Digital Commons Network^™

Irrigation-Intensive Groundwater Modeling Of Complex Aquifer Systems Through Integration Of Big Geological Data, Hamid Vahdat-Aboueshagh, Frank T.C. Tsai, Dependra Bhatta, Krishna P. Paudel

Faculty Publications

This study identifies hydrogeologic characteristics of complex aquifers based on constructing stratigraphic structure with large, non-uniform well log data. The approach was validated through a modeling study of the irrigation-intensive Chicot aquifer system, which is an important Pleistocene-Holocene aquifer of the Coastal Lowlands aquifer system in the southwestern Louisiana. Various well log types were unified into the same data structure, prioritized based on data sources, and interpolated to generate a detailed stratigraphic structure. More than 29,000 well logs were integrated to construct a stratigraphy model of 56 model layers for the Chicot aquifer system. The stratigraphy model revealed interconnections of …

Dietary Inflammatory Index Is Related To Heart Failure Risk And Cardiac Function: A Case-Control Study In Heart Failure Patients, Jalal Moludi, Nitin Shivappa Mbbs, Mph, Ph.D., Soghra Alisgharzadeh, James R. Hébert Scd, Mohammad Alizadeh

Faculty Publications

Aims: Previous studies suggest that diet and inflammation are important risk factors for heart failure (HF); however, the associations remain unclear. The Dietary Inflammatory Index (DII®) was established to measure the inflammatory capacity of individuals' diet. This study aimed to explore the DII in HF subjects compared with controls. Methods and Results: We conducted a case–control (116 cases and 113 controls) study that recruited in the similar clinics. DII scores were calculated based on dietary intakes. N-Terminal pro-brain natriuretic peptide (NT-proBNP) levels and ejection fraction (EF) were assessed in both groups. In order to analyze DII scores with HF as …

The Remains Of The Fray: Nascent Colonialism And Heterogeneous Hybridity, Charles R. Cobb, James B. Legg, Steven D. Smith, Chester B. Depratter, Brad R. Lieb, Edmond A. Boudreaux Iii

Faculty Publications

Investigations at the Native American site complex of Stark Farms in Mississippi, USA, have yielded numerous examples of metal artifacts of European origin. Our study suggests that they derive from contact between the AD 1540–1541 winter encampment of the Spanish Hernando de Soto expedition and the local Indigenous polity. The artifacts display a wide range of modifications, uses, and depositional contexts congruent with hybrid practices. We argue that the early colonial setting of Stark Farms requires a different perspective on cultural mixing than is often applied in studies of European colonialism. This is highlighted by the strongly improvisational nature of …

Dynamic Energy Budget Modelling To Predict Eastern Oyster Growth, Reproduction, And Mortality Under River Management And Climate Change Scenarios, Romain Lavaud, Megan K. La Peyre, Dubravko Justic, Jerome F. La Peyre

Faculty Publications

Eastern oysters growing in deltaic Louisiana estuaries in the northern Gulf of Mexico must tolerate considerable salinity variation from natural climate variability (e.g., rainfall and stream run-off pushing isohalines offshore; tropical storms pushing isohalines inshore) and man-made diversions and siphons releasing freshwater from the Mississippi River. These salinity variations are predicted to increase with future climate change because of the increased frequency of stronger storms and also in response to proposed large-scale river diversions. Increased Mississippi River flow into coastal estuaries from river diversions, along with potential changes in rainfall and stream run-off from climate change will alter spatial and …

Extensive Decentralized Hydrogen Export From The Atlantis Massif, Susan Q. Lang, Marvin D. Lilley, Tamara Baumberger, Gretchen L. Früh-Green, Sharon L. Walker, William J. Brazelton, Debroah S. Kelley, Mitchell Elend, David A. Butterfield, Aaron J. Mau

Faculty Publications

Hydrogen is an important energy source for subsurface microbial communities, but its availability beyond the flow focused through hydrothermal chimneys is largely unknown. We report the widespread export of H₂ across the Atlantis Massif oceanic core complex (30°N, Mid-Atlantic Ridge; up to 44 nM), which is distinct from the circulation system feeding the Lost City Hydrothermal Field (LCHF) on the massif's southern wall. Methane (CH₄) abundances are generally low to undetectable (<3 nM) in fluids that are not derived from the LCHF. Reducing fluids exit the seafloor over a wide geographical area and depth …

