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Modulation And Multiple Access Techniques For Ultra-Wideband Communication Systems, Song Cui
Modulation And Multiple Access Techniques For Ultra-Wideband Communication Systems, Song Cui
ETD Archive
Two new energy detection (ED) Ultra-Wideband (UWB) systems are proposed in this dissertation. The first one is an ED UWB system based on pulse width modulation (PWM). The bit error rate (BER) performance of this ED PWM system is slightly worse than ED pulse position modulation (PPM) system in additive white Gaussian noise (AWGN) channels. However, the BER performance of this ED PWM system surpasses that of a PPM system in multipath channels since a PWM system does not suffer cross-modulation interference (CMI) as a PPM system. In the presence of synchronization errors, the BER performance of a PWM system …
Design Of An Implant For First Metatarsophalangeal Joint Hemiarthroplasty, Atul Kumar
Design Of An Implant For First Metatarsophalangeal Joint Hemiarthroplasty, Atul Kumar
ETD Archive
Osteoarthritis (OA) is the most common form of arthritis and it affects 27 million US adults. OA disease involves all of the tissues of the diarthrodial joint and ultimately, may lead to softening, ulceration, loss of articular cartilage, sclerosis and polished appearance of the subchondral bone, osteophytes, and subchondral cysts. The first metatarsophalangeal joint (MTPJ1) is affected in up to 42 cases of OA. Besides osteoarthritis, other conditions such as rheumatoid arthritis and gout also affect the MTPJ1. Involvement of MTPJ1 with these conditions invariably leads to deformed toe such as hallux valgus and hallux rigidus. Over 150 surgical techniques …
Simplifying Embedded System Development Through Whole-Program Compilers, William Patrick Mccartney
Simplifying Embedded System Development Through Whole-Program Compilers, William Patrick Mccartney
ETD Archive
As embedded systems embrace ever more complicated microcontrollers, they present both new capability and new complexity. To simplify their development, some lessons of computer application development will translate with additional work. This thesis offers one such translation. It shows how whole-program compilers - those that broadly analyze a program's entire source code - can achieve performance gains and remove faults in embedded system applications. In so doing, this yields a novel stackless threading system named UnStacked C. UnStacked C enables cooperative multithreading without the risk of stack overflows in embedded system applications. We also propose a novel preemption system called …
Wireless Signals And Male Fertility, Rand Mouradi
Wireless Signals And Male Fertility, Rand Mouradi
ETD Archive
Rapid advances in wireless technology have increased the number of users of mobile devices. As of 2011, the number of cell phone subscribers have reached 5.3 billion worldwide. Mobile devices have saturated our environment with radio frequency (RF) signals. This situation has created public concern over the effect of such signals on human health. This dissertation focuses on the correlation of RF signals emitted by cell phones with male infertility. A thorough discussion is provided on the effects of RF signals on the development of central nervous system (CNS) neoplasm, the design of these mobile devices, the range of the …
Development Of A Muscle Force Optimization Algorithm To Improve Center Of Pressure During Simulated Walking, Lawrence Dean Noble
Development Of A Muscle Force Optimization Algorithm To Improve Center Of Pressure During Simulated Walking, Lawrence Dean Noble
ETD Archive
The Universal Musculoskeletal Simulator (UMS) was developed at the Cleveland Clinic to facilitate general purpose orthopaedic research that allows investigators to study the in vitro forces applied to bones, tendons and ligaments during simulated exercise of cadaver joint systems. In its original state, the UMS hardware consisted of a rotopod (a specialized hexapod robot), a single rotary tendon actuator and custom LabVIEW software for coordinated control and operation of the system. The focus of this work was to 1) enhance the UMS with a multi-tendon actuator system, 2) develop a muscle force optimization algorithm and evaluate it with a static …
3d Imaging For Planning Of Minimally Invasive Surgical Procedures, Uma Numburi
3d Imaging For Planning Of Minimally Invasive Surgical Procedures, Uma Numburi
ETD Archive
Novel minimally invasive surgeries are used for treating cardiovascular diseases and are performed under 2D fluoroscopic guidance with a C-arm system. 3D multidetector row computed tomography (MDCT) images are routinely used for preprocedural planning and postprocedural follow-up. For preprocedural planning, the ability to integrate the MDCT with fluoroscopic images for intraprocedural guidance is of clinical interest. Registration may be facilitated by rotating the C-arm to acquire 3D C-arm CT images. This dissertation describes the development of optimal scan and contrast parameters for C-arm CT in 6 swine. A 5-s ungated C-arm CT acquisition during rapid ventricular pacing with aortic root …
