Engineering Commons^™

Hip And Knee Biomechanics For Transtibial Amputees In Gait, Cycling, And Elliptical Training, Greg Orekhov

Master's Theses

Transtibial amputees are at increased risk of contralateral hip and knee joint osteoarthritis, likely due to abnormal biomechanics. Biomechanical challenges exist for transtibial amputees in gait and cycling; particularly, asymmetry in ground/pedal reaction forces and joint kinetics is well documented and state-of-the-art passive and powered prostheses do not fully restore natural biomechanics. Elliptical training has not been studied as a potential exercise for rehabilitation, nor have any studies been published that compare joint kinematics and kinetics and ground/pedal reaction forces for the same group of transtibial amputees in gait, cycling, and elliptical training. The hypothesis was that hip and knee …

Population Curation In Swarms: Predicting Top Performers, Ryan W. Heller

Master's Theses

In recent years, new Artificial Intelligence technologies have mimicked examples of collective intelligence occurring in the natural world including flocks of birds, schools of fish, and swarms of bees. One company in particular, Unanimous AI, built a platform (UNU Swarm) that enables a group of humans to make decisions as a single mind by forming a real-time closed-loop feedback system for individuals. This platform has proven the ability to amplify the predictive ability of groups of humans in realms including sports, medicine, politics, finance, and entertainment. Previous research has demonstrated it is possible to further enhance knowledge accumulation within a …

Ridership Ramp-Up For Fixed-Guideway Transit Projects: An Evaluation Of Initial Ridership Variation, Jill Elizabeth Shinn

Master's Theses

Performance-based planning and programming has increased in popularity for transit project funding in recent years. This methodology focuses on quantitative performance measures to inform decision making. For transit projects, projections or observed ridership is the most commonly used performance measure to evaluate project benefits. Conventional wisdom within the transit industry suggests that measuring the performance of a transit project immediately after project opening may not capture all the project’s benefits, since it takes time for a project to realize its short-term ridership potential, a process commonly referred to as ridership ramp-up. While this idea is both intuitive and appealing, especially …

Increasing Algal Productivity And Treatment Potential In Raceways Fed Clarified Municipal Wastewater, Christopher D. Pittner

Master's Theses

Two sets of triplicate pilot algal raceway ponds (1000-L, 0.30-m deep, paddle wheel mixed) were operated for 14 months at a California wastewater treatment plant to treat wastewater and generate algal-bacterial biomass as biofuel feedstock. Two experiments were run to determine the effect on biomass productivity of (1) hydraulic residence time (HRT: 2, 3, 4, or 4.5 days) and (2) feeding schedule (18 small pulses during 8 AM-4 PM [diurnal] versus 20 large pulses during 4 AM-12 AM [diel]). The target productivity was at least 20 g volatile suspended solids per m2 of pond per day. Additional output variables were …

A Novel All Wheel Drive Torque Vectoring Control System Applied To Four Wheel Independent Drive Electric Motor Vehicles Utilizing Super Twisting And Linear Quadratic Regulator Methods, Kenneth Daniel Schmutz

Master's Theses

This thesis contains the design and simulation test results for the implementation of a new all-wheel drive (AWD) torque vectoring (TV) control system. A separate algorithm using standard control methods is included in this study for a comparison. The proposed controller was designed to be applied to an AWD independent drive electric vehicle, however the main concepts can be re-purposed for other vehicle drive train configurations. The purpose of the control system is to assist the driver in achieving a desired vehicle trajectory whilst also maintaining stability and control of the vehicle. This is accomplished by measuring various real time …

Bi-Stability In The Wakes Of Platooning Ahmed Bodies, Daniel M. Stalters

Master's Theses

Autonomous heavy vehicles will enable the promise of decreased energy consumption through the ability to platoon in closer formation than is currently safe or legal. It is therefore increasingly important to understand the complex and dynamic wake interactions between vehicles operating in close proximity for aerodynamic gains. In recent years, a growing body of research has documented a bi-stable, shifting wake generated behind the Ahmed reference bluff body. At the same time, studies of platooning Ahmed bodies have focused on changes to the body forces and moments at different following distances or lateral offsets, typically based around time-averaged measurements or …

Analysis Of Student-Athletes And Summer Internship Experiences Int He Construction Management Department, Amanda R. Sandoval

Construction Management

Summer internships are a valuable way for implementing practical knowledge in the construction industry. Students can apply what they have learned during the school year and visualize the reality of how construction is managed. This project will research what student-athletes typically invest their time in over summer and the construction company’s connection to the student-athlete department. The analysis will identify if there is a need to propose a program that can improve the relationship between the construction management and student-athlete departments. Two surveys were conducted to collect information about student-athletes summer activity history and their perspective of internship experience, as …

Measuring Liquefied Residual Strength Using Full-Scale Shake Table Cyclic Simple Shear Tests, Taylor R. Honnette

Master's Theses

This research consists of full-scale cyclic shake table tests to investigate liquefied residual strength of #2/16 Monterey Sand. A simple shear testing apparatus was mounted to a full-scale one-dimensional shake table to mimic a confined layer of saturated sand subjected to strong ground motions. Testing was performed at the Parson’s Geotechnical and Earthquake Laboratory at California Polytechnic State University, San Luis Obispo. T-bar penetrometer pullout tests were used to measure residual strength of the liquefied soil during cyclic testing. Cone Penetration Testing (CPT) was performed on the soil specimen throughout testing to relate the laboratory specimen to field index test …

Using Net Groundwater Extractions For Farm Level Groundwater Sustainability Monitoring, Daniel J. Howes, Morgan Whinery, Eric Limas, Dan Vink

BioResource and Agricultural Engineering

The Cal Poly Irrigation Training and Research Center (ITRC) has developed a method for computing net groundwater extraction and recharge at the farm level for district management and regulation of sustainable/safe yields. This method is called Net To/From Groundwater (NTFGW). Net groundwater extraction is preferred for assessing sustainable yield in unconfined aquifer systems over direct metering of gross groundwater pumping. A recent pilot project with the Lower Tule River and Pixley Irrigation Districts’ Groundwater Sustainability Agencies (GSAs) compared actual metered groundwater pumping, surface deliveries, and evapotranspiration to the NTFGW outputs on 19 farms within the GSAs over a 3-year period …

Techedsat 7 And 8-Nasa Missions For Earth Observation, Andrew Pham

STAR Program Research Presentations

Big results can come from small satellites, and Technology Educational Satellite 8 or TES-8 is the latest small satellite in the TechEdSat series from NASA Ames Research Center. TechEdSat is a collaborative program, in which advanced university students have a chance to work directly with researchers on NASA Space Projects. Thanks to the assistance of students from several universities around the country every year, TechEdSat has helped NASA develop Nano-satellite technologies and evaluate new ideas for future spacecraft. TES-8 is the eighth satellite of the continuing TechEdSat series. On December 01, 2018 TES-8 followed a Commercial Resupply Service mission to …

An Assessment Of The Greatest Impacts On Distribution Uniformity For Drip And Micro Irrigation, Brooke Ashley Worden

Master's Theses

Using the Cal Poly Irrigation Training and Research Centers (ITRC) drip/micro evaluation program, global, or system, DU_lq is computed by combining the component DU_lq values of: pressure variation, uneven spacing between emitters, unequal drainage and “other” causes. “Other” causes include plugging, wear and manufacturing coefficient. The program also computes what percentage of the non-uniformity is due to each component. Burt (2004) showed that over 95% of the non-uniformity is due to “Other” causes and pressure differences. This thesis looks at what specifically in those components is driving the non-uniformity by analyzing various equipment and field practices and their …

Microfluidic Electrical Impedance Spectroscopy, John J. Foley

Master's Theses

The goal of this study is to design and manufacture a microfluidic device capable of measuring changes in impedance valuesof microfluidic cell cultures. Tocharacterize this, an interdigitated array of electrodes was patterned over glass, where it was then bonded to a series of fluidic networks created in PDMS via soft lithography. The device measured ethanol impedance initially to show that values remain consistent over time. Impedance values of water and 1% wt. saltwater were compared to show that the device is able to detect changes in impedance, with up to a 60% reduction in electrical impedance in saltwater. Cells were …

