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Full-Text Articles in Environmental Chemistry

Synthesis And Characterization Of Carbon Quantum Dots And Gold Nanoparticles For Norovirus Biosensing Applications In Water Systems, Breanne Evans Aug 2026

Synthesis And Characterization Of Carbon Quantum Dots And Gold Nanoparticles For Norovirus Biosensing Applications In Water Systems, Breanne Evans

Master's Theses

Rapid, reliable detection of viral pathogens remains a significant challenge across water-treatment and environmental monitoring systems, including drinking-water, wastewater, water reuse, and environmental surveillance applications. Waterborne viral contamination can pose substantial public-health risks, making early detection essential for protecting water quality and responding quickly to treatment failures or contamination events. Direct potable reuse (DPR) is one particularly demanding example because it requires continuous verification of treatment performance and the broader need for rapid virus monitoring extends across many water-treatment and environmental surveillance applications. Norovirus is a priority target because of its widespread occurrence in wastewater, environmental persistence, and exceptionally low …


Tissue-Specific Heavy Metal Accumulation And Sediment–Mangrove Dynamics In Port Everglades, Florida, Dimitrios Giarikos, Amy Hirons, Jason Gershman, Sophie Welch May 2026

Tissue-Specific Heavy Metal Accumulation And Sediment–Mangrove Dynamics In Port Everglades, Florida, Dimitrios Giarikos, Amy Hirons, Jason Gershman, Sophie Welch

SECLER Data

Coastal wetlands near industrialized waterways face increasing heavy metal contamination, yet the role of mangroves as biogeochemical buffers remains poorly understood. This study quantified 16 heavy metals in sediments and red mangrove (Rhizophora mangle) tissues (roots, branches, and leaves) across four sites near Port Everglades, Florida, examining tissue-specific partitioning, contamination patterns, and sediment-to-plant transfer. The South Turning Basin (STB) was the principal contamination hotspot, with geometric mean (GM) concentrations of arsenic (As; 27.8 µg/g) and zinc (Zn; 203 µg/g) exceeding threshold effect levels, while Cu exceeded its probable effect level (PEL; 193 µg/g). Mercury (Hg) exceeded its PEL …


Chemometric Analysis Of Dissolved Organic Matter Using Fluorescence, Dani Fellner, Ken Overway May 2026

Chemometric Analysis Of Dissolved Organic Matter Using Fluorescence, Dani Fellner, Ken Overway

Honors Projects

Univariate spectroscopic techniques have been utilized to measure dissolved organic matter (DOM), but challenges arise in the separation and characterization due to similarities in chemical structures and spectral overlap. Multivariate techniques utilize a combination of known analytes with their unique excitation and emission spectra from fluorescence measurements to quantify amount of each analyte present in the mixture using parallel factor analysis. Tryptophan, tyrosine, and phenylalanine are common amino acids found in environmental samples and can be quantified due to their intrinsic fluorescence qualities. These amino acids can be utilized to estimate the amount of DOM in a sample since proteins …


Targeting Chemical Pollutants Through Assimilation Of Hydrophobic Deep Eutectic Solvents With Metal-Organic Frameworks, Carbon Nanotubes, And Activated Carbon, Tanner William Baughman Apr 2026

Targeting Chemical Pollutants Through Assimilation Of Hydrophobic Deep Eutectic Solvents With Metal-Organic Frameworks, Carbon Nanotubes, And Activated Carbon, Tanner William Baughman

ONU Student Research Colloquium

Water contamination by heavy metals has a harmful human threat to the environment and to human health. This is derived from their bioaccumulation and toxicity characteristics. The study directly looks at the assimilated of lignin-derived hydrophobic deep eutectic solvents (HDES) with 3 different class of materials: Metal-Organic Frameworks (MOFs), Carbon Nanotubes (CNTs), and Activated Carbon (AC). Four different HDES mixtures were assimilated into these porous materials through impregnation. Composites were evaluated by characteristic peaks through Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The morphology of the samples was assessed as well through scanning electron microscopy (SEM). The colloidal stability …


