Engineering Commons^™

City Of Guadalupe Cultural Arts & Education Center Veterans Memorial Wall, Alejandra Arroyo Perez

Construction Management

As a student in Construction Management, the importance of firsthand experience in the construction industry should not be taken lightly. The responsibility of every construction manager is to learn how to take a project from concept to reality. The primary five elements of construction management entail project programming, design development, material specifications, estimating, and scheduling. This paper documents the construction management process related to a Veterans Memorial Wall. Through coordination with the project stakeholders (i.e. property owners, engineer consultants, material fabricators, and vendors) a fully immersive construction management experience is gained. One of the stakeholder requirements was to establish a …

Erratum: Physicochemical Insights Of Irradiation-Enhanced Hydroxyl Radical Generation From Zno Nanoparticles(Toxicology Research Doi: 10.1039/C5tx00384a), Qingbo Yang, Tien Sung Lin, Casey Burton, Sungho Park, Yinfa Ma

Electrical and Computer Engineering Faculty Research & Creative Works

In the originally published version of this manuscript, the fourth author's name is incorrect. The name should read "Sungho Park", instead of "Sung-Ho Park". These details have been corrected only in this corrigendum to preserve the published version of record.

Investigations Into Unintended Esd Generator Artifacts: Prepulse And Postpulse, Jianchi Zhou, Pengyu Wei, Li Shen, Xin Yan, Giorgi Maghlakelidze, Guido Notermans, Sergej Bub, Steffen Holland, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

An electrostatic discharge (ESD) generator may create pre- and post-pulses in addition to the main pulse. These artifacts can cause additional device under test (DUT) failures. The origin and magnitude of these pulses were investigated in four commercial generators using measurements and simulation. Two types of unwanted pulses were identified. One is caused by the reignition of the spark, and the other relates to the relay contacting for charging the main capacitor. These pulses cause strong high-frequency signals, partially surpassing the radio frequency content of the main pulse. The spectrum of the pre- and postpulses varies greatly between different generators. …

An Introductory Study Of Coal Fly Ash Enhancement For Heavy Metal Removal In Wastewater Treatment., Samuel T. Romes

Electronic Theses and Dissertations

Coal Combustion Products are the materials that remain after pulverized coal is burned to generate electricity. The fine portion, fly ash, has many re-use capabilities across various industries. Most recent data shows that approximately 60% of fly ash produced in the United States was used with the largest re-use being concrete additives. This work aims to enhance fly ash via hydrothermal treatment in order to expand the re-use capabilities of the material. These materials were tested as adsorbents for heavy metal removal from wastewater samples. The metals tested for removal were Copper (II) Acetate, Cadmium Chloride, Boric Acid, Sodium Selenite, …

Coal Fly Ash Beneficiation For Reuse And Removal Of Boron, Cadmium, Chromium, Copper, And Selenium In Wastewater Treatment., Joseph E. Cahill

Electronic Theses and Dissertations

New regulations on coal-fired power plants make previously used wastewater treatment methods aimed to remove heavy metals obsolete. Therefore, there has been increased interest and investment into new technologies to treat coal-fired power plants effluent in the past few years. Traditionally, heavy metal removal technologies have been broken into three categories: physical, chemical or biological. However, with new regulations, each category by itself does not offer an ideal solution to removing acceptable concentrations of heavy metals found in the effluents at the coal-fired power plants. Here we report a novel proof-of-concept utilizing adsorption through ion-exchange/co-precipitation - chemical and physical - …

Scalable Synthesis Of Alumina Nanowires By Wet Chemical Method., Luis N Moreno

Electronic Theses and Dissertations

To satisfy an increasing demand for large-scale processes for producing alumina nanomaterials, a wet chemical method was evaluated. A potassium salt precursor was combined with aluminum to produce alumina – based nanowires. Compared with current methods such as thermal oxidation, sol-gel, and laser ablation, this method is highly scalable due to relatively low energy requirements and the ability to carry out the primary reaction under ambient conditions. The nanowire samples were evaluated using SEM, XRD, BET, and TEM to confirm morphology, phases present, and surface area. A porous nanowire structure was confirmed which has a BET surface area of 324.6 …

Update Of Multicellular Data Standard To Match Physicell "Compact" Output., Reid A Honeycutt

