Materials Science and Engineering Commons^™

Lafe0.925ti0.075o3 Perovskite Coated With Ethyl Cellulose: A High-Stability, Low-Hysteresis Platform For Advanced Humidity Sensing, Akhmad Futukhillah Fataba Alaih, Djoko Triyono, Rifqi Almusawi Rafsanjani

Makara Journal of Science

Humidity sensors are pivotal in numerous sectors, such as environmental monitoring, industrial automation, and health-care. This study presents the fabrication and detailed evaluation of an advanced humidity sensor using ethyl cellulose (EC)-coated LaFe_0.925Ti_0.075O₃ (LFTO) perovskite nanoparticles synthesized via the sol-gel method. The LFTO nanopar-ticles exhibited a mesoporous structure with an enhanced surface area, which significantly improved their moisture adsorption capabilities. The innovative application of EC coating addresses critical substrate adhesion issues, enhancing mechanical stability without compromising sensor sensitivity. Comprehensive performance evaluations revealed minimal hysteresis (

Photoluminescent Studies Of Metal-Organic Frameworks For Small Molecule Sensing, Julia T. Dematteo

USF Tampa Graduate Theses and Dissertations

Metal–organic frameworks (MOFs) are highly tunable nanoporous materials with broad applications in gas separation, drug delivery, light harvesting, and chemical sensing. The incorporation of photoactive components into MOFs enables the development of optical sensors capable of detecting a wide range of analytes. Porphyrins and metalloporphyrins are particularly attractive for such applications due to their high molar absorptivity, strong emission quantum yields, and versatile interactions with chemical species.

In this work, two porphyrinic MOFs, PCN-222 and MOF1(Cd), are investigated. Both frameworks utilize tetrakis(4-carboxyphenyl)porphyrin (TCPP) as the organic linker, imparting optical functionality to the materials. Integration of TCPP into the framework induces …

Rheological Protocol To Assess And Optimize Latex Coagulation Dynamics For The Thin Glove Coagulant Dipping Process, Monday U. Okoronkwo, Kok Kong Ng, Wolfram Franke, Gaurav Sant

Chemical and Biochemical Engineering Faculty Research & Creative Works

Many products that directly impact the quality of human life today — gloves, catheters, condoms, and baby bottle teats — are made through the latex-dipping technology. While a variety of methods have been developed – e.g., particle counting, turbidimetry, microscopy, and light scattering – which are suitable for studying the coagulation of latex at very low concentrations, much less work has focused on methods suitable for in-situ characterization of latex coagulation in concentrated solutions (e.g., as relevant to the dipping process). This paper presents a process-relevant rheological protocol for assessing and optimizing latex coagulation dynamics for the thin glove coagulant …

Tuning Ion Mobility And Molecular Confinement In High-Performance Polymer Electrolytes For Energy Storage, Ezzeldien Yousef Muhammed Yousef

Theses and Dissertations

This research addresses the critical energy density limitations of aqueous supercapacitors, which are traditionally constrained by the narrow electrochemical stability window (ESW) of water 1.23 V. By employing two distinct molecular engineering strategies, this study developed high-performance electrolyte systems that significantly extend voltage stability and thermal resilience.

The first system, CsBr@PAM/HA, utilizes a polyacrylamide and hyaluronic acid hydrogel matrix. This system exploits the chaotropic nature of Cs⁺ ions to disrupt the aqueous hydrogen-bonding network, enhancing ionic conductivity to 104 mS cm^-1. Through systematic salt screening, CsBr was identified as the optimal electrolyte, enabling a stable 2.0 V …

Engineering Nanoelectrocatalytic Systems For Co2 And Nitrate Conversion Into Value-Added Chemicals, Abdelrahman Mohamed Abdelmohsen

Theses and Dissertations

The thesis addresses two major related environmental crises: nitrate pollution of water systems and the ever-increasing levels of atmospheric carbon dioxide. Both challenges are closely linked to anthropogenic disturbance of nitrogen and carbon cycles and require sustainable, energy efficient mitigation techniques. In this study, we investigate electrochemical conversion routes as a unified approach to convert these pollutants into value-added compounds: ammonia (NH3) via nitrate reduction (NO3-RR) and ethylene (C2H4) via carbon dioxide reduction (CO2RR). The first half of this work deals with the design and engineering of Cu-Zn alloy electrocatalysts for efficient NO3-RR. Tuning the alloy composition and surface nanostructure …

