Physical Sciences and Mathematics Commons^™

Characterizing The Unique Chemical Imprint Of On-Axis, Lower-Temperature Hydrothermal Flow To The Deep Ocean (Southern East Pacific Rise, 16.5°–18.0°S), Laura E. Moore, Randelle M. Bundy, Joseph A. Resing, Scott M. White, Tamara Baumberger, Peter N. Sedwick, Nathaniel J. Buck, Anson M. Antriasian, Isaac Keohane

Faculty Publications

In addition to high-temperature vents, lower-temperature flow (LTF) (< 300°C) is abundant along mid-ocean ridges and contributes globally-important fluxes of heat and water along with largely-unconstrained geochemical influences on the ocean. We examined the impact of on-axis LTF on the chemical composition of the overlying water column (< 40 m above seafloor) along the 16.5°–18.0°S sector of the ultrafast-spreading southern East Pacific Rise using autonomous underwater vehicle Sentry surveys and conductivity-temperature-depth rosette casts. LTF sites were typically spatially isolated from high-temperature systems and imparted unique chemical signatures to the overlying ocean. Water column samples impacted by LTF exhibited low particulate iron:sulfur ratios and high methane: total-dissolvable manganese ratios, whereas samples influenced by high-temperature venting exhibited opposite trends. We confirmed that LTF imparts a distinct and measurable chemical signature to the water column, independent from high-temperature vents. Isolated, on-axis LTF will be important to consider when assessing hydrothermal circulation impacts upon ocean biogeochemistry.

Impact Of Collodion Thickness On Fission Track Generation Within Lexan Employed For Nuclear Forensic Analyses, Ryan K. Chapman, Zachary P. Meisel, Abigail A. Bickley

Faculty Publications

We report results from a computational study of fission track damage within a Lexan substrate caused by ²³⁵U suspended within a collodion film of varied thickness. MCNP6.3 was used to model energy deposition and displacements per atom within a Lexan film coated by a film of collodion, located within the air-filled 6 inch dry tube of a TRIGA reactor. The collodion layer was varied between 20 and 100 μm thickness, resulting in an 8.8% difference in energy deposition and 12% difference in displacements-per-atom within the Lexan substrate. These findings indicate that collodion adhesive thickness has a moderate impact on …

Comparison Of Anomaly Detection Methods On Event-Based Vision Sensor Data In A High Noise Environment, Will Johnston, Anthony L. Franz, Shannon R. Young, Rachel Oliver, Zachary Theis, Brian Mcreynolds, Michael L. Dexter

Faculty Publications

Event-based vision sensors (EVSs) provide unique frequency analysis opportunities due to their event data output and high temporal resolution. Anomaly detection methods used in hyperspectral analysis can be used on the event frequency spectra to detect targets. However, the introduction of a strong, flickering interfering source can reduce the EVS sensitivity and obscure targets of interest. Previous work presented a method showing that targets could still be detected through an overwhelming source using frequency analysis, background suppression, and statistical filtering. This paper extends that research and compares the ability of five different eigenanalysis anomaly detection methods (principal component background suppression …

Psychosocial Mediators Of A Physical Activity And Dietary Intervention In Pregnant Women With Overweight Or Obesity, Meghan Baruth, Sarah Wilcox, Jihong Liu, Rebecca Schlaff

Faculty Publications

Background

Mediation analyses provide insight into both ‘pieces’ of the mediation chain; they allow us to look into the ‘black box’ that is behavior change. They allow researchers to better understand the ‘how’ of an intervention’s effects and/or the ‘why’ behind why an intervention worked or did not work. The lack of publications in pregnant populations highlights the need for additional studies to be conducted and published. The purpose of this study is to examine the psychosocial mediators of physical activity and dietary outcomes in a sample of pregnant women with overweight or obesity participating in the Health in Pregnancy …

Bgc-Argo Float Reveals Shifts In Nitrogen-Carbon Cycling In An Oxygen-Deficient Zone, Mariana B. Bif, Colette Kelly, Mark A. Altabet, Annie Bourbonnais, Claire Elbon, Edgart Flores, Alanna Mnich, Josh Plant, Kenneth S. Johnson

