Engineering Commons^™

Physics-Based And Behavioral Models For Fuel Cells, Charles Chima Anyim

Theses and Dissertations

In recent times there has been renewed interest in fuel cells for electricity production, especially for transportation applications. Fuel cells are attractive because the electricity production process from chemical energy does not cause pollution, and no carbon emissions occur. In this work, we will focus on Proton Exchange Membrane (PEM) fuel cells that use hydrogen and oxygen to generate electricity, producing only electricity, heat and water. If hydrogen can be produced in a green, non-polluting way, fuel cells can truly be an environmentally benign energy source.

In this work, we will look at the modeling of a fuel cell system. …

Novel Structures And Thin Film Techniques For Reconfigurable Rf Technologies With Improved Signal Integrity, Jinqun Ge

Theses and Dissertations

Over the past several decades, wireless communications have been tremendously developed with multiple frequency bands, standards, and functions to provide more convenient communication services. Nowadays, commercial wireless devices, especially customer premises equipment, are required for smaller size, higher integration, and higher data rates to meet the ever-increasing demands of communications. The transceiver front ends inside these devices need to provide high-speed and high-quality communication services without a substantial increase in cost and size. Hence, the primary objective of this research is to develop a few miniaturized, multifunctional, and reconfigurable RF technologies and to provide several signal integrity and heat dissipation …

Utilizing Deep Learning Methods In The Identification And Synthesis Of Gene Regulations, Jiandong Wang

Theses and Dissertations

Gene expression is the fundamental differentiation and development process of life. Although all cells in an organism have essentially the same DNA, cell types and activities vary due to changes in gene expression. Gene expression can be influenced by many gene regulations. RNA editing contributes to the variety of RNA and proteins by allowing single nucleotide substitution. Reverse transcription can alter the expression status of genes by inducing genetic diversity and polymorphism via novel insertions, deletions, and recombination events. Gene regulation is critical to normal development because it enables cells to respond rapidly to environmental changes. However, identifying gene regulations …

Characterization Of The Spatial And Temporal Dynamics Of Floodplain Surface-Water Circulation, Shailesh Cyriel Van Der Steeg

Theses and Dissertations

Floodplains are spatially complex landscapes with a variety of surface features and landforms. These low-relief, low-gradient landscapes may contain extensive networks of well-defined channels and topographically connected depressions, and in some cases, the channels originate as cuts across levees or banks of the main river, referred to as through-bank channels. Corresponding complex patterns of inundation and flow have been detected through remote sensing and in field observations. The complex floodplain flows in response to the passing of flood waves is, however, poorly quantified. This work aims to increase fundamental understanding of floodplain flows and to highlight controls on floodplain wetting, …

Speckle Development And Application In Uav-Based Digital Image Correlation For Transportation Infrastructure Monitoring And Assessment, Taylor Wyatt

Theses and Dissertations

A critical aspect of civil infrastructure is structural health monitoring, of which digital image correlation (DIC) has been proven to be an effective and appropriate method. There is sufficient literature on the use of stationary DIC, but an unexplored aspect is DIC-equipped unmanned aircraft systems. It has been verified in University of South Carolina labs but has not been proved in a field environment. One of the challenges of field implementation is large scale speckle application. This work focusses on identifying and addressing challenges in bringing UAV-DIC technology from the lab to the field. This includes the development of optimized …

Multidimensional Transport-Coupled Numerical Investigation Of Non-Premixed Low-Temperature Flame In Atmospheric And High-Pressure Systems, Sudipta Saha

Theses and Dissertations

Gas-phase chemical reactions coupled with multidimensional fluid flow and heat and mass transport are found in various applications, i.e., from conventional engine applications to novel combustion techniques. With the goal of understanding such complex coupling in reacting flow systems, this dissertation work focuses on developing multi-physics simulation frameworks to investigate the effect of multidimensional transport on flame dynamics. This study primarily focuses on the modeling and simulation of low temperature flame formation in i) a canonical experimental setting with counterflow burners and ii) a supercritical water medium (i.e., hydrothermal flame).