Partial-Data Interpolation During Arcing Of An X-Ray Tube In A Computed Tomography Scanner, Jaisingh Rajwade
Partial-Data Interpolation During Arcing Of An X-Ray Tube In A Computed Tomography Scanner, Jaisingh Rajwade
ETD Archive
X-ray tubes are used in computed tomography (CT) scanners as the energy source for generation of images. These tubes occasionally tend to arc, an undesired phenomenon where high current surges through the tube. During the time that the x-ray tube recovers to full voltage after an arc, image data is being collected. Normally this data, acquired at less than full voltage, is discarded and interpolation is performed over the arc duration. However, this is not ideal and some residual imperfections in images, called artifacts, still remain. Proposed here is an algorithm that corrects for improper tube voltage, allowing previously discarded …
Free Space Optical Communications With High Intensity Laser Power Beaming, Daniel Edward Raible
Free Space Optical Communications With High Intensity Laser Power Beaming, Daniel Edward Raible
ETD Archive
This research demonstrates the feasibility of utilizing high intensity laser power beaming (HILPB) systems as a conduit for robust free-space optical communications over large distances and in challenging atmospheric conditions. The uniqueness of vertical multi-junction (VMJ) photovoltaic cells used in HILPB systems in their ability to receive and to convert at high efficiency, very high intensity laser light of over 200 W/cm2, presents a unique opportunity for the development of the robust free space optical communication system by modulating information signals onto the transmitted high intensity photonic energy. Experiments were conducted to investigate and validate several optical communications concepts. A …
Dynamic Harmonic Domain Modeling Of Flexible Alternating Current Transmission System Controllers, Bharat Gnvsr Vyakaranam
Dynamic Harmonic Domain Modeling Of Flexible Alternating Current Transmission System Controllers, Bharat Gnvsr Vyakaranam
ETD Archive
Flexible alternating current transmission system (FACTS) and multi-line FACTS controllers play an important role in electrical power transmission systems by improving power quality and increasing power transmission capacity. These controllers are nonlinear and highly complex when compared to mechanical switches. Consequently, during transient conditions, it is very difficult to use conventional time and frequency domain techniques alone to determine the precise dynamic behavior of the harmonics introduced into the system by these controllers. In particular, the time-varying nature of the harmonic components is not captured by these techniques. The contribution of this work to the state of power systems analysis …
Model Identification, Updating, And Validation Of An Active Magnetic Bearing High-Speed Machining Spindle For Precision Machining Operation, Adam C. Wroblewski
Model Identification, Updating, And Validation Of An Active Magnetic Bearing High-Speed Machining Spindle For Precision Machining Operation, Adam C. Wroblewski
ETD Archive
High-Speed Machining (HSM) spindles equipped with Active Magnetic Bearings (AMBs) are envisioned to be capable of autonomous self-identification and performance self-optimization for stable high-speed and high quality machining operation. High-speed machining requires carefully selected parameters for reliable and optimal machining performance. For this reason, the accuracy of the spindle model in terms of physical and dynamic properties is essential to substantiate confidence in its predictive aptitude for subsequent analyses.This dissertation addresses system identification, open-loop model development and updating, and closed-loop model validation. System identification was performed in situ utilizing the existing AMB hardware. A simplified, nominal open-loop rotor model was …
Quantification Of Scenedesmus Dimorphus Growth And Substrate Kinetics For Continuous Photobioreactor Design, Daniela Ribita
Quantification Of Scenedesmus Dimorphus Growth And Substrate Kinetics For Continuous Photobioreactor Design, Daniela Ribita
ETD Archive
Increasing gas prices, limited fossil fuel resources and U.S. dependence on foreign oil make research in alternative fuels a priority. The feasibility of producing fuels from microalgae is economically dependent on improvements in lipid productivity by the algae. The research presented here focuses on the development of a mathematical model to describe the biomass and lipid productivity in a continuously-operated photobioreactor (PBR) system. Five different cell lysing methods were evaluated for the purpose of improving the methods of analysis of lipid synthesis. The two most promising methods were found to be mortar and pestle and organic solvent cell fractionation methods. …
Algea Suspension Dewatering With An Inclined Gravity Settler, Jing Hou
Algea Suspension Dewatering With An Inclined Gravity Settler, Jing Hou
