You limited your search to:

  Access Rights: Public
  Partner: UNT Libraries
 Decade: 2000-2009
 Collection: UNT Theses and Dissertations
Latent Transition Analysis of Pre-service Teachers' Efficacy in Mathematics and Science

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

Date: December 2009
Creator: Ward, Elizabeth Kennedy
Description: 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.
Contributing Partner: UNT Libraries
Learner-to-Learner: Refocusing the Lens of Educational Immediacy

Learner-to-Learner: Refocusing the Lens of Educational Immediacy

Date: May 2009
Creator: Keller, Christine Ida
Description: As the current body of instructional communication research focuses primarily on the relationship between teacher and learner, three studies investigating the relationship between learners were completed in order to better understand how student motivation and learning are influenced by learner-to-learner immediacy behaviors within the college classroom environment. Study I resulted in an extensive list of both positive and negative verbal and nonverbal immediacy behaviors commonly used by learners. Study II required the comparison of the behaviors identified in study one to existing measures of teacher to learner immediacy behaviors, producing a new measure focusing on learner-to-learner immediacy. Following a pilot survey, the reliability of this new measure was determined through face validity and factor analysis, producing the Learner-to-Learner Immediacy Behavior Scale. In Study III, the Learner-to-Learner Immediacy Behavior Scale was combined with Christophel's 1990 Immediacy Behavior Scale, Cognitive Learning Scale, Affective Learning Scale, and Trait and State Motivation Scales and administered to 273 undergraduate students to test the affects of common learner-to-learner immediacy behaviors on student state motivation, affective learning, and perceptions of cognitive learning loss. Multiple regression analyses indicated learner-to-learner immediacy as functioning similarly to teacher-to-student immediacy when mediated through state motivation in its influence on student affective learning ...
Contributing Partner: UNT Libraries
Racial Stereotypes and Racial Assimilation in a Multiracial Society

Racial Stereotypes and Racial Assimilation in a Multiracial Society

Date: December 2009
Creator: Youngblood, Thomas
Description: 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.
Contributing Partner: UNT Libraries
Predicting Chemical and Biochemical Properties Using the Abraham General Solvation Model

Predicting Chemical and Biochemical Properties Using the Abraham General Solvation Model

Date: May 2009
Creator: Mintz, Christina
Description: Several studies were done to illustrate the versatillity of the Abraham model in mathematically describing the various solute-solvent interactions found in a wide range of different chemical and biological systems. The first study focused on using the solvation model to construct mathematical correlations describing the minimum inhibitory concentration of organic compounds for growth inhibition towards the three bacterial strains Porphyromonas gingivalis, Selenomonas artemidis, and Streptococcus sobrinus. The next several studies expand the practicallity of the Abraham model by predicting free energies of partition in chemical systems. The free energy studies expand the use of the Abraham model to other temperatures and properties by developing correlations for the enthalpies of solvation of gaseous solutes of various compounds dissolved in water, 1-octanol, hexane, heptane, hexadecane, cyclohexane, benzene, toluene, carbon tetrachloride, chloroform, methanol, ethanol, 1-butanol, propylene carbonate, dimethyl sulfoxide, 1,2-dichloroethane, N,N-dimethylformamide, tert-butanol, dibutyl ether, ethyl acetate, acetonitrile, and acetone. Also, a generic equation for linear alkanes is created for use when individual datasets are small. The prediction of enthalpies of solvation is furthered by modifying the Abraham model so that experimental data measured at different temperatures can be included into a single correlation expression. The temperature dependence is directly included in the model ...
Contributing Partner: UNT Libraries
Investigating the effects on parallel play between siblings: Teaching children with autism to emit social phrases to their typically developing sibling.

Investigating the effects on parallel play between siblings: Teaching children with autism to emit social phrases to their typically developing sibling.

