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Articles 61 - 90 of 780

Full-Text Articles in Physical Sciences and Mathematics

Impacts Of Faculty Development On Interdisciplinary Undergraduate Teaching And Learning In The Food-Energy-Water Nexus, A. Sommers, J. Dauer, H. White, C. Forbes Jan 2022

Impacts Of Faculty Development On Interdisciplinary Undergraduate Teaching And Learning In The Food-Energy-Water Nexus, A. Sommers, J. Dauer, H. White, C. Forbes

School of Natural Resources: Faculty Publications

No abstract provided.


Legacy And Emerging Contaminants In Water And Wastewater, P. Chakraborty, Daniel D. Snow Jan 2022

Legacy And Emerging Contaminants In Water And Wastewater, P. Chakraborty, Daniel D. Snow

School of Natural Resources: Faculty Publications

No abstract provided.


When To Prepare: "Water" You Thinking About Drought?, O. G. Campbell, C. Schwartz, Deborah J. Bathke Jan 2022

When To Prepare: "Water" You Thinking About Drought?, O. G. Campbell, C. Schwartz, Deborah J. Bathke

School of Natural Resources: Faculty Publications

No abstract provided.


Scale-Up Of Flow-Electrode Capacitive Deionization Method For Hard Water Softening, Noah Henry Jan 2022

Scale-Up Of Flow-Electrode Capacitive Deionization Method For Hard Water Softening, Noah Henry

Williams Honors College, Honors Research Projects

This study’s purpose is to further document a capacitive deionization design that could be capable of purifying H2O at a household scale where clean water is otherwise unobtainable in applicable regions of the world. The hypothesis behind this study was continuously larger scaled electrochemical cell-units would increase their water softening capabilities in sustainable fashion. The trend at which performance will scale is currently unknown. The units studied were constructed using graphite plates, anion exchange membranes, cation exchange membranes, and Teflon channels. Three streams, two being CaCl2 solutions in DI H2O (one being concentrated with CaCl …


Phytoplankton Bloom Stages Estimated From Chlorophyll Pigment Proportions Suggest Delayed Summer Production In Low Sea Ice Years In The Northern Bering Sea, Clare B. Gaffey, Karen E. Frey, Lee W. Cooper, Jacqueline M. Grebmeier Jan 2022

Phytoplankton Bloom Stages Estimated From Chlorophyll Pigment Proportions Suggest Delayed Summer Production In Low Sea Ice Years In The Northern Bering Sea, Clare B. Gaffey, Karen E. Frey, Lee W. Cooper, Jacqueline M. Grebmeier

Geography

Decreased sea ice cover in the northern Bering Sea has altered annual phytoplankton phenology owing to an expansion of open water duration and its impact on ocean stratification. Limitations of satellite remote sensing such as the inability to detect bloom activity throughout the water column, under ice, and in cloudy conditions dictate the need for shipboard based measurements to provide more information on bloom dynamics. In this study, we adapted remote sensing land cover classification techniques to provide a new means to determine bloom stage from shipboard samples. Specifically, we used multiyear satellite time series of chlorophyll a to determine …


Drought Tolerant Landscaping Trends In Claremont, California, Serena Myjer Jan 2022

Drought Tolerant Landscaping Trends In Claremont, California, Serena Myjer

CMC Senior Theses

The environmental impacts of turf grass lawns are particularly important to consider in California, because of its unique Mediterranean climate and ongoing problems with chronic drought. While California is ideal for agriculture, recreation, and year-round living, the occurrence of drought is natural and not uncommon, evident in historical human and paleoclimate records. Drought impacts humans and wildlife including water scarcity, crop failure, water quality, reduced streamflow, and wetland availability. Diverting water from these critical sources for growing turf grass lawns is inappropriate and harmful. This project is the first analysis of landscaping patterns, trends, and changes in Claremont, California using …


Present And Future Thermal Regimes Of Intertidal Groundwater Springs In A Threatened Coastal Ecosystem, Jason J. Karrisallen, Aaron A. Mohammed, Joseph Tamborski, Rob C. Jamieson, Serban Danielescu, Barret L. Kurylyk Jan 2022

