Engineering Commons^™

Magnetic Studies Of Multiferroic Heterostructures, Ahmed Rayhan Mahbub

Graduate Theses/Dissertations

Multiferroic heterostructures (MHS) consisting of at least two materials with ferroic properties have been a major focus for researchers recently due to its immense potential in device applications. Almost all MHS use ferromagnetic layers making it a very important research area. In this thesis the magnetic properties of different ferromagnetic heterostructures have been investigated. Different bilayers of hard ferromagnet cobalt ferrite (CFO)-soft ferromagnet lanthanum strontium manganese oxide (LSMO) and hard ferromagnet CFO-antiferromagnet nickel oxide (NiO) were fabricated. Pulsed laser deposition technique was used to deposit the thin films on LAO and sapphire substrates. Purpose of using a hard ferromagnetic CFO …

Direct Potable Reuse Of Wastewater, Lauren Clark

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.⁵ The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there …

Direct Potable Reuse Of Wastewater, Sabrina Castle

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.5 The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there are …

Direct Potable Reuse Of Wastewater, Molly Churchwell

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.5 The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there are …

Removal Of Carbamazepine From Drinking Water, Zachary Wiese

Chemical Engineering Undergraduate Honors Theses

Due to the increasing prevalence of prescription medication over the past few

decades, pharmaceuticals have accumulated in various water sources. This has become a

public health concern because many pharmaceuticals have limited research on the effects

of chronic low-level exposure. According to the World’s Health Organization (WHO),

traces of pharmaceuticals products have been reported in different water sources such as

surface waters, wastewater, groundwater, and drinking water.[1] One pharmaceutical of

interest that has been detected in water sources is carbamazepine. Carbamazepine is a

common pharmaceutical prescribed for the treatment of seizure disorders, neuropathic

pain, and various psychological disorders. It’s mechanism …

Removal Of Carbamazepine From Drinking Water, Paola Marrero-Rivera, Adam Johnson, Jordan Alex Gadberry, Juan Rodriguez, Thomas Krumpolc, Zach Wiese

Chemical Engineering Undergraduate Honors Theses

Due to the increasing prevalence of prescription medication over the past few decades, pharmaceuticals have accumulated in various water sources. This has become a public health concern because many pharmaceuticals have limited research on the effects of chronic low-level exposure.One pharmaceutical of interest that has been detected in water sources is carbamazepine. Carbamazepine (CBZ) is a common pharmaceutical prescribed for the treatment of seizure disorders, neuropathic pain, and various psychological disorders. It’s mechanism of action is “sodium channel blocking,” which is the impairment of conduction of sodium ions in sodium channels. This, in effect, reduces nervous-system conductivity in key areas …

Computational Fluid Dynamics Model For Air Velocity Through A Poultry Transport Trailer In A Holding Shed, Christian Heymsfield

Graduate Theses and Dissertations

Broiler production in Arkansas was valued at over $3.6 billion in 2013 (University of Arkansas Division of Agriculture Cooperative Extension Service). Consequently, improvement in any phase of the production process can have significant economic impact and animal welfare implications. One area of concern for the poultry industry is thermal stress experienced by the birds after arrival at the processing plant and before they are taken in to be processed, during which time they are left to wait in holding sheds. Various cooling strategies exist to mitigate heat stress in holding sheds, but in most cases it is unlikely that they …

Secure Aircraft Maintenance Records Using Blockchain (Samr), Ahrash Aleshi

Doctoral Dissertations and Master's Theses

We propose to enhance the security and transparency of aircraft maintenance records in the aviation industry through the use of blockchain technology. A physical aircraft maintenance logbook is susceptible to being lost or destroyed. A nonexistent aircraft maintenance logbook hurts the confidence in integrity and reputation of the aircraft. Furthermore, fraud can occur through forgery of FAA personnel signatures and the installation of non-official aircraft parts. The scope of this work is to develop a secure blockchain that can store aircraft service records and information in a digital distributed ledger. By keeping the maintenance logbook on a digital ledger, records …

A Novel Magnetorheological Fluid Damper For A Small Spacecraft With Flexible Appendages, Robert Waelchli

Doctoral Dissertations and Master's Theses

Small satellites have become increasingly popular over the past thirty years, particularly since the adoption of the common CubeSat architecture early this century. Because of their restricted volume and electrical budgets however, there are practical limits to the missions that small satellites may adopt. One potential near-term solution to the problem of limited electrical power may be the adoption of larger, flexible solar arrays. However, spacecraft with flexible appendages have historically presented attitude control challenges relating to platform stability given the dynamic response of the flexible components to applied torques. These challenges may be particularly disruptive to a small spacecraft …

