Digital Commons Network^™

Extended-Use Ecg Monitor, Daniel Aaron Soski

Master's Theses

In this thesis, a prototype ECG monitor was developed that is integrated into an elastic shirt and takes a 3-lead ECG for over 5 days. The high-quality measurements can be used to identify markers indicative of various detrimental heart conditions. Measurements recorded by the device are encrypted and stored onto a micro-SD card. Current Holter monitors are expensive and have functional lives less than 48 hours; however, extended duration monitoring has been proven more useful in diagnosis. The device designed demonstrates that ECG measurements can be taken over longer durations without sacrificing quality, comfort, or device cost.

Determining Feasibility Of A Propulsionless Microsatellite Formation Flight Mission, Aaron Levis

Master's Theses

Benefits of developing missions with multiple formation flying spacecraft as an alternative to a traditional monolithic vehicle are becoming apparent. In some cases, these missions can lower cost and increase flexibility among other situational advantages. However, there are various limitations that are imposed by these missions that are centered on the concept of maintaining the necessary formation. One such limitation is that of the propulsion system required for each spacecraft. To mitigate the complexity and mass of the onboard propulsion, the pairing of electromagnetic actuators and differential drag to replace the functionality of a propulsive system is investigated. By using …

Tessellated Voxelization For Global Illumination Using Voxel Cone Tracing, Sam Thomas Freed

Master's Theses

Modeling believable lighting is a crucial component of computer graphics applications, including games and modeling programs. Physically accurate lighting is complex and is not currently feasible to compute in real-time situations. Therefore, much research is focused on investigating efficient ways to approximate light behavior within these real-time constraints.

In this thesis, we implement a general purpose algorithm for real-time applications to approximate indirect lighting. Based on voxel cone tracing, we use a filtered representation of a scene to efficiently sample ambient light at each point in the scene. We present an approach to scene voxelization using hardware tessellation and compare …

Prediction Of The Degradation Of Emerging Contaminants During Oxidative Treatment Via Analysis Of Reaction Rate Constants, Kellie Cochran

Master's Theses

Globally, water supplies are diminishing in quality while demand is continually increasing. The municipal water and wastewater sector has been paying increased attention to unregulated emerging organic contaminants. Advanced oxidation processes (AOPs), which produce hydroxyl radicles (•OH), have been developed and implemented to remove recalcitrant emerging contaminants left by conventional treatment processes. The current understanding of the removal efficacy of AOPs for emerging contaminants is limited. This study analyzes the ability of an AOP involving ozone and multi-walled carbon nanotubes (MWCNTs) in removing three specific emerging contaminants: caffeine, atrazine, and phenytoin, which were selected based on their persistence and ubiquity …

The Analysis And Study Of Power System Designs For Same Polytechnic College In Tanzania, Kevin Lum Hua

Master's Theses

The Mbesese Initiative for Sustainable Development (MISD) is a group aiming to help eliminate extreme poverty in Africa by creating educational opportunity. One project that the group is currently doing is to build Same Polytechnic College (SPC) in Tanzania. As part of the project, this thesis aims to study and analyze the electrical power system and distribution for the college. Based on the projected load profile of the college and high potential for solar generation in Tanzania, several different power systems utilizing local utility AC electricity and/or photovoltaic (PV) DC electricity are explored and simulated for their feasibility and performance. …

Preparation Of Supramolecular Amphiphilic Cyclodextrin Bilayer Vesicles For Pharmaceutical Applications, Kate E. Frischkorn

Master's Theses

Recent pharmaceutical developments have investigated using supramolecular nanoparticles in order to increase the bioavailability and solubility of drugs delivered in various methods. Modification of the carbohydrate cyclodextrin increases the ability to encapsulate hydrophobic pharmaceutical molecules by forming a carrier with a hydrophobic core and hydrophilic exterior. Guest molecules are commonly added to these inclusion complexes in order to add stability and further increase targeting abilities of the carriers. One such guest molecule is adamantine combined with a poly(ethylene glycol) chain. Vesicles are formed by hydrating a thin film of amphiphilic cyclodextrin and guest molecules in buffer solution that mimics physiological …