Faculty Publications

Oxygen-deficient zones are hotspots of marine fixed nitrogen loss, but the temporal dynamics of their microbial processes remain poorly resolved. Here we present a nearly three-year high-resolution record from a Biogeochemical Argo float in the Eastern Tropical North Pacific that captures a decline in nitrite concentrations, reflecting a shift in nitrogen redox balance. Using a stoichiometric mass-balance model, we quantify nitrogen transformations, including dissimilatory nitrate reduction to nitrite, denitrification, anammox, and nitrite oxidation, and their coupling to carbonate chemistry. The model shows that dissimilatory nitrate reduction to nitrite dominates nitrogen transformations, while denitrification and anammox vary over depth, biogeochemical transition, …

Synthesis Of Copper-Phenanthroline Complexes: A Solvothermal-Compatible Approach For The Exploration Of Metal Complexes, Yunping Zhoujin, Michael Anim Safo, Navindra Keerthisinghe, Mark D. Smith, Sophya Garashchuk, Hans Conrad Zur Loye

Faculty Publications

Inorganic–organic hybrid materials have been widely investigated for their applications in catalysis, optics, magnetism, and biomedicine. Copper halide complexes are of particular interest due to their structural diversity and physicochemical properties. Conventional crystal growth approaches, such as slow evaporation and hydro(solvo)thermal synthesis, typically require extended reaction times and often favor thermodynamically stable phases. In this study, we prepared ten copper-phenanthroline halide (X = Cl, Br, and I) complexes using both traditional hydrothermal reactions and microwave-assisted hydrothermal methods and obtained [CuI(C₁₂H₈N₂)₂][I₃], [C₁₂H₉N₂][CuI₂]·(H_{2 …}

Inferring The Breakdown Scales Of The Chiral Expansions For GA And MN, Andreas Ekström, Daniel R. Phillips, Lucas Platter, Matthias Schindler

Faculty Publications

We apply Bayesian inference to the order-by-order chiral perturbation theory (χPT) expansions for the axial-vector coupling constant g_A and the nucleon mass m_N, and thereby infer the scales at which χPT breaks down for these two observables. Using a pointwise Bayesian analysis, we find that the inferred breakdown scales are notably different for the two observables. For the chiral expansion of g_A, we obtain 251⁺²⁰₋₅₀ MeV and 211⁺²⁰₋₃₀ MeV using two distinct sets of low-energy constants, while for the chiral expansion of m_N we infer a significantly …

Radiation Protection Factor Research: The Keystone For Conventional-Nuclear Integration (Cni), Andrew W. Decker

Faculty Publications

This article briefly describes Defense Threat Reduction Agency (DTRA) vehicle Radiation Protection Factor (RPF) research and explains its critical role in enabling future Operations in a Nuclear Environment (ONE) and Conventional-Nuclear Integration (CNI) on behalf of the US Department of War (DoW).1 As such, the background and practical utility of RPF values is discussed, as well as the justification for renewed Army and DoW investment into RPF research to enhance Joint military planning, survivability, and lethality on tomorrow’s nuclear battlefields. Advances in DTRA RPF research directly strengthen US strategic and extended deterrence efforts and support all Agencies and Departments responsible …

Factors Associated With Lapses In Care Among People Living With Hiv In South Carolina, Xueying Yang Ph.D., Fanghui Shi, Shujie Chen, Gavi Samuel, Bankole Olatosi Ph.D., Sharon Weissman, Xiaoming Li Ph.D., Jiajia Zhang Ph.D.