Date: December 2008
Creator: Hille, Katrina J.
Description: The focus of this study was three fold. First, modeling and feedback were investigated as a training package for social interactions between siblings. Second, the effects of social phrases taught to the sibling with autism were investigated. Third, the magnitude of these social phrases was measured by timing duration of parallel play. The experimental design is an A-B-A1-A2 design conducted in a clinic, with a probe for generalization in the home environment. This intervention was replicated across an additional sibling dyad to indicate its effectiveness. This study ascertained that the sibling with autism was a viable participant in learning new social skills that could function as a behavioral cusp and increase sibling interactions.
Contributing Partner: UNT Libraries
A New Wireless Sensor Node Design for Program Isolation and Power Flexibility

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

Date: December 2009
Creator: Skelton, Adam W.
Description: 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.
Contributing Partner: UNT Libraries
Grounds-Based and Grounds-Free Voluntarily Child Free Couples: Privacy Management and Reactions of Social Network Members

Grounds-Based and Grounds-Free Voluntarily Child Free Couples: Privacy Management and Reactions of Social Network Members

Date: May 2009
Creator: Regehr, Kelly A.
Description: Voluntarily child free (VCF) individuals face stigmatization in a pronatalist society that labels those who do not want children as deviant. Because of this stigmatization, VCF couples face privacy issues as they choose to reveal or conceal their family planning decision and face a variety of reactions from social network members. Therefore, communication privacy management and communication accommodation theory was use to examine this phenomenon. Prior research found two different types of VCF couples: grounds-based and grounds-free. Grounds-based individuals cite medical or biological reasons for not having children, while grounds-free individuals cite social reasons for not having children. The purpose of this study is to examine how grounds-based and grounds-free VCF couples manage their disclosure of private information and how social network members react to their family planning decision. Findings revealed that grounds-free individuals are more likely to engage in the self-defense hypothesis and grounds-based individuals are more likely to engage in the expressive need hypothesis. Grounds-based individuals were asked about their decision in dyadic situations, whereas grounds-free individuals were asked at group gatherings. Additionally, social network members used under-accommodation strategies the most frequently and grounds-free individuals experienced more name calling than grounds-based. Finally, while grounds-free individuals experienced non-accommodation and ...
Contributing Partner: UNT Libraries
Slaves and Slaveholders in the Choctaw Nation: 1830-1866

Slaves and Slaveholders in the Choctaw Nation: 1830-1866

Date: May 2009
Creator: Fortney, Jeffrey L., Jr.
Description: Racial slavery was a critical element in the cultural development of the Choctaws and was a derivative of the peculiar institution in southern states. The idea of genial and hospitable slave owners can no more be conclusively demonstrated for the Choctaws than for the antebellum South. The participation of Choctaws in the Civil War and formal alliance with the Confederacy was dominantly influenced by the slaveholding and a connection with southern identity, but was also influenced by financial concerns and an inability to remain neutral than a protection of the peculiar institution. Had the Civil War not taken place, the rate of Choctaw slave ownership possibly would have reached the level of southern states and the Choctaws would be considered part of the South.
Contributing Partner: UNT Libraries
An Evaluation of the Effects of Two Different Role Play Formats on the Outcomes of a Parent Training Curriculum

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

Date: December 2009
Creator: Carlson Litscher, Barbara J.
Description: 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.
Contributing Partner: UNT Libraries
Primary Stylistic Characteristics of Cindy McTee's Music as found in Timepiece, Ballet for Band and Finish Line

Primary Stylistic Characteristics of Cindy McTee's Music as found in Timepiece, Ballet for Band and Finish Line

Date: May 2009
Creator: Williams, Nicholas E.
Description: Cindy McTee, Regents Professor of Composition in the College of Music at the University of North Texas, is one of America's leading composers. Her music is an eclectic blend of the "American" sound that is created by the use of a multiplicity of techniques. This document uses three of McTee's most recent (to date) works for wind band: Timepiece, Ballet for Band and Finish Line, to identify the primary stylistic characteristic's of the composer's music, which include: jazz influence; use of ostinati, pseudo-ostinati and machine-like rhythmic patterns and figures; creation of extended and angular melodic lines; progressive "walking" bass lines; and the use of octatonic and chromatic collections. Through the identification of stylistic characteristics, concise stylistic analysis of the works, interview transcript, list of composer's works to date, and selected discography, this document will add to the limited body of scholarly writing on the composer.
Contributing Partner: UNT Libraries
Thermochemical investigations of crystalline solutes in non-electrolyte solutions: Mathematical representation of solubility data and the development of predictive solubility equations in systems with specific and non-specific interactions.

Thermochemical investigations of crystalline solutes in non-electrolyte solutions: Mathematical representation of solubility data and the development of predictive solubility equations in systems with specific and non-specific interactions.