In Vitro Growth Of Osteoblasts On Poly Lactic-Co-Glycolic Acid Scaffolds Created Via Gas Foaming, Matthew James Thomas

Master's Theses

This study analyzed the feasibility of using gas foaming to create Poly Lactic-co-Glycolic Acid (PLGA) scaffolds for use as a substrate in bone tissue engineering and set out to determine whether the presence of osteoblasts on these scaffolds enhanced their material stiffness. The process of bone formation involves osteoblasts depositing extracellular matrix and calcifying this matrix with calcium phosphate crystals (Hasegawa et al., 2017) and pits between 30-40μm in diameter on tissue engineering scaffold surfaces have been shown to best promote osteogenic activity in the presence of bone-forming cells (Halai et al., 2014).The scaffolds were determined to contain pits within …

Subject-Specific Finite Element Predictions Of Knee Cartilage Pressure And Investigation Of Cartilage Material Models, Michael G. Rumery

Master's Theses

An estimated 27 million Americans suffer from osteoarthritis (OA). Symptomatic OA is often treated with total knee replacement, a procedure which is expected to increase in number by 673% from 2005 to 2030, and costs to perform total knee replacement surgeries exceeded $11 billion in 2005. Subject-specific modeling and finite element (FE) predictions are state-of-the-art computational methods for anatomically accurate predictions of joint tissue loads in surgical-planning and rehabilitation. Knee joint FE models have been used to predict in-vivo joint kinematics, loads, stresses and strains, and joint contact area and pressure. Abnormal cartilage contact pressure is considered a risk factor …

Relationship Between Time-Constants And 3db Cutoff Of High-Order Damped Lti Systems, Vladimir I. Prodanov, Katherina Prodanov

Electrical Engineering

This paper deals with linear time-invariant (LTI) systems and examines the link between the 3dB cutoff and time-constants. It shows that the cutoff frequency of a low-pass damped network can be estimated from the reciprocal of a p-norm calculated from the system's time-constants. Furthermore, to achieve good accuracy the p factor must have a fractional value, for example, p=1.7. Two formulas are derived, and their performance evaluated using Monte Carlo simulations which reveal a sub-3% error for most cases.

Experimental Study And Modeling Of The GM-I Dependence Of Long-Channel Mosfets, Michael Cheng, Vladimir I. Prodanov

Electrical Engineering

This paper describes an experimental study and modeling of the current-transconductance dependence of the ALD1106 and ALD1107 arrays. The study tests the hypothesis that the I-g _m dependence of these 7.8 μm MOSFETs conforms to the Advanced Compact Model (ACM). Results from performed measurements, however, do not support this expectation. Despite the relatively large length, both ALD1106 and ALD1107 show sufficiently pronounced `short-channel' effects to render the ACM inadequate. As a byproduct of this effort, we confirmed the modified ACM equation. With an m factor of approximately 0.6, it captures the I-g _m dependence quite well. The paper also introduces …

Inverse Dynamic Analysis Of Acl Reconstructed Knee Joint Biomechanics During Gait And Cycling Using Opensim, Megan V. Pottinger

Master's Theses

ACL (anterior cruciate ligament) injuries of the knee joint alter biomechanics and may cause abnormal loading conditions that place patients at a higher risk of developing osteoarthritis (OA). There are multiple types of ACL reconstruction (ACLR), but all types aim to restore anterior tibial translation and internal tibial rotation following surgery. Analyzing knee joint contact loads provide insight into the loading conditions following ACLR that may contribute to the long-term development of OA. Ten ACLR subjects, who underwent the same reconstruction, performed gait and cycling experiments while kinematic and kinetic data were collected. Inverse dynamic analyses were performed on processed …