Propulsive Battery Packs Sizing For Aviation Applications, Tianyuan Zhao

Doctoral Dissertations and Master's Theses

This thesis derives analytical methods for sizing the propulsive battery packs for designing an electric-driven aircraft. Lithium-Ion (Li-Ion) battery is the primary choice of battery cell chemistry in this thesis research due to its superior specific energy and market availability. The characteristics of Lithium-Ion battery cells are first determined and studied using experimental test results and manufacturers published data. Based on the design requirement to the battery system, the battery sizing will fall into one of the two sizing categories. The first category is power sizing, which requires the battery’s ability to deliver full power demanded by the electric motor. …

Development Of A Small Unmanned Aerial Vehicle Longitudinal Model For Future Flutter Testing, Said S. Hamada

Doctoral Dissertations and Master's Theses

This thesis presents the system identification of the longitudinal motion of a small unmanned aerial vehicle with flexible characteristics. The unmanned aerial vehicle of study is an off-the-shelf aircraft with limited knowledge about the dynamic model. The first task in obtaining a model for flutter testing is determining the rigid body model. Specifically, this thesis will focus in the development of the aircraft and obtaining the longitudinal rigid body model. This involves the assembly and configuration of the avionics and sensors, performing experiments to determine mass and inertia properties and using software tools for aerodynamic analysis to get preliminary values …

An Alternative Method Of Identification Of A Failed Engine In Twin-Engine Propeller Aircraft, Andrey Babin

Doctoral Dissertations and Master's Theses

Previous research has revealed that wrong identification of a failed engine during flight is not an uncommon event in an aircraft cockpit. A number of fatal accidents in the past, including the recent TransAsia Flight 235 accident, resulted from engine misidentification. Most accidents of this type happened on takeoff when pilot workload was at its highest level. This thesis consists of two research studies. For Research Study 1, a survey was created to gather opinions of airline pilots who operate twin-engine turboprop aircraft. Twenty-nine percent of respondents to the survey agreed with the statement that there could be a better …

Vision-Aided Navigation Using Tracked Landmarks, Nicodemus Myhre

Doctoral Dissertations and Master's Theses

This thesis presents vision-based state estimation algorithms for autonomous vehicles to navigate within GPS-denied environments. To accomplish this objective, an approach is developed that utilizes a priori information about the environment. In particular, the algorithm leverages recognizable ‘landmarks’ in the environment, the positions of which are known in advance, to stabilize the state estimate. Measurements of the position of one or more landmarks in the image plane of a monocular camera are then filtered using an extended Kalman filter (EKF) with data from a traditional inertial measurement unit (IMU) consisting of accelerometers and rate gyros to produce the state estimate. …

Homography-Based State Estimation For Autonomous Exploration In Unknown Environments, Andres S. Chavez Armijos

Doctoral Dissertations and Master's Theses

This thesis presents the development of vision-based state estimation algorithms to enable a quadcopter UAV to navigate and explore a previously unknown GPS denied environment. These state estimation algorithms are based on tracked Speeded-Up Robust Features (SURF) points and the homography relationship that relates the camera motion to the locations of tracked planar feature points in the image plane. An extended Kalman filter implementation is developed to perform sensor fusion using measurements from an onboard inertial measurement unit (accelerometers and rate gyros) with vision-based measurements derived from the homography relationship. Therefore, the measurement update in the filter requires the processing …

Experimental Investigation Of Enhanced Damage Resistant Fiber Metal Laminates, Cannelle Metang Tefoung

Doctoral Dissertations and Master's Theses

Fiber metal laminates (FMLs) are hybrid composite structures made from fiber reinforced polymeric materials sandwiched between layers of thin metal alloy sheets. FMLs combine the advantages of metallic materials and fiber reinforced matrix systems. Some of these advantages include: lighter weight, enhanced impact tolerance, improved corrosion resistance, better fire resistance, longer fatigue life, greater tensile strength, easier repair ability and maintainability, etc. The most well-known commercially available FML is GLARE (Glass Laminate Aluminum Reinforced Epoxy), however there are ongoing issues, which include a very high fabrication cost compared to many competing material systems and substantial delamination upon impact and failure. …

Low-Fare Flights Across The Atlantic: Impact Of Low-Cost, Long-Haul, Trans-Atlantic Flights On Passenger Choice Of Carrier, Jennifer Nicole Hunt