Date: May 2008
Creator: Zvaigzne, Anita Ilze
Description: Understanding the thermodynamic properties of multicomponent mixtures is of critical importance in many chemical and industrial applications. Experimental measurements become progressively difficult as the number of solution components increases -- producing the need for predictive models. Problems in development of predictive models arise if the mixture has one or more components that interact through molecular complexation or association. Experimental solubilities of anthracene and pyrene dissolved in binary systems containing one or more alcohols were measured in order to address this problem. Alcohols examined in this study were: 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, and 1-octanol. In binary solvent mixtures containing only a single self-associating alcoholic solvent, the alkane cosolvents studied were: n-hexane, n-heptane, n-octane, 2,2,4-trimethylpentane, cyclohexane, methylcyclohexane, tert-butylcyclohexane. Predictive solubility equations were developed using mobile order theory. This approach differs from classical solution models by representing hydrogen bonding with a probability term rather than with expressions derived from stepwise equilibria or expressions to represent hypothetical solution aggregates. Results were compared with the predicted solubilities found from using expressions developed using the Kretschmer-Wiebe and Mecke-Kempter approaches for modeling associated solutions. It was found that the mobile order approach provided reasonably accurate predictions for the solute solubilities in the systems studied. The ...
Contributing Partner: UNT Libraries
Survey of Approximation Algorithms for Set Cover Problem

Survey of Approximation Algorithms for Set Cover Problem

Date: December 2009
Creator: Dutta, Himanshu Shekhar
Description: In this thesis, I survey 11 approximation algorithms for unweighted set cover problem. I have also implemented the three algorithms and created a software library that stores the code I have written. The algorithms I survey are: 1. Johnson's standard greedy; 2. f-frequency greedy; 3. Goldsmidt, Hochbaum and Yu's modified greedy; 4. Halldorsson's local optimization; 5. Dur and Furer semi local optimization; 6. Asaf Levin's improvement to Dur and Furer; 7. Simple rounding; 8. Randomized rounding; 9. LP duality; 10. Primal-dual schema; and 11. Network flow technique. Most of the algorithms surveyed are refinements of standard greedy algorithm.
Contributing Partner: UNT Libraries
Processing, Structure, and Tribological Property Interrelationships in Sputtered Nanocrystalline ZnO Coatings

Processing, Structure, and Tribological Property Interrelationships in Sputtered Nanocrystalline ZnO Coatings

Date: August 2009
Creator: Tu, Wei-Lun
Description: Solid lubricant coatings with controlled microstructures are good candidates in providing lubricity in moving mechanical assembly applications, such as orthopedics and bearing steels. Nanocrystalline ZnO coatings with a layered wurtzite crystal structure have the potential to function as a lubricious material by its defective structure which is controlled by sputter deposition. The interrelationships between sputtered ZnO, its nanocrystalline structure and its lubricity will be discussed in this thesis. The nanocrystalline ZnO coatings were deposited on silicon substrates and Ti alloys by RF magnetron sputtering with different substrate adhesion layers, direct current biases, and temperatures. X-ray diffraction identified that the ZnO (0002) preferred orientation was necessary to achieve low sliding friction and wear along with substrate biasing. In addition, other analyses such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) were utilized to study the solid lubrication mechanisms responsible for low friction and wear.
Contributing Partner: UNT Libraries
Tsunami disaster response: A case analysis of the information society in Thailand.

Tsunami disaster response: A case analysis of the information society in Thailand.

Date: December 2009
Creator: Aswalap, Supaluk Joy
Description: The December 2004 Indian Ocean Tsunami wrecked thousands of lives, homes, and livelihoods - losses that could have been avoided with timely and better information. A resource such as information is needed at a fundamental level much like water, food, medicine, or shelter. This dissertation examines the development of the Thai information society, in terms of the share of information workforce and the level of diffusion of information and communication technologies (ICT), as well as, the role of the Thai information society in response to the tsunami disaster. The study combined the historical and political economy analyses in explaining factors influencing the growth of information workforce and the development of ICT in Thailand. Interviews conducted in 2007-08 revealed the Thai information society responded to the 2004 Tsunami - the first global internet-mediated natural disaster - in two areas: on-site assistance in collecting and recording identification information of tsunami disaster victims and on-line dissemination of disaster relief information. The effectiveness of ICT institutions in providing the tsunami disaster relief efforts and increasing the development of the information society were assessed using statistical procedures analyzing the perceptions of the Internet-based survey respondents. The disaster effects on survey respondents were also assessed. The ...
Contributing Partner: UNT Libraries
The Influence of Giovanni Bottesini (1821-1889) on Pedro Valls (1869-1935): An Analysis of Homenaje à Bottesini (1906) by Pedro Valls