Rapid-Prototyping Nanofabrication: Lcd-Based Projection Lithography And Physical Vapor Deposition, Sabeel Saleem Mohammmed

University Honors Theses

The semiconductor industry's continued growth, driven in large part by demand for artificial intelligence hardware, has highlighted the need for greater workforce development in regions adjacent to major fabrication centers like Oregon's Silicon Forest. This capstone project lays the groundwork for a small scale and student led semiconductor fabrication lab at Portland State University by demonstrating two of the core steps in chip manufacturing: photolithography and thin film deposition. Rather than relying on conventional fixed reticles, this work explores a unique, low cost approach to patterning that uses an ultraviolet-compatible liquid crystal display (LCD) as a programmable reticle, allowing arbitrary …

Investigation Of Portland Limestone Cement Blended With Biochar From Downdraft Gasification: Hydration Kinetics, Microstructure, Rheology, And Performance Mechanisms, Ugochukwu Ewuzie, Paul C. Ani, Abdulkareem O. Yusuf, Joseph D. Smith, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

The widespread adoption of Portland Limestone Cement (PLC) in U.S. concrete production has necessitated research into commercially available supplementary cementitious materials (SCMs) for formulating high-performance, low-carbon blended binders with PLC. This study investigated the influence of biochar (BC) in biochar-PLC composites (CBCs), focusing on hydration kinetics, microstructure, rheology, pore-solution chemistry, compressive strength, and the underlying mechanisms. Biochar was produced via downdraft gasification at 850 °C and incorporated into PLC at 5, 7, and 10% substitution by mass. Isothermal calorimetry and hydration data modeled using the Knudsen equation revealed that BC retarded early hydration but improved hydration degree and later-age heat …

Fairlinked: Data Fairification Tools For Materials Data Science, Van D. Tran, Brandon Lee, Ritika Lamba, Henry Dirks, Quynh D. Tran, Balashanmuga Priyan Rajamohan, Ozan Dernek, Laura S. Bruckman, Yinghui Wu, Erika I. Barcelos, Roger H. French

Student Scholarship

FAIRLinked is a software package created to support the FAIRification of materials science data, ensuring proper alignment with FAIR principles: Findable, Accessible, Interoperable, and Reusable. It is built to be compatible with MDS-Onto, an ontology designed to capture the semantics of various types of materials data, enabling integration and sharing across different research workflows. The package is subdivided into three subpackages: InterfaceMDS, RDFTableConversion, and QBWorkflow. The first subpackage, InterfaceMDS allows users to search for terms using either string search or various filters, explore different domains and subdomains, and add terms to MDS-Onto. RDFTableConversion is used for serialization and deserialization of …

Quantum And Conventional Informatics Studies Of Synthesis Energetics And Defect Formation In Nitride Crystal Epitaxy, Andrew Steven Messecar

Dissertations

Machine learning is a valuable approach for the processing and analysis of complex information. By estimating relationships from recorded data, machine learning methodologies can be effective strategies for pattern recognition, enabling investigations and technological applications based thereon. The potential for improved understanding of high-dimensional data has drawn interest towards machine learning from across the sciences, including the research and development of new and improved material systems. In the context of experimental materials research, much of the reported efforts to incorporate machine learning into conventional practice have been primarily focused on either the enhanced analysis of characterization experiment data or the …

Characterization Of The Thermally Driven Red Hue Effect In Coated And Uncoated Concrete Systems: Implications For Post-Fire Assessment In Wildland Urban Interface Communities, Juan C. Palominos Jr

Master's Theses

The increasing frequency and intensity of Wildland-Urban Interface (WUI) wildfires, such as the destructive 2025 Pacific Palisades Fire that destroyed over 6,000 structures, have underscored the urgent need for rapid post-fire safety assessment methodologies. This study sought to quantitatively characterize the Thermally Driven Red Hue Effect (TRHE), a unique, irreversible color shift observed in architectural coatings and concrete substrates, to determine its reliability as a permanent visual record of thermal exposure. Concrete substrates were formulated with three distinct coarse aggregates: gold granite (14.7% Fe), red cinder (22.4% Fe), and green rock (33.6% Fe) and coated with a 20 PVC waterborne …

