Engineering Commons^™

Modeling And Analysis For Unit Cell Size, Material Anisotropy And Material Imperfection Effects Of Cellular Structures Fabricated By Powder Bed Fusion Additive Manufacturing., Yan Wu

Electronic Theses and Dissertations

Cellular structures are networks of interconnected struts or walls with porosities and are widely found in many natural load-bearing structures such as plants and bones. Cellular structures offer unique functional characteristics such as high stiffness to weight ratio, tailorable heat transfer coefficient, and enhanced mechanical energy absorption, which makes them highly attractive in various engineering disciplines such as biomedical implants, electrodes, heat exchangers, and lightweight structures. There exists an abundance of literatures that have investigated various mechanical properties of various cellular structures such as Poisson’s ratio, elastic modulus, ultimate strength, yield strength, and failure characteristics. Based on the classic cellular …

Development Of A Pediatric Cardiac Assist Maglev Pump For Use With A Universal Driver System., Landon Heath Tompkins

Electronic Theses and Dissertations

Heart failure (HF) remains the leading cause of death, affecting 26 million adults worldwide and 6.5 million adults in the United States. Pediatric HF patients have been a historically underserved population with few options for mechanical circulatory support (MCS) therapy, a leading treatment as an alternative to heart transplantation. To address this clinical need, the Inspired Universal MagLev System is being developed; a low cost, universal magnetically levitated extracorporeal MCS system with interchangeable single-use pumps that will ultimately provide adult and pediatric patients ventricular and respiratory assist therapies. The Inspired Pediatric VAD is the first single-use pump application for this …

Hydration, Shrinkage, Cracking, And Mechanical Properties Of Cementitious Materials With Lignocellulosic Biomass Wastes., Aofei Guo

Electronic Theses and Dissertations

The disposal of lignocellulosic biomass wastes imposes a huge economic and environmental burden on this society. Recycling lignocellulosic biomass wastes and applying them to cementitious materials provides a sustainable and value-added way for both agriculture and concrete industries. To comprehensively identify the effect of lignocellulosic biomass wastes at different scales on cementitious materials, the hydration, shrinkage, cracking, and mechanical properties of cementitious materials with lignocellulosic biomass wastes were studied. Given the three different forms (powders, chips, and fibers) of lignocellulosic biomass wastes in this study, the research was implemented in three stages. In the first stage, hemp powders were collected …

Identifying The Need For Trained Machinists In The Greater Tri-Cities Area, Bradley Stufflestreet

Electronic Theses and Dissertations

Machinists are skilled tradespeople responsible for running a variety of machine tools to produce precision components for end-users or use in other manufacturing. This project identifies the current and future change in the number of machinists in the Tri-Cities area, especially the five-county service area of Northeast State Community College. Using an industry survey, the need for machinists is identified and evaluated to understand local employers’ needs. The results indicate industry needs more machinist to keep up with demand, as 6 out of 14 companies have open positions and, 8 reported difficulty filling openings. Furthermore, most companies are growing or …

Designing An Autonomous Goods-To-Person Order Picking System: From Storage To Pick., Mina Shekari Ashgzari

Electronic Theses and Dissertations

In recent years, there has been an increased growth in e-commerce, which is a special case of a business-to-customer model. Among all the operations for fulfilling online orders, order picking has been the concern of many researchers and practitioners in the field of warehousing and material handling. This is due to very different technical assumptions and service expectations for online retailers compared to the case of business-to-business models. The most fundamental change in order processing, imposed by business-to-customer models, is shipping individual items or “eaches,” instead of cases and pallets, which is typical of business-to-business models. As a result, the …

An Exercise Device Used To Achieve Bone Formation Metrics For The Strengthening Of The Proximal Femur., Sean P. Coyle

Electronic Theses and Dissertations

Lateral falls often lead to hip fracture particularly in the elderly who have low bone mineral density. These fractures frequently lead to indirect mortality soon after injury. Normal use over the course over a lifetime leads to optimized adaptation of the bone in the proximal femur according to normal loading. A lateral fall generates non-normal, lateral loading at the proximal hip where the bone has not adapted to withstand such loading. The resulting fracture is generated by reversed strains on the bone tissue in the femoral neck in the hip in contrast to vertical, quotidian loading. Modern practices for preventing …

