Country

The use of democratic institutions as a strategy to legitimize authoritarian rule. (open access)

The use of democratic institutions as a strategy to legitimize authoritarian rule.

Numerous authoritarian states use institutions usually associated with democratic regimes like a constitution, elections, and a legislature. This seems to be counterintuitive. Authoritarian regimes should rather shrink away from democratic institutions. Elections can be won by the opposition and legislatures can make decisions against the interests of the ruler. So, why do autocratic regimes install institutions which limit their power and threaten their survival in office? Assuming actors behave rationally, one should expect authoritarian rulers only to introduce procedures working in their favor. This study looks at the effect of institutions in authoritarian regimes. The findings suggest that legislatures significantly lower the chances of regime breakdown in the long run. However, particularly in election years, authoritarian regimes are facing a higher likelihood of failure.
Date: May 2007
Creator: Michalik, Susanne
System: The UNT Digital Library
Who Benefits? The Effects of Foreign Aid and Foreign Direct Investment on Human Rights (open access)

Who Benefits? The Effects of Foreign Aid and Foreign Direct Investment on Human Rights

The global emphasis on human rights has generated a surge of studies into what causes regimes to abuse the basic rights of their citizens. Causes of abuse can be internal or external in nature, based on economics, politics or cultures. This study examines the effects of foreign aid and foreign direct investment on three types of human rights: personal integrity, civil and political, and subsistence. I perform ordinary least squares regression analyses with panel-corrected standard errors on a pooled cross-sectional time series design incorporating 127 countries from 1976 to 1996. While my results are not significant, it is important to observe that there is a tendency toward negative relationships for the majority of the analyses.
Date: May 2007
Creator: Moses, Misty
System: The UNT Digital Library
Map-based cloning of the NIP gene in model legume Medicago truncatula. (open access)

Map-based cloning of the NIP gene in model legume Medicago truncatula.

Large amounts of industrial fertilizers are used to maximize crop yields. Unfortunately, they are not completely consumed by plants; consequently, this leads to soil pollution and negative effects on aquatic systems. An alternative to industrial fertilizers can be found in legume plants that provide a nitrogen source that is not harmful for the environment. Legume plants, through their symbiosis with soil bacteria called rhizobia, are able to reduce atmospheric nitrogen into ammonia, a biological nitrogen source. Establishment of the symbiosis requires communication on the molecular level between the two symbionts, which leads to changes on the cellular level and ultimately results in nitrogen-fixing nodule development. Inside the nodules hypoxic environment, the bacterial enzyme nitrogenase reduces atmospheric nitrogen to ammonia. Medicago truncatula is the model legume plant that is used to study symbiosis with mycorrhiza and with the bacteria Sinorhizobium meliloti. The focus of this work is the M. truncatula nodulation mutant nip (numerous infections and polyphenolics). The NIP gene plays a role in the formation and differentiation of nodules, and development of lateral roots. Studying this mutant will contribute knowledge to understanding the plant response to infection and how the invasion by rhizobia is regulated. Previous genetic mapping placed NIP …
Date: May 2007
Creator: Morris, Viktoriya
System: The UNT Digital Library
The Effects of Combining Positive and Negative Reinforcement During Training. (open access)

The Effects of Combining Positive and Negative Reinforcement During Training.

The purpose of this experiment was to compare the effects of combining negative reinforcement and positive reinforcement during teaching with the effects of using positive reinforcement alone. A behavior was trained under two stimulus conditions and procedures. One method involved presenting the cue ven and reinforcing successive approximations to the target behavior. The other method involved presenting the cue punir, physically prompting the target behavior by pulling the leash, and delivering a reinforcer. Three other behaviors were trained using the two cues contingent on their occurrence. The results suggest that stimuli associated with both a positive reinforcer and an aversive stimulus produce a different dynamic than a situation that uses positive reinforcement or punishment alone.
Date: May 2007
Creator: Murrey, Nicole A.
System: The UNT Digital Library
An Analysis of the Benefits of the Student Success Initiative in the 3rd and 5th Grades in a District in Texas. (open access)

An Analysis of the Benefits of the Student Success Initiative in the 3rd and 5th Grades in a District in Texas.

