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Study and Sample Implementation of the Secure Shell Protocol (SSH)

Description: Security is one of the main concerns of users who need to connect to a remote computer for various purposes, such as checking e-mails or viewing files. However in today's computer networks, privacy, transmission to intended client is not guaranteed. If data is transmitted over the Internet or a local network as plain text it may be captured and viewed by anyone with little technical knowledge. This may include sensitive data such as passwords. Big businesses use firewalls, virtual private networks and encrypt their transmissions to counter this at high costs. Secure shell protocol (SSH) provides an answer to this. SSH is a software protocol for secure communication over an insecure network. SSH not only offers authentication of hosts but also encrypts the sessions between the client and the server and is transparent to the end user. This Problem in Lieu of Thesis makes a study of SSH and creates a sample secure client and server which follows SSH and examines its performance.
Date: May 2003
Creator: Subramanyam, Udayakiran

A Study of Breath Management as Treated by Four Major American Vocal Pedagogues: Appelman, Reid, Vennard, and Miller

Description: Trained musicians cannot use the same breath process in daily living as for singing. Also, the normal breath cycle applied to speech is not efficient. Therefore, students who are learning to sing need to know proper breathing techniques. In this thesis, I will describe the breathing process and the correct way to breathe while singing, based on studies of four American pedagogues; Appleman, Reid, Vennard and Miller. To understand the breathing process for singing, it is necessary to study and understand the anatomical system and the mechanics of the respiratory system. Therefore, the first chapter contains anatomical system of breath management. Then, in the second chapter, the specific breath management techniques of four American pedagogues will be examined and compared. Three of them, Appelman, Vennard, and Miller, suggested some exercises in order to develop correct and efficient breathing habits.
Date: August 2005
Creator: Kim, Jisuk

A study of computer technology use and technology leadership of Texas elementary public school principals.

Description: The purpose of this study was to determine Texas elementary principals' level of computer technology use and their leadership in technology integration activities as defined by the National Educational Technology Standards for Administrators (NETS*A). Additionally the study addressed technology implementation as an innovation and used the literature concerning change and innovation models to identify organizational and personal factors that might affect the level of technology use and the leadership behaviors. Survey data retrieved from 216 Texas elementary public school principals led to the formation of the following conclusions. The elementary principals involved this study reported high level computer technology use, especially with the computer tools involving communication. Principals also reported high level leadership performance to the NETS*A standards. Multiple analyses of variance (MANOVA) revealed no significant difference in mean scores between the dependent variables of computer use or leadership performance to the NETS*A standards and the independent variables including the organizational factors of school location, district spending per student, campus minority status, and campus Title I status. A regression analysis revealed a statistically significant positive relationship between principals' computer technology use and personal variables of training and perceived risk-benefit. Another regression analysis revealed a statistically significant relationship between principals' technology leadership performance to the NETS*A standards and personal variables of training, perceived risk-benefit and perceived pressure to implement technology. Multiple regression analyses revealed no correlation between the dependent variables of technology use and technology leadership. A correlation analysis revealed a weak correlation between the two dependent variables with less than 4% of the variance explained by that relationship. There is a need for continuing research examining possible relationships between principals' technology use, their technology leadership behaviors, and the degree of technology integration in their schools. The findings from this study could be used by principal preparation programs to focus on ...
Date: May 2006
Creator: Weber, Mark J.

Study of Conductance Quantization by Cross-Wire Junction

Description: The thesis studied quantized conductance in nanocontacts formed between two thin gold wires with one of the wires coated by alkainthiol self assembly monolayers (SAM), by using the cross-wire junction. Using the Lorenz force as the driving force, we can bring the two wires in contact in a controlled manner. We observed conductance with steps of 2e2 / h. The conductance plateaus last several seconds. The stability of the junction is attributed to the fact that the coating of SAM improves the stability and capability of the formed contact.
Date: May 2004
Creator: Zheng, Tao

A study of continuing bonds and their impact on life attitudes in parents of murdered children.

