Engineering Commons^™

Vibration Health Monitoring Of Gears, Markus Josef Scherer

Master's Theses

Monitoring the health of vibrating gears is important to ensure proper operation especially in potentially life-threatening structures, such as helicopters, nuclear power plants, and uninterruptible power supply transitions in hospitals. The most common monitoring technique is casing mounted accelerometers to measure vibration. In contrast, during the last few years acoustic monitoring techniques have also provided a few diagnostic methods for gear failure. Current diagnostic methods to indicate improper gear behavior use either existing vibration data, recorded from defective gear systems, or modern dynamic models predicting gear failure behavior.

This thesis uses dynamic models to indicate, predict, and diagnose healthy and …

Performance-Based Analysis Of A Reinforced Concrete Shear Wall Building, Garrett Richard Hagen

Master's Theses

PERFORMANCE-BASED ANALYSIS OF A REINFORCED CONCRETE SHEAR WALL BUILDING

Garrett Richard Hagen

In this thesis, a special reinforced concrete shear wall building was designed per ASCE 7-05, and then the performance was investigated using the four analysis procedures outlined in ASCE 41-06. The proposed building was planned as a 6-story office building in San Francisco, CA. The structural system consisted of a two-way flat plate and reinforced concrete columns for gravity loads and slender structural walls for seismic loads. The mathematical building models utilized recommendations from ASCE 41-06 and first-principle mechanics. Moment-curvature analysis and fiber cross-section elements were used in …

Development Of A Ground Based Atomic Oxygen And Vacuum Ultraviolet Radiation Simulation Apparatus, Max Jay Glicklin

Master's Theses

The space environment possesses numerous unique and unusual attributes, creating challenges that must be considered in order to accomplish a successful space mission. Two of the detrimental aspects of the space environment include Atomic Oxygen, AO, and Ultraviolet, UV, radiation. UV radiation becomes more severe in space as there is no atmosphere to attenuate incoming photons, thereby exposing spacecraft to radiation that never reaches the surface of the Earth. Overall, space vehicles are exposed to a total of 107.4 Watts/m² of light shorter than 400 nm. AO is created by the photo disassociation of molecular oxygen by UV radiation …

A Kinetic Study Of Anti-Vegf-A Polyclonal Antibodies And Anti-Vegf-A Ssdna Aptamers, Heather A. Hedeen

Master's Theses

A new detection reagent that could possibly augment or replace antibodies research and diagnosis methods are aptamers. Aptamers are ssDNA, RNA or polypeptide constructs that function like active antibodies. Antibodies and aptamers both specifically bind to selected target molecules, and as such they enable the detection or targeting of the presence or absence of a specific antigen.

In order to ensure that ssDNA aptamers perform similarly to antibodies, anti-VEGF-A polyclonal antibody and anti-VEGF-A ssDNA aptamer were evaluated against vascular endothelial growth factor A (VEGF-A) using Surface Plasmon Resonance (SPR). It was hypothesized that the anti-VEGF-A aptamer had the same, if …

Uniting The Nation's Power Grids: Opening Markets To Integrate Large Scale Renewable Power, Jeffrey Kenneth Wilkinson

Master's Theses

As renewable energy becomes increasingly cost competitive and Renewable Portfolio Standards (RPS) push states to produce more and more of their steadily growing power demands from renewable sources, the need to solve the problems associated with renewable penetration becomes a priority. The intermittent nature of solar and wind power generation require additional cost that inhibit their implementation as penetration levels grow. Reliability remains power utilities' top priority while they struggle to upgrade their systems. Old generation facilities will be decommissioned, renewable energy projects will come on line and transmission upgrades become inevitable. Variability on the grid is currently mitigated through …

Design Of Dc Light Bulb For The Dc House Project, Kent Chin Liang

Master's Theses

This thesis focuses on the design and implementation of an economical and energy efficient DC Light Bulb for the DC House Project. For the DC lighting system, emphasis is on the DC-DC LED driver, dimmer circuit, LED lighting array, and physical packing design. In this paper, a DC Light Bulb is designed, simulated, and tested to operate at a wide input voltage ranging from 24 VDC to 72 VDC, to be fully dimmable using pulse-width modulation technique, and to produce lumination intensities equivalent to a standard 100 W A19 incandescent light bulb at one-tenth the total power consumption. The DC …

