Engineering Commons^™

Development Of Cal Poly's Shock Table, Christopher D. Risner

Master's Theses

Shock is one of the environmental tests that a spacecraft must pass before being cleared for launch. Shock testing poses a challenging data acquisition issue and careful selection of equipment is crucial to creating a successful shock test facility. Cal Poly’s CubeSat programs can currently perform all environmental testing other than shock themselves, so a quality shock table would be useful. Previous groups of students had developed a shock table, and this paper details the improvement and characterization of that shock table’s behavior. Several adjustable parameters were tested and documented to discover trends in the shock table’s response to an …

Quantifying Parkinson's Disease Symptoms Using Mobile Devices, Charles R. Aylward

Master's Theses

Current assessments for evaluating the progression of Parkinson’s Disease are largely qualitative and based on small sets of data obtained from occasional doctor-patient interactions. There is a clinical need to improve the techniques used for mitigating common Parkinson’s Disease symptoms. Available data sets for researching the disease are minimal, hindering advancement toward understanding the underlying causes and effectiveness of treatment and therapies. Mobile devices present an opportunity to continuously monitor Parkinson’s Disease patients and collect important information regarding the severity of symptoms. The evolution of digital technology has opened doors for clinical research to extend beyond the clinic by incorporating …

Nanoindentation Techniques For The Evaluation Of Silicon Nitride Thin Films, Weston T. Mangin

Master's Theses

Silicon nitride thin films are of interest in the biomedical engineering field due to their biocompatibility and favorable tribological properties. Evaluation and understanding of the properties of these films under diverse loading and failure conditions is a necessary prerequisite to their use in biomedical devices. Three wafers of silicon nitride-coated silicon were obtained from Lawrence Livermore National Laboratory and used to create 96 samples. Samples were subjected to nanoindentation testing to evaluate the mechanical properties of the film. Samples were subjected to nanoimpact testing to compare the damage resistance of the film to separate nanoimpact types. Samples were subjected to …

Evaluation Of Efficiency Of Various Materials To Shield From Radiation In Space Using The Monte Carlo Transport Code Called Fluka, Roman Savinov

Master's Theses

The purpose of this study is to improve spacecraft shielding from radiation in space. It focuses on the evaluation of shielding efficiency of different materials. The efficiency of a shield is evaluated by the dose profile within the shield and the amount of dose absorbed by a target using the Monte Carlo transport code called FLUKA. The output of this code is validated by recreating the experiments from published papers and comparing the results. Once the FLUKA’s output is validated, the efficiency of sixteen materials, subject to SPE and GCR sources, are evaluated. The efficiency comparison is made by fixing …

Field Emissions Of (Hydro)Chlorofluorocarbons And Methane From A California Landfill, Alexander H. Sohn

Master's Theses

A comprehensive field investigation was conducted at Potrero Hills Landfill (PHL) located in Suisun City, California to quantify emissions of twelve (hydro)chlorofluorocarbons (i.e. F-gases). The specific target constituents for this study included CFC-11, CFC-12, CFC-113, CFC-114, HCFC-21, HCFC-22, HCFC-141b, HCFC-142b, HCFC-151a, HFC-134a, HFC-152a, and HFC-245fa. The majority of the F-gas emission studies have been conducted outside of the United States and very limited field landfill emission data are available in the United States. Because of historical usage of blowing agents in insulation foams including CFC-11, HCFC-142b, HFC-134a, and HFC-245fa, models reported in literature predicted high F-gas emissions from a landfill …

Encouraging Development Of Mobile Applications As A Service To The Community, Vanessa Marie Forney

Master's Theses

The convenience of mobile applications combined with the efficiency and effectiveness provided by technology has contributed to an increased interest in mobile applications. Local groups and non-profit organizations often utilize outdated, manual processes and don’t have the resources or time to look into improving these systems. For Cal Poly students and other members of the community, this means there is an opportunity to apply technical skills and school projects to address these inefficiencies. This work explores whether a better system can be developed to provide the functionality of the existing system and enhance the experience of users through technology, data …

