Engineering Commons^™

Advances In Repurposing And Recycling Of Post-Vehicle-Application Lithium-Ion Batteries, Charles R. Standridge, Lindsay Corneal, Nicholas Baine

Mineta Transportation Institute

Increased electrification of vehicles has increased the use of lithium-ion batteries for energy storage, and raised the issue of what to do with post-vehicle-application batteries. Three possibilities have been identified: 1) remanufacturing for intended reuse in vehicles; 2) repurposing for non-vehicle, stationary storage applications; and 3) recycling, extracting the precious metals, chemicals and other byproducts. Advances in repurposing and recycling are presented, along with a mathematical model that forecasts the manufacturing capacity needed for remanufacturing, repurposing, and recycling. Results obtained by simulating the model show that up to a 25% reduction in the need for new batteries can be achieved …

On The Scattering Of An Acoustic Plane Wave By A Soft Prolate Spheroid, Joseph Michael Borromeo

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis solves the scattering problem in which an acoustic plane wave of propagation number K1 is scattered by a soft prolate spheroid. The interior field of the scatterer is characterized by a propagation number K2, while the field radiated by the scatterer is characterized by the propagation number K3. The three fields and their normal derivatives satisfy boundary conditions at the surface of the scatterer. These boundary conditions involve six complex parameters depending on the propagation numbers. The scattered wave also satisfies the Sommerfeld radiation condition at infinity. Through analytical methods, series representations are constructed for the interior field …

Maximization Of The Annual Energy Production Of Wind Power Plants By Optimization Of Layout And Yaw-Based Wake Control, Pieter Gebraad, Jared Thomas, Andrew Ning, Paul Fleming, Katherine Dykes

Faculty Publications

This paper presents a wind plant modeling and optimization tool that enables the maximization of wind plant annual energy production (AEP) using yaw-based wake steering control and layout changes. In order to make predictions of wind plant AEP, necessary extensions of the original wind plant wake interaction model include the coupling with a detailed rotor model and a control policy for turbine blade pitch and rotor speed. This coupling allows the prediction of power production with wake effects throughout a range of wind speeds. Results of an optimization study on a wind plant based on the Princess Amalia Wind Park …

Portable High Throughput Digital Microfluidics And On-Chip Bacteria Cultures, Yiyan Li

UNLV Theses, Dissertations, Professional Papers, and Capstones

An intelligent, portable, and high throughput digital microfluidic (DMF) system is developed. Chapter 1 introduces microfluidics and DMF systems. In Chapter 2, a low-cost and high resolution capacitive-to-digital converter integrated circuit is used for droplet position detection. A field-programmable gate array FPGA is used as the integrated logic hub of the system for highly reliable and efficient control of the circuit. In this chapter a fast-fabricating PCB (printed circuit board) substrate microfluidic system is proposed. Smaller actuation threshold voltages than those previously reported are obtained. Droplets (3 µL) are actuated using 200 V, 500 Hz DC pulses. Droplet positions can …

Effect Of Thermal Treatment On High Temperature Deformation Of Alloy Ep-~823, Martin Milburn Lewis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this research topic is to determine mechanical properties of Alloy EP-823 and to provide a mechanistic understanding of its sensitivity to both thermal treatment and performance temperature. EP-823 is a leading target material for accelerator-driven waste transmutation applications. Overall, the tensile test results of Alloy EP-823 indicated a general trend of decreasing mechanical performance with an increase in tempering time. An increase in tempering time had a statistically significant inverse relationship with ultimate tensile strength (UTS) and yield strength (YS). An increase in tempering time did not have a significant effect on elongation and reduction in area. …

Evaluating The Economic Impacts Of The Legislatively Delayed Provisions Of The 5th Edition (2014) Florida Building Code (Final Report), Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

This research provides an assessment of the potential economic impacts of implementing three legislatively delayed requirements of the Florida Building Code, 5th Edition (2014): 1) residential air leakage testing, 2) residential whole-house mechanical ventilation, and 3) two fire service access elevators for applicable buildings.

