Engineering Commons^™

Effects Of Steel Type And Sandblasting Pretreatment On The Solid-Liquid Compound Casting Characteristics Of Zinc-Coated Steel/Aluminum Bimetals, Jesik Shin, Taehyeong Kim, Kyoungmook Lim, Hoon Cho, Daeho Yang, Changyeol Jeong, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

Effects of zinc-coated steel type and steel surface sandblasting pretreatment in the solid-liquid compound casting of layered type steel/aluminum bimetals were investigated. The Zn coating behavior and its effects on interfacial microstructure evolution and fracture mechanism were also discussed. The aluminum fluidity in thin plate type flow channels formed by the steel insert and the mold wall primarily depended on the insert surface roughness and secondarily on the wettability. As-galvanized (GI) steel/aluminum bimetal joints showed the bonding strength of 20 MPa and more, while galvannealed (GA) steels showed poor bonding. The interfacial bonding zone consisted of most Al13Fe4, Al8Fe2Si, Al4.5FeSi …

To Burn-In, Or Not To Burn-In: That’S The Question, Ephraim Suhir

Mechanical and Materials Engineering Faculty Publications and Presentations

In this paper it is shown that the bathtub-curve (BTC) based time-derivative of the failure rate at the initial moment of time can be considered as a suitable criterion of whether burn-in testing (BIT) should or does not have to be conducted. It is also shown that the above criterion is, in effect, the variance of the random statistical failure rate (SFR) of the mass-produced components that the product manufacturer received from numerous vendors, whose commitments to reliability were unknown, and their random SFR might vary therefore in a very wide range, from zero to infinity. A formula for the …

Analysis Of The Forming Characteristics For Cu/Al Bimetal Tubes Produced By The Spinning Process, Kai Jin, Qiwei Yuan, Jie Tao, Joseph P. Domblesky, Xunzhong Guo

Mechanical Engineering Faculty Research and Publications

Tube spinning technology represents a process with high forming precision and good flexibility and is increasingly being used in the manufacture of bimetal composite tubular structures. In the present study, a forming analysis of clad tube and base tube in spinning process was conducted through numerical simulations and experiments. There was an equivalent stress transition on the interface since the stress transmission was retarded from clad tube to base tube. The yield strength became a main consideration during a design bimetal composite tube. Meanwhile, the strain distributions in axial direction, tangential direction, and radial direction were also investigated to determine …

Study Of Various Construction Job Functions To Address Workforce Challenge, Abraham Bonilla, Dhaval Gajjar, Kenneth Sullivan

The Professional Constructor

Lack of construction workforce is one of the most predominant challenges faced by the construction industry. It is predicted that the industry will have a major shortage of skilled labor in the next decade due to the retirement of baby boomers and the lack of new talent entering the industry to replace these baby boomers. To attract young talent into the construction industry, it is critical to make them aware about the industry regarding various job functions as it relates to job satisfaction, compensation and career fulfilment. The purpose of this study is to gain insight of various construction job …

Consumer Perception And Willingness To Pay For Extended New Home Warranties, C. Todd Usher, Joseph M. Burgett

The Professional Constructor

Construction standards and methods for building new homes has improved over the last two decades resulting in significant improvements in energy efficiency, comfort, indoor air quality, and durability of new homes. Despite these improvements, the most common builder warranty for a new home in the United States ranges from 6 months to two years in duration. During the past two decades, manufacturer warranties on other durable goods such as automobiles has increased significantly. This study measures consumer perceptions of extended 12 year new home warranties with a survey completed by 162 adults in the United States. The results indicate that …

Towards Ai Welfare Science And Policies, Soenke Ziesche, Roman Yampolskiy

Faculty and Staff Scholarship

In light of fast progress in the field of AI there is an urgent demand for AI policies. Bostrom et al. provide “a set of policy desiderata”, out of which this article attempts to contribute to the “interests of digital minds”. The focus is on two interests of potentially sentient digital minds: to avoid suffering and to have the freedom of choice about their deletion. Various challenges are considered, including the vast range of potential features of digital minds, the difficulties in assessing the interests and wellbeing of sentient digital minds, and the skepticism that such research may encounter. Prolegomena …