Design And Analysis Of The Impact Diffusion Helmet Through A Finite Element Analysis Approach, Steven Paul Warnert

Master's Theses

By applying the finite element approach to the design and analysis of the impact diffusion helmet, many helmet configurations were able to be analyzed. Initially it was important to determine what design variables had an influence on the impact reducing abilities of the helmet design. The helmet was run through a series of Abaqus simulations that determined that a design with two oval shaped channels running along the length of the helmet was best. Next, these options were optimized to generate the helmet that produced the greatest impact reduction. The optimization simulations determined that a helmet that pushed the channels …

Laff-O-Tron: Laugh Prediction In Ted Talks, Andrew D. Acosta

Master's Theses

Did you hear where the thesis found its ancestors? They were in the "parent-thesis"! This joke, whether you laughed at it or not, contains a fascinating and mysterious quality: humor. Humor is something so incredibly human that if you squint, the two words can even look the same. As such, humor is not often considered something that computers can understand. But, that doesn't mean we won't try to teach it to them.

In this thesis, we propose the system Laff-O-Tron to attempt to predict when the audience of a public speech would laugh by looking only at the text of …

Inquiry Of Graphene Electronic Fabrication, John Rausch Greene

Master's Theses

Graphene electronics represent a developing field where many material properties and devices characteristics are still unknown. Researching several possible fabrication processes creates a fabrication process using resources found at Cal Poly a local industry sponsor. The project attempts to produce a graphene network in the shape of a fractal Sierpinski carpet. The fractal geometry proves that PDMS microfluidic channels produce the fine feature dimensions desired during graphene oxide deposit. Thermal reduction then reduces the graphene oxide into a purified state of graphene. Issues arise during thermal reduction because of excessive oxygen content in the furnace. The excess oxygen results in …

A Comparison Of Wavelet And Simplicity-Based Heart Sound And Murmur Segmentation Methods, Joshua David Korven

Master's Theses

Stethoscopes are the most commonly used medical devices for diagnosing heart conditions because they are inexpensive, noninvasive, and light enough to be carried around by a clinician. Auscultation with a stethoscope requires considerable skill and experience, but the introduction of digital stethoscopes allows for the automation of this task. Auscultation waveform segmentation, which is the process of determining the boundaries of heart sound and murmur segments, is the primary challenge in automating the diagnosis of various heart conditions. The purpose of this thesis is to improve the accuracy and efficiency of established techniques for detecting, segmenting, and classifying heart sounds …

Post-Liquefaction Residual Strength Assessment Of The Las Palmas, Chile Tailings Failure, Tristan Reyes Gebhart

Master's Theses

Assessment of post-liquefaction residual strength is needed for the development of empirically-based, predictive correlations for earthquake engineering design. Previous practice commonly assigned negligible strengths to liquefied materials for engineering analysis, producing overly-conservative designs. Increasingly available case history data, and improved analytical tools have allowed for more accurate and less overly-conservative estimation of soil residual strength, improving empirical predictive models. This study provides a new case history to the limited suite of (approximately 30) liquefaction failure case histories available for post-liquefaction in-situ strength predictive correlations.

This case history documents the Las Palmas gold mine tailings dam failure, resulting from seismic-induced liquefaction …

Identification Of Agricultural Land Use In California Through Remote Sensing, Todd Allen Robinson

Master's Theses

Ground truthing actual crop types in an area can be expensive and time-consuming. The California Department of Water Resources attempts to ground truth land use in each county in California every five years. However, this is limited by budgetary constraints and often results in infrequent (more than every ten years) surveying of many counties. An accurate accounting of crops growing in a region is important for a variety of purposes including farm production estimates, groundwater and surface water modeling, evapotranspiration estimation, water planning, research applications, etc. Agricultural land use is continually changing due to development and environmental factors.

