Digital Commons Network^™

A Validation Of The Parameterized Real-Time Ionospheric Specification Model (Prism) Version 1.7b, Shawn D. Filby

Theses and Dissertations

The most current version of the Parameterized Real-time Ionospheric Specification Model (PRISM), version 1.7b, was validated using Digital Ionospheric Sounding System (DISS) measurements of F2 layer critical frequency (foF2) and F2 peak electron density height (hmF2) as the "ground truth." PRISM was executed, first, with no real-time input parameter and, second, with Global Positioning System (GPS) Total Electron Content (TEC) measurements as the sole real-time parameter. Hourly values of hmF2 and foF2 over 123 days in 1994-1996 (solar minimum conditions) and covering three seasons (equinox, summer solstice, and winter solstice) were compared for Wallops Island, Virginia, and Point Arguello, California, …

1997 November, Office Of Communications & Marketing, Morehead State University.

Morehead State Press Release Archive, 1961 to the Present

Morehead State University press releases for November of 1997.

Searches For Scalar Top And Scalar Bottom Quarks At Lep2, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Searches for scalar top and bottom quarks have been performed with data collected by the ALEPH detector at LEP. The data sample consists of 21.7 pb−1 taken at √ s = 161, 170, and 172 GeV and 5.7 pb−1 taken at √ s = 130 and 136 GeV. No evidence for scalar top quarks or scalar bottom quarks was found in the channels ˜t → cχ, ˜t → bℓν˜, and b˜ → bχ. For the channel ˜t → cχ a limit of 67 GeV/c 2 has been set on the scalar top quark mass, independent of the mixing angle between …

Updated Measurement Of The Τ Lepton Lifetime, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A new measurement of the mean lifetime of the τ lepton is presented. Three different analysis methods are applied to a sample of 90000 τ pairs, collected in 1993 and 1994 with the ALEPH detector at LEP. The average of this measurement and those previously published by ALEPH is ττ = 290.1±1.5±1.1fs.

Apportioning Basis: Partial Sales, Bargain Sales And The Realization Principle, Stephen B. Cohen

San Diego Law Review

The International Revenue Code generally taxes appreciation in the value of property only on realization, defined to mean when property is sold or exchanged. In measuring gain on a sale or exchange, an allowance must be made for the return of capital, referred to as basis. In partial sales, it is the general rule that the basis is apportioned, in a fraction equal to the property that has been sold. This same rule applies to “bargain” sales—those where property is intentionally sold at less than its fair market value.

This article makes logical, legal, and equitable arguments to support the …

Radiation Imaging Operators Applied To The Detection Of Velocity And Density Contrast Boundaries, Md. Ishfaqur Raza, Richard E. Dubroff, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A procedure for imaging interfaces formed by simultaneous density and velocity contrasts in acoustic media is described. The procedure is based on the properties of radiation imaging operators - a class of linear differential operators parametrically dependent on the acoustic properties of the media. An example of this procedure is demonstrated through the use of numerical simulation. Results, in the form of interface images, are shown, assuming the bulk acoustic characteristics (velocity and density) on both sides of the interface are known.

A Hybrid Fem/Mom Technique For Electromagnetic Scattering And Radiation From Dielectric Objects With Attached Wires, Mohammad Wares Ali, Todd H. Hubing, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid formulation is presented, which combines the method of moments (MOM) with the edge-based vector finite element method (FEM) to solve electromagnetic radiation problems from structures consisting of an inhomogeneous dielectric body of arbitrary shape attached to one or more perfectly conducting bodies. While either method alone fails to model these structures efficiently, a combination of both finite element and moment methods provides an excellent way to solve these problems. The FEM is employed to handle the interior domain of inhomogeneous dielectric bodies and the method of moments is used to develop surface integrals that relate the field quantities …

Modeling Of Surface Hairline-Crack Detection In Metals Under Coatings Using An Open-Ended Rectangular Waveguide, Christian J. Huber, Habibollah Abiri, Stoyan I. Ganchev, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