Monitoring Of Dissolved Calcium Levels In Creeks, Embayment, And Kentucky Lake Waters In Western Kentucky, Majeda Dalloul Apr 2026

Monitoring Of Dissolved Calcium Levels In Creeks, Embayment, And Kentucky Lake Waters In Western Kentucky, Majeda Dalloul

Scholars Week

In order to reduce the economic and ecological impacts of aquatic alien species, studies are warranted across major taxonomic groups, geographic regions, and habitat types. This study addressed the dissolved calcium levels in Kentucky Lake and their implications for one of the top-ranked invasive species, the zebra mussel, and its colonization.  Zebra mussels (Dreissena polymorpha) are well known for their “biofouling” capabilities, costing billions of dollars (for northeastern and midwestern states) in their removal from industrial, public, and power plant water supply lines. Calcium is one of the essential elements that contribute to the growth and reproduction of zebra …


Advancing Environmental Justice Through Chemical Education: Perspective From New Orleans’ Water And Air Quality Challenges, Ja’Lynn Keller, Sita Aggarwal, Rami A. Al-Horani, Morewell Gasseller, Navneet Goyal Mar 2026

Advancing Environmental Justice Through Chemical Education: Perspective From New Orleans’ Water And Air Quality Challenges, Ja’Lynn Keller, Sita Aggarwal, Rami A. Al-Horani, Morewell Gasseller, Navneet Goyal

Faculty and Staff Publications

New Orleans, Louisiana, faces profound environmental vulnerabilities arising from the convergence of industrial pollution, urban runoff, and climate change–driven weather events. This paper examines systemic challenges affecting water and air quality in the region, with particular focus on low-income and marginalized communities disproportionately burdened by environmental degradation. Drawing on educational and community-based monitoring initiatives at Xavier University of Louisiana and Southeastern Louisiana University, we highlight the integration of student learning with real-time data collection of contaminants such as fecal coliforms, heavy metals, hydrocarbons, and polycyclic aromatic hydrocarbons (PAHs). The aftermath of Hurricane Katrina revealed significant fecal contamination in sediment layers, …


Peruvian Pinniped Teeth Trace Element Data-Tracking Ecosystem Variabilites Through Trace Element Record Found In Peruvian Pinniped Dentin, Dimitrios Giarikos, Amy Hirons, Ally E. Sheehan, Radleigh Santos Mar 2026

Peruvian Pinniped Teeth Trace Element Data-Tracking Ecosystem Variabilites Through Trace Element Record Found In Peruvian Pinniped Dentin, Dimitrios Giarikos, Amy Hirons, Ally E. Sheehan, Radleigh Santos

SECLER Data

The South American sea lion (Otaria byronia; SASL) and the Peruvian fur seal (Arctocephalus australis; PFS) are apex predators within the Humboldt Current ecosystem, where population dynamics respond to both natural variability and anthropogenic pressures, including El Niño–Southern Oscillation (ENSO) events and coastal mining. This study quantified 18 trace elements (TEs) in canine dentin from both species collected at Punta San Juan, Peru using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to evaluate long-term environmental exposure. Because dentin is deposited incrementally, it preserves a chronological chemical archive reflecting ontogenetic shifts in diet and habitat use. Overall, TE concentrations were broadly similar …


Long-Term Variability Of Air Quality And Greenhouse Gas Emissions From Rice Crop Burning In Punjab During 2012–2020, Harsimranjit Kaur Romana, Dericks Praise Shukla, Ramesh P. Singh Mar 2026

Long-Term Variability Of Air Quality And Greenhouse Gas Emissions From Rice Crop Burning In Punjab During 2012–2020, Harsimranjit Kaur Romana, Dericks Praise Shukla, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