ETD Archive
Biofuel has been studied for several decades as a feasible substitute for petroleum, which may solve the energy crisis. Having a high oil content and growth rate, algae biofuels have received lots of attention recently, and have been considered as one of the most promising technologies to reduce the dependence of fossil fuels. In the process of producing algae biofuel, the dewatering process constitutes a significant part of the cost of the algae biofuel, impeding progress towards large-scale commercial use. An inclined settler utilizes gravity to separate algae cells from the fluid, with little energy consumption. The separation ability of …
One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell
One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell
ETD Archive
The flow of nutrients through any biological tissue is important to maintain homeostasis. If the transport process is understood, medical research teams can better design medications, prosthetic implants, and tissue scaffolds. Additionally, transport rates help physicians to better understand disease states and wound healing, including minor injuries such as breaks and sprains, which will aid in better diagnoses. We developed a novel method that measures the rate of diffusion in vitro, of fluorescein sodium salt. Samples were incubated at 37°C in a 5 CO2 atmosphere for various periods of time. Samples were sliced and analyzed using Image-Pro Plus and MATLAB …
An Assessment Of The Accuracy Of Magnetic Resonance Phase Velocity Mapping In Turbulent Flow Through Orifices, Sahitya Pidaparthi
An Assessment Of The Accuracy Of Magnetic Resonance Phase Velocity Mapping In Turbulent Flow Through Orifices, Sahitya Pidaparthi
ETD Archive
Magnetic resonance phase velocity mapping (MRPVM) is an established clinical technique to measure blood flow. The acquired information can be used to diagnose a variety of cardiovascular disease. One of the main limitations of MRPVM is that it cannot quantify the flow under turbulent flow conditions. Such conditions develop in certain cases such as in heart valve stenosis and arterial stenosis. Specifically, heart valve stenosis is a serious disease in which the valve does not open as much as necessary for blood to pass through. As a result, the heart has to overwork to overcome the increased resistance. If untreated, …
Quality Control Using Inferential Statistics In Weibull Analyses For Components Fabricated From Monolithic Ceramics, Ankurben H. Parikh
Quality Control Using Inferential Statistics In Weibull Analyses For Components Fabricated From Monolithic Ceramics, Ankurben H. Parikh
ETD Archive
No abstract provided.
Probabilistic Structural And Thermal Analysis Of A Gasketed Flange, Atul G. Tanawade
Probabilistic Structural And Thermal Analysis Of A Gasketed Flange, Atul G. Tanawade
ETD Archive
Performance of a flange joint is characterized mainly by its 'strength' and 'sealing capability'. A number of analytical and experimental studies have been conducted to study these characteristics under internal pressure loading. However, with the advent of new technological trends for high temperature and pressure applications, an increased demand for analysis is recognized. The effect of steady-state thermal loading makes the problem more complex as it leads to combined application of internal pressure and temperature. Structural and thermal analysis of a gasketed flange was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties …
Probabilistic Stress Analysis Of Circular Fins Of Different Profiles, Sridhar Madhira Venkata
Probabilistic Stress Analysis Of Circular Fins Of Different Profiles, Sridhar Madhira Venkata
ETD Archive
The temperature distribution and thermal Stresses induced by a temperature difference for steady state heat transfer in silicon carbide (SiC) ceramic tube heat exchanger with circular fins was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for Hoop and Radial stresses due to the structural and thermodynamic random variables. These results are used to identify the most critical design variables in order to optimize the design and make it cost effective. The probabilistic analysis leads to the selection of the …
Modification, Expression, And Purification Of Hyperactive Antifreeze Proteins From Insect Tenebrio Molitor, Sen Bu
ETD Archive
Antifreeze proteins (AFPs), also known as thermal hysteresis proteins, can protect organisms from damage caused by freezing by lowering the freezing point of fluids. AFPs can bind to small ice crystals, inhibit ice growth, and change the morphology of ice crystals. The difference between the freezing temperature and the melting temperature is termed thermal hysteresis (TH). There are different types of AFPs, such as fish AFPs (type I, II, III, and IV) and insect AFPs. These AFPs can also be classified by their thermal hysteresis activity: moderately active AFPs and hyperactive AFPs. Previous research groups successfully constructed AFP (type I, …
Characterization Of Elastin-Like Polypeptides Using Viscometry, Hamdan Noman Alanazi