Thermally Induced Color Changes In Iron Oxide Pigments Used In Architectural Coatings, Han Diep

Master's Theses

The 2025 Palisades Fire was one of the most destructive wildfires in the history of Los Angeles, destroying thousands of structures and severely impacting the communities after. This widespread destruction demonstrated an urgent need for more effective wildfire prevention strategies. Architectural coatings do not only provide aesthetics and protection against environmental conditions but can also function as a thermal indicator when a fire breaks out. This study examines the thermally induced color transformation of iron oxide pigments, commonly used in earthtone paint, to provide information relevant to CAL FIRE for improved analysis of wildland-urban interface (WUI) fire behavior and mitigation …

Polarimetric Terahertz Imaging For The Measurement Of Birefringence In Plastic, Rachel Cohen

Theses

Birefringence offers a promising way to observe stress concentration in materials such as glass and plastic, and thereby to identify weaknesses. Polarimetric imaging can be used to measure the birefringence of material, so long as the material is transparent to the light being used for the imaging. In this research, 2D Terahertz imaging was investigated as a means of measuring the birefringence of plastics that are opaque to visible light but transparent to THz radiation, for the eventual purpose of analyzing the residual stress present. In order to do so, two separate terahertz cameras were characterized for potential use in …

A Generative Ai-Driven Computational Framework For Industry-Scale Discovery Of Novel Battery Materials, Joy Datta

Dissertations

The growing demand for sustainable, high-energy-density electrochemical storage has motivated the exploration of multivalent-ion batteries based on earth-abundant elements such as aluminum, calcium, magnesium, and zinc. While multivalent charge carriers offer higher theoretical energy density than lithium, their practical deployment is hindered by sluggish ion transport, strong ion-host interactions, and structural degradation of electrode materials. Identifying host materials that can reversibly accommodate multivalent ions while maintaining structural integrity remains a fundamental challenge. The dissertation develops a scalable, end-to-end computational framework that integrates density functional theory (DFT), machine learning (ML), and generative artificial intelligence (GenAI) to accelerate the discovery of next-generation …

Modulating Electronic Structure With Linearly Fused Pyrazine Units For High-Voltage And Stable Zinc-Organic Batteries Cathode, Min-Jian Zhao, Li-Bin Zhang, Jin-Tao Wang, Kun Ding, Hai-Mei Liu, Yong-Gang Wang

Journal of Electrochemistry

High-voltage n-type organic cathode materials are critical for constructing zinc-organic batteries (ZOBs) with high energy density and long cycle life. However, the intrinsically unfavorable electronic structures and relatively high LUMO energy levels of most n-type materials often lead to sluggish kinetics, high solubility, and suboptimal discharge voltages (< 0.8 V). Here, we design a small molecule, quinoxalino[2’,3’:5,6]pyrazino[2,3-f][1,10]phenanthroline (DPQP), as a ZOB cathode by introducing locally electron-deficient motifs into the conjugated backbone of aromatic compounds. The linearly fused pyrazine units extending the pyrazine–benzene framework effectively optimize the electronic structure, thereby significantly enhancing the discharge voltage. Meanwhile, the expanded π-conjugated plane suppresses dissolution and accelerates charge-transfer kinetics. Benefiting from these features, the DPQP electrode exhibits an exceptional increase in average operating voltage from 0.61 V to 1.07 V (vs. Zn²⁺/Zn) at 0.1 A·g^–1, with an overpotential of only 140 mV. Notably, no discernible voltage decay occurs as the current density increases, indicating rapid and highly reversible redox kinetics. Furthermore, the DPQP cathode delivers outstanding cycling stability, maintaining over 2000 h of continuous operation at 0.1 A·g^{–1 …}

(Co,Ni,Mn,Cu,Zn)O High-Entropy Oxide Nanotubes As Efficient Bifunctional Electrocatalyst For Oxygen Evolution And Hydrazine Oxidation Reactions, Pan-Yan Chen, Wan-Wan Wu, Heng Bian, Wei-Wei Li, Xin-Sheng Zhao, Lu Wei