Punjab, India's primary rice and wheat production hub, has witnessed rapid expansion of paddy cultivation over the past two decades, driven by minimum support price incentives, changes in government policies, alignment of sowing with the monsoon season and the adoption of high-yielding varieties. This transition has intensified groundwater extraction and shortened the fallow period between rabi and kharif crop seasons, reducing the window between rice harvesting and wheat sowing, leading to widespread open-field burning of rice residue and recurrent post-monsoon air-quality deterioration across the Indo-Gangetic Plain. Despite numerous short-term or single-pollutant assessments, a spatially resolved, multi-pollutant and multi-decadal evaluation linking …


A Probabilistic Deep Learning Framework For Retrieving Chlorophyll-A From Hyperspectral Imagery: Integrating Channel Attention And Mixture Density Networks, Wenzhao Li, Surendra Maharjan, Rejoice Thomas, Junde Chen, Hesham Morgan, Michael J. Garay, Olga V. Kalashnikova, Shahryar Fazli, Charles Ichoku, Hesham El-Askary Feb 2026

A Probabilistic Deep Learning Framework For Retrieving Chlorophyll-A From Hyperspectral Imagery: Integrating Channel Attention And Mixture Density Networks, Wenzhao Li, Surendra Maharjan, Rejoice Thomas, Junde Chen, Hesham Morgan, Michael J. Garay, Olga V. Kalashnikova, Shahryar Fazli, Charles Ichoku, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Accurate monitoring of Chlorophyll-a (Chla) is critical for assessing aquatic ecosystem health, yet ecological complexity often leads to ambiguous spectral signatures in satellite data. Traditional deterministic models assume a one-to-one mapping between spectra and pigments, often failing to capture these high-dimensional analytical challenges. In this study, we propose a novel deep learning architecture, the Channel Attention-Mixture Density Network (CA-MDN), to retrieve Chla from the National Aeronautics and Space Administration (NASA) Earth Surface Mineral Dust Source Investigation (EMIT) hyperspectral mission. The CA-MDN integrates an attention mechanism to dynamically select ecologically relevant spectral bands and employs a probabilistic output layer to quantify …


Development Trends And Implications Of Muti-Objective Marine Environmental Forecasting Technology, Yineng Li, Yuhang Zhu, Shiqiu Peng, Zhiwu Chen, Xing Wei, Junmin Li, Shaodian Li, Peiwei Xie, Jiawen Liao, Yankun Gong, Shilin Tang, Shuqun Cai Jan 2026

Development Trends And Implications Of Muti-Objective Marine Environmental Forecasting Technology, Yineng Li, Yuhang Zhu, Shiqiu Peng, Zhiwu Chen, Xing Wei, Junmin Li, Shaodian Li, Peiwei Xie, Jiawen Liao, Yankun Gong, Shilin Tang, Shuqun Cai

Bulletin of Chinese Academy of Sciences (Chinese Version)

With the continuous expansion of global maritime activities and the steady advancement of the “maritime power” strategy, marine environmental security has become a top priority for China. In deep-sea areas, various environmental parameters such as temperature, salinity, sound velocity, wave dynamics, internal solitary waves, and nearshore rip currents play a crucial role in navigation safety and underwater equipment operations. Nevertheless, traditional single-parameter forecasting models are no longer sufficient to meet the demands of multi-objective environmental protection. As a result, there is a growing need for a high-resolution, multi-objective forecasting system that integrates basic oceanographic element predictions (such as temperature, salinity, …


Current Status And Prospects Of Ocean Data Reanalysis, Chuanyu Liu, Fan Wang Jan 2026

Current Status And Prospects Of Ocean Data Reanalysis, Chuanyu Liu, Fan Wang

Bulletin of Chinese Academy of Sciences (Chinese Version)

Ocean data reanalysis (ODR) is a technique that combines ocean observational data with ocean circulation models to produce gridded data with higher accuracy and greater spatiotemporal coverage. The generated reanalysis data serve as a foundational dataset for conducting oceanographic research and developing artificial intelligence-based large ocean models. This study reviews the technical approaches of ODR, the current status of global and regional ocean data reanalysis systems developed in the world, and puts forward recommendations for the development of China's ocean reanalysis system.