Orbital Optimization Of Interplanetary Trajectories With Environmental Perturbations, Eric S. Woods

Master's Theses

For a detailed analysis of orbital optimization, it is desired to incorporate a spacecraft environment model in order to have maximum confidence that the analysis will produce an accurate trajectory. Such a model requires the addition of orbital perturbations, or small forces acting on the spacecraft throughout its trajectory that can eventually accumulate in large distances over time. The optimization method that this thesis is concerned with is STOpS (Spacecraft Trajectory Optimization Suite), a Matlab optimizer created by Timothy J. Fitzgerald that utilizes an Island Model Paradigm with five different optimization algorithms. STOpS was originally built to model trajectories with …

Design And Verification Of A Labview Automated Antenna Radiation Pattern Measurement System, Dylan C. Bloom

Master's Theses

In 2014, Toyon Research Corporation donated a 6’x6’x8’ anechoic chamber to the Cal Poly EE department to advance student education in the areas of antennas and wireless communications. An anechoic chamber is a room designed to suppress electromagnetic radiation reflections so that accurate measurement of radio frequency (RF) systems such as wireless radios and antennas can take place. Despite the fact that Cal Poly already has a larger anechoic chamber, primarily used for antenna characterization, it is the purpose of this project to design, code, and equip the new chamber so that it performs at least as good, or better …

Evaluation Of Electrochemical And Laser Polishing Of Selectively Lasermelted 316l Stainless Steel, Julian R. Lohser

Master's Theses

Selective laser melting has shown incredible growth as a metallic additive manufacturing process in recent years. While it does provide many solutions and new ways to approach challenges, it does not come without issues of its own, namely, surface roughness. In the as-printed state, the surface roughness of selectively laser melted parts is unacceptable for use in engineering applications. Additionally, selective laser melting is used to produce complex geometries with hard to reach features, preventing conventional mechanical polishing from being successful. Therefore, it is necessary to evaluate non-mechanical polishing processes as treatments for surface roughness. In this study, electrochemical and …

Hydrologic Response To Conifer Removal And Upslope Harvest In An Encroached Montane Meadow, Noël C. Fie

Master's Theses

Meadows are crucial components to larger river watersheds because of their unique hydrologic and ecological functions. Due to climate change, over grazing, and fire suppression, conifer encroachment into meadows has accelerated. In some western regions, nearly half of all meadow habitat has been loss due to conifer encroachment. Restoration of these hydrologic systems requires tree removal. Many studies exist that address the issue of conifer encroachment in montane meadows, however, few studies focus on the role that conifer removal plays on the encroaching meadow. Furthermore, few studies exist that document the hydrologic change from conifer removal and further restoration steps, …

Using Gaze Tracking To Tackle Duplicate Questions On Community Based Question Answering Websites: A Case Study Of Ifixit, Pankti Gandhi

Master's Theses

The number of unanswered questions on Community based Question Answering (CQA) websites has increased significantly due to the rising number of duplicate questions. This is a serious problem, one that could lead to the decline of such beneficial websites.

This thesis presents novel avenues that use gaze tracking technology and behavioral testing to tackle this problem. Based on prior studies on web search behaviors, we assumed that adding contextual information (snippets) to proposed related questions displayed on the `Ask a Question' page of the CQA website iFixit would improve the asker experience and reduce their tendency to post a new …

Exploring The Concept Of A Deep Space Solar-Powered Small Spacecraft, Kian Guillaume Crowley

Master's Theses

New Horizons, Voyager 1 & 2, and Pioneer 10 & 11 are the only spacecraft to ever venture past Pluto and provide information about space at those large distances. These spacecraft were very expensive and primarily designed to study planets during gravitational assist maneuvers. They were not designed to explore space past Pluto and their study of this environment is at best a secondary mission. These spacecraft rely on radioisotope thermoelectric generators (RTGs) to provide power, an expensive yet necessary approach to generating sufficient power. With Cubesats graduating to interplanetary capabilities, such as the Mars-bound MarCO spacecraft, matching the modest …