In the first part of the dissertation, simulations of the …

Development And The Use Of A New Kinetically Limited Linear Driving Force Model For Diffusion-Based Adsorptive Separations, Sulaimon Adedayo Adegunju

Theses and Dissertations

A new kinetically limited linear driving force (KLLDF) model, in terms of a modified extended Langmuir (EL) isotherm, was developed. This KLLDF model augments the equilibrium driving force in the linear driving force (LDF) model in such a way that the equilibrium loading of each component in the LDF model depends on the actual, kinetically limited, loading of the other components in a gas mixture, not their partial pressures. In contrast, the LDF model assumes the presence of a slower diffusing adsorbate in a gas mixture affects the equilibrium of a faster diffusing adsorbate in a pore structure via its …

Design Of A Tvsa Cycle For Co2 Removal From Spacecraft Cabins Using A Structured Adsorbent, Pravin Bosco Charles Antony Amalraj

Theses and Dissertations

Pressure Swing Adsorption (PSA) and Temperature Swing Adsorption (TSA) are some of the most used cyclic adsorption technologies that is used for separating gas components from its mixture. Carbon Dioxide Removal Assembly (CDRA) in the International Space Station (ISS) facilitates the continuous removal of CO2 by the cyclic adsorption process. The use of structured adsorbents has drawn attention due its several advantages over traditional beaded adsorbents. This work evaluates the role of different design variables on the effective thermal conductivity of a structured adsorbent bed for its possible application in a temperature swing adsorption (TVSA) process for space applications. The …

Development Of A Metal Droplet Generator For Studying Impact Dynamics, Xitong Xu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Metal droplet-based 3D printing is a popular technique used for creating complex structures and multi-material components. However, accuracy is a significant challenge in this process due to complex thermal and dynamic behaviors that can negatively affect the final workpiece. To improve accuracy, the interactions between droplet impact dynamics and the deposition process of the droplets must be understood and ultimately controlled. In this thesis, I describe the optimization and implementation of an experimental setup for generating droplets of tin and for studying their impact dynamics. In particular, this thesis explains how an existing preliminary droplet generator was modified to produce …

Flame Assisted Additive Manufacturing For The Synthesis Of High-Temperature Materials, Chang Xia

McKelvey School of Engineering Graduate Student Theses & Dissertations

In recent years, environmental protection has taken center stage, prompting industries to develop clean, efficient, and cost-effective energy and energy-related technologies. However, achieving these goals remains challenging in many fields.

Additive manufacturing, an emerging technology for producing high-temperature materials non-traditionally, offers a promising solution. This method enables 3D printing of materials that can withstand high-temperature environments, which are crucial in nuclear reactions and aerospace applications. Additive manufacturing offers several key advantages, including design flexibility and the ability to create complex geometries during the manufacturing process.

In recent years, additive manufacturing has emerged as a novel technique for producing high-temperature materials, …

The Photochemical Evolution Of Polycyclic Aromatic Hydrocarbons And Nontronite Clay On Early Earth And Mars, Nina Kopacz, Maria Angela Corazzi, Giovanni Poggiali, Ayla Von Essen, Vincent Kofman, Teresa Fornaro, Hugo Van Ingen, Eloi Camprubi, Helen E. King, John Brucato, Inge Loes Ten Kate

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The photochemical evolution of polycyclic aromatic hydrocarbons (PAHs), an abundant form of meteoritic organic carbon, is of great interest to early Earth and Mars origin-of-life studies and current organic molecule detection efforts on Mars. Fe-rich clay environments were abundant on early Earth and Mars, and may have played a role in prebiotic chemistry, catalyzing the breakdown of PAHs and freeing up carbon for subsequent chemical complexification. Current Mars is abundant in clay-rich environments, which are most promising for harboring organic molecules and have comprised the main studied features by the Curiosity rover in search of them. In this work …

Computationally Efficient Analysis And Optimization Of Induction Motors, Hossein Nejadi Koti

Dissertations (1934 -)

The goal of this dissertation is to establish computationally efficient large-scale design optimization procedures for induction motors that are not only computationally efficient, but also do not sacrifice the accuracy of the results. To achieve this goal, the topic of the lengthy numerical transient response of Time-Stepping Finite Element Analysis (TS-FEA) of induction motors was investigated. This is because this lengthy transient affects the computational efficiency aspect of the optimization process. The effect of different parameters on the numerical transient response phenomenon were studied, and two different techniques for mitigation of this numerical transient were evaluated. The superior one amongst …

