Digital Commons Network^™

Development Of Reduced Chemistry For Efficient Combustion Simulations, Yufeng Liu

Master's Theses

Detailed chemical kinetics is important for high-fidelity reacting flow simulations. The major challenge of incorporation of detailed chemistry in large-scale simulations is primarily attributed to the high computational cost, induced by the large number of species and reactions, as well as the severe chemical stiffness. Methodologies are therefore needed to facilitate the use of detailed chemistry in large-scale combustion simulations. In the present study, a linearized error propagation (LEP) model is developed to eliminate unimportant species and reactions from detailed chemistry. In the LEP model, the reduction errors are analytically approximated and formulated for perfectly stirred reactors (PSR). The performances …

Investigating Simple Shear Mechanics Of Bovine Cartilage Using A Triaxial Shear Test Machine, Stephany Santos

Master's Theses

Objective: Articular cartilage is a non-homogeneous tissue with complex structure-function relationships. Damage to articular cartilage leads to traditionally irreparable conditions such as osteoarthritis, a disease that is both painful and debilitating to a large human population. The objective in this thesis is to perform triaxial mechanical tests on articular cartilage that are quasi-static and large-shear strains, in order to understand tissue mechanical behavior. Methods: Cartilage explants were taken from three healthy adult bovine femurs. Specimens were categorized by joint contact and contact stress regions with respect to the femoral condyle. Specimens were subject to applied shear parallel and perpendicular …

Effects Of Curing Cycle And Loading Rates On The Bearing Stress Of Double Shear Composite Joints, Mateja Andrejic

Master's Theses

In the last few decades, there has been a shift to using more lightweight materials for the potential of fuel consumption reduction. In the Aerospace Industry, conventional metal structures are being replaced by advanced composite structures. The major advantage of an advanced composite structure is the huge reduction in the number of parts and joints required. Also composite materials provide better resistance to creep, corrosion, and fatigue. However, one cannot eliminate all the joints and attachments in an aircraft’s structure. Eliminating structural joints is impractical in present-day aircraft because of the requirements for inspection, manufacturing breaks, assembly and equipment access, …

Multi-Level Analytic Network Process Model To Mitigate Supply Chain Disruptions In Disaster Recovery Planning, Martina Ursula Kroener

Master's Theses

Over the past few decades, environmental changes have led to more frequent occurrences and greater intensities of natural disasters worldwide. In terms of globally connected supply chains, this has resulted in an enormous economical loss for corporations. Therefore, Business Continuity and Disaster Recovery (BC/DR) planning and management has become essential for businesses in order to protect their critical business flow. Yet there is a lack of systematic and transparent methodologies for companies to handle this problem.

Hence, this thesis introduces a novel approach to combine consecutive steps of the Disaster Recovery Planning (DRP) process within one application. The multi-criteria decision-making …

Predicting Changes To Source Code, Justin James Roll

Master's Theses

Organizations typically use issue tracking systems (ITS) such as Jira to plan software releases and assign requirements to developers. Organizations typically also use source control management (SCM) repositories such as Git to track historical changes to a code-base. These ITS and SCM repositories contain valuable data that remains largely untapped. As developers churn through an organization, it becomes expensive for developers to spend time determining which software artifact must be modified to implement a requirement. In this work we created, developed, tested and evaluated a tool called Class Change Predictor, otherwise known as CCP, for predicting which class will implement …

Effect Of Reduced Sodium Cheese On The Growth Of Pathogenic Bacteria And Inactivation Of Listeria Innocua Using Supercritical Fluid Extraction With Co2, Suyapa Padilla Antunez