Description: For most of the past century, the positive outcome of grief in the West was characterized as the relinquishment of the bond to the deceased. Phrases such as "let go", "move on", and "get over it" were, and continue to be, common to the language of this pursuit. This 'breaking bonds' perspective does not take into account other means of grief resolution, nor does it consider historical or cultural findings. Consequently, reports of bereaved parents who indicate resolution of grief yet maintain a continued relationship with their deceased child were not given much attention until the 1990s. This research employed a Durkheimian approach, taking the social bond as the starting point of inquiry and examined continuing bonds of parents to their murdered children. How these bonds were related to the parents' attitudes of re-investing in life and their level of grief was measured. The relationship between the parents' level of grief and their life attitudes was also assessed. The sample consisted of 46 parents living in North Texas whose child had been murdered three or more years ago. A triangulated methodology was utilized and the data were collected by means of participant observation, unstructured interviews, and a mailed questionnaire which obtained information on continuing bonds, level of grief, life attitudes and demographic variables. Multiple regression techniques were utilized to analyze the quantitative data. Parents on the Continuing Bonds Scale reported high levels of bonds with their deceased child. Contrary to expectation, the level of continuing bonds parents maintained with their children was found to be independent of other variables in the study. The relationship between parents' level of grief and their life attitudes was inverse in that higher levels of grief were associated with lower levels of re-investing in life. The finding of the independence of the Continuing Bonds Scale ...
Date: May 2006
Creator: Haag, Marcy J.

A study of Franz Liszt's Totentanz: Piano and orchestra version, and piano solo version.

Description: Undoubtedly, Totentanz has been one of the most famous works by Franz Liszt. Totentanz has been recorded by many pianists and addressed in much of the vast literature about Liszt and his works; however, little research has been focused on this work. Most studies of Totentanz address only the historical background of the piece in relation to the theme based on Dies irae. Currently, there are no specific studies about the solo piano or two piano versions and only one recording was located. Liszt's own piano solo transcription of this famous work is an excellent addition to the concert repertoire. Totentanz consists of six variations that include canonic and fugato sections. The main theme is based on the Gregorian chant Dies irae, a melody that has been used by many other composers, most notably Berlioz in Witches Sabbath of Symphonie fantastique, op. 14 and Rachmaninoff in Rhapsody on a Theme of Paganini. This study contains five chapters. Chapters I and II provide background information, historical background and influences of Totentanz. Chapter III presents an outline of Liszt's achievement as a transcriber. Liszt revised his own works numerous times from the 1840s and 1850s, including Transcendental Etudes, Paganini Etudes, and piano and orchestra works. Like in the case of Totentanz, transcribed form piano and orchestra into piano solo, Liszt transcribed and paraphrased hundreds of other composers' works as well. Chapter IV discusses and compares the two main versions for solo piano and piano and orchestra. Form and harmonic language in particular the use of tritone in Totentanz is discussed. The adjustment required in transcribing the work for piano solo is discussed in detail, followed by a conclusion.
Date: December 2006
Creator: Kim, Min

A study of freshman interest groups and leadership practices at Texas Woman's University

Description: This study investigated the level of leadership practices and retention rates of freshman students at Texas Woman's University. The data for the study were collected using the Leadership Practices Inventory, Student Version. The sample for the study consisted of 151 freshman students. The students were each placed in one of three control groups. Group A students (the treatment group) were in the Neighbors Educated Together Program (NET). Group B students (control group) were in one of two university-sponsored programs (COLORS or University 1000), and Group C students (control group) were the residual group of first-time college freshmen. These three groups were surveyed prior to their participation in the NET program or a university-sponsored program and again at the end of 14 weeks. In addition, retention rates were examined on the 12 class day of the spring semester. The study found statistically significant differences (p <. 05) on the pretests and posttests between Group C, residual students, and the other two groups on the Enabling the Followers to Act subscale, the Inspiring a Shared Vision subscale, and Encouraging the Heart subscale. Group A, NET students, and Group B, COLORS/University 1000 students, showed no statistically significant differences between groups. The difference from the residual group could indicate that students who self-select into programs such as NET, COLORS, and University 1000 are more likely to engage in practices measured by the subscale prior to enrollment in the respective programs. No statistically significant differences were found on the Challenging the Process or Modeling the Way subscales. The lack of significance shows that there are no differences in practices for any of these groups prior to enrollment at the university or as a result of participation in a university-sponsored program such as NET, COLORS, or University 1000. A chi-square test was performed following the 12 ...
Date: August 2001
Creator: Mendez-Grant, Monica S

