115 Matching Results

Results open in a new window/tab.

Biomolecular Assembly of Gold Nanocrystals (open access)

Biomolecular Assembly of Gold Nanocrystals

Over the past ten years, methods have been developed to construct discrete nanostructures using nanocrystals and biomolecules. While these frequently consist of gold nanocrystals and DNA, semiconductor nanocrystals as well as antibodies and enzymes have also been used. One example of discrete nanostructures is dimers of gold nanocrystals linked together with complementary DNA. This type of nanostructure is also known as a nanocrystal molecule. Discrete nanostructures of this kind have a number of potential applications, from highly parallel self-assembly of electronics components and rapid read-out of DNA computations to biological imaging and a variety of bioassays. My research focused in three main areas. The first area, the refinement of electrophoresis as a purification and characterization method, included application of agarose gel electrophoresis to the purification of discrete gold nanocrystal/DNA conjugates and nanocrystal molecules, as well as development of a more detailed understanding of the hydrodynamic behavior of these materials in gels. The second area, the development of methods for quantitative analysis of transmission electron microscope data, used computer programs written to find pair correlations as well as higher order correlations. With these programs, it is possible to reliably locate and measure nanocrystal molecules in TEM images. The final area of …
Date: May 20, 2005
Creator: Micheel, Christine Marya
System: The UNT Digital Library
Synthesis, Structure, and Reactivity ofbis(1,2,4-tri-t-butylcyclopentadienyl) Complexes of Cerium (open access)

Synthesis, Structure, and Reactivity ofbis(1,2,4-tri-t-butylcyclopentadienyl) Complexes of Cerium

The sterically demanding 1,2,4-tri-t-butylcyclopentadienylligand (1,2,4-(Me3C)3C5H2, hereafter Cp') has been used to preparemonomeric cerium metallocenes, Cp 2CeX (X = Cl, I, OSO2CF3), which areused to synthesize the benzyl, Cp'2CeCH2C6H5. The benzyl is a usefulstarting material for preparing other complexes in the Cp'2CeZ system (Z= BF4, F, NH2, C6H5, H). X-ray crystal structures of Cp'2CeOSO2CF3,Cp'2CeF, Cp'2CeCH2C6H5, and Cp'2CeH are presented. The benzyl slowlydecomposes in solution to toluene and a metallacycle,[Cp'][(Me3C)2C5H2(CMe2CH2)]Ce. The ring CMe3 groups of both themetallacycle and the hydride, Cp'2CeH, can be fully deuterated byprolonged exposure to C6D6, providing a useful labeling tool inmechanistic studies.The hydride activates C-F and/or C-H bonds influorobenzenes, C6HxF6-x , x = 0-5. The reactions are selective, with theselectivity depending on the presence of two fluorines ortho to thereaction site more than on the type of bond activated. Complexes of thetype Cp'2CeC6HxF5-x , x = 0-4, are formed as intermediates, which slowlydecompose in solution to Cp'2CeF and fluorobenzynes, C6HxF4-x, x = 0-4,which are trapped. The rate at which Cp'2CeC6HxF5-x complexes decomposeincreases as the number of fluorines decreases. Complexes with oneortho-fluorine decompose much faster than those with two ortho-fluorines.The metallacycle activates only C-H bonds in fluorobenzenes, permittingthe synthesis of specific Cp'2CeC6HxF5-x complexes. The crystal structureof Cp'2CeC6F5 is presented. …
Date: May 19, 2005
Creator: Werkema, Evan L.
System: The UNT Digital Library
Length-Limited Data Transformation and Compression (open access)

