHe/CH4 = 9 at 0 °C to αHe/CH4 = 40 at 60 °C for pure as well as mixed gases with helium permeance of up to 300 GPU. In contrast, a condensable gas such as CO2 leads to a decrease in selectivity and an increase in permeance compared to its pure gas performance. When water vapor is present in the feed gas, the organosilica membrane shows even stronger deviations from pure gas behavior with a permeance loss of about 60 % accompanied by an increase in ideal selectivity αHe/CO2 from 8 to 13. All in all, the studied organosilica membrane shows very promising results for mixed gases. Especially for elevated temperatures, there is a high potential for separation by size exclusion

    Formation and investigation of micro-arc Sr-containing calciumphosphate biocoatings on Mg-0.8 Ca alloy

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    The investigation of the XRD analysis, thickness, masses and roughness of Sr-substituted calcium phosphate coatings on the Mg-0.8Ca substrate deposited by the micro arc oxidation method under different process voltages was performed. The increase of the process voltage leads to the growth of the thickness, masses and roughness of the coatings. Results of XRD analysis showed that the Sr-CaP coatings formed under the process voltages of 350-450 V are contained α-Ca[3](PO[4])[2], Mg[3](PO[4])[2] and Mg phases

    The Polarized H and D Atomic Beam Source for ANKE at COSY-J\"ulich

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    A polarized atomic beam source was developed for the polarized internal storage-cell gas target at the magnet spectrometer ANKE of COSY-J\"ulich. The intensities of the beams injected into the storage cell, measured with a compression tube, are 7.510167.5\cdot 10^{16} hydrogen atoms/s (two hyperfine states) and 3.910163.9\cdot 10^{16} deuterium atoms/s (three hyperfine states). For the hydrogen beam the achieved vector polarizations are pz±0.92p_{\rm z}\approx\pm0.92. For the deuterium beam, the obtained combinations of vector and tensor (pzzp_{\rm zz}) polarizations are pz±0.90p_{\rm z}\approx\pm 0.90 (with a constant pzz+0.86p_{\rm zz}\approx +0.86), and pzz=+0.90p_{\rm zz}=+0.90 or pzz=1.71p_{\rm zz}=-1.71 (both with vanishing pzp_{\rm z}). The paper includes a detailed technical description of the apparatus and of the investigations performed during the development.Comment: 18 pages, 26 figures, 4 table

    WU Polyomavirus (WUPyV): A Recently Detected Virus Causing Respiratory Disease?

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    The WU polyomavirus (WUPyV) is a novel member of the family Polyomaviridae recently detected in respiratory tract specimens by shotgun sequencing. Intriguingly, viral genome has been detected in 0.4% to 11.5% of respiratory tract specimens from children with respiratory disease. The levels of co-infection with established respiratory viruses were in the range between 30.8% and 91.7%. Moreover, some studies report detection of WUPyV in stool or serum. So far, WUPyV infections can not be distinguished from other viral infections by means of clinical symptoms. Respiratory tract disease like pneumonia or bronchitis is frequently observed in patients harbouring WUPyV. Detection of viremia suggests systemic infections. However, the available data do not prove WUPyV to be a human pathogen. Further investigations are necessary
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