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Additive Manufacturing of Metastable Beta Titanium Alloys

Description: Additive manufacturing processes of many alloys are known to develop texture during the deposition process due to the rapid reheating and the directionality of the dissipation of heat. Titanium alloys and with respect to this study beta titanium alloys are especially susceptible to these effects. This work examines Ti-20wt%V and Ti-12wt%Mo deposited under normal additive manufacturing process parameters to examine the texture of these beta-stabilized alloys. Both microstructures contained columnar prior beta grains 1-2 mm in length beginning at the substrate with no visible equiaxed grains. This microstructure remained constant in the vanadium system throughout the build. The microstructure of the alloy containing molybdenum changed from a columnar to an equiaxed structure as the build height increased. Eighteen additional samples of the Ti-Mo system were created under different processing parameters to identify what role laser power and travel speed have on the microstructure. There appears to be a correlation in alpha lath size and power density. The two binary alloys were again deposited under the same conditions with the addition of 0.5wt% boron to investigate the effects an insoluble interstitial alloying element would have on the microstructure. The size of the prior beta grains in these two alloys were reduced with the addition of boron by approximately 50 (V) and 100 (Mo) times.
Date: August 2017
Creator: Yannetta, Christopher James

Application of UV-Vis Spectroscopy to the Monitoring, Characterization and Analysis of Chemical Equilibria of Copper Etching Baths

Description: The continuously increasing demand for innovation in the miniaturization of microelectronics has driven the need for ever more precise fabrication strategies for device packaging, especially for printed circuit boards (PCBs). Subtractive copper etching is a fundamental step in the fabrication process, requiring very precise control of etch rate and etch factor. Changes in the etching chemical equilibrium have significant effects on etching behavior, and CuCl2 / HCl etching baths are typically monitored with several parameters including oxidation-reduction potential, conductivity, and specific gravity. However, the etch rate and etch factor can be difficult to control even under strict engineering controls of those monitoring parameters. The mechanism of acidic cupric chloride etching, regeneration and recovery is complex, and the current monitoring strategies can have difficulty controlling the interlocking chemical equilibria. A complimentary tool, thin-film UV-Vis spectroscopy, can be utilized to improve the current monitoring strategies, as UV-Vis is capable of identifying and predicting etching behavior that the current standard methodologies have difficulty predicting. Furthermore, as a chemically-sensitive probe, UV-Vis can investigate the complex changes to the chemical equilibrium and speciation of the etch bath, and can contribute overall to significant improvements in the control of the copper etching system in order to meet the demands of next-level design strategies.
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Date: August 2017
Creator: Lambert, Alexander S

Are Streams Protected? Outcomes of Environmental Regulation

Description: Urban areas experience the loss of natural stream channels through conversion to artificial conveyances. This process tends to target headwater and other low order streams. The purpose of this study is to determine the patterns of stream loss in Denton, Texas, and explore the regulatory structure that manages these streams. Historic and current maps and stream data are used to map Denton's streams and categorize them according to their vertical connectivity as: 1) "intact", streams that are open to the atmosphere and connect to groundwater; 2) "concrete", channelized streams open to the atmosphere but cut off from groundwater; and 3) "buried", streams disconnected from the atmosphere and groundwater. A review of federal, state, and local regulatory codes and interviews with local government officials and other stakeholders elucidates stream management in Denton. Results from these analyses reveal high rates of stream loss in the urban center with low rates overall. The federal Clean Water Act and the local Environmentally Sensitive Areas code serve as the primary protective measures for natural streams. These regulations discourage stream impacts through expensive and complex permitting requirements. However the policies allow minor impacts which may cause cumulative effects. This study aims to inform future policy-making decisions and contribute to the knowledge of the environmental regulation of streams.
Date: August 2017
Creator: Rowen, Zachary

