Engineering Commons^™

Adaptive Control Techniques For Transition-To-Hover Flight Of Fixed-Wing Uavs, Brian Decimo Marchini

Master's Theses

Fixed-wing unmanned aerial vehicles (UAVs) with the ability to hover combine the speed and endurance of traditional fixed-wing fight with the stable hovering and vertical takeoff and landing (VTOL) capabilities of helicopters and quadrotors. This combination of abilities can provide strategic advantages for UAV operators, especially when operating in urban environments where the airspace may be crowded with obstacles. Traditionally, fixed-wing UAVs with hovering capabilities had to be custom designed for specific payloads and missions, often requiring custom autopilots and unconventional airframe configurations. With recent government spending cuts, UAV operators like the military and law enforcement agencies have been urging …

St. Jude Medical: Pulmonary Edema Monitoring In Pacemakers And Icds, David Wei-Péng Chang

Master's Theses

Pulmonary edema occurs when fluid leaks from the pulmonary capillary network into the lung interstitium and alveoli. When the heart is not able to pump blood to the body efficiently, fluid can back up into the veins that take blood through the lungs to the left atrium. This then builds up the pressure in the blood vessels and fluid is pushed into the alveoli in the lungs. The fluid reduces normal oxygen movement through the lungs and can cause impaired gas exchange and respiratory failure. There are many causes of congestive heart failure that may lead to pulmonary edema such …

Enhancing Gan Led Efficiency Through Nano-Gratings And Standing Wave Analysis, Gabriel M. Halpin

Master's Theses

Improving energy efficient lighting is a necessary step in reducing energy consumption.Lighting currently consumes 17% of all U.S. residential and commercial electricity, but a report from the U.S. Office of Energy Efficiency and Renewable Energy projects that switching to LED lighting over the next 20 years will save 46% of electricity used in lighting.GaN LEDs are used for their efficient conversion of electricity to light, but improving GaN efficiency requires optically engineering the chip to extract more light.Total internal reflection limits GaN LED performance since light must approach the chip surface within 23.6° of normal to escape into air.This thesis …

Action Potential Simulation Of The Hirudo Medicinalis's Retzius Cell In Matlab, Zechari Ryan Tempesta

Master's Theses

Modification of Hodgkin and Huxley’s experimentally derived set of nonlinear differential equations was implemented to accurately simulate the action potential of the Hirudo Medicinalis’s Retzius cell in MATLAB under analogous conditions to those found in the Retzius cell environment. The voltage-gated sodium and potassium channel responses to changes in membrane potential, as experimentally determined by Hodgkin and Huxley, were manipulated to suit simulation parameters established by electrophysiological Retzius cell recordings. Application of this methodology permitted additional accurate simulation of the Hirudo Medicinalis’s P cell under analogous conditions to those found in the P cell environment. Further refinement of this technique …

Functional 3-D Cellulose & Nitrocellulose Paper-Based, Multiplex Diagnostic Platforms Without Coupling Agents, Mackenzie Elizabeth Tageson

Master's Theses

The purpose of this thesis was to demonstrate device functionality of 3-D paper-based, multiplex platforms, µPADs, without the use of coupling agents between layers. Previously, these platforms were fabricated with double-sided tape and cellulose powder to try to augment proper fluid routing, but difficulties with this method occurred. An acrylic housing unit with strategically placed pressure tabs was designed to aid horizontal and vertical fluid routing through the platform, thus eliminating the inconsistencies associated with coupling agents. Channel characterization studies, a COMSOL^TM simulation, and development time studies were performed to aid device design and demonstrate device functionality.

