Digital Commons Network^™

Comparative Evaluation Of Gating Systems In Femnal Castings, K. Balasubramanian, Laura Bartlett, M. Xu

Materials Science and Engineering Faculty Research & Creative Works

To understand the efficiency of gating systems, four systems, namely AFS styled pressurized system, AFS styled non-pressurized system, naturally pressurized system with a side riser and a naturally pressurized system with a top riser, were studied. The naturally pressurized systems were provided with overflows which collected the incoming metal swirl while the pressurized and non-pressurized systems had runner wells. Parameters like velocity of metal flow, air entrapment, microporosity and Niyama criterion were considered, and a design was developed with a common pouring basin using solidification software. Two molds were 3D printed using carbonitride sand, and steel of composition Fe-29Mn-8.2Al-0.91C-0.88Si-0.49Mo was …

Microstructure And Properties Of Oxide Dispersion-Strengthened Alloys, Ertugrul Demir, Seung Min Ha, Anish Ranjan, Xingshuo Zhang, Aaron Penders, Mukesh Bachhav, Xiaochun Li, Lin Shao, Alexander Demblon, Haiming Wen, Enrique Lavernia

Materials Science and Engineering Faculty Research & Creative Works

Oxide dispersion-strengthened (ODS) alloys are a critical class of structural materials for extreme environments, owing to their unique combination of high-temperature strength, thermal stability, and radiation tolerance, enabled by a very high density of nanoscale oxide dispersoids. These features make ODS alloys attractive for advanced nuclear systems, aerospace applications, and other harsh-service conditions where conventional alloys rapidly degrade. Despite decades of development, key challenges remain in understanding how nanoscale oxides interact with matrix microstructures, alloy chemistry, and irradiation-induced defects to control macroscopic performance. This review provides a focused, mechanism-based synthesis of the microstructural features that govern the properties of ODS …

Overcoming Resolution Vs. Throughput Trade-Offs In Ceramic Material Extrusion Additive Manufacturing Via Viscoelastic Filament Stretching, Abid H. Rafi, David W. Lipke, Jeremy L. Watts, Gregory E. Hilmas, Ming C. Leu

Materials Science and Engineering Faculty Research & Creative Works

Fabricating large, monolithic ceramic parts using material-extrusion additive manufacturing remains challenging due to difficulty maintaining uniform moisture content during printing, which can lead to drying-induced defects such as warping and cracking, especially as part size and print time increase. Fabricated parts have trade-offs among print resolution, high throughput, and structural fidelity. Our study has shown that increasing the ratio of nozzle traverse speed vs. material extrusion speed increases filament stretching in viscoelastic ceramic paste, helping to overcome the trade-offs between resolution and throughput. Using aqueous ZrB2–SiC (70/30 vol.%) as a representative ultra-high temperature ceramic paste, rheological characterisation revealed viscoelastic yield-stress …

N-Radii Approach For Multi-Scale Characterization Of Graphite Shape In Cast Iron, Simon N. Lekakh, Laura Bartlett

Materials Science and Engineering Faculty Research & Creative Works

Knowledge of multi-scale particle macro-shape and micro-surface topology is critical in many technical disciplines. Specifically, quality assessment of the shape of the graphite phase in cast irons is essential for day-to-day metal casting operations. Common methods for evaluating particle macro-shape have several drawbacks, often resulting in underestimation of sharp corners and surface texture. In this article, a method based on plotting n-radii from the center of mass to the perimeter and computing multi-scale topological characteristics is described and tested. Parametric tests, involving variations in the number of n-radii and image resolution, were performed to optimize the test parameters. The method …

Modeling Of Transformation Temperatures In Cast Martensitic Stainless Steels-Ca6nm: Effects Of Composition, Heating Rate, And Grain Size, Ugochukwu Agbedo, Mario Buchely, Laura Bartlett, Caelan Kennedy