Bacteria Analysis By Using A Supervised Machine Learning Algorithm Based On Droplet Microfluidics, Yulder Daniel Angarita

Electronic Theses and Dissertations

Sepsis is a major medical problem and massive resources have been invested in developing and evaluating alternative treatments. Statistics indicate that sepsis causes between one third and one half of all hospital deaths in the United States. Sepsis has a high impact on health care in the US, with direct sepsis costs in 2009 exceeding $15.4 billion. A research study found that a 1-hour delay in appropriate antimicrobial care resulted in a 7% - 10% rise in mortality. Several professional societies seek to reduce sepsis mortality by targeting the timely use of diagnostic tests and antimicrobial therapy. The diagnostic instruments …

Multiphysics Computational Model Of Fluid Flow And Mass Transport In Aneurysm, Tanja Cupac

Electronic Theses and Dissertations

The abdominal aortic aneurysm is progressive, asymptomatic, and can eventually lead to rupture which is a catastrophic event leading to massive internal bleeding and possibly death. AAA cases have been characterized by the development of an intraluminal thrombus (ILT). The ILT correlates with the progression of hypoxia in the arterial wall. The extent that ILT presence reduces oxygen flux to the wall has not been quantified and there is rather a poor understanding of key parameters that can affect thrombus-mediated oxygen transport in AAA. The purpose of this study is to address this gap and to assess the effects of …

Nonlinear Control And Observation Of Full-Variable Speed Wind Turbine Systems., Nicholas Hawkins

Electronic Theses and Dissertations

With increasing concern for the environmental effects of power generation from fossil fuels, wind energy is a competitive source for electrical power with higher efficiency than other clean sources. However, the nature of this power source makes controlling wind turbines difficult. The variability of wind as a source either requires highly accurate measurement equipment or sophisticated mathematical alternatives. In addition to the unknown quantities of the weather itself, the efficiency of power capture at the turbine blades is highly nonlinear in nature and difficult to ascertain. The ability of either determine these troublesome quantities, or control the system despite ignorance …

Model-Based Control Methods To Improve The Power Qualify Of Grid-Connected Single-Phase Inverters., Moath Alqatamin

Electronic Theses and Dissertations

Power electronic converters are commonly used for interfacing distributing generation sources (DGs) to the electrical power system networks. This is necessary because these DGs usually have different output characteristics and cannot be connected directly to the local load and/or the grid. The power electronic front-end converter is an inverter whose dc link is fed by an ac/dc converter or by a dc/dc converter, according to the DG source type. The commercial front-end inverters are designed to operate either in grid-connected (GC) mode or in stand-alone (SA) mode. In the SA mode, the inverter is connected to local load, but in …

Mathematical Models And Analysis For Demand Side Management In Residential Electricity Distribution Networks., Arnab Roy

Electronic Theses and Dissertations

Development of smart grids along with communication technologies have led to the increased attention and adoption of demand side management (DSM) in the residential sector. Among various DSM schemes, demand response (DR) is a market- based mechanism to shave peak electricity consumption at the system level. In the past decade, the academia has seen a growing literature studying load management methodologies for residential consumers. A typical demand response program has three important facets: the energy cost, comfort of the consumers and overall system efficiency. In this dissertation, we investigate and develop models for effective load control to minimize energy cost …

Inventory Management Of The Refrigerator's Produce Bins Using Classification Algorithms And Hand Analysis., Sarah Virginia Morris

Electronic Theses and Dissertations

Tracking the inventory of one’s refrigerator has been a mission for consumers since the advent of the refrigerator. With the improvement of computer vision capabilities, automatic inventory systems are within reach. One inventory area with many potential benefits is the fresh food produce bins. The bins are a unique storage area due to their deep size. A user cannot easily see what is in the bins without opening the drawer. Produce items are also some of the quickest foods in the refrigerator to spoil, despite being temperature and humidity controlled to have the fruits and vegetables last longer. Allowing the …