Evaluating The Impact Of Land Use Changes, Drivers Of Tmdl Development, And Green Infrastructure On Stream Impairments, Charitha Jayasri Gunawardana

Dissertations (1934 -)

Despite the water quality improvements and regulatory advancements over the last 50 years since the enactment of the Clean Water Act, water bodies within the United States are still impaired for a broad range of contaminants from non-point source pollution. Improving watershed management approaches to meet this challenge will require a greater understanding of (1) how changes within a watershed, such as changing land use, impact stream water quality, (2) what influence socioeconomic, spatial and political factors may have on the progress towards meeting water quality goals, such as those set within Total Maximum Daily Loads (TMDLs), and (3) how …

Downstream Task Self-Supervised Learning For Object Recognition And Tracking, Abubakar Siddique

Dissertations (1934 -)

This dissertation addresses three limitations of deep learning methods in image and video understanding-based machine vision applications. Firstly, although deep convolutional neural networks (CNNs) are efficient for image recognition applications such as object detection and segmentation, they perform poorly under perspective distortions. In real-world applications, the camera perspective is a common problem that we can address by annotating large amounts of data, thus limiting the applicability of the deep learning models. Secondly, the typical approach for single-camera tracking problems is to use separate motion and appearance models, which are expensive in terms of computations and training data requirements. Finally, conventional …

Probabilistic Model Development And Risk Management Strategies For Pipelines With Anomalies, Kiswendsida Jules Kere

Dissertations (1934 -)

Metal pipelines are exposed to many threats such as corrosion and cracking during their service life, which can weaken pipeline integrity and cause leaks or ruptures, leading to significant safety, economic and environmental consequences. For corrosion, many models have been developed to predict failure pressure of pipeline with an isolated defect, and only a few models consider interacting defects. On the other hand, the existing models for predicting failure pressure of pipeline with crack defects are very limited. Several model performance evaluations have shown that most of the existing models for either corrosion or cracking-like defects are conservative since they …

Design And Advanced Model Predictive Control Of Wide Bandgap Based Power Converters, Waqar Ahmed Khan

Dissertations (1934 -)

The field of power electronics (PE) is experiencing a revolution by harnessing the superior technical characteristics of wide-band gap (WBG) materials, namely Silicone Carbide (SiC) and Gallium Nitride (GaN). Semiconductor devices devised using WBG materials enable high temperature operation at reduced footprint, offer higher blocking voltages, and operate at much higher switching frequencies compared to conventional Silicon (Si) based counterpart. These characteristics are highly desirable as they allow converter designs for challenging applications such as more-electric-aircraft (MEA), electric vehicle (EV) power train, and the like. This dissertation presents designs of a WBG based power converters for a 1 MW, 1 …

Method Design For Separation Of Non-Canonical Dna Structures Via Capillary Electrophoresis, Erin V. Chen , '23

Senior Theses, Projects, and Awards

G-quadruplex DNA structures are highly relevant subjects of biochemical study, implicated in human diseases and cancer. Conventional methods for G-quadruplex DNA structure separation are time-consuming, environmentally unfriendly, and low throughput. Thus, there is a pressing need for alternative methods of separation to be developed for G-quadruplex DNAs. Here we present work in designing a separation method using the capillary electrophoresis instrument. Capillary electrophoresis is a highly automated, reusable, and quantitative technique that separates analytes based on their size and charge. A capillary method for G-quadruplex separation would be a valuable analytical tool to supplement the biophysical methods available by addressing …

Analysis Of Material Properties For Wooden Octet Trusses, Julio A. Del Cid , '23, David Mendoza , '23

Senior Theses, Projects, and Awards

The introduction of new construction materials has given rise to different, unique construction projects emphasizing architectural value without sacrificing strength, safety, and durability. This project proposed the design for a wooden octet truss along with an efficient fabrication process; furthermore, it studied the plausibility of implementing columns of octet trusses into everyday structures. Compressive loading tests were conducted on each fabricated truss in order to determine its strength properties and areas that could be improved upon in future iterations. In constructing each truss, priority was placed on maximizing load capacity and overall resistance to deformations while reducing both construction time …