Synthesis And Characterization Of Zein-Based Low Density Porous Absorbent (Zelda) For Oil Spill Recovery, Nathan P. Holley, Jin Gyun Lee, Kalliat T. Valsaraj, Bhuvnesh Bharti

Faculty Publications

Removal of spilled petroleum oil from water bodies using hydrophobic porous absorbent has garnered considerable attention due to the simplicity, large-scale adaptability and robustness of the process. However, the use of nonbiodegradable synthetic oil absorbent during cleanup has raised a secondary concern such as generating plastic pollutants that can accumulate in marine and other ecosystems. To encounter this potential hazard, there is a need to find new biocompatible alternatives to currently used non-degradable porous materials. Here we present ZEin-based Low Density porous Absorbent (ZELDA) synthesized from an emulsion templating method as a new class of naturally derived porous material with …

Timing Of Term Elective Cesarean Section And Adverse Neonatal Outcomes: A Multi-Center Retrospective Cohort Study, Ayah Al Bizri, Nansi Boghossian, Anwar Nassar, Pascale Nakad, Dina Jaber, Rabih Chahine, Gaby Fallakha, Gjaotj Makhoul, Khalid Yunis

Faculty Publications

Background Rate of cesarean section (CS), including elective CS has globally increased. Studies have found that term elective CS before 39 weeks of gestation is associated with increased risk of adverse respiratory outcomes.

Objective To determine the rate of elective CS and examine the association between timing of elective term CS and adverse neonatal outcomes in a large population of Lebanese women.

Methods A Multi-Center Study was conducted using data from the National Collaborative Perinatal Neonatal Network database. Simple and multivariable logistic regression models were used to examine the association between timing of term elective CS and adverse neonatal outcomes. …

Swipe No More?, Paul A. Djupe

Faculty Publications

No abstract provided.

Maternal Pragmatic Language Difficulties In The Fmr1 Premutation And The Broad Autism Phenotype: Associations With Individual And Family Outcomes, Jessica Klusek, Angela John Thurman, Leonard Abbeduto

Faculty Publications

Broader phenotypes associated with genetic liability, including mild difficulties with pragmatic language skills, have been documented in mothers of children with autism spectrum disorder (ASD) and mothers of children with fragile X syndrome (FXS). This study investigated the relationship between pragmatic difficulties and indicators of maternal well-being and family functioning. Pragmatic difficulty was associated with loneliness in mothers of children with ASD or FXS, and with depression, decreased life satisfaction, and poorer family relationship quality but only in mothers of children with FXS. Results suggest that subtle maternal pragmatic language difficulties are a risk factor that that may contribute to …

Tuned Mass Damper Design For Slender Masonry Structures: A Framework For Linear And Nonlinear Analysis, Marco Zucca, Nicola Longarini, Marco Simoncelli, Aly Mousaad Aly

Faculty Publications

The paper presents a proposed framework to optimize the tuned mass damper (TMD) design, useful for seismic improvement of slender masonry structures. A historical masonry chimney located in northern Italy was considered to illustrate the proposed TMD design procedure and to evaluate the seismic performance of the system. The optimization process was subdivided into two fundamental phases. In the first phase, the main TMD parameters were defined starting from the dynamic behavior of the chimney by finite element modeling (FEM). A series of linear time-history analyses were carried out to point out the structural improvements in terms of top displacement, …

A Hybrid Hidden Markov Model For Pipeline Leakage Detection, Mingchi Zhang, Xuemin Chen, Wei Li

Faculty Publications

In this paper, a deep neural network hidden Markov model (DNN-HMM) is proposed to detect pipeline leakage location. A long pipeline is divided into several sections and the leakage occurs in different section that is defined as different state of hidden Markov model (HMM). The hybrid HMM, i.e., DNN-HMM, consists of a deep neural network (DNN) with multiple layers to exploit the non-linear data. The DNN is initialized by using a deep belief network (DBN). The DBN is a pre-trained model built by stacking top-down restricted Boltzmann machines (RBM) that compute the emission probabilities for theHMMinstead of Gaussian mixture model …

Pharmacokinetic Model Analysis Of Supralingual, Oral And Intravenous Deliveries Of Mycophenolic Acid, Xiuqing Gao, Lei Wu, Robert Y.L. Tsai, Jing Ma, Xiaohua Liu, Diana S.L. Chow, Dong Liang, Huan Xie