Reliable Software Updates For On-Orbit Cubesat Satellites, Sean Fitzsimmons

Master's Theses

CubeSat satellites have redefined the standard solution for conducting missions in space due to their unique form factor and cost. The harsh environment of space necessitates examining features that improve satellite robustness and ultimately extend lifetime, which is typical and vital for mission success. The CubeSat development team at Cal Poly, PolySat, has recently redefined its standard avionics platform to support more complex mission capabilities with this robustness in mind. A significant addition was the integration of the Linux operating system, which provides the flexibility to develop much more elaborate protection mechanisms within software, such as support for remote on-orbit …

Linear Power-Efficient Rf Amplifier With Partial Positive Feedback, Matthew E. King

Master's Theses

Over the last decade, the number of mobile wireless devices on the market has increased substantially. New “multi-carrier” modulation schemes, such as OFDM, WCDMA, and WiMAX, have been developed to accommodate the increasing number of wireless subscribers and the demand for faster data rates within the limited commercial frequency spectrum. These complex modulation schemes create signals with high peak-to-average power ratios (PAPR), exhibiting rapid changes in the signal magnitude. To accommodate these high-PAPR signals, RF power amplifiers in mobile devices must operate under backed-off gain conditions, resulting in poor power efficiency. Various efficiency-enhancement solutions have been realized for backed-off devices …

Nitrocellulose Paper Based Microfluidic Platform Development And Surface Functionalization With Anti-Ige Aptamers, Jennifer Guerin Ward

Master's Theses

The purpose of this thesis project was to demonstrate the ability to utilize the capabilities of aptamers so that they may act as capture reagents for paper microfluidic devices. Several characterization experiments were conducted as a precursor before the final experimentation was performed. Paper characterization, manufacturing protocols for printing and heating, as well as 3D chip fabrication were all performed and analyzed. The results confirmed that the control of fluid through a 3D microfluidic device based in nitrocellulose is possible.

For the biochemistry portion of this thesis report, antibodies and aptamers were chosen to react with IgE, an antibody that …

Energy Harvesting From Elliptical Machines: Dc-Dc Converter Design Using Sepic Topology, Martin Kou

Master's Theses

Cal Poly’s ongoing Energy Harvesting from Exercise Machines (EHFEM) project is a very convenient and cost-effective way for generating DC power from physical exercise and sending it back to the electrical grid as AC power, providing a renewable energy source for the future. The EHFEM project consists of numerous subprojects involving converting different types of exercise machines for power generation. This project is a continuation of one of the previous subprojects, specifically involving an elliptical machine, and focuses on improving system functionality at different machine settings without altering the elliptical user’s experience by selecting a new DC-DC converter design, while …

Improvement Of Statistical Process Control At St. Jude Medical's Cardiac Manufacturing Facility, Christopher Lance Edwards

Master's Theses

Sig sigma is a methodology where companies strive to reproduce results ending up having a 99.9996% chance their product will be void of defects. In order for companies to reach six sigma, statistical process control (SPC) needs to be introduced. SPC has many different tools associated with it, control charts being one of them. Control charts play a vital role in managing how a process is behaving. Control charts allow users to identify special causes, or shifts, and can therefore change the process to keep producing good products, free of defects.