A Study of Graphically Chosen Features for Representation of TREC Topic-Document Sets

Description: Document representation is important for computer-based text processing. Good document representations must include at least the most salient concepts of the document. Documents exist in a multidimensional space that difficult the identification of what concepts to include. A current problem is to measure the effectiveness of the different strategies that have been proposed to accomplish this task. As a contribution towards this goal, this dissertation studied the visual inter-document relationship in a dimensionally reduced space. The same treatment was done on full text and on three document representations. Two of the representations were based on the assumption that the salient features in a document set follow the chi-distribution in the whole document set. The third document representation identified features through a novel method. A Coefficient of Variability was calculated by normalizing the Cartesian distance of the discriminating value in the relevant and the non-relevant document subsets. Also, the local dictionary method was used. Cosine similarity values measured the inter-document distance in the information space and formed a matrix to serve as input to the Multi-Dimensional Scale (MDS) procedure. A Precision-Recall procedure was averaged across all treatments to statistically compare them. Treatments were not found to be statistically the same and the null hypotheses were rejected.
Date: May 2000
Creator: Oyarce, Guillermo Alfredo

A Study of Perceptually Tuned, Wavelet Based, Rate Scalable, Image and Video Compression

Description: In this dissertation, first, we have proposed and implemented a new perceptually tuned wavelet based, rate scalable, and color image encoding/decoding system based on the human perceptual model. It is based on state-of-the-art research on embedded wavelet image compression technique, Contrast Sensitivity Function (CSF) for Human Visual System (HVS) and extends this scheme to handle optimal bit allocation among multiple bands, such as Y, Cb, and Cr. Our experimental image codec shows very exciting results in compression performance and visual quality comparing to the new wavelet based international still image compression standard - JPEG 2000. On the other hand, our codec also shows significant better speed performance and comparable visual quality in comparison to the best codec available in rate scalable color image compression - CSPIHT that is based on Set Partition In Hierarchical Tree (SPIHT) and Karhunen-Loeve Transform (KLT). Secondly, a novel wavelet based interframe compression scheme has been developed and put into practice. It is based on the Flexible Block Wavelet Transform (FBWT) that we have developed. FBWT based interframe compression is very efficient in both compression and speed performance. The compression performance of our video codec is compared with H263+. At the same bit rate, our encoder, being comparable to the H263+ scheme, with a slightly lower (Peak Signal Noise Ratio (PSNR) value, produces a more visually pleasing result. This implementation also preserves scalability of wavelet embedded coding technique. Thirdly, the scheme to handle optimal bit allocation among color bands for still imagery has been modified and extended to accommodate the spatial-temporal sensitivity of the HVS model. The bit allocation among color bands based on Kelly's spatio-temporal CSF model is designed to achieve the perceptual optimum for human eyes. A perceptually tuned, wavelet based, rate scalable video encoding/decoding system has been designed and implemented based on this ...
Date: May 2002
Creator: Wei, Ming

Style and the Art of Chaim Soutine: Ethnicity, Nationalism and Geography in the Critical Reception and Historiography

Description: This thesis argues that art criticism published during Soutine's lifetime emphasizes ethnicity, nationalism and geography in discussions of the artist's style. These critical discussions have influenced the historiography of Soutine published after his death, resulting in a continued emphasis on style that includes references to ethnicity. Ethnicity, nationalism and geography are identified in the critical reception and historiography by noting references, both specific and implied, to Jewishness, French art, and foreign status (among others). These references are analyzed in terms of existing scholarship that addresses concepts of ethnicity and nationalism, and with consideration to how the critical reception has impacted the historiography.
Date: August 2006
Creator: Grance, Heather Anne

