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Full-Text Articles in Chemistry

Organic Alkalinity Distributions, Characteristics, And Application To Carbonate System Calculations In Estuarine And Coastal Systems, Christopher W. Hunt, Joseph Salisbury, Xuewu Liu, Robert H. Byrne Dec 2024

Organic Alkalinity Distributions, Characteristics, And Application To Carbonate System Calculations In Estuarine And Coastal Systems, Christopher W. Hunt, Joseph Salisbury, Xuewu Liu, Robert H. Byrne

Faculty Publications

The capacity of aquatic systems to buffer acidification depends on the sum contributions of various chemical species to total alkalinity (TA). Major TA contributors are inorganic, with carbonate and bicarbonate considered the most important. However, growing evidence shows that many rivers, estuaries, and coastal waters contain dissolved organic molecules with charge sites that create organic alkalinity (OrgAlk). This study describes the first comparison of (1) OrgAlk distributions and (2) acid–base properties in contrasting estuary-plume systems: the Pleasant (Maine, USA) and the St. John (New Brunswick, CA). The substantial concentrations of OrgAlk in each estuary were sometimes not conservative with salinity …


Experimental Evaluation Of A Recrosslinkable Co2-Resistant Micro-Sized Preformed Particle Gel For Co2 Sweep Efficiency Improvement In Reservoirs With Super-K Channels, Adel Alotibi, Tao Song, Ali Al Brahim, Baojun Bai, Thomas P. Schuman Dec 2024

Experimental Evaluation Of A Recrosslinkable Co2-Resistant Micro-Sized Preformed Particle Gel For Co2 Sweep Efficiency Improvement In Reservoirs With Super-K Channels, Adel Alotibi, Tao Song, Ali Al Brahim, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A recross linkable CO2-resistant branched preformed particle gel (CO2-BRPPG) was developed for controlling CO2 injection conformance, particularly in reservoirs with super-permeable channels. Previous work focused on a millimeter-sized CO2-BRPPG in open fractures, but its performance in high-permeability channels with pore throat networks remained unexplored. This study used a sand pack model to evaluate a micro-sized CO2-BRPPG under varying conditions of salinity, gel concentration, and pH. at ambient conditions, the equilibrium swelling ratio (ESR) of the gel reached 76 times its original size. This ratio decreased with increasing salinity but remained stable …


Local Hydroclimate Alters Interpretation Of Speleothem Δ18o Records, E. W. Patterson, V. Skiba, A. Wolf, M. L. Griffiths, D. Mcgee, T. N. Bùi, M. X. Trần, T. H. Đinh, Q. Đỗ-Trọng, Gregory R. Goldsmith, V. Ersek, K. R. Johnson Oct 2024

Local Hydroclimate Alters Interpretation Of Speleothem Δ18o Records, E. W. Patterson, V. Skiba, A. Wolf, M. L. Griffiths, D. Mcgee, T. N. Bùi, M. X. Trần, T. H. Đinh, Q. Đỗ-Trọng, Gregory R. Goldsmith, V. Ersek, K. R. Johnson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Oxygen isotopes (δ18O) are the most commonly utilized speleothem proxy and have provided many foundational records of paleoclimate. Thus, understanding processes affecting speleothem δ18O is crucial. Yet, prior calcite precipitation (PCP), a process driven by local hydrology, is a widely ignored control of speleothem δ18O. Here we investigate the effects of PCP on a stalagmite δ18O record from central Vietnam, spanning 45 – 4 ka. We employ a geochemical model that utilizes speleothem Mg/Ca and cave monitoring data to correct the δ18O record for PCP effects. The resulting record …


Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller Sep 2024

Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller

Master's Theses

An extensive laboratory test program was conducted to analyze and compare the cation exchange processes in three different varieties of sodium bentonite (Na-B) geosynthetic clay liners (GCLs) over increased conditioning durations up to 32 days and investigate the effects of temperature, solution strength, and applied stress. The goal of this test program was to establish whether the variables of temperature, solution strength, and applied stress improved or degraded the engineering properties of GCLs in laboratory testing and municipal solid waste (MSW) landfill applications. The GCLs were conditioned in liquids of increasing ionic strength, using deionized water and 2, 50, and …


Method Development For The Quantification Of Critically Valuable Elements In Permian Basin Produced Waters, Carley Oliver Aug 2024

