Digital Commons Network^™

Solar Solution For Closed Ccr Units And Adjacent Land, Chris Fairey

World of Coal Ash Proceedings

Solar Solution for Closed CCR Units and Adjacent Land Chris Fairey1, Kenny Hughes1 1Watershed Geo, 1125 Sanctuary Pkwy, Suite 180, Alpharetta, GA 30009 KEYWORDS: Solar, Racking, Brownfield, Greenfield, Slopes, PowerCap® ABSTRACT With the reduction in coal fired power generation, there is a consistent trend in the industry to supplement generation with solar power. The property located within and surrounding these decommissioned power plants offers a significant opportunity to create a renewable solar power asset. The PowerCap® Nail to Rail System, developed by Watershed Geo, is an advanced solar racking solution designed for sites that do not require environmental closure such …

Abundances Of Elements In Global Coals, Shifeng Dai

World of Coal Ash Proceedings

The abundance of elements in coal is important not only because it provides a solid scientific and practical foundation for various geochemical comparisons, but also because it helps address broader questions in Earth Sciences. In this study, data on major and trace elements in global coals comprising hundreds of thousands of coal samples were compiled from peer-reviewed journal articles, books, various databases, dissertations, and technical reports. These data formed the basis for estimating element abundances in global coals presented in this study. All collected data were rigorously screened for reliability, and any records with questionable quality were excluded from the …

Consolidation Modeling To Support Closure Planning Of An Upstream Raise Ccr Surface Impoundment Containing Fgd Material, Tanya Walkenbach, Craig Schuettpelz, Todd Stong, Shane Stockdill

World of Coal Ash Proceedings

Rainbow Energy Center’s (REC’s) Coal Creek Station has managed calcium sulfite flue gas desulfurization (FGD) material in composite-lined upstream raise surface impoundments since 2001. The upstream raise surface impoundment utilizes bottom ash (drainage zone) and fly ash (structural zone) produced at Coal Creek Station to contain the FGD placement. FGD material was hydraulically sluiced to the center of the 110-acre Upstream Raise 92 (UR92) coal combustion residual (CCR) unit between 2001 and 2021. The FGD was deposited to a maximum thickness of approximately 100 feet in the center of the unit. Significant consolidation of FGD material occurred with subsequent FGD …

Investigation Of A Historical Coal Combustion Residuals Management Unit (Ccrmu), Todd Stong, Shane Stockdill, Erin Hunter

World of Coal Ash Proceedings

Rainbow Energy Center’s (REC’s) Coal Creek Station has managed coal combustion residuals (CCR) in various engineered impoundments and landfills since plant operation began in 1978. Since then, waste containment methods have evolved resulting in significant changes to their CCR management practice. In the late 1980s and early 1990s REC closed several existing CCR units with natural soil liners and constructed several new CCR units with composite liner systems. One of the closed units was an area now referred to as North Section 16, an impoundment that received CCR including bottom ash, fly ash, and flue gas desulfurization material. North Section …

Transportation Logistics Panel, John Ward, Andrew Vollmer, Tracy Zea, Marci Jenks

World of Coal Ash Proceedings

As the industry shifts from freshly generated ash to harvested materials and advanced utilization, logistics is becoming one of the primary drivers of project success or failure. This moderated panel will explore how sourcing, transportation, and storage realities are changing — and what project teams most often underestimate when working with harvested coal ash. Panelists will discuss what breaks, what becomes more complex, and how logistics considerations are reshaping planning and development.

