28,970 research outputs found
Study of convective magnetohydrodynamic channel flow
Study involves the effects of the interactions of electromagnetic, velocity, and temperature fields to aid in the design of a magnetohydrodynamic device. It concerns a theoretical analysis of the convective flow of an electrically conducting gas in a channel composed of conducting walls
Visible and near-IR spectral reflectance of geologically important materials: A short review
Examples of reflectance spectra are presented and discussed for various mineral groups including pyroxenes, olivene, phylosilicates, amphiboles, feldspars, oxides and hydroxides, carbonates, and mixtures of minerals. The physical sources of some spectral features are also reviewed such as charge transfer and conduction bands, crystal field absorptions, and vibrational absorptions
A next-generation mapping spectrometer
Operational and design characteristics for a remote sensing instrument for aircraft and orbital use are defined. The ideal instrument would be based around two-dimensional detector arrays, silicon for the visible and very-near infrared (0.4 to 1.0 microns) and InSb or PbS for the rest of the near-infrared (out to about 2.6 microns). Spectral information would be dispersed along one axis. Thus one exposure or frame would simultaneously record a full spectrum for each pixel in a row perpendicular to the ground track. The instrument should be smart and versatile, with extensive pre-processing capability programmable from the ground. Spatial and spectral resolution, signal to noise radio, data precision, and calibration and atmospheric corrections are also discussed
Evaluating Lossy Collections for Java Applications
We propose to remove live objects from near-full heaps to
reduce memory pressure. We modify Java Collections to
enable lossy behavior. Some DaCapo benchmarks tolerate
an amount of live data loss
Rapid Bayesian position reconstruction for gravitational-wave transients
Within the next few years, Advanced LIGO and Virgo should detect
gravitational waves from binary neutron star and neutron star-black hole
mergers. These sources are also predicted to power a broad array of
electromagnetic transients. Because the electromagnetic signatures can be faint
and fade rapidly, observing them hinges on rapidly inferring the sky location
from the gravitational-wave observations. Markov chain Monte Carlo methods for
gravitational-wave parameter estimation can take hours or more. We introduce
BAYESTAR, a rapid, Bayesian, non-Markov chain Monte Carlo sky localization
algorithm that takes just seconds to produce probability sky maps that are
comparable in accuracy to the full analysis. Prompt localizations from BAYESTAR
will make it possible to search electromagnetic counterparts of compact binary
mergers.Comment: 23 pages, 12 figures, published in Phys. Rev.
Radiation Damping Effects in Two Level Maser Oscillators
Several experiments [1,2] have noted recently that when an inverted two-level spin system was permitted to radiate spontaneously, the resulting oscillation was characterized by an appreciable amplitude modulation. The phenomenon was first believed to be the result of interference of different spin packets in an inhomogeneously broadened spectrum [1]. A theoretical analysis (which will be reported separately) shows that this is not the case. The spins are not independent but are coupled together by means of their radiation field. This explanation has since been by its original authors
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