Engineering Commons^™

Neurotoxicity Of Asimina Triloba, Myriam Sanders

Honors Theses

Neurodegenerative diseases are thought to be brought on by genetic and environmental factors including exposure to compounds and extracts found in plants. Many substances extracted from plants have been shown to induce cell death in neurons. This experiment tests different plant compounds to determine if they induce death in neurons in cell culture. In particular, we focused on extracts and compound from the Asimina Triloba plant- a plant that had anecdotally been connected with Parkinson's Disease-like effects. Cultured neurons were treated with increasing concentrations of the compounds and extracts. Twenty-four hours after treatment, viability was assessed. Results show that while …

Shale Characterization And Size-Effect Study Using Scanning Electron Microscopy And X-Ray Diffraction, Debashis Das

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ground failure is a major contributor of the total fatalities in underground mines in the US. Underground coal mines in the Northern Appalachian region have weak roof rock mainly composed of shale and sandstone. Characterization of shale is indispensable for developing an effective ground control plan. However, this has not been done extensively. This thesis attempts to address this issue. It investigates the variation in mechanical properties of shale with variation in size. In addition, an attempt has been made to relate the strength of shale with its petrographic parameters. X-ray diffraction technique was used to estimate the compositional parameters …

An Origami-Based Thickness-Accommodating Bistable Mechanism In Monolithic Thick-Sheet Materials, Larry L. Howell, Spencer P. Magleby, Nathan A. Pehrson

Faculty Publications

Origami-based mechanisms can provide useful capabilities in folding large structures to stow in small volumes. However, when using monolithic thick-sheet materials for these types of mechanisms, accommodating the thickness proves challenging. One approach to solve this is to create compliant mechanisms along the fold lines that inherently store energy when actuated and causes the mechanism to tend toward its low energy state. This tendency can be used to create bistable states. We outline a method to use this stored energy to achieve bistable states and name the resulting mechanism an origami-based “Thickness-accommodating bistable interior vertex” (TABIV) in monolithic thick-sheet materials. …

Deployable Lenticular Stiffeners For Origami-Inspired Mechanisms, Larry L. Howell, Alden D. Yellowstone

Faculty Publications

Light-weight origami-inspired mechanisms can provide advantages in deployable space systems and other applications. However, a significant challenge in their design is ensuring that they are sufficiently stiff. Compliant, deployable stiffeners utilizing a profile approximating the Euler Spiral are proposed as one solution. Structures with this profile, called a lenticular stiffener, are shown to permit stiffeners to flatten using forces applied at their edges. Formulas for calculating the stiffness increase are developed. Relations needed to design the deployment behavior of the stiffeners are also derived. Finally, advantages of different stiffener configurations are evaluated. These results are verified through simulation and experiments.

Kinematic/Static Model Of Complex Compliant Mechanisms With Serial-Parallel Substructures: A General Approach, Larry L. Howell, Mingxiang Ling, Junyi Cao

Faculty Publications

Kinematic and static analyses of compliant mechanisms are crucial at the early stage of design, and it can be difficult and laborsome for complex configurations with distributed compliance. In this paper, a general and concise kinematic/static modeling method of flexure-hinge-based compliant mechanisms with arbitrary serial-parallel substructures is presented to provide accurate and efficient solutions by combining the matrix displacement method with the transfer matrix method. The transition between the elemental stiffness matrix and the transfer matrix of the flexure hinge and the flexible beam is straightforward, enabling the condensation of a hybrid serial-parallel substructure into one equivalent element simple. Then, …

Instrumentation And Inertial Navigation Systems Design For Tensegrity Robot Implementations, Scott Edward Harper

Graduate Theses, Dissertations, and Problem Reports (ETD)

One of the major challenges faced when developing missions for the exploration of planetary bodies is the risk these terrains pose on the science platform when using a traditional lander or wheeled rover. One means of developing platforms to traverse these harsh terrains is to utilize mobility systems comprised of tensegrity structures. These structures have the capacity to distribute loads across a network of axially loaded members such that they can be constructed in a very lightweight manner and morph their geometries when required. In literature, there has been significant progress in simulated environments to utilize tensegrity structures as mobility …

Explanatory And Causality Analysis In Software Engineering, Yasser Ali Alshehri

Graduate Theses, Dissertations, and Problem Reports (ETD)

Software fault proneness and software development efforts are two key areas of software engineering. Improving them will significantly reduce the cost and promote good planning and practice in developing and managing software projects. Traditionally, studies of software fault proneness and software development efforts were focused on analysis and prediction, which can help to answer questions like `when’ and `where’. The focus of this dissertation is on explanatory and causality studies that address questions like `why’ and `how’.

