Physical Sciences and Mathematics Commons^™

Low Compensation Vapor-Phase Epitaxial Gallium-Arsenide, P. C. Colter, David C. Look, D. C. Reynolds

Physics Faculty Publications

Vapor phase epitaxial gallium arsenide (GaAs) layers, with lower compensation ratios than any reported heretofore, have been reproducibly grown by the Ga/H₂/AsCl₃ method. One of these samples has been studied extensively by electrical measurements and shows an acceptor concentration of (2.0 ± 0.7)X10¹³ cm^-3 , and a compensation rate of N_A/N_D = 0.06 ± 0.02. These numbers are supported by magnetophotothermal spectroscopy and photoluminescence measurements. The preparation involves growth on [211A] substrates, and a pregrowth bakeout of the Ga source, which results in a significantly lower Zn acceptor concentration in the layer. …

Postmarsupial Development And Growth Of Pagurapseudes Largoensis Mcsweeny (Crustacea, Tanaidacea), Charles G. Messing

Marine & Environmental Sciences Faculty Articles

Postmarsupial development of the gastropod shell-inhabiting tanaidacean Pagurapseudes largoensis McSweeny is described and compared with that of Heterotanais oerstedii (Krøyer) and Neotanais micromopher Gardiner. This is the first such study of an apseudomorphan based on experimentally reared animals. P. largoensis is gonochoristic; two manca instars are typical of all tanaidaceans so far investigated. In females, the mancas are followed by two or possibly three juvenile instars (=neutra), one or two preparatory instars characterized by rudimentary oostegites, and a copulatory stage with complete marsupium. Laboratory maintained animals pass through up to three copulatory stages, each separated by a preparatory stage of …

Apl And The Numerical Solution Of High-Order Linear Differential Equations, N. A. Gershenfeld, Edward H. Schadler , '81, Oleksa-Myron Bilaniuk

Physics & Astronomy Faculty Works

An Nth‐order linear ordinary differential equation is rewritten as a first‐order equation in an N×N matrix. Taking advantage of the matrix manipulation strength of the APL language this equation is then solved directly, yielding a great simplification over the standard procedure of solving N coupled first‐order scalar equations. This eases programming and results in a more intuitive algorithm. Example applications of a program using the technique are given from quantum mechanics and control theory.

The Probe, Issue 35 - August 1983

The Probe: Newsletter of the National Animal Damage Control Association

The Probe National Animal Damage Control Association
No. 35 August, 1983
Eastern ADC Conference
A Methodology for Assessing Indirect Costs of Predation Control: A Study of Wyoming Sheep Producers
Snakes of the Southeastern United States
Bighorns
Anticoagulant rodenticide—diphacinone
Canada geese
Letters to Ye Ed
Quiet! Our Legislators are Thinking
Prevention and Control of Wildfire Damage
1983 National Environmental Survey
Vulture predation situations
Seminars on vertebrate pest control
Coyotes
Reduction in the ADC program

Parameter Optimization Using A Hierarchical System Of Learning Automata, Brian T. Mitchell

Dissertations

Many problems in adaptive control, pattern recognition, filtering, identification, and artificial intelligence can be viewed as parameter optimization problems. The learning automation approach to these problems has two distinct advantages over the classic hill climbing methods: (1) the parameter space need not be metric and (2) a global rather than local optimum can be found. Unfortunately, these advantages do not come without corresponding difficulties, namely the problem of high dimensionality. A hierarchical system of learning automata has been used to reduce this problem somewhat, but inefficiencies still remain since the current hierarchical system was balanced and static hierarchical learning automaton …

Center-Of-Mass Properties Of Composite Systems Subject To Non-Linear External Interactions, James A. Lock

Physics Faculty Publications

If two bound nonrelativistic quantum particles are each subject to a nonlinear external potential, their Schrödinger equation does not separate in relative and center-of-mass coordinates. For this case, the details of internal state of the composite affect its center-of-mass properties. The extent of this internal state influence is examined for an exactly soluble one-dimensional model system.