The Influence of Giovanni Bottesini (1821-1889) on Pedro Valls (1869-1935): An Analysis of Homenaje à Bottesini (1906) by Pedro Valls

Date: December 2009
Creator: Amorim, George
Description: This document traces a link between Pedro Valls and Giovanni Bottesini by identifying traits of Homenaje à Bottesini that resemble techniques and musical characteristics of Bottesini's music, through the comparison of Valls' Homenaje à Bottesini to Bottesini's Fantasia sur La Sonnambula, focusing on the works formal, musical and idiomatic characteristics. This is supported by documented evidence of Bottesini's presence in Spain during Valls's lifetime and Pedro Valls contact with the Italian master of the double bass school of playing and teaching method. This study also proposes adjustments in the notation of Homenaje à Bottesini to more modern and player-friendly score indications, which will help its inclusion into the active double bass repertoire. This document examines performance practice(s) of the work and what advantages or disadvantages these practices have in playing the work, and to ultimately offer a clear pathway, a road map, to performers interested in delving into Pedro Valls's work, with a better idea of what Valls's style consists of and what approach to take when performing his works.
Contributing Partner: UNT Libraries
State Level Causes of Terrorism: Limits on Political Expression

State Level Causes of Terrorism: Limits on Political Expression

Date: December 2009
Creator: Case, Erik S.
Description: Expanding on prior research into the state level causes of terrorism, I argue that state repression and limited state capacity reduces opportunities for non-violent political expression and increases the utility of terrorism. I also argue that economic freedom can is a form of political expression that can dissipate political grievances. While previous authors analyzed some of these variables separately using data on transnational attacks, I created a complete model incorporating the three categories of variables and tested my hypotheses using data that includes both domestic and transnational attacks. I use regression analysis for hypothesis testing and find support for the three primary contentions of this thesis and conclude that limits on political expression increase the likelihood nations will experienced increased levels of terrorism.
Contributing Partner: UNT Libraries
What has Damascus to do with Paris? A Comparative Analysis of Ibn Taymiyya and Gregory of Rimini: A Fourteenth Century and Late Medieval Rejection of the Use of Aristotelian Logic in the Legitimization of Divine Revelation in the Christian and Islamic Traditions

What has Damascus to do with Paris? A Comparative Analysis of Ibn Taymiyya and Gregory of Rimini: A Fourteenth Century and Late Medieval Rejection of the Use of Aristotelian Logic in the Legitimization of Divine Revelation in the Christian and Islamic Traditions

Date: December 2009
Creator: Chelvan, Richard D.
Description: This thesis is a comparative analysis of Ibn Taymiyya of Damascus and Gregory of Rimini within their respective religious and philosophical traditions. Ibn Taymiyya and Gregory of Rimini rejected the use of Aristotelian logic in the valorization of divine revelation in Islam and Christianity respectively. The translation movements, in Baghdad and then in Toledo, ensured the transmission of Greek scientific and philosophical works to both the Islamic world during the 'Abbasid Caliphate and the Catholic Christian European milieu beginning in the eleventh century. By the fourteenth century both the Islamic and the Catholic European religious traditions had a long history of assimilating Aristotle's Organon. Ibn Taymiyya and Gregory of Rimini rejected the notion, adopted by the kalam and scholastic traditions respectively, that logical demonstration could be used to validate religious doctrine as taught in the Qur'an and the Bible. Ibn Taymiyya rejected demonstration completely but Gregory accepted its qualified use.
Contributing Partner: UNT Libraries
Process of identifying a guiding theory: An exploratory study.

Process of identifying a guiding theory: An exploratory study.

