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Masters Thesis- Criticality Alarm System Design Guide with Accompanying Alarm System Development for the Radioisotope Production Laboratory in Richland, Washington
A detailed instructional manual was created to guide criticality safety engineers through the process of designing a criticality alarm system (CAS) for Department of Energy (DOE) hazard class 1 and 2 facilities. Regulatory and technical requirements were both addressed. A list of design tasks and technical subtasks are thoroughly analyzed to provide concise direction for how to complete the analysis. An example of the application of the design methodology, the Criticality Alarm System developed for the Radioisotope Production Laboratory (RPL) of Richland, Washington is also included. The analysis for RPL utilizes the Monte Carlo code MCNP5 for establishing detector coverage in the facility. Significant improvements to the existing CAS were made that increase the reliability, transparency, and coverage of the system.
Date:
December 20, 2009
Creator:
Greenfield, Bryce A.
System:
The UNT Digital Library
Considering value of information when using CFD in design
This thesis presents an approach to find lower resolution CFD models that can accurately lead a designer to a correct decision at a lower computational cost. High-fidelity CFD models often contain too much information and come at a higher computational cost, limiting the designs a designer can test and how much optimization can be performed on the design. Lower model resolution is commonly used to reduce computational time. However there are no clear guidelines on how much model accuracy is required. Instead experience and intuition are used to select an appropriate lower resolution model. This thesis presents an alternative to this ad hoc method by considering the added value of the addition information provided by increasing accurate and more computationally expensive models.
Date:
December 19, 2009
Creator:
Misra, John Satprim
System:
The UNT Digital Library
Evaluation of bisphenol E cyanate ester for the resin-injection repair of advanced composites
This thesis is a compilation of a general introduction and literature review that ties together the subsequent chapters which consist of two journal articles that have yet to be submitted for publication. The overall topic relates to the evaluation and application of a new class of cyanate ester resin with unique properties that lend it applicable to use as a resin for injection repair of high glass transition temperature polymer matrix composites. The first article (Chapter 2) details the evaluation and optimization of adhesive properties of this cyanate ester and alumina nanocomposites under different conditions. The second article (Chapter 3) describes the development and evaluation of an injection repair system for repairing delaminations in polymer matrix composites.
Date:
December 19, 2009
Creator:
Lio, Wilber Yaote
System:
The UNT Digital Library
X-ray resonant magnetic scattering investigations of hexagonal multiferroics RMnO3 (R = Dy, Ho, Er)
Electricity and magnetism were unified into a common subject by James Clerk Maxwell in the nineteenth century yielding the electromagnetic theory. Four equations govern the dynamics of electric charges and magnetic fields, commonly known as Maxwell's equations. Maxwell's equations demonstrate that an accelerated charged particle can produce magnetic fields and a time varying magnetic field can induce a voltage - thereby linking the two phenomena. However, in solids, electric and magnetic ordering are most often considered separately and usually with good reason: the electric charges of electrons and ions are responsible for the charge effects, whereas the electron spin governs magnetic properties.
Date:
December 19, 2009
Creator:
Nandi, Shibabrata
System:
The UNT Digital Library
Measurement of D0 lifetime with the BaBar detector
This work is the result of the researchers carried out during a three years Ph.D. period in the BABAR experiment. The first chapter consists in an introduction to the theoretical aspects of the D{sup 0} meson lifetime determination and CP violation parameters, as well as an overview of the CP violation in the B sector, which is the main topic of the experiment. The description of the experimental apparatus follows with particular attention to the Silicon Vertex Tracker detector, the most critical detector for the determination of decay vertices and thus of lifetimes and time dependent CP violation asymmetries. In the fourth chapter the operation and running of the vertex detector is described, as a result from the experience as Operation Manager of the SVT, with particular attention to the safety of the device and the data quality assurance. The last chapter is dedicated to the determination of the D{sup 0} meson lifetime with the BABAR detector, which is the main data analysis carried out by the candidate. The analysis is characterized by the selection of an extremely pure sample of D{sup 0} mesons for which the decay flight length and proper time is reconstructed. The description of the unbinned …
Date:
December 17, 2009
Creator:
Simi, Gabriele & /SLAC, /Pisa U.