Electronic Theses and Dissertations

In the field of multicellular biology, it is currently very difficult for researchers to share digital data, due to a lack of standards for said data. Each laboratory will collect data from a particular project, which will describe only the features relevant to their research, and then present that data using written descriptions, charts, graphs, and images. This makes it difficult for the data produced by these studies be leveraged in other research efforts by scientists studying similar phenomena. An open-source, universal standard that attempts to meet this need is the MultiCellular Data Standard (MultiCellDS). MultiCellDS is described as a …

Design Of A 300cm2 Pemfc Stack With Force And Cfd Simulation To Optimize Flow Channels, Gasket Design, And Clamping Forces., Robert M. Ench

Electronic Theses and Dissertations

Proton exchange membrane fuel cells are important to the future of green energy as hydrogen can be made with green technologies and store energy for later use. Fuel cells can efficiently convert the hydrogen to electricity as needed. This study uses Solidworks simulation to make design improvements to the fuel cell before the prototype build stage of testing; this saves money and time by reducing the prototype builds needed.

In this study, a multi-channel serpentine design with two outlets versus a single outlet is evaluated using CFD to investigate pressure drop. Lower pressure drops are desirable as less energy input …

Solvent Engineering Of Molybdenum Disulfide Electrocatalyst For Hydrogen Evolution., Robert Carl Spalding

Electronic Theses and Dissertations

Energy is at an exponentially growing demand, and to keep up with these demands new technologies for renewable energy have received increased attention. Hydrogen plays a vital role in water electrolysis and fuel cells, as the hydrogen evolution reaction (HER) is the main step water splitting process. Most of the current electrocatalysts for HER are dominated by platinum and other precious metals due to their low over-potential and small Tafel slope, however, they are extremely costly. For this reason, cost-effective non-precious metal catalysts must be developed. Transition metal dichalcogenides, such as molybdenum disulfide (MoS2), are abundant and have recently shown …

Computational Modeling Of 3d-Printed Lactobacillus-Antibiotic Scaffolds For Bacterial Vaginosis., Veeresh P. Rai

Electronic Theses and Dissertations

The standard treatment for bacterial vaginosis (BV) is currently antibiotics, such as metronidazole, clindamycin, or tinidazole. These antibiotics are highly effective in getting rid of bacteria in the female reproductive tract (FRT); however, there are some bacteria that provide benefits to the FRT which also get expunged. While there are many strains of bacteria that play a beneficial role in the FRT, lactobacilli are among the most important. These bacteria are responsible for maintaining a healthy environment in the FRT via pH regulation by lactic acid metabolism. Antibiotics eliminate all bacteria from an environment, including lactobacilli, and as a result, …

Evolutionary Algorithms For Function Model Synthesis, Amaninder Singh Gill

Theses and Dissertations

Function modelling plays an essential role in the systematic design process. Designers are trained in the academia trained on function models, yet the acceptance of function models in the industry remains sparse. A possible reason is that there is a lack of computational support for synthesizing function models. The research presented in this dissertation aims to fill that gap. A conceptual proof of function model synthesis using a Genetic Algorithm (GA) is initially presented. Thereafter a priori rules to evaluate function model have been developed. These rules do not rely on a designer conveying designer intent to the algorithm, which …

Thermoelectric-Based Cooling Systems For Building Application: A Sustainable Solution, Seyedehmohadeseh Seyednezhad

Theses and Dissertations

In the United States, buildings account for a large share of the annual energy consumption, nearly 40%. Fossil fuels including coal, oil, and natural gas account for the main source of electric power generation and constitute the largest portion of the building energy consumption. Such a high level of fossil fuel consumption is a multifaceted challenge as demand for energy grows, and natural resources become scarce and expensive, while the climatic effects of massive energy use will be clearly felt by all. As a necessary component for occupants’ thermal comfort, cooling and air conditioning systems are among the largest energy …

Feasibility Analysis And Performance Study Of A Pulsed Solid Propellant Integrated Propulsion System For Small Satellites, Tahir Kanchwala