Doctoral Dissertations and Master's Theses

Full-service carriers (FSCs) have long ruled the trans-Atlantic market, due to the absence of low fare competition, which has kept airfares high. However, renewed interest in low-cost, long-haul (LCLH) flights was prompted by efficient aircraft, low fuel prices, liberalization of air markets, and low-cost carriers’ growth opportunities. Since 2013, multiple LCLH carriers have commenced trans-Atlantic operations, and their market share has grown to 8%. In response, FSCs are establishing their own LCLH subsidiaries and/or introducing basic economy airfares to more effectively compete in the trans-Atlantic market. The purpose of this dissertation was to further the understanding of LCLH and FSC …

Microgrids: Resilience, Reliability, And Market Structure, Saeed Dehghan Manshadi

Electrical Engineering Theses and Dissertations

This dissertation addresses several challenges corresponding to the operation and planning of microgrids in distribution networks including the formation, energy supply resilience, the contribution of microgrids in the short-term and mid-term operation of bulk power networks and the computational challenges in operation of interdependent infrastructure systems.

An approach to transforming the active distribution network with distributed energy resources into multiple autonomous microgrids is presented in the first section. The distribution network consists of several generation resources and demand entities that could be clustered into autonomous microgrids. Eigen decomposition in the graph spectra of the distribution network is leveraged to determine …

Pid Algorithm Design For Automation Of Eukaryote Fermentation, Madison Mann

Chemical Engineering Undergraduate Honors Theses

Single celled eukaryotic organisms are advantageous in the production of proteins for use in biopharmaceuticals due to their ease of cultivation and manipulation. Because of high cell density during fermentation and an ability to allow post-translational protein modifications, yeast is particularly well-suited. To maximize the specific formation rate of the desired proteins, an optimum specific growth rate of the yeast should be found and maintained. This rate is dependent upon pH, temperature, dissolved oxygen content, and carbon feed rate. Fermentation can be done in a fed batch reactor system, and it is possible to use a Buglab (online biomss) sensor …

A Proposed Process And Economic Analysis For A Manufacturing Facility For Nylon 6,6, Perry Doles

Chemical Engineering Undergraduate Honors Theses

The global nylon market is a multi-billion-dollar industry that has been thriving in recent years due to advances in the process technology and its flexibility as a material. Nylon 6,6 is a versatile material with uses in many industries because of its ability manipulated into many forms. It is commonly used in applications that require heat resistance, chemical resistance, and high mechanical strength. It is commonly used in luggage, car parts, carpets, and many other plastic products that require the properties that nylon 6,6 exhibits. The versatility and demand for nylon 6,6 make it an attractive process for many potential …

Removal Of Carbamazepine From Drinking Water, Jordan Alex Gadberry, Adam Johnson, Juan Rodriguez, Paola Marrero-Rivera, Tom Krumpolc, Zach Wiese

Chemical Engineering Undergraduate Honors Theses

Due to the increasing prevalence of prescription medication over the past few decades, pharmaceuticals have accumulated in various water sources. This has become a public health concern because many pharmaceuticals have limited research on the effects of chronic low-level exposure. According to the World’s Health Organization (WHO), traces of pharmaceuticals products have been reported in different water sources such as surface waters, wastewater, groundwater, and drinking water.^[1] One pharmaceutical of interest that has been detected in water sources is carbamazepine. Carbamazepine (CBZ) is a common pharmaceutical prescribed for the treatment of seizure disorders, neuropathic pain, and various psychological disorders. …

Sulfate Removal From Mine Impacted Waters, Luis Sagarnaga

Chemical Engineering Undergraduate Honors Theses

Woo Pig Sulfate (WPS) has developed two methods for reducing levels of calcium sulfate in mine impacted waters, a “hot process” and a two-stage nanofiltration process. Both processes were designed to treat gypsum saturated water that is currently being pumped via interceptor wells to prevent the spread of a sulfate plume into a nearby community. Each solution was designed for Freeport McMoran’s Sierrita mine in Green Valley, Arizona, which was visited in order to gain insight about the problem. Below 250 ppm on the treated stream, nanofiltration and the hot process achieve overall recoveries of 84 and 99%, respectively. The …

Cross-Linking Amyloid Forming Proteins For Improved Understanding Of Early Aggregation, Gram Booth

Chemical Engineering Undergraduate Honors Theses

Alzheimer’s disease is the only disease in the ten leading causes of death in the United states that cannot be slowed, prevented, or cured. Alzheimer’s dementia and type II diabetes are the top two diseases caused by improper protein folding, aggregation, and deposition of fibrillar plaques in tissues. These plaques, originally thought to be the cause of these diseases, have been discovered to be mostly benign and representative of the later stages of the disease. The smaller, more soluble oligomeric aggregates are responsible for the death of pancreatic and neural cells. Many oligomeric species are unstable and exist only for …