Design And Analysis Of A Parabolic Trough Solar Concentrator, George N. Skouras

Master's Theses

A prototype solar desalination system (SODESAL) with a parabolic-trough solar concentrator (PTSC) and evacuated tube was designed and analyzed to determine the solar thermal capabilities for small-scale distillation and energy generation. A proof-of-concept study verified that distillation is possible with the system as designed, however a rupture occurred in the copper heat-pipe heat exchanger due to overheating. The internal temperatures of an aluminum heat transfer fin were measured inside an evacuated tube typically used in solar water heater systems to understand the lateral heat distribution and identify possible causes of the rupture. Solar radiation was measured for both the summer …

Pnnl Dark Matter Bubble Chamber, Ryan Robinson

STAR Program Research Presentations

The Pacific Northwest National Laboratory (PNNL) prototype bubble chamber is intended to address issues encountered with the current PICO dark matter search detectors and improve the functionality of future experimental designs. The PNNL bubble chamber accomplishes this with a simplified interface between the hydraulic pressure controls and the target vessel and altering the standard chamber design such that it can be easily exchanged and replaced with vessels of various sizes and materials for testing purposes. The chamber itself is a glass vessel which houses perfluorobutane and holds the target fluid above room temperature and atmospheric pressure. The target fluid becomes …

Asic Design Of Rf Energy Harvester Using 0.13um Cmos Technology, Jainish K. Zaveri

Master's Theses

Recent advances in wireless sensor nodes, data acquisition devices, wearable and implantable medical devices have paved way for low power (sub 50uW) devices. These devices generally use small solid state or thin film batteries for power supply which need replacement or need to be removed for charging. RF energy harvesting technology can be used to charge these batteries without the need to remove the battery from the device, thus providing a sustainable power supply. In other cases, a battery can become unnecessary altogether. This enables us to deploy wireless network nodes in places where regular physical access to the nodes …

Iris Biometric Identification Using Artificial Neural Networks, Kevin Joseph Haskett

Master's Theses

A biometric method is a more secure way of personal identification than passwords. This thesis examines the iris as a personal identifier with the use of neural networks as the classifier. A comparison of different feature extraction methods that include the Fourier transform, discrete cosine transform, the eigen analysis method, and the wavelet transform, is performed. The robustness of each method, with respect to distortion and noise, is also studied.

The Development And Validation Of Sinatra: A Three-Dimensional Direct Simulation Monte Carlo (Dsmc) Code Written In Object-Oriented C++ And Performed On Cartesian Grids, David Matthew Galvez

Master's Theses

The field of Computational Fluid Dynamics (CFD) primarily involves the approximation of the Navier-Stokes equations. However, these equations are only valid when the flow is considered continuous such that molecular interactions are abundant and predictable. The Knudsen number, $Kn$, which is defined as the ratio of the flow's mean free path, $\lambda$, to some characteristic length, $L$, quantifies the continuity of any flow, and when this parameter is large enough, alternative methods must be employed to simulate gases. The Direct Simulation Monte Carlo (DSMC) method is one which simulates rarefied gas flows by directly simulating the particles that compose the …

Water Hammer Protection For Pumped Turnouts On Aging Pipelines, Charles M. Burt, Zachary C. Markow

BioResource and Agricultural Engineering

Water hammer in an irrigation district pipeline is typically caused by sudden changes in turnout flow rates. A sudden shutoff of a booster pump, or a rapid closure of a turnout valve, can potentially cause surge damage. The problem occurs if the pressure exceeds the pressure rating of the pipeline. As pipes age, their pressure rating typically declines. This report describes three different solutions that utilize a combination of these techniques/devices to provide district pipeline protection from water hammer.