Faculty Publications

Utilizing statewide electronic health records (EHR) data, this study aims to assess the factors determining the occurrence of lapses in HIV care among people with HIV (PWH) in South Carolina (SC). All adult (≥ 18 years old) PWH who were diagnosed with HIV between 2006 and 2018 with at least two HIV care encounters and at least 1-year follow-up record were included in the analysis. The outcome, a lapse in care, was defined as a repeated measure of HIV care encounter that occurs over a year following the previous visit. Generalized Estimation Equation models were employed. The study cohort had …

Implementation And Costs Of A Food Insecurity Resource Navigation Program For Primary Care Patients With Diabetes And Hypertension In South Carolina, Deeksha Gupta, Darin Thomas, Stella Coker Watson Self Ph.D., Ms, Edward A. Frongillo Jr. Ph.D., Alain H. Litwin, Joseph A. Ewing, Lynnette Ramos-Gonzalez, Lynnette Ramos-Gonzalez

Faculty Publications

Objective

To examine food insecurity resource navigation program costs and how navigation intensity relates to clinical outcomes, healthcare costs, and quality of life (QOL) for diabetes and/or hypertension patients.

Methods

This retrospective study included patients receiving resource navigation (July 12, 2021-December 31, 2022 with twelve-month follow-up) across three primary care practices in South Carolina's largest health system. Participants were 18+ years old (from electronic medical records/Epic), had food insecurity (from Hunger Vital Sign™), and diabetes and/or hypertension (from Epic registries). Matched controls came from food insecurity screening-only practices. Patients in each group (n= 219) had diabetes (9.13%), hypertension …

Multiscale Computational Modeling Of The Cardiopulmonary Consequences Of Postnatal Hyperoxia With Implications For Preterm-Born Children, Salla M. Kim, Filip Jezek, Pim J. A. Oomen, Gregory P. Barton, Feng Gu, Daniel A. Beard, Kara N. Goss, Mitchel J. Colebank, Naomi C. Chesler

Faculty Publications

Moderate to extreme preterm birth (<  32 weeks gestation) affects cardiopulmonary structure and function and is associated with increased risk of heart failure through adulthood. The rat hyperoxia (Hx) model (term born; postnatal Hx exposure) captures biventricular changes, including at the cell and organ scale, and pulmonary vascular remodeling seen in preterm humans. However, synthesizing these measures across scales and organ systems is challenging. We hypothesized that in silico modeling of biventricular mitochondrial, myofiber, and organ-scale function plus circulatory function could capture key features of cardiopulmonary abnormalities due to preterm birth. Therefore, we calibrated a multiscale model to subject-specific biventricular pressure–volume data previously obtained from Hx rats alongside normoxic (Nx) controls to investigate the abnormalities in cardiopulmonary function at multiple scales in this animal model of human preterm birth. The calibrated model demonstrates excellent agreement with the data and captures the expected pulmonary vascular changes and right ventricular dilation seen in preterm-born children. Our multiscale modeling approach captures cardiopulmonary abnormalities across spatial scales and provides an innovative approach to explore the consequences of preterm birth beyond preclinical experimental data alone. This is a foundational step in understanding the impact of preterm birth on cardiopulmonary disease in childhood as well as adulthood.

Optimal Error Estimates Of The Diffuse Domain Method For Second Order Parabolic Equations, Wenrui Hao, Lili Ju, Yuejin Xu

Faculty Publications

In this paper, we study the convergence behavior of the diffuse domain method (DDM) for solving a class of second-order parabolic partial differential equations with Neumann boundary condition posed on general irregular domains. The DDM employs a phase-field function to extend the original parabolic problem to a similar but slightly modified problem defined over a larger rectangular domain that contains the target physical domain. Based on the weighted Sobolev spaces, we rigorously establish the convergence of the diffuse domain solution to the original solution as the interface thickness parameter goes to zero, together with the corresponding optimal error estimates under …

The Blurred Boundaries Of Care: A Qualitative Analysis Of Nurse-Doula Role Conflict, Curisa Mae Tucker Phd, Rn, Maria Mcclam, Kelly Russin Dnp, Rnc-Ob, Chse, Nansi Boghossian, Rachel Gulczinski, Lauren Workman

Faculty Publications

Introduction:

Methods:

Association Between The Dietary Index For Gut Microbiota (Di-Gm) And Colorectal Cancer In The Plco Cohort, Bezawit E. Kase, Angela D. Liese Ph.D., Jiajia Zhang Ph.D., Elizabeth Angela Murphy, Susan E. Steck Phd, Mph, Rd