Materials Science and Engineering Faculty Research & Creative Works

Accurate prediction of the critical transformation temperatures Ac1 and Ac3 is one of the essential factors in the heat treatment of CA6NM cast martensitic stainless steel. In this study, the influence of alloy composition, heating rate, and prior austenite grain size on the critical temperatures was quantified using dilatometric measurements and statistical modeling. Six heat treatment conditions produced prior austenite grain sizes ranging from ~75 to 247 µm. Experimental results showed that grain size variations produced only minor changes in Ac1 and Ac3, indicating a weak dependence of transformation temperatures on prior austenite grain size within the investigated range. In …

Multiphysics Simulation And Experimental Validation Of Phase Transformation And Hardness In Jominy End-Quenched Low-Alloy Steels, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. A. Athavale, A. Kumar

Materials Science and Engineering Faculty Research & Creative Works

High-volume industrial continuous hot-rolled steel heat treatment processes involve sophisticated multi-phase modeling. The performance of a given process can be optimized by coupling phase transformation kinetics with the cooling conditions of the process. This study develops a multiphysics model to simulate an intensive quenching process for steel, which is inherently transient and highly dependent on numerous parameters. The simulated object was a Jominy end-quenched specimen geometry using two commercial steels, AISI 4130 and AISI 4140, with the goal of transferring a verified methodology to the heat treatment process for industrial heavy-section products (bars, slabs). The simulation employs thermal, mechanical, and …

Effect Of Complex Alloying Elements On Oxide Scale Formation And Water-Jet Descaling Performance On Continuously Cast Low-Carbon Steels, Tochukwu P. Ojiako, Tsvetkov Dmitry, Mario Buchely, Haiming Wen, Simon N. Lekakh, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

The formation and evolution of oxide scale in contact with mold flux during continuous casting, subsequent reheating, and hydraulic descaling are strongly governed by steel chemistry. To elucidate the effect of complex alloying elements (Si, Mn, and Cr), two industrially produced continuously cast low-carbon steel grades for manufacturing stamped parts (a base and alloyed steel grade) were investigated. The objective was to determine how alloying elements influence oxidation behavior, scale morphology, interfacial adhesion, and water-jet descaling efficiency. Continuously cast slab specimens were subjected to controlled thermal and atmospheric oxidation cycles simulating multistage industrial practice. Three initial surface conditions (industrial as-cast, …

Elevated Temperature Flexure Behavior Of Continuous Carbon Fiber Reinforced Zrb2–Zrsi2 Ultrahigh Temperature Ceramic Matrix Composites, Jacob Stacy, Aaron Ginsparg, Jason Lonergan, Jeremy Watts, Gregory Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Ultrahigh temperature ceramic matrix composites (UHTCMCs) were fabricated from unidirectional prepreg tapes consisting of a matrix of ZrB₂ with 5, 10, and 15 vol.% ZrSi₂ additions and continuous polyacrylonitrile carbon fibers and were densified at 1600°C in a hot press. The relative matrix densities ranged from 88% to 93% with interlayer spacings of ∼72 µm and fiber volume fractions between 30% and 36%. Phenolic resin additions were utilized to react with ZrSi₂ acting as a transient sintering aid to form ZrC and SiC phases. Elastic moduli of the UHTCMCs decreased with increasing temperature during 4-pt flexure testing. …

Quantitative Grain Structure And Texture Analysis Of Hot-Pressed Zrb2 Via 3d Ebsd, Randi Swanson, Michael Chapman, Yue Zhou, Ashley Hilmas, Lisa Rueschhoff, Michael Uchic, William Fahrenholtz, Scott J. Mccormack

Materials Science and Engineering Faculty Research & Creative Works

Understanding and controlling the grain structure of ZrB₂ is critical for optimizing its mechanical and thermal performance in high-temperature applications. Fully dense ZrB₂, densified by hot pressing at 2150˚C and 32 MPa, was analyzed in three dimensions using electron backscattered diffraction, electron and optical microscopy, and mechanical polishing serial sectioning. Grain size followed a gamma distribution, with extreme deviations observed only in the largest 0.1% of grains. Large grains exhibited plate-like morphologies, with the shortest-to-longest axis ratio converging to ∼0.4 as grain volume increased. This work revealed a crystallographically controlled growth mechanism orthogonal to [0001] that is …

