Engineering Commons^™

Thermal Resistance Characterization Of High-Voltage Sic Power Module, Landon Lemmons

Mechanical Engineering Undergraduate Honors Theses

Researchers within the University of Arkansas Electrical Engineering Research Department have embarked on a project aimed at enhancing the thermal performance of high-voltage power modules. To aid in the progress of this project, the design, and development of a thermal tester device are needed. The primary objective of this device is to determine the various thermal properties of high-voltage power modules that the electrical engineering department has developed. Additionally, the project aims to facilitate electrical loading tests on power modules and provide researchers with the means to calibrate the power module in terms of thermal load. This project also possesses …

Design And Scale Model Of Wave Generator For The Testing Of Wave Energy Conversion Devices, Amanda Olla

Master's Theses

As the climate crisis draws more concern, research and development in wave energy as a renewable energy source has increased. Devices such as wave energy converters (WECs) are being researched, tested, and implemented to make wave energy a competitive power source. Testing of these devices is limited due to environmental concerns such as weather, location, and other issues. WECs require testing in a marine environment, however, performing testing in the actual environment may be difficult due to weather, access, mounting, and other issues. To eliminate environmental unknowns from testing, a wave simulator device can mimic wave behavior without the need …

A Multi-Aerial Vehicle Platform For Testing Collaborative Mobility Formation Controllers, Matthew Snellgrove

LSU Master's Theses

Multi-agent systems have potential applications in a multitude of fields due to their ability to perform complex tasks with a high degree of robustness. Decentralized systems are multi-agent systems where sensing, control, and communication responsibilities are distributed amongst the agents giving this scheme a particularly high potential for robustness, adaptability, and complexity; however, this comes with its own list of challenges. Formation control is a topic in multi-agent systems that aims to have the agents moving as a virtual rigid body through space. In the literature, there have been successful implementation of formation control algorithms on robot agents in both …

The Performance Analysis And Optimization Of Wave Energy Converters From Modeling To Basin Testing, Lauren Dickson

Electronic Theses and Dissertations

The successful development and optimization of wave energy converters (WECs) are pivotal to the pursuit of sustainable and renewable energy sources. This thesis explores the elements in a workflow that develops and demonstrates the protocols for the optimization of WECs using a rapid design\build\test procedure. This thesis establishes the characterization of scaled ocean test sites, develops the performance metrics, generates the performance modeling techniques to predict the optimum design geometries which will be produced for final testing, and finally, establishes the basin test plan which will be used to conduct the testing on the optimum design. The findings of this …

Effect Of Surface Fluid Entrapment In A Laminar Flat Plate Boundary Layer, Abigail Hays

Mechanical Engineering Research Theses and Dissertations

For streamlined objects in laminar flow, the drag is dominated by friction drag. To counteract this, the boundary condition of the object can be changed to introduce an apparent slip on the surface. A number of approaches have been proposed for introducing surface slip to reduce drag and viscous resistance in fluid flows. This work investigates a novel approach to providing slip via fluid entrapment in a perforated domain embedded in the surface. The fluid entrapment system uses a cavity underneath the domain to allow entrapment of fluid of the same type, or supply air to the surface perforations in …

Rhea Breast Pump: Implementation Of Biomimicry Technology, Harper Daniels, Leanne James, Laini Reynolds, Courtney Rowe, Julia Yaklich

Interdisciplinary Design Senior Theses

Rhea Breast Pump is an innovative breast pump that implements biomimicry informed technology for a more efficient and comfortable breastfeeding experience. Our design implements a tongue actuator in conjunction with vacuum to mimic the suckling motion of a baby’s mouth, a heating element for pain alleviation, and a soft flange to maximize comfort. The development of this device is motivated by the goal of empowering women, specifically nursing mothers, to maintain their independence and individuality while raising a family. Our team, consisting of all female engineers, strongly believes in and supports the notion that women can and should have the …

Transport Mechanisms In Electrochemical Immunoassay Biosensors With Applications To Sarscov-2 Neutralizing Antibody Detection, Mohammad Karim Dehghan Manshadi