Characterization Of Elastin-Like Polypeptides Using Viscometry, Hamdan Noman Alanazi
ETD Archive
Elastin-like polypeptides (ELPs) are a class of polypeptide polymers that are gaining interest in various potential applications. These polymers are responsive to the changes in their environment by exhibiting conformational changes and aggregation. Monodisperse elastin-like polypeptides, (GVGVP)40, (GVGVP)40-foldon, and (GVGVP)60-foldon are made in bacterial expression system. An Ubbelohde capillary viscometer was set up to characterize the structural changes of these ELPs in phosphate buffered saline (PBS) solution. For the ELP-foldon, the relative viscosity measurements were utilized to calculate the intrinsic viscosities using Kraemer and Huggins equations. The known molecular weights of the ELPs and the experimentally determined intrinsic viscosities facilitated …
Dietary Supplement Wastewater Treatment By Biological Methods, Xiangting Hou
Dietary Supplement Wastewater Treatment By Biological Methods, Xiangting Hou
ETD Archive
Dietary supplements, pre-mixed meal like Slim Fast, are part of most people's lives. Since dietary supplements have a high order of complex sugars, low-fat milk, and all kinds of nutrients, they bring hazards to the environment if discharged to water bodies without any proper treatment. Therefore, wastewater from dietary supplement gains much more attention at the present time. Dietary supplement wastewater contains amounts of organic compounds which may be bio- friendly and non-toxic. Biological treatment shows its strong advantages in dealing with this kind of wastewater.In this research, four kinds of Live Liquid Micro-organisms (LLMO) were used as the sources …
Electrocoagulation/Flotation Treatment Of Synthetic Surface Water, Sampath Gunukula
Electrocoagulation/Flotation Treatment Of Synthetic Surface Water, Sampath Gunukula
ETD Archive
Rainfall generated surface runoff water could contaminate groundwater through transportation of suspended solids and organic matter in to the aquifer. Surface runoff water composition mainly depends on soil amendment. Surface runoff mainly contains clay, minerals, organic and inorganic matter, total dissolved lead, zinc. ECF technology presents an alternative for the removal of total suspended solids, turbidity, and organic matter from generated surface runoff water. This research presents development of bench scale ECF unit for the treatment of synthetic surface water. Experiments were conducted in a 10 liter Plexiglas unit provided with two aluminum electrodes, one serving as cathode, and other …
Cfd Simulations For The Effect Of Unsteady Wakes On The Boundary Layer Of A Highly Loaded Low Pressure Turbine Airfoil (L1a), Samuel J. Vinci
Cfd Simulations For The Effect Of Unsteady Wakes On The Boundary Layer Of A Highly Loaded Low Pressure Turbine Airfoil (L1a), Samuel J. Vinci
ETD Archive
The study of a very high lift, low-pressure turbine airfoil in the presence of unsteady wakes was performed computationally and compared against experimental results. The experimental data were collected in a low speed wind tunnel under high (4.9 ) and then low (0.6 ) freestream turbulence intensity conditions on a linear cascade with wakes that were produced from moving rods upstream of the cascade. The flow coefficient was kept at 0.7 while the rod to blade spacing was changed from 1 to 1.6 to 2 blade spacings. These cases were conducted for Reynolds number equal to 25,000 and 50,000, based …
A Cfd Model Of Mixing In A Microfludic Device For Space Medicine Technology, Terri Lynn Mckay
A Cfd Model Of Mixing In A Microfludic Device For Space Medicine Technology, Terri Lynn Mckay
ETD Archive
The DNA Medicine Institute (DMI) is currently developing a device to be used for blood analysis to satisfy the unique requirements of space medicine applications. A key component of that device is the micromixer, which will ensure mixing and dilution of reagents utilized for detection assays. As part of the device design process, the micromixer was modeled, and the mixing characteristics were analyzed and compared to experimental data. The experimental data was based on a top-view of the system and, lacking data throughout the fluid domain, could not provide the insight into the mixing process that modeling could readily provide. …
Fabrication And Testing Of A Nonstandard Thin-Film Heat Flux Sensor For Power System Applications, Scott D. Wilson
Fabrication And Testing Of A Nonstandard Thin-Film Heat Flux Sensor For Power System Applications, Scott D. Wilson
ETD Archive
Stirling convertors are being operated by NASA Glenn Research Center for many years to demonstrate a Radioisotope Power System (RPS) capable of providing reliable power for potential multi-year space missions. Techniques used to monitor Stirling convertors for change in performance include measurements of temperature, pressure, energy addition, and power output. It is difficult to measure energy addition to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat energy addition to a Stirling convertor. The one micron thick, …
