239,997 research outputs found
Application of NASTRAN to TFTR toroidal field coil structures
The primary applied loads on the TF coils were electromagnetic and thermal. The complex structure and the tremendous applied loads necessitated computer type of solutions for the design problems. In the early stage of the TF coil design, many simplified finite element models were developed for the purpose of investigating the effects of material properties, supporting schemes, and coil case material on the stress levels in the case and in the copper coil. In the more sophisticated models that followed the parametric and scoping studies, the isoparametric elements, such as QUAD4, HEX8, and HEXA, were used. The analysis results from using these finite element models and the NASTRAN system were considered accurate enough to provide timely design information
Studies in a transonic rotor aerodynamics and noise facility
The design, construction and testing of a transonic rotor aerodynamics and noise facility was undertaken, using a rotating arm blade element support technique. This approach provides a research capability intermediate between that of a stationary element in a moving flow and that of a complete rotating blade system, and permits the acoustic properties of blade tip elements to be studied in isolation. This approach is an inexpensive means of obtaining data at high subsonic and transonic tip speeds on the effect of variations in tip geometry. The facility may be suitable for research on broad band noise and discrete noise in addition to high-speed noise. Initial tests were conducted over the Mach number range 0.3 to 0.93 and confirmed the adequacy of the acoustic treatment used in the facility to avoid reflection from the enclosure
Observing a Light CP-Violating Higgs Boson in Diffraction
Light CP-violating Higgs bosons with mass lower than 70 GeV might have
escaped detection in direct searches at the LEP collider. They may remain
undetected in conventional search channels at the Tevatron and LHC. In this
Letter we show that exclusive diffractive reactions may be able to probe for
the existence of these otherwise elusive Higgs particles. As a prototype
example, we calculate diffractive production cross-sections of the lightest
Higgs boson within the framework of the Minimal Supersymmetric Standard Model
with explicit CP violation. Our analysis shows that the challenging regions of
parameter space corresponding to a light CP-violating Higgs boson might be
accessible at the LHC provided suitable proton tagging detectors are installed.Comment: 9 pages, LaTeX, 2 figures, version as to appear in Phys. Rev.
Triply Special Relativity
We describe an extension of special relativity characterized by {\it three}
invariant scales, the speed of light, , a mass, and a length .
This is defined by a non-linear extension of the Poincare algerbra, ,
which we describe here. For , becomes the Snyder
presentation of the -Poincare algebra, while for it
becomes the phase space algebra of a particle in deSitter spacetime. We
conjecture that the algebra is relevant for the low energy behavior of quantum
gravity, with taken to be the Planck mass, for the case of a nonzero
cosmological constant . We study the modifications of
particle motion which follow if the algebra is taken to define the Poisson
structure of the phase space of a relativistic particle.Comment: 13 page
Temperature Dependence Of The Electrical Resistivity Of LaxLu1-xAs
We investigate the temperature-dependent resistivity of single-crystalline films of LaxLu1-xAs over the 5-300 K range. The resistivity was separated into lattice, carrier and impurity scattering regions. The effect of impurity scattering is significant below 20 K, while carrier scattering dominates at 20-80 K and lattice scattering dominates above 80 K. All scattering regions show strong dependence on the La content of the films. While the resistivity of 600 nm LuAs films agree well with the reported bulk resistivity values, 3 nm films possessed significantly higher resistivity, suggesting that interfacial roughness significantly impacts the scattering of carriers at the nanoscale limit. (C) 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.Microelectronics Research Cente
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