First, we applied a case-control study to explain software fault proneness. We found that Bugfixes (Prerelease bugs), Developers, Code Churn, and Age of …

Resilience Modeling Of Surface Transportation System In Mixed Traffic Environment, Shofiq Ahmed

Graduate Theses, Dissertations, and Problem Reports (ETD)

Large-scale natural disasters challenge the resilience of surface transportation system. The objective of this research was to develop a resilience model of surface transportation system in mixed-traffic environment considering varying Connected and Automated Vehicle (CAV) penetration scenarios. As deployment of CAVs are expected to improve traffic operations, a resilience model was developed in this research to evaluate the resilience performance of a transportation system with several CAV penetration levels (0%, 25%, 50%, 75% and 100%) for a given budget and recovery time. The proposed resilience quantification model was applied on a roadway network considering several disaster scenarios. The network capacity …

Application Of Machine Learning On Fracture Interference, Dennis Wayne Chamberlain Jr.

Graduate Theses, Dissertations, and Problem Reports (ETD)

A method has been developed that locates and determines well-to-well hydraulic fracture interference (frac-hit) in shale plays using hard data. This method uses Artificial Neural Networks (ANN) with designated parameters and target outputs in conjunction with graphs of gas flowrate, tubing pressure, and cumulative gas prediction. The method was created to address the significant increase in frac-hit occurrences due to the infill wells being completed in shale plays. The production data of the well is first cleaned to eliminate outliers in the initial timeframe of the well and periods of no production so that the ANN model can be accurately …

Automated Cleaning Of Identity Label Noise In A Large-Scale Face Dataset Using A Face Image Quality Control, Mohamad Al Jazaery

Graduate Theses, Dissertations, and Problem Reports (ETD)

For face recognition, some very large-scale datasets are publicly available in recent years which are usually collected from the internet using search engines, and thus have many faces with wrong identity labels (outliers). Additionally, the face images in these datasets have different qualities. Since the low quality face images are hard to identify, current automated identity label cleaning methods are not able to detect the identity label error in the low quality faces. Therefore, we propose a novel approach for cleaning the identity label error more low quality faces. Our face identity labels cleaned by our method can train better …

Development Of Oxide-Dispersion-Strengthened Nickel-Based Super Alloy Powders For Additive Manufacturing, Sizhe Huang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Oxide-Dispersion-Strengthened (ODS) Nickel-Based superalloy has been drawn a huge attention and developed with good oxidation resistance, corrosion resistance and high creep strength. It has been considered as critical materials for Additive Manufacturing (AM). The quality and the efficiency of fabrication methods of ODS limits the performance of itself on AM. The development of new type of ODS, new methodologies and evaluation techniques are required if the enhanced quality of ODS and enhanced efficiency of fabrication are to be achieved. Of the current fabrication techniques for AM, Gas Atomization (GA) is widely used since they can generate spherical powders with high …

An Experimental Investigation Of The Cooling System For A Free Piston Stirling Engine, Akshay Milind Gupte

Graduate Theses, Dissertations, and Problem Reports (ETD)

Free-Piston Stirling Engine (FPSE) has been identified as a good candidate for combined heat and power application (CHP). FPSE being highly efficient and environmentally friendly promises to facilitate the increasing demand in waste heat energy recovery systems. FPSE system consists of three important components: (1) hot side heat exchanger; (2) regenerator; and (3) cold side heat exchanger. The cold side heat exchanger is a crucial part as it enables to maintain an optimal temperature of the working fluid by rejecting heat.

