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Physical Sciences and Mathematics Commons

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Articles 1 - 12 of 12

Full-Text Articles in Physical Sciences and Mathematics

Exploring Dft+U Parameter Space With A Bayesian Calibration Assisted By Markov Chain Monte Carlo Sampling, Pedram Tavadze, Reese Boucher, Guillermo Avendaño-Franco, Keenan X. Kocan, Sobhit Singh, Viviana Dovale-Farelo, Wilfredo Ibarra-Hernández, Matthew B. Johnson, David S. Mebane, Aldo H. Romero Nov 2021

Exploring Dft+U Parameter Space With A Bayesian Calibration Assisted By Markov Chain Monte Carlo Sampling, Pedram Tavadze, Reese Boucher, Guillermo Avendaño-Franco, Keenan X. Kocan, Sobhit Singh, Viviana Dovale-Farelo, Wilfredo Ibarra-Hernández, Matthew B. Johnson, David S. Mebane, Aldo H. Romero

Faculty & Staff Scholarship

The density-functional theory is widely used to predict the physical properties of materials. However, it usually fails for strongly correlated materials. A popular solution is to use the Hubbard correction to treat strongly correlated electronic states. Unfortunately, the values of the Hubbard U and J parameters are initially unknown, and they can vary from one material to another. In this semi-empirical study, we explore the U and J parameter space of a group of iron-based compounds to simultaneously improve the prediction of physical properties (volume, magnetic moment, and bandgap). We used a Bayesian calibration assisted by Markov chain Monte Carlo …


On The Use Of Minimum Penalties In Statistical Learning, Ben Sherwood, Bradley S. Price Jul 2021

On The Use Of Minimum Penalties In Statistical Learning, Ben Sherwood, Bradley S. Price

Faculty & Staff Scholarship

Modern multivariate machine learning and statistical methodologies estimate parameters of interest while leveraging prior knowledge of the association between outcome variables. The methods that do allow for estimation of relationships do so typically through an error covariance matrix in multivariate regression which does not scale to other types of models. In this article we proposed the MinPEN framework to simultaneously estimate regression coefficients associated with the multivariate regression model and the relationships between outcome variables using mild assumptions. The MinPen framework utilizes a novel penalty based on the minimum function to exploit detected relationships between responses. An iterative algorithm that …


Do Mitigated Wetlands Support Similar Small Mammal Communities As Natural Wetlands?, Krista Noe, Mack Frantz, Christopher T. Rota, Jim Anderson May 2021

Do Mitigated Wetlands Support Similar Small Mammal Communities As Natural Wetlands?, Krista Noe, Mack Frantz, Christopher T. Rota, Jim Anderson

Presentations

Wetlands provide many ecosystem services and play an important ecological role in wildlife communities. Although wetland mitigation is a standard tool to combat losses to natural wetlands, it is essential to understand if mitigated wetlands are truly replacing natural wetlands in their full capacity. Because one important role of wetlands is to provide habitat for wildlife communities, it is important to determine if these created or restored wetlands can foster a wildlife community that is similar to natural wetlands. One understudied taxa in the realm of wetland mitigation research is small mammals. Our objectives are to examine community composition, occupancy, …


Relating Recharge Mechanisms To Dissolved Inorganic Carbon Dynamics In An Updip Appalachian Coal Mine Discharge, Matthew L. Bell May 2021

Relating Recharge Mechanisms To Dissolved Inorganic Carbon Dynamics In An Updip Appalachian Coal Mine Discharge, Matthew L. Bell

Presentations

Impaired drainage from active and abandoned mines degrades the water quality of receiving streams and aquifers. Coal mine drainage (CMD) has been studied for decades in Appalachia, but unknowns and uncertainties are still present, including the influence of mine hydrogeology on the outflow chemistry of above-drainage mines. To evaluate the influence of recharge type on above-drainage mine dissolved inorganic carbon chemistry, samples were collected every two weeks at a CMD outflow treatment system in Harrison County, West Virginia. Samples were collected to measure geochemical changes taking place in the mine workings and along the flowpath of the passive treatment system. …