Frontiers In Ocean Non-Equilibrium Dynamics And Challenges In Operational Oceanography Application, Yuhong Zhang, Yan Du, Tianyu Wang, Minyang Wang, Qin Duan, Xinlong Li, Yuhang Zheng, Yifan Xia, Shilin Tang, Yineng Li, Jianping Yin Jan 2026

Frontiers In Ocean Non-Equilibrium Dynamics And Challenges In Operational Oceanography Application, Yuhong Zhang, Yan Du, Tianyu Wang, Minyang Wang, Qin Duan, Xinlong Li, Yuhang Zheng, Yifan Xia, Shilin Tang, Yineng Li, Jianping Yin

Bulletin of Chinese Academy of Sciences (Chinese Version)

Ocean circulation exhibits complex multiscale dynamics, among which non-equilibrium processes, marked by transient behavior, strong perturbations, and pronounced nonlinearity, are of particular importance for maritime environmental support. However, limited observational capability has long constrained the study of subsurface non-equilibrium dynamics, leaving numerical models insufficiently validated and positioning this issue at the forefront of modern physical oceanography. Artificial intelligence (AI) offers a promising pathway to overcome this bottleneck. Built on this concept, the “iEddy” AI large ocean model can efficiently reconstruct high-resolution, high-accuracy three-dimensional temperature, salinity, and velocity from sea-surface remote sensing data, demonstrating strong capability in capturing non-equilibrium ocean currents …


Satellite-Derived Bathymetry In Island Coastal Zones: Technology, Shilin Tang, Yuye Huang, Yongming Liu, Jianping Yin, Deke Chen, Ronggang Huang, Shuang Li Jan 2026

Satellite-Derived Bathymetry In Island Coastal Zones: Technology, Shilin Tang, Yuye Huang, Yongming Liu, Jianping Yin, Deke Chen, Ronggang Huang, Shuang Li

Bulletin of Chinese Academy of Sciences (Chinese Version)

Shallow bathymetry data constitute the core foundational information underpinning the ecological, resource, and strategic values of island and coastal zones. Satellite-derived bathymetry has evolved into a key technical means for large-scale acquisition of shallow bathymetry information. Focusing on satellite-based lidar bathymetry, optical imaging bathymetry, and synthetic aperture radar (SAR) bathymetry, this study systematically summarizes the core principles, applicable scenarios, technical strengths, and inherent limitations of each technology. It is shown that satellite-derived bathymetry has undergone an evolutionary shift from theoretical construction to practical application, and from single-method, single-data-source approaches to multi-technology, multi-source data fusion frameworks. In the future, to meet …


Innovative Applications And Development Paths Of Digital Earth Technology In Marine Environmental Support, Junyi Liu, Xiongfei Liu, Zongji Wang, Zhihong Zeng, Huiping Xie, Siye Liu Jan 2026

Innovative Applications And Development Paths Of Digital Earth Technology In Marine Environmental Support, Junyi Liu, Xiongfei Liu, Zongji Wang, Zhihong Zeng, Huiping Xie, Siye Liu

Bulletin of Chinese Academy of Sciences (Chinese Version)

The convergence of Digital Earth technologies and the field of marine environmental support represent a significant trend in global scientific and technological advancement. In response to the characteristics of marine environmental data such as sparsity, dynamic complexity, and multi-scale interdependence, and by integrating the evolution of international Digital Earth technology with China’s independent innovation practices, this study constructs three core methodological paradigms. The first is the element-integrated ontology, which proposes a hybrid representation paradigm of “spatiotemporal embedded field + ontology” to achieve integrated and dynamically evolving modeling of marine physical environments alongside geological, biological, chemical, and other multidimensional elements. The …


Transparent West-Pacific: Frontier Advances In Earth System Science, Lixin Wu, Jiwei Tian, Weidong Sun, Hailong Liu, Tianyu Chen, Zhimian Cao, Zhao Jing Jan 2026

