Engineering Commons^™

Cell Surface Coatings For Mammalian Cell-Based Therapeutic Delivery, Pei-Jung Wu

Theses and Dissertations--Chemical and Materials Engineering

The cell plasma membrane is an interactive interface playing an important role in regulating cell-to-cell, cell-to-tissue contact, and cell-to-environment responses. This environment-responsive phospholipid layer consisting of multiple dynamically balanced macromolecules, such as membrane proteins, carbohydrate and lipids, is regarded as a promising platform for various surface engineering strategies. Through different chemical modification routes, we are able to incorporate various artificial materials into the cell surface for biomedical applications in small molecule and cellular therapeutics.

In this dissertation, we establish two different cell coating techniques for applications of cell-mediated drug delivery and the localization of cell-based therapies to specific tissues. The …

Impact Of Conformational Change, Solvation Environment, And Post-Translational Modification On Desulfurization Enzyme 2'-Hydroxybiphenyl-2-Sulfinate Desulfinase (Dszb) Stability And Activity, Landon C. Mills

Theses and Dissertations--Chemical and Materials Engineering

Naturally occurring enzymatic pathways enable highly specific, rapid thiophenic sulfur cleavage occurring at ambient temperature and pressure, which may be harnessed for the desulfurization of petroleum-based fuel. One pathway found in bacteria is a four-step catabolic pathway (the 4S pathway) converting dibenzothiophene (DBT), a common crude oil contaminant, into 2-hydroxybiphenyl (HBP) without disrupting the carbon-carbon bonds. 2’-Hydroxybiphenyl-2-sulfinate desulfinase (DszB), the rate-limiting enzyme in the enzyme cascade, is capable of selectively cleaving carbon-sulfur bonds. Accordingly, understanding the molecular mechanisms of DszB activity may enable development of the cascade as industrial biotechnology. Based on crystallographic evidence, we hypothesized that DszB …

Targeted Illumination Strategies For Hydrogen Production From Purple Non-Sulfur Bacteria, John D. Craven

Theses and Dissertations--Chemical and Materials Engineering

The movement towards a more sustainable energy economy may require not only the generation of cleaner fuel sources, but the conversion of waste streams into value-added products. Phototrophic purple non-sulfur bacteria are capable of metabolizing VFAs (volatile fatty acids)and generate hydrogen as a byproduct of nitrogen fixation using energy absorbed from light. VFAs are easily produced from dark anaerobic fermentation of food, agricultural, and municipal wastes, which could then be fed into photobioreactors of purple bacteria for hydrogen production.

The process of photofermentation by purple bacteria for hydrogen production remains attractive due to the capability of reaching high substrate conversions …

Development Of Magnetic Nanocomposite Materials As Reusable Adsorbents For Chlorinated Organics In Contaminated Water, Angela Gutierrez

Theses and Dissertations--Chemical and Materials Engineering

The constant growth in population worldwide over the past decades continues to put forward the need to provide access to safe, clean water to meet human needs. There is a need for cost-effective technologies for water and wastewater treatment that can meet the global demands and the rigorous water quality standards and at the same maximizing pollutant efficiency removal. Current remediation technologies have failed in keeping up with these factors without becoming cost-prohibitive. Nanotechnology has recently been sought as a promising option to achieve these goals. The use of iron oxide magnetic nanoparticles as nanoadsorbents has led to a new …

Synthesis, Characterization And Applications Of Reduced Graphene Oxide And Composite Membranes For Selective Separations And Removal Of Organic Contaminants, Ashish Aher

Theses and Dissertations--Chemical and Materials Engineering

Among the next generation materials being investigated for membrane development, partially reduced Graphene Oxide (rGO) has received increasing attention from the membrane community. rGO-based nanofiltration membranes have shown promising results in applications such as partial desalination, organic contaminant removal, gas-phase separations, and separations from solvent media. rGO offers a unique platform compared to common polymeric membranes since it can be used for separation applications in both aqueous and organic solvent media. An rGO-based platform could also be utilized to synthesize reactive membranes, giving rGO membranes the additional capability of reactively removing organic contaminants. This research focuses on the synthesis of …

Nanoharvesting And Delivery Of Bioactive Materials Using Engineered Silica Nanoparticles, Md Arif Khan