Method Development For The Quantification Of Critically Valuable Elements In Permian Basin Produced Waters, Carley Oliver

Open Access Theses & Dissertations

Produced waters (PW) are a major byproduct of the oil and gas industrial hydraulic fracturing processes that create a major waste disposal issue with a need for disposal, treatment, and reuse method developments. The current primary disposal method is subsurface injection, which can lead to high pressures in the subsurface. PWs are often highly saline from mineral leaching due to long residence in subsurface reservoirs. According to the USGS National Minerals Information Center, bromine, calcium chloride, iodine, lithium, magnesium, and sodium chloride have been found in and extracted from these domestic subsurface brines, suggesting that there may be other economically …


Chemical And Morphological Characterization Of Airborne Particulate Matter At The Jackpile-Paguate Mine, Pueblo Of Laguna, New Mexico: Implications For Potential Metals Exposure, Andreanna C. Roros Jul 2024

Chemical And Morphological Characterization Of Airborne Particulate Matter At The Jackpile-Paguate Mine, Pueblo Of Laguna, New Mexico: Implications For Potential Metals Exposure, Andreanna C. Roros

Earth and Planetary Sciences ETDs

The inhalation of windblown particulate matter (PM) derived from abandoned uranium mines (AUMs) is a potential environmental health risk to Native American communities that live in proximity to these sites. However, the aeolian transport of metal-bearing PM from AUMs, as a potential exposure pathway, has not been investigated in any detail. In this study, we sampled airborne particulate matter within the Jackpile Mine located on the lands of the Pueblo of Laguna, New Mexico using passive sampling methods to understand the characteristics of dust within the mine site. The objective was to determine the elemental concentrations, mineralogy, and morphology of …


A Speleogenetic History Of Novoafonskaya Cave In The Western Caucasus, Olga Chervyatsova, Sergey Potapov, Jonathan Baker, Dmitry Gavryushkin, Victor Polyak, Matt Heizler, Sergey Tokarev, Sergey Sadykov, Roman Dbar, Yuri Dublyansky Jun 2024

A Speleogenetic History Of Novoafonskaya Cave In The Western Caucasus, Olga Chervyatsova, Sergey Potapov, Jonathan Baker, Dmitry Gavryushkin, Victor Polyak, Matt Heizler, Sergey Tokarev, Sergey Sadykov, Roman Dbar, Yuri Dublyansky

International Journal of Speleology

Speleogenesis in hypogene karst settings may be closely tied to regional tectonic dynamics and concomitant hydrochemical evolution of karst waters. However, placing temporal constraints on these processes can require a wider array of field observations and techniques than for typical karst systems. Herein, we present a comprehensive study of Novoafonskaya Cave (Western Caucasus, Abkhazia). The updated speleogenetic history of the cave comprises four stages: (1) the most ancient, a low-T hydrothermal (ca. 40–50°C) priming stage; (2) the main stage enabled by mixing of upwelling thermomineral and locally recharged common karst waters; (3) the late sulfuric-acid speleogenesis (SAS) stage, which left …


College Of Natural Sciences Newsletter, Spring 2024, College Of Natural Sciences May 2024

College Of Natural Sciences Newsletter, Spring 2024, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 1 Dean's Message
Page 2 New Faculty and New Club on Campus
Page 3 2024 URSCAD Awards
Page 4 Day of Scholars 2024
Page 5 SDSU's First Representation at the Association for Anatomy's 2024
Annual Conference
Page 6-7 2024 Honor's College Convocation
Page 8 Other Student Activities
Page 9 Faculty Awards
Page 10-11 Other News
Page 12 2024 Drone Day and American Association of Geographers Convention - Hawaii
Page 13 55th Annual Geography Convention
Page 14 2024 Stethoscope Ceremony
Page 15 Open PRAIRIE Data



Investigation Of Temporal Variation In Sediment Deposition Within The Tropical Wouri Estuary Cameroon Using Fourier Transform Infrared Spectroscopy, Olumide Ajulo, Dr. Henry Agbogun, Dr. Hendratta Ali Apr 2024

Investigation Of Temporal Variation In Sediment Deposition Within The Tropical Wouri Estuary Cameroon Using Fourier Transform Infrared Spectroscopy, Olumide Ajulo, Dr. Henry Agbogun, Dr. Hendratta Ali

SACAD: Scholarly Activities

In this study, Fourier Transform Infrared Spectroscopy (FTIR) was employed to qualitatively analyze organic and mineral components of the sediment core collected from the Wouri Estuary. The FTIR spectra revealed distinct transmittance corresponding to different organic and mineral phases, allowing for the characterization of sediment composition. The FTIR spectra showed changes and variation progressively from the bottom to the top. These sediments are proxies for time this can be inferred to say deposition in the Wouri Estuary has always changed.