System:
The UNT Digital Library
Measurement of the B-bar 0 to D^* l ^- nu-bar Branching Fraction with a Partial Reconstruction Technique
Presented is a precise measurement of the {bar B}{sup 0} {yields} D*{sup +}{ell}{sup -}{bar {nu}}{sub {ell}} branching fraction using 81.47 fb{sup -1} of data collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at the Stanford Linear Accelerator Center. The measurement was performed by partially reconstructing the D*{sup +} meson from {bar B}{sup 0} {yields} D*{sup +}{ell}{sup -}{bar {nu}}{sub {ell}} decays using only the soft pion of the D*{sup +} {yields} D{sup 0}{pi}{sup +} decay to reconstruct its four vector. The branching fraction was measured to be {Beta}({bar B}{sup 0} {yields} D*{sup +}{ell}{sup -}{bar {nu}}{sub {ell}}) = (4.91 {+-} 0.01{sub stat} {+-} 0.15{sub syst})%.
Date:
December 17, 2009
Creator:
Sonnek, Peter & U., /Mississippi
System:
The UNT Digital Library
Fabrication and characterization of submicron polymer waveguides by micro-transfer molding
Various methods exist for fabrication of micron and submicron sized waveguide structures. However, most of them include expensive and time consuming semiconductor fabrication techniques. An economical method for fabricating waveguide structures is introduced and demonstrated in this thesis. This method is established based on previously well-developed photonic crystal fabrication method called two-polymer microtransfer molding. The waveguide in this work functions by a coupler structure that diffracts the incident light into submicron polymer rods. The light is then guided through the rods. Characterization is done by collecting the light that has been guided through the waveguide and exits the end of these submicron polymer bars. The coupling and waveguiding capabilities are demonstrated using two light sources, a laser and white light.
Date:
December 15, 2009
Creator:
Wu, Te-Wei
System:
The UNT Digital Library
SQUID-Detected MRI in the Limit of Zero Static Field
This thesis describes an implementation of the so-called"zero-field MRI" (ZFMRI) pulse sequence, which allows for imaging in an arbitrarily low B<sub>0</sub> field. The ZFMRI sequence created an effective unidirectional gradient field by using a train of pi pulses to average out the concomitant gradient components during encoding. The signals were acquired using a low-transition temperature dc Superconducting QUantum Interference Device (low-Tc dc SQUID) coupled to a first-order axial gradiometer. The experiments were carried out in a liquid helium dewar which was magnetically shielded with a single-layer mu-metal can around the outside and a superconducting Pb can contained within the helium space. We increased the filling factor of the custom-made, double-walled Pyrex insert by placing the liquid alcohol sample, at a temperature of approximately -50 degrees C, at the center of one loop of the superconducting gradiometer, which was immersed in the helium bath.