Theses and Dissertations--Chemical and Materials Engineering

Mesoporous silica nanoparticles (MSNPs) possess large surface areas and ample pore space that can be readily modified with specific functional groups for targeted binding of bioactive materials to be transported through cellular barriers. Engineered silica nanoparticles (ESNP) have been used extensively to deliver bio-active materials to target intracellular sites, including as non-viral vectors for nucleic acid (DNA/RNA) delivery such as for siRNA induced interference. The reverse process guided by the same principles is called “nanoharvesting”, where valuable biomolecules are carried out and separated from living and functioning organisms using nano-carriers. This dissertation focuses on ESNP design principles for both applications. …

The Fabrication And Characterization Of Metal Oxide Nanoparticles Employed In Environmental Toxicity And Polymeric Nanocomposite Applications, Matthew Logan Hancock

Theses and Dissertations--Chemical and Materials Engineering

Ceria (cerium oxide) nanomaterials, or nanoceria, have commercial catalysis and energy storage applications. The cerium atoms on the surface of nanoceria can store or release oxygen, cycling between Ce³⁺ and Ce⁴⁺, and can therefore act as a therapeutic to relieve oxidative stress within living systems. Nanoceria dissolution is present in acidic environments in vivo. In order to accurately define the fate of nanoceria in vivo, nanoceria dissolution or stabilization is observed in vitro using acidic aqueous environments.

Nanoceria stabilization is a known problem even during its synthesis; in fact, a carboxylic acid, citric acid, is …

Small Non-Profit Website And Social Media Efficacy, Juliana Maria Leprich

Graduate Research Theses & Dissertations

This thesis examines the website design and social media platform usage of small non-profit organizations (defined as less than $1M operating budget and less than ten staff). This research will be completed by first reviewing other studies that have been done on marketing in the non-profit sector, then by exploring marketing challenges firsthand through a mini-ethnographic case study as described in the mini-ethnographic case study approach, and finally through the examination of tax and financial data provided by Guidestar. The researcher was involved in website collaboration with The Gracie Center in a volunteer capacity and was employed with the two …

Implementation And Evaluation Of Gated Recurrent Unit For Speech Separation And Speech Enhancement, Sagar V. Shah

Graduate Research Theses & Dissertations

Hearing aids, automatic speech recognition (ASR) and many other communication systems work well when there is just one sound source with almost no echo, but their performance degrades in situations where more speakers are talking simultaneously or the reverberation is high. Speech separation and speech enhancement are core problems in the field of audio signal processing. Humans are remarkably capable of focusing their auditory attention on a single sound source within a noisy environment, by de-emphasizing all other voices and interferences in surroundings. This capability comes naturally to us humans. However, speech separation remains a significant challenge for computers. It …

Highly Efficient Gan-Based Single-Phase Transformer-Less Pv Grid-Tied Inverter, Khaled Alatawi

Electronic Theses and Dissertations

Growing energy demand and environmental concerns have led to an increased interest in renewable energy resources to provide a sustainable and low carbon emission energy supply. Among these renewable energy resources, photovoltaic (PV) systems have been the focus of many scientific researchers. The most vital component of a PV system that needs to be improved is the power converter. Grid-tied transformer-less inverters have gained a lot of interest in recent years because of their higher efficiency, reduced volume and lower cost compared to traditional line transformer inverters.

This dissertation discusses single-phase transformer-less inverter challenges and provides solutions that could lead …

Magnetotransport In Zrte5 Crystals, Maksim Andreevich Sultanov

Graduate Research Theses & Dissertations

ZrTe5 is a topological material that is predicted to have a strain or temperature induced phase transition from a topological insulator state into a Weyl/Dirac semimetal state. In this study I find that there is insufficient evidence to support the claims for the existence of such a phase transition. I performed magnetoresistivity measurements using a Quantum Design Physical Properties Measurement System (PPMS) to measure the transverse and longitudinal resistivities at various temperatures and different strengths and orientations of the magnetic field. The measurement results were analyzed using OriginPro to determine the carrier mobility and density and to determine the temperature …

Energy And Exergy Analysis Of A Thermosiphon And Forced-Circulation Flat-Plate Solar Collector Using Mwcnt/Water Nanofluid, Mahmoud Eltaweel, Ahmed A. Abdel-Rehim