Transparent West-Pacific: Frontier Advances In Earth System Science, Lixin Wu, Jiwei Tian, Weidong Sun, Hailong Liu, Tianyu Chen, Zhimian Cao, Zhao Jing

Bulletin of Chinese Academy of Sciences (Chinese Version)

The West-Pacific hosts a well-developed trench-arc-basin system characterized by intense fluid–solid interactions, making it an ideal region for studying multi-sphere interactions within the Earth system. Research on cross-sphere dynamic processes and material-energy cycles in the West-Pacific not only represents a core frontier in Earth System Science, but also crucial to addressing major strategic needs, such as global climate change response, sustainable use of marine resources, and protection of the deep-sea environment. This article highlights key advances achieved under the Major Program on West-Pacific Earth System Multispheric Interactions (WESPMI), in areas including multi-scale oceanic interactions, cross-sphere material exchange, plate subduction and …


Application Of Organic Geochemistry To The Characterization Of Hydrochar And Biochar: Insights Into Composition And Optimization, Michael A. Kruge, Teresa A. Centeno, Alvaro Amado-Fierro, José Manuel González-Lafuente, Rubén Forján, José Luis Gallego Jan 2026

Application Of Organic Geochemistry To The Characterization Of Hydrochar And Biochar: Insights Into Composition And Optimization, Michael A. Kruge, Teresa A. Centeno, Alvaro Amado-Fierro, José Manuel González-Lafuente, Rubén Forján, José Luis Gallego

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Hydrothermal carbonization has garnered significant attention in recent studies due to potential applications of the hydrochar produced, which overlap with those of torrefied biochar, including soil improvement, carbon sequestration, and energy production. However, unlike the relatively uniform properties of biochar, hydrochar characteristics can vary greatly depending on the feedstock used. Advanced characterization techniques are essential to better understand these materials and enhance their practical applications. Research on hydrochar requires a multi-faceted approach, including molecular-level studies, to optimize production processes and identify specific applications.

In this regard, analytical methods commonly used in organic geochemistry could play a crucial role in deepening …


Feasibility Of Upcycling Spent Lithium-Ion Battery To Carbon Dioxide Capture Adsorbent, Chimezie Frank Onwudinjo Jan 2026

Feasibility Of Upcycling Spent Lithium-Ion Battery To Carbon Dioxide Capture Adsorbent, Chimezie Frank Onwudinjo

Master’s Theses

This study investigates the feasibility of repurposing spent lithium-ion battery (SLIB) to lithium orthosilicate (Li4SiO4), a high temperature carbon dioxide sorbent. Two synthesis pathways including conventional acid-leaching method (Scenario 1) and a pyrolysis-based route (Scenario 2) were explored. Additionally, techno-economic analysis (TEA) and lifecycle assessment (LCA) of the two processes were also performed. Different analytical characterization techniques were performed to understand the material properties of Li4SiO4 including surface area, crystallinity, morphology and thermal stability. CO2 capture performance of the synthesized Li4SiO4 was tested in a thermogravimetric analyzer (TGA) using …


Novel Methods For Environmental Fluoride Measurement, Cable Warren Jan 2026

Novel Methods For Environmental Fluoride Measurement, Cable Warren

Chemistry & Biochemistry Dissertations

Fluoride analysis has been an important focus of analytical analysis for many years and will continue to be so going forward. Today, fluorinated compounds, specifically per/polyfluoroalkyl substances (PFAS), better known as “forever chemicals” have captured the moment and are the subject of vast research and regulation. Under this context, I have researched new methods of fluoride separation and concentration in complex media as well as a novel method of PFAS destruction and total organic fluorine analysis for screening of PFAS in aqueous samples. Through research and work on micro-scale detection methods, an understanding of the state of the art and …


