Engineering Commons^™

Separation Of Unburned Carbon From Coal Conversion Ash: Development And Assessment Of A Dry Method, Charlotte J. Badenhorst, Nicola J. Wagner, Bruno R.V. Valentim, Karel S. Viljoen, Ana C. Santos, Alexandra Guedes

Coal Combustion and Gasification Products Journal Archive

Unburned carbon found in coal conversion ash has the potential to be used in a variety of value-added applications. However, it is first necessary to separate the unburned carbon from the rest of the ash phases. This poses challenges due to the relatively low starting carbon-in-ash values (0.4 to 7.8 wt% reported for South African sources), and the high carbon grades (ideally ∼90 wt% carbon) and recoveries that need to be achieved. In this study a dry method for the separation of unburned carbon from coal ash was developed and assessed using fly, bottom, and gasification ash samples obtained from …

Process Sustainability Evaluation For Manufacturing Of A Component With The 6r Application, Ana E. Bonilla Hernández, Tao Lu, Tomas Beno, Claes Fredriksson, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Sustainability in manufacturing can be evaluated at product, process and system levels. The 6R methodology for sustainability enhancement in manufacturing processes includes: reduced use of materials, energy, water and other resources; reusing of products/components; recovery and recycling of materials/components; remanufacturing of products; and redesigning of products to utilize recovered materials/resources. Although manufacturing processes can be evaluated by their productivity, quality and cost, process sustainability assessment makes it a complete evaluation. This paper presents a 6R-based evaluation method for sustainable manufacturing in terms of specific metrics within six major metrics clusters: environmental impact, energy consumption, waste management, cost, resource utilization and …

Fabrication And Characterization Of Planar-Structure Perovskite Solar Cells, Guoduan Liu

Theses and Dissertations--Electrical and Computer Engineering

Currently organic-inorganic hybrid perovskite solar cells (PSCs) is one kind of promising photovoltaic technology due to low production cost, easy fabrication method and high power conversion efficiency.

Charge transport layers are found to be critical for device performance and stability. A traditional electron transport layer (ETL), such as TiO₂ (Titanium dioxide), is not very efficient for charge extraction at the interface. Compared with TiO₂, SnO₂ (Tin (IV) Oxide) possesses several advantages such as higher mobility and better energy level alignment. In addition, PSCs with planar structure can be processed at lower temperature compared to PSCs with …

Use Of Ponded And Fresh Ashes From China For The Production Of Portland/Calcium Sulfoaluminate Clinkers, Tristana Y. Duvallet, Robert B. Jewell, Anne E. Oberlink, Thomas L. Robl, David Harris

Coal Combustion and Gasification Products Journal Archive

This article summarizes the use of two fly ashes in the synthesis of Portland/calcium sulfoaluminate (OPC/CSA or A/CSA) clinkers. They are from the Shentou second power plant located in the Shanxi Province and from the Zhungeer power plant located in Inner Mongolia, China. The Zhungeer ash was collected dry, and the Shentou ash is from a pond. Their chemical compositions differ highly, especially the SiO2 and Al2O3 contents. The high contents of silica and alumina make both ashes candidates as a partial or total substitute for bauxite, an expensive source of alumina, in the production of OPC/CSA clinkers. These particular …

The Use Of 3-D Highway Differential Geometry In Crash Prediction Modeling, Kiriakos Amiridis

Theses and Dissertations--Civil Engineering

The objective of this research is to evaluate and introduce a new methodology regarding rural highway safety. Current practices rely on crash prediction models that utilize specific explanatory variables, whereas the depository of knowledge for past research is the Highway Safety Manual (HSM). Most of the prediction models in the HSM identify the effect of individual geometric elements on crash occurrence and consider their combination in a multiplicative manner, where each effect is multiplied with others to determine their combined influence. The concepts of 3-dimesnional (3-D) representation of the roadway surface have also been explored in the past aiming to …

Image-Based Roadway Assessment Using Convolutional Neural Networks, Weilian Song

Theses and Dissertations--Computer Science

Road crashes are one of the main causes of death in the United States. To reduce the number of accidents, roadway assessment programs take a proactive approach, collecting data and identifying high-risk roads before crashes occur. However, the cost of data acquisition and manual annotation has restricted the effect of these programs. In this thesis, we propose methods to automate the task of roadway safety assessment using deep learning. Specifically, we trained convolutional neural networks on publicly available roadway images to predict safety-related metrics: the star rating score and free-flow speed. Inference speeds for our methods are mere milliseconds, enabling …