This research contributes to the design of heat exchanger test rig and experimental measurement of cooling heat exchanger. The …

Experimental Design, Testing, And Evaluation Of Methods To Improve The Efficiency And Reduce Emissions From A Small Two-Stroke Natural Gas Engine, Christopher Joseph Ulishney

Graduate Theses, Dissertations, and Problem Reports (ETD)

Decentralized power generation is a research area of interest due to possible improvements in electrical generation efficiency and grid resilience. Two-stroke engines are simple, inexpensive, power dense systems that could serve as the prime-movers for combined heat and power (CHP) systems. In addition, such systems could be fueled on natural gas (NG) that is readily available to serve as a reliable fuel source in most households. However, most two-stroke engines are inefficient and produce excessive emissions. This research focused on methods to simultaneously improve engine efficiency and decrease emissions from a 34 cc air-cooled, two-stroke engine retrofitted to operate on …

Design And Evaluation Of Novel Attitude Estimation System Using Mems Sensors For Indoor Uas, Joshua Bruce Milam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Most small unmanned aerial systems in use today, employ extended Kalman filter sensor fusion algorithms in order to provide accurate estimations of attitude or orientation. These complex algorithms use measurements from GPS receivers and magnetometer sensors that can be rendered useless in GPS denied environments or areas of significant magnetic interference, such as inside buildings or other structures. The complexity of these algorithms makes them inaccessible for some researchers and hobbyists who wish to code their own attitude estimation algorithms. This complexity is also computationally expensive and requires processors that are powerful enough to operate the algorithms along with any …

Investigation Of Combustion Characteristics Of A Heavy-Duty Diesel Engine Retrofitted To Natural Gas Spark Ignition Operation, Jinlong Liu

Graduate Theses, Dissertations, and Problem Reports (ETD)

The conversion of existing diesel engines to natural-gas spark ignition operation by adding a gas injector in the intake manifold for fuel delivery and replacing the diesel fuel injector with a spark plug to initiate and control the combustion process can reduce U.S. dependence on petroleum imports and curtail engine-out emissions. As the conventional diesel combustion chamber (i.e., flat head and bowl-in-piston) creates high turbulence, the engine can operate leaner, which would increase its efficiency and reduce emissions. However, natural gas combustion in such retrofitted engines presents differences compared to that in conventional spark ignited engines. Subsequently, the main goal …

Applications Of Cellular Components In Engineered Environments, Xiao Hu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Manipulation of cellular components in synthetic environment has attracted interest for applications ranging from sensors to nanelectronics and from catalysis to biomedical devices. In such applications, biological-based processes such as specific recognition and self-assembly direct the formation of hierarchical structures, all at minimum energetic costs, with high efficiency and reliability.

Among such cellular machines, microtubules and kinesins have attracted special interest. Inside the cells, microtubules are giving structural integrity while serving as regular and uniform tracks for transport of vesicles or organelles. Kinesin uses a microtubule track in vivo to progress to specific locations with processive and coordinated steps, all …

Differentiating Human Populations Based On K-Mer Classification Of Hand Bacteria, Thrisha Doppala

Graduate Theses, Dissertations, and Problem Reports (ETD)

Bacterial communities found in and on the human body are not only used in studying human health conditions but are also effective in differentiating individuals due to their distinct profiles. Human palm regions harbor relatively more diverse bacterial communities and are indicative of population groups, life styles, geographic locations, age groups and health conditions. Sequences extracted from hypervariable region V3 of the 16S rRNA bacterial gene of hand bacterial samples from 9 different population groups were classified into Operational Taxonomic Units (OTU) with GreenGenes reference taxonomy using RDP (Ribosomal Database Project) classifier. Frequencies of identified OTUs were used to study …

Parametric Study Of Coal Liberation Behavior Using Silica Grinding Media, Adewale Wasiu Adeniji

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study evaluates the coal liberation behavior using silica as the grinding media by assessing the effects of four operating factors including nominal feed size, media size, shaft speed and grinding time, each of three levels on two response variables, the product P₈₀ and the specific energy. The coal material used in this study was mixed-phase particles commonly referred to as middlings, sampled from dense medium circuit at the Leatherwood preparation plant in Kentucky. One-third fractional factorial design of resolution III was implemented. Since silica was obtained in three standard size ranges as per manufacturer’s design, media size was …

