The pathogenic fungus Batrachochytrium dendrobatidus (Bd) is responsible for mass disruption of amphibian species and causes the disease known as chytridiomycosis which disrupts the amphibian skin resulting in high mortality rates (Pessier et al. 1999). There are limited studies of the internal and immune functions of frogs during Bd exposure exist and studies aimed at understanding the effects of Bd exposure combined with anthropogenic stressors such as nitrate are limited as well. The aim of this study was to test treatment combinations involving nitrate concentration (0, 40 and 80 mg/L) and pre- and post-metamorphic exposure to Batrachochytrium dendrobatidis (Bd). Melanomacrophages (MMPs) were used as biomarkers to understand how treatment combinations impact Xenopus laevis internally. Statistical analyses were used to determine host survivability, mean MMP counts and to correlate frog performance variables with MMP count. To assure Bd treatment was effective PCR was used to detect presence of Bd in specimens. Results indicate negative impacts in groups exposed to 40mg/L nitrate and individuals exposed to Bd after metamorphosis including decreased survivability, indicating that interactions cause high mortality of individuals. Individuals exposed to Bd as tadpoles in 40 mg/L nitrate survived longer, suggesting that early exposure to Bd can result in longer survival time. Frogs with early exposure to Bd resulted in longer survival time. Higher stress was associated with 40 mg/L nitrate and no exposure to Bd after metamorphosis, implicating 40 mg/L nitrate as the cause for higher MMP numbers. High numbers of MMPs in frogs exposed to Bd in the 0 mg/L nitrate groups suggests Bd does stress the frog internally. Surprisingly, groups in the 80 mg/L concentration had fewer MMPs and typically longer lifespans and proportion of individuals surviving, suggesting mitigating effects for frogs exposed to Bd, likely through interaction between Bd and nitrate. / Thesis (M.S.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Biological Sciences

Follicle-stimulating hormone (FSH) is a glycoprotein hormone with two subunits, alpha and beta, and is required for gamete development. FSH is now known to exist as a ratio of two glycoforms that varies during the menstrual cycle and in premenopausal periods in women. A newly identified glycoform, referred to as diglycosylated FSH, is characterized by the presence of two glycans attached to the alpha subunit while none are attached to the beta subunit. Preliminary data suggest that estrogen is responsible for reducing the glycosylation of FSHbeta in reproductive-age women, thus yielding higher concentrations of diglycosylated FSH than is found in older women. This selective reduction of glycosylation of the FSHbeta subunit is suspected to be due to activity of different oligosaccharyltransferase (OST) subunit isoforms. To investigate how the OST subunit isoforms STT3A and STT3B subunit isoforms affect FSH glycosylation, we used a stably transfected GH3 cell line that produces recombinant hFSH, and selectively knocked down each isoform via siRNA transfection, and examined the glycosylation patterns of the hFSH produced. We used a liposomal transfection methodology for siRNA transfection, and chromatographic methods for FSH purification. Following transfection, RNA from transfected cells was isolated and evaluated using reverse transcription and quantitative real-time PCR (RT-qPCR) to measure expression levels of the two isoforms and glycosylation patterns of FSH subunits were examined via Western blot. Ultimately, use of siRNA to selectively knock-down STT3 isoforms did not produce observable variance in FSH subunit glycosylation patterns when compared to controls. Although the RT-qPCR results suggest that isoform knock-down was achieved on some level, the subunit glycoforms captured on the Western blots did not show significant variation in glycoform abundance. / Thesis (M.S.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Biological Sciences

Polymeric materials have a wide variety of applications in many manufacturing industries. However, because of the molecular structures and chemical compositions of polymeric materials, they have considerably low resistances against fire or heat. Although these materials are highly flammable, their flame retardancy can be improved significantly by incorporating the flame retardant nanomaterials. Nanoclay, nanotalc and graphene are some of the examples of the flame retardant nanomaterials. These are highly cost effective and environmentally friendly for these applications. These inclusions have a great potential to improve thermal, electrical, and mechanical properties of the new materials. This study is mainly focused on the effects of nanoparticle additions in the polyvinyl chloride (PVC) in terms of the flame retardancy. Five sets of nanocomposite materials were prepared using the solvent casting method at different weight percentages of the nanomaterials. The flame retardancy values of the resultant nanocomposite samples were determined using the ASTM UL 94 standard tests. The results of the experiment were also supported by the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Surface characterization of the resultant materials was carried out using scanning electron microscopy (SEM), while mechanical properties were determined through a tensile test method. Test results showed that the flame retardancy values of the new nanostructured materials were significantly enhanced in the presence of nanoscale inclusions, which may be useful for various industrial applications. This study may open up new possibilities of using many nanoscale inclusions in various polymers as flame retardant materials for different industrial applications. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering

Thesis (M.A.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of English

The purpose of this research is to determine if there is a correlation between parents' and their third grade students' attitudes towards education and if these attitudes and beliefs affect student motivation and academic achievement. A review of the current literature examines parental involvement in four sections: what parental involvement looks like, the benefits of parental involvement, factors affecting parental involvement and why parental involvement is important for schools. The literature also examines students' attitudes and motivation towards education and discusses types of motivation, causes of motivation and the timing of the student's life at which motivation can be studied. To conduct the research, surveys were given to parents and students in the third grade of an urban elementary school in a large Midwestern city to determine if there was a correlation between parental beliefs and attitudes about involvement and students' attitude and motivation. Student achievement data was gathered from the program used by the school for progress monitoring. Results indicate that parental decisions to be involved are statistically related to invitations from school, role construction, and self-efficacy. Additionally, results indicated that achievement data are positively correlated with role construction and invitations from the child. Findings are discussed and compared to research in which the current study supports and refutes. Limitations to the study, future research, and classroom implications are also discussed. / Thesis (M.A.T.)--Wichita State University, College of Education, Dept. of Curriculum and Instruction

There have been many studies on side impact accidents, crashworthiness of car structures and occupant protection and safety. These studies have focused on either development of better car interiors, belts, airbag safety and seating system for passengers or on more energy absorbing car structures and stronger materials to withstand the accident. The National Highway Traffic Safety Administration (NHTSA) has developed metric method to quality and study the aggressive behavior of Light trucks and Vans (LTV's). One of the methods include driver fatality ratio (DFR) and Accident Safety (AS) by considering statistical data which was obtained from the accidents. The present research work proposes a computational method utilizing nonlinear finite element (FE) modeling of side impact crashes based on Federal Motor Vehicle Safety Standard (FMVSS) 214 and the United States New Car Assessment Program (USNCAP) conditions of several bullet and target vehicles. A computational finite element crash simulation methodology is initialized in this study include twelve cases, in which there are three target cars struck from side by four different bullet cars. The target cars include the Dodge Neon, Geo Metro and Toyota Yaris; and the bullet cars include the Dodge Caravan, Ford Econoline, Ford Explorer and Chevy S-10. The intrusions of the bullet and target cars are captured at specific locations. A scheme is then utilized to estimate the DFR based on the ratio of the bullet and target car intrusions, as well as the ratio of the accelerations at the driver seats corresponding to the two cars. The estimated DFR has been compared to the statistical DFR based on the accident data, and shown to provide reasonable correlation. The target vehicles in this study have been changed from the older models to a new model in order to observe any influence on the predicted DFR. The methodology presented here can be used in the design stage of new cars in order to improve the occupant protection and survivability of the passengers in the designed vehicles. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering

Kevlar, an aramid fiber, is one of the most widely used materials for various industrial applications, such as aerospace, automotive, sports, wind energy, biomedical, optics, as well as defense due to its extraordinary mechanical and thermal (fire retardancy) properties and lightweight. In the present study, graphene nanoflakes and nanoclays dispersed in epoxy resins at different weight percentages (0 to 10 wt.%) were incorporated with dry Kevlar fibers through wet-layup process, and then cured under vacuum and high temperature to make Kevlar/epoxy hybrid composites. The prepared composite panels of 16-ply were impact tested using a low-velocity impactor, and C-Scanned before and after the impact tests. During the impact tests, the impact force vs. displacement, impact force vs. time and impact energy values of the composite panels were analyzed and compared. The c-scans of the damaged composite panels were analyzed for damage area and depth. The damaged test panels were exposed to UV light and moisture for 8 days, with an interval of 4 days. The water contact angles around the damaged area were measured for each damaged composite panel. The test results, impact analysis and damage analysis showed that the nanoscale inclusions in the Kevlar/epoxy composites had a major impact in dissipating the kinetic energy into heat, other forms of energy, and elastic and plastic deformation, and thus saving the composite panels from the major damages. This comparative research study illustrated that the variation in nanomaterials in the epoxy of a composite makes a significant difference in the impact response of the laminate. This result may be useful for the further improvement of the Kevlar-based products in various industries. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering

The purpose of this thesis is to investigate the role of smoothness, specifically the smoothness of the boundary ∂Ω, in the behavior of the variational solution f on a domain Ω to the Dirichlet problem for the Minimal Surface Equation at a point O ∈ ∂Ω when the (generalized) curvature of ∂Ω has a negative upper bound in a neighborhood of O. We give examples which show that the assumption of boundary-regularity which Simon made in [12] or at least some weaker boundary-regularity assumption which excludes nonconvex corners in the boundary of the domain is necessary in order to guarantee that the variational solution of the Dirichlet problem for the Minimal Surface Equation is continuous in the closure of the domain for every Lipschitz-continuous boundary-data function ϕ : ∂Ω → R. This is independent of whether or not f equals ϕ on ∂Ω. Furthermore, these examples give credence to the Concus-Finn Conjecture, which still awaits to be proven in the case that the contact-angle is 0 or π at nonconvex corners. / Thesis (M.S.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Mathematics, Statistics, and Physics

Dynamic mechanical analysis (DMA) is the most preferred thermal analysis technique for determining the glass transition temperature (Tg) of polymer matrix composites because it is more sensitive to Tg measurements than other thermal analysis techniques. An interlaboratory study was developed and conducted by the American Society for Testing and Materials (ASTM) for its D7028-07 test standard (Tg by DMA). The results of the study indicated that reproducibility was poor between DMA instruments and laboratories. A reproducibility standard deviation of 15.09 degree F and 14.72 degree F for dry Tg and wet Tg measurements, respectively, was found. Poor reproducibility of Tg measurements creates uncertainty in cases where Tg measurements are utilized. Service temperature and process control determinations may be difficult to establish if reproducibility of Tg measurements remains poor. The goal of this research was to improve laboratory-to-laboratory and instrument-to-instrument reproducibility. To accomplish this, several potential influencers of Tg measurements, such as, thermocouple positioning, dimensional variation of specimens, and temperature calibration configurations and methods were evaluated. These evaluations were the framework to the development of thermocouple guidelines and temperature calibration procedures to aid test operators in areas where the test and calibration standards are not specific. To assess whether this goal was achieved, a follow-on interlaboratory study was conducted. A reproducibility standard deviation of 7.86 degree F and 7.30 degree F for dry Tg and wet Tg measurements, respectively, was determined. When compared with the interlaboratory study conducted by ASTM, the follow-on interlaboratory study indicated a 50% improvement in the reproducibility of Tg measurements was achieved with the implementation of the developed thermocouple guidelines and temperature calibration procedures. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering

Safety in air transport has always been of paramount importance. The very nature of aircraft navigating through the atmosphere brings with it associated risks and dangers. Some of these dangers are manifested in the form of adverse atmospheric disturbances. Two common examples of these atmospheric disturbances are the microburst and the wake vortex. This thesis explores the response and recovery performance of a General Aviation-based Model Reference Adaptive Control (MRAC) control system when subjected to these atmospheric disturbances. For the microburst condition, an existing 3DOF MRAC controller developed through prior research is integrated with nonlinear aerodynamics and an envelope protection scheme that augments the flight envelope of a Beechcraft Bonanza/CJ-144 as it encounters conditions pursuant to a microburst condition. Through simulation, the envelope protection scheme is shown to improve the chances of safe recovery in the event of a microburst encounter, by limiting the amount of total kinetic energy loss as the aircraft enters the microburst. For the wake vortex condition, an existing 6DOF MRAC controller is used as a baseline, to which a custom-developed 3D wake vortex model is added. Nonlinear components are incorporated into the existing linear aerodynamics, along with an envelope protection scheme. Pilot-in-the-loop simulated flight testing is conducted to evaluate recovery performance under three control modes: controller only, controller with pilot, and pilot only without controller. The control modes with the controller active are shown to yield much better recovery performance in the event of a wake vortex encounter. Additional efforts include the complete development of a MATLAB/Simulink-based 6DOF Aircraft Motion Visualizer and an X-Plane-based external simulation interface, both used as tools to aid in analysis of results and simulated flight testing. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering