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Further studies of the effects of oxidation on the surface properties of coal and coal pyrite

Description: The objective of this research was to investigate the oxidation behavior of coal and coal pyrite and to correlate the changes in the surface properties induced by oxidation, along with the intrinsic physical and chemical properties of these organic and inorganic materials, with the behavior in physical coal cleaning processes. This provide more fundamental knowledge for understanding the way in which different factors interact in a medium as heterogeneous as coal. Fourteen coal samples of diffe… more
Date: December 31, 1994
Creator: Herrera, Miguel Nicholas
Partner: UNT Libraries Government Documents Department
open access

An analysis of monojet data in p{bar p} collisions at {radical}s = 1.8 TEV

Description: An analysis is presented of events with a single jet and significant missing transverse energy selected from 4.7 pb{sup {minus}1} of data collected at the Fermilab Tevatron with the CDF detector. The goal is to identify events of the type p{bar p} {yields} Z{sup 0} + jet; Z{sup 0} {yields} {nu}{bar {nu}}. Event selection and backgrounds are discussed. The number of observed monojet events is compared to the number of observed Z{sup 0} {yields} e{sup +}{sup {minus}} events in which the Z{sup 0} … more
Date: December 31, 1992
Creator: Markeloff, R.
Partner: UNT Libraries Government Documents Department
open access

A correlation between soil descriptions and {sup 226}Ra concentrations in Florida soils

Description: The soil radium content in Florida is highly variable. The range in radium concentrations, where the samples involved in this study are concerned, is from 0.1 pCi/g to 18.5 pCi/g. Low {sup 226}Ra concentrations (0.1 to 5 pCi/g) are evidenced in sands, moderate concentrations (5 to 11 pCi/g) are found in silt and gravel, and high {sup 226}Ra concentrations (>11 pCi/g) are found in soil horizons with shell, clay, and strata with phosphate. Strata containing phosphate yields a high concentration o… more
Date: December 31, 1992
Creator: Harrison, D. P.
Partner: UNT Libraries Government Documents Department
open access

Use of ligand-modified micellar-enhanced ultrafiltration to selectively separate copper ions from wastewater streams

Description: The selective removal of target ions from an aqueous solution containing ions of like charge by ligand-modified micellar-enhanced ultrafiltration (LM-MEUF), is presented. In LM-MEUF, surfactant and specially tailored ligand are added to the contaminated stream. The surfactant forms aggregates called micelles, the hydrocarbon core of which the ligand complexed with the target species will solubilize. The surfactant is chosen to have the same charge type as the target ion; therefore, other ions (… more
Date: December 31, 1992
Creator: Shadizadeh, S. B.
Partner: UNT Libraries Government Documents Department
open access

Mass and charge distributions in chlorine-induced nuclear reactions

Description: Projectile-like fragments were detected and characterized in terms of A, Z, and energy for the reactions {sup 37}Cl on {sup 40}Ca and {sup 209}Bi at E/A = 7.3 MeV, and {sup 35}Cl, on {sup 209}Bi at E/A = 15 MeV, at angles close to the grazing angle. Mass and charge distributions were generated in the N-Z plane as a function of energy loss, and have been parameterized in terms of their centroids, variances, and coefficients of correlation. Due to experimental problems, the mass resolution corres… more
Date: December 31, 1991
Creator: Marchetti, A. A.
Partner: UNT Libraries Government Documents Department
open access

A Fully Coupled Monte Carlo/Discrete Ordinates Solution to the Neutron Transport Equation. Final Report

Description: The neutron transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S{sub N}) and stochastic (Monte Carlo) methods are applied. Unlike previous hybrid methods, the Monte Carlo and S{sub N} regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid method provides a new means of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S{sub N}… more
Date: December 31, 1990
Creator: Filippone, W. L. & Baker, R. S.
Partner: UNT Libraries Government Documents Department
open access

Solubilization of pentanol by cationic surfactants and binary mixtures of cationic surfactants

Description: The research reported here has included studies of the solubilization of pentanol in hexadecylpyridinium chloride (CPC), trimethyletetradecylammonium chloride (C{sub 14}Cl), benzyldimethyltetradecylammonium chloride (C{sub 14}BzCl), benzyldimethylhexadecylpyridinium chloride (C{sub 16}BzCl), hexadecyltrimethylammonium bromide (CTAB), and binary mixtures of CPC + C{sub 16}BzCl and C{sub 14}Cl + C{sub 14}BzCl. Rather than using calorimetric methods, this project will employ headspace chromatograp… more
Date: December 31, 1993
Creator: Morgan, M. E.
Partner: UNT Libraries Government Documents Department
open access