A surface-breaking hairline crack or a narrow slot in a metallic specimen when scanned by an open-ended rectangular waveguide probe influences the reflection-coefficient properties of the incident dominant mode. Subsequent recording of a change in the standing-wave pattern while scanning such a surface results in what is known as the crack characteristic signal. Since microwave signals penetrate inside dielectric materials, this methodology is capable of detecting cracks under dielectric coatings of various electrical thicknesses as well. To electromagnetically model the interaction of an open-ended rectangular waveguide with a surface-breaking hairline crack under a dielectric coating, the dielectric-coating layer is modeled …

Nonlinear Response Theory: Transport Coefficients For Driving Fields Of Arbitrary Magnitude, Paul Ernest Parris, Marek Kus, David H. Dunlap, Vasudev M. Kenkre

Physics Faculty Research & Creative Works

A theory of nonlinear response is developed for driving fields of arbitrary magnitude. Exact and usable expressions are provided for electrical and thermal mobility, and related transport coefficients, in terms of correlation functions of the system. A generalization into the nonlinear domain is provided of the Wiedemann-Franz law connecting electrical and thermal response and of the Einstein relation relating the diffusion constant and the mobility.

An Investigation Of The Heat Transfer Suppression Mechanisms In The Pool Boiling Of Aqueous Solutions Of Ethylene Glycol, Lucas Alves

Theses

An experimental investigation of the heat transfer behavior of a binary system, whose constituents are water and ethylene glycol, is undertaken. The objectives of this study are: 1 . To conduct a comprehensive literature search. 2. To examine the effect of certain parameters on the heat transfer suppression mechanisms of binary systems. 3 . To gather new data for boiling heat transfer of aqueous ethylene glycol solutions, over the entire range of concentrations. The dilute concentration range, with solutions of 0.0 - 0. 1 mass fractions, is given special attention in clarifying what are the effects of surface tension, mass …

Analysis Of Uranium Oxide Weathering By Molecular Spectroscopy, Matthew S. Zickafoose

Theses and Dissertations

A preliminary study of the weathering of uranium oxide particles diluted in diamond dust at ambient environmental conditions is presented. The primary weathering reaction is oxidation of the uranium from the 4 to 6 oxidation state, although formation of compounds such as carbonates and hydroxides is possible. Identification of the state of uranium oxide has been attempted using luminescence spectroscopy and diffuse reflectance Fourier transform infrared spectroscopy DRIFTS. Luminescence spectra of nominal samples of three common oxides, UO3, U3O8, and UO2, have been measured showing significant spectral differences in peaks at 494 nm, 507 nm, 529 nm, and 553 nm. …

Task Scheduling In Networks, Cynthia Phillips, Clifford Stein, Joel Wein

Dartmouth Scholarship

Scheduling a set of tasks on a set of machines so as to yield an efficient schedule is a basic problem in computer science and operations research. Most of the research on this problem incorporates the potentially unrealistic assumption that communication between the different machines is instantaneous. In this paper we remove this assumption and study the problem of network scheduling, where each job originates at some node of a network, and in order to be processed at another node must take the time to travel through the network to that node.

Our main contribution is to give approximation algorithms …

An Integrated Environment For Problem Solving And Program Development, Fadi Pierre Deek

Dissertations

A framework for an integrated problem solving and program development environment that addresses the needs of students learning programming is proposed. Several objectives have been accomplished: defining the tasks required for program development and a literature review to determine the actual difficulties involved in learning those tasks. A comprehensive Study of environments and tools developed to support the learning of problem solving and programming was then performed, covering programming environments, debugging aids, intelligent tutoring systems, and intelligent programming environments. This was followed by a careful analysis and critique of these systems, which uncovered the limitations that have prevented them from …

Fractionally Sampled Decorrelating Detectors For Time-Varying Rayleigh Fading Cdma Channels, Huaping Liu

Dissertations

In this dissertation, we propose novel decorrelating multiuser detectors in DSCDMA time-varying frequency-nonselective and frequency-selective fading channels and analyze their performance. We address the common shortcomings of existing multiuser detectors in a mobile environment, such as detector complexity and the error floor. An analytical approach is employed almost exclusively and Monte Carlo simulation is used to confirm the theoretical results. Practical channel models, such as Jakes' and Markovian, are adopted in the numerical examples.