Pipeline Corrosion And Relevant Microbial Influence, Renee E. Bamberger Jan 2026

Pipeline Corrosion And Relevant Microbial Influence, Renee E. Bamberger

Williams Honors College, Honors Research Projects

This study investigated the role of microbial activity and oxygen availability in the corrosion of carbon steel pipelines with a focus on microbially influenced corrosion (MIC). Sediment collected from Old Woman Creek, Ohio, was used to simulate natural soil conditions, and carbon steel coupons were incubated under four treatments: nonsterile oxic, nonsterile anoxic, autoclaved oxic, and autoclaved anoxic over 85 days. Corrosion was assessed through mass loss measurements and the analysis of pH, sulfate, chloride, and dissolved iron concentrations. The greatest mass loss was observed in autoclaved oxic conditions, contrary to the initial hypothesis that microbial activity would greatly enhance …


Analysis Of Δ¹¹B As A Seawater Ph Proxy: Comparing Ocean Circulation Inverse Model Output With Marine Calcifier Geochemistry, Jesse I. Dong Jan 2026

Analysis Of Δ¹¹B As A Seawater Ph Proxy: Comparing Ocean Circulation Inverse Model Output With Marine Calcifier Geochemistry, Jesse I. Dong

CMC Senior Theses

Increasing anthropogenic carbon flux into the oceans decreases seawater pH, alters dissolved inorganic carbon speciation, and reduces biogenic calcification. The marine calcifiers— specifically corals and coralline algae—incorporate elements from surrounding seawater into their carbonate structures, which preserve past records of ocean carbon chemistry. In particular, boron in biogenic carbonate is a potentially valuable proxy for historical ocean pH across human timescales. Within seawater, boron primarily exists as boric acid B(OH)3 and borate ions B(OH)4 - , where higher pH favors the formation of borate ions. Borate ions preferentially incorporate the heavier ¹¹B isotope over 10B. On the other hand, if …


A Geospatial Assessment Of Groundwater Salinization In A Multi-Aquifer System: Durango, Mexico, Juan Lopez-Sierra Jan 2026

A Geospatial Assessment Of Groundwater Salinization In A Multi-Aquifer System: Durango, Mexico, Juan Lopez-Sierra

Graduate Theses/Dissertations

Groundwater salinization poses a critical environmental concern for water resource sustainability in arid and semi-arid regions. This study evaluates spatial and temporal patterns of groundwater salinity across the state of Durango, Mexico, using total dissolved solids (TDS), sodium adsorption ratio (SAR), as salinity indicators and nitrate-nitrogen (NO₃–N) as an anthropogenic indicator. Groundwater quality data were obtained from (CONAGUA), a Mexican water agency. To assess salinity variations with respect to time, while minimizing interannual sampling bias, two multi-year sampling periods were selected: 2012-2013, and 2020-2021. Final datasets consisted of 122 wells for 2012–2013 and 131 wells for 2020–2021. The wells were …


De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis Jan 2026

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …


Swimming In Uncertainty: Filling Data Gaps And Providing An Educational Platform For Beach Water Quality At Tybee Island, Georgia, Lukas Roberson Jan 2026

Swimming In Uncertainty: Filling Data Gaps And Providing An Educational Platform For Beach Water Quality At Tybee Island, Georgia, Lukas Roberson

College of Graduate Studies: Theses & Dissertations

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Swimming in beaches water contaminated with high levels of bacteria can make you sick. Current monitoring at the public beaches on Tybee Island consists of weekly monitoring and enumeration of fecal indicator bacteria that takes 24 hours for results. If the number of bacteria exceed regulatory limits, a public health advisory is issued, and affected waters are retested until …


Climate And Environmental Controls On Forest Soil Organic Matter Cycling, Genevieve Goebel Jan 2026

Climate And Environmental Controls On Forest Soil Organic Matter Cycling, Genevieve Goebel