The implementation …

Formulation Development Of A Polymer-Drug Matrix With A Controlled Release Profile For The Treatment Of Glaucoma, Eric W. Tsoi

Master's Theses

Glaucoma is the leading cause of blindness in the United States accounting for 9-12% of all cases of blindness. Currently, the front line treatment for glaucoma are prostaglandins that may have to be taken up to several times a day. Even with proper treatment, roughly 11% of the patients using the treatment are non-compliant and lose their vision. In this project, ForSight Laboratories has developed a pharmaceutical drug delivering implant with the capability of sustaining long-term release of a prostaglandin as a new way to treat the condition. This project reports the product development of a polymer drug matrix with …

Analysis Of An Inflatable Gossamer Device To Efficiently De-Orbit Cubesats, Robert A. Hawkins Jr.

Master's Theses

There is an increased need for spacecraft to quickly and efficiently de-orbit themselves as the amount of debris in orbit around Earth grows. Defunct spacecraft pose a significant threat to the LEO environment due to their risk of fragmentation. If these spacecraft are de-orbited at the end of their useful life their risk to future spacecraft is greatly lessened. A proposed method of efficiently de-orbiting spacecraft is to use an inflatable thin-film envelope to increase the body's area to mass ratio and thusly shortening its orbital lifetime. The system and analysis presented in this project is sized for use on …

Numerical Flow Field Analysis Of An Air Augmented Rocket Using The Axisymmetric Method Of Characteristics, Jeffrey Massman

Master's Theses

An Axisymmetric Rocket Ejector Simulation (ARES) was developed to numerically analyze various configurations of an air augmented rocket. Primary and secondary flow field visualizations are presented and performance predictions are tabulated. A parametric study on ejector geometry is obtained following a validation of the flow fields and performance values.

The primary flow is calculated using a quasi-2D, irrotational Method of Characteristics and the secondary flow is found using isentropic relations. Primary calculations begin at the throat and extend through the nozzle to the location of the first Mach Disk. Combustion properties are tabulated before analysis to allow for propellant property …

Parsing Of Natural Language Requirements, Jamie L. Patterson

Master's Theses

The purpose of this thesis was to automate verification of the software requirements for an implantable cardioverter defibrillator with minimal manual rework. The requirements were written in plain English with only loose stylistic constraints. While full automation proved infeasible, many significant advances were made towards solving the problem, including a framework for storing requirements, a program which translates most of the natural language requirements into the framework, and a novel approach to parts of speech analysis.

Mechanical Properties Of Bone Due To Sost Expression: Nanoindentation Assessment Of Murine Femurs, Amir Rafie

Master's Theses

In the human genome, the SOST gene codes for a protein sclerostin. Sclerostin is an osteocyte-expressed negative regulator of bone formation. When the SOST gene is not coded, bone formation is reduced in individuals during skeletal maturation. This study utilizes nanoindentation methods to test for the mechanical properties of bones that both express and do not express the SOST gene. 100 transgenic murine femurs were obtained from Lawrence Livermore Labs in the form of 6 and 8 month SOST transgenic mice, 6 and 12 month SOST knockout mice, and wild type control littermates for each of the 4 age groups. …

Active Learning Using Model-Eliciting Activities And Inquiry-Based Learning Activities In Dynamics, Jeffrey Phillip Georgette

Master's Theses

This thesis focuses on a year-long project of implementing active learning in undergraduate dynamics courses at Cal Poly San Luis Obispo from 2012-2013. The purpose is to increase conceptual understanding of critical dynamics concepts and to repair misconceptions of the students. Conceptual understanding in Dynamics is vital to understanding the big picture, building upon previous knowledge, and better understanding the behavior of engineering systems. Through various hands-on activities, students make predictions, test their conceptions, and solve real world problems. These active learning methods allow students to improve their learning of Dynamics concepts. Education research on active learning is present in …

Design Of A Low Power Cargo Security Device Using A Micropower Ultra-Wideband Impulse Radar, Brian M. Wihl

Master's Theses

Each year, thousands of cargo containers are broken into during shipping, costing billions of dollars in lost and damaged goods. In addition to removing its contents, intruders can also add unwanted and dangerous materials to a container, posing a threat to National Security. The possibilities of cargo container break-ins require that the containers go through check points at which they are physically searched. These searches often require the opening of the container, unloading and inspecting all cargo, and then loading the container and resealing it. This is a long and costly process.