Pink And Dude Chefs: Effectiveness Of An After-School Nutrition Knowledge And Culinary Skills Program For Middle School Students To Increase Fruit And Vegetable Consumption, Alyssa S. Vaziri

Master's Theses

The rate of overweight and obesity among adolescents aged 12-19 years has more than tripled since 1980, and disproportionately impacts low-income and marginalized populations. Reduction in adolescent obesity rates may result in decreased health risks, decrease healthcare costs, and increased quality of life. Effective intervention methods for adolescent participants have incorporated nutrition knowledge and culinary skill building into afterschool programs. This study examines whether building knowledge, skills, and confidence through a culinary intervention can improve adolescent participants’ choices of healthful foods through increased fruit and vegetable intake.

Pink and Dude Chefs (PDC) is an afterschool nutrition education and culinary skills …

Neuro-Silicon Interface Of A Hirudo Medicinalis Retzius Cell Integrated With Field Effect Transistor, Kurt Christian Sjoberg

Master's Theses

The focus of this thesis was to measure the intracellular voltage of a living neural cell using a silicon transistor. The coupling of neurological tissues with silicon devices is of interest to the fields of neurology, neuroscience, electrophysiology and cellular biology. In previous work by Peter Fromherz, single neurons were successfully coupled to transistors [1]. This thesis aims to show proof of concept of the fabrication of a simple neuro-silicon interface using wafer processing methods currently available at Cal Poly. The types of transistors and cells used, the methods for dissecting and preparing the cells, the electrophysiology methods for validating …

Characterization Of Arterial Flow For Junctional Bleeding Control, Nick Bosio

Master's Theses

This study investigated reducing volumetric flowrate under steady flow conditions by varying lengths of compression with constant cross-sectional area and varying cross-sectional area reduction with constant length in order to better understand how to control junctional hemorrhaging. The hypotheses of this study were that length reduction will have little effect on volumetric flowrate and that cross-sectional area reduction would need to be approximately 80 percent in order to obtain bleeding control. The study found that length reduction has little effect on changing the flowrate. However, in order to obtain at least 80 percent reduction in flow, the area needs to …

Validation Of A 1d Algorithm That Measures Pulse Wave Velocity To Estimate Compliance In Blood Vessels, James Leung

Master's Theses

The purpose of this research is to determine if it is possible to validate the new 1D method for measuring pulse wave velocity in the aorta in vivo and estimate compliance. Arterial pressure and blood flow characterize the traveling of blood from the heart to the arterial system and have played a significant role in the evaluation of cardiovascular diseases. Blood vessel distensibility can give some information on the evolution of cardiovascular disease. A patient’s aorta cannot be explanted to measure compliance; therefore we are using a flow phantom model to validate the 1D pulse wave velocity technique to estimate …

Nutrient Removal In Microalgae Raceway Ponds And Nitrification Modeling, Esmeralda Diego

Master's Theses

This thesis explores the treatment of municipal wastewater using pilot-scale raceway ponds and looks specifically at the capability of the raceways in removing BOD and nitrogen. Nine 33 square-meter algal raceway ponds were used to conduct research at the San Luis Obispo Water Resources Recovery Facility. Main objectives of this study were to increase the removal of total ammonia nitrogen (NH₃-N plus NH₄⁺-N) from municipal wastewater through increased assimilation and nitrification. Raceway ponds with CO₂ addition were operated in series with an intermediate settling step and a total hydraulic retention time (HRT) of 4 …

Automated Pruning Of Greenhouse Indeterminate Tomato Plants, Joey M. Angeja

Master's Theses

Pruning of indeterminate tomato plants is vital for a profitable yield and it still remains a manual process. There has been research in automated pruning of grapevines, trees, and other plants, but tomato plants have yet to be explored. Wage increases are contributing to the depleting profits of greenhouse tomato farmers. Rises in population are the driving force behind the need for efficient growing techniques. The major contribution of this thesis is a computer vision algorithm for detecting greenhouse tomato pruning points without the use of depth sensors. Given an up-close 2-D image of a tomato stem with the background …