Currently, USDA …

Experimentation Of Mode I And Mode Ii Fracture Of Uni-Directional Composites And Finite Element Analysis Of Mode I Fracture Using Cohesive Contact, Joseph Daniel Garrett

Master's Theses

As the use of fiber-reinforced composites has increased over the decades, so has the need to understand the complexity of their failure mechanisms as engineers seek to improve the damage tolerance of composite laminated structures. One of the most prevalent and limiting mode of failure within composite laminates is delamination, since it not only reduces a structures stiffness and strength, but can be very difficult to detect without the use of special non-destructive equipment. Industry testing organizations have utilized several fracture tests in order to characterize the fracture toughness of composite materials under different loading conditions. For this research, ASTM …

Scaled Synthetic Aperture Rader Development, Jason Garvey Schray

Master's Theses

Several previous Cal Poly thesis projects involve synthetic aperture radar (SAR), automatic target recognition (ATR), and tracking. SAR data was either accessed from a publicly available database or generated using complex computer modeling software. The motivation for this dual thesis project is to design and construct a scaled SAR system to support Cal Poly radar projects. Ideally this is a low-cost, high resolution SAR architecture that produces raw range Doppler data for any desired target area. To that end, a scaled SAR system was successfully designed, built, and tested. The current SAR system, however, does not perform azimuthal compression and …

A 3-D Multiplex Paper-Microfluidic Platform, Mitchell Patrick Young

Master's Theses

3-D paper-based microfluidic devices (micoPADs) are small and portable devices made out of paper that offer a promising platform for diagnostic applications outside of a laboratory. These devices are easy to use, low cost, require no power source, and capable of detecting multiple targets simultaneously. The work in this thesis demonstrated the ability of a 3-D paper-microfluidic platform to simultaneously detect 5 targets. Rubber cord stock was used in conjunction with an acrylic housing unit to apply pressure along the edge of the channel. The indirect pressure application was successful in promoting vertical fluid flow between layers. Average channel development …

Risk-Based Approach To Assessment Of Advanced Technologies For Conceptual Design, Adipratnia Asmady

Master's Theses

The conceptual design phase of an aerospace system development program is typically characterized by short duration and relatively limited resources, yet design decisions are made that have critical implications on program risk. To address the more aggressive requirements, one of these decisions is the selection of advanced technologies. System developers need to assess advanced technologies early on, but are faced with uncertainties surrounding the potential net benefits. The concept introduced in this study is uncertainty characterization as a way to better understand the associated risk. A framework was developed to guide the interaction between the technology developer and the system …

Correlation Of Polymer Performance And Hansen Solubility Parameters, Daniel Jobse Mania

Master's Theses

Ready-to-use (RTU) grout is becoming more important to the finish and remodeling construction industry. Market research shows it is a fast-growing product that not only is creating its own space, but is beginning to supplant existing technology.

The original intent of this research was to investigate formulation parameters and how they affect grout performance. It was learned that particle size and oil absorption (OA) value are important filler properties that affect performance as much as adequate packing density and optimal pigment volume concentration (PVC) without going beyond critical PVC (CPVC).

Polymer architecture was also determined to be extremely important, but …

Inducing Emotional Response In Interactive Media, Keenan M. Reimer

Master's Theses

Video games, and entertainment media have been developed for many years, and eliciting emotional experiences is an integral part of that process. Producing and editing game content in order to affect desired emotional experiences can be expensive and cumbersome to developers. This paper presents a study intended to show that such experiences can be affected with simple after-the-fact audio-visual effects. As subjects of the study, participants experience three different emotional states, fear, peace, and none, over three rounds and in three different game environments. They are given a simple narrative in each environment that directs them to gather various objects. …

Material Selection And Testing For A Radiation Therapy Catheter, Philip James Wadlow