Because of the high costs of break-ins and …

Investigation Of Parameters Influencing Reverse Fault Rupture Propagation To The Ground Surface, Kevin V. Stanton

Master's Theses

Surface fault rupture poses a serious threat to infrastructure in many seismically active regions, but knowledge about the factors which control the likelihood of surface displacement is limited. Current probabilistic frameworks rely only on fault mechanism and moment magnitude to predict the probability of rupture to the ground surface. However, recent work has shown that there may be other parameters which also deserve consideration. For example, statistical analyses have demonstrated that variation in near surface material stiffness may significantly affect the probability of surface rupture over reverse faults. In addition, numerical investigations indicate that the rupture history of native soil …

Constant Voltage Hot-Wire Anemometry For The Boundary Layer Data System, Hon Yee Li

Master's Theses

To continue the development of the Boundary Layer Data System (BLDS), a constant voltage hot-wire anemometer (CVA) is implemented into the BLDS for flight-testing. The hot-wire anemometer was chosen as an alternative to the traditional pressure probe because of the ability to measure both average velocity and fluctuating velocity within the boundary layer. Previous work done on the benchtop has led to the design of miniaturization, flight-capable hardware for the BLDS. The next step in the development of the BLDS – CVA calls for quantifying the accuracy of the boundary layer measurements measured by the CVA system. To do this, …

Reassessment Of Biowish Activation Procedure For Denitrification, William Wah Yee

Master's Theses

BiOWiSH^TM – Aqua is a blend of preserved multi-bacteria culture with the capability of denitrification. If an anaerobic nitrate rich activation procedure is used instead of the standard aerobic activation procedure, the denitrification rate is increased by 28 percent under the conditions of 30°C, 1C:1N, 200mg/L of carbon, and 200mg/L nitrogen.

High Voltage Pulse Measurement System, Angelo J. Ballungay

Master's Theses

Using isolation and noise immunity techniques, this thesis designs and constructs a low cost measurement system to safely and accurately measure high voltage, high frequency pulses in harsh EM environments. High voltage pulses apply to medical, plasma, and food industries. The difficulty of accurately measuring high voltage pulses continues to pose an issue. Measuring high voltage systems can cause damage to the system, the measurement system, and the user. High voltage and high frequency pulses create a harsh environment of electromagnetic fields that can disrupt the circuitry of the measurement system and harm the user. Implementing isolation from the high …

Lipid Production By Microalgae Treating Municipal Wastewater, James Edward Kelley

Master's Theses

Microalgae hold much promise as a feedstock in liquid biofuel production. Lipid content of microalgae cells range from 30-80% dry weight of biomass. It is projected that microalgae can produce between 1,000-6,500 gallons/acre/year of oil. Currently, production of industrial algae operates in open raceway ponds that use minimal capital and energy inputs to culture algae. Raceway ponds can also be used to grow microalgae from municipal waste streams. Although high biomass productivity can be achieved in these systems, there remains a large production gap between large volumes of biomass cultivation and high lipid content from microalgae cells. Low lipid content …

Large-Displacement Lightweight Armor, Eric C. Clough

Master's Theses

Randomly entangled fibers forming loosely bound nonwoven structures are evaluated for use in lightweight armor applications. These materials sacrifice volumetric efficiency in order to realize a reduction in mass versus traditional armor materials, while maintaining equivalent ballistic performance. The primary material characterized, polyester fiberfill, is shown to have improved ballistic performance over control samples of monolithic polyester as well as 1095 steel sheets. The response of fiberfill is investigated at a variety of strain rates, from quasistatic to ballistic, under compression, tension, and shear deformation to elucidate mechanisms at work during ballistic defeat. Fiberfill’s primary mechanisms during loading are fiber …

Development And Validation Of A Human Hip Joint Finite Element Model For Tissue Stress And Strain Predictions During Gait, Jeffrey D. Pyle

