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 Collection: UNT Theses and Dissertations
The Law Concerning Trade Regulations Prio to the Twentieth Century

The Law Concerning Trade Regulations Prio to the Twentieth Century

Date: August 1963
Creator: Brabham, Billy J.
Description: This thesis discusses trade regulations throughout history.
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Lawrence Weiner's Concerto for Guitar and Orchestra: Analysis and Performance Considerations

Lawrence Weiner's Concerto for Guitar and Orchestra: Analysis and Performance Considerations

Date: August 2005
Creator: Tan, Wann-Dar
Description: The purpose of this dissertation is to provide an introduction to the composer, Lawrence Weiner, and to his Concerto for Guitar and Orchestra, one of the many neglected guitar concerti that merits closer study and more frequent performances. Weiner, a prolific and prominent composer in the South Texas region, composed the concerto in 1986. The concerto was never published. This dissertation is the first attempt to study Weiner's Concerto for Guitar and Orchestra to date. This study provides insight into the compositional style of Weiner, and the understanding and performing of this work. The compositional language of this concerto is examined through an analysis of the aspects of form, harmonic/tonal scheme and thematic development. A performance edition and suggestions that are approved by the composer are also presented.
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Layered Double Hydroxides and the Origins of Life on Earth

Layered Double Hydroxides and the Origins of Life on Earth

Access: Use of this item is restricted to the UNT Community.
Date: May 2001
Creator: Brister, Brian
Description: A brief introduction to the current state of research in the Origins of Life field is given in Part I of this work. Part II covers original research performed by the author and co-workers. Layered Double Hydroxide (LDH) systems are anion-exchanging clays that have the general formula M(II)xM(III)(OH)(2x+2)Y, where M(II) and M(III) are any divalent and trivalent metals, respectively. Y can be nearly any anion, although modern naturally occuring LDH systems incorporate carbonate (CO32-), chloride (Cl-), or sulfate (SO42-) anions. Intercalated cobalticyanide anion shows a small yet observable deviation from local Oh symmetry causing small differences between its oriented and non-oriented infrared spectra. Nitroprusside is shown to intercalate into 2:1 Mg:Al LDH with decomposition to form intercalated ferrocyanide and nitrosyl groups of an unidentified nature. The [Ru(CN)6]4- anion is shown to intercalate into layered double hydroxides in the same manner as other hexacyano anions, such as ferrocyanide and cobalticyanide, with its three-fold rotational axis perpendicular to the hydroxide sheets. The square-planar tetracyano-nickelate(II), -palladate(II), and platinate(II) anions were intercalated into both 2:1 and 3:1 Mg:Al layered double hydroxides (LDH). The basal spacings in the 2:1 hosts are approximately 11 Å, indicating that the anions are inclined approximately 75 degrees relative to ...
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Layered Double Hydroxides as Anion- and Cation-Exchanging Materials

Layered Double Hydroxides as Anion- and Cation-Exchanging Materials

Date: May 2007
Creator: Richardson, Mickey Charles
Description: 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.
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Layered Double Hydroxides: Morphology, Interlayer Anion, and the Origins of Life

Layered Double Hydroxides: Morphology, Interlayer Anion, and the Origins of Life

Access: Use of this item is restricted to the UNT Community.
Date: December 2002
Creator: Halcom-Yarberry, Faith Marie
Description: The preparation of layered double hydroxides via co-precipitation of a divalent/trivalent metal solution against a base results in 1 mm LDH particles with a disorganized metal lattice. Research was performed to address these morphological issues using techniques such as Ostwald ripening and precipitation via aluminate. Another interesting issue in layered double hydroxide materials is the uptake and orientation of anions into the interlayer. Questions about iron cyanide interlayer anions have been posed. Fourier transform infared spectroscopy and powder x-ray diffraction have been used to investigate these topics. It was found that factors such as orientation, anion charge, and anion structure depended on the divalent/trivalent metal ratio of the hydroxide layer and reactivity time. The cyanide self-addition reaction is an important reaction of classical prebiotic chemistry. This reaction has been shown to give rise to amino acids, purines and pyrimidines. At cyanide concentrations similar to that expected on the early earth, hydrolysis to formamide rather than self-addition occurs. One theory to alleviate this side reaction is the use of minerals or clays that are thought to concentrate and catalyze prebiotics of interest. Layered double hydroxides have been studied as a catalyst for this reaction.
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Layered Double Hydroxides: Synthesis, Characterization, and Interaction of Mg-Al Systems with Intercalated Tetracyanonickelate(II)

Layered Double Hydroxides: Synthesis, Characterization, and Interaction of Mg-Al Systems with Intercalated Tetracyanonickelate(II)