Present And Future Thermal Regimes Of Intertidal Groundwater Springs In A Threatened Coastal Ecosystem, Jason J. Karrisallen, Aaron A. Mohammed, Joseph Tamborski, Rob C. Jamieson, Serban Danielescu, Barret L. Kurylyk

OES Faculty Publications

In inland settings, groundwater discharge thermally modulates receiving surface water bodies and provides localized thermal refuges; however, the thermal influence of intertidal springs on coastal waters and their thermal sensitivity to climate change are not well studied. We addressed this knowledge gap with a field- and model-based study of a threatened coastal lagoon ecosystem in southeastern Canada. We paired analyses of drone-based thermal imagery with in situ thermal and hydrologic monitoring to estimate discharge to the lagoon from intertidal springs and groundwater-dominated streams in summer 2020. Results, which were generally supported by independent radon-based groundwater discharge estimates, revealed that combined …


Strength In Numbers: Avian Influenza A Virus Transmission To Poultry From A Flocking Passerine, J. Jeffrey Root, Jeremy W. Ellis, Susan A. Shriner Jan 2022

Strength In Numbers: Avian Influenza A Virus Transmission To Poultry From A Flocking Passerine, J. Jeffrey Root, Jeremy W. Ellis, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

The effects of flock size of European starlings (Sturnus vulgaris) was experimentally manipulated to assess the potential of influenza A virus (IAV; H4N6) transmission from a flocking passerine to bobwhite quail (Colinus virginianus) through shared food and water resources to mimic starling intrusions into free-range and backyard poultry operations. Of the three starling flock sizes tested (n = 30, n = 20 and n = 10), all successfully transmitted the virus to all or most of the quail in each animal room (6/6, 6/6 and 5/6) by the end of the experimental period, as determined by seroconversion and/or viral RNAshedding. …


Review Of Analytical Techniques For Arsenic Detection And Determination In Drinking Water, Abhijnan Bhat, Tony O'Hara, Furong Tian, Baljit Singh Dr. Jan 2022

Review Of Analytical Techniques For Arsenic Detection And Determination In Drinking Water, Abhijnan Bhat, Tony O'Hara, Furong Tian, Baljit Singh Dr.

Articles

Arsenic occurs in the natural environment in four oxidation states: As(V), As(III), As(0) and As(−III). The behavior of arsenic species changes depending on the biotic or abiotic conditions in water. In groundwater, arsenic is predominantly present as As(III) and As(V), with a minor amount of methyl and dimethyl arsenic compounds being reported. Global intake of As(III) and As(V) via drinking water and food has dramatically increased in recent years. The commonly used term inorganic arsenic includes both As(III) and As(V) species and constitutes the highest toxicological risk associated with arsenic in water compared to the organic arsenic species. Inorganic arsenic …


Supramolecular Solvent-Based Microextraction For The Preconcentration Of Pb2+ Andcd2+ Prior To Spectrophotometric Detection, Huma Zafar, Faheem Shah, Rafaqat Ali Khan, Asad Muhammad Khan, Jan Nisar, Bushra Ismail Jan 2022

Supramolecular Solvent-Based Microextraction For The Preconcentration Of Pb2+ Andcd2+ Prior To Spectrophotometric Detection, Huma Zafar, Faheem Shah, Rafaqat Ali Khan, Asad Muhammad Khan, Jan Nisar, Bushra Ismail

Turkish Journal of Chemistry

Supramolecular solvent-based dispersive liquid-liquid microextraction technique has been developed as a preconcentration tool for the determination of trace level of Pb2+ and Cd2+. Dodecanol dispersed in tetrahydrofuran has been utilized as a supramolecular-solvent system for the extraction of analytes prior to their quantitative determination with graphite furnace atomic absorption spectrophotometer. Both Pb2+ and Cd2+, which were efficiently extracted by supramolecular solvent system, were complexed with dithizone followed by the addition of supramolecular solvent. The experimental variables that could possibly influence the extraction efficiency, i.e. pH value, temperature, sample volume, centrifugation time, rate of centrifugation, ionic strength, etc. were subjected to …