Faculty Publications

Objectives: The study aimed to examine the association between a dietary index for gut microbiota (DI-GM) and the risk of incident colorectal cancer (CRC). Clarifying the role of diet-induced alterations in the composition and function of gut microbiota on the development of CRC can contribute to prevention efforts. Methods: Participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening trial enrolled in the intervention arm and who completed baseline assessments were included in the analysis (n = 55,685). The DI-GM is a literature-derived index used to score diet quality in terms of maintaining healthy gut microbiota. A time-dependent Cox model …

Association Between The Dietary Index For Gut Microbiota (Di-Gm) And Colorectal Cancer In The Plco Cohort, Bezawit E. Kase, Angela D. Liese, Jiajia Zhang, Elizabeth Angela Murphy, Susan E. Steck

Faculty Publications

Objectives: The study aimed to examine the association between a dietary index for gut microbiota (DI-GM) and the risk of incident colorectal cancer (CRC). Clarifying the role of diet-induced alterations in the composition and function of gut microbiota on the development of CRC can contribute to prevention efforts. Methods: Participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening trial enrolled in the intervention arm and who completed baseline assessments were included in the analysis (n = 55,685). The DI-GM is a literature-derived index used to score diet quality in terms of maintaining healthy gut microbiota. A time-dependent Cox model …

Role Of Wadsley Defects And Cation Disorder To Enhance Monb12O33 Diffusion, Cj Sturgill, Manish Kumar, Nima Karimitari, Iva Millisavljevic, Coby S. Collins, Aaron Hegler, Hsin-Yun Joy Chao, Santosh Kiran Balijepalli, Scott T. Misture, Christopher Sutton, Morgan Stefik

Faculty Publications

Wadsley-Roth (WR) niobates have emerged as high-rate anode materials that can combine rapid ionic diffusion with good electronic conductivity. WR compounds have been defect-enhanced by limited annealing, however, such materials often contain multiple types of defects. In particular, both Wadsley defects (variable block size) and transition metal disorder have the potential to modify transport rates, however the corresponding effects are not well understood mechanistically. Here, MoNb12O33 (MNO) was calcined at two different temperatures to compare a defect-rich condition (MNO-800) with a proximal order-rich condition (MNO-900) as assessed through XRD, XANES, EXAFS, and STEM characterizations. Galvanostatically cycled lithium half cells of …

First-Order Axial Perturbation Of The Reissner–Nordström Metric Against A Possible Parity-Violating Gravity Background, Abhishek Rout, Brett David Altschul

Faculty Publications

We study axial perturbations of Reissner–Nordström black holes within the general frame-work of parity-violating modified gravity theories. We derive the governing equations for a class of frame-dragging perturbations, focusing on the symmetry structure and radial dependence of the perturbed metric component, describing its behavior across three distinct regions: near the singularity (r → 0), between the inner and outer Reissner–Nordström horizons (r− < r < r+), and in the asymptotic exterior regime (r → ∞). Using a combination of analytical and numerical methods, we analyze the solutions for varying black hole charge-to-mass ratios (Q/M) and angular momentum parameters (l). Key findings include the suppression of perturbations by the electromagnetic field for higher Q/M; the emergence of radial resonance-like behavior for specific l values; and a high degree of symmetry for solutions in the extremal limit (Q/M ∼ 1), attributed to the AdS2 × S 2 near-horizon geometry. The WKB approximation is employed to study the high-l regime, revealing quantized radial resonance modes and singular behavior in the extremal limit. Additionally, we explore the role of boundary conditions and the possibility of a Chern–Simons field Θ as the source of the parity violation, showing that consistency and the behavior of the perturbations under time reversal demand a constant field (and thus no actually observable Chern–Simons effects) at leading order. These results provide a basis for further analysis of the stability and dynamical properties of charged black holes in parity-violating theories, with potential experimental signatures in gravitational wave observations.