Date: August 2004
Creator: Brister, Fang Wei
Description: The square-planar tetracyanonickelate(II) anion was intercalated into 2:1 and 3:1 Mg-Al layered double hydroxide systems (LDHs). In the 2:1 material, the anion holds itself at an angle of about 30° to the layers, whereas in the 3:1 material it lies more or less parallel to the layers. This is confirmed by orientation effects in the infrared spectra of the intercalated materials and by X-ray diffraction (XRD) data. The measured basal spacings for the intercalated LDH hosts are approximately 11 Å for the 2:1 and approximately 8 Å for the 3:1. The IR of the 2:1 material shows a slight splitting in the ν(CN) peak, which is suppressed in that compound's oriented IR spectrum, indicating that at least some of the intercalated anion's polarization is along the z-axis. This effect is not seen in the 3:1 material. A comparison between chloride LDHs and nitrate LDHs was made with respect to intercalation of tetracyanonickelate(II) anions. Both XRD data and atomic absorption spectroscopy (AAS) data of the LDH tetracyanonickelates confirms that there are no significant differences between the products from the two types of starting materials. The presence of a weak ν(NO) peak in the IR spectra of those samples made from nitrate ...
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Laying the foundation for successful non-academic writing: Professional communication principles in the K-5 curricula of the McKinney Independent School District.

Laying the foundation for successful non-academic writing: Professional communication principles in the K-5 curricula of the McKinney Independent School District.

Date: December 2009
Creator: Treviño, Marlea
Description: Traditionally, K-5 students' writing has had a primarily academic aim-to help students master concepts and express themselves. Even if students take a professional writing course later, they typically do not have the opportunity to practice-over the long period of time mastery requires-the non-academic writing skills they will be required to use as part of their jobs and in their civic life. Based on a limited K-5 study, Texas' McKinney Independent School District is doing a good job of preparing students at the elementary-school level in the areas of collaboration and presentation. A fair job of helping elementary-school students understand the communication situation, define audience, clarify purpose, gather and evaluate resources, and test usability. [And] a poor job of helping elementary-school students with analysis and organization. With their teachers' help, K-5 students eventually grasp the communication situation and can broadly identify their audience and purpose, but they do not appear to select words, format, communication style, or design based on that audience and purpose. Their writer-based focus affects their presentations as well, although they do present frequently. If teachers routinely incorporated audience and purpose considerations into every aspect of communication assignments (format, communication style, design), students would be better prepared for ...
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A Layman's Interpretation of the Provisions of a 20-Year Pay Life Insurance Policy

A Layman's Interpretation of the Provisions of a 20-Year Pay Life Insurance Policy

Date: August 1940
Creator: James, Albert W., Jr.
Description: This thesis presents an attempt to simplify the language used in life insurance provisions.
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Layout-accurate Ultra-fast System-level Design Exploration Through Verilog-ams

Layout-accurate Ultra-fast System-level Design Exploration Through Verilog-ams

Date: May 2013
Creator: Zheng, Geng
Description: This research addresses problems in designing analog and mixed-signal (AMS) systems by bridging the gap between system-level and circuit-level simulation by making simulations fast like system-level and accurate like circuit-level. The tools proposed include metamodel integrated Verilog-AMS based design exploration flows. The research involves design centering, metamodel generation flows for creating efficient behavioral models, and Verilog-AMS integration techniques for model realization. The core of the proposed solution is transistor-level and layout-level metamodeling and their incorporation in Verilog-AMS. Metamodeling is used to construct efficient and layout-accurate surrogate models for AMS system building blocks. Verilog-AMS, an AMS hardware description language, is employed to build surrogate model implementations that can be simulated with industrial standard simulators. The case-study circuits and systems include an operational amplifier (OP-AMP), a voltage-controlled oscillator (VCO), a charge-pump phase-locked loop (PLL), and a continuous-time delta-sigma modulator (DSM). The minimum and maximum error rates of the proposed OP-AMP model are 0.11 % and 2.86 %, respectively. The error rates for the PLL lock time and power estimation are 0.7 % and 3.0 %, respectively. The OP-AMP optimization using the proposed approach is ~17000× faster than the transistor-level model based approach. The optimization achieves a ~4× power reduction for the OP-AMP ...
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Leader Developmental Readiness of Generation Y in the Training Industry

Leader Developmental Readiness of Generation Y in the Training Industry

Date: December 2012
Creator: Garrigue, Marie
Description: Members of Generation Y in the training and development industry will be required to assume leadership roles as Baby Boomers retire, yet little empirical research exists regarding how best to prepare them for leadership. The purpose of this study was to examine differences in leader developmental readiness between generational cohorts in the training industry, specifically Baby Boomers, Generation X, and Generation Y. Leader developmental readiness provided a definition of developmental readiness for leaders using the five constructs (learning goal orientation, developmental efficacy, self-awareness, leader complexity, and metacognitive ability). A volunteer sample was compiled from members of the ASTD National LinkedIN group (n = 636). Results were analyzed using structured means analysis with maximum likelihood (ML) estimation. Generational cohorts demonstrated differences in leader developmental readiness. Baby Boomers indicated statistically and practically higher metacognitive ability and developmental efficacy than Generation Y. Results demonstrated statistically and practically higher leader complexity in Generation Y and both Generation X and Baby Boomers. These results should inform leader development practitioners as they continue to use existing methods in preparing the different generations for leader development interventions while pointing to possible needs to increase the metacognitive ability and developmental efficacy in Generation Y and ensure accurate perception ...
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