Simulated Lunar Gravity Testing Of A Magnetic And Electrostatic System For Beneficiating Lunar Regolith, Blake A. Coffman, Gabriel Porter, Lindsay Manteufel, Mitchell Cottrell, Jeffrey D. Smith, David J. Bayless, William Shonberg, Frank D. Han, Fateme Rezaei, Kirby Runyon

Materials Science and Engineering Faculty Research & Creative Works

We present the design and testing of a lunar regolith beneficiation device that utilizes magnetic and electrostatic separation methods to concentrate desired minerals by removing unwanted material, such as the mineral anorthite, from bulk lunar regolith. The beneficiated materials would have value for downstream in-situ resource utilization (ISRU) processes such as metal extraction, oxygen extraction, and metal oxide additive manufacturing processes. The apparatus uses a dual-strength magnet system with N52 and N42 neodymium magnets to separate particles by magnetic susceptibility. The electrostatic separation system, which acts like a sieve, sorts the regolith simulant by particle size using a single-phase 50% …

The Effects Of Mold Flux Contamination On Oxide Scale Formation And Hydro-Descaling Efficiency During Steel Processing, Tochukwu Princewill Ojiako, Richard Osei, Mario Buchely, Haiming Wen, Simon Lekakh, Ronald O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Oxide scale formation during thin-slab continuous casting has a complex structure, which is influenced by mold flux contamination, that modifies interfacial reactions during solidification, subsequent reheating, and descaling. While individual aspects of the oxidation behavior of carbon steel have been previously examined, the synergetic effects of mold flux contamination during continuous casting and subsequent reheating on scale modification and the efficiency of hydraulic descaling remain inadequately studied. This study quantitatively examines the effect of flux composition on oxide scale evolution, adhesion, and hydraulic removal in low-carbon steel under simulated industrial conditions. Slab samples with as-cast, cleaned, and flux-coated surfaces were …

Large Language Scholarship, Alan Rozenshtein, Kevin Frazier

Articles

Generative AI isn’t just coming for the legal academy—the era of what we call “Large Language Scholarship” is already here. Law professors are using AI to write articles in weeks rather than months. Law reviews face an unprecedented deluge of AI-polished submissions. And the judges who increasingly lean on AI to help draft their own opinions will soon struggle to distinguish genuine insight from sophisticated imitation. Yet, existing scholarship offers only fragmented responses, trapped in misguided debates about plagiarism and disclosure while missing the full scope of the unfolding transformation.

This Article provides the first comprehensive analysis of how generative …

Quantum Critical Behavior Of Diluted Quasi-One-Dimensional Ising Chains, Logan Sowadski, Thomas Vojta

Physics Faculty Research & Creative Works

(Formula presented.) (Formula presented.) is a unique magnetic material. It features bulk 3D magnetic order at low temperatures, but its quantum critical behavior in a magnetic field is well described by the 1D transverse-field Ising universality class. This behavior is facilitated by the structural arrangement of magnetic (Formula presented.) ions in nearly isolated zig-zag chains. In this work, we investigate the effect of random site dilution on the critical properties of such a quasi-1D quantum Ising system. To this end, we introduce an anisotropic site-diluted 3D transverse-field Ising model. We find that site dilution leads to unconventional activated scaling behavior …

Emergent Spin Fluctuation And Structural Metastability In Self-Intercalated Cr1+Xte2 Compounds, Clayton Conner, Ali Sarikhani, Theo Volz, Mathew Pollard, Mitchel Vaninger, Xiaoqing He, Steven Kelley, Jacob Cook, Avinash Sah, John Clark, Hunter Lucker, Cheng Zhang, Paul Miceli, Yew San Hor

Physics Faculty Research & Creative Works

Intercalated van der Waals (vdW) magnetic materials host unique magnetic properties due to the interplay of competing interlayer and intralayer exchange couplings, which depend on the intercalant concentration within the van der Waals gaps. Magnetic vdW compound chromium telluride, (Formula presented.), has demonstrated rich magnetic phases at various Cr concentrations, such as the coexistence of ferromagnetic and antiferromagnetic phases in (Formula presented.) (equivalently, (Formula presented.)). The compound is created by intercalating 0.25 Cr atom per unit cell within the van der Waals gaps of (Formula presented.). In this work, we report a notably increased Curie Temperature and an emergent in-plane …