Master's Theses

Articular cartilage degeneration, called osteoarthritis, in the hip joint is a serious condition that affects millions of individuals yearly, with limited clinical solutions available to prevent or slow progression of damage. Additionally, the effects of high-risk factors (e.g. obesity, soft and hard tissue injuries, abnormal joint alignment, amputations) on the progression of osteoarthritis are not fully understood. Therefore, the objective of this thesis is to generate a finite element model for predicting osteochondral tissue stress and strain in the human hip joint during gait, with a future goal of using this model in clinically relevant studies aimed at prevention, treatment, …

Hollow Plume Mitigation Of A High-Efficiency Multistage Plasma Thruster, Scott Alan Mcgrail

Master's Theses

Since 2000, a relatively new electric thruster concept has been in research, development, and production at Thales Electron Devices in Germany. This High Efficiency Multistage Plasma Thruster, or HEMPT, has promising lifetime capabilities due to its plasma confinement system. However, the permanent magnet system that offers this and other benefits also creates a hollow plume, where ions are accelerated at angles rather than up the thruster centerline, causing a dip in ion current along the centerline. A laboratory model, built at JPL, was run at Cal Poly to characterize this plume shape and implement a shield to restore a conical …

Investigation Into The Mitigation Of The Effects Of Uncertain Optical Degradation On An Interplanetary Solar Sail Mission Using A Single Model Update, Jordan Smiroldo

Master's Theses

The renewed academic interest in using solar sails as a source of spacecraft propulsion has been accompanied by a recent fervor of investigations into non-ideal and off-nominal sail performance considerations. One of the most influential considerations, uncertain optical degradation, has been shown to present significant trajectory design difficulties. This paper investigates the potential of using a mid-course degradation model update to mitigate the risk of missing the target destination in a sample 300 day Earth-Venus trajectory. Using a range of potential degradation profiles, it is shown that correcting in the first half of the mission is highly likely to result …

Effects Of Waste Placement Practices On The Engineering Response Of Municipal Solid Waste, Jason Taylor Cox

Master's Theses

An extensive laboratory and field investigation was conducted at Santa Maria Regional Landfill (SMRL) in Santa Maria, CA to determine the effects of waste placement practices on the engineering response of municipal solid waste (MSW). Laboratory and field testing was used to determine the engineering properties and monitor field response of MSW.

The specific gravity (G_s) of manufactured MSW (MMSW), fresh MSW (FMSW), and old MSW (OMSW) was determined experimentally using a modified version of standard soil testing procedures. Effects of particle size, compactive effort, and degradation on the specific gravity of waste were evaluated. Specific gravity …

Measuring The Counter/Assumption Model's Effect On Argumentation Quality, Evan D G Ovadia

Master's Theses

This thesis presents a new platform called See the Reason, built upon a tree- structured argumentation model called the Counter/Assumption model. In the Counter/Assumption model, a topic is posted first, then under that topic, reasons for and against, and for each reason, counterarguments, and for any counterargu- ment, more counterarguments. The model enables us to systematically determine whether a claim is “tentatively true” or “tentatively false,” in an effort to motivate people to make their side’s claims tentatively true and the opposing side’s claims tentatively false, thus encouraging conflict. Research suggests that debates with more conflict are better, so this …

Investigation Of Compressed Air Energy Storage Efficiency, James W. Keeney

Master's Theses

This study investigates Compressed Air Energy Storage (CAES) application in the

electrical power and transportation industries. Information concerning current CAES projects is

presented. A thorough thermodynamic analysis of the CAES process is completed; including

theoretical efficiency determination for several variants of the compression and expansion

processes. Industry claimed efficiencies ranging from 26% to 82% are presented and explained.