Mechanical Engineering Research Theses and Dissertations

Biosensors are used in diverse applications spanning from clinical diagnosis and drug discovery to environmental and safety monitoring. Among different types of biosensors, electrochemical ones have demonstrated high sensitivity, short detection time, and selectivity with a low cost, and have been widely used to detect various diseases. In this thesis, we have introduced an inexpensive, rapid, sensitive, and quantifiable impedance-based immunosensors to evaluate SARS-CoV-2 neutralizing antibody (NAb), which shows the real protective immunity against COVID-19. We demonstrated that our device enabled assessment of NAb in a physiological buffer with conductivity equivalent to that of blood plasma. This technique can be …

Photonic Sensors Based On Integrated Ring Resonators, Jaime Da Silva

Mechanical Engineering Research Theses and Dissertations

This thesis investigates the application of integrated ring resonators to different sensing applications. The sensors proposed here rely on the principle of optical whispering gallery mode (WGM) resonance shifts of the resonators. Three distinct sensing applications are investigated to demonstrate the concept: a photonic seismometer, an evanescent field sensor, and a zero-drift Doppler velocimeter. These concepts can be helpful in developing lightweight, compact, and highly sensitive sensors. Successful implementation of these sensors could potentially address sensing requirements for both space and Earth-bound applications. The feasibility of this class of sensors is assessed for seismic, proximity, and vibrational measurements.

Nautilus Rov Robot Manipulator, Dana Stefanides, Jenny Huynh, Andrew Stewart, Steven Reimer, Andrew Nguyen, Rebecca Walters, Matt Hayes

Interdisciplinary Design Senior Theses

Global warming and climate change are prevalent issues in today’s society. As a result, research in the ocean, our world’s biggest ecosystem, is imperative in efforts to protect the environment. Santa Clara University’s Robotic Systems Lab contributes to this field through work and developments on remotely operated vehicles (ROVs). An existing ROV system called Nautilus consists of a robot arm, end effector, and storage system in order to collect various types of sediments at a depth of 300 feet. However, the previous system does not meet that requirement. In direct collaboration with researchers within the Monterey Bay Aquarium Research Institute, …

Robotic Arm Extrusion End Effector, Nicholas Viamin, David Blouin, Savannah Hunt, Nico Figueroa

Interdisciplinary Design Senior Theses

This senior design project aims to enhance the capabilities of the Rotrics AIO Desktop Arm (Dexarm) by designing and implementing an extrusion device capable of smooth and consistent extrusion for 3D printing applications. The project focused on ensuring safety, affordability, and ease-of-use for users, while achieving precise control over the extrusion process. Various mechanical and electrical components were carefully selected to ensure compatibility with the Dexarm and to provide optimal performance. To maintain safety, extensive testing and risk assessments were conducted to minimize any potential hazards associated with the extrusion process. To achieve smooth and consistent extrusion, precise control mechanisms …

Additively Manufactured Polymeric Surface-Based Lattice Structures For Vibration Attenuation, Imabin Kelvin Ekpelu

Browse all Theses and Dissertations

The focus of this study was to select triply periodic minimal surface (TPMS) structures made of 3D-printed polymers. The primary variables in this study were: TPMS shape, lattice volume ratio, and lattice material. Vibration absorption was characterized by damping ratio via transmissibility at the system’s natural frequency. The vibration testing was performed using an electro-dynamic shaker, a known mass, an input/control accelerometer, and an output/response accelerometer. The 3D-printed absorber/lattice was mounted to the shaker baseplate and a mass will be mounted on top of the absorber. One accelerometer will be mounted to the shaker baseplate and the other will be …

Icing Mitigation Via High-Pressure Membrane Dehumidification In An Aircraft Thermal Management, Danielle D. Hollon

Browse all Theses and Dissertations

Icing, or the formation of ice from water via freezing or water vapor via desublimation, is a phenomenon that commonly occurs within air cycle-based refrigeration systems and requires thermal control that limits system performance. In aircraft applications icing frequently occurs in the heat exchangers and turbine(s) that are part of the air cycle machine, the refrigeration unit of the environmental control system. Traditionally, water vapor is removed from an air cycle machine via condensing in a heat exchanger and subsequent high-pressure water separation. This approach is not capable of removing all of the vapor present at low altitude conditions, corresponding …