Master's Theses

Three different polymers (a high-density polymer and two other polymers) were tested for use as an x-ray catheter in a radiation therapy application. This report describes the testing of these three materials to determine which material is the best option for a long use catheter. Tests included tensile, simulated clinical life, and other tests. Some testing was performed using nitrogen and an industrial coolant. Testing revealed significant non-circularities for some catheters. With increasing pressure, the circularity of these catheters increased. The tensile tests were performed on samples with varying doses of radiation. Tensile testing showed significant decreases in ultimate tensile …

Fluid Flow Characterization And In Silico Validation In A Rapid Prototyped Aortic Arch Model, Alexandra Mariel Knauer

Master's Theses

Transcatheter aortic heart valve replacement (TAVR) is a procedure to replace a failing aortic valve and is becoming the new standard of care for patients that are not candidates for open-heart surgery [2]. However, this minimally invasive technique has shown to cause ischemic brain lesions, or “silent infarcts”, in 90% of TAVR patients, which can increase the patient’s risk for stroke by two to four times in future years [3]. Claret Medical Inc., a medical device company, has developed a cerebral protection system that filters and captures embolic debris released during endovascular procedures, such as TAVR. This thesis utilized CT …

Superalloy Metallurgy A Gleeble Study Of Environmental Fracture In Inconel 601, Alan C. Demmons

Master's Theses

At temperatures above 0.5 Tm and in aggressive atmospheres predicting alloy performance is particularly challenging. Nickel alloys used in regimes where microstructure and properties are altered dynamically present unique requirements. Exposure may alter properties with unexpected early failure. The Gleeble is a valuable tool for investigation and simulation of thermo-mechanical properties of an alloy in various regimes up to the threshold of melting. In this study, four regimes of temperature and strain rate were simulated in an argon atmosphere to both investigate and document normal and abnormal failure modes. Commercial Inconel 601 was tested in selected regimes and in two …

Complex Filters As As A Cascade Of Of Buffered Gingell Structures: Design From From Band-Stop Constraints, Samuel Robert Johnston

Master's Theses

This thesis presents an active Complex Filter implementation that that creates a transfer function with with a single real pole and a complex zero. The two-input/two-output network developed in in this thesis responds differently based upon upon the relative phase difference of of the two inputs. If a negative ninety-degree phase difference occurs between the two inputs, the filter will exhibits a bandstop response. While a positive ninety-degree phase difference exhibits a bandpass response. This topology is relatesd to to Gingell’s RC-CR polyphase topology but because of of the use of of op-amps, can be cascadedd without without suffering loading …

Regrowth Of Chlorella Sorokiniana On Recycled Media With Replenished Nutrients, William H. Spence

Master's Theses

Growth media recycling during algae cultivation is necessary to increase the efficiency and reduce the cost of biofuel production from algae feedstocks. Without recycling media, the cost of algae based biofuel production would be prohibitively high and large scale algae based biofuel production would not be economically viable. The ratio of media recycled to media wasted assumed for algae farms is generally calculated to maintain salt concentrations below growth inhibitory levels, ignoring the influence of secondary metabolites which might decrease productivity. Secondary metabolites, which include allelopathic or auto-inhibitory biological contaminants, might lead to the accumulation of growth-inhibiting compounds in recycled …

Arc Fault Circuit Interrupter Development For Residential Dc Electricity, Cassidy Alan Aarstad

Master's Theses

The following technical report describes the development and testing of an arc fault circuit interrupter (AFCI) for DC circuits operating primarily at 48 volts. We have identified an effective method for determining when arcing is occurring. Our method is primarily based on comparing the frequency spectrum of current flowing through the circuit during an arcing event to a known characteristic spectrum. Once an arc has been identified, our interrupter is capable of responding adequately to eliminate the arc. Hardware tests show the AFCI developed in this thesis responded, in all test cases, within 2 seconds of an arc fault occurrence. …