Assessment Of Noise-Induced Annoyance By Tones In Noise From Building Mechanical Systems, Joonhee Lee, Lily M. Wang

Lily M Wang

Prominent tones in noise generated by mechanical equipment in buildings can cause complaints from occupants in buildings. The ISO 1996-2 and ANSI S1.13 standards describe methodologies and metrics to quantify tonality perception, but the influence of tones in noise on human annoyance and performance is not fully understood yet. This paper investigates annoyance responses of humans while exposed to background noise with tonal components. Twenty participants completed digit span tasks while exposed to noise signals with differing levels of tones and overall loudness. Subjects were also asked to rate their annoyance after completing tasks under each noise signal. The subjective …

The Impact Of Building Acoustics On Speech Comprehension And Student Achievement, Lily M. Wang

Lily M Wang

The movement for improved classroom acoustics has primarily been grounded on studies that show how building acoustics (i.e. background noise levels and room reverberation) affect speech intelligibility, as determined by speech recognition tests. What about actual student learning, though? If students do not understand each spoken word in the classroom perfectly, can they still manage to achieve high scholastic success? This presentation will review two recent studies conducted at the University of Nebraska – Lincoln, linking classroom acoustic conditions to student learning outcomes and speech comprehension (rather than simply recognition). In the first, acoustic measurements in two public school districts …

Determining Annoyance Thresholds Of Tones In Noise, Jennifer M. Francis, Joonhee Lee, Lily M. Wang

Lily M Wang

Building services equipment often produces noise signatures with significant tones in them that can lead to complaints in the built environment. Previous studies have investigated prominence levels of assorted tonal frequencies, but it is still unclear what prominence of the tones across varying tonal frequencies can lead to human annoyance. This project seeks to apply two different methods towards defining annoyance thresholds of tones in noise at two tonal frequencies: 125 Hz and 500 Hz. In the first, subjects are asked to perform a task, while exposed to ten minutes of a broadband noise spectrum with a specific level of …

The Impact Of Building Acoustics On Speech Comprehension And Student Achievement, Lily M. Wang

Lily M Wang

The movement for improved classroom acoustics has primarily been grounded on studies that show how building acoustics (i.e. background noise levels and room reverberation) affect speech intelligibility, as determined by speech recognition tests. What about actual student learning, though? If students do not understand each spoken word in the classroom perfectly, can they still manage to achieve high scholastic success? This presentation will review two recent studies conducted at the University of Nebraska – Lincoln, linking classroom acoustic conditions to student learning outcomes and speech comprehension (rather than simply recognition). In the first, acoustic measurements in two public school districts …

Effects Of Room Acoustics On Comprehension Of Foreign-Accented Speech By Native And Non-Native English-Speaking Listeners, Zhao Peng, Kristin E. Hanna, Brenna N. Boyd, Lily M. Wang

Lily M Wang

In a previous study by the authors, reverberation time (RT) and background noise level (BNL) were both found to have negative effects on native and non-native English-speaking listeners in comprehending English speech produced by native American-English-speaking talkers. Comprehension scores were adjusted for listeners’ baseline English proficiency levels. In the present study, instead of native English-speaking talkers, two native Mandarin Chinese talkers (one male, one female) with similar English spoken proficiency were recruited to produce the same speech materials used in the previous study. A similar methodology was adopted to conduct speech comprehension tests on three groups of listeners: 1) native …

Quantification And Subjective Perception Of Varying Reflection Densities In Measured Room Impulsed Responses, Hyun Hong, Lily M. Wang

Lily M Wang

This project focuses on quantifying and testing the subjective perception of reflection densities, or the number of reflections per second, from different room impulse responses. The widely used room acoustic metric, reverberation time, is linked to the perceived reverberation in a room. Two different rooms having the same reverberation time, though, can have different reflection densities in their room impulse responses, and this difference in reflection density may affect how listeners perceive spatial impression in rooms. To investigate how sensitive humans are to a change of reflection density, this paper first reviews assorted parameters for quantifying reflection density from measured …