Best Practices in Targeted Advertising for Fashion Entrepreneurs

Description: A key to a business's success is reaching the target market. This ensures that consumers are exposed to the retailer's offerings and by turn, inspired to purchase. In turn, the business can reach its goal of a profitable organization. The purpose of this paper was to determine the most effective fashion advertising appeals for reaching target markets. To address these issues, this thesis consisted of two studies. The purpose of the first study was to determine the advice given to fashion entrepreneurs regarding effective target market practices. The purpose of the second study was to determine effective advertising strategies fashion entrepreneurs may employ for effectively reaching target markets. Data was collected to test the effectiveness of the advice from Study 1, degrees of brand awareness, attitudes towards advertising, willingness to follow trends, purchase intention, purchase behavior, and shopping involvement. The Theory of Reasoned Action was employed as the theoretical framework of the study. The framework was utilized to predict that attitudes towards targeted advertising and pressure to follow fashion trends would positively relate to intent to purchase which, in turn, would positively relate to purchase behavior. The results of this paper concluded the TRA model provided a proper framework to predict purchase behavior from targeted advertising employed by fashion entrepreneurs.
Date: August 2017
Creator: Slaton, Kelcie Shaelyn

BLE Controller Module for Wireless Sensor Networks

Description: Sensors have been an integral part of our life since a long time. Traditionally, the transmit information to a data collection center through a physical wire. However, with the introduction of Bluetooth Low Energy (BLE) communication protocol, more research is being done into the field of wireless sensor networks (WSN). BLE was introduced to target low power applications. The CC2650 Launchpad designed by Texas Instruments (TI) can lead to a bulky final product. The aim was to design hardware for the CC2650 micro-controller with the aim of making it more compact for use in WSNs. A top-down approach was used wherein the available product is studied to identify the redundant and reverse engineer it to design a new product. A 2 layer printed circuit board (PCB) was designed which resulted in a 64 percent decrease in size compared to the Launchpad. Also, experiments were performed to test the proof of concept.
Date: August 2017
Creator: Vaswani, Mohit Suresh

A Conjugate Arrangement for Measuring Commercial Viewing

Description: Commercial viewing was measured by a conjugate arrangement for 1 female and 3 male participants. Reinforcing qualities were evaluated according to screen variations and ratings. Subjects changed the screen clarity via knob pressing either making the screen more or less transparent, translucent or opaque based on commercial interest. Results were conducive to participant attentiveness or indifference to commercial viewing. Experimenter was able to identify the commercials that grasped and maintained the participants' viewing behavior. Conceptually this conjugate arrangement could enhance eye tracking technology to improve marketing and advertising strategies. This experiment yield results that suggest a more concrete analysis of consumer response to visual stimuli that maintains attending.
Date: August 2017
Creator: Morgan, Amber

A Convergence of LDPC Based on Eigenvalues

Description: Low-density parity check (LDPC) codes are very popular among error correction codes because of their high-performance capacity. Numerous investigations have been carried out to analyze the performance and simplify the implementation of LDPC codes. Relatively slow convergence of iterative decoding algorithm affects the performance of LDPC codes. Faster convergence can be achieved by reducing the number of iterations during the decoding process. In this thesis, a new approach for faster convergence is suggested by choosing a systematic parity check matrix that yields lowest Second Smallest Eigenvalue Modulus (SSEM) of its corresponding Laplacian matrix. MATLAB simulations are used to study the impact of eigenvalues on the number of iterations of the LDPC decoder. It is found that for a given (n, k) LDPC code, a parity check matrix with lowest SSEM converges quickly as compared to the parity check matrix with high SSEM. In other words, a densely connected graph that represents the parity check matrix takes more iterations to converge than a sparsely connected graph.
Date: August 2017
Creator: Kharate, Neha Ashok

Cultural Humility, Religion, and Health in Lesbian, Gay, and Bisexual (LGB) Populations