Length-Limited Data Transformation and Compression

Scientific computation is used for the simulation of increasingly complex phenomena, and generates data sets of ever increasing size, often on the order of terabytes. All of this data creates difficulties. Several problems that have been identified are (1) the inability to effectively handle the massive amounts of data created, (2) the inability to get the data off the computer and into storage fast enough, and (3) the inability of a remote user to easily obtain a rendered image of the data resulting from a simulation run. This dissertation presents several techniques that were developed to address these issues. The first is a prototype bin coder based on variable-to-variable length codes. The codes utilized are created through a process of parse tree leaf merging, rather than the common practice of leaf extension. This coder is very fast and its compression efficiency is comparable to other state-of-the-art coders. The second contribution is the Piecewise-Linear Haar (PLHaar) transform, a reversible n-bit to n-bit wavelet-like transform. PLHaar is simple to implement, ideal for environments where transform coefficients must be kept the same size as the original data, and is the only n-bit to n-bit transform suitable for both lossy and lossless coding.
Date: May 17, 2005
Creator: Senecal, J G
System: The UNT Digital Library
I. Excluded Volume Effects in Ising Cluster Distributions and Nuclear Multifragmentation II. Multiple-Chance Effects in Alpha-Particle Evaporation (open access)

I. Excluded Volume Effects in Ising Cluster Distributions and Nuclear Multifragmentation II. Multiple-Chance Effects in Alpha-Particle Evaporation

In Part 1, geometric clusters of the Ising model are studied as possible model clusters for nuclear multifragmentation. These clusters may not be considered as non-interacting (ideal gas) due to excluded volume effect which predominantly is the artifact of the cluster's finite size. Interaction significantly complicates the use of clusters in the analysis of thermodynamic systems. Stillinger's theory is used as a basis for the analysis, which within the RFL (Reiss, Frisch, Lebowitz) fluid-of-spheres approximation produces a prediction for cluster concentrations well obeyed by geometric clusters of the Ising model. If thermodynamic condition of phase coexistence is met, these concentrations can be incorporated into a differential equation procedure of moderate complexity to elucidate the liquid-vapor phase diagram of the system with cluster interaction included. The drawback of increased complexity is outweighted by the reward of greater accuracy of the phase diagram, as it is demonstrated by the Ising model. A novel nuclear-cluster analysis procedure is developed by modifying Fisher's model to contain cluster interaction and employing the differential equation procedure to obtain thermodynamic variables. With this procedure applied to geometric clusters, the guidelines are developed to look for excluded volume effect in nuclear multifragmentation. In part 2, an explanation is …
Date: May 16, 2005
Creator: Breus, Dimitry E.
System: The UNT Digital Library
Measurement of differential cross sections and Cx and Cz for gamma photon-proton going to kaon-lambda baryon and gamma photon-proton going to kaon-sigma baryon using CLAS at Jefferson Lab (open access)

Measurement of differential cross sections and Cx and Cz for gamma photon-proton going to kaon-lambda baryon and gamma photon-proton going to kaon-sigma baryon using CLAS at Jefferson Lab

This work presents several observables for the reactions γ<italic> p</italic> → <italic>K</italic><super>+</super>Λ and γ<italic> p</italic> → <italic>K</italic><super>+</super>Σ°. In addition to measuring differential cross sections, we have made first measurements of the double polarization observables <italic>C<sub>x</sub></italic> and <italic> C<sub>z</sub></italic>. <italic>C<sub>x</sub></italic> and <italic>C<sub> z</sub></italic> characterize the transfer of polarization from the incident photon to the produced hyperons. Data were obtained at Jefferson Lab using a circularly polarized photon beam at endpoint energies of 2.4, 2.9, and 3.1 GeV. Events were detected with the CLAS spectrometer. In the Λ channel, the cross sections support the recent observation of new resonant structure at <italic>W</italic> = 1900 MeV. Studies of the invariant cross section, <math> <f> <fr><nu>d<g>s</g></nu><de>dd</de></fr></f> </math> show scaling behavior suggesting that the production mechanism becomes <italic> t</italic>-channel dominated near threshold at forward kaon angles. The double polarization observables show that the recoiling Λ is almost maximally polarized along the direction of the incident photon from mid to forward kaon angles. While Σ<super>o</super> differential cross sections are of the same magnitude as the Λ differential cross sections, there is evidence of different physics dominating the production mechanism. The Σ° invariant cross sections do not show the same <italic>t</italic>-scaling behavior present in the Λ results. …
Date: May 11, 2005
Creator: Bradford, Robert
System: The UNT Digital Library
A texture-based framework for improving CFD data visualization in a virtual environment (open access)