Room Acoustic Effects On Speech Comprehension Of English-As-Second-Language Talkers And Listeners Versus Native-English-Speaking Talkers And Listeners, Lily M. Wang

Lily M Wang

Approximately 21% of the children in the United States school system speak a language other than English at home, but are being taught in English at school. English is additionally being used more and more often as a common language in international settings, even though participants at these international events again are not native English speakers. How do adverse room acoustic environments, including higher background noise levels and longer reverberation times, impact English-as-a-Second-Language (ESL) talkers and listeners versus native English-speaking talkers and listeners? This presentation focuses on two recent studies at the University of Nebraska that investigate how assorted room …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering News (2013-2023)

• Dr. Mitra Honored by PLTW

Ubisol-Q10 Prevents Glutamate-Induced Cell Death By Blocking Mitochondrial Fragmentation And Permeability Transition Pore Opening, Santosh Kumari, Suresh L. Mehta, Gaolin Z. Milledge, Xinyu Huang, P Andy Li

Faculty Publications

Mitochondrial dysfunction and oxidative stress are the major events that lead to the formation of mitochondrial permeability transition pore (mPTP) during glutamate-induced cytotoxicity and cell death. Coenzyme Q10 (CoQ10) has widely been used for the treatment of mitochondrial disorders and neurodegenerative diseases. Comparing to traditional lipid-soluble CoQ10, water soluble CoQ10 (Ubisol-Q10) has high intracellular and intra-mitochondrial distribution. The aims of the present study are to determine the neuroprotective effects of Ubisol-Q10 on glutamate-induced cell death and to explore its functional mechanisms. HT22 neuronal cells were exposed to glutamate. Cell viability was measured and mitochondrial fragmentation was assessed by mitochondrial imaging. …

Evaluation Of Alternative Implementation Methods Of Failure Sampling Approach For Structural Reliability Analysis, Kapil Patki, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

In this paper, several alternative approaches are used to implement the failure sampling method for structural reliability analysis and are evaluated for effectiveness. Although no theoretical limitation exists as to the types of problems that failure sampling can solve, the method is most competitive for problems that cannot be accurately solved with reliability index-based approaches and for which simulation is needed. These problems tend to have non-smooth limit state boundaries or are otherwise highly nonlinear. Results from numerical integration and three extrapolation approaches using the generalized lambda distribution, Johnson's distribution, and generalized extreme value distribution are compared. A variety of …

Improving Radiation And Stress Corrosion Cracking Resistance Of Austenitic Stainless Steels By Laser Shock Peening, Qiaofeng Lu

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Structural alloys for Generation-IV nuclear reactors need to endure a high neutron dose, high temperature, and corrosive coolant. Austenitic stainless steels, particularly the oxide-dispersion-strengthened (ODS) austenitic steels, are promising candidate materials, but they suffer several limits such as irradiation damage and stress corrosion cracking (SCC). This research applies a laser shock peening (LSP) process to improve the radiation and SCC resistance of austenitic stainless steels in simulated nuclear reactor environments. A high density dislocation networks, stacking faults and twin boundaries were generated in the surface region of 304 steels by the shock wave-material interactions in the LSP process. In-situ TEM …

Automated Mini-Channel Platform For Studying Plant Root Environments, Kevin F. Kreis

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Plants are crucial to our lives; they provide us with building materials, oxygen, and food. A season’s crop yield can be significantly affected by local environmental factors. Farming practices currently focus on using fertilizer, pesticides, monitoring water availability, and genetic modification of the plant to increase crop yield. Improving fundamental understanding of plant root interactions with their local soil environment, or rhizosphere, will help improve crop yield. Studying such interactions is challenging because roots are underground, making it difficult to observe interactions and to manipulate the local soil environment.