The state of Texas passed the Student Success Initiative (SSI) in 1999 which requires all 3rd graders to pass the reading portion of the Texas Assessment of Knowledge and Skills (TAKS) test to be promoted to the 4th grade, and for 5th graders to pass the reading and math portions of the TAKS test to be promoted to the 6th grade. Beginning in spring 2008, 8th graders will also need to pass the reading and math portions of the TAKS test to be promoted to the 9th grade. The purpose of this study was to examine the academic performance of 3rd and 5th grade students who did not meet the passing standard on the TAKS test and were retained during the 2005-2006 school year. The population of this study included 33 3rd graders and 49 5th graders who were retained during the 2005-2006 school year due to not meeting the promotion requirements of the SSI. There was also a second population of 49 5th graders who were retained in 3rd grade during the 2003-2004 school year due to not meeting the promotion requirements of the SSI. These students were enrolled in the 5th grade for the first time during the …
Date: May 2007
Creator: Neblett, Pamela S.
System: The UNT Digital Library
The Supply and Demand of Physician Assistants in the United States: A Trend Analysis (open access)

The Supply and Demand of Physician Assistants in the United States: A Trend Analysis

The supply of non-physician clinicians (NPCs), such as physician assistant (PAs), could significantly influence demand requirements in medical workforce projections. This study predicts supply of and demand for PAs from 2006 to 2020. The PA supply model utilized the number of certified PAs, the educational capacity (at 10% and 25% expansion) with assumed attrition rates, and retirement assumptions. Gross domestic product (GDP) chained in 2000 dollar and US population were utilized in a transfer function trend analyses with the number of PAs as the dependent variable for the PA demand model. Historical analyses revealed strong correlations between GDP and US population with the number of PAs. The number of currently certified PAs represents approximately 75% of the projected demand. At 10% growth, the supply and demand equilibrium for PAs will be reached in 2012. A 25% increase in new entrants causes equilibrium to be met one year earlier. Robust application trends in PA education enrollment (2.2 applicants per seat for PAs is the same as for allopathic medical school applicants) support predicted increases. However, other implications for the PA educational institutions include recruitment and retention of qualified faculty, clinical site maintenance and diversity of matriculates. Further research on factors affecting …
Date: May 2007
Creator: Orcutt, Venetia L.
System: The UNT Digital Library
One-to-one technology and mathematics achievement for eighth grade girls and boys in the state of Maine. (open access)

One-to-one technology and mathematics achievement for eighth grade girls and boys in the state of Maine.

This study analyzed the eighth grade mathematics portion of the spring 2004 Maine Educational Assessment (MEA) achievement test and the survey questions that were also administered. The analysis was on a school-wide level (n = 182). The two survey questions used were: “Which statement best describes the use of calculators in your mathematics classes?” and "Which statement best describes how you use your laptop in mathematics class: getting data from the Web, finding mathematics problems online, creating graphs?" Correlational analysis, partial correlation, and regression were used to determine if there was any association between calculator usage, laptop usage, and mathematics achievement for girls and for boys in the first state-wide group of students to have one-to-one laptops in Maine. Calculator usage was found to be positively associated with mathematics achievement for both girls (partial correlation coefficient of .189 (p = .011)) and for boys (partial correlation coefficient of .193 (p = .010)) even after controlling for school size and socio-economic status. Though no significant association between laptop usage and mathematics achievement for either girls or boys was found, this may be more a reflection on the survey question being a weak measure than the usage of laptops. In a post-hoc …
Date: May 2007
Creator: Overall, Theresa Lynne
System: The UNT Digital Library
Formation and Quantification of Corrosion Deposits in the Power Industry (open access)