Dietary Inflammatory Index And Objective Disease Activity In Ibd: No Association Found, Rúbia Moresi Vianna De Oliveira, Ana Carolina Junqueira Vasques, Stefhani Andrioli Romero, Nitin Shivappa Mbbs, Mph, Ph.D., Michael David Wirth, James Hébert Scd, Glaucia Fernanda Soares Ruppert Reis, Cristiane Kibune Nagasako

Faculty Publications

Background

Inflammatory Bowel Disease (IBD) involves genetic and environmental factors, but the relationship between disease activity, adiposity, and diet remains unclear.

Objective

To investigate the association between endoscopic/radiological activity of IBD, body adiposity, and the Dietary Inflammatory Index with or without adjustment for energy density (E-DII or DII).

Method

An observational, cross-sectional study was carried out. Endoscopic activity was defined by an endoscopic Mayo score >2, Crohn’s Disease Endoscopic Index of Severity (CDEIS) > 5, and/or the presence of a deep ulcer in any intestinal segment. Body adiposity was estimated using the body mass index, waist circumference, and waist-hip ratio (WHR). …

Circulating Levels Of Insulin-Like Growth Factor I (Igf-I) And Risk Of Multiple Myeloma: An Observational And Mendelian Randomisation Study, Yolanda Benavente, Sara Hermosa, Nikos Papadimitriou, Alyssa I. Clay-Gilmour Ph.D., Elizabeth E. Brown, Jonathan N. Hofmann, Nathaniel Rothman, Qin Lan, Sonja I. Berndt, Demetrius Albanes, Mark Purdue, Mitchell J. Machiela, Stephen J. Chanock, Parveen Bhatti, Wendy Cozen, Aaron Norman, Susan L. Slager, James R. Cerhan, Vincent Rajkumar, Et. Al.

Faculty Publications

No abstract provided.

Analogy2kg: An Automatic Pipeline For Deriving Knowledge Graphs From Long-Text Analogies, Kara Combs, Lance E. Champagne, Bruce A. Cox, Christine M. Schubert Kabban, Trevor Bihl, Grace Lemming

Faculty Publications

Analogical reasoning is an increasingly popular, lightweight solution to enable large language model (LLM)-level reasoning without computational complexity. Still, it has yet to be adopted due to its reliance on strictly hand-formatted data. Therefore, we propose Analogy2KG (“Analogy to Knowledge Graph”), as an automatic pipeline that transforms text into a KG format via a fine-tuned version of information extraction (IE) algorithms for long-text analogies. The need to verify that the complex underlying analogical structure of the data is maintained was done via paired samples tests in the creation and validation of this pipeline. Graph density was used to evaluate the …

New Avenues For |Δb=2| Processes Beyond Neutron-Antineutron Oscillations, Arnau Basi Beneito, Svjetlana Fajfer, Alexey A. Petrov

Faculty Publications

We explore baryon-number-violating (|∆B| = 2) processes beyond the well-known neutron-antineutron (n-n̄) oscillations, focusing on the Λ-Λ̄ system. The presence of a strange quark in the Λ baryon introduces a new set of six-quark operators roughly of the form (uds)², which are different from the (udd)² operators responsible for n-n̄ oscillations. Using the Standard Model Effective Field Theory (SMEFT), we classify all dimension-9 operators that cause |∆B| = 2  transitions and study their UV completions mediated by exotic scalar fields with trilinear interactions. We demonstrate that …

Efficient Energy-Stable Discontinuous Galerkin Schemefor The Non-Isothermal Cahn–Hilliard–Navier–Stokestwo-Phase Fluid Flow System, Guang-An Zou, Meiting Wang, Kejia Pan, Yin Yang, Xiaofeng Yang

Faculty Publications

In this article, we propose a novel numerical framework for the non-isothermal Cahn–Hilliard–Navier–Stokes two-phase flow system, which couples the incompressible Navier–Stokes equations, the Cahn–Hilliard phase-field equation, and the heat transport equation to capture temperature-dependent two-phase flow dynamics. The pro-posed scheme achieves three major advances: (i) unconditional energy stability through a combined scalar auxiliary variable (SAV) and zero-energy-contribution (ZEC) approach, (ii) linearity and full decoupling of all variables while using a second-order temporal discretization, and (iii) efficient implementation via discontinuous Galerkin (DG) spa-tial discretization together with a second-order projection method for the Navier–Stokes equations. We rigorously prove the unconditional energy stability …

Congruence Properties Modulo Prime Powers For A Class Of Partition Functions, Matthew Boylan, Swati .