Mechanical Engineering

The scientific community has focused on the use of nanofluids to enhance solar collectors' thermal efficiency. Solar energy is considered an extensively available energy resource with a weak effect on the environment. The flat-plate solar collector is considered to be the most common collector used, but the efficiency of the collector has limitations, such as the low effectiveness of the absorber in terms of energy absorption and the transmission of that energy to the working fluid. The flat-plate solar collector can be enhanced by replacing the working fluid with a nanofluid. Nanofluids are considered new media that exhibit thermophysical properties …

Point-Of-Care Assessment At A Free, Out-Of-Hours Orthopedic Clinic, Whitney M. Graves, Zachary K. Winkelmann, Kenneth E. Games

Clinical Practice in Athletic Training

Access to healthcare is a challenge for many Americans living in rural communities. Hospital systems have created programs and developed models to improve access to care. However, documentation of the role of these clinics serving different populations and various types of communities is quite scarce. The purpose of this article is to describe the patient satisfaction and procedures assessed at the point-of-care during a 14-week, out-of-hours free orthopedic clinic in the Southeastern United States. One hundred and twenty-nine patients attended the orthopedic clinic and completed a patient satisfaction survey following their patient encounter. At the end of the 14-week, 89% …

Synthesis Of Fault Traces In Se Louisiana Relative To Infrastructure, David Culpepper, Elizabeth Chinn Mcdade, Nancye Dawers, Mark Kulp, Rui Zhang

Publications

Geological faulting has been implicated as a contributor to subsidence, coastal land-loss and submergence of marshlands in southern Louisiana. This report reviews whether fault motion, either by slow creep or more sudden slip, can cause deformation of engineered structures resulting in increased infrastructure maintenance and repair costs. The impact of surface, or near-surface, geologic faulting on critical infrastructure is insufficiently documented in southeastern Louisiana, but the state has a vast amount of energy-sector subsurface data that to date has been under-utilized for transportation and other near-surface engineering applications. Recent and on-going work by research groups at Tulane University, University of …

Developing A Commercial Product Using A Consumer Grade 3d Printer, Calvin Smith

All Graduate Theses, Dissertations, and Other Capstone Projects

The development of affordable, quality, consumer grade 3D printers has allowed entrepreneurs to develop new products and start small businesses. As the print quality of consumer grade printers has improved entrepreneurs have been able to develop consumer quality products without the traditional expense of mass manufacturing. This change from mass manufacturing to small scale and custom production has allowed for the growth of small businesses. Websites such as www.etsy.com show hundreds of small businesses based on 3D printing, these businesses showcase thousands of products ranging from useful household items to cosplay. This thesis covers the process of a small business …

Developing A Testing Instrument To Evaluate The Performance Of 3d-Printed Body-Powered Prosthetic Hands, Araz Al-Dawoodi

All Graduate Theses, Dissertations, and Other Capstone Projects

A 3D printed prosthetic hand is an open source technology that became a good substitution for many products in the market. For many reasons, Low-cost, easy made / easy build. As an open source product, 3D printed prosthetic designs are available to anyone around the world, a good option for young children because they need to have a new prosthetic more frequent until they reach the adulthood age. Most families cannot pay a thousand dollars technology. From the research, it found that that there are not enough studies cover the open source wrist body-powered prosthetic. Other studies covered products used …

Managing Variability In Assembly Lines, Sumanth Gokapai

All Graduate Theses, Dissertations, and Other Capstone Projects

Every successful company have a diversified product portfolio based on their customer demand. Though products are branded as different variants, versions etc. most of them are similar products with little variations in their features or functions they perform. With the traditional, product centric approach to handle variation, new techniques like Clone and own were implemented in which engineers pick the most similar one available, copy it, make changes to it and present it as a new variant. Even though this approach employs reuse, but the savings occur once and only once. This project discussed how companies can exploit the commonality …

Nanostructured Materials For Food Applications: Spectroscopy, Microscopy And Physical Properties, Shubham Sharma, Swana Jaiswal, Brendan Duffy, Amit Jaiswal