Description: The purpose of this study was to explore the religion – health link in a sample of adults and undergraduate students (N = 555) that identified as lesbian, gay, or bisexual (LGB), and to explore how perceptions of cultural humility of religious individuals and groups toward LGB individuals affect the relationship between religion and health. First, I found religious commitment among LGB individuals was positively correlated with satisfaction in life, but it was negatively correlated with physical health. Second, I found that cultural humility moderated the relationship between religious commitment and satisfaction in life for LGB individuals involved in a religious community. The lowest levels of satisfaction with life were found for individuals with low religious commitment and perceived the cultural humility of their religious community to be low. However, cultural humility did not moderate the relationship between religious commitment and mental and physical health outcomes. Third, I found cultural humility did not moderate the relationship between religious commitment and minority stress (i.e., internalized homophobia). Fourth, I found that cultural humility was a significant positive predictor of motivations to forgive a hurt caused by a religious individual. I conclude by discussing limitations, areas for future research, and implications for counseling.
Date: August 2017
Creator: Mosher, David Keith

A Decision-Making Model for Safe and Effective Use of Functional Analysis Procedures

Description: While functional analysis provides the standard methodology for the assessment of problem behavior, procedures still pose potential risk when assessing severe problem behavior. Previous studies have examined several strategies to improve the efficiency of and reduce risks related to the functional analysis process. The purpose of the present series of studies was to replicate and extend previous research on the assessment and treatment of severe problem behavior for one participant diagnosed with an intellectual disability. By incorporating strategies within a systematic decision-making framework, functional analysis procedures were implemented to conduct the assessment of precursors, determine maintaining contingencies for severe problem behavior, and evaluate the effects of a treatment based on the results of a functional analysis.
Date: August 2017
Creator: Vega, Gabrielle M.

Delivery of CRISPR/Cas9 into Blood Cells of Zebrafish: Potential for Genome Editing in Somatic Cells

Description: Factor VIII is a clotting factor found on the intrinsic side of the coagulation cascade. A mutation in the factor VIII gene causes the disease Hemophilia A, for which there is no cure. The most common treatment is administration of recombinant factor VIII. However, this can cause an immune response that renders the treatment ineffective in certain hemophilia patients. For this reason a new treatment, or cure, needs to be developed. Gene editing is one solution to correcting the factor VIII mutation. CRISPR/Cas9 mediated gene editing introduces a double stranded break in the genomic DNA. Where this break occurs repair mechanisms cause insertions and deletions, or if a template oligonucleotide can be provided point mutations could be introduced or corrected. However, to accomplish this goal for editing factor VIII mutations, a way to deliver the components of CRISPR/Cas9 into somatic cells is needed. In this study, I confirmed that the CRISPR/Cas9 system was able to create a mutation in the factor VIII gene in zebrafish. I also showed that the components of CRISPR/Cas9 could be piggybacked by vivo morpholino into a variety of blood cells. This study also confirmed that the vivo morpholino did not interfere with the gRNA binding to the DNA, or Cas9 protein inducing the double stranded break.
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Date: August 2017
Creator: Schneider, Sara Jane

Development and Analysis of a Mobile Node Tracking Antenna Control System

Description: A wireless communication system allows two parties to exchange information over long distances. The antenna is the component of a wireless communication system that allows information to be converted into electromagnetic radiation that propagates through the air. A system using an antenna with a highly directional beam pattern allows for high power transmission and reception of data. For a directional antenna to serve its purpose, it must be accurately pointed at the object it is communicating with. To communicate with a mobile node, knowledge of the mobile node's position must be gained so the directional antenna can be regularly pointed toward the moving target. The Global Positioning System (GPS) provides an accurate source of three-dimensional position information for the mobile node. This thesis develops an antenna control station that uses GPS information to track a mobile node and point a directional antenna toward the mobile node. Analysis of the subsystems used and integrated system test results are provided to assess the viability of the antenna control station.
Date: August 2017
Creator: Hensley, Phillip Hayden

Development and Validation of Measures of Generalization of a Behavior Management Package