Relativistic And Recoil Corrections To Light-Fermion Vacuum Polarization For Bound Systems Of Spin-0, Spin-1=2, And Spin-1 Particles, Gregory S. Adkins, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

In bound systems whose constituent particles are heavier than the electron, the dominant radiative correction to energy levels is given by light-fermion (electronic) vacuum polarization. In consequence, relativistic and recoil corrections to the one-loop vacuum-polarization correction are phenomenologically relevant. Here, we generalize the treatment, previously accomplished for systems with orbiting muons, to bound systems of constituents with more general spins: spin-0, spin-1=2, and spin-1. We discuss the application of our more general expressions to various systems of interest, including spinless systems (pionium), muonic hydrogen and deuterium, and devote special attention to the excited non-S states of deuteronium, the bound system …

A Case Of Acquired Amusia And Misophonia Following Right Temporal Resection, Emily R. Dappen, Joel I. Berger, Amy M. Belfi, Joel Bruss, Timothy D. Griffiths, Alexander J. Billig, Ariane E. Rhone, Kirill V. Nourski, Daniel Tranel, Brian J. Dlouhy

Psychological Science Faculty Research & Creative Works

Background: Our perception of the auditory world allows us to enjoy the richness of music and communicate effectively with others. These everyday processes are disrupted in conditions such as amusia, an inability to perceive music accurately, and misophonia, an intense emotional reaction to common sounds produced by others. We describe a case of acquired, concurrent amusia and misophonia in a 21-year-old right-handed woman following a right posterior insula, posterior temporal, supramarginal cortex, and sensory cortex resection for the treatment of drug-resistant epilepsy. Methods: The patient participated in interviews between 4–8 months post-resection. She completed an extensive testing battery designed to …

Teaching Effectiveness On Secondary Mathematics: Evidence From Pisa—Shanghai-China, Ting Shen

Psychological Science Faculty Research & Creative Works

Educational researchers and policymakers around the world have a strong interest in understanding the underlying reasons for the remarkable academic achievement of Chinese students in the Programme for International Student Assessment (PISA). Although teachers have a significant impact on student achievement, empirical evidence on teaching effectiveness in the Chinese education system has been scarce. This study uses the PISA 2012 Shanghai-China data and employs both multilevel models and quantile regression models to investigate effective teaching factors and their differential effects for students at different mathematics achievement levels. The results reveal the importance of cognitive activation and disciplinary climate as consistent, …

Five Tensions Of Artificial Intelligence Adoption For Organ Allocation: Applying The Technology–Organization–Environment Framework, Amaneh Babaee, Daniel Burton Shank, Casey I. Canfield, Joely Grace Hall, Krista L. Lentine, Henry Randall, Mark Schnitzler

Psychological Science Faculty Research & Creative Works

Background: The US organ transplantation system is pursuing modernization of the allocation process through the integration of new technologies such as artificial intelligence (AI). However, the legal and ethical issues within the transplantation industry are still of concern. Objective: We explore the opportunities and challenges for Organ Procurement Organizations (OPOs) to adopt AI. The US organ transplant system is a highly regulated industry yet open to innovation. Methods: Ten structured interviews were conducted with OPO representatives using the Extended Technology, Organization, Environment (TOE) framework. Results: Overall, we identified five core tensions in AI adoption: (1) misconceptions, (2) approach to training, …

Character Judgements Of Rap Music Fans, Kaila C. Putter, Dan J. Miller, Amy M. Belfi, James Rees, Amanda E. Krause

Psychological Science Faculty Research & Creative Works

Extending Fischoff, we used vignettes to examine people's perceptions of a hypothetical rap fan accused of murder. Study 1 (N = 300) used a 2 (murder accusation) x 2 (inclusion of rap lyrics) x 2 (fan gender) experiment, asking participants to judge how capable of murder and sexually aggressive they found the fan. The presentation of lyrics and murder accusation were associated with the fan being more capable of murder, while rap lyrics and participants' rap attitudes were associated with the fan being more sexually aggressive. Thematic analysis revealed that, in conditions containing both the lyrics and the murder accusation, …