Experimental Study And Modeling Of The Gm-I Dependence Of Long-Channel Mosfets, Michael Fong Cheng

Master's Theses

This thesis describes an experimental study and modeling of the current-transconductance dependence of the ALD1106, ALD1107, and CD4007 arrays. The study tests the hypothesis that the I-gm dependence of these 7.8 µm to 10 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-gm dependence with sub-28% maximum error …

Perturbation Based Decomposition Of Semg Signals, Rachel Huettinger

Master's Theses

Surface electromyography records the motor unit action potential signals in the vicinity of the electrode to reveal information on muscle activation. Decomposition of sEMG signals for characterization of constituent motor unit action potentials in terms of amplitude and firing times is useful for clinical research as well as diagnosis of neurological disorders. Successful decomposition of sEMG signals would allow for pertinent motor unit action potential information to be acquired without discomfort to the subject or the need for a well-trained operator (compared with intramuscular EMG). To determine amplitudes and firing times for motor unit action potentials in an sEMG recording, …

Experimental Optical Pulse Picker For Lawrence Livermore National Lab, Alexander Thomas Wargo

Master's Theses

Proprietary.

Development Of A Myoelectric Detection Circuit Platform For Computer Interface Applications, Nickolas Andrew Butler

Master's Theses

Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems …

Sweep And Taper Analysis Of Surfboard Fins Using Computational Fluid Dynamics, Brandon James Baldovin

Master's Theses

The research presented here provides a basis for understanding the hydrodynamics of surfboard fin geometries. While there have been select studies on fins there has been little correlation to the shape of the fin and its corresponding hydrodynamic performance. This research analyzes how changing the planform shape of a surfboard fin effects its performance and flow field. This was done by isolating the taper and sweep distribution of a baseline geometry and varying each parameter individually whilst maintaining a constant span and surface area. The baseline surfboard fin was used as a template in Matlab to generate a set of …

Wastewater Treatment And Nitrogen Removal In Bench-Scale Photobioreactors Operated With Solids Recycling, Erik Hoffnagle

Master's Theses

This thesis examines the effect of solids recycling on nitrification, organic carbon removal, and algal-bacterial productivity in bench-scale photobioreactors (PBRs) simulating winter pond conditions in San Luis Obispo, California and a 6-acre raceway system in Delhi, California. Two sets of duplicate photobioreactors operated with or without solids recycling were fed primary clarifier effluent (1^oEff) for the first experiment, and facultative pond effluent (FAC) for the second experiment.

In both experiments mean productivity was lower in solids recycled PBRs (3.67 and 2.3 g/m²-day), than in controls without solids recycling (4.15 and 3.9 g/m²-day). When fed …

Design Of A Low-Cost Data Acquisition System For Rotordynamic Data Collection, Gregory S. Pellegrino

Master's Theses

A data acquisition system (DAQ) was designed based on the use of a STM32 microcontroller. Its purpose is to provide a transparent and low-cost alternative to commercially available DAQs, providing educators a means to teach students about the process through which data are collected as well as the uses of collected data. The DAQ was designed to collect data from rotating machinery spinning at a speed up to 10,000 RPM and send this data to a computer through a USB 2.0 full-speed connection. Multitasking code was written for the DAQ to allow for data to be simultaneously collected and transferred …

Strawberry Detection Under Various Harvestation Stages, Yavisht Fitter

Master's Theses

This paper analyzes three techniques attempting to detect strawberries at various stages in its growth cycle. Histogram of Oriented Gradients (HOG), Local Binary Patterns (LBP) and Convolutional Neural Networks (CNN) were implemented on a limited custom-built dataset. The methodologies were compared in terms of accuracy and computational efficiency. Computational efficiency is defined in terms of image resolution as testing on a smaller dimensional image is much quicker than larger dimensions. The CNN based implementation obtained the best results with an 88% accuracy at the highest level of efficiency as well (600x800). LBP generated moderate results with a 74% detection accuracy …

Reviews To Rating Conversion And Analysis Using Machine Learning Techniques, Charitha Chanamolu

Electronic Theses, Projects, and Dissertations

With the advent of technology in recent years, people depend more on online reviews to purchase a product. It is hard to determine whether the product is good or bad from hundreds of mixed reviews. Also, it is very time-consuming to read many reviews. So, opinion mining of reviews is necessary.

