Engineering Commons^™

Multi-Objective Optimization Of A Ridesharing System Performance, Mohammad Nasr Azadani

Graduate Theses, Dissertations, and Problem Reports

Ridesharing is a shared vehicle service with the potential to meet the growing travel demand due to population increase, economic growth, and shortage in transportation infrastructure capacity. Compared to the current system of predominantly using personal vehicles, ridesharing services reduce the number of vehicles while providing mobility services to the same number of people with no additional investment in the transportation infrastructure. One of the big challenges in implementing ridesharing services is matching drivers and riders. Conflicts between matching-objectives to comply with the interests of diverse stakeholders influence the efficiency of ridesharing in a transportation system. This study investigates the …

Effect Of Binder Modification And Aggregate Size On Modulus And Fatigue Of Asphalt Concrete, Elizabeth Bashiti

Graduate Theses, Dissertations, and Problem Reports

Asphalt concrete is one of the main ingredients used in the paving of roadways across the globe. These roadways have been deteriorating from overuse, under design, and a lack of understanding of the engineering properties. In the asphalt community, it is agreed upon that polymer modifiers and aggregate size have comparable impacts on the performance of a pavement, such as, low creep at high temperatures, high ductility at low temperatures, high toughness, resistance to moisture and temperature, high cohesive and adhesive strength. With all of these advantages, it has been often assumed that polymer modifiers extend/improve the expected life of …

Scaling-Based Robust Predictions Of Periodic Stream Water Quality Variables Across The Contiguous U.S., Mohammad Abu Zafer Siddik

Graduate Theses, Dissertations, and Problem Reports

Stream water quality is at the core of the biological and ecological health of streams and rivers. Subject to the environmental variation and in-stream metabolic activities, key water quality indicators such as dissolved oxygen (DO), water temperature (Tw), and chlorophyll a (Chl a, an indicator of primary productivity) typically follow a concave-shaped diurnal cycle. Variation and changes in climatic drivers (e.g., solar radiation, air temperature, and pressure), land uses, and hydrologic variables lead to a high spatiotemporal variability in stream water quality. The spatiotemporal variation challenges the development of robust models for predictions across large scales (e.g., county, state, country), …

Review Of Modern Nondestructive Testing Techniques For Civil Infrastructure, Shabnam Khanal

Graduate Theses, Dissertations, and Problem Reports

The repair and maintenance of aging infrastructures, in the United States alone, are estimated to have backlogs of trillions of dollars. This has posed widespread concerns about the existing and proposed infrastructures to adequately sustain the quality of life in the near future. Efficient and cost-effective approaches, such as nondestructive testing (NDT), are therefore required to better shape our future. Various NDT techniques have been developed over the past two decades with cutting-edge advances towards investigation and condition assessment of civil infrastructures. While the performance of NDT techniques has reached unparalleled heights, limitations remain. On one side, are the instrument …

Integrated Techno-Economic And Life Cycle Analyses Of Biomass Utilization For Value-Added Bioproducts In The Northeastern United States, Yuxi Wang

Graduate Theses, Dissertations, and Problem Reports

A multi-stage spatial analysis was first conducted to select locations for lignocellulosic biomass-based bioproduct facility, using Geographical Information System (GIS) spatial analysis, multi-criteria analysis ranking algorithm, and social-economic assessment. A case study was developed to determine locations for lignocellulosic biorefineries using feedstocks including forest residue biomass and three energy crops for 13 states in the northeastern United States. In the entire study area, 11.1% of the counties are high-suitable, 48.8% are medium-suitable for biorefinery siting locations. A non-parametric analysis of cross-group surveys showed that preferences on biorefinery siting are homogeneous for experts in academia and industry groups, but people in …

Study On The Thermal Properties Of Concrete Containing Ground Granulated Blast Furnace Slag, Fly Ash And Steel Reinforcement, Bekir Erdem Bas

Graduate Theses, Dissertations, and Problem Reports

In this study, the thermal and mechanical properties of two types of concrete were measured. The first type contained ground granulated blast furnace slag, and the second type contained Class F fly ash. The compressive and splitting tensile strength, static elastic modulus, thermal conductivity, adiabatic temperature rise, shrinkage, and compressive creep of the two concretes were measured. Then, the experimental shrinkage and compressive creep results were compared to ACI 209.2R-08 using the material properties of each mix design. Additionally, two semi-adiabatic designs were made and compared with the adiabatic calorimetry measurements. Also, in this study, the thermal conductivity of concrete …