Practices For Protecting And Enhancing Fish And Wildlife On Coal Mined Land In The Uinta-Southwestern Utah Region, Bettina R. Proctor, Science Applications, Inc., Richard W. Thompson, Jane E. Bunin, Kenneth W. Fucik, George R. Tamm, Edward G. Wolf, U.S Department Of The Interior- Fish And Wildlife Service

All U.S. Government Documents (Utah Regional Depository)

This handbook contains information on the best current practices to minimize disturbances and adverse impacts of surface mining on fish and wildlife resources. Current state and federal legislation was reviewed to determine those practices which were most compatible with the best technology currently available, fish and wildlife plans, and reclamation plans for the Uinta-Southwestern region of the U.S. The information presented includes risks, limitations, approximate costs, and maintenance and management requirements of each practice. Plans for the restoration of specific habitats, according to the best current practices, are also included.

An Optimal Design Of Relational Data Model, Pissamai Amatayakul

Masters Theses

The objective of this study was to propose a design methodology to support a designed in mapping a conceptual model to a logical model. The system was created as a semiinteractive software to produce an optimal relational data model for a given database. The software was developed by combining a well known normalization method from a theory of relational data model which was presented by Codd and the ideas of new normal form which were presented recently by many researchers in the field of database design. The complete description of data objects and their associations are initially defined as a …

A High Resolution Ground Magnetic Study Of Part Of The Albion-Scipio Trend, Steven James Hoin

Masters Theses

A detailed high resolution ground magnetic survey was conducted over part of the Albion-Scipio Oil Field Trend. The purpose of the survey was to delineate any magnetic anomalies associated with the trend. A field method using two magnetometers was employed. Sixteen simultaneous readings were taken at a mobile and a base station, and the field operator read the total field values using a 'T ', or similar pattern. This method eliminated much of the noise associated with ground surveys. The resulting residual magnetic map indicates that the basement rocks consist of mafic and felsic, dikes and plutons. Several discontinuities are …

Design, Construction, And Testing Of A Microprocessor-Controlled Interface Between Analog Geophysical Equipment And A Digital Cassette Recorder, Mohd. Nawawi Mohd. Nordin

Masters Theses

A Digital Data Acquisition System (DDAS) microcomputer was designed and constructed to interface between a six-channel analog seismograph and a digital cassette recorder. The DDAS microcomputer is a relatively inexpensive microcomputer built around the popular Z-80 microprocessor chip. It is portable and has 26K bytes of memory. It was designed to convert analog data in to digital with some processing performed before storing on the digital cassette recorder, for later analysis. The same hardware or circuitry of the DDAS microcomputer can perform other functions and work with other geophysical equipment by changing the software of the microcomputer.

A Microprocessor Controlled Pulsed Hollow Cathode Lamp For An Atomic Absorption Spectrometer, James B. Schilling

Masters Theses

A Jarrell-Ash Atomic Absorption/Flame Emission 82-360 Spectrometer was interfaced to a Heathkit ETA-3400 microprocessor. The microprocessor is used to pulse the hollow cathode lamp from a "steady" current to a "peak " current during the opening of the chopper. The current from the photomultiplier-tube is converted to a proportional voltage which is supplied to a sample-and-hold circuit. A successive approximation routine is used to convert the voltage to a representative digital value. Digital values are obtained for the "blank" and "sample" and are used to calculate percent absorption values. The system can also be used to obtain emission values.

The …

Transport Properties Of Ground State Nitrogen Atoms, James C. Rainwater, Louis Biolsi Jr., Kevin J. Biolsi, Paul M. Holland

Chemistry Faculty Research & Creative Works

Transport properties of dilute monatomic gases depend on the two body atom-atom interaction potential. When two ground state (⁴S) nitrogen atoms interact, they can follow any of four potential energy curves corresponding to the N₂ molecule; the X ¹Σ⁺_g, A³Σ⁺_u, ⁵Σ⁺_g, and ⁷Σ⁺_u curves. Transport collision integrals for the ¹Σ⁺_g and ³Σ⁺_u states have been calculated by representing the potentials for these states with the Hulburt-Hirschfelder potential. The⁵Σ⁺_g state has a …

A Uniform System For Data Base Directories, Karl Chang

Masters Theses

The objective of this study is to provide an efficient uniform system for data base directories, so that every file in the data base will have the same type of efficient directory. Data base directories will then be uniformly generated, updated and maintained.