Theses and Dissertations

Solid propellant has come a long way since the 13th century when gunpowder was widely used as the go-to means in rocket propulsion. Of course, back then, rockets were not intended to carry humanity out of the atmosphere. Untill the introduction of liquid propellants in the mid-20th century, solid propellants were the foundation. Still, liquid propellants aimed to add more stability and controllability to rocketry and thus were preferred over their solid counterparts. This thesis seeks to analyze a novel type of propulsive device that aims to eliminate challenges faced by both types of fuels and instead utilize the advantages …

Socio-Economic Variables And Their Relationships With The Passenger To Population Ratio, Jack Matthew Westbury

Theses and Dissertations

As the aviation industry expands and becomes commonplace in the modern world, it would behoove us to understand how the industry develops and passenger to population ratio could be a measure of that development. If called upon to identify how the aviation industry develops, one could only make suggestions as to which variables might be key in the development of the aviation industry. This study used existing socio-economic and population data from the United Nations and passenger information from the International Air Transport Association, with the aim to deepen the understanding of the relationship between socio-economic variables and the passenger …

Developing A Prototype Energy Harvesting Device For Powering Wireless Onboard Condition Monitoring Sensor Modules For Railway Service, Martin Amaro Jr.

Theses and Dissertations

An energy harvesting system is being developed to power a wireless bearing health monitoring device. In contrast to other monitoring systems, this wireless monitoring device is a low-powered onboard solution. Powered by a 3.7-Volt lithium-ion battery, the device can continuously function for several months on a single charge. By implementing an energy harvesting system, the life of the battery can be increased reducing the overall maintenance, electronic waste, and time needed to replace the batteries. The harvesting system uses thermoelectric generators to convert the heat generated in the bearings into electricity. The system is composed of aluminum heat sinks, a …

To A More Sustainable Construction Method For Electrically Conductive Heated Pavement Systems, Mohammad Anis

Theses and Dissertations

Snow and ice damage to the pavement in the United States, particularly in colder regions, costs the US economy millions of dollars each year. Conventional methods for keeping snow off roads after heavy snowfall are judged prohibitively expensive. As a result, an alternative solution is required to reduce costs while also improving pavement resiliency. An electrically heated pavement system (EHPS) has been regarded as a viable alternative to older approaches in recent years. The majority of earlier research concentrated on improving the conductivity characteristics of paving materials. On the other hand, this study takes a different approach by focusing on …

The Skeletal Structure Of Hot Mix Asphalt And The Effects Of Fiber Additives, Samantha A. Avila

Theses and Dissertations

Hot mix asphalt (HMA) has proven to be successful in providing a proper paving surface for transportation services throughout the world. Asphalt pavement could be altered as the gradation of the mixture is adjusted. For instance, mixtures could vary from Dense Graded (DG) that contain a fairly even percentage of all aggregate size allowing for a more compact fit to Stone Matrix Asphalt (SMA) where the coarse aggregate compromise the main skeleton while fine aggregate fills the voids. This study investigates the effects of fibers and skeletal structures on mechanical properties of HMA. Two types of fiber additives are tested …

Synthesis And Characterization Of Copper Oxide Nanofibers, Shishir Barai

Theses and Dissertations

The aim of this study was to develop polymer-derived Copper (II) Oxide (CuO) nanofibers through centrifugal spinning technique and subsequent calcining. To obtain the force spun pre-ceramic copper acetate nanofibers, 15% wt, 25% wt, 35% wt, 50% wt% copper acetate (active material) and poly (vinyl) alcohol ( PVA) solutions was prepared with deionized water (DI) as solvent and spun at 7500 rpm in a FibeRio Cyclone. Thermogravimetric analysis (TGA) was implemented to determine the thermal degradation behavior of the pre-ceramic nanofibers. These nanofibers were then calcined at three different temperatures (500, 600 and 700°C) to produce CuO nanofibers. The microstructure, …

Lubrication Performance Of Vegetable Oils Modified With Halloysite Clay Nanotubes (Hnt) As Lubricant Additives, Md Abu Sayeed Biswas

