Engineering Commons^™

Designing Particle Tracking Software For A Theoretical Understanding Of Magnetic Janus Particle Aggregation, Thomas W. Long

Dissertations and Theses

Magnetic Janus particles are spherical colloids covered with a thin magnetic cap on one half of their surface. The asymmetric magnetic material gives the particles a magnetic dipole shifted away from the center of mass of the particle. The magnetic dipole either points perpendicular (axially-shifted FexOy caps) or parallel (radially-shifted (Co/Pd)x multilayered particles) to the shift vector. When a magnetic field is applied to a system of magnetic Janus particles, the particles aggregate into chains aligned with the magnetic field. The rate of aggregation is of theoretical and practical interest and the focus of the thesis.

Optically studying samples of …

A Dynamic Risk Management Framework For Water And Environmental Sustainability, Arun Ravindranath

Dissertations and Theses

The risks and vulnerabilities facing reservoir systems in river basins shift dynamically over time and space. These risks involve regime changes and shifts, throughout which one observes the transition of water availability from prolonged dry periods to prolonged wet periods. Ensuring reliability of water supply under these hydrological regime shifts involves understanding how these regime shifts can be identified, characterized, and quantified. This dissertation describes a dynamic risk management (DRM) framework for water management at the basin level whose main features are (1) a system of updating risk assessments and policy recommendations on a yearly basis, where the risk assessments …

Development Of Electromagnetic Friction Dampers For Improving Seismic Performance Of Civil Structures, Mohsen Amjadian

Dissertations and Theses

Energy dissipation is critical to limiting damage to civil structures subjected to extreme natural events such as earthquakes. Friction is one of the most reliable mechanisms of energy dissipation that has been utilized extensively in friction dampers to improve seismic performance of civil structures. Friction dampers are well-known for having a highly nonlinear hysteretic behavior caused by stick-slip motion at low velocities, a phenomenon that is inherent in friction and increases the acceleration response of the structure under control unfavorably, in spite of the fact that the displacement is generally reduced because of the energy dissipation. This increase in acceleration …

The Educational Value Of Modelling Complex Thermodynamic Systems With System Dynamics Software, Stephen Crown, Constantine Tarawneh

Mechanical Engineering Faculty Publications

The solution of problems involving complex thermodynamic systems often occupies much of a students' time and can be a distraction from them developing a clear understanding of system components, interaction of subsystems, modelling simplifications and assumptions, and design optimization. Refocusing students on the fundamental concepts of thermal systems design and analysis is possible with the introduction of system modelling software that carries some of the load of repetitive calculation required for complex systems. Models of thermodynamic systems encountered in an advanced undergraduate thermodynamics course were developed by students (some provided to students) to solve homework problems of complex steam power …

Fabrication Of Ultra-Fine Cathodes For Cold-Field Emission, Srujana Valluri

Graduate Research Theses & Dissertations

This thesis discusses the different fabrication steps involved in producing ultra-fine cathodes that are suitable for cold field emission. A four-step nanofabrication process has been developed to obtain the cathodes with tip diameters ranging from 10nm to 20 nm. First, a mask is patterned on a 2-inch silicon wafer using monodisperse 1.18µm silica spheres. These particles are self-assembled using vortex-flow enabled assembly technique to form close-packed monolayers. Then the silicon is etched using a reactive ion etching technique. An inductively coupled plasma etcher is used to perform anisotropic and isotropic etching. The etching recipes used are chosen such that they …

Tools For Understanding Static Structure Factors And Their Application To Simulations Of Liquids, Travis Mackoy

Graduate Research Theses & Dissertations

Molecular dynamics (MD) simulations can be used to compute static structure factors (��(��)) and provide an interpretation of the underlying periodic atomic ordering. MD simulations complement experimentally measured ��(��) by allowing qualitative assignment of peaks to various ordering, such as cation-anion ordering in ionic liquids, via decomposition of ��(��) into partial ��(��). Here we present a method for classifying interatomic distances that allows for quantitative peak assignment and visualization of atoms that contribute most to each peak in calculated ��(��) for soft materials. The method is illustrated by investigating ��(��) for the ionic liquid 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide (C4C1pyrrTFSI), which shows two …

Numerical And Experimental Validation For The Optimization Of Directed Energy Deposition Processing Parameters, Luis Nunez