Formation and Quantification of Corrosion Deposits in the Power Industry

The presence of deposits on the secondary side of pressurized water reactor (PWR) steam generator systems is one of the main contributors to the high maintenance costs of these generators. Formation and transport of corrosion products formed due to the presence of impurities, metals and metallic oxides in the secondary side of the steam generator units result in formation of deposits. This research deals with understanding the deposit formation and characterization of deposits by studying the samples collected from different units in secondary side system at Comanche Peak Steam Electric Station (CPSES). Fourier transform infrared spectrophotometry (FTIR), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) have been used for studying the phases, morphologies and compositions of the iron oxides formed at Unit 1 and Unit 2 of secondary side of steamgenerator systems. Hematite and magnetite were found to be the dominant phases of iron oxides present in the units. Fe, Cr, O, Ni, Si, Cl and Cu were found in samples collected from both the units. A qualitative method was developed to differentiate iron oxides using laser induced breakdown spectroscopy (LIBS) based on temporal response of iron oxides to a high power laser beam. A quantitative FTIR technique was …
Date: May 2007
Creator: Namduri, Haritha
System: The UNT Digital Library
CMOS Active Pixel Sensors for Digital Cameras: Current State-of-the-Art (open access)

CMOS Active Pixel Sensors for Digital Cameras: Current State-of-the-Art

Image sensors play a vital role in many image sensing and capture applications. Among the various types of image sensors, complementary metal oxide semiconductor (CMOS) based active pixel sensors (APS), which are characterized by reduced pixel size, give fast readouts and reduced noise. APS are used in many applications such as mobile cameras, digital cameras, Webcams, and many consumer, commercial and scientific applications. With these developments and applications, CMOS APS designs are challenging the old and mature technology of charged couple device (CCD) sensors. With the continuous improvements of APS architecture, pixel designs, along with the development of nanometer CMOS fabrications technologies, APS are optimized for optical sensing. In addition, APS offers very low-power and low-voltage operations and is suitable for monolithic integration, thus allowing manufacturers to integrate more functionality on the array and building low-cost camera-on-a-chip. In this thesis, I explore the current state-of-the-art of CMOS APS by examining various types of APS. I show design and simulation results of one of the most commonly used APS in consumer applications, i.e. photodiode based APS. We also present an approach for technology scaling of the devices in photodiode APS to present CMOS technologies. Finally, I present the most modern CMOS …
Date: May 2007
Creator: Palakodety, Atmaram
System: The UNT Digital Library
Resiliency and the successful first-generation community college student: Identifying effective student support services. (open access)

Resiliency and the successful first-generation community college student: Identifying effective student support services.

This study examined what differences in resiliency traits, if any, exist between successful and non-successful first and continuing-generation college students through the use of a survey. For the purposes of this study, first-generation students were those students whose parents have never attended college and continuing-generation college students were those students whose parents have attended some college. For the purposes of this study, the term successful was defined as those students who after being enrolled during fall 2005 re-enrolled for the spring 2006 semester and the term non-successful is defined as those students who after being enrolled fall 2005 semester failed to re-enrolled for the spring 2006 semester. A sample of 164 students was surveyed by collecting demographic data, resiliency traits, attitudinal characteristics, level of familial support, and reasons for dropping out of college. A sub-sample of 40 students participated in a face-to-face, in-depth interview. This study found that successful first-generation community college students possessed certain common qualities or resilient characteristics that include: 1) social competence, 2) problem-solving skills, 3) critical consciousness, 4) autonomy, and 5) sense of purpose. Through the face-to-face interviews common themes emerged. Many of the students used similar words to describe their feelings and experiences about beginning, …
Date: May 2007
Creator: Parrent, Condoa M.
System: The UNT Digital Library
Documentary Film: Accidental Shakespeare (open access)