The Potential For Mycofiltration Of E. Coli Pollution In The Crum Creek Using T. Versicolor And P. Ostreatus, Kennedy M. Hill , '23

Senior Theses, Projects, and Awards

Mycoremediation is a cost-effective and environmentally friendly alternative to conventional wastewater and drinking water treatment, as well as other environmental remediation methods. This project will design a mycofiltration system using mushroom species T. versicolor and P. ostreatus. Water from a section of the Crum Creek, located in Swarthmore, Pennsylvania, U.S.A, will be sampled and filtered through this system to remove Escherichia coli (E. coli). The mycofiltered water will be compared to the Environmental Protection Agency standards for E. coli concentrations in recreational and drinking water to measure how effective T. versicolor or P. ostreatus may be at removing …

Swimming Robots Using Memory Metal, Joshua R. Heckman , '23

Senior Theses, Projects, and Awards

While in the very early stages of life, Barnacle nauplii are only a few micrometers in length, which causes them to experience a very low Reynolds number while swimming through water. It is important to understand how these biological creatures swim, so their movements can be mimicked and incorporated into robotics. Currently, there are no autonomous underwater vehicles (AUV) that are capable of carrying out missions in fluids with low Reynolds numbers. This project aimed to replicate the movement of a Barnacle Napuli with the use of muscle memory wire, in hopes that one day a AUV that can operate …

Heat Load For The Abc House, Jonathan Odim , '23

Senior Theses, Projects, and Awards

Following the protocol set forth in the ASHRAE 2021 Fundamentals Handbook, this project modeled the heating load of the house for a design season (winter). This project reports the heating load calculation for a 1960 residential dwelling used as student housing in Swarthmore, PA. The infiltration, window, door, attic, 1st-3rd floor, and basement loads were found to be 5641 kW, 3239 kW, 273 kW, 262 kW, 4073 kW, and 514 kW respectively: resulting in a total design season heat load of 14001 kW. The three biggest contributors to the seasonal heat load were Infiltration, Window, and Wall load (40.3%, 29.1%, …

Solar Sonification: From Data To Music With Solar Protocol, Chris O. Stone , '23

Senior Theses, Projects, and Awards

“Solar Sonification” is an interactive python notebook written in Jupyter Labs was designed to utilize data from a solar-powered web server to create and share data sonifications. It is an extension of the global network of solar-powered web servers known as Solar Protocol, one of which was built in 2020-2021 through the Halpern Family Foundation Engineering Design fund. Using this notebook, the participant is able to learn more about the functionalities of the server while engaging in their musical relationships being able to customize the pitches, instruments, and other musical parameters of the output as MIDI files. Files can be …

An Adapted Computational Model For Investigating Muscle Thumb-Tip Movement Patterns For Restoring Grasp Following Tetraplegia, Cole D. Smith , '23

Senior Theses, Projects, and Awards

It is believed that 65-75% of the persons diagnosed with tetraplegia would benefit from reconstructive surgery to regain the ability to perform activities of daily living. This surgery would improve their functional independence and reduce the annual assistive care costs ($80 million) in the US. Tendon transfer surgery, a reconstructive surgical procedure involving surgical transfer of a healthy muscle–such as the pronator teres (PT) or the brachioradialis (Br) muscle–to the paralyzed flexor pollicis longus (FPL) muscle of the thumb, is commonly performed to restore lateral pinch grasp. Functional outcomes, however, have been mixed. Previous research suggests that using muscle combinations …

A Review And Reflection On Open Datasets Of City-Level Building Energy Use And Their Applications, Xiaoyu Jin, Chong Zhang, Fu Xiao, Ao Li, Clayton Miller

Research Collection College of Integrative Studies

Data related to building energy use fuels the research and applications on building energy efficiency, which is an essential measure to address global energy and environmental challenges. However, in most cities, there is a lack of comprehensive and publicly accessible building energy use datasets with necessary temporal and spatial granularities to support urban building energy modeling, regional energy planning, city-level building performance benchmarking, and policymaking on building energy efficiency. Data owners and governments are facing challenges in determining which and how building energy use data should be disclosed at the city level and how to protect data privacy. This review …