Theses and Dissertations

Vegetable oil-based nano-lubricants are a great alternative to petroleum-based lubricants because of their less adverse impact on the environment. This work evaluates the tribological performance of sunflower, corn, and peanut oils modified with halloysite clay nanotubes (Al2Si2O2(OH)2nH2O) as lubricant additives at different concentrations. To analyze the tribological performance of the nano-lubricants, a block-on-ring tribometer was used following the ASTM G-077-17 standard procedure. Characterization of HNT was carried out by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA). The effect of the HNT on the lubrication performance of the newly developed vegetable oil-based nano-lubricants was evaluated, and the …

Assessing The Effectiveness And Efficacy Of Wireless Onboard Condition Monitoring Modules In Identifying Defects In Railroad Rolling Stock, Lee R. Cantu

Theses and Dissertations

Many industries have begun shifting into the Internet of Things (IoT) in the 21st century. To help ease this transition for the rail industry, The University Transportation Center for Railway Safety (UTCRS) has partnered with Hum Industrial Technology, Inc. (HUM) to help complete the development of a Wireless Onboard Condition Monitoring system named the ‘Boomerang™’. This product allows customers to schedule proactive maintenance on their railcars to replace defective wheels and/or bearings, saving them time, money and potentially preventing costly catastrophic derailments. The UTCRS research team has established thresholds to determine defective bearings utilizing thermal and mechanical sensors.

The effectiveness …

Molecular Dynamics Study Of Atomic Diffusion In Cantor High Entropy Alloy In The Selective Laser Melting Process, Mathew Z. Farias

Theses and Dissertations

High entropy alloys (HEAs) are compositionally complex alloys that are comprised of 5 or more principle elements at near equimolar concentrations. The Selective Laser Melting (SLM) method generally melts pure elemental powders or prefabricated alloy powders, this process allows for the production of heterogeneous structures that would be difficult to create through more conventional means. In-situ alloying in SLM, or Laser Additive Alloying (LAA), using pure elemental powders is a promising means of producing what would otherwise be costly and difficult to fabricate products with less defects using prefabricated powders, therefore this new approach could enable the ability to …

Life-Cycle Cost Analysis Of The Efficient Water Fixtures And Electric Appliances Used To Minimize Water And Energy Consumption In Homes In The U.S, Miranda N. Garcia

Theses and Dissertations

Consumer interest in incorporating sustainability and efficient appliances into daily life has been growing in the past several years. While reducing their environmental impact may be a draw to some, by making the switch to water- and energy-efficient appliances many homeowners are enticed by the promise of long-term savings on utility bills. Programs such as WaterSense and Energy Star not only offer certified efficient appliances and fixtures, but they may also certify water- and energy-efficient homes. Additionally, the United States Green Building Council (USGBC) offers the LEED program (Leadership in Energy and Environmental Design) which certifies homes in a similar …

A Gis-Based Model To Assess On-Site Sewage Facility (Ossf) Contamination Risk To Local Water Resources, Alvaro Garcia

Theses and Dissertations

In a collaborative effort between Texas Water Resources Institute (TWRI), Cameron County Public Health (CCPH), Texas A&M AgriLife Extension (TAMAE), and the University of Texas Rio Grande Valley (UTRGV), a GIS database that includes relevant OSSF information, such as location, system age, lot size, and other important parameters was created.

This OSSF database, along with publicly available GIS data, was used to create an integrative GIS-based risk assessment model where OSSF risk parameters were assigned a risk factor and combined into a spatial contamination risk for surrounding areas and their receiving waterbodies. Parameters were broken down into two categories: environmental …

Synthesis And Characterization Of Centrifugally Spun Molybdenum-Based Nanomaterials For Lithium-Ion Batteries, Ramiro Gonzalez Jr.

Theses and Dissertations

The work presented in this thesis focuses on the processing and development of transition metal compound composite fibers as anode materials for rechargeable lithium-ion batteries (LIBs). Among the transition metal compounds, molybdenum compounds have risen as promising candidates of advanced electrode materials, in view of their natural abundance, virtuous mechanical/thermal stability, rich chemistry, high theoretical specific capacity, and multiple oxidation states of Mo. The current work reports synthesize MoO2/C and MoO3/C composite fibers drawn from centrifugal spun ammonium molybdate/PAN precursor fibers, followed by a thermal treatment stabilizing in air and calcination under argon atmosphere. The weight ratios of (MoOx, 2 …

Development Of A Compact Core Flooding Apparatus For Matrix Acidizing Applications, Antonio Hernandez Zuniga