A texture-based framework for improving CFD data visualization in a virtual environment

In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated hut require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx}10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as density, temperature, pressure, and velocity magnitude are properties that are typically calculated and stored in a dataset solution. Solutions are not limited to just scalar properties. Vector quantities, such as velocity, are also often calculated and stored for a CFD simulation. Accessing all of this data efficiently during runtime is a key problem for visualization in an interactive application. Understanding simulation solutions requires a post-processing tool to convert the data into something more meaningful. Ideally, the application would present an interactive visual representation of the numerical data for any dataset that was simulated while maintaining the accuracy of the calculated solution. Most CFD applications currently sacrifice interactivity for accuracy, yielding highly detailed flow descriptions hut limiting interaction for investigating the field.
Date: May 5, 2005
Creator: Bivins, Gerrick O'Ron
System: The UNT Digital Library
The Administration of Spain Under Charles V, Spain's New Charlemagne (open access)

The Administration of Spain Under Charles V, Spain's New Charlemagne

Charles I, King of Spain, or Charles V, Holy Roman Emperor, was the most powerful ruler in Europe since Charlemagne. With a Germanic background, and speaking French, Charles became King of Spain in 1516. Yet secondary sources and available sixteenth century Spanish sources such as Spanish Royal Council records, local records of Castro Urdiales in Castile, and Charles's correspondence show that he continued the policies of his predecessors in Spain, Ferdinand of Aragon and Isabella of Castile. He strove to strengthen his power and unify Spain and his empire using Castilian strength, a Castilian model of government, Roman law, religion, his strong personality, and a loyal and talented bureaucracy. Charles desired to be another Charlemagne, but with his base of power in Spain.
Date: May 2005
Creator: Beard, Joseph
System: The UNT Digital Library
Amon Carter: The Founder of Modern Fort Worth, 1930-1955 (open access)

Amon Carter: The Founder of Modern Fort Worth, 1930-1955

From 1930 to 1955, Amon Carter, publisher of the Fort Worth Star-Telegram, exerted his power to create modern Fort Worth. Carter used his stature as the publisher of the city's major newspaper to build a modern city out of this livestock center. Between 1930 and 1955, Carter lobbied successfully for New Deal funds for Fort Worth, persuaded Consolidated Aircraft to build an airplane plant in the city, and convinced Burlington Railways to stay in the city. He also labored unsuccessfully to have the Trinity River Canal built and to secure a General Motors plant for Fort Worth. These efforts demonstrate that Carter was indeed the founder of modern Fort Worth.
Date: May 2005
Creator: Cervantez, Brian
System: The UNT Digital Library
An Analysis of On-Campus Housing at Public Rural Community Colleges in the United States (open access)

An Analysis of On-Campus Housing at Public Rural Community Colleges in the United States

This study has two purposes. First is to dispel myths that there are no residence halls at community colleges. Second is to discuss the ways in which these residence halls are administered, the amenities offered to students, the benefits of residence halls, and their future in community colleges. The study is based upon the Katsinas, Lacey and Hardy 2004 classifications and divides community colleges into 7 categories: Urban multi campus, Urban single campus, Suburban multi campus, Suburban single campus, and Rural small, medium and large. Included in the study are tables of data received from an original survey sent to 232 community college CEOs who reported to the US Department of Education that they had residence halls at their campus. The results indicate that a significant number of community colleges with residence halls exist, particularly at rural community colleges, that they bring significant financial gain to the colleges, and they append numerous benefits to students and to student life at these colleges. Residence halls are housed in divisions of student services and directed by experienced student affairs professionals. The study concludes with recommendations for policy as well as practice, the most important of which calls for more accurate data collection …
Date: May 2005
Creator: Moeck, Pat Gallagher
System: The UNT Digital Library
Assessing Allied Health and Nursing Post-Secondary Career and Technical Education Teacher Attitudes and Beliefs About Reading (open access)

Assessing Allied Health and Nursing Post-Secondary Career and Technical Education Teacher Attitudes and Beliefs About Reading