Graduate Research Theses & Dissertations

In order to capitalize on the cost effectiveness of Metal Additive Manufacturing (MAM) it is critical to understand how to build components with consistency and high quality. Directed Energy Deposition (DED) is a MAM method for creating parts layer by layer through the use of a moving heat source and powder material inserted into the melt pool generated on the substrate. DED like most MAM processes are highly complex due to the rapid thermal gradients experienced during processing. These thermal gradients are determined by a variety of processing parameters which include laser power, powder feed rate, travel speed, layer height …

The Social Presence Of Jibo, Parisa Farhadi

Graduate Research Theses & Dissertations

This research is an attempt to investigate how a social robot is perceived by users at the first encounter. And to find out whether a social robot like Jibo is understood merely as a kind of a technological object or a social entity. Previous studies in Human-Robot Interaction have considered social presence as a mediator in users’ social responses toward robots; however, the focus of this study is the social presence itself and investigates whether Jibo produces a sense of presence during initial encounters. To this end, the current study examines individuals’ perceptions of and responses to Jibo. Participants (N=8) …

Characterization Of Boron/Iron-Oxide Core/Shell Structure For Boron Neutron Capture Therapy By Stem/Eels-Xeds And Mössbauer Spectroscopy, Mason Douglas Hayward

Graduate Research Theses & Dissertations

Boron/iron-oxide core/shell structured nanoparticles were characterized for application in boron neutron capture therapy (BNCT). BNCT is a cancer treatment method using the ability of boron to absorb thermal neutrons and a proposed drug delivery system utilizing an external magnetic field to direct the boron nanoparticles to targeted cancer sites and to extract the used nanoparticles after treatment. Boron nanoparticles were magnetically functionalized by encapsulating with an iron oxide shell. As such the exact composition, size distribution and oxidation states of the core/shell structures can affect treatment efficacy. Characterization was done by electron energy loss spectroscopy (EELS) and x-ray energy dispersive …

Modeling Of Optimized Neuro-Fuzzy Logic Based Active Vibration Control Method For Automotive Suspension, Mohammad Adom Safiullah

Masters Theses

In this thesis, an active vibration control system was developed. The control system was developed and tested using a quarter car model of an adaptive suspension system. For active vibration control, an actuator was implemented in addition to the commonly used passive spring damper system. Due to nature of unpredictability of force required two different fuzzy inference system (FIS) were developed for the actuator. First a sequential fuzzy set was built, that resulted lower vertical displacement compared to basic damper spring model, but system had limited effect with disturbances of higher magnitude and continuous vibrations (rough road). To improve the …

A Kinetic Monte Carlo Study Of Mesoscopic Perovskite Solar Cell Performance Behavior, Behzad Bahrami

Electronic Theses and Dissertations

Perovskite solar cells have received considerable attention in recent years due to their low processing cost and high energy conversion efficiency. However, the mechanisms of perovskite solar cell performance are not fully understood. Models based on probabilistic and statistical approaches can be used to simulate, optimize, and predict perovskite solar cell photovoltaic performance, and they can also guide experimental processing and fabrication conditions to achieve higher photovoltaic efficiency. This work developed a 3D model based on the kinetic Monte Carlo (KMC) approach to simulate 3D morphology of perovskite-based solar cells and predict their photovoltaic performance. The model incorporated the physical …

Static Load Bolted Joint Elastic Resilience Testing Methodology, Paul Melino

Electronic Theses and Dissertations

Elastic resilience is the ratio of deformation over force an object experiences when under stress. Knowing the how much the bolt and clamped part deform under load is critical when determining fasteners for a bolted joint. VDI 2230 is the internationally recognized bolt sizing standard and contains the equations used to determine each of the bolted joint component’s resilience as well as values for embedment estimates based on component surface roughness. Embedment is the local plastic deformation due to uneven contact over the contact planes of a bolt-clamped interface (Bolt head to plate, plate to plate, plate to nut, and …

The Effect Of Curing And Zirconium Content On The Wettability And Structure Of A Silicate Hybrid Sol-Gel Material, Emma Machugh, Maikki Cullen, Alicja Kaworek, Brendan Duffy, Mohamed Oubaha