The goal of this thesis is to develop an automated mini-channel …

Ascanius Project: Mech 401/402 Senior Capstone Experience, Ray H. Colquhoun, Joshua Solberg, Martin Tangari, Emanuel Di Stasio

Honors Thesis

This report describes the analysis, design, and test, and launch of a high power reusable rocket. The design goals were to reach a target altitude of 3000’, deploy a payload module containing an egg that can be safely recovered, and record flight video. The rocket was 62.13 in long fully assembled, had a dry mass of 2.764 kg (3.077 kg wet), and was propelled using an I-class solid fuel rocket motor (Cesaroni I-216-CL). The nose cone and tail cone were fabricated by the team from carbon fiber reinforced polymer (CFRP) via wet layup and vacuum bagging. The fins were constructed …

Least Cost Analysis For Solar Photovoltaic Maintenance Of The Wmu Miller Auditorium Array, Kelsey Pitschel

Honors Theses

The solar photovoltaic array at Miller Auditorium is a 50 kW DC system that has relied on five seasonal angle adjustments and no cleaning measures to reach an average of 64.7 MWh annual energy generation since 2012 1 . This amount of energy generation yields $7,046 in annual energy savings based on current market pricing for end use electricity of $0.1089/kWh 2 . The current adjustment schedule based on seasonal tilts accounts for an annual costs between $760 and $848, but actual adjustments have historically not taken place according to the existing schedule. The analysis focuses on optimizing net energy …

Design Of Medical Devices For Diagnostics In The Gastrointestinal System, Charles R. Welch

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis presents the design, controls, and testing of two systems: a novel colonoscope locomotion design for diagnostics, and a biosensor capsule that implants a sensor in the small intestine. Each system requires special design considerations for use in the gastrointestinal system.

Colonoscopy procedures are recommended as a screening for colon cancer and related conditions after the age of 50. The need for an improved colonoscope that reduces the colonoscopy time and patient discomfort is apparent. The semi-autonomous device presented here could likely reduce the colonoscopy procedure time by allowing the physician to focus more on the diagnosis and less …

Experimental Investigation Of The Melting Behavior And The Transient Heat Transfer In A Phase Change Material (Pcm), Mohammad A. Bashar

Electronic Thesis and Dissertation Repository

Phase change materials (PCMs) used in thermal energy storage (TES) system as heat storage media can play crucial role in various engineering applications. PCMs have the inherent ability to store large amount of heat by exploiting their heat of fusions, predominantly during their solid-liquid phase-change period. The present study reports an experimental investigation on the melting process in a PCM and the associated heat transfer in a transient manner. The experiments were conducted in a rectangular chamber filled with paraffin wax used as the PCM and, a cylindrical copper tube with different geometries and orientations as the heat source.

The …

Spinal Implant Design And Subsidence, Schuyler E. Price, Lorrin Schoeneweis, Hannah Steele, Matthew Shomper, Timothy L. Norman

The Research and Scholarship Symposium (2013-2019)

A spinal implant may be used in people who have diseased or injured intervertebral discs pushing against their spinal cord and nerves, causing them loss of sensation due to nerve impingement. Patients who have not found relief through non-surgical means may require a discectomy, which removes the disc and relieves the pressure. There are several ways to then fill the resulting gap which include fusion devices, artificial disc replacement (ADR) devices, or bone grafts. Our study focused on the first two mechanical options.