Quantifying The Impact Of Transportation Network Companies (Tncs) On Traffic Congestion In San Francisco, Sneha Roy

Theses and Dissertations--Civil Engineering

This research investigates whether Transportation Network Companies (TNCs), such as Uber and Lyft, live up to their stated vision of reducing congestion by complementing transit and reducing car ownership in major cities. The objective of this research study is to answer the question: are TNCs are correlated to traffic congestion in the city of San Francisco? If found to be so, do they increase or decrease traffic congestion for the case of San Francisco? If and how TNC pickups and drop-offs impact traffic congestion within San Francisco? And finally, how does the magnitude of this measured command of TNCs on …

Analysis Of The Pile Load Tests At The Us 68/Ky 80 Bridge Over Kentucky Lake, Edward Lawson

Theses and Dissertations--Civil Engineering

Large diameter piles are widely used as foundations to support buildings, bridges, and other structures. As a result, it is critical for the field to have an optimized approach for quality control and efficiency purposes to measure the suggested number of load tests and the required measured capacities driven piles. In this thesis, an analysis of a load test program designed for proposed bridge replacements at Kentucky Lake is performed. It includes a detailed site exploration study with in-situ and laboratory testing. The pile load test program included monitoring of a steel H-pile and steel open ended pipe pile during …

Investigation Of Atmospheric Effects On Vapor Intrusion Processes Using Modelling Approaches, Elham Shirazi

Theses and Dissertations--Civil Engineering

Most people in the United States (US) spend considerable amount of time indoors—about 90% of their time as compared to outdoors, which makes the US population vulnerable to adverse health effects of indoor air contaminants. Volatile organic compound (VOC) concentrations are well-known to be higher in indoor air than outdoor air. One source of VOC concentrations in indoor air that has gained considerable attention in public health and environmental regulatory communities is vapor intrusion. Vapor intrusion is the process by which subsurface vapors enter indoor spaces from contaminated soil and groundwater. It has been documented to cause indoor air contamination …

Evaluate Probe Speed Data Quality To Improve Transportation Modeling, Fahmida Rahman

Theses and Dissertations--Civil Engineering

Probe speed data are widely used to calculate performance measures for quantifying state-wide traffic conditions. Estimation of the accurate performance measures requires adequate speed data observations. However, probe vehicles reporting the speed data may not be available all the time on each road segment. Agencies need to develop a good understanding of the adequacy of these reported data before using them in different transportation applications. This study attempts to systematically assess the quality of the probe data by proposing a method, which determines the minimum sample rate for checking data adequacy. The minimum sample rate is defined as the minimum …

E-Construction Technologies For Efficient Highway Construction Inspections, Dhaivat Patel

Theses and Dissertations--Civil Engineering

Over recent years, organizations such as the Federal Highway Administration and Departments of Transportation across the United States have showed interest in automating highway construction processes. The addition of e-Construction and other advanced technologies can significantly improve the efficiency and safety of highway paving operations, specifically paving inspections. Activities such as collecting load tickets, tracking pavement lay-down temperatures, and monitoring roller movement are antiquated practices that DOT inspectors perform during paving operations. E-Ticketing, Paver Mounted Thermal Profiling, and Intelligent Compaction were proposed to automate paving inspections and were recently tested in two resurfacing pilot projects in the state of Kentucky. …

Leaching Characteristics Of Rare Earth Elements From Bituminous Coal-Based Sources, Xinbo Yang

Theses and Dissertations--Mining Engineering

The demand for rare earth elements (REEs) has increased over the last decade due to applications in high technology devices including those in the defense industry. The recovery of REEs from primary sources such as rare earth minerals are viable using physical separations followed by chemical processing. However, weak market values and environmental concerns have limited the viability of such operations. On the other hand, REE recovery from secondary sources such as apatite ore, bauxite waste, and waste recycling, provides an opportunity to take advantage of a resource that does not require mining costs as well as other associated costs …

Thermodynamic Modeling And Equilibrium System Design Of A Solvent Extraction Process For Dilute Rare Earth Solutions, Alind Chandra