Detection Of Buried Non-Metallic (Plastic And Frp Composite) Pipes Using Gpr And Irt, Jonas Kavi

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research investigated alternative strategies for making buried non-metallic pipes (CFRP, GFRP, and PVC) easily locatable using Ground Penetrating Radar (GPR). Pipe diameters up to 12" and buried with up to 4 ft. of soil cover were investigated. The findings of this study will help address the detection problem of non-metallic pipelines and speed the adoption of composite pipes by the petroleum and natural gas industry. The research also investigated the possibility of locating buried pipes transporting hot fluids using Infrared Thermography (IRT).

Results from the study have shown that, using carbon fabric and aluminum tape overlay on non‑metallic pipes …

Modeling And Evaluation Of A Ridesharing Matching System From Multi-Stakeholders' Perspective, Md Tawhidur Rahman

Graduate Theses, Dissertations, and Problem Reports (ETD)

With increasing travel demand and mobility service quality expectations, demand responsive innovative services continue to emerge. Ridesharing is an established, yet evolving, mobility option that can provide more customized, reliable shared service without any new investment in the transportation infrastructure. To maximize the benefits of ridesharing service, efficient matching and distribution of riders among available drivers can provide a reliable mobility option under most operating conditions. Service efficiency of ridesharing depends on the system performance (e.g., trip travel time, trip delay, trip distance, detour distance, and trip satisfaction) acceptable to diverse mobility stakeholders (e.g., riders, drivers, ridesharing operators, and transportation …

Characteristics Of Activated Carbons Produced From Herbaceous Biomass Feedstock, Oluwatosin Jerry Oginni

Graduate Theses, Dissertations, and Problem Reports (ETD)

Energy security and environmental protection are at the forefront of research due to the forecasted depletion of fossil fuel reserves and the growing concern of its adverse environmental impacts. The use of renewable sources for energy applications has centered on the use of biomass feedstocks and this include from herbaceous, woody, agricultural waste, forest residues and municipal wastes. The thermochemical conversion (pyrolysis) of these biomass feedstocks has potential to produce liquid fuel, a solid residue (biochar) and non-condensable gas. The biochar is primarily composed of renewable porous carbon and other inorganic compounds. The biochar is used for soil amendment, adsorption …

The Nakahara Effect And Its Influence On Solution-Based 3d Printed Films, Daryl Kwakye-Ackah

Graduate Theses, Dissertations, and Problem Reports (ETD)

Motivated by the Nakahara Effect, the influence of altering printing parameters on fragmentation mechanism(s) of directly written titanium dioxide(TiO₂) films is investigated. The Nakahara effect states that a long lasting memory can be introduced into a colloidal system prior to drying, affecting the type of crack pattern formed due to externally applied forces. TiO₂ has important applications due to its interesting semiconducting properties, tunable band gap, photocatalytic properties, biocompatibility, and relative abundance. This is the reason it is used in this project as a model printing ink system.

In this research, two deposition methods (i.e. direct-ink writing …

Roofing Practices And Fall Prevention In The Construction Industry, Hadi A. Shishtar

Graduate Theses, Dissertations, and Problem Reports (ETD)

Roofing is an important profession in the construction industry yet there is a lack of understanding of its safeness. It is generally believed that roofing is an occupation that can be easily practiced by anyone. However, there are many key factors that are associated with roofing, which may impact the lives of roofers who often face major risks at work. According to the Occupational Safety and Health Administration (OSHA), roofing is one of the leading causes of falling deaths among construction workers. The Bureau of labor statistics has reported that roofers are highly exposed to non-fatal injuries. They have also …

Remotely Sensed Hydroclimatic Variability For Water Security In An Agricultural Basin, Ashish Kondal

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Indus Basin has supported agricultural practices since the Harappan civilization (3000-1500 BC). Abundance of water has always supported agriculture in the region and built the Indus Basin as one of the major agriculture based economies of the world. The obvious dependency of agriculture on weather and the vagaries of climate emphasizes the necessity of a comprehensive hydro-climate study of the region. The role of climate change in the Indus Basin has always been a contentious issue. Groundwater depletion is evident in the region, and its steady and alarmingly declining rate has brought concerns for the future of agriculture in …