There are many factories and manufacturing facilities having implemented …

Impedance Sensing Of N2a And Astrocytes As Grounds For A Central Nervous System Cancer Diagnostic Device, Fraser Traves Smith Grove

Master's Theses

This thesis utilizes previously described manufacturing and design techniques for the creation of a PDMS-glass bonded microfluidic device, capable of electrochemical impedance spectroscopy (EIS). EIS has been used across various fields of research for different diagnostic needs. The major aim of this thesis was to capture cancerous and non-cancerous cells between micron sized electrodes within a microfluidic path, and to complete analysis on the measured impedances recorded from the two differing cell types. Two distinct ranges of impedance frequency were analyzed – the α dispersion range, which quantifies the impedance of the membranes of the cells of interest, and the …

Lottery Scheduling In The Linux Kernel: A Closer Look, David Zepp

Master's Theses

This paper presents an implementation of a lottery scheduler, presented from design through debugging to performance testing. Desirable characteristics of a general purpose scheduler include low overhead, good overall system performance for a variety of process types, and fair scheduling behavior. Testing is performed, along with an analysis of the results measuring the lottery scheduler against these characteristics. Lottery scheduling is found to provide better than average control over the relative execution rates of processes. The results show that lottery scheduling functions as a good mechanism for sharing the CPU fairly between users that are competing for the resource. While …

A Proposed Control Solution For The Cal Poly Wind Energy Capture System, Kent R. Burnett

Master's Theses

The focus of this thesis is to research, analyze, and design a reliable and economical control system for the Cal Poly Wind Energy Capture System (WECS). A dynamic permanent magnet generator model is adopted from [1] and [2] and combined with an existing wind turbine model to create a non-linear time varying model in MATLAB. The model is then used to analyze potentially harmful electrical disturbances, and to define safe operating limits for the WECS. An optimal operating point controller utilizing a PID speed loop is designed with combined optimization criteria and the final controller design …

A Model Predictive Control Approach To Roll Stability Of A Scaled Crash Avoidance Vehicle, Nikola John Linn Noxon

Master's Theses

In this paper, a roll stability controller (RSC) is presented based on an eight degree of freedom dynamic vehicle model. The controller is designed for and tested on a scaled vehicle performing obstacle avoidance maneuvers on a populated test track. A rapidly-exploring random tree (RRT) algorithm is used for the vehicle to execute a trajectory around an obstacle, and examines the geographic, non-homonymic, and dynamic constraints to maneuver around the obstacle. A model predictive controller (MPC) uses information about the vehicle state and, based on a weighted performance measure, generates an optimal trajectory around the obstacle. The RSC uses the …

Small-Scale Solar Central Receiver System Design And Analysis, Daniel Murray

Master's Theses

This thesis develops an analytical model of a small-scale solar central receiver power plant located at the California Polytechnic State University in San Luis Obispo, California at 35.28° N, 120.66° W. The model is used to analyze typical energy output at any time during the year. The power plant is designed to produce an output of 100 kW electrical power, and is supplemented by the combustion of natural gas. Methodologies for determining the proper size and layout of heliostats, optimal tower height, receiver size, and turbine engine selection are developed. In this specific design, solar shares of up to 73.2% …

Cuda Web Api Remote Execution Of Cuda Kernels Using Web Services, Massimo J. Becker

Master's Theses

Massively parallel programming is an increasingly growing field with the recent introduction of general purpose GPU computing. Modern graphics processors from NVIDIA and AMD have massively parallel architectures that can be used for such applications as 3D rendering, financial analysis, physics simulations, and biomedical analysis. These massively parallel systems are exposed to programmers through in- terfaces such as NVIDIAs CUDA, OpenCL, and Microsofts C++ AMP. These frame- works expose functionality using primarily either C or C++. In order to use these massively parallel frameworks, programs being implemented must be run on machines equipped with massively parallel hardware. These requirements limit …

Cubesat Mission Planning Toolbox, Brian Castello

Master's Theses

We are in an era of massive spending cuts in educational institutions, aerospace companies and governmental entities. Educational institutions are pursuing more training for less money, aerospace companies are reducing the cost of gaining ight heritage and the government is cutting budgets and their response times. Organizations are accomplishing this improved efficiency by moving away from large-scale satellite projects and developing pico and nanosatellites following the CubeSat specifications. One of the major challenges of developing satellites to the standard CubeSat mission requirements is meeting the exceedingly tight power, data and communication constraints.