Theses and Dissertations--Mining Engineering

Rare earth elements (REEs) are a group of 15 elements in the lanthanide series along with scandium and yttrium. They are often grouped together because of their similar chemical properties. As a result of their increased application in advanced technologies and electronics including electric vehicles, the demand of REEs and other critical elements has increased in recent decades and is expected to significantly grow over the next decade. As the majority of REEs are produced and utilized within the manufacturing industry in China, concerns over future supplies to support national defense technologies and associated manufacturing industries has generated interest in …

Development And Preliminary Evaluation Of An Integrated Individual Nozzle Direct Injection And Carrier Flow Rate Control System For Pesticide Applications, Joe D. Luck, Scott A. Shearer, Michael P. Sama

Biosystems and Agricultural Engineering Faculty Publications

Direct injection systems for agricultural spray applications continue to present challenges in terms of commercialization and adoption by end users. Such systems have typically suffered from lag time and mixing uniformity issues, which have outweighed the potential benefits of keeping chemical and carrier separate or reducing improper tank-mixed concentration by eliminating operator measurements. The proposed system sought to combine high-pressure direct nozzle injection with an automated variable-flow nozzle to improve chemical mixing and response times. The specific objectives were to: (1) integrate a high-pressure direct nozzle injection system with variable-flow carrier control into a prototype for testing, (2) assess the …

Conceptual Groundwater Remedial Alternatives At Coal Combustion Residuals Sites†, Herwig Goldemund, Jeffrey M. Ahrens

Coal Combustion and Gasification Products Journal Archive

Groundwater below many basins that have been used to store coal combustion residuals (CCRs) may have concentrations of certain inorganic constituents in excess of applicable regulatory standards. Given that many inorganic CCR constituents are also naturally occurring in the aquifer matrix, their detection may not always be indicative of a release from the CCR unit. Inorganics may be present at elevated levels in groundwater due to natural or background conditions, or due to changes to the aquifer geochemistry resulting from the presence of the CCR basin, which then mobilizes these naturally occurring constituents beneath the CCR unit. Care must be …

Fly Ash Composites, A Step Toward Pond Ash Composites, Kunigal N. Shivakumar, Wade H. Brown, Kazi A. Imran

Coal Combustion and Gasification Products Journal Archive

The study demonstrated that ash composites made from polyurethane and fly ash are able to reduce leaching of coal ash inorganics to less than one-third of the U.S. Environmental Protection Agency’s maximum containment limit even after being exposed to an accelerated water circulation system for 14 months. Even if these ash blocks are broken, the composite is safe. The concept of encapsulation of fly ash into ash composite by using a polar polymer to bind the fine inorganic particles, as nature has done in the original unburned coal, makes the ash composite safe. The ash composites have compression and f …

In Situ Characterization Of Mixture Of Fly Ash And Fluidized Gas Desulfurization By-Product At Tennessee Valley Authority’S Gallatin Ash Stacking Facility†, David J. White, Pavana Vennapusa, Brendan Fitzpatrick, Jason F. Hill, Nicholas Mcclung

Coal Combustion and Gasification Products Journal Archive

This article presents the results of field and laboratory testing performed on a new coal combustion product (CCP) derived from a mixture of fly ash and dry fluidized gas desulfurization by-product at the Tennessee Valley Authority’s Gallatin Fossil Plant in Gallatin, TN. Field testing included geospatial mapping using a vibratory smooth drum roller instrumented with a validated intelligent compaction (VIC) system and by field testing to characterize elastic modulus, shallow shear wave velocity, moisture content, dry density, and shear strength properties. Field testing was performed in areas where the CCP had been placed several days before testing and in areas …

Managing Springs Emanating From Coal Combustion Residual Disposal Impoundments, Mark L. Orzechowski, Daniel M. Tolmer

Coal Combustion and Gasification Products Journal Archive

Affected springs emanating from coal combustion residual (CCR) disposal impoundments where “wet disposal” methods were employed is a typical issue that frequently needs to be addressed during operation and management of these facilities. Identifying potential effects on a spring is typically accomplished through regularly scheduled field reconnaissance and laboratory analyses. Analytical testing is performed to characterize the chemical constituents present in the spring water. The management approach employed for specific springs is developed on the basis of several factors, including chemical composition and flow rate of the spring water, regulatory requirements and discharge standards, available treatment technologies, facility operations, site …

Shear Strength Of Coal Combustion Product By Vane Shear, Wesley J. Herweynen, Christopher A. Bareither, Joseph Scalia