Schiff Base Functionalized Silica Gel For Simultaneous Separation And Preconcentration Of Cu(Ii), Ni(Ii), And Cd(Ii) In Pharmaceuticals And Water Samples, Feyzullah Tokay, Sema Bağdat Jan 2022

Schiff Base Functionalized Silica Gel For Simultaneous Separation And Preconcentration Of Cu(Ii), Ni(Ii), And Cd(Ii) In Pharmaceuticals And Water Samples, Feyzullah Tokay, Sema Bağdat

Turkish Journal of Chemistry

A method for separation and preconcentration of Cu(II), Ni(II), and Cd(II) using N-N'-bis(5-methoxsalicylidene)-2-hydroxy-1,3-propanediamine modified silica gel was improved for aqueous samples and pharmaceuticals. Determination of the analytes was achieved by inductively coupled plasma optic emission spectrometry. The experimental conditions including pH value, sample volume, eluent type and volume, sorbent mass, sample, and eluent flow rates were optimized with univariate and multivariate optimization tools. The relative standard deviations of the method were 2.9% for Cu(II), 3.0% for Ni(II), and 3.3% for Cd(II) with recovery values between 98.8 ± 3.2-101.5 ± 3.0%. The limits of detection were found to be 62.4, 39.5, …


Salt Marshes As Groundwater Buffers For Development: A Survey Of South Carolina Salt Marsh Basins, Alicia M. Wilson, Meghan Shanahan, Erik M. Smith Dec 2021

Salt Marshes As Groundwater Buffers For Development: A Survey Of South Carolina Salt Marsh Basins, Alicia M. Wilson, Meghan Shanahan, Erik M. Smith

Faculty Publications

Salt marshes serve as zones of intense groundwater mixing and reaction between freshwater uplands and estuaries. This raises the question of whether the impacts of upland development on nutrient and carbon species can be transmitted through salt marshes via groundwater, or whether salt marshes can buffer estuarine waters from coastal development. We sampled groundwater from fifteen tidal creek basins in South Carolina to test for compositional differences associated with development and marsh width. Groundwater samples from near creekbanks and below freshwater uplands were analyzed for salinity, total dissolved nitrogen and phosphorus, and dissolved organic carbon. Analyses revealed significantly higher TDN …


Comprehensive Report On Extraterrestrial Resource Extraction, Robinson Raphael Dec 2021

Comprehensive Report On Extraterrestrial Resource Extraction, Robinson Raphael

Student Works

The prospect of asteroid mining provides a plethora of riches that include metals and water. As the number of discovered asteroids continues to grow, opportunities arise to commercialize these resources within Near-Earth Asteroids (NEAs). With urgent applications on Earth and in space, NEAs allow for a surge in sales. Planning forward, Astroider Aerospace Systems follows a mission split into four phases. Phase 1 develops a series of spacecraft using existing technologies, titled as Near-Earth Asteroid Miners and Near-Earth Asteroid Surveyors. Phase 2 first launches the surveyors to candidate NEAs, prospecting them for ores. To identify potential celestial bodies for this …


California Drought Outlooks Based On Climate Change Models’ Effects On Water Availability, Lauren Lynam, Thomas Piechota Nov 2021

California Drought Outlooks Based On Climate Change Models’ Effects On Water Availability, Lauren Lynam, Thomas Piechota

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Future streamflow in California is evaluated based on eight climate projections models and the effects on water availability. The unimpaired projected streamflow for eleven California rivers, collected from Cal-Adapt, are compared with unimpaired historical flows (1950–2015) using eight climate model projections (2020–2099) identified as representative as possible future scenarios; Warm Dry RCP 4.5, Average RCP 4.5, Cool Wet RCP 4.5, Other RCP 4.5, Warm Dry RCP 8.5, Average RCP 8.5, Cool Wet RCP 8.5, and Other RCP 8.5. Projected drought deficits (or magnitudes), durations, and intensities are statistically tested against historical values to determine significance of differences between past streamflow …


Ultrasound Regulated Flexible Protein Materials: Fabrication, Structure And Physical-Biological Properties., Bowen Cai, Hanling Gu, Fang Wang, Kyle Printon, Zhenggui Gu, Xiao Hu Nov 2021