Faculty Publications

Mycophenolic acid (MPA) is commonly used for organ rejection prophylaxis via oral administration in the clinic. Recent studies have shown that MPA also has anticancer activities. To explore new therapeutic options for oral precancerous/cancerous lesions, MPA was designed to release topically on the dorsal tongue surface via a mucoadhesive patch. The objective of this study was to establish the pharmacokinetic (PK) and tongue tissue distribution of mucoadhesive MPA patch formulation after supralingual administration in rats and also compare the PK differences between oral, intravenous, and supralingual administration of MPA. Blood samples were collected from Sprague Dawley rats before and after …

Monitoring Air Pollution Variability During Disasters, Earthea Nance

Faculty Publications

National environmental regulations lack short-term standards for variability in fine particulate matter (PM2.5); they depend solely on concentration-based standards. Twenty-five years of research has linked short-term PM2.5, that is, increases of at least 10 μg/m3 that can occur in-between regulatory readings, to increased mortality. Even as new technologies have emerged that could readily monitor short-term PM2.5, such as real-time monitoring and mobile monitoring, their primary application has been for research, not for air quality management. The Gulf oil spill offers a strategic setting in which regulatory monitoring, computer modeling, and stationary monitoring could be directly compared to mobile monitoring. Mobile …

Energy Cost Of Walking And Functional Aerobic Capacity During Moderate Intensity Exercise In Adults With Obstructive Sleep Apnea: A Cross-Sectional Study, Jeffrey E. Herrick Phd

Faculty Publications

Background: Autonomic dysregulation associated with obstructive sleep apnea (OSA) may limit cardiopulmonaryresponses to exercise, which, in turn, may impair functional aerobic capacity (FAC) and walking economy. Weaimed to characterize walking economy and FAC in OSA patients compared with healthy adults (non-OSA) andexamine their relationship with OSA severity (apnea-hypopnea index [AHI]).

Methods: A total of 26 adults (OSA,n= 13; non-OSA,n= 13) participated in this cross-sectional study. In this study,the participants with OSA were between the ages of 25 and 60 years, with a body mass index of 25 kg/m2to 39 kg/m2, and who had undergone a recent third-party sleep study with …

The Odious Intellectual Company Of Authority Restricting Second Amendment Rights To The “Virtuous”, Royce De R. Barondes

Faculty Publications

To the woes of the victims of American over-criminalization, we can add deprivation of the suitable tools for self-defense during national emergency and civil unrest. Federal law disarms “unlawful users” of controlled substances (including medical marijuana), and imposes a permanent firearms ban on substantially all those with prior felony convictions. A notable exception is made for white-collar criminals with felony violations of antitrust and certain business practice statutes.

The constitutionality of these restrictions typically is founded on the view that one is tainted as “non-virtuous” for any serious criminal conviction, which includes any felony conviction. Using extensive sampling, this article …

Beyond Stress Reduction: Mindfulness As A Skill For Developing Authentic Professional Identity, Richard C. Reuben

Faculty Publications

Mindfulness is often touted in the legal field for its capacity to help reduce stress and improve focus through the management of distractions. However, the potential contributions of mindfulness practice for the legal profession extend beyond stress reduction' and include great promise for helping lawyers understand who they are as members of the legal profession - that is, their professional identity. This knowledge is empowering because it allows lawyers facing ethical quandaries to make choices that better align their professional values with their personal values, rather than aligning their personal values with professional values and societal expectations of success. In …

Review Of The Guncle, Michael F. Russo

Faculty Publications

No abstract provided.

Book Review: Social Media And Democracy: The State Of The Field And Prospects For Reform, Cynthia W. Bassett

Faculty Publications

Social Media and Democracy illuminates the empirical social science research done to date to tease apart the effects social media has had on representative democracies. It is a collection of essays by academic social scientists researching the intersection of social media and democracy from a variety of angles.

Impact Of Follow Up Blood Cultures On Outcomes Of Patients With Community-Onset Gram-Negative Bloodstream Infection, Rajiv Amipara, Hana Rac Winders, Julie Ann Justo, P Brandon Bookstaver, Joseph Kohn, Majdi N. Al-Hasan

Faculty Publications

Background: The role of follow up blood cultures (FUBC) in the management of gram-negative bloodstream infection (GN-BSI) remains controversial. This retrospective cohort study examines the association between obtaining FUBC and mortality in GN-BSI.