Date: August 2009
Creator: Burwell-Pender, Lezlie
Description: At the University of North Texas, and as per the Council for Accreditation of Counseling and Related Educational Programs (CACREP) standards, masters students in counselor training are required to choose a personal theoretical approach to the counseling process. The purpose of this study was to investigate an experimental counseling theory identification procedure compared to the traditional procedure of helping students identify a personal theory of counseling. The investigation assessed the effect on 1) counselor self-report of confidence in theoretical orientation selection/identification, and 2) the degree to which a student consistently identifies, conceptualizes and utilizes a particular counseling theoretical approach. Volunteer participants (n=35) were recruited from three sections of COUN 5660 and were randomly drawn to group assignment within each class. The experimental condition focused on exploration of personal beliefs related to human nature, maladjustment and the nature of change as a basis for theory selection. The comparison group received the standard theory selection activities. The TCQ and TOPS-R were used to examine the effect of treatment and were administered at three points of time. Data was analyzed using a split plot ANOVA to examine group differences, changes across time, and the possible interaction of change with group membership. Statistical and ...
Contributing Partner: UNT Libraries
The Parent Participation Discourse of a Community School: Diverse Ideas and Perceptions about Educational Partnership at an Inner City Community School

The Parent Participation Discourse of a Community School: Diverse Ideas and Perceptions about Educational Partnership at an Inner City Community School

Date: August 2009
Creator: Coe, Alice Elizabeth
Description: Despite the widespread recommendation that schools "collaborate" with parents, little is found in the literature to elaborate on what this term or the common synonym "partnership" means, and further, how schools can invite diverse parental contributions to the table of educational discourse. The current study looks to contribute to the literature by analyzing the parent participation discourse in one community elementary school, utilizing critical discourse analysis and ethnographic observations. The findings reveal both school and parents' conceptions of the parents' partnership role as ancillary to that of the school's and the subsequent lack of true collaboration so advocated by the literature. Implications arise from this analysis which calls into question the examples of "collaboration" found in the literature, given the lack of theorizing regarding what collaboration inside of parent participation means. Contributions may shed light on the unintentional inequality of diverse parents in an effort toward true collaboration utilizing both the European American, middle class contributions of the educational institution alongside those of non-mainstream parents in creating an authentic educational atmosphere for diverse students.
Contributing Partner: UNT Libraries
The Impact of IT Capability on Employee Capability, Customer Value, Customer Satisfaction, and Business Performance

The Impact of IT Capability on Employee Capability, Customer Value, Customer Satisfaction, and Business Performance

Date: August 2009
Creator: Chae, Ho-Chang
Description: This study empirically examines the impact of IT capability on firms' performance and evaluates whether firms' IT capabilities play a role in improving employee capability, customer value, customer satisfaction, and ultimately business performance. The results were based on comparing the business performance of the IT leader companies with that of control companies of similar size and industry. The IT leader companies were selected from the Information Week 500 list published annually from 2001 to 2004. For a company to be selected as IT leaders, it needed to be listed at least twice during the period. Furthermore, it had to be listed in the American Customer Satisfaction Index (ACSI) so that its customer satisfaction level could be assessed. Standard & Poor's Compustat and the ACSI scores were used to test for changes in business performance. The study found that the IT leaders had a raw material cost measured by cost-of-goods-sold to sales ratio (COGS/S) than the control companies. However, it found no evidence that firms' IT capability affects employee capability, customer value, customer satisfaction, and profit. An important implication from this study is that IT becomes a commodity and an attempt to gain a competitive advantage by overinvesting in IT may ...
Contributing Partner: UNT Libraries
The Turn from Reactive to Responsive Environmentalism: The Wilderness Debate, Relational Metaphors, and the Eco-Phenomenology of Response

The Turn from Reactive to Responsive Environmentalism: The Wilderness Debate, Relational Metaphors, and the Eco-Phenomenology of Response

Date: December 2009
Creator: Christion, Timothy C.
Description: A shift is occurring in environmentalism to a post-metaphysical understanding of the human relationship to nature. Stemming from developments within the wilderness debate, ecofeminism, and eco-phenomenology, the old dichotomy between John Muir's tradition of privileging nature and Gifford Pinchot's tradition of privileging society is giving way to a relational paradigm that privileges neither. The starting point for this involves articulating the ontology of relationship anew. Insofar as the dominant metaphors of nature and their complimentary narratives present a choice between the agency of the human or the natural worlds, they encourage one-sided or "reactive" relationships to the world. By contrast, developments sensitive to the mutual agency between them encourage "responsive" relationships. The relational metaphors of "partnership" (Merchant) and "dialogue" (Plumwood) are prominent examples. The idea of "nonhuman agency," however, is counter-intuitive and problematic. The works of Buber, Heidegger, and Merleau-Ponty suggest a model of "mutual response" rather than "mutual agency."
Contributing Partner: UNT Libraries
Growth and Characterization of β-Iron Disilicide, β-Iron Silicon Germanide, and Osmium Silicides