A Hybrid Active Learning Framework For Personal Thermal Comfort Models, Duygu Zeynep Tekler, Yue Lei, Yuzhen Peng, Clayton Miller, Adrian Chong

Research Collection College of Integrative Studies

Personal thermal comfort models are used to predict individual-level thermal comfort responses to inform design and control decisions of buildings to achieve optimal conditioning for improved comfort and energy efficiency. However, the development of data-driven thermal comfort models requires collecting a large amount of sensor-related measurements and user-labelled data (i.e., user feedback) to achieve accurate predictions, which can be highly intrusive and labour intensive in real-world applications. In this work, we propose a hybrid active learning framework to reduce data collection costs for developing data-efficient and robust personal comfort models that predict users’ thermal comfort and air movement preferences. Through …

Using Thermal Remote Sensing To Quantify Impact Of Traffic On Urban Heat Islands During Covid, My-Thu Tran, Bo Yang

Mineta Transportation Institute

A three-month lockdown in the U.S. at the beginning of the COVID-19 outbreak in 2020 greatly reduced the traffic volume in many cities, especially large metropolitan areas such as the San Francisco Bay Area. This research explores the impact of transportation on climate change by using remote sensing technology and statistical analysis during the COVID-19 lockdown. Using thermal satellite data, this research measures the intensity of the urban heat island, the main driver for climate change during the urbanization process. The research team acquired morning and afternoon MODIS data in the same periods in 2019 before the pandemic and 2020 …

Modeling And Evaluating Alternatives To Enhance Access To An Airport And Meet Future Expansion Needs, Srinivas S. Pulugurtha, Abimbola Ogungbire, Chirag Akbari

Mineta Transportation Institute

The continued growth of air travel calls for the incessant construction effort at many airports and their surroundings. Thus, there is a need to determine how airports can better manage existing infrastructure to accommodate this growth. This study, therefore, focuses on (1) investigating how changes in transportation infrastructure have affected travel time reliability (TTR) of the surrounding road network within the airport vicinity over time, and, (2) exploring selected unconventional intersection designs and proposing new inbound/outbound access routes from the nearby major roads to the airport. The efficiency of road networks that surrounds large airports is discussed using Charlotte Douglas …

Vibration Control Of A Two-Story Base-Isolated Building Using A New Tuned Mass Multi-Sliding Friction Damper, Mohsen Amjadian, Syed Muhammad Bilal Haider

Civil Engineering Faculty Publications

This paper studies the use of a new Tuned Mass Multi-Sliding Friction Damper (TMMSFD) to increase the damping capacity of seismic isolators installed on a two-story base-isolated building to limit their lateral deformations. The proposed TMMSFD consists of a set of several masses that are laterally attached to the superstructure floor through linear springs. These masses are placed on top of each other one by one and are allowed to slide with respect to each other during the earthquake. The bottom mass that carries the weight of upper masses is in contact with the superstructure floor. The damping of system …

Mclaughlin-Walsh Residence Hall Expansion, Rebecca Huang, Shanelle Smith

Civil, Environmental and Sustainable Engineering Senior Theses

An expansion of McLaughlin-Walsh Residence at Santa Clara University was designed to provide additional housing accommodations to on-campus residents. The design included both the structural and geotechnical components. The proposed solution included a vertical expansion of the residence hall with the design of a podium to span over the existing structure to support an additional residential structure. The loads of the additional residential structure were estimated to complete the design of the podium structure. The podium was designed to support the estimated loads using reinforced concrete columns, steel beams, prefabricated trusses, and concrete on metal deck. The podium design was …

South Lake Tahoe Fire Resiliency Project, Kelsi Rice, Wyatt Rich

Civil, Environmental and Sustainable Engineering Senior Theses

Our names are Kelsi Rice and Wyatt Rich. We are Seniors at Santa Clara University and are majoring in Civil, Sustainable and Environmental Engineering. Within our senior year at Santa Clara, it is a requirement that we complete a Senior Design Project. Our Senior Design Project is fire hardening the City of South Lake Tahoe’s (City) utility lines. The last few months we have been analyzing the City's current utility infrastructure and the potential for new utility services to be implemented throughout the City. We have conducted an alternatives analysis to determine that the City of South Lake Tahoe is …