Ncma Groundwater Model Using Usgs Modflow-2005/Pest, Brian Matthew Wallace

Master's Theses

A numerical model for the NCMA aquifer complex is presented. The objective of the study is to develop a numerical groundwater model for the NCMA aquifer system to enhance the understanding of subsurface groundwater flow. Infiltration, streamflow, pumping, and return flows are implemented to characterize the aquifer complex over time. The numerical model is calibrated to municipal and monitoring well data, average monthly water balances, and hydraulic contours. Transient aquifer inflows and outflows are assessed in the results of the study and are compared to balance terms from previous studies. The 2007 Todd Engineers Study subsurface inflows and outflows generate …

Astro – A Low-Cost, Low-Power Cluster For Cpu-Gpu Hybrid Computing Using The Jetson Tk1, Sean Kai Sheen

Master's Theses

With the rising costs of large scale distributed systems many researchers have began looking at utilizing low power architectures for clusters. In this paper, we describe our Astro cluster, which consists of 46 NVIDIA Jetson TK1 nodes each equipped with an ARM Cortex A15 CPU, 192 core Kepler GPU, 2 GB of RAM, and 16 GB of flash storage. The cluster has a number of advantages when compared to conventional clusters including lower power usage, ambient cooling, shared memory between the CPU and GPU, and affordability. The cluster is built using commodity hardware and can be setup for relatively low …

The Effects Of Latency On 3d Interactive Data Visualizations, Allen Korenevsky

Master's Theses

Interactive data visualizations must respond fluidly to user input to be effective, or so we assume. In fact it is unknown exactly how fast a visualization must run to present every facet within a dataset. An engineering team with limited resources is left with intuition and estimates to determine if their application performs sufficiently well.

This thesis studies how latency affects users' comprehension of data visualizations, specifically 3D geospatial visualizations with large data sets. Subjects used a climate visualization showing temperatures spanning from the 19th to the 21st century to answer multiple choice questions. Metrics like their eye movements, time …

Design Of An Integrated Acceleration Acquisition Subsystem To Satisfy High-Speed And Low-Area Requirements For Cubesats, Ryan J. Rumsey

Master's Theses

Cal Poly San Luis Obispo’s PolySat team is designing the Multipurpose Orbital Spring Ejection System (MOSES) in order to record acceleration data during the launch of CubeSats as well as to provide GPS coordinates to locate the position of CubeSats once they are injected into orbit. This work focuses on the design and development of the acceleration data acquisition (DAQ) subsystem of MOSES. This subsystem is designed around the need for a high-speed sampling system of at least 200 kHz across four channels of data, plus low-area limitations in the MOSES form factor which is roughly half the size of …

Anex: Automated Network Exploitation Through Penetration Testing, Eric Francis Dazet

Master's Theses

Cyber attacks are a growing concern in our modern world, making security evaluation a critical venture. Penetration testing, the process of attempting to compromise a computer network with controlled tests, is a proven method of evaluating a system's security measures. However, penetration tests, and preventive security analysis in general, require considerable investments in money, time, and labor, which can cause them to be overlooked. Alternatively, automated penetration testing programs are used to conduct a security evaluation with less user effort, lower cost, and in a shorter period of time than manual penetration tests. The trade-off is that automated penetration testing …

Graph-Based Data Visualization In Virtual Reality: A Comparison Of User Experiences, Paul Andrew Sullivan

Master's Theses

Virtual reality is currently in the spotlight, attracting intense scrutiny by the press, technology companies, and consumers. After twenty years of dormancy, the technology has experienced a renaissance following advancements in both hardware and software. Most of these developments, and thus press attention, have been centered on entertainment. However, if the technology is going to continue to grow, it must be useful in a wide variety of situations. This paper explores the effectiveness of visualizing data in virtual reality in comparison to traditional presentations.

In this thesis, we present an approach to displaying data in a virtual reality environment. We …