Documentary Film: Accidental Shakespeare

According to the American Heritage College Dictionary, the word “community” derives from the Latin roots: communitas and communis meaning “fellowship” and “common,” respectively. The word “amateur” derives from the Latin roots: amator meaning “lover.” A community of amateurs, who love to put on plays, exists within the Denton Community Theatre. Their first attempt at classical theatre was the January 2006 production of Romeo and Juliet, directed by Brad Speck. The film follows two actors (through observational shooting) - Kevin Wickersham, a waiter who is trying theatre for the first time, and Jeffrey Johnson, a theatre college student trying Shakespeare for the first time - as they relate to a process and community that is new to them.
Date: May 2007
Creator: Petty, Laurel Ann
System: The UNT Digital Library
ADA Compliance and Accessibility of Aquatic Facilities in the North Texas Area (open access)

ADA Compliance and Accessibility of Aquatic Facilities in the North Texas Area

The purpose of this study was to determine the degree to which existing aquatic facilities in the North Texas metroplex complied with the 1991 Americans with Disabilities Act Accessibility Guidelines (ADAAG) and the proposed Americans with Disabilities Act Accessibility Guidelines: Recreation Facilities (ADAAG supplement). Fifty-two aquatic facilities were evaluated based on: parking lot, ticket counter, gate/entry, restroom, dressing area, drinking fountain, pathway, and pool entry method structural domains. Physical measurements and a few direct observations were recorded on the survey instrument. Surveys were then reviewed and facility scores were tabulated. No facility was found to be 100% compliant with ADAAG and the ADAAG supplement. Aquatic facilities are already struggling to catch up with the 1991 ADAAG, but when the United States Department of Justice approves the proposed ADAAG supplement, aquatic facilities will fall even further behind.
Date: May 2007
Creator: Pike, Hilary Eryn
System: The UNT Digital Library
Comparison of Evangelical Christian Children's God-Concepts and Logical Thinking Ability. (open access)

Comparison of Evangelical Christian Children's God-Concepts and Logical Thinking Ability.

God-concepts of 24 third to sixth grade evangelical Christian children were compared with the children‘s logical thinking abilities in a mixed-method study. Measurements included the Children‘s Interview and the Group Assessment of Logical Thinking (GALT). God-concepts among the children were Biblical, comforter, communicates, creator, empowering, protector, provider, purposeful, human characteristics, lives in heaven, male, counselor, God is Jesus, all-knowing, loving, perfect, powerful, real, and parental. The majority of concrete thinkers conceptualized God as a gracious guide. The majority of transitional thinkers viewed God also as a gracious guide as well as a distant divinity. Implications were given for religious educators to develop a model for age-appropriate instruction and curriculum and to equip parents to promote spiritual development with children at home.
Date: May 2007
Creator: Penick, Starrla
System: The UNT Digital Library
Amorphization and De-vitrification in Immiscible Copper-Niobium Alloy Thin Films (open access)

Amorphization and De-vitrification in Immiscible Copper-Niobium Alloy Thin Films

While amorphous phases have been reported in immiscible alloy systems, there is still some controversy regarding the reason for the stabilization of these unusual amorphous phases. Direct evidence of nanoscale phase separation within the amorphous phase forming in immiscible Cu-Nb alloy thin films using 3D atom probe tomography has been presented. This evidence clearly indicates that the nanoscale phase separation is responsible for the stabilization of the amorphous phase in such immiscible systems since it substantially reduces the free energy of the undercooled liquid (or amorphous) phase, below that of the competing supersaturated crystalline phases. The devitrification of the immiscible Cu-Nb thin film of composition Cu-45% Nb has been studied in detail with the discussion on the mechanism of phase transformation. The initial phase separation in the amorphous condition seems to play a vital role in the crystallization of the thin film. Detailed analysis has been done using X-ray diffraction, transmission electron microscopy and 3D atom probe tomography.
Date: May 2007
Creator: Puthucode Balakrishnan, Anantharamakrishnan
System: The UNT Digital Library
Males' Support Toward Females After Sexual Assault (open access)