Articles

Functional hybrid sol-gel coatings have been developed for numerous applications with a wide range of wettabilities. This study proposes to investigate the relationship between the structure and the wetting properties of a zirconium modified silicate hybrid sol-gel coating. The structures of the coatings were altered by varying the content of zirconium, and the curing process, while keeping the sol-gel preparation conditions identical. The structure of the materials was characterized by FTIR, 29Si NMR and SEM. The thermal properties and the wettability are identified by DSC and contact angle measurements, respectively. By corroborating the structural and wettability analyses, it is shown …

Aligning Best Practices In Student Success And Career Preparedness: An Exploratory Study To Establish Pathways To Stem Careers For Undergraduate Minority Students, Kimberly D. Kendricks, Anthony A. Arment, K. V. Nedunuri, Cadance A. Lowell

Journal of Research in Technical Careers

Undergraduate minority retention and graduation rates in STEM disciplines is a nationally recognized challenge for workforce growth and diversification. The Benjamin Banneker Scholars Program (BBSP) was a five-year undergraduate study developed to increase minority student retention and graduation rates at an HBCU. The program structure utilized a family model as a vehicle to orient students to the demands of college. Program activities integrated best K-12 practices and workforce skillsets to increase academic preparedness and career readiness. Findings revealed that a familial atmosphere improved academic performance, increased undergraduate research, and generated positive perceptions of faculty mentoring. Retention rates among BBSP participants …

Introduction For The Special Issue On Beyond The Hypes Of Geospatial Big Data: Theories, Methods, Analytics, And Applications, Qianxing Wang, Allison Kealy, Shengjie Zhai

Mechanical Engineering Faculty Research

We live in the era of ‘Big Data’. In particular, Geospatial data, whether captured through remote sensors (e.g., satellite imagery) or generated from large-scale simulations (e.g., climate change models) have always been significantly large in size. Over the last decade however, advances in instrumentation and computation has seen the volume, variety, velocity, and veracity of this data increase exponentially. Of the 2.5 quintillion (1018) bytes of data that are generated on a daily basis across the globe, a large portion (arguably as much as 80%) is found to be geo-referenced. Therefore, this special issue is dedicated to the innovative theories, …

A Graph-Based Reinforcement Learning Method With Converged State Exploration And Exploitation, Han Li, Tianding Chen, Hualiang Teng, Yingtao Jiang

Civil and Environmental Engineering and Construction Faculty Research

In any classical value-based reinforcement learning method, an agent, despite of its continuous interactions with the environment, is yet unable to quickly generate a complete and independent description of the entire environment, leaving the learning method to struggle with a difficult dilemma of choosing between the two tasks, namely exploration and exploitation. This problem becomes more pronounced when the agent has to deal with a dynamic environment, of which the configuration and/or parameters are constantly changing. In this paper, this problem is approached by first mapping a reinforcement learning scheme to a directed graph, and the set that contains all …

Analysis Of Radiation Damage In Electronics Of Unmanned Aerial And Ground Robotic Platforms, Monia Kazemeini, Alex Barzilov, Woosoon Yim, Jean Chagas Vaz

Graduate & Professional Student Association Research Forum

• Radiation measurements are necessary for a routine monitoring of nuclear facilities and during emergencies, such as the Fukushima Daiichi nuclear power plant accident

• Robotic platforms are utilized to carry radiation sensors to allow for remote sensing and sampling operations

• Unmanned Aerial Systems (UAS) and Unmanned Ground Vehicle (UGV)

• Robots might be exposed to the ionizing radiation (high dose levels are possible)

• Irradiation causes defects in devices and components leading to malfunctions and limiting the robot capabilities, decreasing its operational time

• The goal is to complete scheduled tasks while the robot is being irradiated

• …

Infection Control In Total Knee Replacement Prosthesis Using Nitric Oxide Releasing Biomaterials, Ashley Widing

Master's Theses

Replacing a weight-bearing joint is accompanied by long procedures, even longer recovery times, and intensive monitoring. This burden increases after infection; a complication requiring revision surgeries and therefore extensive additional recovery time. Infection can present itself at any time during the process, making it hard to predict. Currently, a two-part revision surgery is completed by removing all infected tissue and implanting an antibiotic spacer. The spacer fills the joint gap and is removed prior to the revision total knee replacement. A revision total knee replacement follows the same procedure as the initial surgery. Not only is this detrimental to patient …

Variability Of E. Coli In Streambed Sediments And Its Implication For Water Quality, Sadia Salam