A MATLAB toolbox was created to assist the …

Prediction Of Articular Cartilage Remodeling During Dynamic Compression With A Finite Element Model, Kevin Akira Yamauchi

Master's Theses

First, an in vitro growth experiment was performed to test the hypothesis that applying dynamic unconfined compression during culture produces het- erogeneous remodeling in newborn bovine articular cartilage explants. Het- erogeneous measures of cartilage microstructure were obtained by biochemical assays and quantified polarized light microscopy. Significant differences were measured between the GAG content in the inner and outer portions of the sam- ples stimulated with dynamic unconfined compression. The COL fiber network was found to be more highly aligned in the inner portion of the sample than in the peripheral region.

Next, a poroelastic finite element model with a remodeling …

Application Of A Heuristic Method To A Water Distribution System For Determining Optimal Water Quality Monitoring Locations, Lawrence David Johnson

Master's Theses

Although regulations and requirements for water quality source monitoring have increased, drinking water distribution systems can still be considered vulnerable to purposeful or accidental contamination.

This study analyzes the transport of the hypothetical contaminant Cryptosporidium through the distribution system of a city with a population of 30,000 to 50,000 in an attempt to locate the optimal monitoring locations in the distribution system. Cryptosporidium was selected due to its resistance to chlorine and it’s conservative properties for vulnerability assessments. The method for selecting the optimal monitoring locations was taken from Chastain (2004) which developed and examined the method for a virtual …

A New Computational Model To Augment The Design Of Microfluidic Separations: Electric Field Assisted, Hydrodynamic Chromatography, Jeffrey D. Wells

Master's Theses

This project encompasses the implementation of a computational model to simulate the microfluidic separation of like-charged particles in a continuous flow environment. By accomplishing this task the model can be used to optimize future fractionations by tailoring the process parameters to the properties of the target particles. The primary goal of this project is to develop a vectorized code within Matlab® that captures a sufficient quantity of the physics in separations to assist with the optimization and design of microfluidic systems.

This project differs from other computational models in that it utilizes a personal computer to run the simulation in …

Spectral Shape Division Multiplexing (Ssdm): Apparatus, Transmitter, Receiver And Detection, Fausto Daniel Holguín-Sánchez

Master's Theses

Wireless communication companies require to use the frequency spectrum to operate. Both frequency licenses and infrastructure to reuse frequencies are costly resources subject to increasing demand. This work introduces a novel multiplexing method that saves spectrum called Spectral Shape Division Multiplexing (SSDM). Under certain configurations, SSDM displays higher flexibility and throughput than other spectrally efficient methods.

SSDM defines the structure of a wireless multi-carrier by software. It is similar to Orthogonal Frequency Division Multiplexing (OFDM) in that both use overlapped sub-carriers to make efficient use of allocated spectrum. However, SSDM has several advantages. Where OFDM organizes sub-carriers orthogonally, SSDM allows …

Cascaded High Voltage Converter With Variable Control For Pulsed Electric Field Applications, Emmanuel Loza

Master's Theses

Living a sustainable lifestyle while facing increasing population and decreasing natural resources has become one of humanity’s largest challenges. Locating fossil fuels is becoming more difficult while the demand for them to power our societies is ever increasing. Instead of finding more efficient methods of extracting fossil fuels, developing technologies that create renewable substitutes for fossil fuels is now the strategy. Algae biofuel matches fossil fuel performance while also meeting the criteria for renewable energy. The focus now shifts to finding methods for commercially producing algae biofuel. Therefore, the objective of this thesis is to develop a system that provides …

Real-Time Musical Analysis Of Polyphonic Guitar Audio, John E. Hartquist

Master's Theses

In this thesis, we analyze the audio signal of a guitar to extract musical data in real-time. Specifically, the pitch and octave of notes and chords are displayed over time. Previous work has shown that non-negative matrix factorization is an effective method for classifying the pitches of simultaneous notes. We explore the effect of window size, hop length, and other parameters to maximize the resolution and accuracy of the output.