Applied Depositional Geosystems Of The Coos Bay Basin, Oregon: Organic Geochemistry, Maturation, Paleoenvironmental Reconstruction And Biostratigraphy Of The Coaledo Delta During The Middle Eocene Climatic Optimum (Meco), Allison K. Barbato Apr 2024

Applied Depositional Geosystems Of The Coos Bay Basin, Oregon: Organic Geochemistry, Maturation, Paleoenvironmental Reconstruction And Biostratigraphy Of The Coaledo Delta During The Middle Eocene Climatic Optimum (Meco), Allison K. Barbato

LSU Doctoral Dissertations

The Coos Bay Basin on the southwestern coast of Oregon is a forearc basin that contains exceptionally preserved Eocene to Miocene, tidal to wave-dominated, shallow deltaic to deep marine sediments of the Coaledo Delta. Coastal depositional environments are known to host source, reservoir, and seal rocks. Climate, topographic relief, and geographical position all play an important role in regional vegetation development and oceanic setting. This study assesses 84 outcrop and 12 core samples from Coos Bay for their organic geochemical characteristics and microfossil assemblage to provide source rock characterization information, organofacies descriptions, environmental reconstructions, and age control.

Results indicate the …


Lotic-Sipco2: Adaptation Of An Open-Source Co2 Sensor System And Examination Of Associated Emission Uncertainties Across A Range Of Stream Sizes And Land Uses, Andrew L. Robison, Lauren E. Koenig, Jody D. Potter, Lisle E. Snyder, Christopher W. Hunt, William H. Mcdowell, Wilfred M. Wollheim Feb 2024

Lotic-Sipco2: Adaptation Of An Open-Source Co2 Sensor System And Examination Of Associated Emission Uncertainties Across A Range Of Stream Sizes And Land Uses, Andrew L. Robison, Lauren E. Koenig, Jody D. Potter, Lisle E. Snyder, Christopher W. Hunt, William H. Mcdowell, Wilfred M. Wollheim

Faculty Publications

River networks play a crucial role in the global carbon cycle, as relevant sources of carbon dioxide (CO2) to the atmosphere. Advancements in high-frequency monitoring in aquatic environments have enabled measurement of dissolved CO2 concentration at temporal resolutions essential for studying carbon variability and evasion from these dynamic ecosystems. Here, we describe the adaptation, deployment, and validation of an open-source and relatively low-cost in situ pCO2 sensor system for lotic ecosystems, the lotic-SIPCO2. We tested the lotic-SIPCO2 in 10 streams that spanned a range of land cover and basin size. Key system adaptations for lotic environments included prevention of biofouling, …


College Of Natural Sciences 2023 Year-End Publication, College Of Natural Sciences Feb 2024

College Of Natural Sciences 2023 Year-End Publication, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 1 Dean's Message
Page 3 Department Highlights
Page 4 One Day for State
Page 5 Noble Prize Winner Speaks on Campus
Page 6-7 Faculty Excellence
Page 8-9 Student Excellence
Page 10 Outreach Program
Page 10 Events and Traditions
Page 11 Connections Abroad
Page 12 Student Spotlight
Page 13 Alumni Spotlight
Page 14 First Ever Drone Day
Page 15 Grand Opening of POET Bioproducts Center
Page 16 Work Anniversaries


Nanoscale Studies Of Magnesium Carbonate Precipitation At Ambient Conditions, Ian Shortt Jan 2024

Nanoscale Studies Of Magnesium Carbonate Precipitation At Ambient Conditions, Ian Shortt

Material Science and Engineering Dissertations - Archive

Currently approximately 8% of global greenhouse gas emissions can be attributed to the construction industry; of these emissions, a little over half of these emissions are due to the production of traditional calcium-based cements. Magnesium carbonate cements present a promising alternative to traditional calcium-based cements, both in terms of emission reductions and in terms of strength. The primary drawback to magnesium carbonate cements is that ambient curing is not yet viable. The objective of this dissertation is to therefore develop greater understanding of the precipitation pathways undertaken by hydrated magnesium carbonates under near-ambient conditions. In the first section of this …