Submerged wood inhabiting macoinvertebrates of the Elm Fork of the Trinity River, Texas: Assemblage analyses, comparisons to the benthic fauna, and a study of Cyrnellus fraternus (Trichoptera: Polycentropodidae)

Description: Taxonomic composition and spatio-temporal variability of macroinvertebrates inhabiting snags were examined from an 8-km segment of the Elm Fork of the Trinity River. Seventy-seven macroinvertebrate taxa were collected from submerged wood during the study. Assemblages were highly variable spatially and temporally, especially among seasons. An ordination of species and environment did not find snag taxa to have striking correlations with many of the selected environmental variables, although there were some trends in flow-mediated species distributions. There were significant seasonal differences in the abundances of some taxa, particularly among the Chironomidae (Diptera). The Tribe Orthocladiini was numerically abundant during the winter, while the Tribes Chironomini and Tanytarsini dominated the summer and autumn. Additionally, this study included a secondary production and microdistribution analysis of a population of the caddisfly Cyrnellus fraternus. Distributions of C. fraternus were restricted to snags, the most stable substratum for retreat building and for resisting periodic high waters. Larvae were not found in the soft sand and mud benthic habitats near submerged wood. The insects were multivoltine with a minimum of three generations per year. Pupae were collected July through September and adults emerged from May through October. The population overwintered as larvae. Estimated annual production was 1,015.4 mg/m2/yr. Mean standing stock biomass was 61.24 mg/m2, the cohort production/biomass ratio was 4.59, and the annual production/biomass rate was 16.58/yr for this population. Standing stock biomass ranged from 1.6 to 349.1 mg/m2 during the year and was significantly higher in autumn and summer than winter. Larvae were more abundant in the lower portions of the study area where flow was reduced for much of the year, than in the upper reaches, characterized by higher current velocities. C. fraternus larvae were found in their highest numbers on snags with dense deposits of silt and sand.
Date: August 2001
Creator: Johnson, Zane B.

Substituent Effects: A Computational Study on Stabilities of Cumulenes and Low Barrier Hydrogen Bonds

Description: The effect of substituents on the stabilities of cumulenes-ketenes, allenes, diazomethanes and isocyanates and related systems-alkynes, nitriles and nitrile oxides is studied using the density functional theory (B3LYP, SVWN and BP86) and ab initio (HF, MP2) calculations at the 6-31G* basis set level. Using isodesmic reactions, correlation between stabilization energies of cumulenes and substituent group electronegativities (c BE) is established and the results from DFT and MP2 methods are compared with the earlier HF calculations. Calculations revealed that the density functional methods can be used to study the effect of substituents on the stabilities of cumulenes. It is observed that the cumulenes are stabilized by electropositive substituent groups from s -electron donation and p -electron withdrawal and are destabilized by electronegative substituent groups from n-p donation. The calculated geometries of the cumulenes are compared with the available experimental data.High level ab initio and density functional theory calculations have been used to study the energetics of low-barrier hydrogen bond (LBHB) systems. Using substituted formic acid-formate anion complexes as model LBHB systems, hydrogen bond strength is correlated to the pKa mismatch between the hydrogen bond donor and the hydrogen bond acceptor. LBHB model systems are characterized by the 1H-NMR chemical shift calculations. A linear correlation between the calculated hydrogen bond strength and the predicted 1H-NMR chemical shift was established. It is concluded that the pKa matching within the enzyme active site of the two species involved in the LBHB is important to maximizing catalytic stabilization.
Date: August 2000
Creator: Kumar, Ganesh Angusamy