The proposed detectors are of the decorrelating type and utilize fractional sampling to simultaneously achieve two goals: (1) the novel realization of a decorrelator with lower …

Analysis Of Safe Separation Distances From Natural Gas Transmission Pipelines, James Stephen Haklar

Dissertations

Accidental rupture of natural gas transmission pipelines with subsequent ignition of the escaping gas can result in the loss of life and property. In the United States, current means of protecting both the pipeline and the public include the establishment of class locations, in which specific pipeline design, construction and operation requirements must be attained. In addition, distances at which the pipelines can be safely set back from the community, called safe separation distances, have been developed in some European countries (e.g., Great Britain, the Netherlands) through use of risk assessment principles. However, to date there has been no simple, …

Automobile Air Bag Inflation System Based On Fast Combustion Reaction, Yacoob Tabani

Dissertations

Current automobile air bag inflator technology is complex, expensive and environmentally unsafe. A new and novel air bag inflator based on fast combustion reactions of methane-oxygen mixtures has been developed and studied. The thermodynamics and mass flow parameters of this new inflator have been modeled and found to be in agreement with experimental results.

The performance of the fast combustion inflator was evaluated in terms of pressure-time relationships inside the inflator and in a receiving tank simulating an air bag as well as the temperature-time relationship in the tank.

In order to develop this fast combustion inflator, several critical issues …

Modeling Study On The Neopentyl+ O2 Reaction System And Experimental And Modeling Study On Mtbe Pyrolysis And Oxidation, Ru Wei

Dissertations

A modeling study on neopentyl radical + O₂ reaction system is conducted in this study. Thermodynamic parameters on all species and important transition states are calculated. A thermochemical kinetic analysis is performed.

Thermodynamic parameters are estimated using group additivity with HBI groups. Transition state energies are evaluated from experimental and theoretical data in the literature, combined with elementary reaction modeling to account for temperature effects. Transition state structures, vibration frequencies and entropies are determined from semi-empirical calculations, MOPAC PM3. Kinetics are analyzed with quantum RRK theory for k(E) coupled with modified strong collision analysis of Gilbert et al for …

Diffusive And Wavelike Phenomena In Thermal Processing Of Materials, John A. Pelesko

Dissertations

Contemporary materials science abounds with novel processing methods. Devices such as lasers, microwave sources, and electron beam guns, provide unprecedented control over the deposition of energy within a material. The modern materials scientist has the ability to deposit energy volumetrically, to precisely control the location of energy deposition within a material, and to deposit energy in extremely short intervals of time. While making possible numerous thermal processing methods, these devices also push the limits of our understanding of the response of materials to energy deposition. In order to optimize and control these processing methods, it becomes necessary to further our …

Electrocatalytic Control Of Exhaust Soot, Victor L. Callahan

Dissertations

The feasibility of combining electrostatic precipitation and use of a catalytic wall in a straight tube reactor as a means of destroying soot particles was investigated. Enhanced particle diffusion to the wall by an applied electric field provided the means of particle capture for subsequent catalytic oxidation at the active surface in a small length tube.

Soot particles flowing in a gas stream are influenced by the following transport mechanisms: convective flux as a result of bulk flow, diffusion flux as a result of particle concentration or number density gradient, and an electrostatic flux from the coulombic attraction as charged …

Volume 33 - Issue 8 - Friday, October 31, 1997, Rose Thorn Staff

The Rose Thorn Archive

The Rose Thorn, Rose-Hulman's independent student newspaper.

The Bates Student - Volume 127 Number 07 - October 31, 1997, Bates College

The Bates Student

No abstract provided.

Inconsistency As Consistency: An Optimal Policy For Human Rights, Ibpp Editor

International Bulletin of Political Psychology

This article contrasts two common cognitive approaches employed by United States (US) politicians in furthering human rights throughout the world.

Volume 35, Number 11: October 31, 1997, University Of North Dakota

University Letter Archive

No abstract provided.