Optimization Of Remedial Strategies For Ccr Site Corrective Action Through Advanced Geochemical Modeling, Cole Mayer, Pj Nolan

World of Coal Ash Proceedings

The power industry is actively designing and implementing corrective measures for Coal Combustion Residuals (CCR). In many cases, these measures include active remedies such as pump and treat, in-situ injection, or reactive barriers, all of which demand a thorough understanding of the underlying geochemical system. Depending on the geochemical characteristics of an aquifer, different chemical reagents can achieve varying degrees of success or even be detrimental to the remediation of the site. Advanced geochemical modeling is an invaluable tool for developing a remedy that is optimized to the site-specific geological, hydrological, and geochemical environment. In the case study presented here, …

Application Of Stable Isotopes In An Alternative Source Demonstration, Alison O'Connor

World of Coal Ash Proceedings

Stable isotope analysis is commonly used in age dating, provenance studies and to differentiate between sources of groundwater. Multiple studies have shown that strontium and boron isotopic ratios can be successfully used in identifying CCR impacts to groundwater. This talk presents an applied case study using boron and strontium isotopes in conjunction with additional geochemical approaches in an alternative source demonstration. Boron and strontium isotopes were measured in both groundwater and CCR leachate over sampling events from 2019 to 2025. The data revealed that strontium and boron isotopic signatures in groundwater near the CCR unit differed significantly from both site-specific …

Distinguishing Ccp From Nuclear Impacts In Groundwater, Lea Millet

World of Coal Ash Proceedings

As the energy transition from fossil fuels to other generation technologies continues, many companies worldwide are evaluating the feasibility of constructing nuclear power plants at sites previously used for coal-powered generation. Thermal power plant sites offer advantages for siting nuclear generation such as proximity to cooling water and grid connections; however existing impacts to groundwater from coal combustion product (CCP) management units may confound monitoring programs designed to detect impacts from nuclear operations. For example, boron and lithium may be present in waters associated with CCP management and nuclear power plant operations, and potassium that often has concentrations above background …

Ccr Landfill Closure Challenges, Solutions And Innovation, Jay Mokotoff, Drew Browning, Steve Applegate

World of Coal Ash Proceedings

CCR landfills can present unique design and construction challenges for the industry when closing these units at the end of their life. In comparison to CCR surface impoundments, CCR landfills typically have greater flexibility under the CCR Rule for operations and beneficial use purposes and may not have defined closure dates which results in some of these closures extending further into the future. However, as coal burning plants continue to shudder, the closure of these landfills is rapidly approaching. This presentation will focus on the challenging site conditions, site specific considerations and potential solutions when designing and constructing the landfill …

Engineering Granulometry To Optimize Performance Of Reclaimed Ash, Russell Hill

World of Coal Ash Proceedings

As utility production of fresh fly ash declines, the concrete industry is turning to reclaimed and beneficiated materials to maintain reliable SCM supply. This transition creates an opportunity not only to secure volumes but to engineer improved performance. The ReCinis™ beneficiation process enables this by providing controls that tune particle-size distribution (PSD), sphericity, packing behavior, surface area, and surface activation. Processing trials show that blends combining fine ground fractions with spherical, broad-graded hydrocyclone overflow (OF) materials can balance high reactivity with favorable rheology. Mechanochemical activation during grinding appears to increase reactivity beyond what surface-area metrics alone predict, likely through removal …

Alternative Cover Permitting And The Ccr Rule, Evan Andrews, Victor Damasceno

World of Coal Ash Proceedings

Federal rules (40 CFR Parts 9, 257 and 261) that regulate coal combustion residuals (CCR) created a significant demand associated with closure of coal ash management and storage facilities using liner systems. Timelines associated with these facility closures combined with substantial project scale and potential for future mining /reuse has driven the need for closure systems that perform beyond the prescriptive soil / geomembrane caps outlined in the federal regulations. As outlined in section 257.102 (d)(3)(i) of the CCR Rule, the standard cover system must include an infiltration layer of at least 18 inches of earthen material and an erosion …

Sustainability And Waste Diversion At Tva Shawnee "Project Phoenix", Bryan Jacob, Shane Harris