Date:
December 14, 2009
Creator:
Kelso, Nathan Dean
System:
The UNT Digital Library
Time Dependent Analysis of B to rho0rho0 Decays
The BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider is located at the Stanford Linear Accelerator Center. It has been gathering data on the {Upsilon}(4S) resonance from 2000 until 2007 with the primary objective of studying CP violation in B-meson decays. In this thesis they provide a theoretical overview of how CP violation arises in the context of the Standard Model, why B decays are relevant, and how BABAR gathers the necessary data. Specifically, they present the analysis of B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} decays in a sample of 465 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B}. They measure the corresponding branching fraction {Beta} = (0.92 {+-} 0.32(stat.) {+-} 0.14(syst.)) x 10{sup -6} and the longitudinal polarization fraction f{sub L} = 0.75{sub -0.14}{sup +0.11}(stat.) {+-} 0.04(syst.). The evidence for the B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} signal has a significance of 3.1 standard deviations ({sigma}), when the systematic uncertainties are included. There is insufficient evidence for B decays into similar modes and the corresponding upper limits are determined to be {Beta}{sub {rho}{sup 0}f{sub 0}} < 0.34 x 10{sup -6}, {Beta}{sub f{sub 0}f{sub 0}} < 0.16 x 10{sup -6}, {Beta}{sub {rho}{sup 0}{pi}{sup +}{pi}{sup -}} < 8.7 x 10{sup …
Date:
December 11, 2009
Creator:
Osipenkov, Ilya Leonidovich
System:
The UNT Digital Library
Wave propagation in photonic crystals and metamaterials: Surface waves, nonlinearity and chirality
Photonic crystals and metamaterials, both composed of artificial structures, are two interesting areas in electromagnetism and optics. New phenomena in photonic crystals and metamaterials are being discovered, including some not found in natural materials. This thesis presents my research work in the two areas. Photonic crystals are periodically arranged artificial structures, mostly made from dielectric materials, with period on the same order of the wavelength of the working electromagnetic wave. The wave propagation in photonic crystals is determined by the Bragg scattering of the periodic structure. Photonic band-gaps can be present for a properly designed photonic crystal. Electromagnetic waves with frequency within the range of the band-gap are suppressed from propagating in the photonic crystal. With surface defects, a photonic crystal could support surface modes that are localized on the surface of the crystal, with mode frequencies within the band-gap. With line defects, a photonic crystal could allow the propagation of electromagnetic waves along the channels. The study of surface modes and waveguiding properties of a 2D photonic crystal will be presented in Chapter 1. Metamaterials are generally composed of artificial structures with sizes one order smaller than the wavelength and can be approximated as effective media. Effective macroscopic parameters …
Date:
December 3, 2009
Creator:
Wang, Bingnan
System:
The UNT Digital Library
African Refugee Parents' Involvement in Their Children's Schools: Barriers and Recommendations for Improvement
The purpose of this study was to examine involvement of African refugee parents in the education of their elementary school children. The setting of the study was Northern and Southern Texas. African refugee parents and their children's teachers completed written surveys and also participated in interviews. In the study's mixed-method design, quantitative measures provided data about parent involvement at home, parent involvement at school, frequency of parent-teacher contact, quality of parent-teacher relationship, parent endorsement of children's schools, and barriers to parent involvement. Qualitative data from the open-ended questions provided data on barriers and strategies to improve involvement. Sixty-one African refugee parents responded to the survey and also participated in an in-depth face-to-face or telephone interview. Twenty teacher participants responded to an online survey. Quantitative data gathered from the parent and teacher surveys were analyzed using frequency distributions and analyses of variance. Qualitative data were analyzed by summarizing and sorting information into different categories using Weft QDA, an open-source qualitative analysis software. From these data, I identified barriers to African refugee parent involvement in their children's schools, as well as challenges that teachers face as they try to involve African refugee parents. Results of analyses of variance revealed statistically significant differences …
Date:
December 2009
Creator:
Githembe, Purity Kanini
System:
The UNT Digital Library
Analysis of School Discipline with a Focus on Characteristics of Hispanic Adolescents with Learning Disabilities from a Low-Socioeconomic Area
The research reported herein examined the emotional and behavioral characteristics of adolescent Hispanic students with and without learning disabilities from a middle school in north central Texas. The data were based on all students enrolled at the campus (N = 986), but focused on 55 students of Hispanic descent with learning disabilities and 55 students without. The data accrued for this study utilized a school discipline database. In addition, a 43-item behavioral rating scale was completed on each student of the more focused group. Methods of data analysis were derived from descriptive statistics, one-way analysis of variance, and multiple regression measurements. The results indicate that Hispanic students with learning disabilities often exhibit more disruptive behaviors.
Date:
December 2009
Creator:
Garcia-Rodriguez, Gina D.