A Decision Support System For The Equipment Selection Of Robotic Manufacturing Cells, Lars Johan Resare

Theses

Considering the principles of concurrent engineering, a Decision Support System (DSS) is developed to aid in the equipment selection of robotic manufacturing cells. The objective is to synchronously and simultaneously select proper equipment for the cell to provide efficient performance, subject to operational and budgetary constraints.

The DSS consists of several modules, including a data base that houses the specifications of equipment available in the market place, a first cut selection module, and an optimization engine. In its development, the optimization scheme utilizes analytical models and algorithms that capture different sources of variability in production, such as tolerances, clearances and …

Interactive And Batch Creation Of Oodb Medical Vocabularies, Muhammad Arif

Theses

Controlled vocabularies are becoming popular for knowledge representation and querying. They are particularly helpful in the medical field since they can unify disparate terminologies and provide information in a compact, comprehensible manner. In this thesis, we present a mechanism to create OODB controlled medical vocabularies from flat-file format. We also describe a tool by which a user can interactively create, edit and browse the vocabulary. For better understanding of the structure of the vocabulary we designed our interface as a graphical editor and browser. The user of this interface will typically be a medical expert who either wants to add …

Structured Document Comparison And Scientific Data Mining On The World Wide Web, Philip B. Johnson

Theses

The usefulness and accessibility of programs and systems have become important issues for users and researchers alike. A program's usefulness can lw measured by the frequency with which it is used. From the author's or maintainer's point of view, the frequency of usage can be determined by how often a request for the software is received. In the past, a user became aware of a particular tool through various means, and contacted the author or maintainer to obtain a copy of it. This presented difficulties, ranging from language barriers to machine incompatibilities to control of the use of the program. …

Modeling Of Deformed Swept Volumes With Sde And Its Applications To Nc Simulation And Verification, Feng Lu

Theses

Representation of swept volumes has important applications in NC simulation and verification as well as robot-motion planning. Most research on .the representation of swept volumes has been limited to rigid objects. In this study, a sweep deferential equation (SDE) approach is presented for the representation of deformed swept volumes generated by flexible objects.

The deformed swept volume analysis is integrated with machining physics to account for tool deformation/deflection for the NC simulation. End milling is modeled and analyzed and the tool deformations are calculated and integrated with the SDE program. A program is developed in C++ for the generation of …

Removal And Recovery Of Vocs And Oils From Surfactant-Flushed Recovered Water By Membrane Permeation, Ashish Nagnath Saraf

Theses

Surfactant-enhanced subsurface remediation appears to be capable of removing efficiently contaminants from the source area as well as the concentrated plume. Initial research was conducted on separate removal of trichloroethylene (TCE) and an oil. It was found that oil permeation and modified pervaporation are effective techniques of removing oil and TCE respectively from the simulated feed. It was found that the oil permeation technique can effectively remove 98-99% of oil from an oil-in-water emulsion. The subsurface-entrapped organic pollutants often have high boiling components along with the VOCs. A combined permeation technique is applied here to simultaneously remove TCE and n-dodecane …

Testing Statistical Significance In Sequence Classification Algorithms, Tom Tien-Hua Shih

Theses

Multiple sequence alignment has proven to be a successful method of representing and organizing of protein sequence data. It is crucial to medical researches on the structure and function of proteins.

There have been numerous tools published on how to abstract meaningful relationship from an unknown sequence and a set of known sequences. One study used a method for discovering active motifs in a set of related protein sequences. These are meaningful knowledge abstracted from the known protein database since most protein families are characterized by multiple local motifs. Another study abstracts knowledge regarding the input sequence using a preconstructed …

Soot Capture In An Electrocatalytic Reactor, Thana Slanvetpan

Theses

A major problem with many soot emission control devices is the fact that they quickly become loaded with soot which must be removed by a regeneration process. A soot capture reactor using a large flow channel was studied in order to eliminate channel plugging and avoid regeneration. Electrostatic precipitation was used in order to enhance particle diffusion to the catalyst wall of the reactor tube. The system effectiveness for soot capture was measured with filter paper sampling of the incoming versus the outgoing flow through the reactor. Soot filter loadings were analyzed by laser optical transmission. From the soot filter …