Males' Support Toward Females After Sexual Assault

The current study explored the relations among rape myths, attitudes toward rape victims, perceived social support, sex role, and social reactions in a male undergraduate sample (N = 205). Males who have provided support to a sexual assault victim were compared to those who have not provided support to a sexual assault victim on several measures. Social reactions of those who have provided support to a sexual assault victim were compared to hypothetical reactions provided by individuals who have not previously provided support. Results indicated that rape related attitudes and beliefs did not differ between those who have and have not provided support to a sexual assault victim. In addition, individuals who were responding to a hypothetical situation reported that they would provide more positive social support than individuals who were responding to an actual situation. Implications for clinical work and future research in this area are discussed.
Date: May 2007
Creator: Reck, Jennifer K.
System: The UNT Digital Library
The Role of Social Capital in Organizations: The Precursors and Effects of Social Capital among Certified Nurse Aides in Nursing Homes (open access)

The Role of Social Capital in Organizations: The Precursors and Effects of Social Capital among Certified Nurse Aides in Nursing Homes

The role of social capital in forming organizational commitment is the focus of this research. Organizational social capital is the idea that social relationships have value in the organization. The theoretical framework is based on Kanter's (1993) structure of organizational commitment. This research views the structure within organizations based on global empowerment, job satisfaction, organizational commitment, and social capital. In addition, the role that race, income, and education affect the organizational structure is also taken into account. The organizational configuration was assembled using a structural equation model with latent variables employing a sample of 235 certified nurse aides. The sample was collected from 10 nursing homes in the Dallas-Ft.Worth metropolitan area. It was expected that Kanter's general format is reestablished within the sample. In fact, the study found that empowerment significantly influences job satisfaction. In turn, job satisfaction does foster organizational commitment. Although Kanter's original thesis was supported in this analysis, it was also determined that social capital plays a significant mediating role in creating organizational commitment. Furthermore, this research indicates that social capital alone can create organizational commitment. Thus, in conclusion, this research builds on Kanter's original idea and argues that organizational commitment is based on job satisfaction, global …
Date: May 2007
Creator: Potts, Helen
System: The UNT Digital Library
Determining the Relationship Between Motivation and Academic Outcomes Among Students in the Health Professions. (open access)

Determining the Relationship Between Motivation and Academic Outcomes Among Students in the Health Professions.

Admissions processes for health professions programs result in students entering these programs academically homogeneous. Yet some students have great difficulty with the programs. Research has shown a limited ability of traditional academic indicators to predict successful outcomes for health professions education. The purpose of this study was to examine the relationship between learning motivation and academic outcomes for students in health professions programs. The Modified Archer Health Professions Motivation Scale (MAHPMS) and a demographic survey were administered at orientation to 131 medical and 29 physician assistant students at the University of North Texas Health Science Center in the fall of 2005. At the end of the semester, the same version of the MAHPMS was administered, and final course grades and semester averages were collected. Descriptive statistics were analyzed for all the study variables. Analysis of variance was utilized to examine within subjects and between subjects differences for the learning motivation scores among programs and demographic categories. Linear regression analyses were used to determine the relationship between learning motivation scores and end-of-semester grades. And finally, logistic regression was performed to explore the ability of the motivation scores to predict academically high-risk students. Approximately three-fourths of the students indicated a preference for …
Date: May 2007
Creator: Reed, Linda E.
System: The UNT Digital Library
Beyond the "Year of Song": Text and Music in the Song Cycles of Robert Schumann after 1848 (open access)

Beyond the "Year of Song": Text and Music in the Song Cycles of Robert Schumann after 1848