Coal Combustion and Gasification Products Journal Archive

The objective of this study was to evaluate the shear strength of a coal combustion product (CCP) by using the vane shear test. A series of small-scale vane shear (SS-VS; diameter = 12.7 mm and height = 25.4 mm) and large-scale vane shear (LS-VS; diameter = 25 mm and height = 50 mm) laboratory tests were conducted. Undrained and drained strength envelopes were determined using consolidated undrained triaxial compression tests, and drained strength was checked via consolidated drained direct shear. In addition, effects of (1) rate of vane rotation, (2) time delay between vane insertion and beginning rotation, and (3) …

Mineralogy And Geochemistry Of Feed Coals And Combustion Residues From Tunçbilek And Seyitömer Coal-Fired Power Plants In Western Turkey, Ali Ihsan Karayigit, Ozlem Yigitler, Seda Iserli, Xavier Querol, Maria Mastalerz, Riza Gorkem Oskay, James C. Hower

Coal Combustion and Gasification Products Journal Archive

This study focuses on the enrichment of elements in feed coal (FC) and combustion residues, namely, fly ash (FA) and bottom ash (BA) samples, picked up from the Tunçbilek and Seyitömer coal-fired power plants in western Turkey. The FCs in both plants have generally similar mineralogical compositions, although siderite and dolomite are more prominent in Tunçbilek and feldspar and pyrite are more abundant in Seyitömer. Minerals in the FA from both power plants are mainly quartz, hematite, magnetite, anhydrite, and mullite. Along with quartz, the Fe-oxides are dominant phases in the BA samples. Accessory minerals in the FCs, FAs, and …

Phaselous Vulgaris Growth Under The Influence Of Manufactured Coal Ash Aggregates, Sangchul Hwang, Imiraily Hernandez, Isomar Latorre, Sahid Rosado

Coal Combustion and Gasification Products Journal Archive

Manufactured coal ash aggregates (MAs) are a 2:1 (w/w) solidified composite of fly and bottom ash. The current study assessed the feasibility of beneficial utilization of MAs as a subsoil substitute for open-pit restoration to phyto-viable land. A series of indoor and outdoor experiments examined Phaselous vulgaris growth under the influence of MAs in the soil environment. With the MAs layer below the topsoil, P. vulgaris showed enhanced growth with respect to shoot height, leaf number, and leaf chlorophyll intensity. Similar growth enhancement was observed when the MAs were mixed with topsoil or applied as a micronutrient source over the …

Using The Conceptual Site Model To Efficiently And Effectively Implement Groundwater Monitoring And Corrective Action At Coal Combustion Residual Sites†, Carla Landrum, Jim Feild, Tim Glover, Alison Dunn

Coal Combustion and Gasification Products Journal Archive

On 19 October 2015, the Disposal of Coal Combustion Residuals (CCRs) for Electric Utilities final rule (CCR Rule), issued by the U.S. Environmental Protection Agency (US EPA) under Subtitle D of the Recovery and Conservation Act (RCRA), became effective. The Groundwater Monitoring and Corrective Action subsections of the CCR Rule (40 CFR §§ 257.90–257.98) set out strict requirements for groundwater monitoring at the detection and assessment levels, followed by (if necessary) groundwater characterization in support of corrective measures assessment. Since the federal CCR Rule was implemented, the US EPA has proposed and finalized some amendments, and some states have proposed …

The Role Of Ash Mineralogy On Breakthrough Pressure And Contact Angle: A Statistical Evaluation, Jenberu L. Feyyisa, John L. Daniels

Coal Combustion and Gasification Products Journal Archive

One method to minimize contaminant leaching from coal fly ash (CFA) involves modifying its surface to become water repellent. Five types of CFA, CFA-1, CFA-2, CFA-3, CFA-5, and CFA-6, were modified by three organosilane (OS) products at different mix ratios. Multiple breakthrough pressure (BP) experiments were conducted for different samples at different mix ratios to identify the performance of the modified surface to resist a positive water entry pressure. The contribution of oxides and minerals in CFA to form a water-repellent surface were analyzed without considering OS effects. Results showed that semi-log–transformed regression models can effectively establish the relationship between …

South Africa’S Power Producer’S Revised Coal Ash Strategy And Implementation Progress, Kelley Reynolds-Clausen, Nico Singh

