New developments in dry and wet etching, ohmic contacts and epitaxial growth of Ill-V nitrides are reported. These make possible devices such as microdisk laser structures and GaAs/AlGaAs heterojunction bipolar transistors with improved InN ohmic contacts.

Ensemble concert presented at the UNT College of Music Kenton Hall.

An understanding of the interactions of neutrons and protons below a few hundred MeV with nuclei is important for a number of applications. In this paper, two new applications are discussed: radiation transport calculations of energy deposition in fast neutron and proton cancer radiotherapy to optimize the dose given to a tumor; and intermediate-energy proton accelerators which are currently being designed for a range of applications including the destruction of long-lived radioactive nuclear waste. We describe nuclear theory calculations of direct, preequilibrium, and compound nucleus reaction mechanisms important for the modeling of these systems.

As part of a continuing study of the physics of matter under extreme conditions, I give some results on matter at extremely low density. In particular I compare a quantum mechanical calculation of the pressure for atomic hydrogen with the corresponding pressure given by Thomas-Fermi theory. (This calculation differs from the ``confined atom`` approximation in a physically significant way.) Since Thomas-Fermi theory in some sense, represents the case of infinite nuclear charge, these cases should represent extremes. Comparison is also made with Saha theory, which considers ionization from a chemical point of view, but is weak on excited-state effects. In this theory, the pressure undergoes rapid variation as electron ionization levels are passed. This effect is in contrast to the smooth behavior of the Thomas-Fermi fixed temperature, complete ionization occurs in the low density limit, I study the case where the temperature goes appropriately to zero with the density. Although considerable modification is required, Saha theory is closer to the actual results for this case than is Thomas-Fermi theory.

Most of the published theoretical and calculational effort on unsupported, ordered, ultra-thin films (``UTF``) in vacuo has focused on the thickest computationally feasible systems as models for surface properties of semi-infinite slabs. Crystalline periodic length scales in two cartesian dimensions combined with molecular- scale thickness in the third, however, make UTF`s strong candidates for the occurrence of quantum interference effects. Many UTF properties were predicted first from jellium slab models. A noteworthy prediction was that there would be large oscillations in the work function as a function of layer number. Extensive calculations on a variety of N-layers (N = 1,2,3... atomic planes) using all-electron, full-potential, local-spin-density approximation techniques show that the work function oscillation is weaker than expected but that there are significant layer-number dependences in the equilibrium lattice parameters, inter-planar spacings, electronic structure, density of states, and electronic stopping power. This paper reviews our own calculations as well as some others. Our objectives include the discernment of systematics within UTF`s, systematics in relationship to their counterpart crystals, relationship with surface properties, and appraisal of challenges to current models and methods.

In two dimensional systems in a strong magnetic field, electrons can be transformed into composite Fermions (CF) by attaching to each a fictitious flux tube (carrying flux {Phi}) and fictitious charge q, where the product q{sup {Phi}} is a multiple of 2 {Pi}. In the mean field approximation, this transformation converts a fractionally filled electron Landau level into an integrally filled CF Landau level. This integrally filled CF Landau level corresponds to the ground state of a Laughlin incompressible fluid. Excited states are described by the n{sub QE} and n{sub QH}, the numbers of quasielectron and quasihole CF excitations. For N electrons on the surface of a sphere the energy and angular momentum of a quasihole (or quasielectron) are {var_epsilon}{sub QH} and l{sub QH}=1/2(N+n{sub QH}-n{sub QE}-1) (or {var_epsilon}{sub QE} and l{sub QE}=l{sub QH}+1). The lowest energy sector of the energy spectrum contains the minimum number of CF excitations consistent with the value of N and the degeneracy of the lowest Landau level, 2S+1. The first excited sector contains one additional QE-QH pair. The total angular momentum L is obtained by adding the angular momenta of QE excitations and QH excitations treated as distinguished sets of Fermions. In the absence of …

Abstract: The U.S. Geological Survey and the Corporación Venezolana de Guayana, Técnica Minera, C.A., conducted a cooperative mapping, exploration, and mineral resource estimation study in Venezuela from 1987 to 1992. The work was conducted in the Venezuelan Guayana Shield, an Archean to Early and Middle Proterozoic craton in southern and eastern Venezuela of almost 415,000 km2 that is mostly covered by jungle and savanna. Results obtained from this project contribute a new understanding of the geology and evolution of the Venezuelan Guayana Shield and the nature of its mineral occurrences. Personnel from Técnica Minera, C.A., were trained both in the field and in the office to conduct modern mineral exploration and geologic mapping and research programs. This five-year project was supported financially by the Corporación Venezolana de Guayana.

Article on assessing potential impacts of CO2 and deforestation induced climate change on maize and black bean in Venezuela.

Quarterly publication of the German-Texan Heritage Society providing information about news and events related to the work of the organization as well as stories, articles, genealogical data and other information of interest to members collected from representatives across Texas.

This report contains the results of efforts under the six tasks of the Eighth Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each of the tasks. A statement of each task, taken from the agreement, is presented on the first page of each section.

The continued growth of highway traffic in the United States has led to unwanted urban traffic congestion as well as to noticeable urban air quality problems. These problems include emissions covered by the 1990 Clean Air Act Amendments (CAAA) and 1991 Intermodal Surface Transportation Efficiency Act (ISTEA), as well as carbon dioxide and related {open_quotes}greenhouse gas{close_quotes} emissions. Urban travel also creates a major demand for imported oil. Therefore, for economic as well as environmental reasons, transportation planning agencies at both the state and metropolitan area level are focussing a good deal of attention on urban travel reduction policies. Much discussed policy instruments include those that encourage fewer trip starts, shorter trip distances, shifts to higher-occupancy vehicles or to nonvehicular modes, and shifts in the timing of trips from the more to the less congested periods of the day or week. Some analysts have concluded that in order to bring about sustainable reductions in urban traffic volumes, significant changes will be necessary in the way our households and businesses engage in daily travel. Such changes are likely to involve changes in the ways we organize and use traffic-generating and-attracting land within our urban areas. The purpose of this review is to …

Semimonthly student newspaper from St. Edward's University in Austin, Texas that includes news and information of interest to the college community along with advertising.

Semimonthly student newspaper from St. Edward's University in Austin, Texas that includes news and information of interest to the college community along with advertising.

Weekly student newspaper from Howard Payne University in Brownwood, Texas that includes local, state and campus news along with advertising.

Semimonthly student newspaper from St. Edward's University in Austin, Texas that includes news and information of interest to the college community along with advertising.

Student newspaper from St. Edward's University in Austin, Texas that includes news and information of interest to the college community along with advertising.

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.

Quarterly newspaper from St. Edward's University in Austin, Texas that includes news and information of interest to the alumni community along with advertising.

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.

A weekly student newspaper from the Rice University in Houston, Texas that includes campus news and commentaries along with advertising.

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.

Weekly newspaper from Wynnewood, Oklahoma that includes local, state, and national news along with advertising.

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.