The main aim of this project is to convert the reviews of a product into a rating and to evaluate the ratings using machine learning algorithms such as Naïve Bayes and Support Vector Machine. In the process of converting the reviews to a rating, score words are created using …

A Bidirectional Soft-Switched Dab-Based Single-Stage Three-Phase Ac–Dc Converter For V2g Application, Dibaker Das, Nathan Weise, Kaushik Basu, Rohit Baranwal, Ned Mohan

Electrical and Computer Engineering Faculty Research and Publications

In vehicle-to-grid applications, the battery charger of the electric vehicle (EV) needs to have a bidirectional power flow capability. Galvanic isolation is necessary for safety. An ac-dc bidirectional power converter with high-frequency isolation results in high power density, a key requirement for an on-board charger of an EV. Dual-active-bridge (DAB) converters are preferred in medium power and high voltage isolated dc-dc converters due to high power density and better efficiency. This paper presents a DAB-based three-phase ac-dc isolated converter with a novel modulation strategy that results in: 1) single-stage power conversion with no electrolytic capacitor, improving the reliability and power …

Toward A Sustainable More Electrified Future: The Role Of Electrical Machines And Drives, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

This article provided an overview of the broad range of applications in which advanced electrical machines and drives play a key role. There are many applications that require steep change in the performance of electrical machines and drives. In addition to novel topologies and design optimization, a broad range of enabling technologies, including advanced materials and thermal management, will play a key role in meeting the ever-growing requirements of the aforementioned applications. Judging by the breadth of the applications and the very demanding requirements in terms of system footprint, efficiency cost, and reliability R&D efforts in the area of advanced …

Investigation Of Fault-Tolerant Capabilities In An Advanced Three-Level Active T-Type Converter, Ramin Katebi, Jiangbiao He, Nathan Weise

Electrical and Computer Engineering Faculty Research and Publications

A novel fault-tolerant three-level power converter topology, named advanced three-level active T-Type (A₃L-ATT) converter, is introduced to increase the reliability of multilevel power converters used in safety-critical applications. This new fault-tolerant multilevel power converter is derived from the conventional T-Type converter topology. The topology has significantly improved the fault-tolerant capability under any open circuit or certain short-circuit faults in the semiconductor devices. In addition, under healthy condition, the redundant phase leg can be utilized to share overload current with other main legs, which enhances the overload capability of the converter. The conduction losses in the original outer devices …

High Specific Power Electrical Machines: A System Perspective, Ayman M. El-Refaie, Mohamed Osama

Electrical and Computer Engineering Faculty Research and Publications

There has been a growing need for high specific power electrical machines for a wide range of applications. These include hybrid/electric traction applications, aerospace applications and Oil and Gas applications. A lot of work has been done to accomplish significantly higher specific power electrical machines especially for aerospace applications. Several machine topologies as well as thermal management schemes have been proposed. Even though there has been a few publications that provided an overview of high-speed and high specific power electrical machines [1-3], the goal of this paper is to provide a more comprehensive review of high specific power electrical machines …

Hands-Free Ultrasound Transducer Attachment, Christina Harrison, Glenn Farina, Harshveer Dhaliwal

Biomedical Engineering

This document describes a background on current ultrasound technologies and the troubles that have inspired the need for a hands-free ultrasound transducer device, as well as the regulatory requirements, like patents and standard codes, for the intended invention. It also explains the Stage Gate Review process used to project plan the design of the device, a description of the final design and how it was developed, and the IQ/OQ/PQ. The objectives necessary to design this device, in order to meet all the requirements of the sponsor, are also summarized here. The design process including manufacturing instructions, prototype evolution, and the …

Foot Support Taping Device For Off-Loading Wounds, Andres Fojaco Gomez, Mikaela Williams, Josh Pelegrin

Biomedical Engineering

No abstract provided.

Automated Microscope Stage, Corin Nishimoto, Alison Flesch, Theo Anastos

Biomedical Engineering

This document seeks to describe the background information, customer requirements, design specifications, indications for use, selected materials, proposed budget, prototypes, final design, manufacturing processes, and testing methods regarding the CellOptimizer automated microscope stage product.

