28,318 research outputs found
Switching circuit Patent
Solid state circuit for switching alternating current input signal as function of direct current gating transisto
A low-power photovoltaic system with energy storage for radio communications: Description and design methodology
A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort
Sub-mm counterparts to Lyman-break galaxies
We summarize the main results from our SCUBA survey of Lyman-break galaxies
(LBGs) at z~3. Analysis of our sample of LBGs reveals a mean flux of
S850=0.60.2 mJy, while simple models of emission based on the UV
properties predict a mean flux about twice as large. Known populations of LBGs
are expected to contribute flux to the weak sub-mm source portion of the far-IR
background, but are not likely to comprise the bright source (S850>5 mJy) end
of the SCUBA-detected source count. The detection of the LBG, Westphal-MM8, at
1.9 mJy suggests that deeper observations of individual LBGs in our sample
could uncover detections at similar levels, consistent with our UV-based
predictions. By the same token, many sub-mm selected sources with S850<2 mJy
could be LBGs. The data are also consistent with the FarIR/ relation
holding at z=3.Comment: 6 pages, 1 figure, contributed talk at UMass/INAOE Conference ``Deep
Millimeter Surveys'
Single-stage experimental evaluation of boundary layer bleed techniques for high lift stator blades. Compressors design
Design and evaluation of stator blades for use in boundary layer bleed techniques in axial flow compresso
Single-stage experimental evaluation of boundary layer blowing techniques for high lift stator blades. 1 - Compressor design
Boundary layer blowing techniques for high lift stator blades in axial flow compressor
From the Boltzmann equation to fluid mechanics on a manifold
We apply the Chapman-Enskog procedure to derive hydrodynamic equations on an
arbitrary surface from the Boltzmann equation on the surface
Detailed Structure and Dynamics in Particle-in-Cell Simulations of the Lunar Wake
The solar wind plasma from the Sun interacts with the Moon, generating a wake
structure behind it, since the Moon is to a good approximation an insulator,
has no intrinsic magnetic field and a very thin atmosphere. The lunar wake in
simplified geometry has been simulated via a 1-1/2-D electromagnetic
particle-in-cell code, with high resolution in order to resolve the full phase
space dynamics of both electrons and ions. The simulation begins immediately
downstream of the moon, before the solar wind has infilled the wake region,
then evolves in the solar wind rest frame. An ambipolar electric field and a
potential well are generated by the electrons, which subsequently create a
counter-streaming beam distribution, causing a two-stream instability which
confines the electrons. This also creates a number of electron phase space
holes. Ion beams are accelerated into the wake by the ambipolar electric field,
generating a two stream distribution with phase space mixing that is strongly
influenced by the potentials created by the electron two-stream instability.
The simulations compare favourably with WIND observations.Comment: 10 pages, 13 figures, to be published in Physics of Plasma
Data base on physical observations of near-Earth asteroids and establishment of a network to coordinate observations of newly discovered near-Earth asteroids
This program consists of two tasks: (1) development of a data base of physical observations of near-earth asteroids and establishment of a network to coordinate observations of newly discovered earth-approaching asteroids; and (2) a simulation of the surface of low-activity comets. Significant progress was made on task one and, and task two was completed during the period covered by this progress report
High temperature glass coatings for superalloys and refractory metals
New glasses are used as protective coatings on metals and alloys susceptible to oxidation at high temperatures in oxidizing atmospheres. Glasses are stable and solid at temperatures up to 1000 deg C, adhere well to metal surfaces, and are usable for metals with broad range of expansion coefficients
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