Master's Theses

Listeria monocytogenes continues to challenge the dairy industry in causing post-process contamination of cheeses. To reduce risk of contamination, it is crucial to understand the growth and survival of pathogenic bacteria in cheese products and to develop post-process mitigation strategies. This study evaluated the fate of pathogens in reduced and regular sodium Mozzarella cheese, and the potential of Supercritical Fluid Extraction with CO₂ (SFE) to reduce Listeria innocua on Mozzarella and Queso Fresco. The survival of L. monocytogenes, Salmonella, and E.coli O157:H7 (2-3 log CFU/g) in reduced sodium Mozzarella (1.62%), compared to regular sodium Mozzarella cheese (2.15%) …

Nutrition And Health-Related Quality Of Life In Older Adults In The Us, Nhanes 2009–2012, Jessica Anne Hews

Master's Theses

Few studies have investigated the relationship between diet quality and health-related quality of life (HRQOL), especially in the older adult population that is most at risk for poor diet and health. Self-perceived HRQOL is a more powerful predictor of morbidity and mortality than objective measures of health. The aim of this thesis was to examine the association between nutrition-related factors (especially diet quality) and HRQOL in community-dwelling older adults aged 60 and above. This research used cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 2009-2010 and 2011-2012 cycles to select and include diet quality variables, meal-related variables, …

The Taiwanese-American Perspective On Discrimination In English Language Teaching, Kuan Cheng Song

Master's Theses

This is a qualitative study examining the perspectives of five Taiwanese-American English teachers on their experiences of discrimination in the English language-teaching field of Taiwan. An extensive amount of literature has been written about the nativeness paradigm and its effect on the English language-teaching field, but the Taiwanese-American experience concerning those issues has yet to be explored. The study used Asian Critical Race Theory, Social Identity Theory and Asian American Racial Identity Theory to analyze the history of English language teaching in Taiwan, the critical studies on native and non-native English language teachers and the social issues affecting Asian Americans …

How Organizational Communication Shaped The Hearst Ranch Conservation Easement, Mo Tehrani

Master's Theses

The purpose of this study was to show how organizations involved with the Hearst Ranch Conservation Easement negotiations might have used the feedback loop characteristic of two-way Symmetrical communication theory to reach consensus on the Hearst Ranch Conservation Agreement.

Conservation easements are complex situations and each has separate and distinct goals, constraints, compromises, funding mechanisms, and public values.

This study analyzed public documents from seven different organizations that provided input in the public consultations regarding the Hearst Ranch Conservation Easement, which completed in 2005. This study concluded that one of the communication methods adopted during the Hearst Ranch Conservation Negotiation …

The Effect Of Xenon Pulsed-Light Technology On Biofilm Adhered To Stainless Steel Surfaces, Stephanie Jacquez

Master's Theses

In food processing, inadequate surface sanitation procedures lead to the formation of biofilms in which bacteria attach and aggregate in a hydrated polymeric matrix of their own synthesis. Formation of these sessile communities and their inherent resistance to existing sanitation procedures and agents are at the root of the risk of bacterial infections for consumers. Due to this existing problem, an effective method for reducing biofilm formation in dairy processing equipment is necessary for dairy products processing. Ultraviolet Pulsed light Technology has shown a positive effect in eliminating microorganism populations on food products. The objective of this work is to …

Pink And Dude Chefs: Impact Of A Nutrition And Culinary Education Program With Middle School Students In An Afterschool Setting, Jessie R. Bierlich-Wesch

Master's Theses

The epidemic of adolescent obesity has become one of the greatest public health concerns in the United States. Approximately 20.5% of adolescents of both sexes aged 12-19 years are considered obese. Higher rates of obesity are evident in ethnic minority and lower income status children with the highest prevalence among Hispanic/Latino and Black populations. The causes for obesity are multifactorial in nature and highlight disparities nationwide. These factors include socioeconomic status, education, environment, availability and access to fresh fruits and vegetables, and behavior patterns. Successful intervention methods that have reduced the impact of adolescent obesity have incorporated nutrition knowledge and …

Design And Validation Of A Fall Detection Application For Ios, Connor Lewis Mosley