Evaluation Of Lean Systems In Rail Maintenance Operations, Mert Baykut
Evaluation Of Lean Systems In Rail Maintenance Operations, Mert Baykut
ETD Archive
The recognized strength of lean systems is its broad applicability to every process industry even though they include some complicated and time-intensive processes. However, this conception is based on the tools and philosophy of Lean systems and the nature of the industry. The required craftsmanship and repetitive processes in rail maintenance define the uniqueness of this research The objective of this thesis was to research the opportunities and applicability for lean systems in rail maintenance. During the research a unique system, consisting of Lean systems and systems engineering tools, is realized and tried to integrate instead of a pure Lean …
A Systems Engineering Reference Model For Fuel Cell Power Systems Development, T. L. Blanchard
A Systems Engineering Reference Model For Fuel Cell Power Systems Development, T. L. Blanchard
ETD Archive
This research was done because today the Fuel Cell (FC) Industry is still in its infancy in spite over one-hundred years of development has transpired. Although hundreds of fuel cell developers, globally have been spawned, in the last ten to twenty years, only a very few are left struggling with their New Product Development (NPD). The entrepreneurs of this type of disruptive technology, as a whole, do not have a systems engineering 'roadmap", or template, which could guide FC technology based power system development efforts to address a more environmentally friendly power generation. Hence their probability of achieving successful commercialization …
Fea Analysis Of Novel Design Of Cylindrical Roller Bearing, Prasanna Subbarao Bhamidipati
Fea Analysis Of Novel Design Of Cylindrical Roller Bearing, Prasanna Subbarao Bhamidipati
ETD Archive
This work presents a finite element stress analysis of a novel design of cylindrical roller. The focus of this study is to create a uniform contact-stress distribution along the length of the roller and to recommend a roller bearing design which is easier to fabricate. The new design relies on creating symmetric cylindrical cavities at both ends of a roller. The cavity is concentric with the main body of the roller. The new roller design reduces overall mass of the typical assembly with helps to improve bearing life and its overall performance. The FEA results published herein shows that new …
Vibratory Behavior Of Rolling Element Bearings: A Lagrangian Approach, Phani Krishna Kalapala
Vibratory Behavior Of Rolling Element Bearings: A Lagrangian Approach, Phani Krishna Kalapala
ETD Archive
Vibratory behavior of a rolling element bearing on a horizontal rotor is studied in this work. This Thesis analyzes the dynamics of a typical roller bearing as a result of internal excitations. These internal excitations stem from the geometric deviations of the interacting surfaces from their ideal geometry. Such deviations in turn are the results of either manufacturing limitations or normal wear of the bearing surfaces. Lagrangian approach is implemented to derive the dynamic equations of motion. Matlab is used to solve the equation of motion of governing the vibrations of the system. Parametric studies are conducted to provide results …
Adaptive Sliding Mode Control For Aircraft Engines, Kathryn C. Ebel
Adaptive Sliding Mode Control For Aircraft Engines, Kathryn C. Ebel
ETD Archive
Aircraft engine control has been evolving since its beginning. With advancements in technology more and more control methods are being applied to this area. This thesis presents the design of an adaptive PID sliding mode control (A-SMC) for a turbofan engine. The controller design methodology is presented. Using an aircraft engine simulation environment developed by NASA, called Commercial Modular Aero-Propulsion System Simulation, the developed controller is tested. The results from three simulations are analyzed to investigate the application of this new design scheme. The A-SMC is able to follow the demanded fan speed for short flight simulations. However, some of …
Multivariable Sliding Mode Control Design For Aircraft Engines, Sirirat Sangwian
Multivariable Sliding Mode Control Design For Aircraft Engines, Sirirat Sangwian
ETD Archive
Many control theories are used in controlling aircraft engines. However, the multivariablesliding mode control is not yet established in this application even though ithas a lot of potential in dealing with complex and nonlinear systems such as aircraftengines. Therefore, a guideline in developing multivariable sliding mode control law for an aircraft engine is presented in this thesis. The problem of chattering in thesliding mode control is suppressed by the use of the boundary layer method. The controllogic is tested by implementing NASA's Commercial Modular Aero-PropulsionSystem Simulation 40k (C-MAPSS40k). Simulation results are analyzed and comparedto the results obtained from the baseline …