This thesis presents an analysis of data based on the results of a previous study into the path independence of friction stir welding (FSW). The original study was conducted in two phases using AA2024 and AA2198 aluminum alloy material. In Phase I, welds were made with six different tool designs, and tensile data was entered into Statgraphics® software as part of a design of experiments (DOE) approach for the purpose of optimizing the weld parameter process windows for each tool design. Phase II included a round robin study where welds were produced at four sites to evaluate site-to-site variability. In the present study, testing of the welds included additional tensile testing, full-field microhardness testing, and conductivity testing of the welds produced in the prior two phases of the program. The welds were inspected for defects, and the method of failure on the tensile specimens is discussed. Tensile data was evaluated statistically using Statgraphics® software. Previously, as part of Phase I, that data was evaluated using the techniques of chapter nine of the Metallic Materials Properties Development and Standardization (MMPDS), and design allowables were calculated at that time. In the present study, Phase II data was compared using the design allowables from Phase I. Variability was not found to be significant when evaluated according to location of the tensile coupon along the weld joint line or as a function of weld parameters in the process window. Although site-to-site variability was significant, it was low, with the highest variation for each material being 2 to 5.5 ksi. No significant outliers were identified. There is evidence that the friction stir welding process is path-independent and that a defect-free weld is uniform in tensile strength from beginning to end. There is also evidence that a DOE approach can be used to optimize the weld parameter process window for any tool in order to identify a range of weld parameters where a defect-free weld can be produced. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering.

The importance of race as determinant of social mobility is still an issue that's subject for debate. Particularly among Black Americans, in the midst of the 21st century, the progress of Black American is undeniable yet there still the question of educational inequality, social problems, and income inequality so prevalently associated with inner city Black citizens. Using William Julius Wilson seminal work, the Truly Disadvantaged as a springboard, this thesis examines the implications of the declining significance of race by investigating the social and income differences of Black and White urban males. / Thesis (M.A.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Sociology.

This thesis considers a two-way relay system whereby two nodes exchange information via a relay node. Amplify-and-forward (AF) is applied as a relaying strategy.The channel information is not available at both receivers. The generalized likelihood ratio test (GLRT) and least squares error (LSE) detectors are derived in order to achieve blind unique recovery of the transmitted symbol. It is also proven that full diversity can be achieved. A constellation selection algorithm is designed to optimize the symbol error rate (SER) performance. This thesis also analyzes both theoretical procedures and simulation results of an existing differential detection scheme for two-way relay channels. Monte Carlo simulations demonstrate the performance of the proposed algorithm. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.

Since the nineteenth century, U.S. newspapers have contributing to the promotion of sports, and in the twentieth century, their sports-related news has emphasized the country’s big spectator sports such as baseball, football, and basketball (McChesney, 1989; Fort, 2000). In contrast, throughout the rest of the world, soccer and its FIFA World Cup tournament, which is held every four years, have captured much more attention than it has in the United States (USA Today, 2006). Schlesinger (1978) argued that news does not select itself, but is rather the product of judgments concerning the social relevance of given events and situations based on assumptions concerning their interest and importance. With this in mind, a study was designed in order to learn about how Americans regard soccer and the World Cup and whether their regard for them is undergoing a transition. More specifically, using quantitative content analysis and qualitative inductive thematic analysis, the thesis studied the amount and thematic nature of U.S.A. Today’s news and editorial coverage of the six FIFA World Cup tournaments held from 1990 to 2010. Research indicates that the newspaper published 1,079 articles during these tournaments. The peak of coverage was reached in 1994, when the U.S. hosted the event for the first time. The paper’s reportage and commentary pieces emphasized statistics, history, atmosphere, drama, political, social and international relation affairs. And finally, USA Today characterized the relationship between the FIFA World Cup and the United States as an event that is not for Americans, as the hope of U.S. soccer, as lacking a connection to U.S. television audiences, as a simple game that people from any economic group can enjoy, and as an event with importance not only in the domain of sports, but as one that inspires patriotism. / Thesis (M.A.)--Wichita State University, College of Liberal Arts and Sciences, The Elliott School of Communication.

Students with autism spectrum disorder face many hardships and struggles in life. Video self-modeling appears to be one educational tool that will help to provide the necessary tools for students to be successful, decreases the potential for the student to be victimized by bullies, and increase the quality of life students will have. This study evaluates the use of video self-modeling with a high school freshman who is on the autism spectrum. Video self-modeling was used to decrease the maladaptive behavior of biting himself. The ABA research design allowed for a two week intervention where the student watched a video of himself demonstrating a replacement behavior instead of biting his arm. The study found a statistically significant difference in the incidents of biting in baseline one and baseline two. / Thesis (M.Ed.)--Wichita State University, College of Education, Dept. of Curriculum and Instruction.