Dartmouth College Ph.D Dissertations

Climate change factors act on the soil environment in complex ways, known to disturb soil organic carbon (C). Rising global temperatures and alterations to regional precipitation and nitrogen deposition regimes may contribute to the intensification of global change by accelerating the rate of biological decomposition and CO2 efflux to the atmosphere. The magnitude and endurance of the disturbance to soil organic C across landscapes and throughout time that climate change factors may pose to soil C cycling are not comprehensively understood. These knowledge gaps in our field make it challenging to anticipate how soil environments and the vast ecosystems that …


Assessing Dissolved Organic Matter Sources And Dynamics In Urban Stormwater: Implications For Greenhouse Gases, Harper W. Schmalz Jan 2026

Assessing Dissolved Organic Matter Sources And Dynamics In Urban Stormwater: Implications For Greenhouse Gases, Harper W. Schmalz

Theses and Dissertations (Comprehensive)

Stormwater management ponds (SWMPs) are important aspects of land-use planning and increasingly recognized as active sites of biogeochemical processing that influence carbon cycling; however, little research has investigated the controls on dissolved organic and dissolved inorganic carbon (DOC and DIC) within these systems. This thesis examined the processing and transformations of dissolved carbon between three compartments to support the development of a greenhouse gas (GHG) box-model for urban stormwater ponds, including SWMP sediment, surface water, and vegetation. The objective of this thesis was to assess the biogeochemical processes that govern the rate and transformation of DOC and DIC between these …


Dramatic Biases In Terrestrial Nitrogen Fixation In Earth System Models Revealed By Natural Isotope Signatures, Maoyuan Fang, Shushi Peng, Philippe Ciais, Daniel S. Goll, Benjamin Z. Houlton, Ying-Ping Wang, Yilong Wang, Pan Liu, Joshua B. Fisher, Pierre Regnier Oct 2025

Dramatic Biases In Terrestrial Nitrogen Fixation In Earth System Models Revealed By Natural Isotope Signatures, Maoyuan Fang, Shushi Peng, Philippe Ciais, Daniel S. Goll, Benjamin Z. Houlton, Ying-Ping Wang, Yilong Wang, Pan Liu, Joshua B. Fisher, Pierre Regnier

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Biological nitrogen fixation (BNF) is the primary input of new reactive nitrogen to natural terrestrial ecosystems. However, this flux is poorly constrained due to its unclear drivers and associated control mechanisms. Here, we extend the existing theory of nitrogen (N) isotope mass balance to estimate BNF rates and then use a Bayesian approach to constrain the BNF rates in natural terrestrial ecosystems by using measurements of natural N-isotope ratios (δ15N) in plants (δP) and soil (δS). Together with pairwise δP and δS measurements from 18 forest sites covering diverse climates and thousands …


Day-Night Shifts In Water-Soluble Ions Of Size-Resolved Aerosols Before And After The Covid-19 Lockdown In A Coastal Megacity: Metro Manila, Philippines, Grace Betito, Paola Angela Bañaga, Rachel A. Braun, Maria Obiminda Cambaliza, Melliza Templonuevo Cruz, Alexander B. Macdonald, James Bernard Simpas, Connor Stahl, Armin Sooroshian Oct 2025

Day-Night Shifts In Water-Soluble Ions Of Size-Resolved Aerosols Before And After The Covid-19 Lockdown In A Coastal Megacity: Metro Manila, Philippines, Grace Betito, Paola Angela Bañaga, Rachel A. Braun, Maria Obiminda Cambaliza, Melliza Templonuevo Cruz, Alexander B. Macdonald, James Bernard Simpas, Connor Stahl, Armin Sooroshian

SOSE Affiliate: Manila Observatory

The COVID-19 pandemic-driven lockdowns offer a unique opportunity to examine how reductions in anthropogenic emissions impacted atmospheric aerosol composition in urban environments. This study investigates the day-night variability of size-resolved water-soluble ions in ambient particulate matter (PM) collected in Metro Manila before (November 2019–February 2020) and after (November 2020–February 2021) lockdown implementation. Using tandem Micro-Orifice Uniform Deposit Impactors (MOUDIs), aerosol samples were collected during daytime (06:00–18:00) and nighttime (18:00–06:00) periods and analyzed for key ionic species (sulfate, ammonium, nitrate, oxalate, sodium, chloride, calcium, and magnesium) via ion chromatography. Submicrometer water-soluble mass declined post-lockdown, particularly during daytime, reflecting suppressed secondary formation …