Journal of Electrochemistry

High-entropy oxides (HEOs) present significant scientific challenges in both design and synthesis due to their multielement and high-entropy nature, which involves complex combinations of multiple metal cations and oxygen anions, typically arranged in equimolar ratios to achieve structural stability. Herein, one-dimensional (Co,Ni,Mn,Cu,Zn)O high-entropy oxide nanotubes (HEO-NTs) are fabricated by means of a gradient electrospinning strategy with a tailored polyvinyl alcohol (PVA) molecular weight distribution and controlled pyrolysis. Benefiting from the HEO features and the synergistic effect of multicomponent sites, the as-synthesized (Co,Ni,Mn,Cu,Zn)O HEO-NTs exhibit exceptional bifunctional electrocatalytic activity for the oxygen evolution and hydrazine oxidation reactions (OER/HzOR). This study offers …

An Analytical Framework For Quantifying Urban And Community Resilience To Natural Hazards From Cell-Phone Gps-Location And Traffic-Flow Data, Georgios Chatzikyriakidis

Civil and Environmental Engineering Theses and Dissertations

Urban areas are increasingly exposed to natural hazards while accommodating a growing share of the global population, yet a consistent science-based framework for quantifying urban and community resilience remains lacking. This dissertation develops a physics-based analytical framework grounded in statistical mechanics and the quantitative theory of Brownian motion. A city is conceptualized as a complex medium in which citizens move analogously to Brownian particles within a viscoelastic environment, influenced by socioeconomic interactions and infrastructure functionality.

A central premise is that urban resilience, interpreted as engineering resilience (an outcome), can be quantified through a single metric: the mean-square displacement MSD=⟨r²(t)⟩, of …

Surface Directed Microwave Assisted Fabrication Of Znmn2o4 And Its Composite As Anode Materials For Lithium Ion Battery, Anirudh Singh

Electronic Theses & Dissertations

The Lithium-ion batteries (LIBs) are widely utilized in portable electronics and electric/hybrid electric vehicles. However, the limited theoretical capacity of graphite (372 mA h g⁻¹) restricts further advancements. In our recent work, a series of ZnMn₂O₄ materials with various additives were synthesized using the microwave reaction method and evaluated as anodes for LIBs. Additives such as 2-methylimidazole (2MIM), polyvinyl alcohol (PVA), and cetyltrimethylammonium bromide (CTAB) were employed to prepare ZnMn₂O₄ with distinct morphologies. Our findings revealed that ZnMn₂O₄  with pure phases was achieved when 2MIM and CTAB were used as additives. …

Brine Solidification And Metals Sequestration Using Lignocellulosics, Frank Kvietok

World of Coal Ash Proceedings

Coal ash has historically been used as a convenient, on-site solidification material for brines generated from flue gas desulfurization at power plants. As alternate utilization scenarios are developed for coal ash, lignocellulosic (wood-based) sorbents can serve as a highly efficient substitute for the solidification process. Results will be shared for a variety of different brine types: thermally reduced, thermally reduced and neutralized, and reverse osmosis. In addition to solidification performance, which demonstrated a 3-4x mass of liquid vs mass of sorbent factor, studies were conducted to quantify the strength of binding to the wood-based sorbent for a broad range of …

Practical Guidelines For Pump Testing Of Ccr: Workflow, Design, And Lessons Learned., Nathanial Keller, Brian Hennings, Vic Modeer, Katie Moran

World of Coal Ash Proceedings

This session presents a streamlined approach for pump testing of coal combustion residuals (CCR) to maximize hydraulic information with limited well installations, variable pumping rates, and short tests. Pre-test forward modeling identifies well offsets (typically 5–10 ft) and test durations (~2–6 hours) to yield measurable and analyzable drawdown at observation wells despite low pumping rates. Field execution consists of short step-drawdown testing to evaluate well specific capacity and select pumping rates for a constant rate test with one or more observation wells. Test results facilitate analysis of transmissivity and storativity of the CCR. Applied at two Midwestern sites with different …

