Environmental Chemistry Commons^™

Understanding Biogeochemical And Physical Controls On Methane Air-Sea Exchange Fluxes In The Pacific Ocean, Sarah Raney

Master's Theses

Methane and trace element samples were collected on GEOTRACES GP15 Pacific Meridional Transect (PMT) cruise conducted between the Aleutian Islands (57 °N) and Tahiti (20 °S) from September to November 2018. Uncertainty in methane air-sea exchange fluxes was determined using a propagation of errors approach. Fluxes ranged from -0.88 to 4.9 µmol CH₄ m^-2 d^-1. Average CH₄ flux along the Alaskan margin was 2.2 ± 2.9 µmol CH₄ m^-2 d^-1. Methane fluxes decreased moving southward and increased to their open ocean maximum around 20 °N before declining in equatorial waters. Near …

The Design Of A Efficient Production And Purification Of Fibroblast Growth Factor 2, Mandeep Kaur

Chemistry & Biochemistry Undergraduate Honors Theses

Chronic wounds pose a major problem in the United States with an estimate of twenty-five million dollars a year spent on associated treatments. Growth factors can be used as a potential treatment for chronic wounds since they promote cell proliferation and angiogenesis. This study employs one specific growth factor, fibroblast growth factor 2 (FGF2) so that it could potentially be used in future treatment. Wild-type FGF2 is thermally unstable, and it has a mean elimination time of 7.6 hours. This study attempted to improve upon its stability through a mutation on the heparin binding loop. The mutation performed was K134E. …

Evaluating Alternative Ebullition Models For Predicting Peatland Methane Emission And Its Pathways Via Data–Model Fusion, Shuang Ma, Lifen Jiang, Rachel M. Wilson, Jeff P. Chanton, Scott Bridgham, Shuli Niu, Colleen M. Iversen, Avni Malhotra, Jiang Jiang, Xingjie Lu, Yuanyuan Huang, Jason Keller, Xiaofeng Xu, Daniel M. Ricciuto, Paul J. Hanson, Yiqi Luo

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding the dynamics of peatland methane (CH4) emissions and quantifying sources of uncertainty in estimating peatland CH4 emissions are critical for mitigating climate change. The relative contributions of CH4 emission pathways through ebullition, plant-mediated transport, and diffusion, together with their different transport rates and vulnerability to oxidation, determine the quantity of CH4 to be oxidized before leaving the soil. Notwithstanding their importance, the relative contributions of the emission pathways are highly uncertain. In particular, the ebullition process is more uncertain and can lead to large uncertainties in modeled CH4 emissions. To improve model simulations of CH4 emission and its pathways, …

The Phosphorus Problem In The Pre-Biotic World, Erica Bronwyn Mobley

ONU Student Research Colloquium

The so-called “phosphorus problem” in prebiotic life has traditionally been framed in terms of phosphate solubility. Phosphates (PO₄^3-) are generally insoluble and therefore cannot supply adequate nutrients for protocellular metabolism. Phosphite (HPO₃^2-) is thought to solve this problem, but introduces a new obstacle, what might be termed the “phosphorus permeability problem”. Phosphate and phosphite are both charged at circumneutral pH and cannot cross a lipid membrane. No evolutionary pressure exists to drive formation of transporters prior to the existence of a membrane, and so the first protocells likely lacked transporters. We suggest that volatile …

Evaluating The Impact Of River Settlement On Phosphorus Uptake, Erica Bronwyn Mobley

ONU Student Research Colloquium

Phosphorus sorption to sediments is an important process that can buffer dissolved P concentrations. Both the amount of P and sediment as well as the mode of binding can influence transport of P in aquatic ecosystems. This study focused on determining sediment stocks in the Maumee River basin and quantifying reactive and total P extracted from sediment by a sequential multi-step process. Quantification of sediment stock will enable more accurate modeling of P retention and ultimately P loading into western Lake Erie.

Synthesis And Characterization Of A Novel Reaction-Based Azaborine Fluorescent Probe Capable Of Selectively Detect Carbon Monoxide Based On Palladium-Mediated Carbonylation Chemistry, Samuel Moore, Carl Jacky Saint-Louis

Symposium of Student Scholars

Azaborines are fascinating compounds because they possess valuable properties such as photochemical stability, have high molar absorption coefficient and high fluorescent quantum yields, as well as large Stokes shifts and tunable absorption/emission spectra. Here, we designed, synthesized, and will examine a novel reaction-based azaborine fluorescent probe capable of selectively detect carbon monoxide (CO) based on palladium-mediated carbonylation chemistry. This novel azaborine fluorescent probe will exhibit high selectivity for CO and display a robust turn-on fluorescent response in the presence of CO in aqueous buffer solution.