Monotonic Response Of Rc Exterior Beam-Column Joints Reinforced With Filler-Modules And Frp Composite Wraps/Gussets, Praveen Kumar Reddy Majjigapu

Graduate Theses, Dissertations, and Problem Reports

A review of post-earthquake reconnaissance studies revealed that reinforced concrete (RC) structures, designed and built before the development of Uniform Building Code (UBC) seismic design guidelines in 1976, have suffered complete collapse or severe damages due to the brittle failure of exterior beam-column joints. Over the past 50 years, several studies were conducted to strengthen exterior joints of in-service structures, with limited emphasis on developing simple, economic and durable repair strategies to improve energy absorption through large inelastic joint deformations. Even less emphasis was devoted to developing repair procedures that minimize stress-concentrations at joint corners and enhancing the strength, ductility, …

Design And Development Of A Multi-Nodal Methane Detection System For Longwall Coal Mining, Amber P. Barr

Graduate Theses, Dissertations, and Problem Reports

Methane (CH4) explosions pose significant dangers in longwall mining that may lead to injuries and fatalities. Safety is improved through diligent monitoring of CH4 concentration. Currently, regulations require a CH4 monitor be placed on the shearer, downwind of the cutting head. Portable monitor measurements must be taken at various times and locations. If any CH4 monitor measures a concentration greater than 1%, a warning signal must be given. Based on previous research and the location of the CH4 monitor mounted on the shearer (closest monitor to the face), if 1% methane is measured, the concentration at the face may be …

Experimental And Field Evaluation Of Frp Pedestrian Bridge Decks, Kalrav Singh Tomer

Graduate Theses, Dissertations, and Problem Reports

Traditional materials such as steel, timber, and concrete have continued to dominate their usage in civil infrastructure. They offer great advantages like strength and stiffness but at the same time they pose major issues in terms of durability and maintenance. Fiber reinforced polymer (FRP) exhibits outstanding properties like lightness, excellent corrosion and wear resistance along with superior thermo-mechanical properties. Glass FRPs (GFRPs) have emerged as one of the best alternatives in the field of civil infrastructure. It has been more than four decades since fiber reinforced polymer (FRP) composites have gained notable applications in civil infrastructure industry. However, FRPs have …

Plasmon-Enhanced Optical Probes For Sensing Of Drug Metabolite, Jennifer Boryczka

Graduate Theses, Dissertations, and Problem Reports

An Au@SiO₂ core-shell nanostar structure was synthesized along with CuInS2 quantum dots. The quantum dots display near-infrared fluorescence. In this work, the nanostar structure was functionalized with antibodies and then was utilized as a SERS probe for drug metabolite detection. Drugs are an illicit substance that police, medics, and hospitals need to know if an individual is under the influence of but that individual will not always be willing or able to provide that information. A sensor based on this new probe has been developed for detection of drug metabolites in buffer.

Assessment Of Heat Stress For Outdoor Work Conditions In Saudi Arabia, Jamal Alanazi

Graduate Theses, Dissertations, and Problem Reports

Outdoor workers have an increased risk of heat stress in Saudi Arabia since it is one of the hottest places in the Middle East. Recently, the government decided to limit outdoor work hours during the months of June, July, and August every year, and banned working under the direct sunlight from 12:00 to 03:00 p.m., although outdoor workers in the petroleum, natural gas, or emergency maintenance work industries are exempt from this prohibition. Traditionally, the efforts by safety and health professionals to mitigate work-related heat injury has been directed toward the assessment of environmental heat stress (e.g., wet-bulb globe temperature), …

Assess The Performance Against Ets And Pm1 And Evaluate The Users’ Experiences Of Comfort Of Nasal Filters, Ibrahim Almuhaidib

Graduate Theses, Dissertations, and Problem Reports

Many cities around the world experience severe air pollution. According to the World Health Organization (WHO), 7 million people die annually from exposure to small airborne Particulate Matter (PM) that is found in atmospheric pollution. Particulate matter in atmospheric pollution is one of six classifications of common air pollutants and is typically referred to as PM₁ and PM_2.5. Particulates designated as PM₁ and PM_2.5 refer to particles having aerodynamic diameters of 1 or 2.5 micrometer (µm), respectively. These size ranges of particles are the most commonly found in air pollution. It is hard to differentiate …