Ultrasound Regulated Flexible Protein Materials: Fabrication, Structure And Physical-Biological Properties., Bowen Cai, Hanling Gu, Fang Wang, Kyle Printon, Zhenggui Gu, Xiao Hu

College of Science & Mathematics Departmental Research

Ultrasound can be used in the biomaterial field due to its high efficiency, easy operation, no chemical treatment, repeatability and high level of control. In this work, we demonstrated that ultrasound is able to quickly regulate protein structure at the solution assembly stage to obtain the designed properties of protein-based materials. Silk fibroin proteins dissolved in a formic acid-CaCl solution system were treated in an ultrasound with varying times and powers. By altering these variables, the silks physical properties and structures can be fine-tuned and the results were investigated with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron …


Physical And Chemical Properties Of Soil, Water And Air Around Ukawu Pb-Zn Mine, Southeastern Nigeria, Nwachukwu Arthur Nwachukwu, Sikakwe Gregory Udie, Eluwa Ndidiamaka Nchedo, Uwa Clementina Ukamaka, Oluwatoyin Oluwatosin Olaosebikan Jun 2021

Physical And Chemical Properties Of Soil, Water And Air Around Ukawu Pb-Zn Mine, Southeastern Nigeria, Nwachukwu Arthur Nwachukwu, Sikakwe Gregory Udie, Eluwa Ndidiamaka Nchedo, Uwa Clementina Ukamaka, Oluwatoyin Oluwatosin Olaosebikan

Makara Journal of Science

In this study, analysis of water, and soil samples, air quality, and noise levels in Ukawu Pb-Zn mine were examined. The pH of the water samples, at 6.7, exceeded permissible levels for potable water established by the National Environmental Standard Regulatory Agency (NESREA), European Union, and World Health Organization (i.e., 7.0-8.5). The soil pH was 5.2, which indicates acidity due to acid mine drainage. Low soil pH is evidence of acid mine drainage. All cations detected in water and soil were below standard limits considered harmful by the NESREA. Measurements of precursor gases, such as O3, NO2 …


A Theoretical Study Of Synchronous Proton Transfer In (Hf)N, (H2O) N, And (Hcl) N Where N = 3, 4, 5, Johnny Yang May 2021

A Theoretical Study Of Synchronous Proton Transfer In (Hf)N, (H2O) N, And (Hcl) N Where N = 3, 4, 5, Johnny Yang

Honors Theses

For (HF)n, (H2O)n, and (HCl)n (n = 3 − 5), we have rigorously characterized the structures for the minima and transition states for synchronous proton transfer (SPT) with the CCSD(T) method and aug-cc-pVTZ basis set. The electronic barrier heights (∆E) associated with these transition states have also been computed with the explicitly correlated CCSD(T)-F12 method and the aug-cc-pVQZ-F12 basis set (abbreviated aQZ-F12). (HCl)n (n = 3 − 5) SPT transition states have not been previously identified to the best of our knowledge, and they have been found …


Terra Dispositions: A Lithospheric Investigation Of Wet-Matter, Alec Rovensky May 2021

Terra Dispositions: A Lithospheric Investigation Of Wet-Matter, Alec Rovensky

Architecture Senior Theses

Human intervention of the landscape by damming, filling wetlands and over-extracting is resulting in the rapid perversion of water bodies through the desertification or flooding of terrain and the ensuing contamination of reservoirs. In turn, these changes are disrupting ecosystems, reshaping geological borders, and causing irreversible damage that poses a threat to clean water supplies. As humans exert agency over local hydrology, there is scarce consideration of the ensuing ecological consequences. This thesis aims to expose the ecological transformations of territories laced with human agency by examining the residues left by water in order to deviate from the misplaced nostalgia …


Informing Drought Mitigation Policy By Estimating The Value Of Water For Crop Production, Renata Rimsaite, Justin Gibson, Nicholas Brozovic Apr 2021

Informing Drought Mitigation Policy By Estimating The Value Of Water For Crop Production, Renata Rimsaite, Justin Gibson, Nicholas Brozovic