Unraveling Crop Nitrogen-Water Dynamics With Hyperspectral-Thermal Sensing In Northern Central Valley, California, Shahryar Fazli, Surendra Maharjan, Wenzhao Li, Joshua B. Fisher, Rejoice Thomas, Fernando Romero Galvan, Gabriela Shirkey, Hesham El-Askary Sep 2025

Unraveling Crop Nitrogen-Water Dynamics With Hyperspectral-Thermal Sensing In Northern Central Valley, California, Shahryar Fazli, Surendra Maharjan, Wenzhao Li, Joshua B. Fisher, Rejoice Thomas, Fernando Romero Galvan, Gabriela Shirkey, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Ensuring global food security in the face of climate change requires optimizing crop water use and nutrient management. This study investigates the relationship between canopy nitrogen (N) and evapotranspiration (ET) across sunflower, rice, walnut, alfalfa, and plum crops using advanced remote sensing technologies. High-resolution hyperspectral data from NASAs Earth Surface Mineral Dust Source Investigation (EMIT) and thermal multispectral data from the Landsat-based OpenET system were analyzed over 1,135 km2 in California. Regression analysis revealed strong spatial association between canopy N and ET for sunflower (R2 = 0.82), rice (R2 = 0.71), and walnut (R2 = 0.68), …


Milkfish (Chanos Chanos) Bones As A Biosorbent For Mercury (Ii) Contamination In Water, Seth Uriel K. Neri, Ethan Kyle Mangao, Christian Kevin F. Redoblado, Anthony Cesar Y. Ponce, Roby Boy P. Riego, Jupiter O. Yap Aug 2025

Milkfish (Chanos Chanos) Bones As A Biosorbent For Mercury (Ii) Contamination In Water, Seth Uriel K. Neri, Ethan Kyle Mangao, Christian Kevin F. Redoblado, Anthony Cesar Y. Ponce, Roby Boy P. Riego, Jupiter O. Yap

Sinaya: A Philippine Journal for Senior High School Teachers and Students

Heavy metals, such as mercury contamination in water sources are a major environmental and public health issue in many countries. Traditional methods for removing heavy metals from water are effective but often costly and unsustainable and may produce secondary waste. Recent trends favor more sustainable alternatives, such as biosorbents in treating water with heavy metals. Milkfish (Chanos chanos), a common fish in the Philippines, contains hydroxyapatite in the bones that can bind with heavy metals through physical and chemical adsorption mechanisms. This study aims to evaluate the mercury (II) reduction capacity of biosorbent derived from milkfish bones in water, specifically …


New Precipitation Is Scarce In Deep Soils: Findings From 47 Forest Plots Spanning Switzerland, Emily I. Burt, Scott T. Allen, Sabine Braun, Simon Tresch, James W. Kirchner, Gregory R. Goldsmith Aug 2025

New Precipitation Is Scarce In Deep Soils: Findings From 47 Forest Plots Spanning Switzerland, Emily I. Burt, Scott T. Allen, Sabine Braun, Simon Tresch, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As precipitation infiltrates into soils, it can recharge them, displace previously stored waters, or bypass already-filled pores. Using 3,697 δ2H and δ18O measurements of water collected nearly monthly over >3 years in 47 forest plots across Switzerland, we present a systematic investigation of the controls on mobile soil water transport. We quantified the lags and damping of water as it percolates downward using young water fraction analysis (Fyw), and the fractions of soil water composed by precipitation that fell within the previous month (new water fractions, Fnew). The Fnew of water sampled in surface soils ranged …