An Investigation Of The Effect Of Contour Process Parameters On The Surface Roughness And Dimensionality Of Overhanging Features In 17-4 Stainless Steel., Katherine Schneidau

Electronic Theses and Dissertations

The relationship between varying contour settings and part geometry provides insight into the attainable surface roughness and dimensional accuracy of parts fabricated in 17-4 stainless steel via selective laser melting (SLM). Varying the contour settings of laser power (W), scan speed (mm/s), and beam offset (mm) for unsupported inclined bars. The utilization of a coordinate measuring machine (CMM) and surface profilometer quantified the dimensional accuracy and average surface roughness (Ra) for upface, downface, and topface surfaces. Adjusting the laser power and scan speed had minimal affect to surface roughness compared to part geometry. Part dimensionality was affected by the …

Aqueous Redox Flow Batteries With Boron Doped Diamond As An Electrode., Alex M. Bates

Electronic Theses and Dissertations

As the interest and implementation of renewable energy accelerates, so does that of grid energy storage. It is widely believed that a cost-effective energy storage technology will bring about the proliferation of renewable energy. Redox flow battery (RFB) technology represents a promising solution to cost-effective grid energy storage. Compared to other technologies, RFBs have a long lifetime, high efficiency, are non-flammable, significantly reduce cost, and separately scale power and energy. The separation of power and energy enables increased energy capacity by simply adding electrolyte volume. Of the challenges facing RFB technology, one readily apparent is the cost of the active …

Dynamic Analysis And Fabrication Of A Bi-Stable Structure Designed For Mems Energy Harvesting Applications., Masoud Derakhshani

Electronic Theses and Dissertations

Thanks to the rapid growth in demand for power in remote locations, scientists’ attention has been drawn to vibration energy harvesting as an alternative to batteries. Over the past ten years, the energy harvesting community has focused on bistable structures as a means of broadening the working frequency range and, by extension, the effective efficiency of vibration-based power scavenging systems. In the current study, a new method is implemented to statically and dynamically analyze a bistable buckled, multi-component coupled structure designed specifically for low-frequency vibration energy harvesting systems in both macro and MEMS-scale sizes. Furthermore, several micro-fabrication steps using advanced …

Methods For Mass Data Acquisition Of Whiskey Webs., Adam D. Carrithers

Electronic Theses and Dissertations

Whiskey webs are a recently discovered phenomenon in which the monolayer collapse during evaporation of diluted American whiskey results in self-assembled, web-like structures. It was found that the pattern of weblike structures were unique between different American whiskey products. It is desirable to use these unique patterns as a “fingerprint” which can be used to identify whiskeys, their chemical constituents, and perhaps even counterfeits. In pursuit of identifying whiskey products based on their web pattern, it is necessary to have a large database of samples imaged for each product. The device discussed herein is the realization of an apparatus capable …

Characterization Of Photoacoustic Flow Cytometry Signals, Craig Benzinger

Electronic Theses and Dissertations

Photoacoustic flow cytometry has been utilized to clinically determine the presence of melanoma circulating tumor cells (CTCs). Further investigation was conducted into the morphology of detection signals and how they could be manipulated to allow for further classification. Novel features were extracted from waveforms that appear to have strong classification ability. Neural networks were also used to determine classification potential and the creation of feature mapping for future unsupervised classification. Detections were expanded from single waves to a time dependent multiwave event. Waveforms were also determined to be of non-parametric distribution, allowing for classification by neural network but not allowing …

Pilot Study Exploring The Effect Of Targeted Cox-2 Inhibition In Macrophages Responding To Neuronal Injury; Promoting Enhanced Axonal Regeneration, Alyssa Brauckmann

Electronic Theses and Dissertations

Celecoxib nanoemulsion (CXB-NE) has been developed as a macrophage targeted analgesics by Dr. Janjic and her team at Duquesne University, (Janjic et al, 2018; Liu et al, 2020; Saleem et al, 2019b; Vasudeva et al, 2014). The CXB-NE nanoemulsion carrying a Nonsteroidal Anti-inflammatory (NSAID) inhibitor of COX-2 activity result in a reduction in PGE2 expression in macrophages. Using CXB-NE in rats that have peripheral nerve injury constricting the sciatic nerve relieves hypersensitivity, a pain-like behavior. The treatment also decreases inflammation associated with this chronic constriction injury (Janjic et al, 2018; Saleem et al, 2019b; Stevens et al, 2019). In this …