World of Coal Ash Proceedings

An engineered turf closure system can serve as an ideal foundation for a solar energy system to be installed atop coal combustion residual (CCR) impoundments. This approach not only enables productive power generation during the post-closure period, it also preserves opportunities for recovery and beneficial use of CCR material in the future. “Project Phoenix” at TVA’s Shawnee Fossil Plant offers an illustrative example. This paper will cover the sustainability benefits of the companion ClosureTurf® and PowerCap® systems installed at that site as well as waste diversion activities undertaken during construction to recycle as much as practical and minimize waste destined …

Demystifying Large Language Models: How Ai Is Transforming Data, Compliance, And Decision-Making In Coal Ash And Environmental Management, Scott Pfeiffer

World of Coal Ash Proceedings

The environmental and coal combustion residuals (CCR) industries generate vast amounts of information—from groundwater monitoring reports and RCRA documentation to closure plans and analytical data. Managing, interpreting, and communicating this information is a growing challenge for utilities, regulators, and consultants alike. Large Language Models (LLMs), such as OpenAI’s GPT architecture, represent a breakthrough in how organizations can interact with their technical data. These models use deep neural networks trained on billions of words to understand, summarize, and generate language with human-like accuracy. When securely adapted for enterprise use, LLMs can automate routine reporting, extract data from technical documents, generate regulatory …

Expert Perspectives On The U.S. Coal Combustion Products Market – Now, Then, And The Future, Mark Rokoff, David Cox, Walter Lemaire, John Ward

World of Coal Ash Proceedings

This panel discussion will explore the continued evolution of the U.S. coal combustion products market, with a focus on the impacts of dynamic regulatory and market forces. Invited expert panelists will share perspectives on developments over the past several years (building on discussions from WOCA 2022 and WOCA 2024), current conditions, and expected future trends—particularly those likely to shape the market between 2026 and 2030. The discussion will address the interrelated markets for engineering, construction, and beneficiation of ash from both operating and inactive plants. Panelists will offer perspectives relevant to the full coal ash industry, from owner/operator organizations to …

Subsurface Delineation Of Coal Combustion Residuals Using Multiple Geophysical Methods, Eric Hageman, Adam Rak, Thomas Jordan, Kate Mckinley

World of Coal Ash Proceedings

Geophysical techniques provide alternative methods of Coal Combustion Residual (CCR) delineation and characterization to supplement more invasive boring programs used for beneficial reuse planning. A demonstration project was designed to characterize the electromagnetic and seismic stratigraphy of CCR material and test the effectiveness of three geophysical techniques: Electrical Resistivity Imaging (ERI), Transient Electromagnetic (TEM) induction, and Multi-channel Analysis of Surface Wave (MASW). The demonstration project was completed at a dry-stack CCR unit containing a variety of CCR ash, gypsum, and thin layers of drainage aggregate (limestone). During a single-day deployment, several geophysical survey tests were conducted in specific areas of …

Design Of Air-Entrained Concrete For Airport Pavements Through Local Aggregate Utilization: Performance Optimization And Economic Analysis, Li Wentao, Rizwan Qadir, Arslan Mushtaq, Hilal Khan, Kamran Jillani

Journal of Sustainable Construction Materials and Technologies

Airport pavement construction in developing countries faces critical challenges balancing international performance standards with economic constraints, while limited research exists on optimizing air-entrained concrete mixes using locally sourced materials for cost-effective solutions. This study investigated the development of economical air-entrained concrete mix designs for airport pavements utilizing Pakistani aggregates and systematic cement content optimization. Comprehensive experimental evaluation included material characterization through petrographic analysis, alkali-aggregate reactivity assessment via accelerated mortar bar testing, and mechanical property development across cement contents from 360-450 kg/m3. Air entrainment was achieved through controlled admixture dosing while maintaining target slump of 50mm. Results demonstrated that locally sourced …

Development Of Hybrid Self-Cleaning Coating Using Lanthanide-Based Light Spectral Response Material To Enhance Photovoltaic (Pv) Panel Efficiency In Operational Environment, Khishn Kumar Kandiah