Interoperability Of Ip-Based Cameras, Faythe C. Maston

Graduate Theses, Dissertations, and Problem Reports

In this day and age of advancing technology and increasing crime, more and more citizens are investing in technology to increase their personal security. One such technology is the use of home-based IP security systems. These systems are comprised of one or more IP-based security cameras with owners preferring to have a way to view all camera feeds at once. Since not all security cameras are made to interact with each other, it is necessary to find a program that allows a user to view all security cameras at once, regardless of what brand of cameras they use. After researching, …

The Influence Of Spatial Variance On Rock Strength And Mechanism Of Failure, Danqing Gao

Graduate Theses, Dissertations, and Problem Reports

The heterogeneity in the rock formation affects both rock behavior and the strength. The effect of heterogeneity is observed both at the laboratory scale and at the rockmass level. The mechanical properties of intact rock vary considerably at laboratory scale and often an average value is used for design purposes. Similarly, the values are arbitrarily scaled when used at rockmass level. In underground coal mines, the effect of variability of properties is often observed with the erratic roof failure events that occur throughout the mine. The approach often was to use the deterministic values from limited site data to estimate …

Evaluation Of Control Strategies For Overhead Work Using Electromyography Of Rotator Cuff Muscles, Hossein Motabar

Graduate Theses, Dissertations, and Problem Reports

Work-related musculoskeletal disorders (MSDs) of shoulder have a significant impact on overall health and economics in the industrialized nations. Rotator cuff is the most frequently injured region in the shoulder complex. Overhead work is considered as one of the most predominant causes of rotator cuff injuries. The workers in construction, automotive, and aerospace industries are routinely exposed to overhead exertions. Elimination of overhead work is nearly impossible due to various task and technology constraints. Therefore, appropriate intervention strategies based on the engineering and administrative controls opt to be used to prevent the hazardous impact of overhead exertions. The objective of …

Comprehensively Improved Electrochemical Performance Of Lithium-Sulfur Batteries By “Chemical Anchors” And Lithium Anode Modification, Zhipeng Zeng

Graduate Theses, Dissertations, and Problem Reports

Lithium-sulfur battery is considered to be one of the most promising contenders for the next generation high-energy storages due to their high theoretical energy density (~2600 W h kg^-1). However, a series of issues, especially for the dissolution of lithium polysulfides (LiPSs) with their “shuttle effect” and dendrite formation on the lithium anode, greatly limit their widely commercial applications. Starting from a brief overview of conventional methods to solve these problems, the achievements spotlighted in this research work mainly focus on the structure design of cathode materials by employing “chemical anchors” to effectively suppress the diffusion of LiPSs, …

Upstream Tailings Dam - Liquefaction, Mladen Dragic

Graduate Theses, Dissertations, and Problem Reports

The collapse of Dam I, tailings dam, at Vale S.A.’s (“Vale”) of the Córrego do Feijão Iron Ore Mine in Brazil was an accident that caused over 270 casualties and made irreparable damage to the surrounding environment. The exact reason for the failure is not known however, liquefaction was suspected to be the most influencing factor in the failure. Liquefaction failure of impoundment is increasing concern in the mining community and especially mine planners who will have to design and build the tailings dam. Different design methods are available with varied degree of challenges. Upstream construction methods, as one of …

Development Of Software-Only Simulation Test Beds (Sost) For Spacecraft And Smallsats, Scott Alan Zemerick

Graduate Theses, Dissertations, and Problem Reports

Software-only-Simulation Test Beds (SoST) are beginning to become more popular among aircraft, spacecraft, and smallsat embedded system developers due to the high cost of duplicating hardware test beds.