Master's Theses

Despite significant preventative efforts, falls continue to be a major source of morbidity and mortality among the elderly. Additionally, the fear of falling can be a major obstacle to independent living for otherwise self-sufficient individuals. This fear is significantly heightened in individuals who have sustained a fall and often results in self-imposed restrictions on mobility and exercise, causing weakening in these individuals and further exacerbating the danger. Much time has been spent developing alert systems in an attempt to mitigate these problems. Unfortunately these systems typically involve dedicated monitoring centers and therefore often come with substantial upfront and recurring costs. …

Oceanographic Instrument Simulator, Amy Chen

Master's Theses

The Monterey Bay Aquarium Research Institute (MBARI) established the Free Ocean Carbon Enrichment (FOCE) experiment to study the long-term effects of decreased ocean pH levels by developing in-situ platforms [1]. Deep FOCE (dpFOCE) was the first platform, which was deployed in 950 meters of water in Monterey Bay. After the conclusion of dpFOCE, MBARI developed an open source shallow water FOCE (swFOCE) platform located at around 250 meter of water to facilitate worldwide shallow water experiments on FOCE [1][2]. A shallow water platform can be more ubiquitous than a deep-water platform as shallow water instruments are less expensive (as it …

Automated Vehicles: A Guide For Planners And Policymakers, Charlie Coles

Master's Theses

Automated vehicles are those which are capable of sensing their environments in order to perform at least some aspects of the safety-critical control (like steering, throttling, or braking) without direct human input. As a guide for planners and policymakers, the objective of this thesis is to develop a strong foundation for anticipating the potential impacts resulting from advancements in vehicle automation. To establish the foundation, this thesis uses a robust qualitative methodology, coupling a review of literature on the potential advantages and disadvantages of vehicle automation and lessons from past innovations in transportation, with recent trends of the Millennial Generation, …

Exploring Transit Ridership Using Census, Routing & Scheduling, And Stop Characteristic Data, Douglas Harvey Moody

Master's Theses

This study develops, analyzes, and a­­­­­pplies transit-system-specific regression tree models that identify and prioritize transit system improvements through analysis and application of ridership, Census, routing and scheduling, and transit stop characteristic data. Regression trees identify and rank independent variables that split dependent variable datasets into meaningful subsets according to significant relationships with independent variable datasets, and regression tree models can be used to identify and prioritize transit system improvements. In this study, ridership datatypes are the dependent variables (i.e., boardings and alightings) and Census, routing and scheduling, and transit stop characteristic datatypes are the independent variables. Data associated with the …

Evaluation Of Strength Reduction Factor For Concentrically Braced Frames Based On Nonlinear Single Degree-Of-Freedom Systems, Ryan Michael Slein

Master's Theses

Strength Reduction Factor (R-Factor), often referred to as Response Modification Factor, is commonly used in the design of lateral force resisting systems under seismic loading. R-Factors allow for a reduction in design base shear demands, leading to more economical designs. The reduction of strength is remedied with ductile behavior in members of proper detailing. Modern seismic codes and provisions recommend R-Factors for many types of lateral force resisting systems. However these factors are independent of the system fundamental frequency and many other important system properties, resulting in factors that may result in an unfavorable seismic response. To evaluate the validity …

Structural Damage Detection By Comparison Of Experimental And Theoretical Mode Shapes, William George Rosenblatt

Master's Theses

Existing methods of evaluating the structural system of a building after a seismic event consist of removing architectural elements such as drywall, cladding, insulation, and fireproofing. This method is destructive and costly in terms of downtime and repairs. This research focuses on removing the guesswork by using forced vibration testing (FVT) to experimentally determine the health of a building. The experimental structure is a one-story, steel, bridge-like structure with removable braces. An engaged brace represents a nominal and undamaged condition; a dis-engaged brace represents a brace that has ruptured thus changing the stiffness of the building. By testing a variety …

Development Of A Model And Optimal Control Strategy For The Cal Poly Central Plant And Thermal Energy Storage System, Daniel Douglas Castro

