Engineering Commons^™

Design, Fabrication, Modeling And Characterization Of Electrostatically-Actuated Silicon Membranes, Brian C. Stahl

Master's Theses

This thesis covers the design, fabrication, modeling and characterization of electrostatically actuated silicon membranes, with applications to microelectromechanical systems (MEMS). A microfabrication process was designed to realize thin membranes etched into a silicon wafer using a wet anisotropic etching process. These flexible membranes were bonded to a rigid counterelectrode using a photo-patterned gap layer. The membranes were actuated electrostatically by applying a voltage bias across the electrode gap formed by the membrane and the counterelectrode, causing the membrane to deflect towards the counterelectrode. This deflection was characterized for a range of actuating voltages and these results were compared to the …

Bioflocculation For Control Of Wastewater Pond Microalgae, Daniel Thomas Frost

Master's Theses

Investigates several hypotheses regarding the use of bioflocculation as a harvesting method for wastewater pond microalgae. Research performed on pilot-scale high rate ponds (HRPs) on the California Central Coast.

High Speed Wavelength Tuning Of Sgdbr Lasers For Optical Coherence Tomography Applications, Benjamin Maher

Master's Theses

The application of Sample Grated Distributed Bragg Reflector (SGDBR) wavelength tunable lasers for swept-wavelength Optical Coherence Tomography (OCT) is explored. OCT is a method of measuring reflectivity versus distance into samples under test with a focused infrared light source. Swept wavelength OCT requires a laser light source that is capable of sweeping its wavelength quickly over the entire wavelength range of the tunable laser. Fast sweeping of the laser's wavelength enables real-time imaging of a wide surface area of the surface under test. This thesis will show that SGDBR lasers can be designed to meet the fast wavelength ramp speeds …

Application Of Parent-Child Uav Tasking For Wildfire Detection And Response, Stephen T. Kubik

Master's Theses

In recent years, unmanned aerial vehicles (UAVs) have become a dominant force in the aerospace industry. Recent technological developments have moved these aircraft from remote operation roles to more active response missions. Of particular interest is the possibility of applying UAVs toward solving complex problems in long-endurance missions. Under that belief, the feasibility of utilizing UAVs for wildfire detection and response was investigated in a partnership that included NASA’s Aeronautics Research Mission Directorate and Science Mission Directorate, and the United States Forest Service. Under NASA’s Intelligent Mission Management (IMM) project, research was conducted to develop a mission architecture that would …

Analysis And Design Of Interleaving Multiphase Dc-To-Dc Converter With Input Lc Filter, Kevin Thomas Delrosso

Master's Theses

The future of microprocessors is unknown. Over the past 40 years, their historical trend has been for adopting smaller and more powerful designs that drive the world that we live in today. The state of the microprocessor business today faces a crossroad, wishing to continue on the historical trend of doubling the number of transistors on a chip every 18 months (Moore’s Law) but also facing the realistic task of needing to power these sophisticated devices. With the low voltages and high currents that are required for these microprocessors to operate, it poses a difficult task for the future designers …

Control And Sensor Development On A Four-Wheel Pyramidal Reaction Wheel Platform, Jeffery Jay Logan

Master's Theses

The Pyramidal Reaction Wheel Platform, or PRWP, is used to simulate three-axis controls in a torque free space-like environment. The primary purpose of the system will be to evaluate the effects of conjoining sensors to maximize pointing accuracy. Furthermore, the system will incorporate a star tracker in conjunction with a Simulated Star Field (SSF) to better estimate the PRWP orientation. For the sake of this document, however, the goal is to implement a gyroscope, wheel rate sensors, and a make-shift accelerometer—to the PRWP—and integrate a controls algorithm such that three-axis controls are achieved for the PRWP. Three sensors were either …

Design And Optimization Of A Blood Vessel Mimic Bioreactor System For The Evaluation Of Intravascular Devices In Simple And Complex Vessel Geometries, Sara M. Leifer

Master's Theses

Coronary artery disease affects millions of people and the ability to detect and treat the disease is advancing at a rapid rate. As a result, the development of intravascular technologies is the focus of many medical device manufacturers. Specifically, coronary stent implantation is being performed in an increasing number of patients and a number of new stent designs have been introduced to the market, resulting in the need for improved preclinical testing methods. An in vitro tissue engineered “blood vessel mimic” (BVM) system has previously been established and its feasibility for the initial testing of newly emerging intravascular technology has …

Analysis And Design Of Multiphase Multi-Interleave Dc-Dc Converter With Input-Output Bypass Capacitor, Furqan Mubashir Saleemi