Comparative Analysis Of Physiological Measurements And Environmental Metrics On Predicting Heat Stress Related Events, Mckenzie Lee Barlow

Master's Theses

Exposure to high heat and humidity can lead to serious health risks, including heat exhaustion and heat stroke. Wet Bulb Globe Temperature (WBGT) and heat index have historically been used to predict heat stress events, but individualized factors are not included in the measurement. It has been shown that there is a relationship between cardiovascular measurements and heat stress, which could be used to measure heat stress risk on an individual level. Research has been done to find relationships between cardiovascular metrics in a workplace environment, however the study did not include the use of a controlled environment as a …

Investigation On The Dissociative Photoionization Mechanism Of Furfural, Investigation Of The Absolute Photoionization Cross Sections Of Three Potential Propargylic Fuels, And Ab Initio Analysis On Potential Superbases Of Several Hyperlithiated Species: Li3f2o And Li3f2(Oh)N (N = 1, 2, 3), Matthew Winfough

Master's Theses

This thesis presents the study photoionization cross sections of three different propargylic biofuels; dipropargyl ether, propargyl alcohol, and propargylamine, in chlorine radical-initiated combustion experiments at the Chemical Dynamics Beamline (9.0.2) at the Advanced Light Source of the Ernest Orlando Berkeley National Laboratory in Berkeley, California. Additionally, the unimolecular dissociative photoionization mechanism of furfural was studied using photoelectron photoionization coincidence (PEPICO) spectroscopy at the vacuum ultraviolet beamline at the Swiss Light Source of the Paul Scherrer Institut in Villigen, Switzerland. Dissociation products and mechanisms for furfural were identified over a photon energy range of 10.9 to 14.5 eV. Lastly, a study …

The Dissolution Of Diatoms In Marine Microbial Mats, Almariet Palm

Master's Theses

Microbial mats are self-contained organosedimentary ecosystems that played an important role in the evolution of early life on Earth. Understanding the conditions of their formation and preservation in the fossil record could provide valuable insights into microbe-mineral interactions and paleoenvironmental reconstruction. Diatoms are found at the surface of extant microbial mats, but their frustules are not observed at depth and rarely in fossil microbialites, which suggest their frustules dissolve. The objective of this study is to investigate the role of cyanobacterial photosynthesis, which locally elevates pH, in the dissolution of diatoms frustules. Field data and laboratory studies determined the effect …

Barriers To Dental Care For Children With Autism Spectrum Disorders, Nidhi Taneja

Master's Theses

Aims: To investigate barriers to dental care for children with autism spectrum disorder (ASD) from dentists’ and caregivers’ perspective.

Methods: This paper documents two cross sectional surveys of barriers to treating children with ASD. 109 general dentists were surveyed at a national conference in study 1, of whom about 74% reported treating children with ASD. In study 2, 83 caregivers were surveyed in hospital clinics, 46 of whom had a child with ASD, and 37 had children without ASD, and acted as a control group. Results: The most commonly endorsed barriers perceived by general dentists were: lack of guidelines …

Security Dilemma In U.S.-China Relations: A Non-Traditional Security Studies Perspective, Jessica Tran

Master's Theses

Since Former President Barack Obama’s announcement of the Pacific Pivot in 2011, the security dilemma in U.S.-China relations have worsened considerably. Under President Donald Trump’s administration, the shifting of U.S. military focus to the Asia-Pacific region is expected to continue. As the U.S. moves forward with increasing its military presence in the Pacific to counter a perceived “aggressive” China, it may lead to serious consequences. This thesis presents the argument that China’s conception of national security includes the defense of the state from both foreign and domestic threats. Therefore, China’s military developments and policies are not strictly in response to …

Do Climate Shocks Affect Smallholder Farmers’ Conservation Practices? Evidence From Peru, Heleene Tambet

