24,973 research outputs found

    Impartial Evaluations of the Printing Quality of Paper

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    Several methods for the evaluation of paper have been investigated for their desirability as means of an impartial evaluation of the printing quality of paper. The halftone plate method showed the most desired results as an impartial evaluation of both coated and uncoated papers. The printing gage was not found to be a satisfactory method of evaluation. The drawdown method is especially significant in evaluating properties which influence the printing quality but lacks a suitable numerical evaluation

    Jarzynski equation for a simple quantum system: Comparing two definitions of work

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    The validity of the Jarzynski equation for a very simple, exactly solvable quantum system is analyzed. The implications of two different definitions of work proposed in the literature are investigated. The first one derives from measurements of the system energy at the beginning and at the end of the process under consideration making the work a classical stochastic variable with transition probabilities derived from quantum mechanics. In the second definition an operator of work is introduced and the average in the Jarzynski equation is a quantum expectation value. For the first definition a general quantum mechanical version of the Jarzynski equation is known to hold. For the second one the Jarzynski equation fails to yield the free energy difference at low temperature.Comment: 5 papes, 1 figure largly rewritten and slightly enlarged versio

    On the electromagnetic force on a polarizable body

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    The force on a macroscopic polarizable body in an inhomogenous electromagnetic field is calculated for three simple exactly solvable situations. Comparing different approaches we pinpoint possible pitfalls and resolve recent confusion about the force density in ferrofluids.Comment: 8 pages, 3 figures, submitted to Am. J. Phy

    Digital data reformatter/deserializer

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    A method and apparatus is presented for reformatting and de-serializing a serially-received sequence of data words, each consisting of a fixed number of binary data bits. A block of nm bits is serially fed into a shift register or serially-connected group of shift registers. In lieu of the(nm-1)th shifts, the bits are rearranged within the shift register in parallel fashion, according to a prescribed scheme. Shifting then continues, until the first bit of each data word appears in the last bit position in the shift register, at which time that data word is shifted in parallel into an output buffer stage, from which it is outputted in parallel, after a fixed delay

    Impact of Uncertainties in Hadron Production on Air-Shower Predictions

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    At high energy, cosmic rays can only be studied by measuring the extensive air showers they produce in the atmosphere of the Earth. Although the main features of air showers can be understood within a simple model of successive interactions, detailed simulations and a realistic description of particle production are needed to calculate observables relevant to air shower experiments. Currently hadronic interaction models are the main source of uncertainty of such simulations. We will study the effect of using different hadronic models available in CORSIKA and CONEX on extensive air shower predictions.Comment: 12 pages, 6 figures, to appear in the proceedings of International Conference on Interconnection between High Energy Physics and Astroparticle Physics: From Colliders to Cosmic Rays, Prague, Czech Republic, 7-13 Sep 200

    Geosynchrotron radio emission from CORSIKA-simulated air showers

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    Simulations of radio emission from extensive air showers we have published so far were performed with a Monte Carlo code using analytical parametrisations to describe the spatial, temporal, energy and angular particle distributions in the air shower. A new version of our simulation code, which replaces these parametrisations with precise, multi-dimensional histograms derived from per-shower CORSIKA simulations, is now available. The new code allows an independent selection between parametrisation and histogram for each of the relevant distributions, enabling us to study the changes arising from using a more realistic air shower model in detail. We describe the new simulation strategy, present some initial results and discuss the new possibilities.Comment: 6 pages, Proceedings of the ARENA2006 workshop, Newcastle, England; to be published in Journal of Physics: Conference Series (JPCS

    Mojave Applied Ecology Notes Summer 2010

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    Survey of monitoring and management for conservation of rare plants, Roadside restoration techniques in Joshua Tree NP, and an update on renewable energy developments in the Southwestern desert
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