Electronic Theses and Dissertations

Fecal indicator bacteria (FIB), including E. coli, are the number one cause of water quality impairments in the United States according to the USEPA. FIB are used as a predictor to identify the possible presence of pathogens in waterbodies. E. coli is a useful indicator of gastrointestinal (GI) related illnesses from contact with fresh water. While surface water is routinely monitored for water quality, streambed sediments are rarely considered as a source of FIB to the overlying water column. This study focuses on understanding the variation of E. coli concentrations in streambed sediments and the potential impact of sediment sources …

Aluminum And Silicon Metal-Semiconductor-Metal (Msm) X-Ray Photodetector, Cinthya Dallana Barbosa Medina

Graduate Research Theses & Dissertations

The main goal of this research was to construct a metal-semiconductor-metal (MSM) device, that could detect x-rays. The following thesis covers the theory behind MSM devices, as well as the theory of detecting x-rays. More importantly, we showed that aluminum was transparent to x-rays, therefore allowing our MSM device to detect only x-rays.

Both p-type and n-type MSM wafers resulted in the predicted Schottky curve. By analyzing our various configurations, we hypothesis the ideal dimensions for this device configuration. We also showed that the effect caused by the interaction with regular light.

Apart from what was accomplished in this paper …

A Lagrangian-Based Heuristic To Consolidate Perishable Products, Samir Babu Bhetwal

Graduate Research Theses & Dissertations

A consolidation center with multiple suppliers and multiple destinations for a perishable product is considered in this research. Perishable products deteriorate with time and this research includes a deterioration cost to measure this behavior. The model considers a variety of suppliers ranging from small to mid-sized. Due to dependencies of inventory and shipment release decisions, an integrated approach of making the operational decisions is necessary. This coordinated approach considers deterioration cost, inventory cost, and transportation cost.

Tradeoff decisions between different supply chain costs are not straightforward as the problem contains constraints like inventory capacity and transportation constraints from suppliers to …

Wavelet-Eigen Analysis For Customizable Flexion Classifier Based On Electromyography Signals, Luke S. Bonnen

Graduate Research Theses & Dissertations

This research will cover Electromyography (EMG) and its use in prosthetics. There are many upper limb amputees that use EMG to control a prosthetic limb. While many of these prostheses are proportionally controlled, meaning they can control one movement proportional to the EMG amplitude, there is a continual need to improve function for quality of life. Proportional control is traditionally utilized for opening and closing of the hand. It is the desire of engineers to find ways to add more functionality without sacrificing reliability. There are systems that do these additional actions, but they have difficulty with reliability because of …

Effect Of Perturbations On The Dominant Flow Structures In A Rectangular Lid-Driven Cavity With Particle Suspensions, Siva Bolisetty

Graduate Research Theses & Dissertations

The lid-driven cavity is a canonical problem in the field of analytical and computational fluid dynamics. This work is focused on a 2-D rectangular cavity with a length twice the size of its width and consists of an incompressible fluid with a moving upper wall/lid while the rest of the wall boundaries are subjected to fixed, no-slip, zero-velocity boundary conditions. The objective is to investigate the effect of perturbations resulting from particle drag and particle collisions on dominant flow structures of the fluid within this cavity. The dominant flow structures in a rectangular lid-driven cavity constitute a primary vortex, a …

Adenovirus Co-Opts Neutrophilic Inflammation In Order To Enhance Entry Into Epithelial Cells, James Matthew Readler

Browse all Theses and Dissertations

Human adenoviruses (AdV) are double-stranded DNA viruses that can cause a range of diseases. While AdV respiratory infections are often mild and self-limited, severe manifestations such as fulminant pneumonia and acute respiratory distress syndrome (ARDS) are not uncommon. In order to identify potential modalities to treat AdV infections and potentially enhance the effectiveness of AdV vector delivery, a thorough mechanistic understanding of how AdV enters host cells is needed. Previous studies have revealed polarized epithelia, one of the primary targets for AdV respiratory infections, are highly resistant to AdV entry from the apical (luminal) surface. However, upon exposure to interleukin …

Quantification Of Optical Parameters Using Frequency Domain Functional Near-Infrared Spectroscopy (Fd-Fnirs), Christopher W. Davies