Master's Theses

Peruvian agriculture is estimated to be subject to the greatest impacts of climate change in South America. Resulting shifts in rainfall patterns and extreme temperature realizations impose more frequent abnormal weather shocks on farmers and their production decisions. I study the impact of such shocks on agricultural practice choices of farmers growing two main staples, maize and potato; namely, I analyze adoption of practices reducing soil degradation, practices aimed towards water conservation, and application of inorganic fertilizer. I utilize unique cross-sectional data from Peru National Agricultural Survey over the years 2014 to 2016 in conjunction with long-term climate data, and …

Bi Or Multilingualism And Its Curriculum For Children With Sli, Jeongmin Ryou

Master's Theses

The purpose of this project, which is based on SLI children age 3-6, is to inspect the possibility of bi- or multilingualism on SLI children and to create a curriculum, which consists of six modules, accordingly. It includes a variety of visual and auditory materials for each module, offers well-tailored daily lesson, and helps children with SLI learn the target language simply and easily. This project provides tips for teachers and can be also referenced when a teacher creates his or her own curriculum. Each module is flexible and should be tailored to the individual, while also being facilitated to …

Crosslinguistic Influence Of Chinese Efl Learners On English Acquisition, Weijia Tang

Master's Theses

This thesis introduces both positive and negative crosslinguistic influence of Chinese EFL learners on English Acquisition. Most Chinese EFL learners have difficulties in English acquisition due to the negative crosslinguistic influence caused by the differences between mother tongue and the target language. In order to help Chinese EFL learners to tackle this problem, comparative analysis is done between English and Mandarin Chinese in terms of phonetics and phonology, morphology, part syntax, and pragmatics.

The focus of this thesis is to investigate both the positive and negative crosslinguistic influence phenomena in the process of English acquisition conducted by Chinese EFL learners …

Opportunities Beyond High School: An Eld Unit For Newcomer Students, Karen Toepp

Master's Theses

As an English Language Development (ELD) teacher, I noticed the junior newcomer students at my high school in the Bay Area of California were not being prepared for jobs or careers after their graduation. As newcomers, they are working through trauma, reuniting with their families, learning a new language and adapting to a new culture. Though many arrived with high expectations for school, students stopped connecting graduating high school with having access to higher education, which meant more job training and better employment opportunities. A lack of motivation and unskilled teachers contributed to students struggling in school and leading to …

Boosting Demand For Biofortified Foods: The Case Of Orange Fleshed Sweet Potato Bread In Tamale, Ghana, Tchassanty Ouro-Gbeleou

Master's Theses

Abstract: In the context of introducing biofortification of staple crops as a food-based approach to combat micronutrient malnutrition in Sub Saharan Africa (SSA), we carried out a survey in Tamale, Ghana to elicit consumers’ preference of and willingness to pay for one of the highly nutritious biofortified staple crop processed product: the Orange Fleshed Sweet Potato (OFSP) bread. Our results indicate that scores of respondents in the sample show preference for OFSP bread. The most important determinants of OFSP bread preference are its sweet taste and soft texture and consumers are willing to pay 0.634 pesewas more for the attribute …

An Economic Valuation Of Biodiversity: Measuring Willingness-To-Pay For Quinoa Conservation In Peru, Craig Scott

Master's Theses

Peru is facing increasing homogenization of traditional crops as a result of international market pressures. Destruction of the genetic resource base creates vulnerability to disease, climate, and pest shocks which threaten food security and the economic future of Peru’s agricultural sector. This paper aims to determine whether informational priming on the non-market value of national identity is sufficient to change the willingness to pay for agro biodiversity programs among the Peruvian general population in both urban and rural areas. A choice set willingness to pay experiment combined with choice rankings and randomized priming measures how much individuals are willing to …

Public Policy And Millennium Development Challenges: Case Study Of Africa, Pathkonn Kombate

Master's Theses

Abstract:

Based on a panel of 50 African countries from 1970 to 2015, this study analyzes the impact of public investments and spending in education and health sectors on GDP per capita growth. I separately modeled for education and health capital, while controlling for governance and demonstrated the importance of investments and expenditures on human capital in countries production capacity accumulation, which in the long run leads sustainable economic growth. Results show a positive relationship between spending in those sectors and the per capita income growth and proves their importance on the continents’ combat against poverty.