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

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

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} is accompanied by a jet. We measure the number of light neutrino species to be N{sub {nu}} = 2.2{plus_minus}1.5 and we place an upper limit on the number of neutrino species at N{sub {nu}} < 5 (90% C.L.).
Date: December 31, 1992
Creator: Markeloff, R.
System: The UNT Digital Library
An artificial neutral network fault-diagnostic adviser for a nuclear power plant with error prediction (open access)

An artificial neutral network fault-diagnostic adviser for a nuclear power plant with error prediction

This thesis is part of an ongoing project at Iowa State University to develop ANN bases fault diagnostic systems to detect and classify operational transients at nuclear power plants.
Date: December 31, 1992
Creator: Kim, Keehoon
System: The UNT Digital Library
A correlation between soil descriptions and {sup 226}Ra concentrations in Florida soils (open access)

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

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 of {sup 226}Ra. The information obtained in this study, soil descriptions with their corresponding {sup 226}Ra concentrations, comes from geological cores drilled by geotechnical consultants with gamma spectrometry analysis performed by high resolution gamma spectroscopy. Concentration; of {sup 226}Ra generally increase with depth. These cores are usually terminated at 20 feet deep, with some cores being shallower than this due to hitting bedrock or encountering the water table. These frequency distributions give the core-logging geologist an approximate concentration of {sup 226}Ra based on the description of the soil. Since the correlation of {sup 226}Ra and soil descriptions can be used as a tool in assigning indoor radon potential, this study is of importance to land managers, contractors, developers, and regulating …
Date: December 31, 1992
Creator: Harrison, D. P.
System: The UNT Digital Library
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 (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

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 from aqueous solution. In Chapter 3, A theoretical model for the titration behavior of polyamines, a novel approach to explain the titration behavior of polymeric amines based on the binding behavior of counterions is described. The application of this study is to the investigation of inexpensive and efficient methods of industrial waste water treatment.
Date: December 31, 1992
Creator: Dharmawardana, U. R.
System: The UNT Digital Library
Growth, life history, and species interactions of bluegill sunfish (Lepomis macrochirus) under heavy predation (open access)

Growth, life history, and species interactions of bluegill sunfish (Lepomis macrochirus) under heavy predation

The purpose of this study was, first, to compare growth and life history characteristics of an unfished population of bluegill sunfish (Lepomis macrochirus) in the presence of an abundant predator population to characteristic exhibited by bluegills in typical southeastern US reservoirs where the abundance of predators is reduced, but fishing is increased. The second objective was to determine if differences observed between populations were determined genetically or environmentally.
Date: December 31, 1992
Creator: Belk, M. C.
System: The UNT Digital Library
The importance of input variables to a neural network fault-diagnostic system for nuclear power plants (open access)

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

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 causality. In many other cases an automated fault-diagnostic advisor would be a valuable tool in assisting the technicians and operators to determine what just happened and why.
Date: December 31, 1992
Creator: Lanc, T. L.
System: The UNT Digital Library
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 (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

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.
System: The UNT Digital Library
A measurement of the forward-backward asymmetry and sin{sup 2}{theta}{sub W} from the process Z{sup 0} {yields} {mu}{sup +}{mu}{sup {minus}} at {radical}s = 1.8 TeV (open access)

A measurement of the forward-backward asymmetry and sin{sup 2}{theta}{sub W} from the process Z{sup 0} {yields} {mu}{sup +}{mu}{sup {minus}} at {radical}s = 1.8 TeV

A measurement of the forward-backward charge asymmetry in the decay of Z{sup o} bosons produced from {bar p}p collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron collider, and decaying to {mu}{sup +} {mu}{sup {minus}} pairs is presented. From this asymmetry, a value for the Weinburg angle, sin{sup 2} {theta}{sub W}, is extracted and compared to values from other experiments.
Date: December 31, 1992
Creator: Markosky, L. A.
System: The UNT Digital Library
Nonlinear self-focus of pulsed-wave beams in Kerr media (open access)

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

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 nonlinear environments to demonstrate that the methods developed here can be used efficaciously in the modeling of pulses in complex problem space geometries even when nonlinearities are present.
Date: December 31, 1992
Creator: Judkins, J. B.
System: The UNT Digital Library
Nuclear power plant status diagnostics using a neural network with dynamic node architecture (open access)

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

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.
System: The UNT Digital Library
The parallel implementation of a backpropagation neural network and its applicability to SPECT image reconstruction (open access)

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

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 massively parallel computer. The specific goals of this research were: to implement a fully interconnected backpropagation neural network on a serial computer and a SIMD parallel computer, to identify any reduction in the time required to train these networks on the parallel machine versus the serial machine, to determine if these neural networks can learn to recognize SPECT data by training them on a section of an actual SPECT image, and to determine from the knowledge obtained in this research if full SPECT image reconstruction by an ANN implemented on a parallel computer is feasible both in time required to train the network, and in quality of the images reconstructed.
Date: December 31, 1992
Creator: Kerr, J. P.
System: The UNT Digital Library
A study of radon-222 concentrations in North Carolina groundwater (open access)

A study of radon-222 concentrations in North Carolina groundwater

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 Eastern region had the lowest radon concentrations by far, with a GM of 2-)0 pCi L{sup {minus}1}. The Central region and Western region had GM`s of 794 pCi L{sup {minus}1} and 1,032 pCi L{sup {minus}1} respectively. The groundwater data approached a log normal distribution. No consistent trends were noted in the relationship between indoor radon concentrations and groundwater radon concentrations. A correlation coefficient of 0.00921 revealed a very weak linear relationship.
Date: December 31, 1992
Creator: Evans, J. P.
System: The UNT Digital Library
A study of the ability of the D0 detector to measure the single jet inclusive cross section (open access)

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

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 section. Comparison of this cross section with theoretical predictions allows us to test the accuracy of the standard model of Quantum Chromodynamics (QCD). This comparison is usually in the form of a measurement of the differential cross section with respect to the transverse energy of the jet. The extended angular coverage of the D0 detector allows measurements of the differential cross section as a function of jet rapidity as well. Recently completed calculations of the next-to-leading-order contribution to the inclusive cross section result in predictions with reduced theoretical errors. In addition, recent fits to data from deep inelastic scattering and single photon experiments further restrict the quark and gluon structure functions of the proton which are necessary in the theoretical predictions of …
Date: December 31, 1992
Creator: Astur, R. V.
System: The UNT Digital Library
Use of ligand-modified micellar-enhanced ultrafiltration to selectively separate copper ions from wastewater streams (open access)

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

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 (with similar charge) will not associate with the micelle, which makes the separation of the target ion selective. The solution is then processed by ultrafiltration, using a membrane with pore size small enough to block the passage of the micelles. In this study the divalent copper is the target ion in the solution containing divalent calcium. The surfactant is cetylpyridinium chloride (CPC) and the ligand is 4-hexadecyloxybenzyliminodiacetic acid (C{sub 16}BIDA). Experiments were conducted with batch stirred cells and the results have been compared to separation that take place under a variety of conditions in the LM-MEUF process. Rejections of copper of up to 99.8% are observed, with almost no rejection of calcium, showing that LM-MEUF has excellent selectivity and separation efficiency.
Date: December 31, 1992
Creator: Shadizadeh, S. B.
System: The UNT Digital Library