Description: In order for the benefits of a behavior management skills training program to reach clients, caregivers must use the behavior management skills in the natural environment. The current study took place at a large residential facility for adults with disabilities, in which caregivers had received prior training in which they demonstrated behavior management skills and maintained those skills in contrived role plays. The current study represents a preliminary analysis of generalization of these skills in the natural environment; thus, a measurement system for when caregivers should demonstrate the tools was developed. The specific purpose of this study was to develop and evaluate a program to establish stimulus control over observers' measurement of appropriate behaviors. Researchers systematically developed and validated a measurement system of "good behaviors" that could be used across clients. The process of development and refinement of the measurement system is described. When the system was finalized, three observers' accuracy in using the system was assessed by comparing measured values to that of the code writer. Following feedback on individual instances of behavior, all observers scored the three target behaviors accurately. Ecological validity was assessed by surveying professionals at the facility and ecological validity results suggested a valid measurement system was developed.
Date: August 2017
Creator: Speckin, Lauren Marie

Development of a Natural Fiber Mat Plywood Composite

Description: Natural fibers like kenaf, hemp, flax and sisal fiber are becoming alternatives to conventional petroleum fibers for many applications. One such applications is the use of Non-woven bio-fiber mats in the automobile and construction industries. Non-woven hemp fiber mats were used to manufacture plywood in order to optimize the plywood structure. Hemp fiber mats possess strong mechanical properties that comparable to synthetic fibers which include tensile strength and tensile modulus. This study focuses on the use of hemp fiber mat as a core layer in plywood sandwich composite. The optimization of fiber mat plywood was done by performing a three factor experiment. The three factors selected for this experiment were number of hemp mat layers in the core, mat treatment of the hemp mat, and the glue content in the core. From the analysis of all treatments it was determined that single hemp mat had the highest effect on improving the properties of the plywood structure.
Date: August 2017
Creator: Anthireddy, Prasanna Kumar

Development of a Targeted Protein Residue Analysis Approach in Archaeology

Description: Liquid chromatography-mass spectrometry (LC-MS) based proteomic methods have provided archaeologists with a powerful tool for the discovery and identification of proteins within artifacts. Traditionally, discovery-based methods have utilized a non-targeted full mass scan method in an attempt to identify all proteins present within a given sample. However, increased sensitivity is often needed to target specific proteins in order to test hypotheses. Proteins present within archaeological materials present a unique challenge, as they are often subjected to a variety of chemical transformations both before and after burial. Any preserved proteins will be present within a complex mixture of compounds, and full mass scans often fail to detect less abundant proteins of interest. Consistent and reliable targeted methods are needed to detect protein biomarkers. Taphonomic experimentation was employed as a means to identify the effect of particular processes and conditions on the preservation of mare's milk proteins. In addition, three LC-MS methods were evaluated for their efficiency in identifying mare's milk-specific peptide biomarkers from experimental pottery samples. The ability to reliably detect the presence of these species-specific peptides can help provide evidence about past cultural groups, including the origins of dairying and animal domestication.
Date: August 2017
Creator: Scott, Ashley

Dynamic Screening via Intense Laser Radiation and Its Effects on Bulk and Surface Plasma Dispersion Relations

Description: Recent experimentation with excitation of surface plasmons on a gold film in the Kretschmann configuration have shown what appears to be a superconductive effect. Researchers claimed to see the existence of electron pairing during scattering as well as magnetic field repulsion while twisting the polarization of the laser. In an attempt to explain this, they pointed to a combination of electron-electron scattering in external fields as well as dynamic screening via intense laser radiation. This paper expands upon the latter, taking a look at the properties of a dynamic polarization function, its effects on bulk and surface plasmon dispersion relations, and its various consequences.
Date: August 2017
Creator: Lanier, Steven t

Effect of Surface Treatment on the Performance of CARALL, Carbon Fiber Reinforced Aluminum Joints