Coal Combustion and Gasification Products Journal Archive

The South African electricity public utility Eskom has embarked on a process to increase utilisation of the ash produced through the electricity generation process at its coal-fired power stations. In the 2014–2015 financial year, 119.2 million tons of coal was consumed, producing 34.4 million tons (28.9%) of ash. About 7% of the Eskom ash is sold from 6 of the 13 coal-fired power stations. Many stations are currently running out of ash storage space, and expansion of the ash disposal facilities is required, which could affect security of supply because of limited ashing areas. Additionally, legislative requirements lead to extra …

A Total Life Cycle Approach For Developing Predictive Design Methodologies To Optimize Product Performance, Buddhika M. Hapuwatte, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Sustainable products must be designed by considering how design decisions impact their total life cycle (TLC) sustainability content. Even more so important when designing products to incorporate the technological elements of sustainable manufacturing, the 6Rs (Reduce, Reuse, Recycle, Recover, Redesign and Remanufacture), to achieve Circular Economy (CE). This paper presents the preliminary work of an ongoing research project on developing a novel framework incorporating predictive models with TLC considerations. This unique approach develops and integrates models with associated risks, and optimizes for maximizing the sustainability benefits due to design decisions. Such predictive capability is extremely useful for process planning, where …

Sustainable Production Through Balancing Trade-Offs Among Three Metrics In Flow Shop Scheduling, Amin Abedini, Wei Li, Fazleena Badurdeen, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

In sustainable manufacturing, inconsistencies exist among objectives defined in triple-bottom-lines (TBL) of economy, society, and environment. Analogously, inconsistencies exist in flow shop scheduling among three objectives of minimizing total completion time (TCT), maximum completion time (MCT), and completion time variance (CTV), respectively. For continuous functions, the probability is zero to achieve the objectives at their optimal values, so is it at their worst values. Therefore, with inconsistencies among individual objectives of discrete functions, it is more meaningful and feasible to seek a solution with high probabilities that system performance varies within the …

Designing And Redesigning Products, Processes, And Systems For A Helical Economy, Ryan Bradley, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

The Circular Economy (CE) concept has promised to unlock trillions of dollars in business value while driving a significant reduction in the world’s resource consumption and anthropogenic emissions. However, CE mainly lives in ambiguity in the manufacturing domain because CE does not address the changes needed across all of the fundamental elements of manufacturing: products, processes, and systems. Conceptually, CE is grounded in the concept of closed-loop material flows that fit within ecological limits. This grounding translates into a steady state economy, a result that is not an option for the significant portion of the world living in poverty. Therefore, …

Rotary Friction Welding Versus Fusion Butt Welding Of Plastic Pipes – Feasibility And Energy Perspective, Ramsey F. Hamade, Tarek R. Andari, Ali H. Ammouri, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

According to the Plastics Pipe Institute, butt fusion is the most widely used method for joining lengths of PE pipe and pipe to PE fittings “by heat fusion” (https://plasticpipe.org/pdf/chapter09.pdf). However, butt-welding is not energy-cognizant from the point of view of a phase-change fabrication method. This is because the source of heating is external (heater plate). The initial heating and subsequent maintenance at relatively high temperature (above 200 C for welding of high-density polyethylene pipe) is energy intensive. Rotary friction welding, on the other hand focuses the energy where and when as needed because it uses electric motor to generate mechanical …

Inventory Of Hazardous Materials Shipments Moving Into Fayette County, Kentucky, Candice Y. Wallace, Bryan Gibson, Steven Douglas Kreis

Kentucky Transportation Center Research Report

Each day, significant quantities of hazardous materials are transported through Fayette County. The bulk of the materials pass through without incident, but some vehicles carrying them are involved in roadway incidents and/or accidents. However, first responders and management personnel lack clear knowledge of what hazardous material commodities are on central Kentucky’s roads. This project was designed to provide a high level analysis of hazardous material commodity flows in Fayette County.

Investigating The Use Of In-Place Lateral Pull Off Tests To Determine The Compressive Strength Of Structural Concrete, Charlie Sun

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet’s current practice for determining the compressive strength of structural concrete consists of two methods. Both methods require that samples be delivered to an off-site facility for testing. Accordingly, affected parties on the project site must wait for the delivery of samples to the off-site facility, the performance of tests and analysis of test data, and the return of test results to the project site. Analysis of existing structural concrete requires core samples to be taken from the structural element in question. As a result, sample locations must be patched and repaired. Sampling can also potentially damage …