Digital Commons Network^™

Development Of A Human Tibiofemoral Joint Finite Element Model To Investigate The Effects Of Obesity And Knee Malalignment On Joint Contact Pressure, Meghan Sylvia

Master's Theses

Obesity is a known risk factor for osteoarthritis (OA). Excess body weight generates greater joint contact forces at the knee; however, obese individuals alter their gait to decrease joint contact forces. Knee malalignment has been identified as a strong mediating factor between obesity and knee OA progression. Excess body weight acting on a varus malaligned knee would have an additive effect on cartilage stress and could cause stress levels to exceed the threshold limit for damage and loss of cartilage matrix.

A finite element (FE) model of the human tibiofemoral joint was developed and validated in order to investigate changes …

Locating Optimal Water Quality Monitoring Locations Using Demand Coverage Index Method, Jeffrey Scott Brake

Master's Theses

Water quality regulations are always expanding especially in the field of water quality monitoring; however, threats to our water distribution systems still remain. Components of water distribution systems are susceptible to intentional and accidental contamination; therefore, they represent highly vulnerable aspects of our vital infrastructure.

An analysis was performed on a city in California with a population of 30,000 to 40,000 residents. The analysis is performed to determine the optimal locations of monitoring stations throughout the water distribution system. The method presented by Liu and colleagues (Liu et al, 2012) selects the optimal monitoring locations for the virtual California city …

Analysis Of Mos Current Mode Logic (Mcml) And Implementation Of Mcml Standard Cell Library For Low-Noise Digital Circuit Design, Marcus Edwin Allan Heim

Master's Theses

MOS current mode logic (MCML) offers low noise digital circuits that reduce noise that can cripple analog components in mixed-signal integrated circuits, when compared to CMOS digital circuits. An MCML standard cell library was developed for the Cadence Virtuoso Integrated Circuit (IC) design software that gives IC designers the ability to design complex, low noise digital circuits for use in mixed-signal and noise sensitive systems at a high level of abstraction, allowing them to get superior products to market faster than competitors. The MCML standard cell library developed and presented here allows for fast development of mixed signal circuits by …

The Development Of A High-Performance Distributed Battery Management System For Large Lithium Ion Packs, Christopher B. Grasberger

Master's Theses

A high performance battery management system (BMS) for large capacity cells was designed, built, and tested in a cycle of three revisions. The BMS was designed for use in applications where the battery pack configuration is unknown: parallel, series, or any combination. Each of the cells is equipped with its own battery management system to allow a peer-to-peer mesh network to monitor the safety of the cell. The BMS attached to each cell also is equipped with a 25A DC/DC converter to perform active balancing between cells in a string. This converter can transfer charge to (or from) a cell …

Hydrologic Response To Conifer Removal From An Encroached Mountain Meadow, Gregory F. Van Oosbree

Master's Theses

Meadows in the Sierra Nevada Mountains are an important ecological resource that have degraded in quality and distribution due to several environmental and anthropogenic stressors. The encroachment of conifers beyond forest meadow ecotones is largely responsible for the decline of meadow habitat throughout the past century. Currently, there is little research that quantifies the hydrologic response to removal of conifers encroaching meadows in terms of implicating successful meadow restoration. This study has implemented a before after control intervention (BACI) study design to determine the hydrologic response associated with the removal of conifers from a historic meadow encroached by conifers. The …

Fog Protocol And Fogkit: A Json-Based Protocol And Framework For Communication Between Bluetooth-Enabled Wearable Internet Of Things Devices, Spencer Lewson

Master's Theses

Advancements in technology have brought about a wide variety of devices, such as embedded devices with sensors and actuators, personal computers, smart devices, and health devices. Many of these devices are categorized as “wearables,” meaning that they are intended to be carried and used on one’s body. As this category increases in popularity and functionality, developers will need a convenient way for these devices to communicate with each other and store information in a standardized and ecient manner.