Structural And Intersectional Factors In Full Retirement: Insights For Black Men, Waleed Sami

Adultspan Journal

This interview centers the full retirement experience of Anthony Crawford. This perspective highlights the complex interplay between social determinants, intersectional identity, the psychology of working, and social class/social mobility, as key factors in his lived experiences. The relationship between structural factors and interpersonal factors continues to be a growth edge in counseling, as counselors frequently report lack of knowledge or comfort in their relationship with counseling. This interview seeks to fill the gap and demonstrate a concrete way to develop clinical insights. The full interview is transcribed and provided, along with practical and research implications for counselors working with populations …

A Method For Determining A True National Statistical Distribution Of Building Element U-Values And Its Application To A Dataset Underpinning A Building Stock Energy Model, C. Ahern, Bernard Enright, A. Griffin, B. Norton

Research Outputs: 2025-Present

The presence of default U-values in Energy Performance Certificate (EPC) databases disrupts the natural variability in measured U-value distributions. Default values, often used by assessors when empirical data is unavailable, introduce deterministic artefacts into datasets, creating artificial peaks that obscure underlying statistical patterns. This study examines the impact of these default values and identifies appropriate statistical models – Lognormal, Gamma and Normal – for measured U-values in Ireland’s national EPC dataset, comprising 463,582 dwellings. Lognormal and Gamma distributions aligned better with the central peaks, while the Normal distribution more accurately captured the tails. Although no single distribution perfectly fits the …

A Practice-Led Exploration Into The Melodic And Rhythmic Techniques Of Kenny Kirkland, Reuben Cope

Theses : Honours

Kenneth David Kirkland (Kenny Kirkland) was one of the most in demand and influential jazz pianists of the late twentieth century. Highly regarded among peers and critics, Kirkland worked extensively with numerous jazz luminaries and was best known for his work with both Wynton and Branford Marsalis, as well as with the pop star Sting.

This study aims to advance my ability as an improviser to access and utilise the melodic and rhythmic techniques featured within the improvisations of Kenny Kirkland. This aim was guided by observed limitations in my ability to shape the arc of my improvisations to push …

The Rise Of Global Collaboration In China Policy Research: Evidence From Bibliometric Network Analyses, 2000–2025, Yu Xiao, Aaron Ley, Ping Xu

Political Science Faculty Publications

This study examines the evolution of China policy research and its growing role in global policy scholarship. Using bibliometric and social network analyses of 326 articles published in 20 high-impact political science journals from 2000 to 2025, we trace the field’s expansion, identify key thematic concentrations, and document the emergence of robust international collaboration patterns. Cross-national co-authorship networks reveal a clear transition from a fragmented, Western-centered structure to a dual-hub system anchored by Mainland China and the United States, while institution-level networks show that leading Chinese universities have become central collaborators and Hong Kong institutions continue to serve as critical …

Evolving Contexts And Diverging Strategies: Federalism And The Politics Of Immigrant Welfare Exclusion In The Us, Ping Xu, Ling Zhu, Sebastian Ege

Political Science Faculty Publications

The intersection of immigration and welfare has taken a central stage in the politics of social policy and garnered increasing scholarly attention in welfare politics research. While prior research has examined how immigration affects welfare support and welfare generosity in the US, less is known about the determinants of immigrant-related welfare policies. This paper investigates how state-level policymakers shape immigrant welfare policies in response to changing social and economic state contexts across the U.S. states from 2000 to 2020. Using data from the Urban Institute's Welfare Rules Database, we create a policy index of welfare inclusion of immigrants to track …

Governing Ai Without Agencies: Self-Regulatory Organizations And The Federal Backstop, Aram A. Gavoor