Unlv Title Iii Aanapisi & Mcnair Scholars Institute Research Journal 2024, Jesica Godinez-Paredes, Kian Hassankhan, Apia Hickman, Robin Ruth Kee, Kevin Ayala Pineda, Briana Melendez, Kalli Ramos, Saturn L. Reyes, Fabian Leija, Selena Pepe, Silva Topchyan, Celeste Ainsley, Mayra Arzate, Jessica Balistreri, Zantana Ephrem, Mirella Jasso, Karl Panou, Nichole Pelaez, Miklo Alcala, Akshay Dave, Mey Mey Heng, Michael Finkle, Janessa Montenegro, Reynafe Naol Aniga, Victor Mejia, Angelica G. Diaz, Anayeli Flores-Garibay, Kari Lee Joe Goold, Samantha Hernandez, Lianelys Cabrera Martinez, Caitlin Reynolds, Kimberly N. Usbeck, Abdulrahman Alahdal, Angelica Diaz, Willaine Mae Kahano, Raquel Jackson, Cecia Ruiz-Hernandez, Kers Ung-Watson, Yessenia Henriquez, Vanessa Marie Booth, Alexia Brown, Darlyn Magana, Bianca Navarro, Nicholas Pereira, Gia Renemae Calip, Lucky Heng, Ralph Sagun, Lucas Abreu, Alexandra Maria Acosta, Tristan Benally, Cosset Hernandez Pena, Adrian Montenegro, Cierra Paaaina-Daquioag, Nicole Torosian, Tracy Fuentes, Julissa Martinez, Medina Mcallister, Michal Newhouse-Van Vlerin, Tiria Carr, Nima Abkenar, Isabella Aceituno, Yuhan Bi, Victoria Campos, Melika Cummings, Zachary J. Johnigan, Alexis Sotolongo-Marin Jan 2024

Unlv Title Iii Aanapisi & Mcnair Scholars Institute Research Journal 2024, Jesica Godinez-Paredes, Kian Hassankhan, Apia Hickman, Robin Ruth Kee, Kevin Ayala Pineda, Briana Melendez, Kalli Ramos, Saturn L. Reyes, Fabian Leija, Selena Pepe, Silva Topchyan, Celeste Ainsley, Mayra Arzate, Jessica Balistreri, Zantana Ephrem, Mirella Jasso, Karl Panou, Nichole Pelaez, Miklo Alcala, Akshay Dave, Mey Mey Heng, Michael Finkle, Janessa Montenegro, Reynafe Naol Aniga, Victor Mejia, Angelica G. Diaz, Anayeli Flores-Garibay, Kari Lee Joe Goold, Samantha Hernandez, Lianelys Cabrera Martinez, Caitlin Reynolds, Kimberly N. Usbeck, Abdulrahman Alahdal, Angelica Diaz, Willaine Mae Kahano, Raquel Jackson, Cecia Ruiz-Hernandez, Kers Ung-Watson, Yessenia Henriquez, Vanessa Marie Booth, Alexia Brown, Darlyn Magana, Bianca Navarro, Nicholas Pereira, Gia Renemae Calip, Lucky Heng, Ralph Sagun, Lucas Abreu, Alexandra Maria Acosta, Tristan Benally, Cosset Hernandez Pena, Adrian Montenegro, Cierra Paaaina-Daquioag, Nicole Torosian, Tracy Fuentes, Julissa Martinez, Medina Mcallister, Michal Newhouse-Van Vlerin, Tiria Carr, Nima Abkenar, Isabella Aceituno, Yuhan Bi, Victoria Campos, Melika Cummings, Zachary J. Johnigan, Alexis Sotolongo-Marin

McNair Journal

Journal articles based on research conducted by undergraduate students in the AANAPISI, LSAMP, and McNair Scholars Program.