Faculty Publications

Let p be prime, and let p_[1,p](n) denote the function whose generating function is

∏ _n≥1 (1 − qⁿ)⁻¹ (1 − q^pn)⁻¹.

This function and its generalizations p_[c^r,d^m](n) are the subject of study in several recent papers. Let ℓ ≥ 5, let j ≥ 1, and let p ∈ {2, 3, 5}. In this paper, we prove that the generating function for p_[1,p](n) in the progression β_{p,ℓ,j …}

Ulk4 And Cdkn2a Polymorphisms Influence The Risk Of Developing Monoclonal Gammopathy Of Undetermined Significance, José Manuuel Sánchez-Maldonado, Angelica Macauda, Antonio José Cabrera-Serrano, Hauke Thomsen, Murat Güler, Rob Ter Horst, Bethany Van Guelpen, Pavel Vodicka, Stefano Landi, Subhayan Chattopadhyay, Pelin Ünal, Lucía Ruiz-Durán, Delphine Casabonne, Hartmut Goldschmidt, Istemi Serin, María Carretero-Fernández, Elena Cabezudo, Fernando Reyes-Zurita, Alyssa I. Clay-Gilmour, Et. Al.

Faculty Publications

Monoclonal gammopathy of undetermined significance (MGUS) is a necessary precursor condition to multiple myeloma (MM). Given the role of autophagy in modulating MM risk, we investigated whether genetic variation in autophagy-related genes influences susceptibility to MGUS. We analyzed the association of 34,042 common autophagy-related single nucleotide polymorphisms (SNPs) with MGUS across six independent cohorts, five from Europe and one from North America, comprising 2317 MGUS cases and 282,358 controls. We also assessed their impact on immune parameters, including absolute counts of 91 blood-derived immune cell subsets and 103 circulating immunological proteins. Meta-analysis revealed a genome-wide significant association between the ULK4 …

Impact Of Medicaid Enrollment Timing On Tumor Stage At Diagnosis And Survival In Breast, Colorectal, And Lung Cancer, Gabriel A. Benavidez, Stella Coker Watson Self Ph.D., Ms, Anthony Alberg Ph.D., M.P.H., Janice Probst, Jan Marie Eberth

Faculty Publications

Background: Medicaid-insured patients experience higher rates of late-stage cancer diagnosis and worse survival than non-Medicaid patients. The impact of Medicaid enrollment timing on cancer outcomes is less clear. This study examines the association between Medicaid enrollment and timing with tumor stage and cancer-specific survival for breast, colorectal, and lung cancers. Methods: We analyzed SEER-Medicaid linked data for 276,755 breast, 104,784 colorectal, and 101,058 lung cancer patients < 65 years of age. Patients were categorized as non-Medicaid enrollees, pre-diagnosis enrollees (≥12 months before), or post-diagnosis enrollees (≤12 months after). Multivariable logistic regression estimated odds ratios of late-stage diagnosis, and cause-specific Cox proportional hazards models were used to assess cancer-specific survival, adjusting for demographic and socioeconomic factors. Results: Compared to non-Medicaid enrollees, post-diagnosis enrollees had the highest odds of late-stage diagnosis (breast cancer: OR: 3.41; colorectal cancer: OR: 3.78; lung cancer: OR: 1.87). Pre-diagnosis enrollees also had increased odds, but the …

Rural–Urban Differences In Cognitive Outcomes Among Older Adults: The Roles Of Falls And Depressive Symptoms, Ayse Malatyali, Tom Cidav, Lisa A.K. Wiese, Jian Zou, Monique J. Brown Ph.D., Mph, Junfeng Ma, Breno S. Diniz, Ladda Thiamwong