Student Works (2020-2029)

The efficiency of photovoltaic (PV) panels is crucial, as solar energy has become an alternative energy source that meets today’s global energy demands. Hence, dust accumulation and spectral mismatch have major effects on the efficiency of PV panels, around 20 %, but in extreme situations, this can reach up to 64 %. Therefore, initiatives are underway to address these issues, including PV cooling systems, conventional cleaning methods, and various coatings to enhance efficiency. In this work, a novel coating is fabricated with high transparency, excellent self-cleaning properties, and good spectral-modifying properties. Two types of powder composites are employed in this …

Designing Enhanced Nonlinearity In Plasmonic Devices With Epsilon-Near-Zero Films, Kevin Tran Le

Electrical Engineering and Computer Science (MS) Theses

The growing demand for energy-efficient optical information processing motivates compact nonlinear photonic devices that can operate at low power. Silicon photonics is a mature platform for linear optical functions, but nonlinear operation remains challenging because of its weak Kerr response, two-photon absorption at telecommunication wavelengths, and limited compatibility with deeply subwavelength plasmonic confinement. This thesis computationally investigates epsilon-near-zero thin films integrated into plasmonic waveguide architectures as a route toward stronger light–matter interaction in compact nonlinear devices.

Two waveguide geometries are examined: a hybrid metal-insulator-metal plasmonic slab waveguide incorporating an ultrathin indium tin oxide epsilon-near-zero layer (5–50 nm), and a dielectric-loaded …

A Maintenance-Aware Machine Learning Framework For Network-Level Highway Pavement Condition Prediction, Jin Hwan Kim, Guk Gon Song, Youngguk Seo

Faculty Articles

This study develops and validates maintenance-aware machine learning models for predicting the Highway Pavement Condition Index (HPCI) on the Korean expressway network. Multiple regression and tree-based models were trained and tested using the pavement condition surveys archived in the Highway Pavement Management System (HPMS). A stacking regressor that integrates random forest, gradient boosting, and extreme gradient boosting as base learners exhibited the most robust predictions. Performance metrics indicated that the stacking ensemble achieved a mean absolute error of 0.21, a root mean square error of 0.31, and a coefficient of determination exceeding 0.73 on the testing dataset. Also, the residuals …

Physical And Optical Properties Of The Germanium-Arsenic-Selenium Glass Forming Region For Precision Glass Molding And Infrared Optics, Peter F. Wachtel Ii

All Dissertations

The growth and advancement of infrared optical systems for thermal imaging, multi-band imaging, hyperspectral imaging, medical diagnostics, and chemical sensing are pushing the material science community to better understand existing materials while also developing new materials. Additionally, the thermal imaging market continues to grow, and system designers are continually being asked to reduce size, weight, and power while reducing costs (SWaP-c). Market growth has shifted optics manufacturing towards higher volume processes such as precision glass molding, but this does require most materials to be recharacterized due to property changes resulting from the process. Affecting the SWaP-c requirements, manufacturing tolerances are …

Adsorption Of Pfas On Bridged Functionalized Organosilica Materials, Elisha Lawerh Kabutey

Electronic Theses and Dissertations

PFAS are hazardous contaminants that have a devastating impact on human health and the environment. Their hazardous nature has led to the development of various adsorption methods for removing these contaminants from water sources. In this study, functionalized organosilica materials were synthesized from bis[3-(trimethoxysilyl)propyl] amine using the sol-gel method. The surface amino groups of the organosilica were converted into amine hydrochloride groups. Their adsorption properties were evaluated using salts of perfluorooctanoic acid, perfluorooctanesulfonic acid, and perfluorobutanesulfonic acid. Results showed excellent adsorption capacity of the materials. Adsorption of PFAS leads to particle agglomeration and flotation of the spent material. A column …

Engineering Silicone Magnetic Fluids For Localized Radiation Attenuation During Ocular Melanoma Brachytherapy, Zachary L. Caprow

All Dissertations

Ocular melanoma is commonly treated using plaque brachytherapy; however, radiation-induced damage to healthy ocular tissues frequently results in partial or complete vision loss. This work investigates the development of an injectable, magnetically responsive silicone magnetic fluid designed to localize adjacent to the tumor and attenuate low-energy gamma radiation during treatment.