Direct Potable Reuse Of Wastewater, Boyce Bethel

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.⁵ The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there …

Optimizing A System Of Electric Vehicle Charging Stations, Ukesh Chawal

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

There has been a significant increase in the number of electric vehicles (EVs) mainly because of the need to have a greener living. Thus, ease of access to charging facilities is a prerequisite for large scale deployment for EV. The first component of this dissertation research seeks to formulate a deterministic mixed-integer linear programming (MILP) model to optimize the system of EV charging stations, the locations of the stations and the number of slots to be opened to maximize the profit based on the user-specified cost of opening a station. Despite giving the optimal solution, the drawback of MILP formulation …

Osteoprogenitor Cell Adhesion And Growth On The Bioactive Silicon Nitride Surface For Craniofacial Implants Applications, Kamal Awad

Material Science and Engineering Theses - Archive

As a novel biomaterial, silicon nitride (Si3N4) has been used for orthopedic and spinal fusion applications. Its ability to promote continuity for structural support of missing bone, by in/on bone growth, gives it advantageous properties and potential for mandibular and craniofacial reconstruction applications. Yet, the surface properties of this material and its effect on the osteogenic properties have not been fully realized. Thus, the aim of this study was to evidently investigate the surface properties of the bioactive Si3N4 that enhance the calvarial osteoblasts cell adhesion, growth, and differentiation when compared to conventional implant materials such as titanium (Ti) and …

Nature Inspired Technology: A New Process For Silicification Based On Marine Sponges, Ami Atul Shah

Material Science and Engineering Dissertations - Archive

Silica is used in various industries, ranging from automobile industry for tires to semiconductor industry, paints and coatings, biomedical devices & applications to food & drug industry. The current processing techniques for precipitated silica involve harsh conditions like high temperature and extreme pH conditions. Nature already has highly evolved production techniques for silica. They run at physiological conditions and exhibit intricate control over the synthesis, leading to very pure and ornate siliceous structures. These structures exhibit organized architecture at scales as small as nano-dimensions. The proposed research work is a step, towards development of new techniques that bio-mimic the silica …

Investigation Of The Processing-Structure-Property Relationship In Ta-Si-N Nanocomposite Coatings, Anna Zaman

Material Science and Engineering Dissertations - Archive

The present-day industry demands development of coatings for harsh environmental applications which can resist impact and oxidation at high temperatures. It is vitally important to develop new hard (>30 GPa) protective coatings which will be thermally stable at temperatures, T > 800 °C and simultaneously will ensure a good protection of the substrate against oxidation from an external atmosphere. The limitations of conventional coatings due to inferior hardness or poor oxidation stability can be overcome by nanocomposite coatings as they exhibit enhanced and completely new properties. To address this requirement of new enhanced protective systems, there is a need to …

New Mixture Additives For Sustainable Bituminous Pavements, Gabriel Mukristu Nsengiyumva, Kommidi Santosh, Yong-Rak Kim, Helan Xu, Yiqi Yang

Nebraska Department of Transportation: Research Reports

In an effort to improve mechanical properties of asphalt concrete, an exploratory research using mixture additives was attempted. Two different types of additives on two material scales were used: asphalt concrete (AC) level and binder level. At the start of this study, the effect of natural cornhusk fibers on the resistance of two types of AC mixtures on cracking were tested for hot-mix asphalt (HMA) and cold-mix asphalt (CMA). The results showed slight improvements in cracking resistance in cornhusk reinforced HMA, and in the case of the CMA, marshal flow. Overall, based on the test results, cornhusk-reinforced HMA and CMA …

Optimal Surgical Plating Of Mandibular Angle Fractures: A Validated Finite Element Model, Brett Seeley-Hacker

Wetterhahn Science Symposium Posters 2018

No abstract provided.

Securing Soft Ips Against Hardware Trojan Insertion, Thao Phuong Le

Graduate Theses and Dissertations

Due to the increasing complexity of hardware designs, third-party hardware Intellectual Property (IP) blocks are often incorporated in order to alleviate the burden on hardware designers. However, the prevalence use of third-party IPs has raised security concerns such as Trojans inserted by attackers. Hardware Trojans in these soft IPs are extremely difficult to detect through functional testing and no single detection methodology has been able to completely address this issue. Based on a Register-Transfer Level (RTL) and gate-level soft IP analysis method named Structural Checking, this dissertation presents a hardware Trojan detection methodology and tool by detailing the implementation of …