Universal dielectric loss in amorphous solids from simultaneous bias and microwave field

We derive the ac dielectric loss in glasses due to resonant processes created by two-level systems and a swept electric field bias. It is shown that at sufficiently large ac fields and bias sweep rates the nonequilibrium loss tangent created by the two fields approaches a universal maximum determined by the bare linear dielectric permittivity. In addition this nonequilibrium loss tangent is derived for a range of bias sweep rates and ac amplitudes and show that the loss tangent creates a predicted loss function that can be understood in a Landau-Zener theory and which can be used to extract the TLS density, dipole moment, and relaxation rate.Comment: To appear in Physical Review Letters, 4 pages, 3 figure

The Flora of Mount Taylor

The writer has attempted to determine what species occur on Mount Taylor. This information should reveal any deviations from the expected floristic pattern as well as general distributional trends. If deviations are detected, the writer will attempt to explain them in the general discussion. Most of the answers and conclusions are of a speculative nature because of insufficient meteorologic information and comparative data from other regions

The shoulder suspension of bipedal humans and the head suspension of quadrupedal cats : a reconstruction of macroevolutionary changes of complex systems based on nautral experiments, comparative anatomy, and biomechanical analyses of extant organisms

The biological processes in macroevolutionary transformations, which result in the origin of new species and supraspecific taxa, are not directly observable in organisms with long reproductive generations and need to be extrapolated and reconstructed from physiological, anatomical, and microevolutionary processes. This dissertation reconstructs the anatomical and biomechanical changes that affected the head-neck-shoulder apparatus during the macroevolutionary transformation of a quadrupedal mammal to a bipedal one by studying two model organisms, namely the human and the cat. I hypothesize that the anatomical differences in the head-neck-shoulder apparatus of the two organisms are caused by different force regimes that act on them. I first show that the head-neck-shoulder apparatus of humans suspends the shoulders from the skull. I then demonstrate that the head-neck-shoulder apparatus of cats suspends the head from the thorax. A comparison of the two head-neck-shoulder apparatus shows that the changes necessary to modify a head suspension apparatus to a shoulder suspension apparatus are much more modest than what is usually expected to have taken place during macroevolutionary changes. Thus, it is evident that (1) small structural and configurational modifications can have significant functional and biomechanical consequences; and (2) macroevolutionary transformations of complex systems within complex organisms are amenable to analysis and evolutionary reconstruction

SAM 2 data user's guide

This document is intended to serve as a guide to the use of the data products from the Stratospheric Aerosol Measurement (SAM) 2 experiment for scientific investigations of polar stratospheric aerosols. Included is a detailed description of the Beta and Aerosol Number Density Archive Tape (BANAT), which is the SAM 2 data product containing the aerosol extinction data available for these investigations. Also included are brief descriptions of the instrument operation, data collection, processing and validation, and some of the scientific analyses conducted to date

Research reports: 1985 NASA/ASEE Summer Faculty Fellowship Program

A compilation of 40 technical reports on research conducted by participants in the 1985 NASA/ASEE Summer Faculty Fellowship Program at Marshall Space Flight Center (MSFC) is given. Weibull density functions, reliability analysis, directional solidification, space stations, jet stream, fracture mechanics, composite materials, orbital maneuvering vehicles, stellar winds and gamma ray bursts are among the topics discussed

Research Reports: 1984 NASA/ASEE Summer Faculty Fellowship Program

A NASA/ASEE Summer Faulty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The basic objectives of the programs are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The Faculty Fellows spent ten weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague. This document is a compilation of Fellows' reports on their research during the summer of 1984. Topics covered include: (1) data base management; (2) computational fluid dynamics; (3) space debris; (4) X-ray gratings; (5) atomic oxygen exposure; (6) protective coatings for SSME; (7) cryogenics; (8) thermal analysis measurements; (9) solar wind modelling; and (10) binary systems

The Current Use of Stem Cells in Bladder Tissue Regeneration and Bioengineering.

Many pathological processes including neurogenic bladder and malignancy necessitate bladder reconstruction, which is currently performed using intestinal tissue. The use of intestinal tissue, however, subjects patients to metabolic abnormalities, bladder stones, and other long-term sequelae, raising the need for a source of safe and reliable bladder tissue. Advancements in stem cell biology have catapulted stem cells to the center of many current tissue regeneration and bioengineering strategies. This review presents the recent advancements in the use of stem cells in bladder tissue bioengineering

Research Reports: 1983 NASA/ASEE Summer Faculty Fellowship Program

Thirty-five technical reports contain results of investigations in information and electronic systems; materials and processing; systems dynamics; structures and propulsion; and space sciences. Ecology at KSC, satellite de-spin, and the X-ray source monitor were also studied

On quantum equivalence of dual sigma models: SL(3)SL(3) examples

The equivalence of several $SL(3)$ sigma models and their special Abelian duals is investigated in the two loop order of perturbation theory. The investigation is based on extracting and comparing various $\beta$ functions of the original and dual models. The role of the discrete global symmetries is emphasized.Comment: Plain TEX, 24 page