The uniform system which is developed here can handle not only discrete attributes, but also range attributes. For the range attributes, it provides the uniform ranges (i.e., a set of ranges such that the records are distributed uniformly between ranges.)

In this thesis, the design and implementation of the hybrid B-plus tree and inverted files which is …

Generalized Response Of Chemiluminescence Analyzers, A. A. Mehrabzadeh, Robert J. O'Brien, Thomas M. Hard

Chemistry Faculty Publications and Presentations

The mass flow and chemical kinetic equations for a gaseous chemiluminescence (CL) analyzer are formulated and solved. The resultant equation can be used to predict the absolute response of the analyzer as a function of the sample flow rate, the sample gas pressure, the chamber pressure, the chamber volume, the mass flow rate and mole fraction of the reagent gas, and the rate constants of the relevant chemical processes. Thus, the equation allows optimization of these parameters. It is shown that for varying sample pressure the analyzer can be used to measure either concentration or mole fraction and that interfering …

Analytical Pyrolysis Of Eastern Shales, Kenneth Naples

Masters Theses & Specialist Projects

The effects of pyrolysis interval, ceiling temperature, heating rate and mesh size on both the pyrolysis yield and relative product distribution for two eastern oil shales (Sunbury and Cleveland) were studied. An extension of the technique of analytical pyrolysis (pyrolysis-gas chromatography) was used. This extension employed a Chemical Data System (C.D.S.) Model 382 Extended Pyroprobe and a C.D.S. Model 310 Concentrator which enabled the pyrolysis products to be collected into a trap system. After completion of a predetermined heating interval, the trap was pulse heated to 250°C and the high and low volatile components were back-flushed into the injection port …

Rappahannock River Slack Water Data Report: Temperature, Salinity, Dissolved Oxygen 1970-1980, T. J. Brooks

Reports

This report contains station locations, survey schedules, field procedures, sample handling procedures, and data reduction and storage procedures. In addition, 11 years of contoured temperature, salinity, and dissolved oxygen data is presented.

Volterra Integral Equations In Abstract Cones And Monotone Iterative Technique, G. R. Shendge

Mathematics Technical Papers

The objective of this paper is to develop monotone technique for obtaining extremal solutions of Volterra integral equations in abstract Banach spaces via coupled lower and upper quasi-solutions. To generate the iterates, different schemes are given which would be of special interest from computational point of view.

Pressure Method For The Numerical Solution Of Transient, Compressible Fluid Flown, Donald Greenspan, Vincenzo Casulli

Mathematics Technical Papers

In this paper the pressure method for incompressible fluid flow simulation is extended and applied to the numerical simulation of compressible fluid flow. The governing equations, obtained from the physical principles of conservation of momentum, mass and energy, are first studied from a characteristic point of view. Then they are discretized with a semi-implicit finite difference technique in such a fashion that the Courant stability condition on the time step is not required. The resulting algorithm is fast, accurate and applies to problems with arbitrarily large speed of sound. As an example, the computer simulation of the von Kármán vortex …

Unification Of Ernst-Equation Backlund Transformations Using A Modified Wahlquist-Estabrook Technique; Wahlquist-Estabrook, B. Kent Harrison

Faculty Publications

The three known Backlund transformations for the Ernst equation are derived using a modification of the Wahlquist-Estabrook prolongation procedure. The modification requires that the equation to be studied be cast into a set of differential forms and their exterior derivatives, such that all coefficients are constant (a "CC ideal''). Analysis of the resulting equations produces 16 solutions composed of the three basic transformations combined with identity and other essentially trivial transformations. The group structure of the transformations is discussed. A Backlund transformation (already known) for the Ernst-Maxwell equations can be found by the same method. Promising generalizations are mentioned.