The Fog protocol and FogKit framework developed and demonstrated for this thesis address these issues by providing a set of powerful features, …

Analysis Of A Carbon Fiber Reinforced Polymer Impact Attenuator For A Formula Sae Vehicle Using Finite Element Analysis, John T. Rappolt

Master's Theses

The Hashin failure criteria and damage evolution model for laminated fiber reinforced polymers are explored. A series of tensile coupon finite element analyses are run to characterize the variables in the physical model as well as modeling techniques for using an explicit dynamic solver for a quasi-static problem. An attempt to validate the model on an axial tube crush is presented. It was found that fiber buckling was not occurring at the impactor-tube interface. Results and speculation as to why the failure initiation is incorrect are discussed. Lessons learned from the tube crush are applied successfully to the quasi-static Formula …

Increasing Isentropic Efficiency With Hydrostatic Head And Venturi Ejection In A Rankine Power Cycle, Nathan Daniel Ruiz

Master's Theses

This thesis describes the modifications made to the Cal Poly Thermal Science Laboratory’s steam turbine experiment. While the use of superheating or reheating is commonly used to increase efficiency in a Rankine cycle the methods prove unfeasible in a small scale project. For this reason, a mathematical model and proof of concept design using hydrostatic head generated by elevation and venturi ejection for use by the condenser is developed along with the equations needed to predict the changes to the system. These equations were used to create software to predict efficiency as well as lay down the foundation for future …

Sudden Cardiac Arrest Prediction Through Heart Rate Variability Analysis, Luke Joseph Plewa

Master's Theses

The increase in popularity for wearable technologies (see: Apple Watch and Microsoft Band) has opened the door for an Internet of Things solution to healthcare. One of the most prevalent healthcare problems today is the poor survival rate of out-of hospital sudden cardiac arrests (9.5% on 360,000 cases in the USA in 2013). It has been proven that heart rate derived features can give an early indicator of sudden cardiac arrest, and that providing an early warning has the potential to save many lives. Many of these new wearable devices are capable of providing this warning through their heart rate …

Measuring The Influence That Components Have On Pedestrian Route Choice In Activated Alleys, Samuel Hirsher Gross

Master's Theses

This paper explores how cities have integrated formal planning into improving public space. Through a review of literature on the topic, this the paper identifies the potential design has to renovate narrow streets and alleys, within the public right of way. By preforming an assessment of plans and programs, this paper identifies the common themes or components that have been used by planners, architects, and engineers to improve the urban environment for pedestrians. Based on this information, a pilot study was created to measure the influence the most common components have on pedestrian route choice. The results are then compared …

Psychosocial Motivators For Obstacle Course Racing: A Qualitative Case Study, Aracely Rodriguez

Master's Theses

This study explored the psychological and sociological motivations of adult female and male obstacle course racers. A qualitative case study approach was used to explore the views, experiences, and motivations of obstacle course racing (OCR) participants. Descriptive statistics and cross tabulation was used to interpret responses to the 297 online questionnaires. A content analysis approach was used to analyze the qualitative data gathered from three focus groups with a total of 20 obstacle course racers. Three theories formed the basis of the study: Self-Determination Theory (SDT), Achievement Goal Theory (AGT), and Social Leaning Theory (SLT). Overall, findings supported previous research …

Adaptive Automotive Lighting Systems, Marc W. Haeberlin

Master's Theses

Over the past few years, the use of LEDs within the automotive and avionic industries has increased due to their high efficiency, durability and wide range of light brightness. As the use of LEDs within these industries grows, a need for reliable, high performance drivers becomes more relevant. Companies are implementing LEDs for applications involving adaptive lighting or simple dimming features. This thesis shows implementation of various non-isolated analog converters integrated with digital dimmers to achieve these adaptive lighting systems. Adaptive lighting systems involve reading an input from an external source (brake pedal or steering wheel) and changing the brightness …

Growth, Mortality, And Reproductive Potential Of California Halibut (Paralichthys Californicus) Off Central California, Cheryl L. Barnes