Other groups have required prerecorded note samples to build a library of note templates to search for. We automate this step and compute the library at run-time, tuning it specifically …

Feasibility Study Into The Use Of 3d Printed Materials In Cubesat Flight Missions, Daniel Fluitt

Master's Theses

The CubeSat Program has provided access to space for many universities, private companies, and government institutions primarily due to the low cost of CubeSat satellite development. While these costs are orders of magnitude lower than similarly capable nano-satellite missions, they are still outside of the budgetary constraints of many potential developers including university and high school clubs. Using 3D printed plastics in the production of CubeSat structures and mechanisms presents a large cost savings opportunity that will allow these institutions to participate in the development of these satellites, expanding the educational and scientific impact of the CubeSat Program.

Five rapid …

Implementation Of A ¼ Inch Hollow Cathode Into A Miniature Xenon Ion Thruster (Mixi), David Wayne Knapp

Master's Theses

Over the last decade, miniature ion thruster development has remained an active area of research do to its low power, low thrust, and high efficiency, however, due to several technical issues; a flight level miniature ion thruster has proved elusive. This thesis covers the design, fabrication, assembly, and test of an altered version of the Miniature Xenon Ion thruster (MiXI), originally developed by lead engineer Dr. Richard Wirz, at the California Institute of Technology (Caltech). In collaboration with Dr. Wirz, MiXI-CP-V3 was developed at Cal Poly San Luis Obispo with the goal of implementing of a ¼ inch hollow cathode …

Finite Element Modeling Of Ballistic Impact On A Glass Fiber Composite Armor, Dan M. Davis

Master's Theses

Finite Element Modeling of Ballistic Impact on a Glass Fiber Composite Armor

Dan Davis

Experiments measuring the ballistic performance of a commercially available fiberglass armor plate were used to guide the development of constitutive laws for a finite element model of the impact. The test samples are commercially available armor panels, made from E-glass fiber reinforced polyester rated to NIJ level III. Quasi-static tensile tests were used to establish material properties of the test panels. These properties were then used to create models in the explicit finite element code LSDYNA.

Ballistic impact testing of the panels was conducted using a …

The Characterization Of Biofilm Attachment To Metal Interfaces: Effects Of Substratum Properties, Marcel D. Mendes

Master's Theses

Bacteria are among the most abundant microorganisms on earth, and can be found in essentially every environment. When a clean surface is exposed to media containing planktonic bacteria, the bacterial cells will attach to the surface and aggregate to form what is known as a biofilm. Biofilms have been shown to negatively affect many industries including medical, industrial, and food science applications. While biofilms have been well characterized from a microbiology perspective, there has been much less research from a materials science standpoint. It is hypothesized that the material properties of the substratum (such as the micro-structure) have a significant …

Hapss, Hybrid Aircraft Propulsion System Synthesis, Michael W. Green

Master's Theses

Hybrid Aircraft Propulsion System Synthesis (HAPSS) is a computer program that sizes and analyzes pure-series hybrid electric propulsion systems for aircraft. The development of this program began during a NASA SBIR contract, in conjunction with Empirical Systems Aerospace (ESAero), with the creation of a propulsion fan design tool. Since the completion of this contract in July 2010, the HAPSS program has been expanded to combine the many aspects of a hybrid propulsion system such as the propulsive fans, electric motors, generators, and controllers, and the internal combustion engines.

This thesis describes the benefits and drawbacks of aircraft hybrid propulsion systems …

Preparation And Characterization Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Vascular Tissue Engineering And The Advancement Of An In Vitro Blood Brain Barrier Model, Deven Chandrakant Patel

Master's Theses

Developing an in vitro Blood Brain Barrier model that will replicate the physiological, anatomical, and functional characteristics of the native BBB has gained significant attention. Such a model would enable prediction of the penetration of CNS targeting drug candidates across the BBB, allow pre-screening and optimization strategies to be developed for new drugs and gene delivery formulations, and permit research groups to further understand how a dysfunctional BBB is involved in the pathogenesis of several neurological diseases.

The Tissue Engineering laboratory at the California Polytechnic State University, San Luis Obispo is currently in the process of developing a dynamic in …