Experimental And Numerical Studies On Laser Hot Wire Cladding By A High-Power Direct Diode Laser, Mingpu Yao

Mechanical Engineering Research Theses and Dissertations

Laser hot wire cladding is an advanced surface modification technology. It has been extensively growing during the last decades due to its high deposition rate, good metallurgical bonding between the substrate and clad layer, low dilution ratio, and small heat-affected zone. There are many kinds of lasers widely used in the laser cladding process. The high-power direct diode laser is widely welcomed because of its high energy efficiency, high electro-optic conversion efficiency, low cost, and high reliability. A rectangular-shaped direct diode laser beam combined with hot wire feeding can achieve a lower dilution depth with a uniform fusion line compared …

Novel Locomotion Methods In Magnetic Actuation And Pipe Inspection, Adam Cox

Mechanical Engineering Research Theses and Dissertations

There is much room for improvement in tube network inspections of jet aircraft. Often, these inspections are incomplete and inconsistent. In this paper, we develop a Modular Robotic Inspection System (MoRIS) for jet aircraft tube networks and a corresponding kinematic model. MoRIS consists of a Base Station for user control and communication, and robotic Vertebrae for accessing and inspecting the network. The presented and tested design of MoRIS can travel up to 9 feet in a tube network. The Vertebrae can navigate in all orientations, including smooth vertical tubes. The design is optimized for nominal 1.5" outside diameter tubes. We …

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an effort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …

Mechanistic Understanding Of Phase Stability, Transformation, And Strengthening Mechanisms In Lightweight High Entropy Alloys And High Entropy Ceramics, Ganesh Walunj

ETD Archive

High-entropy alloys (HEAs) are a novel family of solid-solution alloys that have gained international interest due to their exceptional characteristics. Because of the need from the transportation and defense sectors, lightweight HEAs have attracted researcher’s curiosity as prospective advanced materials. Low-weight high entropy alloy synthesizes using arc melting with a mass ratio of AlCrFeMnTix(0.1,0.15,0.2). The synthesized HEA is comprised of a mixture of body center cubic (bcc) and ordered bcc (L21) solid solution phases. The synthesized HEAs have heat treated at 650C, 800C, and 1150C for 1hr, 4hr after solutionized at 1150C for 2 hr to understand the effect of …

Neurogen: Eeg And Near-Infrared Light Stimulation Device, Louisa Mantilla, Samantha Perez, Michelle Wong

Interdisciplinary Design Senior Theses

Neurodegenerative diseases such as Alzheimer’s, Dementia, and Parkinson’s affect hundreds of millions of people across the nation and world each year. While medications targeting disease pathways have often resulted in debilitating side effects, neurodegenerative diseases may be targeted by common pathways that promote healing of tissues via reduced inflammation, increased perfusion, and increased energy production. Photobiomodulation (PBM) targets all of these physiological processes with non-invasive near infra-red light stimulation and for this application the treatment will be applied to the head. Transcranial PBM has been used to effectively treat neurodegenerative diseases with improved cognitive and motor control outcomes. PBM applied …

Latam Intelligent Filter For Education (Life), Andrew Lemus, Jonathan Woo, Edison Yang, Cinthya Jauregui, Daniel Mccann-Sayles

Interdisciplinary Design Senior Theses

The LIFE system is designed to inspire primary-aged students in Latin American schools to pursue higher education in STEM related fields. We hope the students educate others in their community about the public health implications stemming from the lack of clean water and grow to bring about more lasting solutions to the water crisis. Many family’s lives are stymied by the inability to access clean drinking water, with many students ending up spending hours carrying water or spending time recovering water themselves in lieu of attending school. The LIFE team created a tabletop water filter and pump system accompanied by …

Enhancing Bifacial Pv Efficiency With The Addition Of A Rear Side Reflector, Neila Watson