This research is aimed to explain the origins and evolution of the philosophical antagonism to male same -sex sexuality under the argument that same-sex relations were contra naturam. It spans from classical Greece through the early middle-ages, and covers Platonism, Aristotelianism, Epicureanism, Greek Stoicism, Roman Judaism, Neoplatonism, and Christianity. A recurrent presence behind all antagonism to male same-sex sexuality was the Socratic ethics of abstention, and notions natural supernatural teleology. Other contributors were negative social connotations of passivity in adult men, and the intrinsic power differences that existed within the male same-sex relationships of antiquity. The argument that same-sex relations go against nature seems to fare worse under more modern understandings of the universe, animal sex-life, and the evidence against intelligent design in evolution of life forms. / Thesis (M.A.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of History.

Adhesively bonded joints are used on numerous applications involving light-weight composite materials. Consequently, the successful modeling and subsequent analysis of bonded joints involving more than one adherend material is crucial for optimization of structural components. An increasing effort to analytically predict the failure strength of adhesively bonded joints has driven the industry’s attention to energy methods such as the virtual crack closure technique. This research attempts to optimize the modeling of such joints in order to acquire accurate analytical predictions with a reasonable computational cost. A detail study of the application of virtual crack closure technique in Abaqus® showed the existence of considerable dependence of results accuracy in mesh densities, element type, and mixed mode criteria used for post processing of the results. The investigation reported herein involves the use of Hysol® EA9394 adhesive to bond components made of two different carbon/epoxy materials, as well as aluminum into single lap shear, double lap shear, T pull-off, and thick lap shear specimens. The results of this research are not intended to provide the analyst with exact parameters for constructing a FEM for a bondline and post processing the results. Rather, this paper provides a procedure for optimizing the finite element model in order to maximize the accuracy-tocomputational time ratio. Additionally, a procedure for correlating the analytical results to test data is provided. It is concluded that adhesively bonded joints can be accurately analyzed using VCCT’s in Abaqus®, provided the finite element models are developed using the technique described herein for obtaining converged analytical solutions. Finally, the correlation of analytical results to test data is not a trivial task that is achieved utilizing the procedure developed during this research. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering.

Friction stir welding has been shown by previous investigators to have many advantages over traditional metal joining practices. Friction stir lap welds and friction stir spot welds have been shown to be stronger than rivets when joining materials of the same thickness. Substructures containing continuous lap welded joints have demonstrated increased load carrying capabilities over their riveted counterparts. In full-scale structures, however, continuous welds are not always an option. Welds may be interrupted by fixturing limitations, tooling restrictions, or stiffening members that cross the weld path. In these situations, a discontinuous lap weld would be necessary. The principal problem with a discontinuous weld is that the tool plunge and exit locations cannot be eliminated with a run-off tab, as in continuous welded structures. These plunge and exit locations are then subjected to operational loads. In fatigue applications, it has been demonstrated that cracks will initiate in the exit hole of a discontinuous weld. The purpose of this study was to investigate techniques to terminate a lap weld without compromising the structure by leaving an unprotected exit hole. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering.

A smart gird improves reliability and efficiency of the power network by actively engaging with customers. Increasing demand for energy, availability of untapped renewable energy, and an aging electric grid infrastructure have motivated researchers to redesign the current electric network . Advanced metering infrastructure (AMI) facilitates implementation of dynamic pricing and predicting load demand in an area through a communication system that also enables customer participation. The home area network (HAN), part of the AMI, is comprised of a smart meter and electric appliances used in the home. A wireless mode of communication is used in the proposed HAN to support the AMI. The exchange of data in a wireless medium is prone to various malicious attacks and interference issues since it is a shared medium. This work investigates security issues in the HAN since it constitutes a major building block for the smart grid. This paper discusses wireless security threats in HAN and possible security solutions. An experimental prototype of a secure wireless HAN framework is designed and implemented. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.

Electrospinning has been widely used in the last decade for research in the field of nanotechnology because of its ability to create sub-micron to nanoscale fibers. In this research work, hydrophilic nanofiber membranes were produced by using the electrospinning process at three different spinneret distances (20 cm, 25 cm, and 30 cm) utilizing a polymeric solution of polyvinyl chloride (PVC) incorporated with polyvinylpyrrolidone (PVP) at different weight proportions ranging from 2% to 5%. Water contact angle values were measured for all of the membranes, and it is observed that membranes produced by maintaining a spinneret distance of 30 cm resulted in a lower contact angle in comparison with other spinneret distances. At the spinneret distance of 30 cm, the 2% and 3% PVP membranes exhibited hydrophobic properties. At 5%, PVP membranes exhibited that of a super hydrophilic nature. The membranes produced at 4% PVP showed the desired hydrophilic nature, which were utilized for the filtration process. Three water samples were selected for the filtration experiments including: lake water, abrasive particles from a water jet cutter, and magnetite nanoparticles. The main concentration of the current research work was to create highly hydrophilic nanofiber membranes and utilize them to filter water at an optimal level of purification (i.e., drinking water). In order to overcome the fouling property of the membrane, coagulation, which enhances the efficiency of the membrane in the removal of colloidal particles, was used as a pre-treatment process. Two coagulants, Tanfloc and Alum, were used during the coagulation process. The removal efficiency of the suspended particles in liquid was measured in terms of turbidity, pH, and total dissolved solids (TDS). It was observed that the coagulation/filtration experiments have shown higher efficiency in the removal of turbidity in comparison with the direct filtration process. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering.