A statistically based analytical method was developed to improve the reliability of fatigue failure predictions for metallic components of various geometric configurations subjected to constant amplitude fatigue loads. The method required the determination of the distribution of equivalent initial flaw sizes. The equivalent initial flaw size associated with an actual crack is influenced by the geometric configuration of the body, the applied loading conditions and the crack growth model employed. In this study four factors were identified including two types of crack configurations and their influence on the equivalent initial flaw size distribution was investigated. Also the influence of the four factors on the equivalent initial flaw size distribution was examined. These are the stress concentration factor, tg K, the uncracked ligament length, n w, the maximum stress, max S and mean stress, mean S, of the applied constant amplitude fatigue loading. Two types of initial crack configurations were assumed; corner and surface flaw. Five specimen types were investigated; smooth unnotched, open-hole, Kt = 3, 4 t K = and 5 t K = specimens all of which have different stress concentration factors. Two statistical models were fitted and investigated. One model assumed that the initial crack started as a corner crack, transitioned into a through crack, and then propagated till final fracture. The other model assumed that the initial crack started as a surface crack, transitioned into a through crack, and then propagated till final fracture. For each crack configuration, a statistical model was fitted between the mean and the standard deviation of the distributions of the equivalent initial flaw sizes and the stress concentration factor, the uncracked ligament length, the maximum stress, and the mean stress of the fatigue loading. Multiple regression techniques were used to fit these models. Using the statistical models together with Monte Carlo simulation, a distribution of estimated fatigue lives were generated using the FASTRAN-II crack growth code for the Kt = 3 and 4 t K = specimen types, at various stress levels. Hypothesis testing was used to compare the estimated fatigue lives of the specimen with the measured fatigue lives obtained from testing at a level of significance of 0.05. An acceptance criterion was established to determine if the predicted fatigue lives compared well with experimentally obtained fatigue lives. As a conclusion, the methodology provided adequate approximation of fatigue life for some of the fatigue loading cases of the 4 t K = specimens and for one of the fatigue loading cases of the 3 t K = specimens. The initial crack configuration type did not have any significant effect on the proposed methodology. / Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering / "December 2007."

Business competition requires organizations to increase their products’ quality and reduce cost at the same time. Statistical process control (SPC) techniques are important tools for monitoring process performance over time to detect special causes. Automatic process control (APC) systems, on the other hand, are utilized to regulate performance relative to a specified target. The literature indicates that combining APC and SPC systems result in integrated SPC (ISPC) systems offering an effective approach to process improvement. The objective of this research was twofold. The first objective was aimed at identifying the various process factors likely to affect the long-term performance of ISPC systems. The process considered was one of discrete parts manufacturing characterized by the integrated moving average model IMA (1, 1). A simulation model was developed to represent system performance in terms of the mean squared error (MSE) of the resulting output and the average run length (ARL) of the SPC chart utilized. Simulated results were analyzed to identify influential factors likely to affect the system performance. The second objective targeted the development of criteria for the economic performance of ISPC systems. Two mathematical cost models were developed utilizing Taguchi’s quadratic loss function and accounted for key characteristics of the process and system design factors. These two models were used to derive criteria for the economic selection of the SPC chart design parameters. It is hoped that the proposed criteria will help practitioners select appropriate charting alternatives to minimize the total cost of operation. / Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Industrial and Manufacturing Engineering / "December 2007."

Nitrile Hydratase (NHase) is a bacterial enzyme which catalyzes the hydrolysis of organic nitriles to their corresponding amides. The active site of NHase contains Fe (III) or Co(III) ions in an unusual coordination sphere containing 2 amide N atoms and three S donors. The research described herein is an attempt to model this active site using two different model systems: one that generates metal-coordinated imines, and one that generates metal-coordinated amides. Using 2,2’-dithiodibenzaldehyde and derivatives of 2,2’-dithiodisalicylic acid as reactants, several new and interesting metal coordinated imine and metal coordinated amide complexes have been synthesized. The synthesis and crystallization of several new organic and ligand species is discussed as well. The synthesis of a Co complex that resembles the active site of NHase is reported herein, along with several other new organometallic species. Also, two projects using computational chemistry are reported: one modeling trispyrazolylborate (Tp) complexes of iron and copper, and one modeling iron, manganese, and copper complexes of pentadentate imine/phenolate ligands. Complexes of Tp ligands with relatively bulky substituents in the 3-position are subject to isomerization through a borotropic shift. Computational chemistry has shed light on the energetics behind the borotropic shift. Calculations on the CO stretching frequency of several different TpCu(I)CO complexes have been carried out in an effort to match experimental data and generate predictive values for several other species not yet synthesized. This stretching frequency can generally be directly related to the electron withdrawing/donating character of the Tp ligand attached to the metal center. Pentdentate imine/phenolate ligands can coordinate to transition metals in a number of isomers. Computational chemistry has been used to shed light on the structural preferences of the iron, manganese, and copper species. These calculations were able to match the experimental data for crystallographically characterized species, and the metal complexes were shown to have specific structural preferences depending on the identity of the metal used. / Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry / "December 2007."

Manufacturing facility layout is determined by minimizing the Material Handling (MH) cost associated with the manufacturing of products. A manufacturing facility operates in a dynamic environment where the production rates and product mix are continuously changing. In addition, the introduction of new products/machines and removal of existing products/machines render the existing layout completely unreliable to yield improved productivity. Hence, it is often necessary to analyze the current layout and redesign the layout in accordance with the constantly changes in demand. Existing methods for the analysis of redesign uses multiple, static, and tabular from-to charts. These charts assume and exhibit the timely demand as a discrete invariable quantity. A new tool, “Dynamic From Between Chart (DFBC)” that allows easier visualization of the changes in product rates and mix is introduced and developed in this research. DFBC models the production rate changes using a continuous function. The development process of the new tool, the formulation of the cost function and its application to the solution of Dynamic Facility Layout Problems (DFLP) for multiple time periods is presented with the use of a case study. The solution methodology uses a tradeoff analysis between increased MH cost and the rearrangement cost for the transition from existing layout to a new layout. To further authenticate and strengthen the developed methodology, real world case studies are considered and evaluated. Importance of any department flow over the other departments (crossover) occurs only if there is variation in the flow volumes between relative departments. In previous research, the redesign is carried out at the end of specific time period in a given time horizon. In most instances, the need for redesign or change in flow occurs somewhere during the period and identifying such crossover points will assist to yield better savings. In addition, the exact time at which the layout should be modified can be determined. For large size problems, the number of crossover points sited in DFBC will be large and evaluating each of these points to identify the point of change in layout will be tedious and time consuming. Thus, along with the methodology to identify the crossover points a concept of Upper bound and Lower bound (UB–LB) to discover the set of redesign points which may warrant a change in layout has been developed. Further analysis is necessary to detect the point(s) that initiate the change. Limiting the solution space facilitates the evaluation of large size problems by reducing and simplifying the computation. Multiple case studies are considered and evaluated to indicate the applicability of the concept. It is also evident in current manufacturing paradigms that the introduction of new products/machines and removal of existing products/machines in-between the time horizon induces huge flow variations between departments. Previous research on DFLP does not deal with models which adopt such scenarios. In this research the application of DFBC to analyze the impact of introduction of new products/machines and removal of existing products/machines in between the time horizon is considered. The ability of the DFBC to address such scenarios is evaluated using a case study. Finally, the possible extensions of this research are listed along with the conclusions on the proposed approach. / Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Industrial and Manufacturing Engineering / "December 2007."

Typical bird shapes used in numerical bird strike analyses include a number of primitive geometries, such as the right circular cylinder, hemi-spherical cylinder, sphere and ellipsoid. There are also some simplifying assumptions made regarding the modeling of the bird material. Yet, the open literature on the subject includes no comparative study to systematically investigate the effect of the projectile shape or bird model material on the accuracy of impact loads analyses. This research filled this gap by showing how various primitive projectile shapes, a more complex bird-like shape, and several homogeneous and heterogeneous material models affect the calculated impact loads. Comparisons to actual bird impact test data were provided, wherever possible, to validate these results. The bird strike event is characterized by three important phases: shock compression, shock decay, and the establishment of a steady state condition. In addition to reproducing the entire pressure-time history, a rational numerical simulation of bird strike analysis should accurately replicate both the Hugoniot shock pressure and the steady state stagnation pressure. Since the bird is generally represented as a soft body material to model its hydrodynamic behavior, an accurate representation of the bird’s equation of state is critical to predicting correct impact loads. In this research, the study of various homogeneous and heterogeneous bird materials depended on the use of accurate equation of state models for each material. Initially, two equations of state – representing the shock compression phase and the steady state compression phase – were studied. This approach follows that of previous research; but, the full 3-D numerical simulation requires a single equation of state to represent the entire impact event. Therefore, an equation of state that combined these two models was derived. Its validity was confirmed by comparing the analytical results from this equation of state with the results from experimental tests. In addition, the effect of porosity in combination with this equation of state was investigated. Additionally, the effects of oblique impact and target flexibility on the bird impact loads were investigated using the traditional, homogeneous bird torso model. Both of these factors acted to lower the Hugoniot shock pressures. The exploration of multi-material bird models in this work began with the study of two different materials, randomly distributed throughout a simple, hemispherical-ended cylindrical bird model. This was followed by introducing high and low density regions in this bird torso model to include the effects of bones and lungs, respectively. Finally, this work studied a more complete, geometrically accurate bird model that included physical shapes and material properties to represent the head, neck, bone structure, lungs, and wings, in addition to the torso. The effect of these multi-material bird models on both the Hugoniot pressure and the steady state pressure is presented in this work. / Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering / "December 2007."

As Internet users become more sophisticated, so do their requirements for the websites they utilize. Two major factions in the field of website design have argued over the importance of site usability vs. site appeal. Previous research examined site usability as a main component of user satisfaction on the Internet. Current research is beginning to examine the aesthetic appeal of websites and the impact on user satisfaction. This research attempted to address the following questions: 1. Do individual differences affect user ratings of site appeal? 2. Do usability and appeal manipulations to websites affect satisfaction, perceived usability and interest in the site? 3. Does the type of task a user is completing on the Internet impact their awareness of the site’s appeal and usability? In a two part study, users evaluated the aesthetic appeal of site homepages to determine if individual differences impact site first impressions. In a follow up study, users completed different types of tasks on sites with varying levels of appeal and usability. Results indicate that there individual differences do not appear to influence on site appeal ratings. When users are asked to evaluate sites with varying degrees of appeal and usability, their first impressions are most influenced by the appeal of the site. Those viewing the sites with low appeal were not positively influenced by the site’s usability, even when the site was easy to use. Participants viewing sites with high appeal were aware of changes to usability and their site ratings decreased when the site had poor usability. Finally, task type appeared to impact user judgments on the site. Participants actively searching for information were more aware of usability issues than participants instructed to explore the site with no specific task requirements. / Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Psychology / "December 2007."

The research presented in this dissertation deals with the electrochemical, anion binding and photochemical studies of various oxoporphyrinogen systems. The first chapter provides a brief introduction to the material discussed in subsequent chapters. The second chapter discusses the electrochemical, spectroelectrochemical, computational (ab inito), and structural characterization of an extended family of N-substituted oxoporphyrinogens. The effect of increasing N-substitution on the electrochemical and spectroelectrochemical properties was systematically investigated. Chapter three focuses on the anion binding properties of the oxoporphyrinogens. The compounds were studied by optical and electrochemical methods to determine the response of the oxoporphyrinogens in the presence of anions. Chapter four deals with the electron/energy transfer processes occurring in supramolecular systems composed of oxoporphyrinogens and zinc porphyrin and the effect of functionalized fullerene when selfassembled to the systems. The photochemical measurements revealed energy transfer in nonpolar solvents, while in polar solvents electron transfer was possible and upon coordination to fullerene there was a higher degree of charge stabilization. The compounds discussed in this thesis were studied by optical absorbance and emission, electrochemical, and time-resolved photochemical methods. These compounds were mainly characterized by 1H NMR, UV-vis absorbance, and ESI-mass. Binding constants for the supramolecular complexes were calculated using UV-vis spectroscopic methods. Density functional theory (DFT) calculations were performed to gain insight concerning structural and orientation of the donor-acceptor groups in these supramolecular complexes. Electrochemical studies were performed to obtain free energy changes for charge separation and charge recombination and to find trends in the redox potentials with increasing N-substitution in the oxoporphyrinogens. Spectroelectrochemical measurements were carried out to find the peak positions of anion and cation radicals for the oxoporphyrinogens with the various substitutions. Steady state and time resolved fluorescence emission studies and transient absorption studies were employed to obtain charge separation and charge recombination rates and the lifetimes of the photo-induced electron transfer events. / Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry / "December 2007."

This mixed methods research examined whether graduates from the teacher preparation program at a small college in the mid-west United States were perceived to be prepared to meet the needs of all learners in their classrooms. Study participants were 22 teacher education graduates from 2001-02, 2002-03, and 2003-04, and 11 of their first year supervisors. Data was gathered by way of an on-line survey, from e-mail and telephone interviews, and from teacher education program documents. Data was analyzed through the lens of the four components of a culturally responsive pedagogy; caring, communication, curriculum, and instruction. Teachers from the 2001-02 cohort who had received no training in a culturally responsive pedagogy seemed to be less well prepared to meet the needs of all learners than were teachers from the other two cohorts. Teachers from the 2003-04 cohort whose course requirements included a course in cultural diversity with emphasis on a culturally responsive pedagogy appeared to be better prepared but were also more critical of their own endeavors. Furthermore, perceptions from outside observers indicated that between 2001 when the teacher preparation program curriculum did not include culturally responsive pedagogy and 2004 after the program incorporated it into coursework, the preparation of teachers to meet the diverse needs of all learners had improved. This study, supported by other research, demonstrated that the inclusion of training in the use of a culturally responsive pedagogy in a teacher preparation program can be effective in readying teachers to meet the diverse needs of all learners. / Thesis (Ed.D.)--Wichita State University, College of Education, Dept. of Educational Leadership / "December 2007."