Honors Theses

Bifacial photovoltaics are an expanding sector of solar electricity production, collecting solar energy on the front, back, and sides of the module. This increases the efficiency by around 10% to 30% over a typical mono facial cell, which only collects sunlight on the front. However, the performance of bifacial PV arrays depends on a variety of factors, including temperature, shadows, solar insolation, and set-up geometry. The geometry is affected by the tilt angle, the azimuth angle, the height from the ground to the panel, and the reflectance from the ground surface. The addition of a reflector, usually white in color …

Resistive Pulse Sensing Of Protein Unfolding And Transport In Solid-State Nanopores, Jugal Saharia

Mechanical Engineering Research Theses and Dissertations

Solid-state nanopore sensors have attracted considerable attraction as a tool for solution-based single-molecule studies and have been successfully utilized for characterization of biomolecules such as nucleic acids, proteins, glycans, viruses, etc. Among these, characterization of proteins has been more challenging due to their charge heterogeneity and the complex energy landscape associated with different protein conformations. Presented in this thesis is the fabrication of solid-state nanopores and their application for characterizing proteins and understanding their transport through nanopores. Fabrication of nanometer-sized pores in Si_xN_y membranes was achieved using the conventional controlled dielectric breakdown method as well as a …

Optical Microresonator-Based Flow-Speed Sensor, Elie Ramon Salameh

Mechanical Engineering Research Theses and Dissertations

Optical sensors have become more prominent in atmospheric measurement systems, with LiDAR instruments deployed on a variety of earth-bound, air-borne, and space-based platforms. In recent years, the interest in the human exploration of Mars has created a substantial push towards reliable and compact sensing elements for Mars exploration missions, particularly during a spacecraft’s entry, descent, and landing stages. Real-time sensors able to reliably measure the craft’s speed relative to the surrounding atmosphere during these stages are thus of great interest. In this dissertation, a proof-of-concept for an optical microfabricated sensor, which leverages the whispering-gallery-mode (WGM) and Doppler shift principles, is …

Design And Nonlinear Control Of A Haptic Glove For Virtual Palpation, Matthew Galla

Mechanical Engineering Research Theses and Dissertations

This dissertation presents the design, kinematic analysis, and nonlinear control of a Haptic Glove for medical elastographic imaging virtual palpation. Of the 13 degrees of freedom present in the index finger, middle finger, and thumb of the hand, the design fixes 4, constrains 2 and controls 6 with pneumatic air cylinder actuators, allowing uncontrolled, but measured motion in the remaining 1 degree of freedom. Nearly linear bijective transfer functions between the actuator positions and joint angles are found in closed form for all 6 actuated joints. A nonlinear, sliding-mode controller that allows each actuator to be controlled by a single …

Mechanistic Undrestanding Of Amorphization In Iron-Based Soft Magnetic Materials, Taban Larimian

ETD Archive

Iron-based magnetic alloys possess very good magnetic and mechanical properties. Among these alloys Fe-Si-B-based alloys show outstanding saturation magnetization and coercivity which makes them great candidates for many industrial applications. Addition of certain elements to the Fe-Si-B base is proven to improve the homogeneity and fineness of microstructure as well as enhance the magnetic behavior of these alloys. In this research work, we have studied the effect of adding copper and niobium to the Fe-Si-B base alloy. Previous studies have shown that magnetic alloys show better magnetic properties when their microstructure consists of nanocrystals embedded in an amorphous matrix. In …

Viability And Accessibility Of Urban Heat Island And Lake Microclimate Data Over Current Tmy Weather Data For Accurate Energy Demand Predictions., Irena A. Weclawiak

ETD Archive

Building Energy Simulations (BES) are necessary for designing energy-efficient systems. Open-source simulation software developed by the Department of Energy (DOE), EnergyPlus (EP) provides Typical Meteorological Year (TMY) weather data that consists of a 15-year average. Two major concerns about this data are the inability to detect extreme conditions and limited data locations. There is a greater number of Microclimate (MC) stations that can be used for simulations, but it involves time-consuming data preparation to match the EP format. This study investigated the effects of Urban Heat Island (UHI) and the MC of Lake Erie. A comparison of the MC data …

An Evaluation And Economic Analysis Of A Water Main Geothermal System In A Residential Space, Brian L. Kohut