Description: Fiber-metal laminates (FML) are the advanced materials that are developed to improve the high performance of lightweight structures that are rapidly becoming a superior substitute for metal structures. The reasons behind their emerging usage are the mechanical properties without a compromise in weight other than the traditional metals. The bond remains a concern. This thesis reviews the effect of pre-treatments, say heat, P2 etch and laser treatments on the substrate which modifies the surface composition/roughness to impact the bond strength. The constituents that make up the FMLs in our present study are the Aluminum 2024 alloy as the substrate and the carbon fiber prepregs are the fibers. These composite samples are manufactured in a compression molding process after each pre-treatment and are then subjected to different tests to investigate its properties in tension, compression, flexural and lap shear strength. The results indicate that heat treatment adversely affects properties of the metal and the joint while laser treatments provide the best bond and joint strength.
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Date: August 2017
Creator: Bandi, Raghava

Eggplant Emoji

Description: Eggplant Emoji is a documentary film that reveals a range of feminist perspectives on dick pics, sexting and online sexual harassment. Through intimate and hilarious interviews with women between the ages of 22 and 35, the film harnesses a collective voice that speaks back to the large and small ways patriarchy wields power in modern spaces, especially through sending unsolicited dick pics. By intertwining the testimonies of a dynamic group of female storytellers sitting amongst their close friends, the film provides candid and diverse commentary on this unique moment we are in, where the lines between private and public, online and offline are increasingly blurred. Until there are greater consequences, whether legal, social or otherwise, for men disrespecting women's choices and personal space, the domain of sexting is in a self-policing state and women are left to expend emotional labor to let men know why what they sent is unwanted or violating. Ultimately, the subjects' testimonials coalesce to provide suggestions for respectful, consensual sexting practices and fill in the gaps where sex education often neglects the importance of consent and communication altogether.
Date: August 2017
Creator: Warncke, Nicole

Electrochemical Deposition of Nickel Nanocomposites in Acidic Solution for Increased Corrosion Resistance

Description: The optimal conditions for deposition of nickel coating and Ni-layered double hydroxide metal matrix composite coatings onto stainless steel discs in a modified all-sulfate solutions have been examined. Nickel films provide good general corrosion resistance and mechanical properties as a protective layer on many metallic substrates. In recent years, there has been interest in incorporation nano-dimensional ceramic materials, such as montemorillonite, into the metal matrices to improve upon the corrosion and mechanical properties. Layered double hydroxides have been used as corrosion enhancer in polymer coatings by increasing mechanical strength and lowering the corrosion rate but until now, have not been incorporated in a metal matrix by any means. Layered double hydroxides can be easily synthesized in a variety of elemental compositions and sizes but typically require the use of non-polar solvents to delaminate into nanodimensional colloidal suspensions. The synthesis of a Zn-Al LDH has been studied and characterized. The effects of the non-polar solvents dimethylformamide and n-butanol on the deposition and corrosion resistance of nickel coatings from a borate electrolyte bath have been studied, a nickel-LDH nanocomposite coating has been synthesized by electrochemical deposition and the corrosion resistance has been studied. Results indicate an improvement in corrosion resistance for the coatings with minimal change in the nickel matrix's internal strain and crystallite size.
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Date: August 2017
Creator: Daugherty, Ryan E.

An Engagement Bout Analysis of the Effects of Effort

Description: Operant response rate can be viewed as bouts, periods of alternating engagement and disengagement with ongoing schedules of reinforcement. Relatively few studies have examined the role of force and effort on engagement bouts. Moreover, those examining effort have used switch closure devices to define the response. Switch closures tend to overestimate the effect of effort because increasing the force requirement excludes low-force responses that previously activated the switch. In the present study, we examined the effects of effort using a force transducer, which allows us to record criterion responses that meet the force requirement and subcriterion responses that do not. The current study was conducted using four male Sprague Dawley rats. Each rat was run through a series of four conditions, each with a different combination of variable interval schedules (VI 30s, VI 120s) and force requirements (5.6g, 32g). Log survivor analyses of bout structure showed that increased force requirements decreased the rate of bout initiations. Additionally, when log-survivor functions were computed using only criterion responses, shifts in the function were less extreme than when all measured responses were used; the latter finding suggests exclusion of "subcriterion" responses in prior work has overestimated the effects of force on bout structure
Date: August 2017
Creator: Moore, Alyssa Nicole

Evaluating the Role of UV Exposure and Recovery Regimes in PAH Photo-Induced Toxicity

Description: Polyaromatic hydrocarbons (PAHs) are contaminants synthesized through incomplete combustion of carbon based substances. PAHs are known to be photodynamic and toxicity increases exponentially when in contact with ultraviolet radiation (UV). The effect of UV absent recovery periods and potential for latent toxicity during photo-induced toxicity are previously unknown and are not included within the toxicity model. Results of equal interval tests further support the current reciprocity model as a good indicator of PAH photo-induced toxicity. Interval test results also indicate a possible presence of time-dependent toxicity and recovery thresholds and should be included into toxicity risk assessments. Moreover, results of latent effects assays show that latent mortality is a significant response to PAH photo-induced toxicity and should be included into toxicity risk assessments. The present research demonstrates that UV exposure time rate is a significant driving force of PAH photo-induced toxicity.
Date: August 2017
Creator: Gnau, Jennifer Leigh

Formation Control of Multi-Agent Systems

Description: Formation control is a classical problem and has been a prime topic of interest among the scientific community in the past few years. Although a vast amount of literature exists in this field, there are still many open questions that require an in-depth understanding and a new perspective. This thesis contributes towards exploring the wide dimensions of formation control and implementing a formation control scheme for a group of multi-agent systems. These systems are autonomous in nature and are represented by double integrated dynamics. It is assumed that the agents are connected in an undirected graph and use a leader-follower architecture to reach formation when the leading agent is given a velocity that is piecewise constant. A MATLAB code is written for the implementation of formation and the consensus-based control laws are verified. Understanding the effects on formation due to a fixed formation geometry is also observed and reported. Also, a link that describes the functional similarity between desired formation geometry and the Laplacian matrix has been observed. The use of Laplacian matrix in stability analysis of the formation is of special interest.
Date: August 2017
Creator: Mukherjee, Srijita

Generating Molecular Biology Tools to Investigate the Ca2+ Binding Ability of Arabidopsis TON2

Description: The position of the cell division plane in plants is determined by the position of the preprophase band. The pre prophase band (PPB) is a ring of microtubules centered around the nucleus on the inner side of plasma membrane that establishes the cortical division site. The PPB forms at the end of G2 and breaks down at the end of prophase leaving behind protein markers of its position that are collectively called the cortical division site. During cytokinesis the phragmoplast expands towards the cortical division site and mediates the fusion of the new cell plate with the mother cell at that position. Several proteins necessary for PPB formation in plants have been identified, including maize DCD1 and ADD1 and Arabidopsis TON2, which are all type 2A protein phosphatase (PP2A)B" regulatory subunits. DCD1, ADD1, and TON2 localize to the PPB and the cortical division site through metaphase. The PP2A subunits each have two EF-hand domains, which are predicted to bind calcium ions. Since calcium ions are important for some aspects of cell division, we designed a series of constructs to test if TON2 binds calcium. TON2 protein was cloned into expression vectors, pET42a, and expression of TON2 protein was confirmed via Western blotting and immunodetection using a GST antibody. Site directed mutagenesis was used to mutate the TON2 EF-hand domains and mutated cDNAs were also cloned into expression vectors. These were then expressed in bacterial systems. Finally, the GST tagged proteins were purified. In the future, wild-type and mutated proteins TON2 proteins will used in calcium binding assays to determine if TON2 binds calcium.
Date: August 2017
Creator: Shao, Danyang