Corrosion Prevention Of Aluminum Alloy, Andrea Brenner

Symposium of Student Scholars

Aluminum alloy (Al-alloy) is a widely used metal in construction, aerospace, aviation, and other necessary fields due to its lightweight and tweakable properties. However, corrosion is inevitable on metals and alloys, and that causes millions of dollars of revenue loss every year. Therefore, we propose to research fabricating coating to prevent corrosion on Al-alloy. This study uses an iron-based metal-organic framework (MOF) and polyurethane (PU) based composite coating to prevent corrosion on the Al-alloy. The makeup of the composite material is changed by varying the percentage of MOF. In addition, a binder is also used to enhance the homogenization between …

Limits Of Detection Of Mycotoxins By Laminar Flow Strips: A Review, Xinyi Zhao, Hugh Byrne, Christine M. O’Connor, James Curtin, Furong Tian

Articles

Mycotoxins are secondary metabolic products of fungi. They are poisonous, carcinogenic, and mutagenic in nature and pose a serious health threat to both humans and animals, causing severe illnesses and even death. Rapid, simple and low-cost methods of detection of mycotoxins are of immense importance and in great demand in the food and beverage industry, as well as in agriculture and environmental monitoring, and, for this purpose, lateral flow immunochromatographic strips (ICSTs) have been widely used in food safety and environmental monitoring. The literature to date describing the development of ICSTs for the detection of different types of mycotoxins using …

Temporal Changes And Possible Sources Of Dissolved Calcium Levels In Stream, River, And Lake Waters In Western Kentucky, Kelsie Meystedt

Scholars Week

ABSTRACT

Zebra Mussels (Dreissena polymorpha) are an exotic and invasive mollusk that spread extensively over various rivers and lakes in the United States. These mussels are known for being notorious in their “biofouling” capabilities, costing the U.S. government billions of dollars in removal operations. Recently, zebra mussel colonies were found in Kentucky Lake possibly due to human activities increasing the salinity of today’s freshwater resources. The increase in salinity from human activities may have adversely affected the ecosystems and water supplies. The Specific aim of this study was to determine the temporal trend of dissolved calcium in Kentucky Lake …

Competitive Sorption And Transport Of Heavy Metals In Soil And Mn Oxide-Coated Sand, Joshua Tyler Padilla

LSU Doctoral Dissertations

This study investigated the competitive sorption of Ni, Pb, and Zn as well as synergistic interactions between Ni and phosphate (P) in soils and Mn oxide-coated sand. During stirred-flow experiments, the sorption of heavy metal cations by Olivier soil was mutually reduced when applied simultaneously. When applied consecutively, the cation of higher affinity was able to displace the cation of lower affinity from the soil surface, however, no evidence for the reverse case was observed. A novel general exchange kinetics model was able to correctly describe such displacement. Competition between Ni and Zn mutually increased mobility in Olivier and Windsor …

The Analysis Of Microplastics Found In The Flowers Of Rhode Island, Hailey Hendricks, Matthew Kiesewetter

Senior Honors Projects

No abstract provided.

Odu’S Peter Bernath Participates In Study That Reveals Damage To Ozone Layer From Extreme Wildfires, Tiffany Whitfield

News Items

No abstract provided.

Arsenic In Groundwater Sources From Selected Communities Surrounding Taal Volcano, Philippines: An Exploratory Study, Geminn Louis C. Apostol, Sary Valenzuela, Xerxes Seposo

Ateneo School of Medicine and Public Health Publications

Arsenic (As) is a highly toxic, carcinogenic trace metal that can potentially contaminate groundwater sources in volcanic regions. This study provides the first comparative documentation of As concentrations in groundwater in a volcano-sedimentary region in the Philippines. Matched, repeated As measurements and physico-chemical analyses were performed in 26 individual wells from 11 municipalities and city in Batangas province from July 2020 to November 2021. Using the electrothermal atomic absorption spectrometric method, analysis of the wells revealed that in 2020, 23 out of 26 (88.46%) had As levels above the WHO limit of >10 ppb while 20 out of 26 wells …