System:
The UNT Digital Library
An Analytical Model of the Determinants and Outcomes of Nation Branding
Nation as a brand represents the intangible assets of a country, encompassing various dimensions such as politics, economics, culture, history, and technology. However, much of extant work in nation branding has been limited to the empirical investigations of its positioning and implementation for specific countries, while other scholarly works in nation branding are conceptual. Various factors associated with nation branding are discussed in the literature, but there is no organizing mechanism to connect these factors to explore the dynamics underlying nation branding. To fill this gap, this dissertation attempts to identify the relevant factors underlying the deployment of nation branding, and to develop models to assess the association among these factors. Hunt and Morgan's resource advantage theory serves as the theoretical foundation of this dissertation's framework. After establishing panel data models that link the factors of building and developing the nation brand, the strategic implications of nation branding are discussed. Archival data were used for economic factors such as economic development, tourism, export, and inward foreign investment, and cultural, political, infrastructural, and geographical factors. The primary data were collected for qualitative factors perceived reputable brand and perceived reputable industry. The Anholt-GfK Roper's 2008 Nation Brands IndexSM was incorporated into the …
Date:
December 2009
Creator:
Sun, Qin
System:
The UNT Digital Library
An Analytical Study: Applying Hindemith's Tonal Theory to Niels Viggo Bentzon's Third Piano Sonata, Op. 44
Niels Viggo Bentzon (1919-2000) is the most significant composer in the post-Nielsen period of Danish piano music. Bentzon's Third Piano Sonata, Op.44 was composed in 1946 and is considered by Mark L. Lehmann to be one of the great piano sonatas of the twentieth century. Not only does this sonata reflect Hindemith's ideas, but it also reveals Bentzon's unique style that successively empowers his innovative features. By applying Hindemith's theory, this study offers a way of understanding this piece and demonstrates the relevance of Hindemith's theory as a tool for analyzing the sonata. Chapter 1 presents the significance of the study, the state of research, the purpose of the study, and method. Chapter 2 provides a theoretical analysis of Bentzon's Third Piano Sonata, Op. 44. With a discussion of each movement, this analytical chapter traces Hindemith's influences: Bentzon organizes the four movements with a clear formal structure, a mediant relationship between the first movement and the rest of the movements, and a motivic coherence of each movement. Also, this chapter demonstrates how Bentzon follows Hindemith's way of chord construction and harmonic progression. This chapter provides insight into Bentzon's original style that facilitates an understanding of the tonal organization of each …
Date:
December 2009
Creator:
Kim, Sun Hee
System:
The UNT Digital Library
Assessing Play Interests in Toddlers.
Play is a significant part of childhood. Typically developing children exhibit a wide range of interests within their play behavior, but children with autism do not. The purpose of this study was to design and implement an assessment tool that will capture the constellation of behaviors indicating play interests in young children. The Early Play Interests Assessment (EPIA) includes categories of play behavior and their components behaviors. Additionally, measures of child affect were built into the EPIA. All behaviors were observed under various environmental conditions. The results show that the EPIA was useful in observing toddlers' play behavior within behavioral categories and components and in assessing the interactions among these measures of play interests. The results are discussed in relation to the importance of creating observational systems to quantify play interests in typical and atypical children and for establishing a link between the information gathered in assessment and the planning and implementation of autism interventions.
Date:
December 2009
Creator:
Kodaka, Mitsuru
System:
The UNT Digital Library
Assessing the Stimulus Control of Observers.
The science of behavior analysis relies heavily on direct observation. Human observers are typically used to measure behavior in applied settings. Although the use of human observers is beneficial in many regards, it also presents challenges. Of primary concern is the extent to which the data generated by observers actually corresponds to the behavioral events of interest, and the implications this may have in terms of replication. This study assessed the effects that labels, definitions, and examples and non-examples of two different modalities had on observer accuracy, consistency, and agreement. Results showed that current practices in observer training may require refinement to ensure high observer accuracy, consistency, and agreement. Suggestions for how to improve the desired stimulus control of observers are provided.
Date:
December 2009
Creator:
Kuhn, Robin Merritt
System:
The UNT Digital Library
Bidirectional Effects Between Engaged Lifestyle and Cognition in Later Life: Exploring the Moderation Hypothesis for Personality Variables.