Master's Theses

This thesis develops a calibrated model of the Cal Poly Central Chilled Water Plant with Thermal Energy Storage for use in determining an optimal operating control strategy. The model was developed using a transient systems simulation program (TRNSYS) that includes plant performance and manufacturer data for the primary system components, which are comprised of pumps, chillers, cooling towers, and a thermal energy storage tank. The model is calibrated to the actual measured performance of the plant using the current control strategy as a baseline. By observing and quantifying areas for potential improvement in plant performance under conditions of high campus …

Reducing Costs In Human Assisted Speech Transcription, Justin Rovin

Master's Theses

The only official documentation of the lawmaking process at the California Legislature is unedited video recordings of committee hearings, bill texts, votes and analyses. While the bills resulting from these hearings are clear, using video recordings to understand how a bill was created is far too laborious for the average citizen. To increase public transparency, a service that provides easier access to the bill creation process was needed. In response to this need, the Digital Democracy initiative was established at Cal Poly by the Honorable Sam Blakeslee, former California State Senator and founder of the Institute for Advanced Technology and …

Synthesis And Optimization Of Emulsion Polymers, Daisy Jauregui

Master's Theses

Synthetic latex or resin is perhaps the most important component of any paint formulation. As the binder, it holds all ingredients in a paint together and is responsible for film formation. Various latexes are used in industry though acrylic resins have shown to impart superior paint properties.This project is concerned with the synthesis of an acrylic latex. Various emulsion polymerization processes were used including semi-batch, starved-feed, and in-situ seeded in the attempt to produce a stable latex that can be used in a broader study concerning the syneresis and rheology mechanisms of latex/thickener systems. In addition, this project investigates the …

Coffee Queue Project, George Dimitrov Gargov

Master's Theses

In this paper, a computer vision system for counting people standing in line is presented. In this application, common techniques such as Adaptive Background Subtraction (ABS), blob tracking with Kalman filter, and occlusion resistive techniques are used to detect and track people. Additionally, a novel method using Dual Adaptive Background Subtractors (DABS) is implemented for dynamically determining the line region in a real-world crowded scene, and also as an alternative target acquisition to regular ABS. The DABS technique acts as a temporal bandpass filter for motion, helping identify people standing in line while in the presence of other moving people. …

Seasonal And Dilution Rate Impacts On Nannochloropsis Oceanica Productivity In Algae Raceway Ponds, Garrett Dameron Murawsky

Master's Theses

Biomass growth of the alga Nannochloropsis oceanica, cultivated outdoors in six pilot-scale raceway ponds, was monitored over the course of 1.5 years, at two different dilution regimes each season, to establish the effects on algal biomass productivity and concentration of dilution rate, pond water temperature, and solar radiation. The 4.5-m² ponds were located in a mild, mid-latitude, coastal region (central California). Experimental conditions were operated in duplicates or triplicates with a consistent artificial seawater medium, pond depth, pH range, paddle wheel mixing speed, and replete nutrient conditions for the duration of the study. Two cultivation regimes were used …

Out-Of-Loop Compensation Method For Op-Amps Driving Heavy Capacitive Loads, Shubham Gandhi

Master's Theses

It is well known that real op-amps do not share most of the desirable characteristics of an ideal one, particularly those of gain and output impedance. When presented with a capacitive load, such as a MOSFET or ADC, feedback in an op-amp circuit can quickly become unstable. This thesis studies and characterizes an op-amp’s output impedance and how its interaction with this type of load creates a parasitic pole which leads to instability. Applying ideas from feedback control theory, a model for studying the problem is developed from which a generalized method for compensating the undesirable circumstance is formulated.

Even …

Design And Analysis Of A Lift Assist Walker, Deep P. Shah

Master's Theses

Walkers provided stability to the elderly but cannot assist a person from sitting to standing. The objective of this project is to present the design and analysis of a lift assist walker. This report discusses the design and analysis of a collapsible lift assist walker capable of lifting a patient up to 250 lbs. from seated to standing in under 10 seconds. The designed walker utilized a two stage scissor mechanism with a gas spring assisted embedded linear actuator.