Subsidence, or the vertical movement of the device into the adjacent vertebral bodies, is an often reported …

Squeaver, Cole Stonebrook, Matthew Frana, Samuel Tabor

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Overhanging limbs pose a threat to many homeowners with trees in their yard. If these limbs fall, property damage and personal injury are a major possibility. Currently the two methods used to cut and remove these limbs are hiring a tree service to use a boom truck to lift an arborist up to the limb or having a tree climber cut and lower the limb. Both methods are unsafe and expensive. Our design will be a tree-trimming device that can be rented from an equipment rental facility and operated by the homeowner. The machine will have the capability to extend …

Leidenfrost Energy Barriers, James Peck, Anton Hassebrook, Craig Zuhlke, Troy P. Anderson, Dennis R. Alexander, George Gogos, Sidy Ndao

UCARE Research Products

In this work, an “Energy Barrier” was created to control the motion of Leidenfrost droplets. This barrier was created by functionalizing a portion of a mirror-polished stainless steel 304 surface with Femtosecond Laser Surface Processing (FLSP). FLSP results in superhydrophilic, hierarchical, micro- and nanostructures which are highly wetting and thus have an increased Leidenfrost temperature. Water droplets in the film boiling state were deposited, and propelled by gravity towards the Energy Barrier interface. Room temperature droplets were deposited over a range of surface temperatures beginning with the Leidenfrost temperature of mirror-polished stainless steel 304 and culminating at the Leidenfrost temperature …

Method For Determining Time-Resolved Heat Transfer Coefficient And Adiabatic Effectiveness Waveforms With Unsteady Film Cooling, James L. Rutledge, Jonathan F. Mccall

AFIT Patents

A new method for determining heat transfer coefficient (h) and adiabatic effectiveness (η) waveforms h(t) and η(t) from a single test uses a novel inverse heat transfer methodology to use surface temperature histories obtained using prior art approaches to approximate the h(t) and η(t) waveforms. The method best curve fits the data to a pair of truncated Fourier series.

Human-Assisted Fluid Power Vehicle, Aaron Huntoon

Honors Theses

The rising cost of energy has prompted industrial and technology companies to research and implement renewable or green energy sources in every aspect of their business. This green technology can consist of sources such as: solar, wind, fluid, or others to create energy from renewable sources. The use of these various sources reduces the pollution associated with standard methods of energy development, and it will ultimately drive costs down to benefit the general population. One of the largest benefactors to the use of renewable energy sources is the transportation industry. Billions of people rely on various modes of transportation every …

Designing An Accessible Hall Effect Thruster, Matthew Baird

Honors Theses

A group of three Mechanical Engineering students have selected to design a 200 W Hall Effect Thruster to fulfill the Mechanical and Aeronautical Engineering senior design project. Preliminary studies were performed on the theory behind electric propulsion and plasma physics. The group designed the Western Hall Thruster and used COMSOL Multiphysics® simulation software to refine the magnetic circuit. The group then fabricated and performed magnetic testing of their thruster in Western Michigan University’s Aerospace Laboratory for Plasma Experiments. This testing will seek to prove that a standard research HET can be built by universities without substantial financial resources.

Numerical Investigation Of Full Scale Thunderstorm Downbursts: A Parametric Study And Comparison To Meteorological Model, Christopher Oreskovic

Electronic Thesis and Dissertation Repository

A series of Large Eddy Simulations using an atmospheric meteorological cloud model have been used to investigate the important geometric and thermal parameters that influence a thunderstorm downburst outflow, as it pertains specifically to the idealized cooling source model. A separate set of Large Eddy Simulations make use of the same idealized cooling source model, in a realistic atmospheric base state using real field sounding data, in an attempt to make a quantifiable comparison to a downburst from a full cloud simulation. Randomness has been added to the cooling source forcing function to mimic the thermal variation in a real …

Wire + Arc Additive Manufacturing, Micheal Santangelo

GS4 Georgia Southern Student Scholars Symposium

Additive manufacturing is a rapidly developing technology which promises to drastically reduce the cost and waste associated with manufacturing parts. However, current systems of additive manufacturing used for creating metal parts which are suitable for use in the aerospace, automotive, and defense industries are complex, expensive, and not robust enough to produce a wide range of part features and geometries. A relatively new method, called wire arc additive manufacturing(WAAM) is a low cost option that can create parts which have a near-net shape, and only require a small amount of post processing before they are ready for use. This system, …