25,241 research outputs found
Impartial Evaluations of the Printing Quality of Paper
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
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
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
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
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
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
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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