ETD Archive

Iron-based magnetic alloys possess very good magnetic and mechanical properties. Among these alloys Fe-Si-B-based alloys show outstanding saturation magnetization and coercivity which makes them great candidates for many industrial applications. Addition of certain elements to the Fe-Si-B base is proven to improve the homogeneity and fineness of microstructure as well as enhance the magnetic behavior of these alloys. In this research work, we have studied the effect of adding copper and niobium to the Fe-Si-B base alloy. Previous studies have shown that magnetic alloys show better magnetic properties when their microstructure consists of nanocrystals embedded in an amorphous matrix. In …

Marine Robot Sample Retrieving System, Valeriya Chulyukina, Noah Villar, Kekoa Blair, Mandeep Singh, Nathan Burke

Interdisciplinary Design Senior Theses

The exploration of our underwater ecosystems is critical. The aquatic ecosystem has a significant effect on human life, yet our understanding of the oceanic environment is severely lacking. Santa Clara University’s Robotic Systems Lab contributes to subsea exploration through its investment in remotely operated vehicle (ROV) technology. This project was done with the guidance of not only professors in the Robotics Systems Lab, but also stakeholders from the US Geological Survey scientists and researchers from the Monterey Bay Aquarium Research Institute (MBARI). Our team goal was to further advance SCU’s efforts by creating a sediment sample collection system consisting of …

Airflow Impact Upon Remote Laser Welding Quality, Baixuan Yang

Mechanical Engineering Research Theses and Dissertations

Laser induced plasma-plume and condensed particles attenuate the laser beam energy, resulting in keyhole instability and lacking penetration. There are various airflow devices that are currently used in both industrial and laboratory laser welding settings to suppress the detrimental effect of plasma plume and hot spatters. A systematic experimental and numerical study is presented in this dissertation that investigates different external airflow effects on the remote laser welding process used in automotive manufacturing applications.

The vertical airflow impact on the remote laser welding was first studied experimentally. The airflow velocity profiles of a coaxial vertical flow device were measured using …

Behavior Of 3d Printed Polymeric Triply Periodic Minimal Surface (Tpms) Cellular Structures Under Low Velocity Impact Loads, Jesse James Leiffer

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Surface-based lattice structures such as triply periodic minimal surface (TPMS) lattices are lightweight structures that are widely being investigated for applications in automotive, aerospace, military, railway, and naval structures. Due to the recent advent of three-dimensional (3D) printing (3DP) technologies, architected cellular materials such as surface- or strut-based periodic lattice cell structures have emerged as a unique class of lightweight metamaterials. These materials possess enhanced strength to weight ratio, high stiffness, exceptional capabilities in reducing noise and vibration, insulating heat, and effective impact energy absorption. Understanding the impact behavior of such materials are important so that they can be reliably …

Refrigeration & Pressure Circuits For The Test Apparatus On Triaxial Properties Of Polymer Foams At Arctic Temperatures, Nathaniel Ackerman

Williams Honors College, Honors Research Projects

The objective of this project is to modify the previous testing apparatus used by Dr. M. Hoo Fatt for exploration of Crushing Behavior of Polymer Foams in Sandwich Structures Operating in Arctic Regions commissioned by the Office of Naval Research and performed under the University of Akron’s Mechanical Engineering testing facilities. To do this, it is required to design a system capable of operating at a constant temperature during a testing cycle, reaching down to -60⁰C. This apparatus must also be compatible with prior equipment, facilities, persons, samples, and media.

Primarily, a copper-tube refrigeration coil design was considered to lead …

Modeling The Tribo-Dynamic Behavior Of Roller Contact, Ali Kolivand

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This study proposes dynamic modeling of lubricated rolling contact and a numerical sub-model for fatigue life prediction of rollers under starved lubrication conditions. Excitation caused by surface defects in rolling disks is numerically calculated and used as a metric in predicting surface pitting failure occurrence. Surface topography of mating surfaces is used as input to the model for determining maximum acceleration, approach velocity, and approach distance of rollers in presence of pits (defects). Resultant bearing force, contacting force versus approach distance are generated and compared for different pit sizes, developing an accurate tool for design purposes. Maximum acceleration and displacement …