The Determination Of The Concrete Tensile Creep At Early Age Using The Ring Test, Tadamon Mohammed

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, the modified double power law (MDPL) model is used to determine the tensile creep of concrete at an early age based on the ASTM C1581 restrained shrinkage ring test. Three concrete mixes using Ordinary Portland Cement (OPC) were tested. The three concrete mixes were cast, and each underwent the ring tests up to cracking. Mechanical properties of concrete at the age of 1, 3, 7, 14, and 28 days were tested to find the compressive strength, tensile strength and Young’s Modulus of concrete. The strength tests results were obtained from both 4x8 inch and 6x12 inch cylinders. …

Using Artificial Intelligence And Machine Learning To Develop Synthetic Well Logs, Marwan Mohammed Alnuaimi

Graduate Theses, Dissertations, and Problem Reports (ETD)

There has been an increase in the need for energy in the recent past. Oil and gas stand as the source of energy that are widely used. The oil and gas reservoirs are targeted for the purposes of field development. The conventional methods of reservoir characteristics require computing techniques that are unique and complex, some of which are labor and time intensive. Mohaghegh argues that all efforts must be tried and made possible to apply Petroleum Data analytics in production and management of reservoir so as to earn a maximum return (Mohaghegh, Shale Analytics, 2017). Different methodologies have been applied …

Design And Optimization Of A 1 Kw Stirling Engine, Garrett Tyler Rinker

Graduate Theses, Dissertations, and Problem Reports (ETD)

Stirling engines are often overlooked as a means of energy conversion, though its versatility offers many advantages. Since it is an external combustion engine, it can be supplied with heat through the combustion of a variety of fuels. Its maintenance- and degradation-free aspects, as well as its excellent turn down ratio, make it a suitable candidate for applications such as remote power generation, combined heat and power (CHP), cryogenics, solar power, and even space exploration. The continual advancement of additive manufacturing (AM) offers opportunity to potentially further improve the already efficient Stirling cycle. This dissertation presents the design and optimization …

Distributed Electric Propulsion Effects On Traditional Aircraft Through Multidisciplinary Optimization, Kevin Moore, Andrew Ning

Faculty Publications

Electric aircraft face a steep tradeoff between the demand for runway performance and range. While fuel based propulsion technologies typically increase in specific power with increasing size, electric propulsion is typically much more scalable. This system scalability enables alternative designs including distributed propulsion, optionally powered propulsion units, and vectored thrust, which can all contribute to better runway performance and range. In this paper, we explore how continuously powered distributed propulsion can reduce takeoff distance while still satisfying range constraints. We use a combination of a blade element momentum method, a vortex lattice method, experimental data, and nonlinear optimization techniques to …

Benefits Of Two Turbine Rotor Diameters And Hub Heights In The Same Wind Farm, Andrew Pj Stanley, Andrew Ning, Katherine Dykes

Faculty Publications

Significant turbine-wake interactions greatly reduce power output in a wind farm. If different turbine hub heights and rotor diameters are included in the same wind farm, the wake interference in the farm will be reduced, resulting in a lower cost of energy (COE) than a farm with identical turbines. In this paper, we present a method to model wind farm COE in farms with hub heights and rotor diameters that vary across the wind farm. We also demonstrate how to optimize these wind farms to minimize COE. The results show that COE can be greatly reduced in wind farms with …

Characterization Of Directionally Solidified Cast Iron, Subhojit Chakraborty

All ETDs from UAB

Cast iron solidifies with various morphologies of the graphite phase, which directly influences its mechanical behavior. Hence, it is crucial to control the graphite morphol- ogy in order to tailor the properties of the iron to specific applications. This makes it crucial to understand the effect of solidification velocity and composition, the two main factors affecting graphite morphology. To study the influence of velocity and composi- tion, particularly nodularizing elements (Mg) and cerium (Ce), a number of batches of iron were produced. The majority of analysis was conducted on those batches where the carbon equivalent was very close to the …