SoSTs provide a software-only, or virtual test bed, that creates a “digital twin” that contains software models of the ETUs and often includes modeled components such as flight computers, busses (e.g., MIL-STD-1553, SPI, I2C), compact PCI (cPCI) backplane cards, sensors, and actuators. The ultimate goal of a SoST is for it to run the native system software compiled-binary on its native CPU architecture (e.g., PowerPC, LEON3/4, ARM) on a standard X86 personal …

Evaluation Of Fitts’ Throughput As A Possible Performance Measure For Manual Assembly Tasks, Pradyumna Bettagere Jagadish

Graduate Theses, Dissertations, and Problem Reports

Assembly lines are the backbone of the manufacturing sector. Workers at the assembly lines are expected to perform fast pace hand-arm exertions with precision and accuracy. To protect the workers from injuries, OSHA mandates the use of personal protective equipment (PPE) including gloves. Certain assembly operations require the use of special gloves. Some of these gloves can inhibit hand performance, further increasing the task difficulty. The Index of Difficulty (ID) is a metric measured in ‘bits’ quantifies task difficulty through the quotient of target width and target motion, i.e., distance travelled. The time required to complete the target motion is …

Performance Study Of Five Different Cabin Air Filters In The Laboratory And On-Road Drive, Fahad Alqahtani

Graduate Theses, Dissertations, and Problem Reports

One of the aims of installing ventilation filters in a car is to prevent vehicle occupants from inhaling potentially harmful aerosols emanating from the environment. Vehicle cabin filters are essential in ensuring that a vehicle's air conditioning system provides clean air to its occupants. The purpose of the cabin filter is to improve air quality inside the car to provide better comfort and better protect occupants from experiencing unwanted respiratory problems. Using cabin filters in air conditioning systems is a common practice in modern vehicle manufacturing. Scientists and engineers are continually seeking new ways of improving the efficiency and effectiveness …

Terrain Aware Traverse Planning For Mars Rovers, Gabrielle Hedrick

Graduate Theses, Dissertations, and Problem Reports

NASA is proposing a Mars Sample Return mission, to be completed within one Martian year, that will require enhanced autonomy to perform its duties faster, safer, and more efficiently. With its main purpose being to retrieve samples possibly tens of kilometers away, it will need to drive beyond line-of-sight to get to its target more quickly than any rovers before. This research proposes a new methodology to support a sample return mission and is divided into three compo-nents: map preparation (map of traversability, i.e., ability of a terrain to sustain the traversal of a vehicle), path planning (pre-planning and replanning), …

A Study Of Impact Protection Of Metacarpal Gloves, Faisal Mohammed Alessa

Graduate Theses, Dissertations, and Problem Reports

Work-related wrist, hand, and finger injuries are highly prevalent in manufacturing and extractive industries. An analysis of mining-related hand injury data from over the past two decades (Alessa et al., 2020) showed that hand injuries caused by insufficient protection against impact loads (e.g. struck by accidents) were categorized with high severity. Existing literature lacks clear classification and quantification methods for the protection provided by impact-resistant gloves (i.e. metacarpal gloves). A new method to establish a quantitative measure of performance for commonly used metacarpal gloves was developed and evaluated.

In the first specific aim, an experimental study using cadaveric hand specimens …

Green Completion As A Mitigation For Btex Exposure In Gas Flaring: Nigeria Case Study (Exposure Assessment And Cost Model), Akintunde S. Akinyemi

Graduate Theses, Dissertations, and Problem Reports

Gas flaring is an essential part of the oil and gas industry safety and waste management procedures; however, it presents a potential exposure to BTEX compounds, a group of Non-Methane Volatile Organic Compounds (NMVOC), within up to a 10-mile radius of the flare point. The physical and the psychological cost of the journey to work, make employees live close to the workplace. This study examined the perceived exposure of oil and gas industry workers to possible carcinogenic emissions outside the workplace. It looked at the outcomes of the exposure to BTEX through gas flaring drawing on archival data and using …

Modeling Of Rotary Packed Beds For Reactive And Non-Reactive Systems, Chinyere Evangeline Ezeobinwune

Graduate Theses, Dissertations, and Problem Reports

Rotary packed beds (RPBs) are used in a wide range of reactive and non-reactive applications. In this research, a 2-d, first-principles, dynamic model of a non-reactive RPB that is used for heat exchange between the outgoing flue gas from a power plant and the incoming air to the boiler/pulverizer of the power plant is developed. A 2-d, first-principles model of a reactive RPB is developed where a functionalized metal-organic framework (MOF) is used for CO₂ capture.