Master's Theses

Differences in key biological processes, such as growth and reproduction, can greatly influence localized population dynamics. Thus, it is important to evaluate intraspecific variation at several spatial scales to better understand biological limitations and develop management plans that maximize fishery sustainability. In 2011, the California Department of Fish and Wildlife (CDFW) conducted its first comprehensive stock assessment for California Halibut, Paralichthys californicus. However, limited life history data were available north of Point Conception. To improve our understanding of central California Halibut biology, 704 fish were collected during 2012 and 2013. Von Bertalanffy growth parameters were estimated at L∞ = 1041 …

Cytoflow Optics Analysis, Matthew Wayne Janke

Master's Theses

This project was founded by Cytoflow a flow cytometry company. The company’s aim is to make a custom cytometer that can be used by consumers. The purpose of this project was to create a design for the optics assembly of the cytometer. Prototypes were constructed and then tested to analyze results. Data was collected then analyzed using a specific standard across all cytometers. Using these guidelines a result was yielded that helped to improve the resolution of the system and decrease the size. Making the prototype more efficient and lower the cost. From the design review Cytoflow was able to …

The Creation, Analysis, And Verification Of A Comprehensive Model Of A Micro Ion Thruster, Maxwell J. Bodnar

Master's Theses

A computational model of the micro-ion thruster MiXI has been developed, analyzed, and partially verified. This model includes submodels that govern the physical, magnetic, electrostatic, plasma physics, and power deposition of the thruster. Over the past few years, theses have been conducted with the goal of running tests and analyzing the results; this model is used to understand how the thruster components interact so as to make predictions about, and allow for optimization of, the thruster operation. Testing is then performed on the thruster and the results are compared to the output of the code. The magnetic structure of the …

Nutrient Transformations In Algae Raceway Ponds Fed Municipal Wastewater, Carter Michael Reiff

Master's Theses

While treating domestic wastewater, algae can be grown and harvested for biofuel production. Water is a vital resource and it is imperative to conserve and reuse as much as possible. Several pilot and lab scale experiments were conducted to further research into a full scale wastewater treatment and biofuel production facility. This thesis will include these topics: nitrogen and phosphorus concentrations of clarified wastewater pond feed, nitrogen and phosphorus transformations by algae, and the potential of algae cell disruption technologies to increase nutrient solubilization.

The pilot scale experiments were conducted using nine 33 m², 0.3 m deep multi-culture …

Public Diplomacy For A Global World: The United States And Iran, Sarah A. Aghazadeh

Master's Theses

Complex global challenges – including environmental, economic, diplomatic, and health-related – span national boundaries and increasingly necessitate international cooperation. As a result, diplomacy has broadened from government-to-government relations to include government-to-public relations in an extended constituency of the global whole. Public diplomacy is a process by which governments attempt to attract and persuade various external publics to maintain relationships and encourage an environment for the approval of policies. Examining globalization, diplomacy, and power provides the foundation to assess a specific case of US public diplomacy with Iran. Systems theory provides a focus on the critical interactions, feedback processes, and relationships …

The Demise Of American Musical Theatre Of San Jose, Mike Scott Cymanski

Master's Theses

In 2008, American Musical Theatre (AMT) of San Jose filed for bankruptcy after more than 74 years in business. In this thesis, I identify the factors – both internal and external – that contributed to its demise. Interviews with former employees and board members were conducted, and newspaper articles, tax records, and internal documents were examined to explore factors such as management effectiveness, AMT’s relationship with its community, fundraising, the decline of the subscription model, unions, and venue problems. The conclusions of this case study have implications regarding the intersection that now exists between non-profit and for-profit performing arts in …

Human Impacts On Rocky Intertidal Gastropods: Are Marine Protected Areas Effective?, Cassie Bednar