Master's Theses

The power requirements for the microprocessor have been increasing as per Moore's Law. According to International Technology Roadmap (ITRS), the Voltage Regulator Module (VRM) for the microprocessor will be 200 W(with 1V, 200A output) in 2010. With the VRMs topology of synchronous buck, serious technical challenges such as small duty cycle, high switching frequencies, and higher current demands, contribute to decreased power density and increased cost. This thesis proposes a Multiphase Multi-Interleave Buck topology to solve the technical challenges of powering future microprocessors. The critical design parameter values are selected using the theoretical design equations and calculations. The design is …

Predicting The Seismic Behavior Of The Dywidag Ductile Connector (Ddc) Precast Concrete System, Elizabeth Mary Kenyon

Master's Theses

Structural engineering is heavily dependent on the use of computers. When creating a building model using structural analysis software, it is required that the designer have an understanding of the system behavior and the modeling program capabilities.

Some engineers in the Southern California region are taking steps towards incorporating the Dywidag ductile connector (DDC) and super hybrid systems into building practice due to the advantages found in these systems’ construction methods and seismic performance.

As the DDC and super hybrid systems reach industry, the design engineer will need to model these systems using structural analysis programs. This report describes two …

Development Of A Cell Depositing System Using Inkjet Technology, Jason Robert Ozaeta

Master's Theses

In the past decade, advances in tissue engineering have allowed researchers to fabricate simple tissues. However, the process of creating these native tissues is a time consuming and inefficient process. A scaffold must first be fabricated then exposed to a sea of cells in the hopes of seeding. Furthermore, even though cells may have attached, more time must be spent in order to allow the cells to migrate to their ideal locations. To deal with this problem, researchers have investigated whether rapid prototyping principals could be adapted to facilitate the cell seeding process by placing cells in their respective locations …

Theory, Simulation, Fabrication And Testing Of Double Negative And Epsilon Near Zero Metamaterials For Microwave Applications, Neil Patel

Master's Theses

Natural structures exhibiting simultaneous negative bulk permittivity and permeability have not yet been discovered. However, research interest over the past five years has grown with the proposition that artificial structures exhibiting these properties are realizable using specially-designed metallic inclusions embedded in host dielectric bodies. A periodic structure of metallic inclusions much smaller than the guided wavelength and embedded in a host dielectric medium is known in the physics and microwave communities as a "metamaterial". Such frequency-dependent effectively homogeneous materials may be designed to exhibit negative permeability and permittivity at certain frequencies. As predicted by electromagnetic theory, such negative index or …

Cfd As Applied To The Design Of Short Takeoff And Landing Vehicles Using Circulation Control, Tyler M. Ball

Master's Theses

The ability to predict the distance required for an aircraft to takeoff is an essential component of aircraft design. It involves aspects related to each of the major aircraft systems: aerodynamics, propulsion, configuration, structures, and stability and control. For an aircraft designed for short takeoffs and landings (STOL), designing the aircraft to provide a short takeoff distance, or more precisely the balanced field length (BFL), often leads to the use of a powered lift technique such as circulation control (CC). Although CC has been around for many years, it has never been used on a production aircraft. This is in …

Two-Dimensional Computer-Generated Ornamentation Using A User-Driven Global Planning Strategy, Dustin Robert Anderson

Master's Theses

Hand drawn ornamentation, such as floral or geometric patterns, is a tedious and time consuming task that requires much skill and training in ornamental design principles and aesthetics. Ornamental drawings both historically and presently play critical roles in all things from art to architecture; however, little work has been done in exploring their algorithmic and interactive generation. The field of computer graphics offers many algorithmic possibilities for assisting an artist in creating two-dimensional ornamental art. When computers handle the repetition and overall structure of ornament, considerable savings in time and money can result. Today, the few existing computer algorithms used …

Lipid Productivity Of Algae Grown On Dairy Wastewater As A Possible Feedstock For Biodiesel, Ian C. Woertz

Master's Theses

The objective of this thesis is to develop a biological wastewater treatment system that utilizes algal growth to simultaneously create renewable energy in the form of biodiesel and digester biogas, remove polluting nutrients, and abate greenhouse gases. Research under the Department of Energy Aquatic Species Program during 1978-1996 concluded that cultivating algae for biofuels was cost prohibitive at that time and that an integrated approach should be studied that combined wastewater treatment with algal biofuel production. Nutrient removal, in particular nitrogen and phosphorus, from wastewater is a growing regulatory need and the use of algae cultivation could create a unique …