Articles

Nanotechnology deals with the matter of atomic or molecular scale. Other factors that define the character of a nanoparticle are its physical and chemical properties, such as surface area, surface charge, hydrophobicity of the surface, the thermal stability of the nanoparticle, and its antimicrobial activity. A nanoparticle is usually characterized by using microscopic and spectroscopic techniques. Microscopic techniques are used to characterize the size, shape, and location of the nanoparticle by producing an image of the individual nanoparticle. Several techniques, such as scanning electron microscopy (SEM), transmission electron microscopy/high resolution transmission electron microscopy (TEM/HRTEM), atomic force microscopy (AFM) and scanning …

Techno- Economic Feasibility Study Of Solar Water Pumping For Public Facilities In Nigeria, Anamika Singh

Cal Poly Humboldt theses and projects

This thesis presents a techno-economic feasibility analysis of solar water pumping systems in public facilities located in rural parts of Nigeria. Three different public facilities namely, a primary health care center in Ibwa (PHC, Ibwa), a comprehensive health care center in Kwali (CHC, Kwali), and the LEA Primary School in Mapa (LEA School, Mapa), all located in Federal Capital Territory (FCT) of Nigeria, were analyzed. The facilities considered in the study have varying levels of water demand (micro, small, and medium), and they are used as cases to establish the techno-economic suitability of solar water pumping systems to deliver water …

Assessment Of Adaptability Of A Supply Chain Trading Agent’S Strategy: Evolutionary Game Theory Approach, Yoon Sang Lee, Riyaz T. Sikora

Journal of International Technology and Information Management

With the increase in the complexity of supply chain management, the use of intelligent agents for automated trading has gained popularity (Collins, Arunachalam, B, et al. 2006). The performance of supply-chain agents depends on not just the market environment (supply and demand patterns) but also on what types of other agents they are competing with. For designers of such agents it is important to ascertain that their agents are robust and can adapt to changing market and competitive environments. However, to date there has not been any work done that assesses the adaptability of a trading agent’s strategy in the …

Expression, Purification, And Characterization Of Recombinant Basic Fibroblast Growth Factor In Pichia Pastoris, Henry Hieu Minh Le

University of the Pacific Theses and Dissertations

Wounds in the mouth, occurring after oral surgery, take time to heal. No ointment can be added to help with the healing process because mouth saliva will constantly wash it away. In order to combat this problem, we propose engineering a normal flora microbe to grow at the site of injury and secrete a recombinant growth factor to promote healing of the damaged tissue. Our goal is to have the yeast Pichia pastoris produce human basic fibroblast growth factor (bFGF), which aids in cellular proliferation. P. pastoris is a good choice for this application because not only is it considered …

Near Miss Reporting: Perspectives On Worker Conversance Of Incident Events Across Two Industries, Julia Mcgee

University of the Pacific Theses and Dissertations

The practice of reporting workplace incident events is adopted as best practice by organizations and complies with Occupational Safety and Health Administration (OSHA) mandates. Reporting the near miss incident type in which no injury or damage to equipment or the environment occurs is buttressed by the assumption that both the worker and the organization ascribe to the same goal to identify workplace hazards and prevent incident recurrence. The goal of incident reporting is not apparent, and the path to achieving the goal is obstructed by internal and external hazards that act to oppose the reporting process, such that the goals …

Hardware Security In Carbon Based Digital Integrated Circuits, Ahmed Abdelaziz

All ETDs from UAB

Carbon based integrated circuits (ICs) built with Carbon Nanotube Field Effect Transistor (CNTFET) and Graphene Nanoribbon Field Effect Transistor (GNRFET) are established as viable replacement for Silicon based Metal Oxide Semiconductor Field Effect Transistors (MOSFET) in order to meet the demands of future high density ICs with sub-nm channel lengths. Given the inevitability of such development, it is important to establish an understanding of the security vulnerabilities in Carbon based ICs. In this work, we have studied the important hardware security vulnerabilities that plague current MOSFET technology, in CNTFET and GNRFET based ICs. Based on our studies on hardware Trojans …

Spun Prestressed Concrete Pole Options As An Alternative To Wood Utility Distribution Poles, Paula Alvarez Alvarez Pino

All ETDs from UAB

The purpose of this research project is to analyze the current state-of-the-art, including use and design practices, of utility distribution poles and to evaluate the performance of spun prestressed concrete poles with different reinforcement schemes as a viable alternative to wood utility poles. There are an estimated 185 million utility distribution poles in place in the United States, and over 130 million are made out of wood. Most of the existing distribution poles are now approaching or have surpassed their useful lives since they were designed with a life expectancy of 50 years and were installed in the 1950s and …