This study examined allied health and nursing career and technical education (CTE) teacher beliefs and attitudes about reading. Since beliefs and attitudes influence the way teachers teach, it is important to understand what those beliefs and attitudes are, especially in relationship to reading in subject matter classrooms. One hundred twelve individuals responded to a written survey concerning their attitudes and beliefs about reading. A four-factor solution was achieved with a principal components factor analysis. A significant number of variables were associated with the factor labeled Reading Apathy, which appears to be indicative of the condition known as aliteracy among faculty who participated in the study. Professional development activities grounded in novice-to-expert theory are suggested as a way of overcoming the phenomenon. Recommendations for future research involve a more detailed study to further characterize the condition of aliteracy and its impact on student learning.
Date: May 2005
Creator: Moore, Bridgit R.
System: The UNT Digital Library
Assessing the Adlerian Personality Priorities: A Formal Instrument for Therapeutic Practice (open access)

Assessing the Adlerian Personality Priorities: A Formal Instrument for Therapeutic Practice

The purpose of this study was to develop an effective formal instrument to assess the Adlerian personality priorities. The development of the Allen Assessment for Adlerian Personality Priorities, AAAPP, seeks to provide a strong comparability to assessing the Adlerian construct of personality priorities as the counselor interview. One hundred and seven participants were given the 1st administration of the AAAPP, Social Interest Scale and a demographic survey. Sixty-four participants completed a 2nd administration of the AAAPP two weeks later. Twenty participants experienced a counseling interview following the 2nd administration. The methods used to evaluate the validity and effectiveness of the AAAPP included: face validity, predictive validity, construct validity, test-retest reliability, multiple regression, Guttman split-half reliability and the Spearman Brown reliability.
Date: May 2005
Creator: Allen, Elizabeth Gayle Soules
System: The UNT Digital Library
The breakdown of de Gennes Scaling in TbxEr1-xNi2B2C and its mean field theory explanation (open access)

The breakdown of de Gennes Scaling in TbxEr1-xNi2B2C and its mean field theory explanation

The Neel temperatures, T{sub N}, of Tb{sub x}Er{sub 1-x}Ni{sub 2}B{sub 2}C samples have been determined from the temperature dependence of magnetization measurements. A breakdown of the de Gennes scaling of T{sub N} with a clear turning point around x = 0.45 has been observed. The T{sub N} values of Tb{sub x}Er{sub 1-x}Ni{sub 2}B{sub 2}C do not change much within the range of O &lt; x &lt; 0.45 and then, for larger x they increase almost linearly with concentration until T{sub N} = 14.9K is reached for x = 1, TbNi{sub 2}B{sub 2}C. The clear change in the x-dependence of T{sub N} around x = 0.45 can be linked to a change in the local moment ordering direction from transverse to longitudinal, a change which is consistent with recent resonant X-ray scattering data. These features in T{sub N}(x) can be explained using a mean field model.
Date: May 1, 2005
Creator: Gao, Chunwang
System: The UNT Digital Library

Challenges Encountered During Law Enforcement Investigations of Terrorist Use of Information Technology.

Access: Use of this item is restricted to the UNT Community
The late 20th and early 21st centuries have seen a phenomenal growth in society's use of information technology. Criminals, including terrorists and terrorist organizations, have also adopted information technologies. Information technologies are used to enhance the efficiency, productivity, and effectiveness of terrorist activities and offenses. Investigating terrorist use of information technologies creates a number of challenges for law enforcement officials. While some of the challenges are encountered during conventional criminal investigations, terrorist investigations also present unique challenges. Through content and typological analysis, this study examined open source information to identify, categorize and propose a model of these challenges. Four primary categories were identified: technology, methodology, legal, and administration and human resources challenges.
Date: May 2005
Creator: Morgan, Deanne
System: The UNT Digital Library
Character Education Programs and Student Suspension Rates from School: Do Character Education Programs Decrease Student Suspensions from Regular Instructional Public Elementary Schools in Texas? (open access)

Character Education Programs and Student Suspension Rates from School: Do Character Education Programs Decrease Student Suspensions from Regular Instructional Public Elementary Schools in Texas?