The material system consists of iron oxide nanoparticles surface-functionalized with a siloxane polymer, in which the nanoparticles provide magnetic responsiveness and radiation attenuation, while the polymer coating ensures colloidal stability, injectability, and biocompatibility. A one-pot synthetic approach was developed wherein a functionalized siloxane polymer containing iron-affinitive groups was reacted with …

Computer Vision And Machine Learning Approaches For Defect Detection In 3d-Printed Cementitious Materials: A Systematic Review, Muhammad Ali Musarat, Ruben Paul Borg, Jingjie Wei, Carl James Debono, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

3D printing is evolving at a fast pace in both the manufacturing and construction sectors. These advancements can greatly benefit these industries. However, the 3D printing of concrete structures presents some challenges due to defects in the 3D concrete printed elements. Hence, this study systematically reviews Artificial Intelligence (AI)-driven techniques, such as Computer Vision and Machine Learning, to identify surface defects that can occur in 3D-printed cementitious material structures. The adopted methodology was the PRISMA statement with the aim of reporting the systematic review and meta-analysis. Two well-known databases, Web of Science and Scopus, were utilised for data extraction of …

Interplay Between Phase Instability And Deformation Mechanisms In Beta Titanium Alloys In Aggressive Environments, Benjamin Elbrecht

All Dissertations

Modern designs, such as commercial jet turbines, are reliant on the high temperature performance of their constituent materials. Improvements to the strength-at-temperature of materials are critical to the continued advancement of efficiency and payload capacity in these advanced applications. This dissertation presents studies that progress towards this goal through the construction of a new experimental setup for complex temperature and force profiles that also accurately captures deformation behavior through non-contact measurements. Using this setup, studies into two specialty titanium alloys were executed: discovering the microscopic mechanisms responsible for the macroscale behavior and testing in conditions closely replicating aircraft turbine operating …

Enameling Coating Of Pipes: Thermal Proprieties And Corrosion Tests, Signo Reis, Genda Chen, Mike Koenigstein, Liang Fan

Materials Science and Engineering Faculty Research & Creative Works

Enamel coating on pipelines can be done in several ways such as the wet process, plasma spray, and electrostatic process. Wet process requires little capital expenses and provides an acceptable finish for industrial applications particularly when the part to be coated is small. Electrostatic process of enamel powder is most promising to coating large pipelines in field conditions. The enamel coating applied by the electrostatic process is very consistent and smooth since each particle is glass only. However, the powder is very fragile until fired and the charge retention is lowered in high humidity conditions. Coupons cut from a full-size …

Evaluation Of Iron-Phosphate Glass–Ceramic Waste Form For Electrorefiner Salt Waste Simulant Dechlorinated With Phosphoric Acid, Harmony Werth, Paige Murray, Lucas Greiner, Jade Beland, Charmayne Lonergan, Brian Riley, Krista Carlson

Materials Science and Engineering Faculty Research & Creative Works

The importance of glass and glass–ceramic nuclear waste forms has been reaffirmed in recent years by the growing interest in nuclear power as a reliable energy source. Determination of processing methods for the disposal of halide-containing wastes will be essential for the advancement of nuclear technologies such as non-aqueous fuel reprocessing. Phosphate-based dechlorination and subsequent vitrification of radioactive salt waste into an iron-phosphate waste form have been identified as a potential processing scheme for electrochemical processing waste. The impact of H₃PO₄-based dechlorination of complex salt mixtures on the vitrification process and structure of the final iron-phosphate …