Master's Theses

As the human population has exponentially increased, so have anthropogenic effects on the ocean including pollution, eutrophication, acidification, changes in sea level, and overfishing. The California coast is visited by millions of people every year and is subject to a range of impacts. In the near-shore marine environment, people collect intertidal gastropods for food, bait or recreation. Collecting these animals has caused a decline in body size because humans preferentially take the largest individuals. Marine protected areas (MPAs), established to protect marine resources, may serve to reduce impacts to species, including gastropods. I collected 2510 individual samples to determine the …

The Effect Of Post-Operative Analgesics On Ovarian Medullary Angiogenesis And Vasculogenesis, Shamus Martin Brady

Master's Theses

A critical factor for successful ovarian transplantation is the expeditious establishment of sufficient blood supply. Recommendations intended to improve recovery, reduce the effects of stress, and decrease the amount of pain for laboratory animals undergoing surgical procedures include post-operative analgesia. The two main types of drugs that are recommended for pain management are opioids and non-steroidal anti-inflammatory drugs (NSAIDs). Buprenorphine, an opioid, and meloxicam, an NSAID, are both widely used and have been shown to affect angiogenesis and vasculogenesis. This study was designed to examine the influence meloxicam and buprenorphine had on new blood vessel formation in the ovarian medullary …

Alfalfa Trap Cropping Increases Abundance Of Key Arachnids In An Organic Strawberry Agroecosystem, Sutapa Biswas

Master's Theses

Eighty three percent of the strawberries consumed in North America are grown in California, where the widespread use of insecticides has become hazardous to public health. The intensive use of pesticides for growing strawberries causes serious health risks to farm workers, in addition to contaminating the soil and groundwater. The cost to the environment and public health in the United States is estimated at $12 billion annually. Finding effective nontoxic management strategies for insect pests has become essential for long term sustainability. One strategy strawberry producers can use to promote sustainability is to increase the effectiveness of biological control techniques. …

Validation Of A Cfd Approach For Gas Turbine Internal Cooling Passage Heat Transfer Prediction, Daniel G. Wilde

Master's Theses

This report describes the development and application of a validated Computational Fluid Dynamics (CFD) modelling approach for internal cooling passages in rotating turbomachinery. A CFD Modelling approach and accompanying assumptions are tuned and validated against academically available experimental results for various serpentine passages. Criteria of the CFD modelling approach selected for investigation into advanced internal cooling flows include accuracy, robustness, industry familiarity, and computational cost.

Experimental data from NASA HOST (HOt Section Technology), Texas A&M, and University of Manchester tests are compared to RANS CFD results generated using Fluent v14.5 in order to benchmark a CFD modelling approach.

Capability of …

Universal Programmable Battery Charger With Optional Battery Management System, Michael Duke Desando

Master's Theses

This report demonstrates improvements made in battery charging and battery management technology through the design of a universal programmable battery charger with optional battery management system attachment. This charger offers improvements in charge efficiency and unique battery charging algorithms to charge a variety of battery chemistries with variety of power requirements. Improvements in efficiency result from a synchronous Buck Controller topology as compared to previous universal chargers that use asynchronous Buck-Boost Converter topologies. This battery charger also surpasses current universal battery chargers by offering different charge modes for different battery chemistries. Charge modes provide the user an option between extending …

Evaluation Of Design Tools For The Micro-Ram Air Turbine, Victor Fidel Villa

Master's Theses

The development and evaluation of the design of a Micro-Ram Air Turbine (µRAT), a device being developed to provide power for an autonomous boundary layer measurement system, has been undertaken. The design tools consist of a rotor model and a generator model. The primary focus was on developing and evaluating the generator model for the prediction of generator brake power and output electrical power with and without rectification as a function of shaft speed and electrical load, with only basic manufacturer specifications given as inputs. A series of motored generator evaluation test were conducted at speeds ranging from 9,000 to …

Consumer Evaluation: The Link Between Body Mass Index, Reward Sensitivity, Product Liking And Emotion, Malori Comer

Master's Theses

The objectives of this study were: (1) to evaluate consumer acceptance of cheeses varying in fat and sodium levels, (2) to determine if sensitivity to reward and body mass index has an effect on product liking based on fat or salt content, (3) to evaluate the use of FaceReader technology during consumer evaluation and, (4) to determine if consumer’s self-selected, conscious emotions matched with the expressed, subconscious emotions acquired by FaceReader.