Supercritical Silylation and Stability of Silyl Groups

Description: Methylsilsesquioxane (MSQ) and organosilicate glass (OSG) are the materials under this study because they exhibit the dielectric constant values necessary for future IC technology requirements. Obtaining a low-k dielectric value is critical for the IC industry in order to cope time delay and cross talking issues. These materials exhibit attractive dielectric value, but there are problems replacing conventional SiO2, because of their chemical, mechanical and electrical instability after plasma processing. Several techniques have been suggested to mitigate process damage but supercritical silylation offers a rapid single repair step solution to this problem. Different ash and etch damaged samples were employed in this study to optimize an effective method to repair the low-k dielectric material and seal the surface pores via supercritical fluid processing with various trialkylchlorosilanes. Fourier transform infrared spectroscopy (FTIR), contact angle, capacitance- voltage measurements, and x-ray photoemission spectroscopy, dynamic secondary ion mass spectroscopy (DSIMS), characterized the films. The hydrophobicity and dielectric constant after exposure to elevated temperatures and ambient conditions were monitored and shown to be stable. The samples were treated with a series of silylating agents of the form R3-Si-Cl where R is an alkyl groups (e.g. ethyl, propyl, isopropyl). Reactivity with the surface hydroxyls was inversely proportional to the length of the alkyl group, perhaps due to steric effects. Contact angle measurements revealed that heating the films in ambient diminished hydrophobicity. Depth and surface profiling using (DSIMS) and (XPS) were utilized to develop a model for surface coverage.
Date: May 2006
Creator: Nerusu, Pawan Kumar

Supplemental Studies for Mastering Extended Techniques in Three Late Twentieth-Century Works for Solo Trombone: Luciano Berio's Sequenza V, Folke Rabe's Basta and Mark Phillips' T. Rex, Together with Three Recitals of Selected Works by Wagenseil, Grøndahl, Gotkovsky, and Others

Description: Many, if not most, student trombonists have perhaps had little or no previous experience with "extended techniques"-novel or unconventional modes of sound production. To address this deficiency of experience, this document sets forth a progressive sequence of descriptive explanations and supplementary studies, which are specifically designed to assist trombonists in mastering the particular extended techniques that will prepare them to perform three of the most popular late Twentieth-Century pieces for trombone that include extended techniques-Luciano Berio's Sequenza V, Folke Rabe's Basta, and Mark Phillips' T.Rex. Following the introductory chapter, the body of the document consists of three chapters, each of which deals with one of the three solos, presenting descriptive explanations of relevant extended techniques interspersed with performance commentary (solicited from prominent trombonists) and supplementary studies (composed by the author). The studies presented in each chapter are specifically geared toward mastering the extended techniques as they relate to the music of each particular solo. They are also especially focused toward learning the more difficult passages of music in each solo.
Date: May 2004
Creator: Scott, Deb

Suppressive effects of a stimulus correlated with reprimands for automatically-maintained eye poking.

Description: A functional analysis, conducted to assess the variables maintaining the chronic eye poking of a female diagnosed with profound mental retardation, indicated that the behavior persisted in the absence of social contingencies. A procedure was initiated in a training environment in which a punisher (mild reprimand) was delivered contingent on eye poking in the presence, but not in the absence, of a neutral stimulus (wristbands). Using a combination of multiple baseline and multielement experimental designs, it was determined that that eye poking was suppressed in the presence of the previously neutral stimulus, even in environments in which the reprimand contingency was inoperative.
Date: May 2003
Creator: McKenzie, Scott Daniel

Surface Plasmon Based Nanophotonic Optical Emitters

Description: Group- III nitride based semiconductors have emerged as the leading material for short wavelength optoelectronic devices. The InGaN alloy system forms a continuous and direct bandgap semiconductor spanning ultraviolet (UV) to blue/green wavelengths. An ideal and highly efficient light-emitting device can be designed by enhancing the spontaneous emission rate. This thesis deals with the design and fabrication of a visible light-emitting device using GaN/InGaN single quantum well (SQW) system with enhanced spontaneous emission. To increase the emission efficiency, layers of different metals, usually noble metals like silver, gold and aluminum are deposited on GaN/InGaN SQWs using metal evaporator. Surface characterization of metal-coated GaN/InGaN SQW samples was carried out using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Photoluminescence is used as a tool for optical characterization to study the enhancement in the light emitting structures. This thesis also compares characteristics of different metals on GaN/InGaN SQW system thus allowing selection of the most appropriate material for a particular application. It was found out that photons from the light emitter couple more to the surface plasmons if the bandgap of former is close to the surface plasmon resonant energy of particular metal. Absorption of light due to gold reduces the effective mean path of light emitted from the light emitter and hence quenches the quantum well emission peak compared to the uncoated sample.
Date: December 2005
Creator: Vemuri, Padma Rekha