Reno, Carson City And Las Vegas - 1994, University Of Denver

United States Data - Nevada

Relevant Publications

Science Total Environment Publication

Utah Wintertime Measurements Of Heavy-Duty Vehicle Nitrogen Oxide Emission Factors, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald, Adam M. Boies

Fuel Efficiency Automobile Test Publications

There have only been a few wintertime studies of heavy-duty vehicle (HDV) NO_x emissions in the U.S., and while they have observed increased emissions, fleet characterization to identify the cause has been lacking. We have collected wintertime measurements of NO_x emission factors from 1,591 HDV at a Utah Port of Entry in December 2020 that includes individual vehicle identification. In general, the NO_x emission factors for 2011 & newer chassis model year HDV are significantly higher than 2017 spring measurements from California. The newest chassis model year HDV (2017 - 2021) NO_x emission factors are similar …

Methanol Decomposition On Ni(111) And O/Ni(111), Henrik Öström, Bingjie Zhang, Tiffany Vallejo, Bryn Merrill, Jeremy Huang, Jerry Larue

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Methanol decomposition on Ni(111) surfaces has been studied in the presence and absence of oxygen using temperature-programmed desorption and temperature-dependent sum frequency generation spectroscopy. Under both conditions the C–H and O–H bonds break, forming carbon monoxide and atomic hydrogen on the surface. No C–O bond scission was observed, limiting the number of reaction pathways. The O–H bonds break first (>150 K), forming surface methoxy, followed by C–H bond breakage (>250 K). All atomic hydrogen desorbs from the surface as H2 through H+H recombinative desorption. H2 desorbs at a higher temperature in the presence of oxygen (>300 K) …

Wastewater-Based Estimation Of Substances Discharged At The Rest Areas Along The State Highways In Kentucky, Katherine E. Gray, Eugene Shin, Tyler Whitt, Andrew Windhorst, Houston Hampton, Chris Delcher, Bikram Subedi

Posters-at-the-Capitol

The availability of licit and illicit stimulants and its adverse consequences on public health has emerged as a major drug threat to communities in the United States. Despite several drug-involved traffic incidents along the interstate highways, this report represents the first comprehensive and quantitative report of drugs discharged at the rest areas along the interstate highways. In this National Institute of Justice-funded study, the amount of several discharged drugs focusing on stimulants but also including opioids and prescription antipsychotics are being measured in raw wastewater collected from five rest areas and a truck servicing facility using a state-of-the-art mass …

Measurements Of Atmospheric Radicals, Heather L. Runberg

Electronic Theses and Dissertations

Atmospheric particulate matter (PM) is a global health concern. PM_2.5 is formed primarily through combustion processes such as automobile use and industrial activity. Natural sources of PM_2.5 result from events like volcanos and wildfires. Upon inhalation, PM_2.5 is small enough to travel deep into the lungs where it can form reactive oxygen species (ROS), such as hydroxyl radical (OH), causing oxidative damage to pulmonary tissues. PM_2.5 has been linked to cardiopulmonary diseases such as asthma, chronic obstructive pulmonary disease (COPD), and high blood pressure.

PM_2.5 is small enough to remain aloft and travel many hundreds …

Soil Project, Gabriella Hopkins

Natural Sciences Student Research Presentations

What are soil-borne diseases?

- Soil-borne diseases are diseases that can infect plants, animals, and human via soil.

- There are multiple different pathogens that contaminate soil and cause disease including bacteria, fungi, and helminths (parasitic worms). Most of these lay dormant (inactive) in the soil until they come in contact with a host.

- A host such as an animal can become infected by inhaling dormant spores or eggs in the case of helminths or by the pathogen coming in contact with an open wound. These situations are also the case for humans, but humans can also become infected …

Soil Health And The Effects Of Nanoparticles, Elijah Mock

Natural Sciences Student Research Presentations

I researched the effects of soil on human health. Specifically, I was interested in nanoparticles that reside in soil and how they affect humans as well as crops that are planted in the soil. This topic is relevant because nanoparticles can be used to deliver drugs for doctors, create specific properties for material scientists, sensors for the military, and in a plethora of other fields (“What Are Nanoparticles? Definition, Size, Uses and Properties.”).