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Level Curves of the Angle Function of a Positive Definite Symmetric Matrix (open access)

Level Curves of the Angle Function of a Positive Definite Symmetric Matrix

Given a real N by N matrix A, write p(A) for the maximum angle by which A rotates any unit vector. Suppose that A and B are positive definite symmetric (PDS) N by N matrices. Then their Jordan product {A, B} := AB + BA is also symmetric, but not necessarily positive definite. If p(A) + p(B) is obtuse, then there exists a special orthogonal matrix S such that {A, SBS^(-1)} is indefinite. Of course, if A and B commute, then {A, B} is positive definite. Our work grows from the following question: if A and B are commuting positive definite symmetric matrices such that p(A) + p(B) is obtuse, what is the minimal p(S) such that {A, SBS^(-1)} indefinite? In this dissertation we will describe the level curves of the angle function mapping a unit vector x to the angle between x and Ax for a 3 by 3 PDS matrix A, and discuss their interaction with those of a second such matrix.
Date: December 2009
Creator: Bajracharya, Neeraj
System: The UNT Digital Library
An Evaluation of the Effects of Two Different Role Play Formats on the Outcomes of a Parent Training Curriculum (open access)

An Evaluation of the Effects of Two Different Role Play Formats on the Outcomes of a Parent Training Curriculum

The current study was designed to replicate and extend previous research on the effectiveness of behavioral parent training. Specifically, the effectiveness of the Behavior Management and Parenting Services (BMAPS) curriculum in teaching parents to exhibit a set of parenting skills and respond accurately to a multiple choice examination about positive parenting techniques was evaluated. In addition, the curriculum was revised so that the relative effectiveness and acceptability of two role play formats could be assessed. The outcomes of the study showed an improvement in the participants' ability to identify correct answers on a multiple choice examination and apply the parenting skills taught in class within a role play format; results pertaining to the efficacy of each role play format were less conclusive.
Date: December 2009
Creator: Carlson Litscher, Barbara J.
System: The UNT Digital Library
Latent Transition Analysis of Pre-service Teachers' Efficacy in Mathematics and Science (open access)

Latent Transition Analysis of Pre-service Teachers' Efficacy in Mathematics and Science

This study modeled changes in pre-service teacher efficacy in mathematics and science over the course of the final year of teacher preparation using latent transition analysis (LTA), a longitudinal form of analysis that builds on two modeling traditions (latent class analysis (LCA) and auto-regressive modeling). Data were collected using the STEBI-B, MTEBI-r, and the ABNTMS instruments. The findings suggest that LTA is a viable technique for use in teacher efficacy research. Teacher efficacy is modeled as a construct with two dimensions: personal teaching efficacy (PTE) and outcome expectancy (OE). Findings suggest that the mathematics and science teaching efficacy (PTE) of pre-service teachers is a multi-class phenomena. The analyses revealed a four-class model of PTE at the beginning and end of the final year of teacher training. Results indicate that when pre-service teachers transition between classes, they tend to move from a lower efficacy class into a higher efficacy class. In addition, the findings suggest that time-varying variables (attitudes and beliefs) and time-invariant variables (previous coursework, previous experiences, and teacher perceptions) are statistically significant predictors of efficacy class membership. Further, analyses suggest that the measures used to assess outcome expectancy are not suitable for LCA and LTA procedures.
Date: December 2009
Creator: Ward, Elizabeth Kennedy
System: The UNT Digital Library
Fabrication and characterization of submicron polymer waveguides by micro-transfer molding (open access)

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
Precision measurement of the top quark mass in the lepton + jets channel using a matrix element method with Quasi-Monte Carlo integration (open access)

Precision measurement of the top quark mass in the lepton + jets channel using a matrix element method with Quasi-Monte Carlo integration