The purpose of this study was to determine if character education programs impact the suspension rates of students from regular instructional public elementary schools in Texas. The data was also examined to determine if the number of years since a school's implementation of a character education program has an impact on the effectiveness of the programs as measured by the suspension rates of students from school. Finally, the study sought to determine if the socio-economic status of the schools has an impact on the effectiveness of character education programs as measured by the student suspension rates. A random sample of 135 regular instructional public elementary schools in Texas was collected. The principal of each school completed a questionnaire that was used to sort schools into three groups: schools with "direct" character education programs, schools with "indirect" character education programs, and schools that have implemented no type of character education program. A two-year history of suspensions was obtained for each school. The data was analyzed using one-way and two-way ANOVAs. The results of the analyses indicated that the implementation of character education programs, no matter what type, did not produce statistically significant differences in student suspension rates from school. Furthermore, the …
Date: May 2005
Creator: Grinage, Adam L.
System: The UNT Digital Library

Characterization of Infection Arrest Mutants of Medicago Truncatula and Genetic Mapping of Their Respective Genes.

Access: Use of this item is restricted to the UNT Community
In response to compatible rhizobia, leguminous plants develop unique plant organs, root nodules, in which rhizobia fix nitrogen into ammonia. During nodule invasion, the rhizobia gain access to newly divided cells, the nodule primordia, in the root inner cortex through plant-derived cellulose tubes called infection threads. Infection threads begin in curled root hairs and bring rhizobia into the root crossing several cell layers in the process. Ultimately the rhizobia are deposited within nodule primordium cells through a process resembling endocytosis. Plant host mechanisms underlying the formation and regulation of the invasion process are not understood. To identify and clone plant genes required for nodule invasion, recent efforts have focused on Medicago truncatula. In a collaborative effort the nodulation defect in the lin (lumpy infections) mutant was characterized. From an EMS-mutagenized population of M. truncatula, two non-allelic mutants nip (numerous infections with polyphenolics) and sli (sluggish infections) were identified with defects in nodule invasion. Infection threads were found to proliferate abnormally in the nip mutant nodules with only very rare deposition of rhizobia within plant host cells. nip nodules were found to accumulate polyphenolic compounds, indicative of a host defense response. Interestingly, nip was also found to have defective lateral root …
Date: May 2005
Creator: Veereshlingam, Harita
System: The UNT Digital Library
Charge Interaction Effects in Epoxy with Cation Exchanged Montmorillonite Clay and Carbon Nanotubes. (open access)

Charge Interaction Effects in Epoxy with Cation Exchanged Montmorillonite Clay and Carbon Nanotubes.

The influence of charge heterogeneity in nanoparticles such as montmorillonite layered silicates (MLS) and hybrid systems of MLS + carbon nanotubes was investigated in cured and uncured epoxy. Epoxy nanocomposites made with cation-exchanged montmorillonite clay were found to form agglomerates near a critical concentration. Using differential scanning calorimetry it was determined that the mixing temperature of the epoxy + MLS mixture prior to the addition of the curing agent critically influenced the formation of the agglomerate. Cured epoxy samples showed evidence of the agglomerate being residual charge driven by maxima and minima in the concentration profiles of thermal conductivity and dielectric permittivity respectively. A hybrid nanocomposite of MLS and aniline functionalized multi walled nanotubes indicated no agglomerates. The influence of environmentally and process driven properties on the nanocomposites was investigated by examination of moisture, ultrasound, microwaves and mechanical fatigue on the properties of the hybrid systems. The results point to the importance of charge screening by adsorbed or reacted water and on nanoparticulates.
Date: May 2005
Creator: Butzloff, Peter Robert
System: The UNT Digital Library
Chemistry, Detection, and Control of Metals during Silicon Processing (open access)