Methods: Hospitalized adults with community-onset GN-BSI at Prisma Health-Midlands hospitals in South Carolina, USA from January 1, 2010 to June 30, 2015 were identified. Patients who died or were discharged from hospital within 72 h were excluded to minimize impact of survival and selection biases on results, respectively. Multivariate Cox proportional hazards regression was used to examine association between obtaining FUBC and 28-day all-cause mortality after adjustment …

Analysis Of Two-Color Photoelectron Spectroscopy For Attosecond Metrology At Seeded Free-Electron Lasers, P. K. Maroju, C. Grazioli, M. Di Fraia, M. Moioli, D. Ertel, H. Ahmadi, O. Plekan, P. Finetti, E. Allaria, L. Giannessi, G. De Ninno, S. Spampinati, A. A. Lutman, R. J. Squibb, R. Feifel, P. Carpeggiani, M. Reduzzi, T. Mazza, M. Meyer, S. Bengtsson, N. Ibrakovic, E. R. Simpson, J. Mauritsson, T. Csizmadia, M. Dumergue, S. Kühn, N. G. Harshitha, D. You, K. Ueda, M. Labeye, J. E. Bækhøj, K. J. Schafer, E. V. Gryzlova

Faculty Publications

The generation of attosecond pulse trains at free-electron lasers opens new opportunities in ultrafast science, as it gives access, for the first time, to reproducible, programmable, extreme ultraviolet (XUV) waveforms with high intensity. In this work, we present a detailed analysis of the theoretical model underlying the temporal characterization of the attosecond pulse trains recently generated at the free-electron laser FERMI. In particular, the validity of the approximations used for the correlated analysis of the photoelectron spectra generated in the two-color photoionization experiments are thoroughly discussed. The ranges of validity of the assumptions, in connection with the main experimental parameters, …

Measurements Of And + Charged-Current Cross-Sections Without Detected Pions Or Protons On Water And Hydrocarbon At A Mean Anti-Neutrino Energy Of 0.86 Gev, K. Abe, N. Akhlaq, R. Akutsu, A. Ali, C. Alt, C. Andreopoulos, L. Anthony, M. Antonova, S. Aoki, A. Ariga, T. Arihara, Y. Asada, Y. Ashida, E. T. Atkin, Y. Awataguchi, S. Ban, M. Barbi, G. J. Barker, G. Barr, D. Barrow, C. Barry, M. Batkiewicz-Kwasniak, A. Beloshapkin, F. Bench, V. Berardi, S. Berkman, L. Berns, S. Bhadra, S. Bienstock, A. Blanchet, A. Blondel, S. Bolognesi, T. Bonus, B. Bourguille, S. B. Boyd, D. Brailsford, A. Bravar, D. Bravo Berguño, C. Bronner, S. Bron, A. Bubak, M. Buizza Avanzini, J. Calcutt, T. Campbell, S. Cao, S. L. Cartwright, M. G. Catanesi, A. Cervera, A. Chappell, C. Checchia

Faculty Publications

We report measurements of the flux-integrated and + charged-current cross-sections on water and hydrocarbon targets using the T2K anti-neutrino beam with a mean beam energy of 0.86 GeV. The signal is defined as the (anti-)neutrino charged-current interaction with one induced and no detected charged pion or proton. These measurements are performed using a new WAGASCI module recently added to the T2K setup in combination with the INGRID Proton Module. The phase space of muons is restricted to the high-detection efficiency region, 400 and 30 , in the laboratory frame. An absence of pions and protons in the detectable phase spaces …

Calibration Of The Underground Muon Detector Of The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez-Muñiz, R. Alves Batista, G. A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, P. R. Araújo Ferreira, J. C. Arteaga Velázquez, H. Asorey, P. Assis, G. Avila, A. M. Badescu, A. Bakalova, A. Balaceanu, F. Barbato, R. J. Barreira Luz, K. H. Becker, J. A. Bellido, C. Berat, M. E. Bertaina, X. Bertou, P. L. Biermann, T. Bister, J. Biteau, J. Blazek, C. Bleve