This thesis presents a measurement of the top quark mass obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. The measurement uses a matrix element integration method to calculate a t{bar t} likelihood, employing a Quasi-Monte Carlo integration, which enables us to take into account effects due to finite detector angular resolution and quark mass effects. We calculate a t{bar t} likelihood as a 2-D function of the top pole mass m{sub t} and {Delta}{sub JES}, where {Delta}{sub JES} parameterizes the uncertainty in our knowledge of the jet energy scale; it is a shift applied to all jet energies in units of the jet-dependent systematic error. By introducing {Delta}{sub JES} into the likelihood, we can use the information contained in W boson decays to constrain {Delta}{sub JES} and reduce error due to this uncertainty. We use a neural network discriminant to identify events likely to be background, and apply a cut on the peak value of individual event likelihoods to reduce the effect of badly reconstructed events. This measurement uses a total of 4.3 fb{sup -1} of integrated luminosity, requiring events with a lepton, large E{sub T}, and exactly four …
Date: December 1, 2009
Creator: Lujan, Paul Joseph & /UC, Berkeley /LBL, Berkeley
System: The UNT Digital Library
Wave propagation in photonic crystals and metamaterials: Surface waves, nonlinearity and chirality (open access)

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
X-ray resonant magnetic scattering investigations of hexagonal multiferroics RMnO3 (R = Dy, Ho, Er) (open access)

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 the Cross Section of Charmed Hadrons and the Nuclear Dependence Alpha (open access)

Measurement of the Cross Section of Charmed Hadrons and the Nuclear Dependence Alpha

With data from the SELEX experiment we study charm hadro-production. We report the differential production cross sections as function of the longitudinal and transverse momentum, as well as for two different target materials, of 14 charmed hadron and/or their decay modes. This is the most extensive study to date. SELEX is a fixed target experiment at Fermilab with high forward acceptance; it took data during 1996-1997 with 600 GeV/c {Sigma}{sup -} and {pi}{sup -}, and 540 GeV/c proton and {pi}{sup +} beams. It used 5 target foils (two copper and three diamond). We use the results to determine {alpha}, used in parametrizing the production cross section as {infinity} A{sup {alpha}}, where A is the mass number of the target nuclei. We found within our statistics that {alpha} is independent of the longitudinal momentum fraction x{sub F} in the interval 0.1 < x{sub F} < 1.0, with {alpha} = 0.778 {+-} 0.014. The average value of {alpha} for charm production by pion beams is {alpha}{sub meson} = 0.850 {+-} 0.028. This is somewhat larger than the corresponding average {alpha}{sub baryon} = 0.755 {+-} 0.016 for charm production by baryon beams ({Sigma}{sup -} and protons).
Date: December 1, 2009
Creator: Blanco-Covarrubias, E.Alejandro & U., /San Luis Potosi
System: The UNT Digital Library
Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE (open access)

Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE

The MiniBooNE experiment at the Fermi National Accelerator Laboratory (Fermilab) was designed to search for {nu}{sub {mu}} {yields} {nu}{sub e} neutrino oscillations at {Delta}m{sup 2} {approx} 1 eV{sup 2} using an intense neutrino flux with an average energy E{sub {nu}} {approx} 700 MeV. From 2002 to 2009 MiniBooNE has accumulated more than 1.0 x 10{sup 21} protons on target (POT) in both neutrino and antineutrino modes. MiniBooNE provides a perfect platform for detailed measurements of exclusive and semiinclusive neutrino cross-sections, for which MiniBooNE has the largest samples of events up to date, such as neutral current elastic (NCE), neutral current {pi}{sup 0}, charged current quasi-elastic (CCQE), charged current {pi}{sup +}, and other channels. These measured cross-sections, in turn, allow to improve the knowledge of nucleon structure. This thesis is devoted to the study of NCE interactions. Neutrino-nucleus neutral current elastic scattering ({nu}N {yields} {nu}N) accounts for about 18% of all neutrino interactions in MiniBooNE. Using a high-statistics, high purity sample of NCE interactions in MiniBooNE, the flux-averaged NCE differential cross-section has been measured and is being reported here. Further study of the NCE cross-section allowed for probing the structure of nuclei. The main interest in the NCE cross-section is that …
Date: December 1, 2009
Creator: Perevalov, Denis & U., /Alabama
System: The UNT Digital Library
Considering value of information when using CFD in design (open access)

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
Time Dependent Analysis of B to rho0rho0 Decays (open access)

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
Measurements of top quark pair production cross section in proton anti-proton collisions at s**(1/2) = 1.96 TeV in the tau + jets final state using 1 inv fb of data (open access)

Measurements of top quark pair production cross section in proton anti-proton collisions at s**(1/2) = 1.96 TeV in the tau + jets final state using 1 inv fb of data