Browse all Theses and Dissertations

Near infrared spectroscopy (NIRS) is a non-invasive technique that uses near-infrared light and hemoglobin as the contrast to characterize tissue optical properties, namely optical absorption [����] and scattering [����′ ]. Through this characterization, it is possible to obtain information about the tissue’s oxygenated (HbO) and deoxygenated (Hb) hemoglobin concentrations and oxygen saturation which are important physiological markers for diagnosis and intervention monitoring. Many commercial devices use a continuous wave approach (CW-fNIRS), a technique that simply relies on intensity changes from a constant power laser to determine only relative changes in oxygenation. This is a significant limitation for clinical settings where …

Rescue Of Als Protein Fus Toxicity By Taf, Elliott Hayden

Browse all Theses and Dissertations

Amyotrophic Lateral Scleroses (ALS) is a neurodegenerative disease characterized by the degeneration of upper and lower motor neurons in the brain and spinal cord leading to progressive paralysis and ultimately death within 5 years of symptom onset. Only two drugs are approved by the Food and Drug Administration (FDA) for treating ALS that slow the disease progression by about 3 months. Mutations in the gene Fused in Sarcoma (FUS) cause inherited forms of ALS. FUS is a nuclear, multifunctional RNA-binding protein (RBP) involved in multiple RNA metabolic pathways. Mutations in FUS cause mislocalization of the protein from the nucleus to …

Improve Operating Room Utilization Through Distributed Scheduling Workflow And Automation, Miteshkumar Mahendrabhai Vasoya

Browse all Theses and Dissertations

Operating room (OR) plays a crucial role in health care, contributing more than 50% of the hospital’s revenue and incurring over 35% of the hospital’s expense, ultimately determining the hospital’s profitability. Moreover, because the OR is a primary source of admissions, it is virtually impossible to streamline hospital‐wide workflow without first streamlining patient flow through the OR. Unfortunately, current OR scheduling practices often limit the utilization of OR, one of the most expensive resources in the health care industry, to around 60%. On the other hand, many patients have to wait an excessively long time before their surgeries can be …

The Characterization And Fatigue Life Impact From Surface Roughness On Structurally Relevant Features Produced Using Additive Manufacturing, Eric-Paul Daniel Tatman

Browse all Theses and Dissertations

Additive manufacturing (AM) produces rough surfaces that are detrimental to the mechanical performance of the part. In this work, downward-facing surfaces were fabricated in alloy 718 using laser powder bed fusion and investigated with surface characterization and axial fatigue testing. Coupons with downward-facing surfaces at 45°, 60°, and 75° and flat axial fatigue bars with as-built and machined holes were built. Both specimens were fabricated with three levels of downskin laser power and the coupons with three levels of downskin laser speed. Surface characterization showed roughness increased as the downward-facing angle decreased. Fatigue testing with digital image correlation showed localized …

Long-Term Impact On Environmental Attitudes And Knowledge Assessed Over Three Semesters Of An Environmental Engineering Sequence, Benjamin Michael Wallen, Nathaniel Sheehan, Luke Plante, Erick Martinez, Jeffrey A. Starke

Civil and Environmental Engineering Faculty Research and Publications

The pedagogy employed in a three-course environmental engineering sequence is investigated to determine the efficacy of enabling long-term improvement of knowledge and attitudes toward the environment. These three courses incorporate concepts of the five grand challenges released by the National Academy of Engineering and National Academy of Sciences and increase the breadth of knowledge for T-professionals. Previous studies of lengths from a few weeks to semester long courses evaluated the potential causality among various demographics and environmental knowledge and attitudes. The research presented herein contrasts and compares changes in environmental knowledge based upon a 12-question survey and changes in environmental …

Engaging Undergraduate Students In The Philippines In Photonics Research With A Novel Publication-Driven Online Mentoring Approach, Minella C. Alarcon, Benjamin Dingel, Annelle Chua, Aria Buenaventura, Nathaniel Joseph C. Libatique

Electronics, Computer, and Communications Engineering Faculty Publications

This paper discusses a publication-driven, education-by-research model of engaging undergraduate students in Photonics/Optics/Physics research by requiring that all activities lead to journal publication within a year. It is based on a non-traditional university-industry collaboration arrangement that has the following unique features.

First, it utilizes offshore-based alumni (in the USA) who are active in science and technology research as mentors for the students (in the Philippines) in conjunction with the university professor advisers. We adopt inexpensive online collaboration technologies to support their virtual presence.

Second, our research topic “fuses” uniquely two separate courses of study, namely: (i) the traditional Special Relativity …