34,297 research outputs found

    Cost and size estimates for an electrochemical bulk energy storage concept

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    Preliminary capital cost and size estimates were made for an electrochemical bulk energy storage concept. The electrochemical system considered was an electrically rechargeable flow cell with a redox couple. On the basis of preliminary capital cost estimates, size estimates, and several other important considerations, the redox-flow-cell system emerges as having great promise as a bulk energy storage system for power load leveling. The size of this system would be less than 2 percent of that of a comparable pumped hydroelectric plant. The capital cost of a 10-megawatt, 60- and 85-megawatt-hour redox system is estimated to be 190to190 to 330 per kilowatt. The other important features of the redox system contributing to its load leveling application are its low adverse environmental impact, its high efficiency, its apparent absence of electrochemically-related cycle life limitations, and its fast response

    DETERMINANTS OF CONSUMER ATTITUDES AND PURCHASE INTENTIONS WITH REGARD TO GM FOODS

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    Consumer acceptance of genetically modified (GM) products has become a vital factor in determining how prosperous the markets for GM products will be in the future. This phenomenon creates increased interest in understanding consumer attitudes and purchase intentions with regard to GM foods. Thus, this paper presents results based on a contingent valuation questionnaire designed to assess consumer knowledge, awareness and willingness to purchase GM-tomatoes in Huntsville metropolitan area, Alabama. The results suggest that attitudes and purchase decisions concerning GM foods are generally negative, highly complex and are based on several factors.Consumer/Household Economics,

    Picosecond time scale imaging of mechanical contacts

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    By means of an ultrafast opto-acoustic technique we study the nanoindentation of thin chromium films on sapphire substrates using a ceramic ball bearing. Acoustic pulses at 40 GHz returning from the film–indenter interface allow the film indentation profiles to be probed to sub-nanometer resolution over contact areas 25 lm in radius. The deformation of the films during loading is hereby revealed. Furthermore, thermal wave imaging of the contact at megahertz frequencies is simultaneously achieved

    Orbital calculations and trapped radiation mapping

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    Flux and energy spectra code for orbital calculations and trapped radiation mappin

    Observations of apparent superslow wave propagation in solar prominences

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    Phase mixing of standing continuum Alfv\'en waves and/or continuum slow waves in atmospheric magnetic structures such as coronal arcades can create the apparent effect of a wave propagating across the magnetic field. We observe a prominence with SDO/AIA on 2015 March 15 and find the presence of oscillatory motion. We aim to demonstrate that interpreting this motion as a magneto hydrodynamic (MHD) wave is faulty. We also connect the decrease of the apparent velocity over time with the phase mixing process, which depends on the curvature of the magnetic field lines. By measuring the displacement of the prominence at different heights to calculate the apparent velocity, we show that the propagation slows down over time, in accordance with the theoretical work of Kaneko et al. We also show that this propagation speed drops below what is to be expected for even slow MHD waves for those circumstances. We use a modified Kippenhahn-Schl\"uter prominence model to calculate the curvature of the magnetic field and fit our observations accordingly. Measuring three of the apparent waves, we get apparent velocities of 14, 8, and 4 km/s. Fitting a simple model for the magnetic field configuration, we obtain that the filament is located 103 Mm below the magnetic centre. We also obtain that the scale of the magnetic field strength in the vertical direction plays no role in the concept of apparent superslow waves and that the moment of excitation of the waves happened roughly one oscillation period before the end of the eruption that excited the oscillation. Some of the observed phase velocities are lower than expected for slow modes for the circumstances, showing that they rather fit with the concept of apparent superslow propagation. A fit with our magnetic field model allows for inferring the magnetic geometry of the prominence.Comment: 10 pages, 6 figures, 1 of which consists of 3 panel

    Combustion instability prediction using a nonlinear bipropellant vaporization model

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    Combustion instability prediction using nonlinear bipropellant vaporization mode
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