In recent years scholars have begun to re-evaluate the works, writings, and life of Robert Schumann (1810-1856). One of the primary issues in this ongoing re-evaluation is a reassessment of the composer's late works (roughly defined as those written after 1845). Until recently, the last eight years of Schumann's creative life and the works he composed at that time either have been ignored or critiqued under an image of an illness that had caused periodic breakdowns. Schumann's late works show how his culture and the artists communicating within that culture were transformed from the beginning to the middle of the nineteenth century. These late works, therefore, should be viewed in the context of Schumann's output as a whole and in regard to their contributions to nineteenth-century society. Schumann's contributions, specifically to the genre of the song cycle from 1849 to 1852, are among his late compositional works that still await full reconsideration. A topical study, focusing on three themes of selections from his twenty-three late cycles, will provide a critical evaluation of Schumann's compositional output in the genre of the song cycle. First, Schumann's political voice will be examined. The political events that led to the mid-nineteenth-century revolutions inspired crucial …
Date: May 2007
Creator: Ringer, Rebecca Scharlene
System: The UNT Digital Library
Layered Double Hydroxides as Anion- and Cation-Exchanging Materials (open access)

Layered Double Hydroxides as Anion- and Cation-Exchanging Materials

Layered double hydroxides (LDH) have been principally known as anion-exchanging, clay-like materials for several decades, and continues to be the main driving force for current and future research. The chemical interactions of LDH, with transition metallocyanides, have been a popular topic of investigation for many years, partly due to the use of powder x-ray diffraction and infrared spectroscopy as the main characterization tools. Each transition metallocyanide has a characteristic infrared stretching frequency that can be easily observed, and their respective sizes can be observed while intercalated within the interlayer of the LDH. The ability of LDH to incorporate metal cations or any ions/molecules/complexes, that have a postive charge, have not been previously investigated, mainly due to the chemical and physical nature of LDH. The possibility of cationic incorporation with LDH would most likely occur by surface adsorption, lattice metal replacement, or by intercalation into the LDH interlayers. Although infrared spectroscopy finds it main use through the identification of the anions incorporated with LDH, it can also be used to study and identify the various active and inactive bending and stretching modes that the metal hydroxide layers have.
Date: May 2007
Creator: Richardson, Mickey Charles
System: The UNT Digital Library
An Examination of the Relationship Between Teacher Efficacy and Teachers' Perceptions of Their Principals' Leadership Behaviors (open access)

An Examination of the Relationship Between Teacher Efficacy and Teachers' Perceptions of Their Principals' Leadership Behaviors

Over the years there has been significant discussion of the connection between principal's leadership qualities and teacher efficacy. Students come to the classroom from stable, traditional, supportive home environments as well as from unstable, broken, and homeless situations. Teachers are asked to teach a classroom full of students with a wide range of learning abilities as well as a varied range of learning disabilities. The confidence to do this for the measure of a teacher's career takes a strong sense of efficacy. The purpose of this study was to examine the relationship between teachers' sense of efficacy and teachers' perceptions of their principals' leadership qualities that enhance and/or diminish the teachers' sense of efficacy. This study utilized both quantitative and qualitative research methods to study the effects of leadership qualities on teacher efficacy. Quantitative data was acquired utilizing the teacher sense of efficacy scale and the principal leadership questionnaire. Qualitative data was gathered through a focus group meeting of teachers with measurably strong efficacy to identify principal practices that affect teachers' efficacy. The study's outcomes reported that total respondent data indicates a generally positive relationship between these two variables. Subgroup analysis revealed varying results with diminishing relationships measured from elementary …
Date: May 2007
Creator: Ryan, Harry D.
System: The UNT Digital Library
Reflections on diversity: Graduate perceptions of campus climate at Dallas Theological Seminary, 1996-2005. (open access)

Reflections on diversity: Graduate perceptions of campus climate at Dallas Theological Seminary, 1996-2005.