Identification Of Human Adrenal Carcinoma Cells Using Photoacoustic Flow Cytometry, Alexis Stahl

Electronic Theses and Dissertations

With consistently high mortality rates in patients with adrenal cancer, lack of early detection and diagnosis are an ever increasing problem in fighting the deadly disease. Currently, very few patients are diagnosed with adrenal cancer within the early stages due to the absence of symptoms until large tumors are formed, which is in most cases is fatal. Because of this, early detection equipment is crucial to optimizing the survival rate in patients. We studied the absorbance wavelength of human adrenal carcinoma cells, as well as the minimum cell concentration needed in samples using photoacoustic flow cytometry (PAFC). PAFC generates ultrasonic …

Experimental And Numerical Study Of Process Parameters Effects Towards Part Quality And Porosity During Powder Bed Additive Manufacturing Processes., Subin Shrestha

Electronic Theses and Dissertations

Powder bed additive manufacturing (PB-AM) process utilizes an electron beam or a laser as a heat source to melt the metallic powder particles. These processes have the capability of freeform fabrication, however certain defects such as porosity, high surface roughness, etc. would hinder its application. It is important to understand the effect of the process parameters and the underlying physical phenomena, which lead to the formation of such defects. In this regard, a three-dimensional (3D) thermo-fluid model is developed to study the effect of beam speed on the surface morphology during powder bed electron beam additive fabrication (PB-EBAF). Besides, the …

Materials-Processing Relationships For Metal Fused Filament Fabrication Of Ti-6al-4v Alloy., Paramjot Singh

Electronic Theses and Dissertations

Additive manufacturing (AM) is at the mainstream to cater the needs for rapid tooling and small-scale part production. The metal AM of complex geometries is widely accepted and promoted in the industry. While several metal AM technologies exist and are matured to a level where expectation in terms of design and properties are possible to realize. But the metal AM suffers from the heavy expense to acquire equipment, isotropic property challenges, and potential hazards to work with loose reactive metal powder. With this motivation, the dissertation aims to develop the fundamental aspects to print metal parts with bound Ti-6Al-4V powder …

Selective Laser Melting 17-4 Ph Stainless Steel And The Effect Of Varied Thermal Treatments On Fatigue Behavior., Sean Daniel Dobson

Electronic Theses and Dissertations

Fatigue failure is the leading source of loss in industry. In order for new means of manufacturing to move towards mainstream use a complete understanding of material and mechanical behavior must be gained. This endeavor seeks to aide in that task by observing the fatigue behavior of selective laser melting (SLM) additive manufacturing (AM) specimens and the effect of differing thermal treatment conditions for an optimized AM process. Stainless steel 17-4 PH specimens were fabricated using SLM AM and thermally treated to three conditions: as-built, solutionized and hardened, and direct hardened. These specimens were characterized for material (powder quality, density, …

Experimental Evaluation Of Heat Leak And Convective Heat Transfer In A Household Freezer., Catherine E. Berghuis

Electronic Theses and Dissertations

Heat leak into household refrigerated cabinets is a key driver affecting energy consumption and efficiency of the cooling system. Additionally, knowledge of heat transfer coefficients of internal surfaces is valuable in the development of cabinet and system level performance simulations. Several studies have examined heat leak of refrigeration units using heat flux sensors (HFS); however, no such studies have used heat flux measurements to derive convective heat transfer coefficients of the refrigerated unit walls. The goal of this study is to evaluate the use of HFS to quantify heat leak into a 490-liter freezer and determine the wall convective heat …

Gridhub: A Grid-Based, High-Density Material Handling System., Gang Hao

Electronic Theses and Dissertations

In the past twenty years, the share of e-commerce has increased (FRED, 2019). Since more and more activities, such as picking and sorting customers’ orders, are done in warehouses, high efficiency warehouses are in demand. Furthermore, the efficiency of warehouses is related to customer satisfaction (Colla and Lapoule, 2012). Storage systems are key components in warehouses, which are related to the efficiency of warehouse operations. In this dissertation, we address an automatic puzzle-based storage system under decentralized control. We call this system GridHub. GridHub meets standards of Industry 4.0 (Lasi et al., 2014), and it features high throughput with parallel …