Comparison Of Methods For Estimating Carbon Evasion And Export Associated With A Coal Mine Discharge, Kyle Lee, Dorothy J. Vesper May 2021

Comparison Of Methods For Estimating Carbon Evasion And Export Associated With A Coal Mine Discharge, Kyle Lee, Dorothy J. Vesper

Presentations

The evasion of CO2 from terrestrial waters plays a role in the global cycling of carbon but there are few datasets that have an accurate accounting of the flux. It has been shown that discharges from coal mines can have elevated concentrations of CO2 due to sulfuric acid-driven dissolution of carbonate rock. In this study, we compared three methods for calculating the export dissolved inorganic carbon (DIC) and the evaluation of CO2 from an abandoned-mine discharge in West Virginia. In Method #1, the source flux is calculated from the discharge and the concentrations at the portal. In Method #2, the …


Quantifying The Contribution Of Solid Precipitates To The Total Alkalinity In A Coal-Mine Discharge, Lili Lei, Dorothy Vesper May 2021

Quantifying The Contribution Of Solid Precipitates To The Total Alkalinity In A Coal-Mine Discharge, Lili Lei, Dorothy Vesper

Presentations

Flocculates and precipitates from coal mine drainage (CMD) are an integral part of the geochemical setting in mining-impacted streams. The precipitates may be very small, amorphous, and, depending on their chemistry, play a role in the storage and release of alkalinity. To evaluate the potential impact of CMD-solids on alkalinity, we conducted various tests using model and natural solids. Laboratory measurements of alkalinity are operationally defined by a titration to a fixed pH. When the solid-solution mixtures were tested using the standard alkalinity measurement method, no alkalinity could be detected; however, a possible reason for that was that the standard …


Development Of A Python Library To Facilitate Wqx Dataset Exchanges, Jonathan Musselwhite, Fernando Rojano May 2021

Development Of A Python Library To Facilitate Wqx Dataset Exchanges, Jonathan Musselwhite, Fernando Rojano

Presentations

The assistance of programming tools to speed up the exchange of water quality datasets are necessary. These tools reduce and simplify the steps currently needed to transfer datasets from water quality monitoring stations to public databases. Here it is presented a library developed in Python that programmatically covers the steps related to the upload of datasets following the framework of the Water Quality Exchange (WQX) of the US EPA. This library is mainly characterized by its ability to efficiently connect and transfer data formatted as CSV or XLSX files via the WQX to the National STORET Data Warehouse by mostly …


Functionalized Polycarbonate Commercial Filters For Water Purification, Jeremy Mccloud, Ashton Caruthers, Kennedy Shoults, Rick Sharpe, Sean P. Mcbride May 2021

Functionalized Polycarbonate Commercial Filters For Water Purification, Jeremy Mccloud, Ashton Caruthers, Kennedy Shoults, Rick Sharpe, Sean P. Mcbride

Presentations

Can commerercially available filtration membranes be easily functionalized in such a way to enhence the removal the charged contaminants in the water treatment process? The literature demonstrates there have been two pioneering works that demonstrated that Ultrathin Self-Assembled Nanoparticle (USANP) membranes (composed of ~5 nm diameter metallic gold nanoparticles surrounded by organic ligands) when applied to commercial membranes displayed charge sensitive rejection to molecular dyes and also have the ability to charge modify the openings in commercial filters. The rejection mechanisms in these works are proposed to be either size dependent or charged based. Recent experimental results have demonstrated that …


Evaluating Impacts Of Anthropogenic Disturbance To Wetland Water Quality Functions, Sindupa De Silva, Jim Anderson, Jason A. Hubbart, Michael P. Strager, Elliott Kellner, Christopher T. Rota, Elizabeth A. Byers May 2021

Evaluating Impacts Of Anthropogenic Disturbance To Wetland Water Quality Functions, Sindupa De Silva, Jim Anderson, Jason A. Hubbart, Michael P. Strager, Elliott Kellner, Christopher T. Rota, Elizabeth A. Byers