Consumer acceptance testing (n=108) was conducted on two medium cheddar cheeses with varying fat levels and two low-moisture part-skim mozzarella cheeses varying in sodium levels. Attributes were measured using …

Virulence Gene Expression Of Vibrio Parahaemolyticus In The Viable But Nonculturable State, Tiffany Pui-Yun Tse

Master's Theses

Vibrio parahaemolyticus is a food-borne pathogen commonly associated with the consumption of raw or undercooked seafood resulting in primary infections of the human gastrointestinal tract. It is estimated to cause about 4500 illnesses each year in the United States. However, infection from this food-borne pathogen can be avoided if this organism is detected in the implicated food, prior to consumption. Current standard methods of detecting this organism are dependent on the culturability of the bacteria. Detection based on an organism’s culturability may be problematic as V. parahaemolyticus has been known to exist in a viable but nonculturable (VBNC) state. Bacteria …

Aerodynamic Design And Structural Analysis Procedure For Small Horizontal-Axis Wind Turbine Rotor Blade, Dylan R. Perry

Master's Theses

This project accomplished two correlated goals of designing a new rotor blade to be used with the Cal Poly Wind Power Research Center, as well as defining the methodology required for the aerodynamic analysis of an optimized blade, the procedure required for generation of an accurate CAD model for the new blade geometry, and structural integrity verification procedure for the new blade via finite element analysis under several operating scenarios. The new rotor blades were designed to perform at peak efficiency at a much lower wind speed than the current CPWPRC rotor blades and incorporated a FEA verification process which …

Ecg Classification With An Adaptive Neuro-Fuzzy Inference System, Brad Thomas Funsten

Master's Theses

Heart signals allow for a comprehensive analysis of the heart. Electrocardiography (ECG or EKG) uses electrodes to measure the electrical activity of the heart. Extracting ECG signals is a non-invasive process that opens the door to new possibilities for the application of advanced signal processing and data analysis techniques in the diagnosis of heart diseases. With the help of today’s large database of ECG signals, a computationally intelligent system can learn and take the place of a cardiologist. Detection of various abnormalities in the patient’s heart to identify various heart diseases can be made through an Adaptive Neuro-Fuzzy Inference System …

Designing A Visual Front End In Audio-Visual Automatic Speech Recognition System, Junda Dong

Master's Theses

Audio-visual automatic speech recognition (AVASR) is a speech recognition technique integrating audio and video signals as input. Traditional audio-only speech recognition system only uses acoustic information from an audio source. However the recognition performance degrades significantly in acoustically noisy environments. It has been shown that visual information also can be used to identify speech. To improve the speech recognition performance, audio-visual automatic speech recognition has been studied. In this paper, we focus on the design of the visual front end of an AVASR system, which mainly consists of face detection and lip localization. The front end is built upon the …

Gods And Gurus In The City Of Angels: Aimee Semple Mcpherson, Swami Paramananda, And Los Angeles In The 1920s, Amy Hart

Master's Theses

This project focuses on two case studies as representative examples of Los Angeles’ progressive tolerance in the period of the 1920s: The Pentecostal mega-church of Aimee Semple-McPherson, and the Vedanta Ashram of Swami Paramananda. Both religious institutions opened in Los Angeles in 1923, just thirteen miles away from each other, and continued to thrive side-by-side throughout the twentieth century until present day. Each religious figure spoke to a part of the growing Los Angeles population: McPherson’s staunchly Christian, emotionally-driven, Hollywood-style ministry appealed to a large number of Los Angeles natives and newly-arrived immigrants, rocketing the emerging Pentecostal denomination into nationwide …