The Effect Of Destoning And Enzymatic Pretreatments On The Biofuel Production From Olive Cake, Patrick Tai

Master's Theses

More than 16,000 tons of olive cake was produced in the United States in 2017. Olive cake is a by-product of olive oil extraction, which has limited animal feed potential, and poses an environmental threat when landfilled due to its high organic load and polyphenol content. This residue has potential for biofuel (bioethanol and biomethane) production because it is rich in polysaccharides such as pectin, hemicellulose, and cellulose. Yet, olive cake contains olive stones that can impede its conversion to biofuel. Therefore, two methods of destoning, centrifugation and screening by horizontal screw press, were first compared. Both methods removed an …

Logistics And Funding Plan For The Simpson Strong-Tie Lab Crane, Arya Ghourchian

Construction Management

In the recent years, there has been interests regarding an overhead crane to be erected inside of Cal Poly Simpson Strong-Tie Lab (Building 187). This under-running single girder crane system will be used for construction classes and to lift heavy equipment. The installment of this 2-ton indoor crane will be crucial to provide modular pieces, for whom that lost their homes due to the California fires. Additionally, there has been previous senior project researches; reference SST Preconstruction Services and Structural Analysis of SST Lab. I am in charge of collecting information regarding: Bid Estimate Comparison, Advertisement Strategy, Permit Compliance. This …

Alumni Grassroots Leadership Enables Sponsored Course Development, Vladimir I. Prodanov, John Greene

Electrical Engineering

This paper presents a lab-centric course development where alumni, employed by an IAB member company, play a pivotal role. Recently the lead author of this paper qualified for a sabbatical leave and the college enthusiastically approved the proposal (a 400-level elective in networked sensors). He considered two class structures: lecture-only and lecture-lab. While lecture-lab is the desired mode of instruction, the development of such a course would take at least 2 quarters. Since extended sabbaticals are only partly funded by the university the creation of a lecture-lab course hinged on the availability of a sponsor. Simultaneously an alumnus, now with …

Preparation And Characterization Of Eva/Cort Microparticles For Rattlesnake Endocrinology Studies, Alexander C. Pauer

Materials Engineering

No abstract provided.

In Situ Sem Solidification Study Of Ga And Egain: A Characterization Technique For Monitoring The Microstructural Evolution Of Liquid Metals, Jeremy Geovann Del Aguila

Materials Engineering

Scanning electron microscopy (SEM) video recording is used to characterize the solidification of small volumes of 99.999% pure gallium (Ga) and eutectic gallium-indium (eGaIn) under a high vacuum environment. Specimen are superheated to 55℃ using a hot plate, cast into spherical droplets, and cooled in situ by means of a Peltier cooling stage. Special attention is given to the preparation of the specimen prior to viewing because of gallium and its alloys’ nature to form an oxide layer when melted and air cooled. The oxide acts as a skin that inhibits the observation of microstructural features during solidification. Heated samples …

Genetic Algorithm Amplifier Biasing System (Gaabs): Genetic Algorithm For Biasing On Differential Analog Amplifiers, Sean Whalen

Computer Engineering

Genetic Algorithm Amplifier Biasing System (GAABS) - Senior Project Analysis

Summary of Functional Requirements

This project integrates LTSpice with a python script that runs a genetic algorithm to bias a differential amplifier. The system biases the amplifier with 2 different voltages, the base voltage for the PNP BJTs of the active loads and a voltage controlling the current of the current sink. The project runs via a python script, gets data from LTSpice’s command line call, and iteratively runs until the system is biased to achieve the greatest gain on an arbitrary input voltage.

Primary Constraints

Some of the main …

An Evaluation Of Ultrasonic Shot Peening And Abrasive Flow Machining As Surface Finishing Processes For Selective Laser Melted 316l, Rhys Gilmore

Master's Theses

Additive Manufacturing, and specifically powder bed fusion processes, have advanced rapidly in recent years. Selective Laser Melting in particular has been adopted in a variety of industries from biomedical to aerospace because of its capability to produce complex components with numerous alloys, including stainless steels, nickel superalloys, and titanium alloys. Post-processing is required to treat or solve metallurgical issues such as porosity, residual stresses, and surface roughness. Because of the geometric complexity of SLM produced parts, the reduction of surface roughness with conventional processing has proven especially challenging. In this Thesis, two processes, abrasive flow machining and ultrasonic shot peening, …