Longitudinal data (N = 263) was used to investigate the bidirectional relationship between engagement (engaged lifestyle activities) and cognition (crystallized & fluid intelligence). Extroversion and openness to experience were also tested as moderators of the relationship between engagement and cognition. Results showed that the relationship between engagement at Wave 1 and cognition at Wave 2 did not differ from the relationship between cognition at Wave 1 and engagement at Wave 2. Testing for moderation with regression indicated that neither extroversion nor openness was moderating the relationship between engagement and cognition in either direction. Structural equation models provided further summary evidence that the relationships among engagement at Wave 1, extroversion, openness, and cognition at Wave 2 were not strong. However, a strong limitation to these results was the measurement error associated with a new measure of engagement.
Date:
December 2009
Creator:
Starkweather, Jonathan
System:
The UNT Digital Library
The Captive Animal Activity Tracking System: A Systematic Method for the Continuous Evaluation of Captive Animal Welfare.
Optimal animal welfare has been a long-term goal for captive animal institutions. To measure welfare a definition and identification of elements that make up welfare need to be established. Further, a method to measure welfare's elements that can be implemented into staff's daily routine is necessary to establish baseline levels and track changes in welfare. The goal of the proposed captive animal activity tracking system is to allow for the measurement of each element of welfare quickly, while providing information regarding the animal's current state of welfare and how changes to the animal's environment affect welfare. The data show that this system is effective in revealing behavioral patterns and changes in behavior that occurred in response to environmental changes.
Date:
December 2009
Creator:
Kalafut, Kathryn Lynn
System:
The UNT Digital Library
A Catalog of Extinctions
The preface describes the construction of a book-length, interwoven sequence of poems. This type of sequence differs from other types of poetry collections in its use of an overarching narrative, repeated images, and recurring characters. Three interwoven sequences are used as examples of how to construct such a sequence.
Date:
December 2009
Creator:
Casey, Edward Anthony
System:
The UNT Digital Library
Chamber Music with Double Bass: A New Approach to Function and Pedagogy.
The first part of the paper states the problem of the double bass not being incorporated into the chamber music program at many universities and the resulting lack of skills that can only be developed through this discipline. The double bass is trying to catch up with the other string instruments as it has been historically ignored, misunderstood and not as developed musically and technically. The historical background and current state of research are being examined to understand why this problem occurred in the first place, noting the vast amount of chamber music repertoire that is unknown and identifying some important but underperformed works. Further the pedagogical benefits of playing chamber music are discussed in order to realize the vital importance of integrating the double bass into the curriculum at major universities. Specific examples from the four major style periods are discussed in detail to show the benefits of studying this repertoire. Finally an implementation process is suggested to help change the current state of chamber music neglect as it pertains to the double bass.
Date:
December 2009
Creator:
Raschen, Gudrun
System:
The UNT Digital Library
Children's Spiritual Development: Analysis of Program Practices and Recommendations for Early Childhood Professionals.
The purpose of this study was to determine the extent to which faith-based preschools promote spiritual development in preschoolers. The participants in the study were faith-based early childhood teachers and administrators from seven states. Early childhood professionals representing 11 Christian faith traditions completed written surveys or online surveys. A total of 201 faith-based educators completed the survey; 20 respondents participated in semi-structured interviews. The concurrent triangulation mixed-method design provided data on 8 program dimensions which support children's spiritual development: prayer, Bible literacy, worship, building character, service opportunities, assessment, parental involvement and context. I analyzed quantitative data using descriptive and inferential statistics. All items were examined using mean, standard deviation, frequency, and percentages. Qualitative data gathered from semi-structured interviews were coded and analyzed using NVivo8® qualitative analysis software (QSR International, Inc., Cambridge, MA, http://www.qsrinternational.com). From this data I identified the extent to which faith-based preschool programs support children's spiritual development through the practices of prayer, Bible literacy, worship, building character, service opportunities, assessment, parental involvement and context. Data analyses revealed statistically significant differences in faith-based teachers' hours of training in children's spiritual development across all program practice dimensions. A key finding of the study was that training in children's spiritual development …
Date:
December 2009
Creator:
Myers, Joyce Eady
System:
The UNT Digital Library
Comparing a discriminative stimulus procedure to a pairing procedure: Conditioning neutral social stimuli to function as conditioned reinforcers.