Surface Topography and Aesthetics of Recycled Cross-Linked Polyethylene Wire and Cable Coatings

Description: Our research focuses on re-using a waste a material, cross-linked polyethylene abbreviated XLPE, which is a widely used coating for wires. XLPE is strong and has excellent thermal properties due to its chemical structure - what leads to the significance of recycling this valuable polymer. Properties of XLPE include good resistance to heat, resistance to chemical corrosion, and high impact strength. A wire is usually composed of a metal core conductor and polymeric coating layers. One creates a new coating, including little pieces of recycled XLPE in the lower layer adjacent to the wire, and virgin XLPE only in the upper layer. Industries are often wasting materials which might be useful. Mostly, some returned or excess products could be recycled to create a new type of product or enable the original use. This method helps cleaning the waste, lowers the costs, and enhances the income of the manufacturing company. With the changing of the thickness of the outer layer, the roughness changes significantly. Moreover, different processing methods result in surfaces that look differently.
Date: December 2014
Creator: Xie, Wa

Survey of Texas Public Universities and University Systems Involvement in State Public Policy Making

Description: This study investigated the perceptions of influential relationships between Texas public university presidents, university system chancellors, and state legislators. The study's purpose was to examine Texas public universities engagement in lobbying type behaviors and whether public policy is affected through interaction and communication with legislative leaders. Moreover, of importance for this study was to identifying if Texas public universities actively work to influence the Texas legislature and if lobbying behavior exists whether or not that behavior influences public policy formation within the Texas legislative process. Lastly, this study focused on perceptions dealing with the Texas statute prohibiting state governmental agencies, including public universities and university systems, from influencing legislation through use of state funds. The study was conducted in the winter of 2003 and had 29 president / chancellor respondents and 88 legislator respondents. Three survey instruments were developed by the researcher to determine Texas public university president, system chancellor, and state legislator perceptions and attitudes concerning lobbying type activities, influence, and state statute compliance. Data reported consist of percentages, t-Test of significance, and Cohen's d effect size measure. Results from the study show agreement between the groups in areas of activities utilized to influence the legislative process and actual influence of public policy. Disagreement within statute compliance was reported between the groups.
Date: August 2004
Creator: Wolf, David Fletcher

Sustainable Ecofriendly Insulation Foams for Disaster Relief Housing

Description: Natural disasters are affecting a significant number of people around the world. Sheltering is the first step in post-disaster activities towards the normalization of the affected people's lives. Temporary housing is being used in these cases until the construction of permanent houses are done. Disposal of temporary housing after use is leading to a significant environmental impact because most of them are filled with thermally insulative polymer foams that do not degrade in a short period. To reduce these problems this work proposes to use foams made with compostable thermoplastic polylactic acid (PLA) and degradable kenaf core as filler materials; these foams are made using CO2 as blowing agent for insulation purposes. Foams with PLA and 5%, 10% and 15% kenaf core were tested. Different properties and their relations were examined using differential scanning calorimetry (DSC), thermal conductivity, mechanical properties, scanning electron microscopy (SEM), x-ray μ-computed tomography (μ-CT) and building energy simulations were done using Energy Plus by NREL. The results show that mechanical properties are reduced with the introduction of kenaf core reinforcement while thermal conductivity display a noticeable improvement.
Date: May 2017
Creator: Chitela, Yuvaraj R

The Symbolic Representation of Latinos: A Content Analysis of Prime-Time Television