Presentations

Wetland ecosystems play fundamental roles in regulating our freshwater resources, yet they are not comprehensively protected from degradation and loss. West Virginia, USA has wetlands across diverse landscapes and geography that feed into both the Chesapeake Bay and Gulf of Mexico. The state is also comprised of diverse anthropogenic land-use practices. We are assessing 200 wetlands over 2 years to evaluate how anthropogenic disturbance impact wetland water quality functions. Select water quality parameters (20), and relative diversity and abundance of vegetation and macroinvertebrates will be used as bioindicators. They will be compared with GIS assessments of watershed land cover/ land-use …


Boulders As A Lithologic Control On River And Landscape Response To Tectonic Forcing At The Mendocino Triple Junction, Charles Shobe, Georgina Bennett, Gregory Tucker, Kevin Roback, Scott Miller, Joshua Roering Mar 2021

Boulders As A Lithologic Control On River And Landscape Response To Tectonic Forcing At The Mendocino Triple Junction, Charles Shobe, Georgina Bennett, Gregory Tucker, Kevin Roback, Scott Miller, Joshua Roering

Faculty & Staff Scholarship

Constraining Earth’s sediment mass balance over geologic time requires a quantitative understanding of how landscapes respond to transient tectonic perturbations. However, the mechanisms by which bedrock lithology governs landscape response remain poorly understood. Rock type influences the size of sediment delivered to river channels, which controls how efficiently rivers respond to tectonic forcing. The Mendocino triple junction region of northern California, USA, is one landscape in which large boulders, delivered by hillslope failures to channels, may alter the pace of landscape response to a pulse of rock uplift. Boulders frequently delivered by earthflows in one lithology, the Franciscan mélange, have …


The Role Of Infrequently Mobile Boulders In Modulating Landscape Evolution And Geomorphic Hazards, Charles M. Shobe, Jens M. Turowski, Ron Nativ, Rachel C. Glade, Georgina L. Bennett, Benedetta Dini Jan 2021

The Role Of Infrequently Mobile Boulders In Modulating Landscape Evolution And Geomorphic Hazards, Charles M. Shobe, Jens M. Turowski, Ron Nativ, Rachel C. Glade, Georgina L. Bennett, Benedetta Dini

Faculty & Staff Scholarship

A landscape’s sediment grain size distribution is the product of, and an important influence on, earth surface processes and landscape evolution. Grains can be large enough that the motion of a single grain, infrequently mobile in size-selective transport systems, constitutes or triggers significant geomorphic change. We define these grains as boulders. Boulders affect landscape evolution; their dynamics and effects on landscape form have been the focus of substantial recent community effort. We review progress on five key questions related to how boulders influence the evolution of unglaciated, eroding landscapes: 1) What factors control boulder production on eroding hillslopes and the …


Supporting Student Success And Persistence In Stem With Active Learning Approaches In Emerging Scholars Classrooms, David Miller, Jessica Deshler, Tim Mceldowney, John Stewart, Edgar Fuller, Matt Pascal, Lynnette Michaluk Jan 2021

Supporting Student Success And Persistence In Stem With Active Learning Approaches In Emerging Scholars Classrooms, David Miller, Jessica Deshler, Tim Mceldowney, John Stewart, Edgar Fuller, Matt Pascal, Lynnette Michaluk

Faculty & Staff Scholarship

Over the last several decades, Emerging Scholars Programs (ESPs) have incorporated active learning strategies and challenging problems into collegiate mathematics, resulting in students, underrepresented minority (URM) students in particular, earning at least half of a letter grade higher than other students in Calculus. In 2009, West Virginia University (WVU) adapted ESP models for use in Calculus I in an effort to support the success and retention of URM STEM students by embedding group and inquiry-based learning into a designated section of Calculus I. Seats in the class were reserved for URM and first- generation students. We anticipated that supporting students …