Simplified Approximate Procedure For Assessing The Implications Of Updated Usgs Seismic Hazard Models On Seismic Stability Assessments Of Ccr Impoundment Facilities, Nick Mcclung, Matt Bishop, Adrian Pena-Iguaran, Seda Gokyer-Erbis

World of Coal Ash Proceedings

Selection of appropriate seismic design ground motions remains a key challenge for seismic stability assessments of coal combustion residual (CCR) impoundment facilities, particularly where regulatory guidance does not specify a required hazard model. This paper examines the implications of using Uniform Hazard Spectra (UHS) derived from the 2014 versus the 2018 U.S. Geological Survey (USGS) National Seismic Hazard Model (NSHM) for seismic amplification and stability evaluations of the Tennessee Valley Authority (TVA) Widows Creek Fossil (WCF) Plant CCR Management Units. The 2018 NSHM incorporates updated understanding of seismicity in the central and eastern United States and generally predicts higher ground …

Integrating Advanced Geochemical Workflows With Modern Statistical Tools To Improve The Decision-Making Process At Ccr Sites, A Case Study, Glenna Thomas

World of Coal Ash Proceedings

While statistical assessment provides the foundation for CCR compliance reporting, incorporating a holistic geochemical framework transforms statistics from a compliance requirement into a powerful predictive tool. Strategic geochemical insight established the basis of understanding needed to support successful statistical approaches and to ensure that statistical outcomes reflect actual groundwater behavior. Whether it is trend analysis, delineating source mechanism, or updating geochemical conceptual site models (GCMs), geochemical context provides the technical foundations for statistical outputs and methods. A continuously refined GCSM enhances the ability to anticipate how groundwater chemistry should evolve, improving interpretation and predictive capability. This allows practitioners to understand …

Before The Limit Hits: Lessons From A Proactive Construction Air Monitoring Program, Brian Egan, Nicholas Golden, Wendy Depp

World of Coal Ash Proceedings

This presentation describes a comprehensive air monitoring program designed to protect workers and nearby neighborhoods during ash pond closure work. The program uses three main components: project (or boundary) monitoring at the site perimeter to track dust near the project boundaries, work area monitoring placed near active construction zones, and personal sampling on individual workers at regular intervals. Together, these approaches provide data on both community impacts and worker exposures, helping the team respond quickly when levels approach action limits. The Teams actions prior to exceedance of regulatory limits has helped prevent exposures. The talk will explain how monitors are …

Monitored Natural Attenuation Evaluation And Additional Characterization Of A Ccr Unit Lithium Groundwater Plume, Matt Barickman, Adam Piestrzeniewicz Pg

World of Coal Ash Proceedings

Monitored Natural Attenuation (MNA) refers to the reliance on natural attenuation processes (within the context of a carefully controlled and monitored site cleanup approach) to meet groundwater protection standards (GPS) for a CCR unit within a reasonable time frame (USEPA, 1999). MNA is being evaluated as an adaptive management strategy for a CCR unit groundwater plume with statistically significant lithium concentrations above GPS, though with little risk of offsite migration. A previous MNA evaluation was performed for the lithium plume following the United States Environmental Protection Agency (USEPA) “tiered lines of evidence approach” (USEPA, 2015), which determined that there were …

Establishing Groundwater Monitoring Systems Under The Legacy Rule: A Systematic Approach For Utilities, Chris Hoglund

World of Coal Ash Proceedings

The USEPA’s Legacy CCR Rule introduces new requirements for establishing groundwater monitoring systems at Legacy Surface Impoundments (LSIs) and Coal Combustion Residual Management Units (CCRMUs). These requirements present unique challenges for electric utilities, particularly at inactive or historically operated facilities where subsurface data are limited and CCR units may have nontraditional configurations such as linear roadways, elongated embankments, or distributed disposal areas. Utilities must also determine how best to apply single-unit or multi-unit monitoring approaches, integrate newly regulated units into existing monitoring networks, and align monitoring system design with planned closure strategies. This presentation outlines a systematic, defensible framework to …

Risk Evaluation Of Linear Coal Combustion Residual Management Unit (Ccrmu) Fills, Qian Zhang, Andrew Bittner, John Kondziolka, Masoud Arshadi