This dissertation presents a new measurement of p{bar p} {yields} t{bar t}X production at {radical}s = 1.96 TeV using 974.2 pb{sup -1} of data collected with the D0 detector between 2002 and 2006. We focus on the final state where the W boson from one of the top quarks decays into a {tau} lepton and its associated neutrino, while the other W boson decays into a quark-antiquark pair. We aim to select those events in which the {tau} lepton subsequently decays hadronically, meaning to one or three charged hadrons, zero or more neutral hadrons and a tau neutrino (the charge conjugate processes are implied in all of the above). The observable signature thus consists of a narrow calorimeter shower with associated track(s) characteristic of a hadronic tau decay, four or more jets, of which two are initiated by b quarks accompanying the W's in the top quark decays, and a large net missing momentum in the transverse plane due to the energetic neutrino-antineutrino pair that leave no trace in the detector media. The preliminary result for the measured cross section is: {sigma}(t{bar t}) = 6.9{sub -1.2}{sup +1.2}(stat){sub -0.7}{sup +0.8}(syst) {+-} 0.4 (lumi) pb. This indicates that our finding is consistent …
Date: December 1, 2009
Creator: Hossain, Sohrab
System: The UNT Digital Library
Measurement of single top quark production in the tau+jets channnel using boosted decision trees at D0 (open access)

Measurement of single top quark production in the tau+jets channnel using boosted decision trees at D0

The top quark is the heaviest known matter particle and plays an important role in the Standard Model of particle physics. At hadron colliders, it is possible to produce single top quarks via the weak interaction. This allows a direct measurement of the CKM matrix element V{sub tb} and serves as a window to new physics. The first direct measurement of single top quark production with a tau lepton in the final state (the tau+jets channel) is presented in this thesis. The measurement uses 4.8 fb{sup -1} of Tevatron Run II data in p{bar p} collisions at {radical}s = 1.96 TeV acquired by the D0 experiment. After selecting a data sample and building a background model, the data and background model are in good agreement. A multivariate technique, boosted decision trees, is employed in discriminating the small single top quark signal from a large background. The expected sensitivity of the tau+jets channel in the Standard Model is 1.8 standard deviations. Using a Bayesian statistical approach, an upper limit on the cross section of single top quark production in the tau+jets channel is measured as 7.3 pb at 95% confidence level, and the cross section is measured as 3.4{sub -1.8}{sup +2.0} …
Date: December 1, 2009
Creator: Liu, Zhiyi & U., /Simon Fraser
System: The UNT Digital Library
Masters Thesis- Criticality Alarm System Design Guide with Accompanying Alarm System Development for the Radioisotope Production Laboratory in Richland, Washington (open access)

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
Evaluation of bisphenol E cyanate ester for the resin-injection repair of advanced composites (open access)

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
Measurement of D0 lifetime with the BaBar detector (open access)

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 (open access)

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
SQUID-Detected MRI in the Limit of Zero Static Field (open access)

SQUID-Detected MRI in the Limit of Zero Static Field

This thesis describes an implementation of the so-called&quot;zero-field MRI&quot; (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
A New Wireless Sensor Node Design for Program Isolation and Power Flexibility (open access)

A New Wireless Sensor Node Design for Program Isolation and Power Flexibility

Over-the-air programming systems for wireless sensor networks have drawbacks that stem from fundamental limitations in the hardware used in current sensor nodes. Also, advances in technology make it feasible to use capacitors as the sole energy storage mechanism for sensor nodes using energy harvesting, but most current designs require additional electronics. These two considerations led to the design of a new sensor node. A microcontroller was chosen that meets the Popek and Goldberg virtualization requirements. The hardware design for this new sensor node is presented, as well as a preliminary operating system. The prototypes are tested, and demonstrated to be sustainable with a capacitor and solar panel. The issue of capacitor leakage is considered and measured.
Date: December 2009
Creator: Skelton, Adam W.
System: The UNT Digital Library
Racial Stereotypes and Racial Assimilation in a Multiracial Society (open access)