Faculty Publications

Background: Older adults with Alzheimer’s Disease and Related Dementias (ADRD) experience a higher risk of falls. However, research lacks evidence on the effect of fall exposure on cognitive impairment and dementia. We investigated the association of falls and depressive symptoms with cognitive impairment and dementia in a nationally representative sample. Methods: We analyzed data from 6221 participants (age ≥ 65) in the Health and Retirement Study (HRS) from the 2018–2020 waves, using Multinomial logistic regression models. Measures included the HRS health status questionnaire, HRS cognition scale, and the Center for Epidemiological Studies Depression scale. Results: Prevalence of fall exposure across …

Rural–Urban Differences In Cognitive Outcomes Among Older Adults: The Roles Of Falls And Depressive Symptoms, Ayse Malatyali, Tom Cidav, Lisa A.K. Wiese, Jian Zou, Monique J. Brown Ph.D., Mph, Junfeng Ma, Breno S. Diniz, Ladda Thiamwong

Faculty Publications

Background: Older adults with Alzheimer’s Disease and Related Dementias (ADRD) experience a higher risk of falls. However, research lacks evidence on the effect of fall exposure on cognitive impairment and dementia. We investigated the association of falls and depressive symptoms with cognitive impairment and dementia in a nationally representative sample. Methods: We analyzed data from 6221 participants (age ≥ 65) in the Health and Retirement Study (HRS) from the 2018–2020 waves, using Multinomial logistic regression models. Measures included the HRS health status questionnaire, HRS cognition scale, and the Center for Epidemiological Studies Depression scale. Results: Prevalence of fall exposure across …

Characterizing Atmospheric Turbulence With The Lunar Step Response Method, Patrick D. Carattini, Caleb J. Stilp, Katelyn M. Atkinson, Stephen C. Cain

Faculty Publications

Most methods that astronomers use to characterize the strength of atmospheric turbulence in and around their observatories use differential image motion monitors observing a star to provide the necessary data for the measurement. With the Moon becoming a greater national priority, the need to characterize atmospheric paths between observatories on Earth and the Moon is potentially going to grow in the future. To this end, the differential image motion monitor is not an ideal instrument for characterizing turbulence along paths between observatories and the Moon as the bright Moon makes it difficult to detect and locate stars in its vicinity. …

Main-Chain Ion-Pair Polybenzimidazole Membranes Enabling Reduced-Temperature Ht-Pemfc Operation (Down To 120°C), Huina Lin, Brian C. Benicewicz

Faculty Publications

Proton exchange membrane (PEM) fuel cells are promising for clean and efficient energy conversion across diverse applications. High-temperature PEM fuel cells (HT-PEMFCs) using phosphoric acid (PA)-doped polybenzimidazole (PBI) can operate up to 200°C, but at lower temperatures, water-induced PA loss often leads to performance degradation and reduced durability. In this work, we present a new class of main-chain ion-pair PBI membranes by integrating the imidazolium-biphosphate ion-pair units directly into the PBI backbone. This design results in membranes with high acid content, stronger acid-polymer interactions and stabilized acid retention. In single-cell tests, the Im⁺-PBI15-3 wt.% exhibits peak power densities …

Generation Of Inner Core Anisotropy By Anisotropic Thermal Conductivity Of Iron Crystals, Prajna Paramita Das, Bruce Buffett, Daniel A. Frost

Faculty Publications

Seismic anisotropy in the Earth’s inner core refers to the observation that seismic waves travel faster along the Earth’s rotation axis than in the equatorial plane, a feature inferred from decades of global seismological observations. This directional dependence of wave speeds provides important clues about the structure, composition and dynamics of the inner core. Here we explore a coupled thermo-mechanical mechanism for the generation of inner core anisotropy, focusing on the effects of anisotropic thermal conductivity in iron crystals as the inner core cools. We propose that the higher thermal conductivity of iron along the crystallographic c-axis compared with …