World of Coal Ash Proceedings

In 2024, the US Environmental Protection Agency (US EPA) established new regulations for coal combustion residual management units (CCRMUs), defined as coal combustion residual (CCR) deposits placed on power plant properties outside of landfills or surface impoundments. US EPA supported the rulemaking with modeling-based risk analyses and established regulatory requirements based on fill size. Linear CCRMU, such as backfill along pipelines or haul roads, have individual segments that may be composed of a small amount of mass below the threshold for regulation, but the cumulative mass over the full linear feature extent may exceed regulatory thresholds. This study applies US …

Application Of Mine Tailings Flow Failure Assessment On Ccr, Zachary Fallert

World of Coal Ash Proceedings

A new geotechnical stability analysis method has been implemented for a CCR surface impoundment to aid in design for temporary cut slopes and final closure grades. Conditions have come to light after significant tailings dam failures occurred across the globe, specifically those exhibiting flow failures (i.e. failures in which tailings behave a liquid and flow out of the facility). These failures have come under intense scrutiny as the failures pose significant risk to public safety and the environment and have been observed in CCR. Additionally, static liquefaction has arisen as another potential but less well understood causative mechanism. As the …

Lessons Learned: Commissioning An Fgd Wastewater Treatment System, Bella Triolet, Mckale Grant, Louis Manigault

World of Coal Ash Proceedings

Stantec recently supported commissioning a flue gas desulfurization (FGD) Wastewater Treatment System in accordance with the 2020 Environmental Protection Agency (EPA) Effluent Limitations Guidelines (ELG) Rule, which requires that coal fired power plants meet their more stringent requirements by December 31, 2025. With the addition of the 2024 EPA ELG Rule, coal fired power plants will now be expected to move to zero liquid discharge (ZLD) systems or permanently cease coal combustion by 2034. Due to this change, it is likely that coal fired power plants will be looking to design and install ZLD systems within the next decade. While …

Risk Evaluation Of Linear Coal Combustion Residual Management Unit (Ccrmu) Fills, Qian Zhang, Andrew Bittner, John Kondziolka, Masoud Arshadi

World of Coal Ash Proceedings

In 2024, the US Environmental Protection Agency (US EPA) established new regulations for coal combustion residual management units (CCRMUs), defined as coal combustion residual (CCR) deposits placed on power plant properties outside of landfills or surface impoundments. US EPA supported the rulemaking with modeling-based risk analyses and established regulatory requirements based on fill size. Linear CCRMU, such as backfill along pipelines or haul roads, have individual segments that may be composed of a small amount of mass below the threshold for regulation, but the cumulative mass over the full linear feature extent may exceed regulatory thresholds. This study applies US …

Site Characterization, Design, Permitting, And Construction For Clean Closure Of A Small But Challenging Legacy Ccr Disposal Impoundment, John Garten, Bob Baker, Lee Lenhart

World of Coal Ash Proceedings

The Lay of Land Area (LOLA) is a 10-acre (40,468 square meters) legacy disposal impoundment containing approximately 55,000 cubic yards (42,000 cubic meters) of sluiced coal combustion residuals (CCRs) produced during startup operations of a former fossil plant. Most of its perimeter is bounded by water, with a river to the north and a cooling water lake to the south. The entire area lies within a 100-year floodplain, is heavily forested, and groundwater is typically encountered within a few feet of the existing ground surface. As part of an overall CCR closure-by-removal and ash beneficiation program, planning, design, permitting, and …

Trimble County Pond Closures, Steven Turner, Shanti Montgomery

World of Coal Ash Proceedings

The Trimble County Closure Project is a 5-year project to close the 40-acre (161,900 square meters) Gypsum Storage Pond (GSP) through closure-by-removal and the 100-acre (404,700 square meters) Bottom Ash Pond (BAP) through closure-in-place in accordance with coal combustion residual (CCR) Rule. The excavated gypsum from the GSP was “Beneficially Reused” to fill the BAP to the prescribed grade for drainage through a monitored outfall to the adjacent creek. The daily plant produced CCRs of fly ash, bottom ash, and gypsum were also used for four years to supplement the filling of the BAP as well as several onsite soil/rock …