Effect Of Composition On Grain-Boundary Chemistry And Fracture Behavior In High-Entropy Carbides, Caleb Schenck, Marium Mostafiz Mou, Elizabeth Pritchett, Fu Yun Tsai, Josephine Hartmann, Michael Lastovich, Sam Daigle, Kayla Yano, Matthew J. Olszta, Sanjit Bhowick, Elizabeth Kautz, Gregory E. Hilmas, William G. Fahrenholtz, Donald W. Brenner

Materials Science and Engineering Faculty Research & Creative Works

High-entropy carbides (HECs) are often treated as a single material class defined by configurational entropy; however, their properties are governed by composition-specific defects and grain-boundary chemistry. This study demonstrates that substituting a single element can qualitatively change grain-boundary structure and fracture behavior in HEC ceramics. Two HECs, (Cr,Hf,Ta,Ti,Zr)C (HEC-Cr) and (Hf,Ta,Ti,W,Zr)C (HEC-W), were examined via electron microscopy, atom probe tomography, and molecular dynamics simulations. Simulations predict preferential segregation of Cr, W, and Zr to grain boundaries. Experiments confirmed Cr enrichment at grain boundaries and the formation of W-rich nanograins along boundary networks. Mechanical testing revealed that these compositional differences translated …

Evaluating The Integration Of Bio-Based Waste Into Cement Production: A Pathway To Sustainable Building, Anja Terzić, Suzana Filipović, Adriana Peleš Tadić, Jelena Živojinović, Ivana N. Jelić, Nina Obradović, William G. Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Rapid urbanization has increased the demand for building materials, depleting natural resources used in cement production and prompting the use of alternative and waste materials. This research verifies that eggshell powder waste can fully replace limestone in clinker synthesis. Five clinkers were produced using eggshell powder, aluminum sources (bentonite, zeolite, fly ash, and kaolinitic–illitic clay), Fe-slag, and quartz sand, with mechanical preprocessing (10–30 min) before sintering at 1300 °C. Experimental tests assessed the effects of mix design and mechanical activation on clinkerization, phase formation, temperature, and mechanical properties. XRD, FTIR, and SEM/EDS confirmed consistent phase compositions and primary cement minerals. …

In-Operando Imaging For Mechanistic Insights And Process Optimization In The Biofuel-Driven Combustion Synthesis Of Cement And Precursor Phases, Shubham Agrawal, Jeffrey J. Long, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Biofuel-based combustion synthesis (BCS) is a promising low-carbon pathway for decarbonizing cement production, providing an alternative to the fossil-fuel-driven clinkering process typically conducted at ∼1450 °C. Understanding microscale combustion mechanisms is essential to efficiently transfer biofuel-generated heat to cement precursors for targeted phase formation. Unlike previous studies focusing on macro-scale parameters such as fuel content/type, porosity, and holding temperature, this work provides mechanistic insights into microscale combustion behavior, linking microstructural phenomena with macro-scale processing conditions to guide parameter optimization. In-operando microscale imaging was employed to examine combustion wave propagation, spatio-temporal temperature evolution, and microstructural transformations within reactive pellets. Two combustion …

Strong And Ductile Additively Manufactured Ti-6al-4v Through Yttrium Inoculation, Saeid Alipour, Ji Young Kim, Min Seok Kim, Arezoo Emdadi, Ju Li

Materials Science and Engineering Faculty Research & Creative Works

The unique microstructural features and thermal cycles in alloys produced by additive manufacturing (AM) techniques have led to the emergence of a new paradigm in the design and development of alloys for performance-critical applications. Despite the inherent microstructural features of AMed parts, optimizing the porosity-microstructure while acquiring desired mechanical performance has been crucial yet challenging. Hence, in many legacy alloys, achieving a strength-ductility synergy in the as-built condition without applying post-heat treatment or hybrid processes is considered an arduous task. In this research, we aimed to tailor the microstructure of the legacy Ti-6Al-4V alloy in the as-built condition by implementing …