Faculty Publications

To obtain direct measurements of the muon content of extensive air showers with energy above 101 eV, the Pierre Auger Observatory is currently being equipped with an underground muon detector (UMD), consisting of 219 10 m2-modules, each segmented into 64 scintillators coupled to silicon photomultipliers (SiPMs). Direct access to the shower muon content allows for the study of both of the composition of primary cosmic rays and of high-energy hadronic interactions in the forward direction. As the muon density can vary between tens of muons per m close to the intersection of the shower axis with the ground to much …

Mechanical Quantum Sensing In The Search For Dark Matter, D. Carney, G. Krnjaic, D. C. Moore, C. A. Regal, G. Afek, S. Bhave, B. Brubaker, T. Corbitt, J. Cripe, N. Crisosto, A. Geraci, S. Ghosh, J. G.E. Harris, A. Hook, E. W. Kolb, J. Kunjummen, R. F. Lang, T. Li, T. Lin, Z. Liu, J. Lykken, L. Magrini, J. Manley, N. Matsumoto, A. Monte, F. Monteiro, T. Purdy, C. J. Riedel, R. Singh, S. Singh, K. Sinha, J. M. Taylor, J. Qin, D. J. Wilson, Y. Zhao

Faculty Publications

Numerous astrophysical and cosmological observations are best explained by the existence of dark matter, a mass density which interacts only very weakly with visible, baryonic matter. Searching for the extremely weak signals produced by this dark matter strongly motivate the development of new, ultra-sensitive detector technologies. Paradigmatic advances in the control and readout of massive mechanical systems, in both the classical and quantum regimes, have enabled unprecedented levels of sensitivity. In this white paper, we outline recent ideas in the potential use of a range of solid-state mechanical sensing technologies to aid in the search for dark matter in a …

Prospects For Beyond The Standard Model Physics Searches At The Deep Underground Neutrino Experiment: Dune Collaboration, B. Abi, R. Acciarri, M. A. Acero, G. Adamov, D. Adams, M. Adinolfi, Z. Ahmad, J. Ahmed, T. Alion, S. Alonso Monsalve, C. Alt, J. Anderson, C. Andreopoulos, M. P. Andrews, F. Andrianala, S. Andringa, A. Ankowski, M. Antonova, S. Antusch, A. Aranda-Fernandez, A. Ariga, L. O. Arnold, M. A. Arroyave, J. Asaadi, A. Aurisano, V. Aushev, D. Autiero, F. Azfar

Faculty Publications

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model …

Engineering Pest Tolerance Through Plant-Mediated Rna Interference, Seung Ho Chung, Honglin Feng, Georg Jander

Faculty Publications

Expression of insect-targeted RNA interference (RNAi) constructs in transgenic plants is a promising approach for agricultural pest control. Compared to conventional chemical insecticides, RNAi target specificity is high and the potential for negative environmental effects is low. However, although numerous laboratory studies show insect growth inhibition by double stranded RNA or artificial microRNA, few of these constructs have been moved into commercial application as genetically engineered plants. Variation in RNA degradation, uptake, processing, and systemic transport in insects can influence interspecific and intraspecific differences in RNAi efficacy and the development of resistance to RNAi in agricultural settings. Further research is …

An Early Global Role For Axin Is Required For Correct Patterning Of The Anterior-Posterior Axis In The Sea Urchin Embryo, Hongyan Sun, Chieh Fu Jeff Peng, Lingyu Wang, Honglin Feng, Athula H. Wikramanayake

Faculty Publications

Activation of Wnt/β-catenin (cWnt) signaling at the future posterior end of early bilaterian embryos is a highly conserved mechanism for establishing the anterior-posterior (AP) axis. Moreover, inhibition of cWnt at the anterior end is required for development of anterior structures in many deuterostome taxa. This phenomenon, which occurs around the time of gastrulation, has been fairly well characterized, but the significance of intracellular inhibition of cWnt signaling in cleavage-stage deuterostome embryos for normal AP patterning is less well understood. To investigate this process in an invertebrate deuterostome, we defined Axin function in early sea urchin embryos. Axin is ubiquitously expressed …