Table of Contents

About AANAPISI

Dr. Chris Heavey, Interim President

Dr. Keith Rogers, Vice President for Student Affairs

Ms. Zhanna Aronov, Associate Vice President for Retention & Outreach


Editorial: The Marine Iodine Cycle, Past, Present, And Future, Rosie Chance, Gregory A. Cutter, Dalton S. Hardisty, Anoop S. Mahajan Jan 2024

Editorial: The Marine Iodine Cycle, Past, Present, And Future, Rosie Chance, Gregory A. Cutter, Dalton S. Hardisty, Anoop S. Mahajan

OES Faculty Publications

In this Research Topic, we bring together ten articles from the diverse research communities interested in the marine iodine cycle, including paleoceanographers, atmospheric chemists, and biogeochemists. The physical chemistry underpinning iodine’s chemical speciation and transformations in the ocean is reviewed by Luther; this paper provides a theoretical basis for the field observations presented in this Research Topic.


Marine Emissions Of Methanethiol Increase Aerosol Cooling In The Southern Ocean, Charel Wohl, Julián Villamayor, Martí Galí, Anoop S. Mahajan, Rafael P. Fernández, Carlos A. Cuevas, Adriana Bossolasco, Qinyi Li, Anthony J. Kettle, Tara Williams, Roland Sarda-Esteve, Valérie Gros, Rafel Simó, Alfonso Saiz-Lopez Jan 2024

Marine Emissions Of Methanethiol Increase Aerosol Cooling In The Southern Ocean, Charel Wohl, Julián Villamayor, Martí Galí, Anoop S. Mahajan, Rafael P. Fernández, Carlos A. Cuevas, Adriana Bossolasco, Qinyi Li, Anthony J. Kettle, Tara Williams, Roland Sarda-Esteve, Valérie Gros, Rafel Simó, Alfonso Saiz-Lopez

OES Faculty Publications

Ocean-emitted dimethyl sulfide (DMS) is a major source of climate-cooling aerosols. However, most of the marine biogenic sulfur cycling is not routed to DMS but to methanethiol (MeSH), another volatile whose reactivity has hitherto hampered measurements. Therefore, the global emissions and climate impact of MeSH remain unexplored. We compiled a database of seawater MeSH concentrations, identified their statistical predictors, and produced monthly fields of global marine MeSH emissions adding to DMS emissions. Implemented into a global chemistry-climate model, MeSH emissions increase the sulfate aerosol burden by 30 to 70% over the Southern Ocean and enhance the aerosol cooling effect while …


Unraveling Sources Of Cyanate In The Marine Environment: Insights From Cyanate Distributions And Production During The Photochemical Degradation Of Dissolved Organic Matter, Rui Wang, Jihua Liu, Yongle Xu, Li Liu, Kenneth Mopper Jan 2024

Unraveling Sources Of Cyanate In The Marine Environment: Insights From Cyanate Distributions And Production During The Photochemical Degradation Of Dissolved Organic Matter, Rui Wang, Jihua Liu, Yongle Xu, Li Liu, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

Cyanate is a nitrogen and energy source for diverse marine microorganisms, playing important roles in the nitrogen cycle. Despite the extensive research on cyanate utilization, the sources of this nitrogen compound remain largely enigmatic. To unravel the sources of cyanate, distributions and production of cyanate during photochemical degradation of natural dissolved organic matter (DOM) were investigated across various environments, including freshwater, estuarine, coastal areas in Florida, and the continental and slope regions of the North American mid-Atlantic Ocean (NATL). Cyanate production was also examined during the photochemical degradation of exudates from a typical strain of Synechococcus, an important phytoplankton …


Reducing The Uncertainty In Estimating Soil Microbial-Derived Carbon Storage, Han Hu, Chao Qian, Ke Xue, Rainer Georg Jörgensen, Marco Keiluweit, Chao Liang, Xuefeng Zhu, Ji Chen, Yishen Sun, Haowei Ni, Jixian Ding, Weigen Huang, Jingdong Mao, Rong-Xi Tan, Jizhong Zhou, Thomas W. Crowther, Zhi-Hua Zhou, Jiabao Zhang, Yuting Liang Jan 2024

Reducing The Uncertainty In Estimating Soil Microbial-Derived Carbon Storage, Han Hu, Chao Qian, Ke Xue, Rainer Georg Jörgensen, Marco Keiluweit, Chao Liang, Xuefeng Zhu, Ji Chen, Yishen Sun, Haowei Ni, Jixian Ding, Weigen Huang, Jingdong Mao, Rong-Xi Tan, Jizhong Zhou, Thomas W. Crowther, Zhi-Hua Zhou, Jiabao Zhang, Yuting Liang