The purpose of this study was to determine how graduates of master's degree programs perceived the ethnic and cultural climate at Dallas Theological Seminary (DTS) during their enrollment there. The population (N=2,223) consisted of graduates of master's degree programs who attended Dallas Seminary from 1996-2005. The study utilized a non-experimental design methodology using a mailed survey questionnaire. A 37.2 % response rate was achieved. Most results were statistically significant at the .05 alpha level utilizing chi-square goodness-of-fit tests.
Date: May 2007
Creator: Roy-Woods, Sabrina M.
System: The UNT Digital Library
Surface Engineering and Characterization of Laser Deposited Metallic Biomaterials (open access)

Surface Engineering and Characterization of Laser Deposited Metallic Biomaterials

Novel net shaping technique Laser Engineered Net shaping™ (LENS) laser based manufacturing solution (Sandia Corp., Albuquerque, NM); Laser can be used to deposit orthopedic implant alloys. Ti-35Nb-7Zr-5Ta (TNZT) alloy system was deposited using LENS. The corrosion resistance being an important prerequisite was tested electrochemically and was found that the LENS deposited TNZT was better than conventionally used Ti-6Al-4V in 0.1N HCl and a simulated body solution. A detailed analysis of the corrosion product exhibited the presence of complex oxides which are responsible for the excellent corrosion resistance. In addition, the in vitro tests done on LENS deposited TNZT showed that they have excellent biocompatibility. In order to improve the wear resistance of the TNZT system boride reinforcements were carried out in the matrix using LENS processing. The tribological response of the metal matrix composites was studied under different conditions and compared with Ti-6Al-4V. Usage of Si3N4 balls as a counterpart in the wear studies showed that there is boride pullout resulting in third body abrasive wear with higher coefficient of friction (COF). Using 440C stainless steel balls drastically improved the COF of as deposited TNZT+2B and seemed to eliminate the effect of “three body abrasive wear,” and also exhibited superior …
Date: May 2007
Creator: Samuel, Sonia
System: The UNT Digital Library
Bulk and Interfacial Effects on Density in Polymer Nanocomposites (open access)

Bulk and Interfacial Effects on Density in Polymer Nanocomposites

The barrier properties of polymers are a significant factor in determining the shelf or device lifetime in polymer packaging. Nanocomposites developed from the dispersion of nanometer thick platelets into a host polymer matrix have shown much promise. The magnitude of the benefit on permeability has been different depending on the polymer investigated or the degree of dispersion of the platelet in the polymer. In this dissertation, the effect of density changes in the bulk and at the polymer-platelet interface on permeability of polymer nanocomposites is investigated. Nanocomposites of nylon, PET, and PEN were processed by extrusion. Montmorillonite layered silicate (MLS) in a range of concentrations from 1 to 5% was blended with all three resins. Dispersion of the MLS in the matrix was investigated by using one or a combination of X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Variation in bulk density via crystallization was analyzed using differential scanning calorimetry (DSC) and polarized optical microscopy. Interfacial densification was investigated using force modulation atomic force microscopy (AFM) and ellipsometry. Mechanical properties are reported. Permeability of all films was measured in an in-house built permeability measurement system. The effect of polymer orientation and induced defects on permeability …
Date: May 2007
Creator: Sahu, Laxmi Kumari
System: The UNT Digital Library
State and local level implementation of schoolwide positive behavior support: An examination of the Texas Behavior Support Initiative (TBSI). (open access)

State and local level implementation of schoolwide positive behavior support: An examination of the Texas Behavior Support Initiative (TBSI).

This study examined the current status of schoolwide positive behavior support efforts in Texas. The study specifically (a) examined the impact of statewide positive behavior interventions and supports (PBIS) training on the rates of discipline records, in-school ¬suspensions, out-¬of¬-school suspensions, disciplinary alternative education placements, and expulsions of public schools in Texas; (b) investigated the overall effectiveness of schoolwide positive behavior support; and (c) determined the differences between rates of discipline records, in-school ¬suspensions, out-¬of¬-school suspensions, disciplinary alternative education placements, and expulsions in schools participating in the Texas Behavior Support Initiative (TBSI): Schoolwide PBS Project when compared with matching schools who did not participate in the project. This study demonstrated that schools can significantly reduce problem behavior in their schools when implementing PBIS with fidelity. Creating effective systems of PBIS required training, coaching, and on¬site technical assistance by trained and experienced PBIS facilitators.
Date: May 2007
Creator: Schultz, Edward K.
System: The UNT Digital Library