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Cold Fusion Production and Decay of Neutron-Deficient Isotopes of Dubnium and Development of Extraction Systems for Group V Elements

Description: Excitation functions for the 1n and 2n exit channels of the 208Pb(51V,xn)259-xDb reaction were measured. A maximum cross section of the 1n exit channel of 2070+1100/-760 pb was measured at an excitation energy of 16.0 +- 1.8 MeV. For the 2n exit channel, a maximum cross section of 1660+450/-370 pb was measured at 22.0 +- 1.8 MeV excitation energy. The 1n excitation function for the 209Bi(50Ti,n)258Db reaction was remeasured, resulting in a cross section of 5480+1730/1370 pb at an excitation ene… more
Date: July 31, 2008
Creator: Gates, Jacklyn M.
Partner: UNT Libraries Government Documents Department
open access

Seismic velocity estimation from time migration

Description: This is concerned with imaging and wave propagation in nonhomogeneous media, and includes a collection of computational techniques, such as level set methods with material transport, Dijkstra-like Hamilton-Jacobi solvers for first arrival Eikonal equations and techniques for data smoothing. The theoretical components include aspects of seismic ray theory, and the results rely on careful comparison with experiment and incorporation as input into large production-style geophysical processing code… more
Date: May 31, 2007
Creator: Cameron, Maria Kourkina
Partner: UNT Libraries Government Documents Department
open access

The ^2H(e,e'p)n Reaction at High Four-Momentum Transfer

Description: This dissertation presents the highest four-momentum transfer, Q^2,quasielastic (x_Bj = 1) results from Experiment E01-020 which systematically explored the 2He(e,e'p)n reaction ("Electro-disintegration" of the deuteron) at three different four-momentum transfers, Q^2 = 0.8, 2.1, and 3.5 GeV^2 and missing momenta, P_miss = 0, 100, 200, 300, 400, and 500 GeV including separations of the longitudinal-transverse interference response function, R_LT, and extractoin of the longitudinal-transverse as… more
Date: December 31, 2006
Creator: Ibrahim, Hassan
Partner: UNT Libraries Government Documents Department
open access

Advanced Branching Control and Characterization of Inorganic Semiconducting Nanocrystals

Description: The ability to finely tune the size and shape of inorganic semiconducting nanocrystals is an area of great interest, as the more control one has, the more applications will be possible for their use. The first two basic shapes develped in nanocrystals were the sphere and the anistropic nanorod. the II_VI materials being used such as Cadmium Selenide (CdSe) and Cadmium Telluride (CdTe), exhibit polytypism, which allows them to form in either the hexagonally packed wurtzite or cubically packed zi… more
Date: December 31, 2007
Creator: Hughes, Steven Michael
Partner: UNT Libraries Government Documents Department
open access

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

Investigation of high-precision {Lambda} hypernuclear spectroscopy via the (e,e'K{sup +}) reaction

Description: The study of {Lambda} hypernuclear structure is very interesting in point of the understanding of the interaction between {Lambda} and nucleon ({Lambda}-N interaction) and its ”strange” structure itself due to the containment of a {Lambda} hyperon which has a strangeness as a new degree of freedom. In the several way to study the Lamda hypernuclei, the (e,e'K{sup +}) reaction spectroscopy is a powerful tool for the precise investigation of {Lamda} hypernuclear structure. The purpose of the… more
Date: March 31, 2012
Creator: Kawama, Daisuke
Partner: UNT Libraries Government Documents Department
open access

Probing Novel Properties of Nucleons and Nuclei via Parity Violating Electron Scattering

Description: This thesis reports on two experiments conducted by the HAPPEx (Hall A Proton Parity Experiment) collaboration at the Thomas Je#11;erson National Accelerator Facil- ity. For both, the weak neutral current interaction (WNC, mediated by the Z{sup 0} boson) is used to probe novel properties of hadronic targets. The WNC interaction amplitude is extracted by measuring the parity-violating asymmetry in the elastic scattering of longitudinally polarized electrons o#11; unpolarized target hadrons. HAPP… more
Date: May 31, 2012
Creator: Mercado, Luis
Partner: UNT Libraries Government Documents Department
open access

Compensation Techniques in Accelerator Physics

Description: Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along w… more
Date: May 31, 2011
Creator: Sayed, Hisham Kamal
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
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