Chemistry & Biochemistry Faculty Publications

Soil organic carbon (SOC) is the largest carbon pool in terrestrial ecosystems and plays a crucial role in mitigating climate change and enhancing soil productivity. Microbial-derived carbon (MDC) is the main component of the persistent SOC pool. However, current formulas used to estimate the proportional contribution of MDC are plagued by uncertainties due to limited sample sizes and the neglect of bacterial group composition effects. Here, we compiled the comprehensive global dataset and employed machine learning approaches to refine our quantitative understanding of MDC contributions to total carbon storage. Our efforts resulted in a reduction in the relative standard errors …


Potentially Massive And Global Non-Pyrogenic Production Of Condensed "Black" Carbon Through Biomass Oxidation, Aleksandar I. Goranov, Hongmei Chen, Jianshu Duan, Satish C. B. Myneni, Patrick G. Hatcher Jan 2024

Potentially Massive And Global Non-Pyrogenic Production Of Condensed "Black" Carbon Through Biomass Oxidation, Aleksandar I. Goranov, Hongmei Chen, Jianshu Duan, Satish C. B. Myneni, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the increased occurrences of wildfires worldwide, there has been an increase in scientific interest surrounding the chemistry of fire-derived "black" carbon (BC). Traditionally, wildfire research has assumed that condensed aromatic carbon (ConAC) is exclusively produced via combustion, and thus, ConAC is equated to BC. However, the lack of correlations between ConAC in soils or rivers and wildfire history suggests that ConAC may be produced non-pyrogenically. Here, we show quantitative evidence that this occurs during the oxidation of biomass with environmentally ubiquitous hydroxyl radicals. Pine wood boards exposed to iron nails and natural weather conditions for 12 years yielded a …


Wildfire Effects On The Fate Of Deposited Nitrogen In A Boreal Larch Forest, Weili Liu, Jiaxing Zu, B. Liu, Lin Qi, Wei Huang, Yunting Fang, Jian Yang Jan 2024

Wildfire Effects On The Fate Of Deposited Nitrogen In A Boreal Larch Forest, Weili Liu, Jiaxing Zu, B. Liu, Lin Qi, Wei Huang, Yunting Fang, Jian Yang

Earth and Environmental Sciences Faculty Publications

The effects of nitrogen (N) deposition on forests largely depend on the ecosystem N status and the fates of deposited N. Boreal forests are typically N-limited ecosystems and are considered to be more efficient in retaining deposited N relative to temper- ate and tropical forests. As a primary disturbance in boreal forests, wildfires may alleviate N limitation in the burned ecosystem and increase mineralization, resulting in the altered outcomes of the N deposition.


Novel Re-Crosslinkable Preformed Particle Gels (Rppg) For Parent- And Infill-Well-Fracture Interactions Mitigation, Xiaojing Ge, Adel Alotibi, Ahmed Al-Hlaichi, Yanbo Liu, Tao Song, Junchen Liu, Baojun Bai, Thomas P. Schuman Jan 2024

Novel Re-Crosslinkable Preformed Particle Gels (Rppg) For Parent- And Infill-Well-Fracture Interactions Mitigation, Xiaojing Ge, Adel Alotibi, Ahmed Al-Hlaichi, Yanbo Liu, Tao Song, Junchen Liu, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Hydraulic fracturing treatments in unconventional infill (or "child") wells can be significantly affected by depletion from existing parent-well, resulting in asymmetrical fracture growth. These issues may lead to excessive load-water production, proppant deposition, casing deformation in the parent well, and unbalanced stimulation of infill wells. To mitigate these effects, various strategies have been proposed, including the use of far-field diverters in child wells and repressurization of parent wells. Additionally, an increasingly popular strategy involves injecting near-wellbore diverters to temporarily plug entry points into the parent wellbores during frac operations on infill wells. To achieve better application, a novel low-cost, self-degradable, …


Plasmid-Borne Biosynthetic Gene Clusters Within A Permanently Stratified Marine Water Column, Paraskevi Mara, David Geller-Mcgrath, Elizabeth A. Suter, Gordon T. Taylor, Maria G. Pachiadaki, Virginia P. Edgcomb Jan 2024

Plasmid-Borne Biosynthetic Gene Clusters Within A Permanently Stratified Marine Water Column, Paraskevi Mara, David Geller-Mcgrath, Elizabeth A. Suter, Gordon T. Taylor, Maria G. Pachiadaki, Virginia P. Edgcomb