Derivation And Test Of Predictions Of A Discrete Latent State Model For Signed Number Addition Test Performance, Kentaro Yamamoto

Dissertations and Theses

This study is an investigation of the performance of a discrete latent state model devised by Paulson (1982) to account for signed-number arithmetic test data gathered by Birenbaum and Tatsuoka (1980). One hundred twenty nine students took a test which consists of sixteen item types with four parallel arithmetic items of each type. The present study utilizes the five addition item types of four items each; hence, there are four parallel subtests. Responses to the addition items can be analyzed in terms of two components: the sign component (is the sign correct?), and the absolute value component (is the size …

The Metal In The Polarisable Interface Coupling With The Solvent Phase, Jerry Goodisman, Jean Paul Badiali, Martin Luc Rosinberg

Chemistry - All Scholarship

A quantum mechanical treatment of the conduction electrons of a metal in a polarisable interface shows that they can make an appreciable contribution to the electrical capacitance. Results for six metals are given, showing how differences in metal properties account qualitatively for experimentally observed differences in interfacial capacities, when the solvent is replaced by a dielectric film. To justify the neglect of solvent structure when metal properties are treated, the coupling between metal and solvent is discussed for orientable point solvent dipoles, and for a representation of the solvent polarisation by a pair of charged planes. The electron profile affects …

Activity Coefficient And The Einstein Relation, Peter T. Landsberg, Albert G. Guy

Aerospace, Physics, and Space Science Faculty Publications

A connection between the activity coefficient of current carriers and the Einstein relations is established by two methods, one based on normal semiconductor concepts and one based on irreversible thermodynamics. The connection holds for all densities of states, for Fermi degeneracy, and in the presence of heavy doping.

Order Of Phase Transitions In A Field Theory, V. Parameswaran Nair

Publications and Research

The relation between the gauge or global nature of a symmetry being broken and the order of the associated phase transition is clarified. First-order phase transitions in gauge theories are related to the asymptotic freedom of the Φ³ interaction in six dimensions. Spontaneous violation of lepton number in the standard electroweak theory provides a nontrivial illustration of our results.

Renormalization And Radiative-Corrections At Finite Temperature, Jf Donoghue, Br Holstein

Barry R Holstein

We discuss the renormalization prescription for fermions at finite temperature and describe the procedure for calculating radiative corrections. Novel features arise, such as a lack of explicit Lorentz invariance, 1k2 singularities, and the absorption of soft photons from the background heat bath. The methods are illustrated by explicit calculation of the electron renormalization and the radiative corrections to H-->e+e- (with H being spin zero) in finite-temperature QED.

Scs 79: The Lower Topology For Continuous Lattices Is A Monadic Functor, Oswald Wyler

Seminar on Continuity in Semilattices

No abstract provided.

Water Current, Volume 15, No. 4, July/August 1983

Water Current Newsletter

Reorganization of Water Center Staff
1983 Water Law Developments
Water Research Funding
Conference on Pick-Sloan Plan
Calls for Papers
Research Review: Water and Energy Conservation Using Center Pivot Irrigation and Reduced Tillage Systems

On The Generators Of The First Homology With Compact Supports Of The Weierstrass Family In Characteristic Zero, Goro Kato

Mathematics

No abstract provided.

Stop Rule Inequalities For Uniformly Bounded Sequences Of Random Variables, Theodore P. Hill, Robert P. Kertz

Research Scholars in Residence

If X₀, X₁, ... is an arbitrarily-dependent sequence of random variables taking values in [0,1] and if V( X₀, X₁, ...) is the supremum, over stop rules t, of EX_f, then the set of ordered pairs {(x , y): x = V( X₀, X₁, ..., X_n and y = E(max_{jXj for some X0, ... , Xn} is precisely the set Cn = {(x, y): x < y < x(1 + n …}

Effect Of Nitrogen Fertilization On Fall Stockpiled Ky 31 Fescue, Kenneth L. Wells

Soil Science News and Views

Much interest has developed during the past several years on improving utilization of tall fescue by accumulating its growth during the fall and delaying grazing until late fall and winter. This technique takes advantages of the buildup of sugars in the herbage which normally takes place as seasonal temperatures cool to near the freezing point. UK forage research has shown that content of sugars in tall fescue herbage can increase from around 8 percent in late summer to around 20 percent after the first few frosts have occurred in late fall. This sugar buildup greatly increases the feed value of …

Volume 7, Number 7 (July 1983), The Solar Ocean Energy Liaison

The OTEC Liaison

No abstract provided.