Racial Stereotypes and Racial Assimilation in a Multiracial Society

Interest in a multiracial society has increased in recent years and including on racism and prejudice and in the propensity to stereotype out-groups. Theories on racism help explain the dominant group's prejudice toward subordinate groups. Yet they only explain why dominant group members stereotype subordinates or if the dominant group's propensity to stereotype is different from that of subordinate groups. Recent assimilation theories suggest that some minorities are assimilating with Whites but Blacks are not undergoing assimilation. Classic assimilation theory suggests that when a subordinate group assimilates with the dominant group then they will also take on the dominant group's values and beliefs, including their prejudices and propensities to stereotype. The use of racial stereotypes in support of the assimilation of a minority group has not been tested. Results from the LSAF national survey provide support for Asians to be assimilating with Whites. However, Hispanics do not appear to be taking on Whites' propensity to stereotype, contradicting the prediction that Hispanics are assimilating with Whites.
Date: December 2009
Creator: Youngblood, Thomas
System: The UNT Digital Library
CROSS SECTION MEASUREMENTS IN THE MAIN INJECTOR PARTICLE PRODUCTION (FNAL-E907) EXPERIMENT AT 58 GEV ENERGY (open access)

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
An Evaluation Model for Identifying Lewisville and San Angelo, Texas, as Senior Ready Communities (open access)

An Evaluation Model for Identifying Lewisville and San Angelo, Texas, as Senior Ready Communities

This research portrays a paradigm for the assessment of aging services to support populations aging in place. The dissertation was designed to establish a model to identify and evaluate senior ready communities. Area specific social programs and services are identified. In order to meet the growing needs of aging populations, the dynamic representation of existing services and the need for services that could be developed in certain communities require reevaluation in current planning, restructuring, and/or community development.
Date: December 2009
Creator: Sanders, David N.
System: The UNT Digital Library
An Investigation Into the Factors Leading to the Closure of 40 Private Four-Year Colleges between 1965 and 2005 (open access)

An Investigation Into the Factors Leading to the Closure of 40 Private Four-Year Colleges between 1965 and 2005

This study searches for a set of common indicators that contributed to the ultimate closure of 40 colleges and universities between 1965 and 2005. From research on related literature, a set of 31 contributing factors was identified by published experts and observers in higher education. That set of indicators was then used as a list of 31 questions answered by data found in newspaper articles, professional journals, published research work, published institutional records, data taken from the Department of Education, data taken from IPEDS, data published in historical recounts of the colleges of interest, etc. The data was accumulated in the form of yes/no responses to the 31 questions. Although the study involved only 40 colleges and universities this population represents the majority of institutions that pass the restrictions of limitations and delimitations described in the full document. The complete data set was processed using SPSS which produced ANOVA tables and level of statistical significance for each indicator question. The results indicate that out of the 31 original indicator questions there were two groups of statistically significant indicators. The larger group of indicators having statistical significance at the .05 level encompassed the smaller group having statistical significance at the .001 …
Date: December 2009
Creator: Province, Terry Paul
System: The UNT Digital Library
Health Status and Access Disparities Among the Uninsured Working-Age Population in a Safety-Net Healthcare Network in Tarrant County, Texas (open access)

Health Status and Access Disparities Among the Uninsured Working-Age Population in a Safety-Net Healthcare Network in Tarrant County, Texas

The objective of this research was to determine if healthcare access disparities exist across race and gender in a publically funded safety-net healthcare system in Texas. Data were examined from a representative random sample of 1468 adults aged 18-64 who were patients in this safety-net system in July and August of 2000 and were analyzed using binary logistic regression and chi-square measures of significance. Major Findings: On measures of health status - overall health rating (p =.051), limited employment (p =.000), energy level (p =.001), and worry (p =.012) - Anglos reported the worst health; Mexican Americans, the best health; with African Americans intermediate. Mexican Americans were more likely to have never had health insurance, and to also have had insurance in the past year; Anglos were least likely to have ever had insurance (p =.015) or to have had insurance in the past year (p =.000). On use of EDs (p =.028), problems getting prescription medicines (p =.029), and foregoing other necessities of life to pay for healthcare, Mexican Americans were least disadvantaged with African Americans reporting greatest use of EDs among both men and women, and Anglos the most problems with prescription medicines and foregoing care, especially among …
Date: December 2009
Creator: Queen, Courtney M.
System: The UNT Digital Library