GW Law Faculty Publications & Other Works

Artificial intelligence is accelerating American innovation and strategic advantage. The governance task is to provide predictable compliance baselines that support scale and competitiveness while remaining workable under executive branch policy, statutory baselines, and the rules that now govern the administrative state. Congress remains slow and factional, and agencies face rising procedural and remedial constraints. Recent Supreme Court doctrine has reduced the administrative state’s interpretive and enforcement leverage. Regulated entities can challenge agency rules when those rules newly impose concrete harm, litigate statutory meaning without Chevron-style mandatory deference to agency statutory interpretations with limited exceptions, and invoke strengthened procedural safeguards in …

Deploying The “Trade Bazooka”: How The Anti-Coercion Instrument Reshapes Eu Public Procurement, Amanda Lythgoe, Christopher R. Yukins

GW Law Faculty Publications & Other Works

As trade disputes continue to batter the relationship between the U.S. and its partners in the European Union, a new countermeasure by the EU—the Anti-Coercion Instrument (ACI)—has emerged as a serious threat to trade flows, including in public procurement. Although formally framed as a trade-defense mechanism, the ACI is a legal instrument capable of addressing a broad range of economic coercion. Notably, although the ACI is presented as a means of deterrence and de-escalation, the ACI authorizes countermeasures that extend well beyond tariffs, and can severely restrict foreign firms’ access to EU public procurement markets. This article provides an historical …

Brief For International Law Scholars As Amici Curiae In Support Of Respondents, Cisco Systems, Inc. V. Doe I, William S. Dodge

GW Law Faculty Publications & Other Works

This amicus brief was filed with the U.S. Supreme Court on behalf of international law scholars in Cisco Systems, Inc. v. Doe I. The brief addresses whether claims for aiding and abetting violations of international human rights may be brought under the Alien Tort Statute. Part I argues that, under Sosa v. Alvarez-Machain (2004), whether aiding and abetting claims are actionable is determined by customary international law rather than U.S. domestic law. Part II argues that customary international law’s prohibition against aiding and abetting human rights violations meets the Sosa standard. Drawing on instruments establishing the Nuremberg tribunals, the International …

Two Heads Are Better Than One: Integrating International Law And Global Public Health Approaches To Firearm Violence To Promote Public Safety And Human Rights, Arturo J. Carrillo, Jonathan E. Lowy

GW Law Faculty Publications & Other Works

In his Advisory of June 25th, 2024, the U.S. Surgeon General, Vivek H. Murthy, declared firearm violence a public health crisis and presented a damning picture of the widespread deaths, injuries and trauma caused by gun violence in the United States. A critical feature of the firearm violence crisis in the United States that the Surgeon General did not expressly address in his report–or even mention–is the role of the manufacturers, distributors, and dealers of firearms, collectively referred to as “the gun industry.” It is an open secret that the U.S.-based firearm industry engages in manufacturing, marketing, distribution and sale …

Shrinkflation And Consumer Demand, Aljoscha Janssen, Johannes Kasinger

Research Collection School Of Economics

This study investigates shrinkflation—the practice of reducing product size while maintaining or slightly changing prices—in the U.S. retail grocery market. We analyze a decade of retail scanner data to assess the prevalence and patterns of product size changes across various product categories. Our findings show that approximately 1.92% of products have been downsized. When comparing total sales, product downsizing is more than five times as prevalent as upsizing. Product downsizing typically occurs without a corresponding decrease in price and is widespread across product categories. Consequently, consumers end up paying more per unit volume. We further find that consumers are more …

Childlessness And Health In Middle Age And Older Adulthood: Evidence From Singapore, Christine Ho, Dahye Kim, Rohan Ray, Bussarawan Teerawichitchainan

Research Collection School Of Economics

Health and well-being in mature adulthood are important concerns given the prevalence of individuals aging without children. We exploit two new instruments for childlessness— infertility and the number of childless siblings—and condition our analyses on a rich set of covariates including childhood health and financial status, to investigate the causal relationship between childlessness and health in middle age and older adulthood. Using a nationwide dataset of 1,500 Singaporeans aged 50 and above, we show that OLS underestimates the negativeeffects of childlessness on health. We find that childlessness leads to higher likelihood of poorer self-reported health and mental distress. The results …