Chemistry, Detection, and Control of Metals during Silicon Processing

This dissertation focuses on the chemistry, detection, and control of metals and metal contaminants during manufacturing of integrated circuits (ICs) on silicon wafers. Chapter 1 begins with an overview of IC manufacturing, including discussion of the common aqueous cleaning solutions, metallization processes, and analytical techniques that will be investigated in subsequent chapters. Chapter 2 covers initial investigations into the chemistry of the SC2 clean - a mixture of HCl, H2O2, and DI water - especially on the behavior of H2O2 in this solution and the impact of HCl concentration on metal removal from particle addition to silicon oxide surfaces. Chapter 3 includes a more generalized investigation of the chemistry of metal ions in solution and how they react with the silicon oxide surfaces they are brought into contact with, concluding with illumination of the fundamental chemical principles that govern their behavior. Chapter 4 shows how metal contaminants behave on silicon wafers when subjected to the high temperature (≥ 800 °C) thermal cycles that are encountered in IC manufacturing. It demonstrates that knowledge of some fundamental thermodynamic properties of the metals allow accurate prediction of what will happen to a metal during these processes. Chapter 5 covers a very different but …
Date: May 2005
Creator: Hurd, Trace Q.
System: The UNT Digital Library
A Comparative Analysis of Style of User Interface Look and Feel in a Synchronous Computer Supported Cooperative Work Environment (open access)

A Comparative Analysis of Style of User Interface Look and Feel in a Synchronous Computer Supported Cooperative Work Environment

The purpose of this study is to determine whether the style of a user interface (i.e., its look and feel) has an effect on the usability of a synchronous computer supported cooperative work (CSCW) environment for delivering Internet-based collaborative content. The problem motivating this study is that people who are located in different places need to be able to communicate with one another. One way to do this is by using complex computer tools that allow users to share information, documents, programs, etc. As an increasing number of business organizations require workers to use these types of complex communication tools, it is important to determine how users regard these types of tools and whether they are perceived to be useful. If a tool, or interface, is not perceived to be useful then it is often not used, or used ineffectively. As organizations strive to improve communication with and among users by providing more Internet-based collaborative environments, the users' experience in this form of delivery may be tied to a style of user interface look and feel that could negatively affect their overall acceptance and satisfaction of the collaborative environment. The significance of this study is that it applies the technology …
Date: May 2005
Creator: Livingston, Alan
System: The UNT Digital Library
A Comparison of Academic Achievement of Economically Disadvantaged Elementary Students Served in Title I Part A Programs: Targeted Assistance Versus Schoolwide Models (open access)

A Comparison of Academic Achievement of Economically Disadvantaged Elementary Students Served in Title I Part A Programs: Targeted Assistance Versus Schoolwide Models

This study analyzed test scores of economically disadvantaged students who attended two elementary schools implementing different types of Title I models from 1999-2001. Test scores from the Texas Assessment of Academic Skills (TAAS), the Iowa Test of Basic Skills (ITBS) and the Stanford Achievement Test (SAT-9) were analyzed. One school implemented the targeted assistance model (less than 50% poverty), which focused resources on students were identified as failing or at risk of failing. The other a schoolwide model (95% poverty), which used resources to help all students in a school regardless of whether they ware failing, at risk of failing, or economically disadvantaged. The quantitative approach was used with a causal comparative design. A cohort of continuously enrolled students was identified for the TAAS (n=169 and 189) and the ITBS/SAT-9 (n=49 and 87). Descriptive statistics such as the frequency, mean, and standard deviation, were used to measure differences on the Texas Learning Index (TLI) for the TAAS, and Normal Curve Equivalent (NCE) on the ITBS/SAT-9. Analysis of covariance (ANCOVA) was used to partially adjust for preexisting differences among the groups and because randomization was not possible. The independent variable was type of Title I model, targeted assistance or schoolwide. The …
Date: May 2005
Creator: Hinojosa, Marco A.
System: The UNT Digital Library
Connecting Ireland and America: Early English Colonial Theory 1560-1620 (open access)

Connecting Ireland and America: Early English Colonial Theory 1560-1620

This work demonstrates the connections that exist in rhetoric and planning between the Irish plantation projects in the Ards, Munster , Ulster and the Jamestown colony in Virginia . The planners of these projects focused on the creation of internal stability rather than the mission to 'civilize' the natives. The continuity between these projects is examined on several points: the rhetoric the English used to describe the native peoples and the lands to be colonized, who initiated each project, funding and financial terms, the manner of establishing title, the manner of granting the lands to settlers, and the status the natives were expected to hold in the plantation. Comparison of these points highlights the early English colonial idea and the variance between rhetoric and planning.
Date: May 2005
Creator: Nelson, Robert Nicholas
System: The UNT Digital Library