Slit Lamp Ophthalmoscope Redesign, Michael Hostetler, Austin Mattmiller, Alexis Brewer

Biomedical Engineering

The slit lamp ophthalmoscope is used by ophthalmologists for diagnosis of pathologies in the eye. The device is used for identifying ocular diseases or indications of other possible systemic diseases to treat them before the diseases progress. Redesign of the ergonomics and adjustment mechanisms of the slit lamp ophthalmoscope will attempt to improve the compatibility of the device across a greater variety of patients. The wider headrest tower of 12.75 inches, the wider table cutout of 12 inches, and the 12 inches of extension of the headrest tower creates a better ergonomic fit for the patient and doctor. The wider …

Ideomotion Gait Training Thigh Prompt, Kristin Schmidt, Elizabeth Peterson, Dalton Jennings

Biomedical Engineering

This document serves as our project report at its completion for developing thigh prompts to be used with the LiftWalker. In this document we outline our project from its beginning to end. We describe our process from understanding the background and our customer requirements, transforming these customer requirements into engineering specifications, performing the stage gate process, developing and evolving the design, testing the design, and finally drawing conclusions and making recommendations for the future.

Implementing Unbiased Decision-Making In Construction: A Lean Approach, Somik Ghosh, Michelle Robinette, Howard Tapia

The Professional Constructor

Construction project-teams are frequently faced with the task of decision-making as part of their responsibility. The positive effects of the decisions made at various stages of the projects lead to improved project performances, while negative effects can hinder the performances. The project teams take up the task of decision-making surrounded by multiple criteria, which can be arduous and clouded with subjectivity. This paper presents an approach based on the Lean principle of providing more autonomy to the project-teams and supporting collaborative and decentralized process in pursuit of unbiased decision-making. This Lean way of decision-making is formalized as Choosing by Advantage …

Attracting And Retaining Future Top Performing Employees: A Student Perspective, Julia Allen

The Professional Constructor

This essay provides insight as to how construction companies can both attract and retain top performing employees. By making the standard interview and recruiting processes more personal, construction companies can evaluate potential hires to see is they are a good fit for the company for years to come. Once employees are hired, companies then need to provide opportunities for both personal and professional growth. From personal experiences, I share the characteristics I find most important in an ideal employer and emphasize the importance of having an in-depth, genuine conversation with potential hires.

Attracting And Retaining Top Employees By Placing Proper Value On Their Contribution To The Company, Joseph Franklin Iii

The Professional Constructor

Due to an optimistic economic future, construction companies want to attract and retain the best employees to ensure company success. Because of a larger job market, employees now look for the optimal work values to be met in long-term employment opportunities. Construction companies have many challenges when attracting and retaining top employees in a growing market. Therefore; it is beneficial for employers to consider the evolving work values of employees and for these values to be promoted throughout company culture. Offering employees good value for their contribution to the company attracts and retains top employees.

Social Resources Of Mechanical Contracting Management Personnel, Blake Wentz, Sarabeth Gandara

The Professional Constructor

The construction industry in the United States is projected to grow faster than average compared to other industries through 2026. The Baby Boomer generation is leaving a significant gap in the labor force as they reach retirement. Retention of high quality management personnel is a priority for all companies in the construction industry, including mechanical contracting companies. Firms that fail to retain these employees will be left with an understaffed and underqualified workforce, which will hinder their ability to be competitive in the marketplace. In order to aid in retention efforts, mechanical contracting firms need to focus their attention on …

Essay Winners, American Institute Of Constructors

The Professional Constructor

No abstract provided.

Attracting And Retaining Future Top Performing Employees, Caleb Bardin

The Professional Constructor

The goal of this essay is to explore the key factors that influence top-performing employees’ decisions to change companies or remain with their current employers. A few of these factors are salary and benefits, work environment, and corporate advancement. This essay will address such factors and propose solutions using my own educational and professional experience. A key theme to note is the constant evaluation of employees and workplace environment by employers. No company can hope to be successful or have the best people if this skill is not enhanced and implemented well.