Growth and Characterization of β-Iron Disilicide, β-Iron Silicon Germanide, and Osmium Silicides

Date: August 2009
Creator: Cottier, Ryan James
Description: The semiconducting silicides offer significant potential for use in optoelectronic devices. Full implementation of the materials, however, requires the ability to tailor the energy gap and band structure to permit the synthesis of heterojunctions. One promising approach is to alloy the silicides with Ge. As part of an investigation into the synthesis of semiconducting silicide heterostructures, a series of β-Fe(Si1−xGex)2 epilayer samples, with nominal alloy content in the range 0 < x < 0.15, have been prepared by molecular beam epitaxy on Si(100). I present results of the epitaxial and crystalline quality of the films, as determined by reflection high-energy electron diffraction, Rutherford backscattering spectroscopy, and double crystal x-ray diffraction, and of the band gap dependence on the alloy composition, as determined by Fourier transform infrared spectroscopy. A reduction in band gap was observed with increasing Ge content, in agreement with previous theoretical predictions. However Ge segregation was also observed in β-Fe(Si1−xGex)2 epilayers when x > 0.04. Osmium silicide films have been grown by molecular beam epitaxy on Si(100). The silicides have been grown using e-beam evaporation sources for both Os and Si onto Si(100) substrates at varying growth rates and temperatures ranging from 600-700ºC. The resulting films have been ...
Contributing Partner: UNT Libraries
Negative affect and positive symptoms of psychosis.

Negative affect and positive symptoms of psychosis.

Date: December 2009
Creator: Crutchfield, Audra
Description: The current study utilized structural equation modeling (SEM) to examine the factor-to-factor relations and temporal associations between disturbances in negative affect (NA) and positive symptoms of psychosis (PP). Data were drawn from a large, public-domain data set (MacArthur Violence Risk Assessment Study). A dimensional approach was used to conceptualize and identify latent variables of NA (depression, anxiety, and guilt) and PP (hallucinations, delusions, and thought disorder) among individuals with a diagnosis of primary psychotic disorder. Results showed that anxiety, guilt, and depressed mood modeled an NA latent variable, and that hallucinations and unusual thought content modeled a PP latent variable. As predicted, results revealed strong, significant cross-sectional (synchronous) associations between NA and PP at each measured time-frame, suggesting that NA and PP occurred concurrently within the sample. Contrary to predictions, no significant cross-lagged effect between NA and PP was identified (10 weeks and 20 weeks respectively).
Contributing Partner: UNT Libraries
The Impact of Legal Sanctions on Recidivism Rates among Male Perpetrators of Domestic Violence

The Impact of Legal Sanctions on Recidivism Rates among Male Perpetrators of Domestic Violence

Date: December 2009
Creator: Cosimo, S. Deborah
Description: Using a Cox proportional hazards regression model, this dissertation explores three factors currently not addressed in the literature on men who batter women and who are court ordered to participate in a battering intervention program. These factors are the cumulative effects of civil and criminal legal sanctions (dose-response of sanctions) for domestic violence related offenses on recidivism, reduced opportunities to recidivate, and whether the number of legal sanctions imposed has an effect on how long a man maintains his non-recidivism status. Because one domestic violence case may involve multiple sanctions, this study uses the Legal Sanction Dose-Response Index to gauge the cumulative impact of civil and criminal sanctions upon recidivism of domestic violence. The Cox proportional hazards model indicates that the risk of recidivism is 45% lower for men who experienced two legal sanctions (typically arrest and probation) in response to the index case, relative to men who experienced one legal sanction (typically civil protective order). In other words, those with two legal sanctions are able to maintain their non-recidivism status longer relative to those with one sanction. Men with prior criminal court involvement for domestic violence related offenses are more likely to recidivate. Additionally, rather than incarceration reducing opportunities ...
Contributing Partner: UNT Libraries
FIRST PREV 1 2 3 4 5 NEXT LAST