Description: The media are powerful agents of socialization in modern society influencing values, beliefs, and attitudes of the culture that produces them. Both the quantity and quality of Latino images in the media may reflect and reinforce the place of Latinos in United States society. This study examines how Latinos are portrayed in television entertainment programming by addressing two major research questions: 1) What is the extent of Latino recognition on prime-time television? and 2) What is the extent of respect accorded Latinos on prime-time television? A one-week sample of prime-time television programming airing on three networks yielded 47 programs and 807 characters for analysis. Using content analysis methodology, recognition is identified by examining the frequency and proportional representation of Latino television portrayals and respect is measured by examining the types and significance of these roles. The results indicate an overall lack of diversity on prime-time television with only 11 of the 47 programs analyzed reaching 50% or more of the maximum possible diversity in their racial and ethnic portrayals. Specifically, Latinos represent only 3% of primetime television characters, less than one-fourth of their proportion of the nation's population. Compared to non-Hispanic Whites, Blacks, and Asians, Latinos are the group least likely to occupy major roles in prime-time entertainment shows and represent only 1.9% of the total opening cast credits. Latinos are still presented stereotypically but are more often presented in a generic fashion with no reference to ethnic cultural experiences. The extent of recognition and respect accorded Latinos in prime-time television is severely limited, thus there is a need for continued research and dialogue regarding symbolic media images of Latinos. The findings have implications for social scientists interested in media forms and content as cultural artifacts, members of the television media industry responsible for program development and distribution, and college ...
Date: August 2001
Creator: McKenzie-Elliott, Tracey M.

Symmetrical Features of Nikolai Medtner's Language: The Grzovaya Sonata, Opus 53 No. 2

Description: Nikolai Medtner's works evidence an intense interest in symmetrical designs. This concern is manifest at all levels, from the large scale proportions of his numerous ingenious sonata forms to the symmetrically constructed themes and motives. Medtner's works include several instances of palindromic themes and periods. Some palindromic contours are achieved through immediate inversion, creating expansive, symmetrical waves. One of Medtner's thumbprints, symmetrical contrary voice-leading, consists of two or more voices which systematically expand or contract in exact mirror fashion. The contrary movement is usually stepwise, and may be either chromatic or diatonic. Occasionally even larger intervals, such as thirds and fourths, are subjected to this favourite mirroring technique. Such symmetrical expansion and contraction often controls the harmonic progression of several consecutive bars. One of the most striking aspects of Medtner's music is his sophisticated harmonic language. He was fascinated with symmetrical harmonic designs, such as the tritone, the French sixth chord, and the octatonic scale, and made endless and increasingly intricate explorations into these stuctures and the ways in which these apparently nontonal, non-hierarchical forms could be coordinated with the fundamental hierarchy of asymmetrical tonal forms, including triads, major and minor scales, and tonic-dominant relations. Medtner's late work, the Grozovaya Sonata, Opus 53 No.2, is the most concentrated and abstract of his works. The themes are built from highly lapidar motives, giving this work an intensely angular, rigorously mathematical character. All the symmetrical hallmarks of Medtner's language are in abundant evidence in this great work. Features include the extensive symmetrical mirroring of the opening section, frequent use of contrary voice leading as a generator of harmonic progression, and constant tritone shifting. Medtner also builds sequential chains based on two more symmetrical forms, the diminished seventh and the augmented triad. Finally, the design of this unique single movement sonata may be ...
Date: December 1999
Creator: Pitts, James L.

Synchrotron Radiation X-Ray Diffraction of Nickel-Titanium Shape Memory Alloy Wires during Mechanical Deformation

Description: Shape memory alloys (SMAs) are a new generation material which exhibits unique nonlinear deformations due to a phase transformation which allows it to return to its original shape after removal of stress or a change in temperature. It shows a shape memory effect (martensitic condition) and pseudoelasticity (austenitic condition) properties depends on various heat treatment conditions. The reason for these properties depends on phase transformation through temperature changes or applied stress. Many technological applications of austenite SMAs involve cyclical mechanical loading and unloading in order to take advantage of pseudoelasticity, but are limited due to poor fatigue life. In this thesis, I investigated two important mechanical feature to fatigue behavior in pseudoelastic NiTi SMA wires using high energy synchrotron radiation X-ray diffraction (SR-XRD). The first of these involved simple bending and the second of these involved relaxation during compression loading. Differential scanning calorimetry (DSC) was performed to identify the phase transformation temperatures. Scanning electron microscopy (SEM) images were collected for the initial condition of the NiTi SMA wires and during simple bending, SEM revealed that micro-cracks in compression regions of the wire propagate with increasing bend angle, while tensile regions tend to not exhibit crack propagation. SR-XRD patterns were analyzed to study the phase transformation and investigate micromechanical properties. By observing the various diffraction peaks such as the austenite (200) and the martensite (100), (110), and (101) planes, intensities and residual strain values exhibit strong anisotropy depending upon whether the sample is in compression or tension during simple bending. This research provides insight into two specific mechanical features in pseudoelastic NiTi SMA wires.
Date: December 2015
Creator: Zhang, Baozhuo