Theses and Dissertations

Matrix Acidizing is defined as a well stimulation technique in which the acid is injected into the formation with the purpose of dissolving the minerals present and thus enhancing the permeability of the formation and facilitating the extraction of oil and/or gas from the formation. The primary goal of acid diversion is the creation of wormholes and ramification paths that allow the fluid to flow from the higher to the lower permeability zones of the limestones, sandstones or carbonate reservoirs. Naturally, as the injected acid will follow vugs, fractures and pores, HCl is used because of its quick reaction and …

Data Analytics For Google Trend Search Result Of Illness Symptoms, Md Jakir Hossain

Theses and Dissertations

The outbreak of COVID-19 has escalated from March 2020. Since then, people from all over the world are curiously searching different types of illness symptoms including corona virus. Before the outbreak, people were also searching different types of symptoms at different times. Both diseases share same symptoms, but in the flu season. If certain types of symptoms are visible at summer season, then these symptoms are for corona virus. The main purpose of our study is to find out this discriminative information from these search result. We will discuss some mathematical concepts and then develop an algorithm based on those …

Characteristics Analysis Of Electrochemical Impedance Spectroscopy (Eis) For Different Electrode Patterns, Shanzida Kabir

Theses and Dissertations

Electrochemical impedance spectroscopy (EIS) is a rapidly developing technique used in characterizing materials and interfaces. Using equivalent circuits as models can determine the electrical properties of heterogeneous systems like membranes or electrolytes. Different electrochemical processes like the electron transfer rate of a specific reaction or the capacitive behavior of the system, or even the diffusion-limited response can coincide. EIS is applicable to determine different electrochemical processes that can happen simultaneously. The purpose of this research is to find the optimal operating range for other AC electrokinetic mechanisms. Analysis of EIS can be helpful in both fundamental examinations of electrokinetic transport …

Selective Laser Melting Of Titanium Diboride: A Study Of The Energy Density Effects, Lazaro Lopez Mendez

Theses and Dissertations

Natural titanium diboride (TiB2) has been reported the 5th hardest material on earth. Due to its superior properties, such as high density, high elastic modulus, and high compressive strength, TiB2 becomes one of the most suitable ceramic reinforcements for applications with severe friction and heavy loading conditions. This study is intended to produce TiB2 using 3D additive manufacture (AM) technology, and then to understand the tribological property of the AM fabricated TiB2 specimens. In this study, a laser additive alloying (LAA) process was developed based on a Renishaw AM laser system. One mm thick samples were prepared using the LAA …

Development Of Vegetable Oil-Based Nano-Lubricants Using Montmorillonite Clay (Mmt) Nanoparticles As Lubricant Additives, Md Mashfiqur Rahman

Theses and Dissertations

Because of the environmental impact and price volatility, there has been a growing concern on the use of petroleum-based lubricants. This issue has stimulated research into the development of biodegradable lubricants like vegetable oils. In this study, the tribological and rheological behavior of sunflower, peanut, and corn oils modified with Montmorillonite nanoclay (MMT) as lubricant additives were evaluated at various concentrations. A custom-made block on ring tribotester was used to evaluate the wear and friction characteristics of the nano-lubricants, following the ASTM G-077-05 standard. The effects of concentration and shear rate on shear viscosity were studied using a parallel plate …

High Performance Electromagnetic Interference Shielding From Lightweight-Flexible Polymer Composite Fiber Structures, Fariha Rubaiya

Theses and Dissertations

This study focuses on the development and characterization of fiber-based polymer composite structures with the goal of developing high performance, flexible, lightweight, and cost-effective materials for electromagnetic interference shielding and piezoelectricity. Polyvinylidene fluoride (PVDF) was used as the base fiber mat while polyaniline (PANI), polypyrrole (PPY), polyindole (PIN), polydiacetylene (PDA) and Zn2GeO4 (ZGO) were incorporated via solution mixing and in-situ polymerization. The PVDF fine fiber systems were produced using the Forcespinning® method. Morphology, structure, thermal stability, electrical properties, EMI shielding effectiveness and piezoelectric performance of the fiber mats were analyzed. The composite system containing 1.25 wt. % of ZGO-PVDF displayed …