BCES: Faculty Publications

Plasmids are mobile genetic elements known to carry secondary metabolic genes that affect the fitness and survival of microbes in the environment. Well-studied cases of plasmidencoded secondary metabolic genes in marine habitats include toxin/antitoxin and antibiotic biosynthesis/resistance genes. Here, we examine metagenome-assembled genomes (MAGs) from the permanently-stratified water column of the Cariaco Basin for integrated plasmids that encode biosynthetic gene clusters of secondary metabolites (smBGCs). We identify 16 plasmid-borne smBGCs in MAGs associated primarily with Planctomycetota and Pseudomonadota that encode terpenesynthesizing genes, and genes for production of ribosomal and non-ribosomal peptides. These identified genes encode for secondary metabolites that are …


Supply And Consumption Of Dissolved Organic Phosphorus Across The Subtropical Indian Ocean, Corinne Richard Jan 2024

Supply And Consumption Of Dissolved Organic Phosphorus Across The Subtropical Indian Ocean, Corinne Richard

Honors Theses and Capstones

The Indian Ocean is an understudied region for marine phosphorus (P) biogeochemistry. Emerging evidence indicates marine phytoplankton can adapt to decreasing supplies of inorganic P, a required nutrient for growth, by alternatively utilizing organic forms of P. Here we investigate the dissolved organic phosphorus concentration ([DOP]) distribution across the southern Indian Ocean using observations collected on the I05 US GO-SHIP Cruise (2023) across ~33ºS latitude. We quantify the longitudinal variability of [DOP] in the upper 350 m of the Indian Ocean and infer its rate of biological consumption from surface waters, contributing as an organic nutrient to sustain marine autotrophs …


Permafrost Carbon: Progress On Understanding Stocks And Fluxes Across Northern Terrestrial Ecosystems, Claire C. Treat, Anna-Maria Virkkala, Eleanor Burke, Lori Bruhwiler, Abhishek Chatterjee, Joshua B. Fisher, Josh Hashemi, Frans-Jan W. Parmentier, Brendan M. Rogers, Sebastian Westermann, Jennifer D. Watts, Elena Blanc-Betes, Matthias Fuchs, Stefan Kruse, Avni Malhotra, Kimberley Miner, Jens Strauss, Amanda Armstrong, Howard E. Epstein, Bradley Gay, Mathias Goeckede, Aram Kalhori, Dan Kou, Charles E. Miller, Susan M. Natali, Youmi Oh, Sarah Shakil, Oliver Sonnentag, Ruth K. Varner, Scott Zolkos, Edward A.G. Schuur, Gustaf Hugelius Jan 2024

Permafrost Carbon: Progress On Understanding Stocks And Fluxes Across Northern Terrestrial Ecosystems, Claire C. Treat, Anna-Maria Virkkala, Eleanor Burke, Lori Bruhwiler, Abhishek Chatterjee, Joshua B. Fisher, Josh Hashemi, Frans-Jan W. Parmentier, Brendan M. Rogers, Sebastian Westermann, Jennifer D. Watts, Elena Blanc-Betes, Matthias Fuchs, Stefan Kruse, Avni Malhotra, Kimberley Miner, Jens Strauss, Amanda Armstrong, Howard E. Epstein, Bradley Gay, Mathias Goeckede, Aram Kalhori, Dan Kou, Charles E. Miller, Susan M. Natali, Youmi Oh, Sarah Shakil, Oliver Sonnentag, Ruth K. Varner, Scott Zolkos, Edward A.G. Schuur, Gustaf Hugelius

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Significant progress in permafrost carbon science made over the past decades include the identification of vast permafrost carbon stocks, the development of new pan-Arctic permafrost maps, an increase in terrestrial measurement sites for CO2 and methane fluxes, and important factors affecting carbon cycling, including vegetation changes, periods of soil freezing and thawing, wildfire, and other disturbance events. Process-based modeling studies now include key elements of permafrost carbon cycling and advances in statistical modeling and inverse modeling enhance understanding of permafrost region C budgets. By combining existing data syntheses and model outputs, the permafrost region is likely a wetland methane …


Celestial Bodies, Rebecca L. Rand, Mark Popinchalk Dec 2023

Celestial Bodies, Rebecca L. Rand, Mark Popinchalk

Capstones

Most of us will never come close to touching space. But space touches us every day. On Celestial Bodies, journalist Rebecca Rand and astronomer Mark Popinchalk explore the ways outer space interacts with life on earth.