Isothermal and Isentropic efficiency baselines are developed. Energy density of compressed air

on both a mass and volume basis is compared to other energy storage methods. Best expected

efficiency of a hypothetical CAES system is determined to be 34% using currently achievable …

Mode I Fracture Toughness Of Eight-Harness-Satin Carbon Cloth Weaves For Co-Cured And Post-Bonded Laminates, Josh E. Smith

Master's Theses

Mode I interlaminar fracture of 3k 8-Harness-Satin Carbon cloth, with identical fill and weft yarns, pre-impregnated with Newport 307 resin was investigated through the DCB test (ASTM D5528). Crack propagations along both the fill and weft yarns were considered for both post-bonded (co-bonded) and co-cured laminates. A patent-pending delamination insertion method was compared to the standard Teflon film option to assess its applicability to mode I fracture testing. The Modified Beam Theory, Compliance Calibration method, and Modified Compliance Calibration method were used for comparative purposes for these investigations and to evaluate the validity of the proposed Equivalent Stiffness (EQS) method. …

Scale Model Shake Table Testing Of Seismic Earth Pressures In Soft Clay, Ron Edward Noche

Master's Theses

This research consists of scale model shake table tests to investigate the development of seismic earth pressures in soft clay. The soft clay was modeled after prototype San Francisco Bay Mud consisting of a mixture of kaolinite, bentonite, class C fly ash and water. A flexible walled testing container founded on a 1g shake table was used to house the model soil and mimic 1D site response. An array of accelerometers embedded in the model soil measure during an input earthquake motion.

A scale model wall is equipped with pressure sensors to measure the seismic earth pressures over the duration …

Development And Validation Of A Human Knee Joint Finite Element Model For Tissue Stress And Strain Predictions During Exercise, Spencer D. Wangerin

Master's Theses

Osteoarthritis (OA) is a degenerative condition of cartilage and is the leading cost of disability in the United States. Motion analysis experiments in combination with knee-joint finite element (FE) analysis may be used to identify exercises that maintain knee-joint osteochondral (OC) loading at safe levels for patients at high-risk for knee OA, individuals with modest OC defects, or patients rehabilitating after surgical interventions. Therefore, a detailed total knee-joint FE model was developed by modifying open-source knee-joint geometries in order to predict OC tissue stress and strain during the stance phase of gait. The model was partially validated for predicting the …

Cae Methods On Vibration-Based Health Monitoring Of Power Transmission Systems, Brian Fang

Master's Theses

This thesis focuses on different methods to analyze power transmission systems with computer software to aid in detection of faulty or damaged systems. It is split into three sections. The first section involves utilizing finite element software to analyze gear stiffness and stresses. A quasi-static and dynamic analysis are done on two sets of fixed axis spur gears and a planetary gear system using ABAQUS to analyze the stress, strain and gear mesh stiffness variation. In the second section, the vibrational patterns produced by a simple bevel gear system are investigated by an experiment and by dynamic modeling in ADAMS. …

A Software Development Kit For Camera-Based Gesture Interaction, Devlin Cronin

Master's Theses

Human-Computer Interaction is a rapidly expanding field, in which new implementations of ideas are consistently being released. In recent years, much of the concentration in this field has been on gesture-based control, either touch-based or camera-based. Even though camera-based gesture recognition was previously seen more in science fiction than in reality, this method of interaction is rising in popularity. There are a number of devices readily available to the average consumer that are designed to support this type of input, including the popular Microsoft Kinect and Leap Motion devices.

Despite this rise in availability and popularity, development for these devices …

Artist-Driven Fracturing Of Polyhedral Surface Meshes, Tyler Casella

Master's Theses

This paper presents a robust and artist driven method for fracturing a surface polyhedral mesh via fracture maps. A fracture map is an undirected simple graph with nodes representing positions in UV-space and fracture lines along the surface of a mesh. Fracture maps allow artists to concisely and rapidly define, edit, and apply fracture patterns onto the surface of their mesh.

The method projects a fracture map onto a polyhedral surface and splits its triangles accordingly. The polyhedral mesh is then segmented based on fracture lines to produce a set of independent surfaces called fracture components, containing the visible surface …