Synthesis and Characterization of Crystalline Assemblies of Functionalized Hydrogel Nanoparticles

Description: Two series monodispersed nanoparticles of hydroxylpropyl cellulose (HPC) and functionalized poly-N-isopropylamide (PNIPAM) particles have been synthesized and used as building blocks for creating three-dimensional networks, with two levels of structural hierarchy. The first level is HPC nanoparticles were made from methacrylated or degradable cross-linker attached HPC. These nanoparticles could be stabilized at room temperature by residual methacrylate or degradable groups are present both within and on the exterior of HPC nanoparticles. Controlled release studies have been performed on the particle and networks .The nearly monodispersed nanoparticles have been synthesized on the basis of a natural polymer of hydropropylcellulose (HPC) with a high molecular weight using the precipitation polymerization method and self-assembly of these particles in water results in bright colors. The HPC nanoparticles can be potential using as crosslinkers to increase the hydrogels mechanical properties, such as high transparency and rapid swelling/de-swelling kinetics. The central idea is to prepare colloidal particles containing C=C bonds and to use them as monomers - vinylparticles, to form stable particle assemblies with various architectures. This is accomplished by mixing an aqueous suspension of hydrogel nanoparticles (PNIPAM-co-allylamine) with the organic solvent (dichloromethane) to grow columnar crystals. The hydrogels with such a unique crystal structure behavior not only like the hydrogel opals, but also have a unique property: anisotropy.
Date: December 2005
Creator: Cai, Tong

Synthesis and characterization of quinoxaline-functionalized, cage-annulated oxa- and thiacrown ethers and reaction chemistry of the diphosphine ligand 2,3-bis(diphenylphosphino)-N-p-tolylmaleimide (bmi) at triosmium carbonyl clusters.

Description: Quinoxaline-functionalized, cage-annulated oxa- and thiacrown ethers have been synthesized as possible specific metal host systems. The synthesis and characterization of quinoxaline-functionalized, cage-annulated oxa- and thiacrown ethers have been described. The characterization of these host systems have been fully achieved in solution by using various techniques such as IR, 1H NMR, and 13C NMR spectroscopic methods, high-resolution mass spectrometry (HRMS), elemental microanalysis, and X-ray crystallographic analysis in case of one quinoxaline-functionalized, cage-annulated oxacrown ether compound. The synthesis of the diphosphine ligand 2,3-bis(diphenylphosphino)-N-p-tolylmaleimide (bmi) is described. The substitution of the MeCN ligands in the activated cluster 1,2-Os3(CO)10(MeCN)2 by the diphosphine ligand bmi proceeds rapidly at room temperature to furnish a mixture of bridging and chelating Os3(CO)10(bmi) isomers and the ortho-metalated product HOs3(CO)9[μ-(PPh2)C=C{PPh(C6H4)}C(O)N(tolyl-p)C(O)]. Thermolysis of the bridging isomer 1,2-Os3(CO)10(bmi) under mild conditions gives the chelating isomer 1,1-Os3(CO)10(bmi), whose molecular structure has been determined by X-ray crystallography. The kinetics for the ligand isomerization have been investigated by UV-vis and 1H NMR spectroscopy in toluene solution over the temperature range of 318-348 K. On the basis of kinetic data conducted in the presence of added CO and the Eyring activation parameters, a non-dissociative phosphine migration across one of the Os-Os bonds is proposed. Orthometalation of one of the phenyl groups associated with the bmi ligand is triggered by near-UV photolysis of the chelating cluster 1,1- Os3(CO)10(bmi).
Date: December 2006
Creator: Poola, Bhaskar