The Constitutionality of Dress Code and Uniform Policies

Access: Use of this item is restricted to the UNT Community
This dissertation proposes to delineate the criteria for determining the constitutionality of public school dress codes based on an examination of relevant case law. The study addresses the following underlying questions: (1) Do students have a constitutional right to freedom of choice regarding their personal dress and grooming in public schools? (2) If so, what is the origin of the right? (3) What justification does a school district need in order to intrude upon the right? (4) Does the extent to which there is a right, and that it is accorded support by the judiciary, depend on the student's age and grade level? (5) What do state statutes say about dress codes and uniforms? (6) Do state statutes comport with the circuit courts' rulings in the various jurisdictions? The first part of Chapter I examines the purpose of school uniforms as set forth in relevant educational literature and commentary. The second part of the chapter examines empirical evidence on the effects of dress codes and uniforms. Chapter II addresses the first three questions listed above concerning students' right to choice in personal dress, the origins of such a right, and the justification required for a school to intrude upon this …
Date: May 2005
Creator: Stromberger, Joanne
System: The UNT Digital Library
Coordination of dibensothiophenes and corannulenes to organometallic ruthenium (II) fragments (open access)

Coordination of dibensothiophenes and corannulenes to organometallic ruthenium (II) fragments

This dissertation contains five papers in the format required for journal publication which describe (in part) my research accomplishments as a graduate student at Iowa State University. This work can be broadly categorized as the binding of weakly-coordinating ligands to cationic organometallic ruthenium fragments, and consists of two main areas of study. Chapters 2-4 are investigations into factors that influence the binding of dibenzothiophenes to {l_brace}Cp'Ru(CO){sub 2}{r_brace}{sup +} fragments, where Cp' = {eta}{sup 5}-C{sub 5}H{sub 5} (Cp) and {eta}{sup 5}-C{sub 5}Me{sub 5} (Cp*). Chapters 5 and 6 present the synthesis and structural characterization of complexes containing corannulene buckybowls that are {eta}{sup 6}-coordinated to {l_brace}Cp*Ru{r_brace}{sup +} fragments. The first chapter contains a brief description of the difficulty in lowering sulfur levels in diesel fuel along with a review of corannulene derivatives and their metal complexes. After the final paper is a short summary of the work herein (Chapter 7). Each chapter is independent, and all equations, schemes, figures, tables, references, and appendices in this dissertation pertain only to the chapter in which they appear.
Date: May 1, 2005
Creator: Vecchi, Paul Anthony
System: The UNT Digital Library
Design and Empirical Analysis of a Model of Empowering Leadership. (open access)

Design and Empirical Analysis of a Model of Empowering Leadership.

Mid-level leaders are often expected to implement employee empowerment initiatives, yet many do not have a clear understanding of how to empower employees. To address this issue, a model of empowering leadership was developed. The model presents specific, actionable behaviors that a leader should perform in order to empower employees. The model comprises 13 factors built around the areas of ability, accountability, and authority. First, leaders must ensure employees have the ability to be empowered. To do so, they must (a) build employee organizational knowledge, (b) provide access to pertinent information, (c) assure employees have the necessary skill set, and (d) identify and provide needed resources. Second, leaders must create systems of accountability for employee outcomes by (e) setting a standard of continuous improvement, (f) recognizing and rewarding good work, (g) regularly evaluating employee efforts, and (h) providing continuous feedback on employee efforts. Third, leaders should provide employees with the authority to be empowered by (i) serving as advocates of employee efforts, (j) providing an environment that is conducive to empowerment, (k) setting a clear and consistent direction to guide employee efforts, and (l) building systems and structures to support employee empowerment. The thirteenth factor of the model is a …
Date: May 2005
Creator: Bodner, Sarah L.
System: The UNT Digital Library