23,121 research outputs found
Solid-state configurations
Two prototype solid-state phased array systems concepts developed for the solar power satellite (SPS) are described. In both concepts, the beam was centered on the rectenna by means of phase conjugation of a pilot signal emanating from the ground. Also discussed are results of solid state studies
Mobile Bay turbidity study
The termination of studies carried on for almost three years in the Mobile Bay area and adjacent continental shelf are reported. The initial results concentrating on the shelf and lower bay were presented in the interim report. The continued scope of work was designed to attempt a refinement of the mathematical model, assess the effectiveness of optical measurement of suspended particulate material and disseminate the acquired information. The optical characteristics of particulate solutions are affected by density gradients within the medium, density of the suspended particles, particle size, particle shape, particle quality, albedo, and the angle of refracted light. Several of these are discussed in detail
Creep at Elevated Temperatures and High Vacuum
High vacuum, high temperature, creep tests on copper and silve
The dynamic analysis of submerged structures
Methods are described by which the dynamic interaction of structures with surrounding fluids can be computed by using finite element techniques. In all cases, the fluid is assumed to behave as an acoustic medium and is initially stationary. Such problems are solved either by explicitly modeling the fluid (using pressure or displacement as the basic fluid unknown) or by using decoupling approximations which take account of the fluid effects without actually modeling the fluid
Energies of Quantum QED Flux Tubes
In this talk I present recent studies on vacuum polarization energies and
energy densities induced by QED flux tubes. I focus on comparing three and four
dimensional scenarios and the discussion of various approximation schemes in
view of the exact treatment.Comment: 9 pages latex, Talk presented at the QFEXT 05 workshop in Barcelona,
Sept. 2005. To appear in the proceeding
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Urban Fathers Asset Building – Final Report
The Urban Fathers Asset Building (UFAB) project demonstrated the potential benefits, as well as limitations, of an innovative nexus between the child support system, fatherhood programs, and the Assets for Independence (AFI) grant-funded services. UFAB was a collaborative initiative of the Texas Office of the Attorney General (OAG), Baylor College of Medicine’s Teen Health Clinic, Covenant Community Capital Corporation (the local AFI grantee), and RAISE Texas, the statewide association of AFI grantees. This Final Report summarizes UFAB’s operational features and outcomes; depicts the demonstration’s challenges and innovative responses; reviews the accomplishments of the ancillary projects supported by BAFF funds; and assesses the prospects for sustaining demonstration practices in the Houston area, as well as extending promising practices to other areas of the state.Texas Office of the Attorney GeneralRay Marshall Center for the Study of Human Resource
Ultrathin oxides: bulk-oxide-like model surfaces or unique films?
To better understand the electronic and chemical properties of wide-gap oxide
surfaces at the atomic scale, experimental work has focused on epitaxial films
on metal substrates. Recent findings show that these films are considerably
thinner than previously thought. This raises doubts about the transferability
of the results to surface properties of thicker films and bulk crystals. By
means of density-functional theory and approximate GW corrections for the
electronic spectra we demonstrate for three characteristic wide-gap oxides
(silica, alumina, and hafnia) the influence of the substrate and highlight
critical differences between the ultrathin films and surfaces of bulk
materials. Our results imply that monolayer-thin oxide films have rather unique
properties.Comment: 5 pages, 3 figures, accepted by PR
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