Effect Of Low Velocity Impact On The Vibrational Behavior Of A Composite Wing, Richard M. De Luna

Master's Theses

Impact strength is one of the most important structural properties for a designer to consider, but it is often the most difficult to quantify or measure. A major concern for composite structures in the field is the effect of foreign objects striking composites because the damage is often undetectable by visual inspection. The objective for this study was to determine the effectiveness of using dynamic testing to identify the existence of damage in a small scale composite wing design. Four different impact locations were tested with three specimens per location for a total of 12 wings manufactured. The different impact …

Fluid Flow Characterization In Rapid Prototyped Common Iliac Artery Aneurysm Molds, Daniel Cole Greinke

Master's Theses

The goal of this project was to determine whether i) fused deposition modeling could be employed to manufacture molds for vascular constructs, ii) whether vascular constructs could be created from these molds, and iii) to verify practical equivalence between observed fluid velocities. Dye tracking was to be employed to characterize fluid velocity profiles through the in vitro vascular constructs, including a half-vessel model and a full vessel model of an iliac artery aneurysm. A PDMS half-vessel construct was manufactured, and the movement of dye through the construct was tracked by a cellphone camera. Thresholds were applied to each video in …

Toward High Performance Nanocarbon Fibers, Michaela R. Pfau

Master's Theses

High performance carbon fibers (CFs) have been a commercially available since their commercial boom in the 1970s, and are generally produced via carbonization of poly (acrylonitrile) (PAN). More recently, carbon nanomaterials like graphene and carbon nanotubes (CNTs) have been discovered and have shown excellent mechanical, thermal, and electrical properties due to their sp² carbon repeating structure. Graphene and CNTs can both be organized into macroscopic fibers using a number of different techniques, resulting in fibers with promising mechanical performance that can be readily multifunctionalized. In some cases, the two materials have been combined, and the resulting hybrid fibers have …

Peering In: Improving Existing Buildings With Colorful Increments, Daire Heneghan

Master's Theses

Existing office buildings’ embodied energy, history and culture offer something a newly constructed building cannot. On the other hand, new office buildings’ adoption of new technologies and building philosophies offer a range of sustainable efficiencies previously unavailable. Combining these efficiencies with elements that embrace human diversity and well- being offer the opportunity to not only mend our existing buildings’ deteriorating physical bodies but aid in creating workplaces that promote good physical and mental health.

This project provides recommendation on how an existing high-rise commercial building can incorporate a number of incremental improvements that continually evolve to meet rapidly changing market …

A Simulation Model For Decision Support In Business Continuity Planning, Marissa Anne Mosunich

Master's Theses

Enterprises with a global supply network are at risk of lost revenue as a result of disruptive disasters at supplier locations. Various strategies exist for addressing this risk, and a variety of types of research has been done regarding the identification, assessment and response to the risk of disruption in a supply chain network.

This thesis establishes a decision model to support Business Continuity Planning at the first-tier supplier level. The decision model incorporates discrete-event simulation of supply chain networks (through Simio software), Monte Carlo simulation, and risk index optimization. After modeling disruption vulnerability in a supply chain network, costs …

Towards Improved Estimates Of Upper Ocean Energetics, Alexander Grant Wineteer

Master's Theses

The energy exchanged between the atmosphere and the ocean is an important parameter in understanding the Earth’s climate. One way of quantifying this energy exchange is through the use of “wind work,” or the work done on the ocean by the wind. Since wind work is calculated according to the interaction between ocean surface currents and surface wind stress, a number of surface current decompositions can be used to decompose wind work calculations. In this research, geostrophic, ageostrophic, Ekman, and total current decompositions are all used to calculate wind work. Geostrophic currents are formed by the balance of surface pressure …