For the non-reactive system, a Ljungstrom-type air preheater (APH) is considered. Existing models for these rotating heat exchangers are typically 1-d. There are …

Fully Compressible Hydrodynamic Simulation Of Non-Equidiffusive Premixed Flames Propagation In Channels, Olatunde A. Abidakun

Graduate Theses, Dissertations, and Problem Reports

Premixed combustion remains of fundamental interest in energy generation and propulsion systems as well as in implementation of safety measures for residential and industrial accidental fire explosions. While the fast pace and complex nature of the combustion process has previously necessitated the analytical and computational studies to employ the simplifying assumption of equidiffusivity, when the Lewis number defined as the thermal-to-mass diffusivities ratio is unity , the ongoing advancements in technology and the requirements for efficiently operating combustors over a wide range of conditions make the combustion process more non-equdiffusive ( ) than ever. The impact of non-equidiffusivity on the …

Evaluating The Polishing Of Skid Aggregates In Asphalt Using The British Pendulum Tester, Allison Nicole Givens

Graduate Theses, Dissertations, and Problem Reports

To ensure the pavements in West Virginia have adequate skid resistance the Division of Highways evaluates and approves skid resistant aggregate sources for all wearing courses on roads with an ADT of 3,000 or greater. Unfortunately, the supply of skid aggregates in West Virginia is depleting quickly. To find a potential alternative to using skid resistant aggregates, laboratory polishing of asphalt samples was performed using a Circular Track Polishing Machine, and friction was tested using a British Pendulum Tester. The experiment was designed to investigate how a specific aggregate type provides skid resistance to a hot asphalt mixture.

The objective …

Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves

Graduate Theses, Dissertations, and Problem Reports

Having been theorized in 1947, it was not until 2004 that graphene was first isolated. In the years since its isolation, graphene has been the subject of intense, world-wide study due to its incredibly diverse array of useful properties. Even though many billions of dollars have been spent on its development, graphene has yet to break out of the laboratory and penetrate mainstream industrial applications markets. This is because graphene faces a ‘grand challenge.’ Simply put, there is currently no method of manufacturing high-quality graphene on the industrial scale. This grand challenge looms particularly large for electronic applications where the …

Experimental, Computational And Analytical Studies Towards A Predictive Scenario For A Burning Accident, Furkan Kodakoglu

Graduate Theses, Dissertations, and Problem Reports

Historically, accidental gas and dust explosions constitute one of the major hazards to both personnel and equipment in the process industries. The current knowledgebase on such explosions does not provide an acceptable level of risk. Therefore, novel preventive mining/fire safety strategies, based on a rigorous predictive scenario for burning accidents, are critically needed. The present dissertation is devoted to such a predictive scenario, with a particular focus on the flame and pressure evolutions in explosions encountered in an enclosure with or without obstructions. The experimental component of this dissertation comprises a series of experiments on explosion venting. Specifically, the influence …

Impact Of Particle Injection On Gas Flow At Elevated Pressure: A Numerical Study, Ansan Pokharel

Graduate Theses, Dissertations, and Problem Reports

Modeling of a turbulent two-phase gaseous-solid flow still faces challenges. The present study is devoted to two-phase flow in an annular pipe (hollow cylinder) operating at an elevated pressure of 15 bar and moderate Reynolds numbers of circa 6 x 10³. The influence of the various factors – such as the particle loading, the interaction between the phases, and turbulent dispersion – on the flow dynamics is systematically studied by means of the computational simulation employing the ANSYS FLUENT commercial package. To be specific, particle loading with a volumetric fraction of 1.2 % is defined as high particle …

Towards Large Eddy Simulation Of A Staged, Pressurized Oxy-Fuel Combustor, Alain Islas Montero

Graduate Theses, Dissertations, and Problem Reports

Identified by the DoE among the novel and transformational technologies, staged-pressurized oxy-fuel combustion (SPOC) is a promising low-cost, low-emission, and highly efficient tool for carbon capture utilization and storage (CCUS), with pulverized coal burning under elevated pressures and low recycled flue gas. A lab-scale SPOC facility, under establishment at Washington University in St. Louis (WUSTL), causes the critical need to develop accurate and reliable computational models to assist the ongoing WUSTL experiments. This constitutes the driving motivation of the present work. Specifically, comprehensive three-dimensional Large-eddy simulations (LES) of the lab-scale SPOC reactor, with most of important characteristics of a multi-phase …