Social stimuli that function as reinforcers for most children generally do not function as reinforcers for children diagnosed with autism. These important social stimuli include smiles, head nods, thumb-ups, and okay signs. It should be an important goal of therapy for children with autism to condition these neutral social stimuli to function as reinforcers for children diagnosed with autism. There is empirical evidence to support both a pairing procedure (classical conditioning) and a discriminative stimulus procedure to condition neutral stimuli to function as reinforcers. However, there is no clear evidence as to the superiority of effectiveness for either procedure. Despite this most textbooks and curriculum guides for children with autism state only the pairing procedure to condition neutral stimuli to function as reinforcers. Recent studies suggest that the discriminative stimulus procedure may in fact be more effective in conditioning neutral stimuli to function as reinforcers for children diagnosed with autism. The present research is a further comparison of these two procedures. Results from one participant support recent findings that suggest the discriminative stimulus procedure is more effective in conditioning neutral stimuli to function as reinforcers. But the results from the other participant show no effects from either procedure, suggesting future …
Date:
December 2009
Creator:
Koelker, Rachel Lee
System:
The UNT Digital Library
Comparison of IKONOS Derived Vegetation Index and LiDAR Derived Canopy Height Model for Grassland Management.
Forest encroachment is understood to be the main reason for prairie grassland decline across the United States. In Texas and Oklahoma, juniper has been highlighted as particularly opportunistic. This study assesses the usefulness of three remote sensing techniques to aid in locating the areas of juniper encroachment for the LBJ Grasslands in Decatur, Texas. An object based classification was performed in eCognition and final accuracy assessments placed the overall accuracy at 94%, a significant improvement over traditional pixel based methods. Image biomass was estimated using normalized difference vegetation index (NDVI) for 1 meter resolution IKONOS winter images. A high correlation between the sum of NDVI for tree objects and field tree biomass was determined where R = 0.72, suggesting NDVI sum of a tree area is plausible. However, issues with NDVI saturation and regression produced unrealistically high biomass estimates for large NDVI. Canopy height model (CHM) derived from 3-5m LiDAR data did not perform as well. LiDAR typically used for digital elevation model (DEM) production was acquired for the CHM and produced correlations of R = 0.26. This suggests an inability for this particular dataset to identify juniper trees. When points that registered a tree height where correlated with field …
Date:
December 2009
Creator:
Parker, Gary
System:
The UNT Digital Library
CROSS SECTION MEASUREMENTS IN THE MAIN INJECTOR PARTICLE PRODUCTION (FNAL-E907) EXPERIMENT AT 58 GEV ENERGY
Cross-sections are presented for 58 GeV {pi}, K, and p on a wide range of nuclear targets. These cross-sections are essential for determining the neutrino flux in measurements of neutrino cross-sections and oscillations. The E907 Main Injector Particle Production (MIPP) experiment at Fermilab is a fixed target experiment for measuring hadronic particle production using primary 120 GeV/c protons and secondary {pi}, K, and p beams. The particle identification is made by dE/dx in a time projection chamber, and by time-of-flight, differential Cherenkov and ring imaging Cherenkov detectors, which together cover a wide range of momentum from 0.1 GeV/c up to 120 GeV/c. MIPP targets span the periodic table, from hydrogen to uranium, including beryllium and carbon. The MIPP has collected {approx} 0.26 x 10{sup 6} events of 58 GeV/c secondary particles produced by protons from the main injector striking a carbon target.
Date:
December 1, 2009
Creator:
Gunaydin, Yusuf Oguzhan
System:
The UNT Digital Library