Computational Techniques In Medical Image Analysis Application For White Blood Cells Classification., Omar Dekhil

Electronic Theses and Dissertations

White blood cells play important rule in the human body immunity and any change in their count may cause serious diseases. In this study, a system is introduced for white blood cells localization and classification. The dataset used in this study is formed by two components, the first is the annotation dataset that will be used in the localization (364 images), and the second is labeled classes that will be used in the classification (12,444 images). For the localization, two approaches will be discussed, a classical approach and a deep learning based approach. For the classification, 5 different deep learning …

Influences Of Material Extrusion Additive Manufacturing (Meam) Parameters And Additives On Polyvinylidene Fluoride (Pvdf) Properties., Niknam Momenzadeh

Electronic Theses and Dissertations

Beyond the beneficial characteristics of smart polymers associated with all polymers such as flexibility and cost fabrication, smart materials exhibit multifunctional behaviors. The prospect of integrating structural and sensing/actuation capabilities into a single structure gives design engineers an ability to innovate highly novel, multi-functional creations. Polyvinylidene Fluoride (PVDF) is one of the widely used multi-functional materials which offers a variety of desirable material properties. It possesses exceptional chemical and UV resistance, biocompatibility, low processing temperature and affordable price making it a competitive choice for many commercial applications. In addition, among polymers, PVDF is simply the most dominant piezoelectric polymer. On …

A Machine Learning Approach For Allocating Route Cost To Customers For Transportation And Logistics Services., Alison Davis

Electronic Theses and Dissertations

Advancements in big data enabled management practices inspire logistics companies to study deeper into their transportation operations with a data driven approach. One such question asks: How can a logistics firm identify high-cost customers in their service network? In the presence of rich data on routes involving many customers, this thesis develops a framework to allocate a route cost among customers that the route serves, where each route is associated with multiple route features related to the transportation cost. Cost is allocated using the proportional allocation approach in combination with the random forest method in machine learning. First, this framework …

Effects Of Design Autonomy On The Flow Experience, Antonio F Coriano

Electronic Theses and Dissertations

Most modern workplace settings are laden with operating procedures aimed at standardizing action in the name of efficiency. The cost of this standardization is the autonomy of the operator. Mihaly Csikszentmihalyi stated the problem concisely in his 1975 work Beyond Boredom and Anxiety “… [M]ost of the institutions that take up our time…are organized around the assumption that serious work is grim and unpleasant. Because of this assumption, most of our time is spent doing unpleasant things”. An experiment was created to study and better understand how to redress this harmful situation. Sixteen subjects were given a SolidWorks computer-aided design …

Addition Of Fermentation Experiment To Unit Operations Laboratory, Jeremy T. Rone

Electronic Theses and Dissertations

With the growth of the distillery and brewery industries and the potential jobs created for chemical engineers, it is imperative to equip the chemical engineering graduates from the University of Louisville with knowledge of bioreaction kinetics and experience in performing calculations to solve for concentration profiles and reaction rates. To accomplish this, it is recommended to add a fermentation experiment to the Unit Operations Laboratory II course.

Four groups of students from the Spring 2020 Unit Operations Laboratory II course performed the fermentation experiment. They were able to successfully complete all lab requirements as well as analyze the results and …

Labview Improvements And Equipment Redesign Of Unit Operations Distillation Column, Madalyn S Wead

Electronic Theses and Dissertations

Unit Operations labs are important tools to provide hands-on learning with various chemical processes. The distillation lab experiment allows students to connect equations and definitions from textbooks to the physical processes of distillation as they occur. LabVIEW was the software development tool used to create a program to control the distillation column from startup to shutdown. Improvements were made to both the distillation process equipment and the LabVIEW code to create a more interactive lab experience, enhance students’ conceptual understanding of distillation, and prepare students for their future career as chemical engineers.

Equipment addressed included non-linear valves, malfunctioning temperature and …