The purpose of my study was to discover the successful teaching practices of teachers in a Standard of Excellence elementary school. My study also identified the necessary ecological conditions for the teachers to sustain and extend their successful teaching practices. Due to limited research on the study of successful teaching practices of teachers as it relates to student achievement, this study sought to describe the successful teaching practices of teachers in a SOE elementary school, and it sought to understand the conditions to help sustain and extend their successful teaching practices. The design of this study was a qualitative case study conducted through an appreciative inquiry theoretical perspective and capacity building theory. An appreciative inquiry theoretical perspective is an inquiry process that seeks to affirm and build on strengths and past successes of the participants to discover what gives life to their organization or its positive core. Capacity building theory encourages the conditions and opportunities for shared learning and collaboration. Participants were asked to volunteer to participate in various data collection methods: semi-structured paired interviews, focus groups, and participant created documents. Data were unitized, sorted, and coded through an open and axial coding process (which is a process of breaking down the data and then synthesizing it in a meaningful way) (Strauss & Corbin, 1990), using text analysis software (Ryan & Bernard, 2000) so that the participants’ perspectives were synthesized in a manner that allowed the research questions to be answered (Huberman, 1990). Content analysis simultaneously coded the content and constructs relevant categories (Merriam, 2001). CATPAC software was used as an initial foundation of reading text for the interrelationships between words allowing themes to emerge (Woelfel, 1990). Data was compared by categories, themes, or dimensions of information (Creswell, 1998). Participants were guided through two phases of the AI 4-D Cycle of discovery and dream. Detailed field notes were taken and information was collected from multiple perspectives. Five salient findings emerged from the data analysis: (1) Lincoln Elementary School is a cohesive group of educators who seek to help students reach their potential; (2) Lincoln Elementary School educators collaborate to strengthen and enhance instructional practices; (3) Lincoln Elementary School educators value and care about all school stakeholders; (4) Lincoln Elementary School educators created an inclusive community bound by strong interpersonal relationships; (5) Lincoln Elementary School educators want to create a learning environment that is student centered and family oriented where teachers use progressive practices in teaching students. The findings from my research suggested that the appreciative inquiry process has the potential to change teachers’ pedagogical practices and the conditions for the practices to sustain. Using an appreciative inquiry process in this research study empowered participants and sparked a new vision of optimism, hope, and a passion for teaching. All the findings from this study have the potential to transform how educators meet the demands of school accountability and look to sustain high performance by describing the successful teaching practices and the ecological conditions needed to sustain and extend these practices. / Thesis (Ph.D.)-- Wichita State University, College of Education, Dept. of Educational Leadership

A number of laws have been passed in recent decades governing the wiretapping and interception of conversations on the PSTN and recently the internet. The Communications Assistance for Law Enforcement Act (CALEA) passed in 1994 requires that digitally switched telephone networks be designed and built with wiretap capabilities and that service providers assist Law Enforcement Agencies (LEA) in obtaining the desired surveillance. The FCC has ruled that the CALEA also applies to Voice over IP (VoIP) conversations. This has generated considerable contention amongst the internet community regarding the extent to which wiretapping should be embedded into the applicable internet protocols. A number of industry opinions have been expressed that providing wiretap capability will reduce the security of the internet and compromise the basic internet design paradigm. That paradigm expresses the view of placing the complexity in the applications implemented by end users and simplicity in the routing of information between them. The IETF has provided general guidelines regarding architecture for the interception and availability of the information to the LEAs but has declined to produce a full fledged standard. Internet component manufacturers have driven the effort to meet the requirements of CALEA. However in an effort to meet the understood surveillance requirements none of the existing architectures adequately address the issue of end user encryption both in the signaling and content messages. Law enforcement agencies must rely on access to available decryption tools which may delay the timely response to threatening situations in the current war on terror. A key management system which allays the concerns with internet security and complexity is addressed in this investigation. / Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Electrical and Computer Engineering