Nonlinear self-focus of pulsed-wave beams in Kerr media

Description: A modified finite-difference time-domain method for solving Maxwell`s equations in nonlinear media is presented. This method allows for a finite response time to be incorporated in the medium, physically creating dispersion and absorption mechanisms. The technique models electromagnetic fields in two space dimensions and time and encompasses both the TE{sub z} and TM{sub z} set of decoupled field equations. Aspects of an ultra-short pulsed Gaussian beam are studied in a variety of linear and no… more
Date: December 31, 1992
Creator: Judkins, J. B.
Partner: UNT Libraries Government Documents Department
open access

Nuclear power plant status diagnostics using a neural network with dynamic node architecture

Description: This thesis is part of an ongoing project at Iowa State University to develop ANN based fault diagnostic systems to detect and classify operational transients at nuclear power plants. The project envisages the deployment of such an advisor at Iowa Electric Light and Power Company`s Duane Arnold Energy Center nuclear power plant located at Palo, IA. This advisor is expected to make status diagnosis in real time, thus providing the operators with more time for corrective measures.
Date: December 31, 1992
Creator: Basu, A.
Partner: UNT Libraries Government Documents Department
open access

A study of the ability of the D0 detector to measure the single jet inclusive cross section

Description: The D0 experiment began accumulating data at the Fermilab Tevatron in May of 1992. Protons are collided with antiprotons at {radical}s = 1.8 TeV and an expected peak luminosity of 5 {times} 10{sup 30} cm{sup {minus}2} sec{sup {minus}1}. The D0 detector is an all-purpose detector that will have exceptional jet reconstruction capabilities derived from superior calorimetry and nearly 4{pi} angular coverage. One of the many physics measurements that will be made at D0 is the inclusive jet cross sec… more
Date: December 31, 1992
Creator: Astur, R. V.
Partner: UNT Libraries Government Documents Department
open access

A search for first generation scalar leptoquarks at {radical}s = 1.8 TeV with the D0 detector

Description: A search for first generation scalar leptoquarks was done at the DO detector at Fermi National Accelerator Laboratory from 15 pb{minus}1 of data taken during the 1992--1993 colder run. At Fermilab`s p{bar p} collider with a center-of-mass energy of 1.8 TeV, leptoquarks are produced mostly by the strong force in pairs. Leptoquarks carry fractional charge, color, and also lepton and baryon quantum numbers. First generation leptoquarks couple exclusively to the electron, electron neutrino, and the… more
Date: December 31, 1993
Creator: Norman, D. M.
Partner: UNT Libraries Government Documents Department
open access

The parallel implementation of a backpropagation neural network and its applicability to SPECT image reconstruction

Description: The objective of this study was to determine the feasibility of using an Artificial Neural Network (ANN), in particular a backpropagation ANN, to improve the speed and quality of the reconstruction of three-dimensional SPECT (single photon emission computed tomography) images. In addition, since the processing elements (PE)s in each layer of an ANN are independent of each other, the speed and efficiency of the neural network architecture could be better optimized by implementing the ANN on a ma… more
Date: December 31, 1992
Creator: Kerr, J. P.
Partner: UNT Libraries Government Documents Department
open access

An equilibrium model for ligand-modified micellar-enhanced ultrafiltration, selective separation of metal ions using iminoacetic substituted polyamines and a theoretical model for the titration behavior of polyamines

Description: This thesis consists of three chapters. Chapter 1, An equilibrium model for ligand-modified micellar-enhanced ultrafiltration, describes a theoretical model and experimental investigations which used the semi-equilibrium-dialysis method with N-n-dodecyl iminodiacetic acid as the ligand. In Chapter 2, Selective separation of metal ions using iminoacetic substituted polyamines, polyamines with a substituted ligand group are synthesized and used in investigating selective separation of copper ions… more
Date: December 31, 1992
Creator: Dharmawardana, U. R.
Partner: UNT Libraries Government Documents Department
open access

A measurement of the e/{pi} ratio difference between short (250 ns) and long (2.2 {mu}s) integration times with the D0 uranium-liquid argon central calorimeter

Description: The difference of the ratios of the high energy electron and pion responses(e/{pi}) in the DO Uranium-liquid Argon central calorimeter is measured using the DO calorimeter trigger readout (short integration time: 250 ns) and precision readout (long integration time: 2.2 {mu}s). This measurement found a 5% difference in the e/{pi} ratio between short and long integration times, with estimated uncertainty of 2.3%.
Date: December 31, 1992
Creator: Pi, B.
Partner: UNT Libraries Government Documents Department
open access

The importance of input variables to a neural network fault-diagnostic system for nuclear power plants

Description: This thesis explores safety enhancement for nuclear power plants. Emergency response systems currently in use depend mainly on automatic systems engaging when certain parameters go beyond a pre-specified safety limit. Often times the operator has little or no opportunity to react since a fast scram signal shuts down the reactor smoothly and efficiently. These accidents are of interest to technical support personnel since examining the conditions that gave rise to these situations help determine… more
Date: December 31, 1992
Creator: Lanc, T. L.
Partner: UNT Libraries Government Documents Department
open access

The use of micellar solutions for novel separation techniques

Description: Surfactant based separation techniques based on the solubilization of organic compounds into the nonpolar interior of a micelle or electrostatic attraction of ionized metals and metal complexes to the charged surface of a micelle were studied in this work. Micellar solutions were used to recover two model volatile organic compounds emitted by the printing and painting industries (toluene and amyl acetate) and to investigate the effect of the most important variables in the surfactant enhanced c… more
Date: December 31, 1993
Creator: Roberts, B. L.
Partner: UNT Libraries Government Documents Department
open access

MagRad: A code to optimize the operation of superconducting magnets in a radiation environment

Description: A powerful computational tool, called MagRad, has been developed which optimizes magnet design for operation in radiation fields. Specifically, MagRad has been used for the analysis and design modification of the cable-in-conduit conductors of the TF magnet systems in fusion reactor designs. Since the TF magnets must operate in a radiation environment which damages the material components of the conductor and degrades their performance, the optimization of conductor design must account not only… more
Date: December 31, 1995
Creator: Yeaw, Christopher T.
Partner: UNT Libraries Government Documents Department
open access

Probabilistic assessment of dynamic system performance. Part 3

Description: Accurate prediction of dynamic system failure behavior can be important for the reliability and risk analyses of nuclear power plants, as well as for their backfitting to satisfy given constraints on overall system reliability, or optimization of system performance. Global analysis of dynamic systems through investigating the variations in the structure of the attractors of the system and the domains of attraction of these attractors as a function of the system parameters is also important for … more
Date: December 31, 1993
Creator: Belhadj, M.
Partner: UNT Libraries Government Documents Department
open access

Phenomenological and mathematical modeling of a high pressure steam driven jet injector. Part 2

Description: An injector is a particular type of jet pump which uses condensable vapor to entrain a liquid and discharge against a pressure higher than either motive or suction pressures. The injector has no moving parts and requires no external power supply nor any complex control system. Thus, the injector is particularly suited for emergency core cooling operations. A detailed survey has indicated that various injector designs are available for operating pressures below 250 psig. However, the design of t… more
Date: December 31, 1993
Creator: Anand, G.
Partner: UNT Libraries Government Documents Department
open access

A Compton scatter camera for spectral imaging of 0.5 to 3.0 MeV gamma rays

Description: A prototype Compton scatter camera for imaging gamma rays has been built and tested. This camera addresses unique aspects of gamma-ray imaging at nuclear industrial sites, including gamma-ray energies in the 0.5 to 3.0 MeV range and polychromatic fields. Analytic models of camera efficiency, resolution and contaminating events are developed. The response of the camera bears strong similarity to emission computed tomography devices used in nuclear medicine. A direct Fourier based algorithm is de… more
Date: December 31, 1994
Creator: Martin, J.B.
Partner: UNT Libraries Government Documents Department
open access

A study of radon-222 concentrations in North Carolina groundwater

Description: The groundwater of 400 North Carolina homes was sampled to ascertain the distribution and extent of {sup 222}Rn in North Carolina groundwater. Arithmetic mean (AM) and geometric mean (GM) concentrations of 1,816 pCi L{sup {minus}1} and 656 pCi L{sup {minus}1} were found for the state. These results indicate that two-thirds of 114{degree}C. homes served by groundwater exceed the EPA proposed 300 pCi L{sup {minus}1} maximum contaminant level (MCL). Only 2% of NC homes exceeded 10,000 pCi L-1. The… more
Date: December 31, 1992
Creator: Evans, J. P.
Partner: UNT Libraries Government Documents Department
open access

Direct {anti b}b production in {anti p}p collisions at {radical}s = 1.8 TeV

Description: The first measurement of bottom quark production in the forward detector at CDF is presented in this thesis. Events from the 1988/89 Fermilab collider run were selected with forward muons with nearby jets to form a bottom quark tag. The efficiency and acceptance of the detector are then taken into account and the number of events is turned into a cross section: {sigma}(p{sub t}{sup b} > 20 GeV, 1.9 < {vert_bar}{eta}{sup b}{vert_bar} < 2.5) = (124. {+-} 35. {+-} 76.) nb. The contribution from di… more
Date: December 31, 1993
Creator: Lamoureux, J.
Partner: UNT Libraries Government Documents Department
open access

Ion sensitive field effect transistors applied to the measurement of the pH of brines

Description: The ability to measure the pH (the negative logarithm of the hydrogen ion activity) of harsh fluids such as geothermal oil field brines is important, since pH is a fundamental property; as one chemist stated: ``very often pH is a critical test because its accuracy lays the foundation for other measurements``. In our research, we focus on the analysis of brines similar to those found in underground geothermal reservoirs. Since the brines are deep under the ground, the values of the pressure and … more
Date: December 31, 1991
Creator: Chen, J.
Partner: UNT Libraries Government Documents Department
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