Discovery And Fine-Mapping Of Height Loci Via High-Density Imputation Of Gwass In Individuals Of African Ancestry, Mariaelisa Graff, Anne E. Justice, Kristin L. Young, Eirini Marouli, Xinruo Zhang, Rebecca S. Fine, Elise Lim, Victoria Buchanan, Kristin Rand, Mary F. Feitosa, Mary K. Wojczynski, Lisa R. Yanek, Yaming Shao, Rebecca Rohde, Adebowale A. Adeyemo, Melinda C. Aldrich, Matthew A. Allison, Christine B. Ambrosone, Stefan Ambs, Christopher Amos, Donna K. Arnett, Larry Atwood, Elisa V. Bandera, Traci Bartz, Diane M. Becker, Sonja I. Berndt, Leslie Bernstein, Lawrence F. Bielak, William J. Blot, Erwin P. Bottinger, Donald W. Bowden, Jonathan P. Bradfield, Jennifer A. Brody

Faculty Publications

Although many loci have been associated with height in European ancestry populations, very few have been identified in African ancestry individuals. Furthermore, many of the known loci have yet to be generalized to and fine-mapped within a large-scale African ancestry sample. We performed sex-combined and sex-stratified meta-analyses in up to 52,764 individuals with height and genome-wide genotyping data from the African Ancestry Anthropometry Genetics Consortium (AAAGC). We additionally combined our African ancestry meta-analysis results with published European genome-wide association study (GWAS) data. In the African ancestry analyses, we identified three novel loci (SLC4A3, NCOA2, ECD/FAM149B1) in sex-combined results and two …

The Structural Evolution Of Pull-Apart Basins In Response To Changes In Plate Motion, Georgios Pavlos Farangitakis, Ken J.W. Mccaffrey, Ernst Willingshofer, Mark B. Allen, Lara M. Kalnins, Jeroen Van Hunen, Patricia Persaud, Dimitrios Sokoutis

Faculty Publications

Pull-apart basins are structural features linked to the interactions between strike-slip and extensional tectonics. Their morphology and structural evolution are determined by factors such as extension rate, the basin length/width ratio, and changes in extension direction. In this work, we investigate the effect of a change in the plate motion direction on a pull-apart basin's structure, using analogue modelling experiments with a two-layer ductile-brittle configuration to simulate continental crust rheology. We initially impose orthogonal extension on an interconnected rift and strike-slip system to drive pull-apart development. Subsequently, we rotate the relative motion vector, imposing transtensional deformation and continuing with this …

High-Energy Emission From A Magnetar Giant Flare In The Sculptor Galaxy, M. Ajello, W. B. Atwood, M. Axelsson, L. Baldini, G. Barbiellini, M. G. Baring, D. Bastieri, R. Bellazzini, A. Berretta, E. Bissaldi, R. D. Blandford, R. Bonino, J. Bregeon, P. Bruel, R. Buehler, E. Burns, S. Buson, R. A. Cameron, P. A. Caraveo, E. Cavazzuti, S. Chen, C. C. Cheung, G. Chiaro, S. Ciprini, D. Costantin, M. Crnogorcevic, S. Cutini, F. D’Ammando, P. De La Torre Luque, F. De Palma, S. W. Digel, N. Di Lalla, L. Di Venere

Faculty Publications

Magnetars are the most highly magnetized neutron stars in the cosmos (with magnetic field 1013–1015 G). Giant flares from magnetars are rare, short-duration (about 0.1 s) bursts of hard X-rays and soft γ rays1,2. Owing to the limited sensitivity and energy coverage of previous telescopes, no magnetar giant flare has been detected at gigaelectronvolt (GeV) energies. Here, we report the discovery of GeV emission from a magnetar giant flare on 15 April 2020 (refs. 3,4 and A. J. Castro-Tirado et al., manuscript in preparation). The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope detected GeV γ rays …

R Coronae Borealis Star Evolution: Simulating 3d Merger Events To 1d Stellar Evolution Including Large-Scale Nucleosynthesis, Bradley Munson, Emmanouil Chatzopoulos, Juhan Frank, Geoffrey Clayton, Courtney Crawford, Pavel A. Denissenkov, Falk Herwig

Faculty Publications

R Coronae Borealis (RCB) stars are rare hydrogen-deficient carbon-rich variable supergiants thought to be the result of dynamically unstable white dwarf mergers. We attempt to model RCB stars through all the relevant timescales by simulating a merger event in Octo-tiger, a 3D adaptive mesh refinement (AMR) hydrodynamics code, and mapping the post-merger object into MESA, a 1D stellar evolution code. We then post-process the nucleosynthesis on a much larger nuclear reaction network to study the enhancement of s-process elements. We present models that match observations or previous studies in most surface abundances, isotopic ratios, early evolution, and lifetimes. We also …