Accessibility And Decay Of Web Citations In Computer Science Journals, Mohsen Jalali

Library Philosophy and Practice (e-journal)

The aim of this research is to scrutiny the accessibility and decay of web citations (URLs) used in refereed articles published by 27 Computer Science open access journals as indexed by Scopus. To do this, at first, we downloaded 1000 articles of Computer Science open access journals from 2009 to 2018. After acquiring articles, their web citations are extracted and analyzed from the accessibility and decay point of view. Moreover, for initially missed web citations complementary pathways such as using Google search engine are employed. Then, data collected are analyzed using descriptive statistical methods. Research findings indicated that 80.7% of …

Improving Base Metal Electrowinning, Charles Ebenezer Abbey

Doctoral Dissertations

"In zinc electrowinning, Mn oxidizes to form MnO₂ on Pb-Ag anodes, cell walls and pipes. MnO₂ reduces anode corrosion but also leads to short circuits and maintenance issues. MnO₂ is thought to interact with chloride ions and produce oxidized chlorine species. The interactions between Mn and Cl are not well understood. Bench scale experiments were conducted to investigate the effects of the manganese to chloride ratio on anode corrosion rate and electrolyte chemistry using rolled Pb-Ag anodes. Increasing the average Mn/Cl^- ratio from ~7:1 to ~11:1 reduced the anode corrosion rate. Anode scales produced with Mn/Cl …

Transient Multiphase Flow Simulation For Unloading Of Frac Hit Gas Wells, Miguel Angel Cedeno Moreno

Doctoral Dissertations

"This work seeks to develop a fully step-by-step transient multiphase flow simulation valid for unloading gas wells using nitrogen. It studies the behavior of nitrogen for unloading horizontal gas wells with gas injection in the annulus. The work investigates unloading non-Newtonian fluids such as those which invade offset wells when a frac hit occurs during hydraulic fracturing operations in unconventional wells. The effect of varying tubing depth and injection pressure are included in the study.

Results show that as the plastic viscosity increases, the nitrogen volume and time to unload will be increased. As tubing depth increases, the nitrogen volume …

The Effects Of Low Aspect Ratio And Heat Exchanging Internals On The Bubble Properties And Flow Regime In A Pilot-Plant Bubble/Slurry Bubble Column For Fischer-Tropsch Synthesis, Hayder Al-Naseri

Doctoral Dissertations

"Fischer-Tropsch synthesis (F-T) is a process utilized to convert the syngas mixture of CO and H₂ to synthetic fuel and chemicals that executed commercially by using the bubble/slurry bubble column reactor. The experimental results reveal that the investigated parameters, in terms the presence of internals, and reducing the aspect ratio and the solids loading, increase the local gas holdup, interfacial area, bubble passage frequency, and decrease the bubble rise velocity, bubble chord length. Meanwhile, the aspect ratio H/D = 4, and 5 provide enough height to established the fully developed flow regime. As a result of the variation in …

Ferrite Characterization Techniques & Particle Simulations For Semiconductor Devices, Nicholas Erickson

Doctoral Dissertations

"This dissertation is divided into three papers, covering two major topics. The first topic, techniques for ferrite characterization, is discussed over the course of two papers. The second topic, particle simulations for semiconductor devices, is discussed in the last paper. In the first paper, the method for extracting permeability from ferrite materials is discussed for the Keysight 16454A permeability extraction fixture, where the ferrite material to be characterized is assumed to be homogeneous. Then the method is updated to account for layered materials. The updated method is verified through full-wave simulations. In the second paper, a planar printed circuit board …

Chemically-Bonded Enamel-Coated Steel Pipelines For Corrosion Protection And Flow Efficiency, Liang Fan

Doctoral Dissertations

"This study is to explore and develop chemically-bonded enamel coating (200-300 um) on steel pipes, when subjected to soil and thermal environments, in order to improve the corrosion protection and safety of hazardous liquid and natural gas pipelines while reducing pressure loss. Out of five types of enamels and their various mixtures, Tomatec slurry and GP2118 powder were selected for steel pipeline applications. They were applied at approximately 810 °C to the inside surface of steel pipes in wet and electrostatic processes, respectively. The thickness and surface roughness of the enamel coating were measured using a gauge and an optical …