In Episode 1, hosts Rebecca Rand and Mark Popinchalk explore how, for millions of years, trees have been recording celestial events in space. Within the rings of their trunks, trees store radiation from solar flares, supernovae, and changes in the earth’s magnetic field. The hosts talk to Dr. Ben Pope to learn more about what we can discover by looking at radioactive molecules …


Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy Nov 2023

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km2 and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …


Inhibition Of Chromium(Iii) Oxidation Through Manganese(Iv) Oxide Passivation And Iron(Ii) Abiotic Reduction, Miranda L. Aiken, Macon J. Abernathy, Michael V. Schaefer, Ilkeun Lee, Samantha C. Ying Nov 2023

Inhibition Of Chromium(Iii) Oxidation Through Manganese(Iv) Oxide Passivation And Iron(Ii) Abiotic Reduction, Miranda L. Aiken, Macon J. Abernathy, Michael V. Schaefer, Ilkeun Lee, Samantha C. Ying

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Manganese (Mn) oxides are strong oxidants that are ubiquitous in soils and can oxidize redox-active metals, including chromium (Cr). In soil environments, trivalent chromium (Cr(III)) is a benign, immobile micronutrient, whereas the hexavalent Cr(VI) form is present as a highly mobile, toxic chromate oxyanion. Although many studies have characterized the capacity of Mn(III/IV) oxides to oxidize Cr(III) to toxic Cr(VI), the oxidative capacity of Mn oxides in the presence of potentially passivating soil constituents, specifically reduced soluble iron (Fe(II)aq), remains unresolved. We hypothesized that chemical processes at redox interfaces, such as diffusion-limited environments within soil aggregates, can lead to decreased …


Volcanic Diffuse Volatile Emissions Tracked By Plant Responses Detectable From Space, Robert R. Bogue, Peter M. J. Douglas, Joshua B. Fisher, John Stix Nov 2023

Volcanic Diffuse Volatile Emissions Tracked By Plant Responses Detectable From Space, Robert R. Bogue, Peter M. J. Douglas, Joshua B. Fisher, John Stix

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Volcanic volatile emissions provide information about volcanic unrest but are difficult to detect with satellites. Volcanic degassing affects plants by elevating local CO2 and H2O concentrations, which may increase photosynthesis. Satellites can detect plant health, or a reaction to photosynthesis, through a Normalized Difference Vegetation Index (NDVI). This can act as a potential proxy for detecting changes in volcanic volatile emissions from space. We tested this method by analyzing 185 Landsat 5 and 8 images of the Tern Lake thermal area (TLTA) in northeast Yellowstone caldera from 1984 to 2022. We compared the NDVI values of the thermal area with …


Assessment Of Viability Of Coal Mines In Tanzania For Extraction Of Rare Earth Elements, Juma Sija, Mohamed Mazunga Oct 2023

Assessment Of Viability Of Coal Mines In Tanzania For Extraction Of Rare Earth Elements, Juma Sija, Mohamed Mazunga

Tanzania Journal of Science

This study aimed at determining the concentrations of rare earth elements (REEs) in coal and coal fly ash (CFA) from three coal mines in Tanzania: Kiwira, Ngaka and Rukwa. The goal was to assess if these resources could be commercially viable for extracting REEs. Coal and CFA samples were analysed using X-ray fluorescence (XRF) spectrometry and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The total concentrations of REEs in the coal samples ranged from 89.48 parts per million (ppm) to 196.30 ppm, while in CFA samples, ranged from 362.55 ppm to 475.77 ppm. Computed percentage of critical REEs (REYdef, …


College Of Natural Sciences Newsletter, September - October 2023, College Of Natural Sciences Oct 2023

College Of Natural Sciences Newsletter, September - October 2023, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 1 Dean's Message
Page 2 New Faculty an Staff for the Fall 2023 Semester
Page 3 Awards
Page 4 Student Ambassadors in CNS
Page 5 Meet our Jacks
Page 6-8 Events
Page 9-11 Media Coverage of CNS
Page 12-13 Spring 2023 Dean's List
Page 14 Open PRAIRIE Data