School of Natural Resources: Faculty Publications

Farmers use irrigation to mitigate drought risk and reduce yield uncertainty. A clear understanding of the monetary value of irrigation water and how it varies across time and space can help to inform farmers and policymakers about the potential impacts of water shortages and reduce uncertainty in decision making. Here, we introduce a framework for understanding the economic value of water used to produce corn in the central High Plains region during the period 2010–2017. Our analysis uses publicly available data for corn price and for irrigated and non-irrigated yields and incorporates irrigation requirement adjustments to account for the hydrologic …


Can CP Be Less Than CV?, Yingbin Ge, Samuel L. Montgomery, Gabriel L. Borrello Apr 2021

Can CP Be Less Than CV?, Yingbin Ge, Samuel L. Montgomery, Gabriel L. Borrello

All Faculty Scholarship for the College of the Sciences

Can CP be less than CV? This is a fundamental question in physics, chemistry, chemical engineering, and mechanical engineering. This question hangs in the minds of many students, instructors, and researchers. The first instinct is to answer “Yes, for water between 0 and 4 °C” if one knows that water expands as temperature decreases in this temperature range. The same question is asked in several Physical Chemistry and Physics textbooks. Students are supposed to answer that water contracts when heated at below 4 °C in an isobaric process. Because work is done to the contracting water, less …


Fate Of Persistent Contaminants And Emerging Algal Toxins In Drinking Water And The Environment, Danielle Christine Westerman Apr 2021

Fate Of Persistent Contaminants And Emerging Algal Toxins In Drinking Water And The Environment, Danielle Christine Westerman

Theses and Dissertations

Population growth and global climate change has resulted in the degradation of pristine water sources, causing issues like saltwater intrusion, persistent harmful algal blooms, and drought from population growth. Future reliance on alternative sources of drinking water to is expected globally, therefore, nontraditional sources of drinking water are becoming increasingly vital sources of potable water around the world. For example, desalination (typically by reverse osmosis), despite its high energy demands and high cost, is being utilized all over the world to meet drinking water demand. Wastewater reuse, the additional treatment of wastewater to produce drinking water, either directly or indirectly, …


Carbonatite Metasomatism And Water Systematics Of Peridotite Xenoliths From Lanzarote, Canaries, Sierra N. Patterson Apr 2021

Carbonatite Metasomatism And Water Systematics Of Peridotite Xenoliths From Lanzarote, Canaries, Sierra N. Patterson

Theses and Dissertations

Water in Earth’s mantle, present as structurally bound hydrogen in minerals, influences large scale processes like mantle deformation, plate tectonics, and melting. To better understand the processes controlling water concentrations in the Earth’s upper mantle, we analyzed hydrogen (calculated as ppm wt. H2O), major, and trace element concentrations in minerals from peridotite mantle xenoliths of Lanzarote, Canaries. The Canaries Islands are thought to be the surface expression of a deep-seated mantle plume erupting through the Atlantic Ocean lithosphere. Carbonatite magmas have erupted in the Canaries and previous studies have shown evidence for carbonatite metasomatism in Lanzarote peridotites. Thus, …


How And Why Mars Lost Its Water, Sana Akhter, Andre Beikircher Feb 2021

How And Why Mars Lost Its Water, Sana Akhter, Andre Beikircher

2021 Honors Council of the Illinois Region

The topic of this paper is to investigate how and why Mars lost its water. It is important to study the loss of water on Mars because it can give us a better understanding of how Mars once looked, if life were possible, and how it could have changed so drastically to what it is now. The paper aims to address which factors led to Mars losing its water and how long ago this happened. Using our data, we will predict how quickly Mars’ core cooled, when its magnetic field weakened, and when the water was lost. We learned that …


Analysis Of Water Concentration Formed Within Deformed Synthetic Quartz Crystals, Andrew Steward Jan 2021

Analysis Of Water Concentration Formed Within Deformed Synthetic Quartz Crystals, Andrew Steward

Williams Honors College, Honors Research Projects

Analyzing the strength of synthetic quartz is essential to understanding the strength of natural milky quartz, which likely controls the strength of Earth’s continental crust. Synthetic quartz is sometimes used for deformation experiments because it has a homogenous water distribution unlike natural milky quartz. The purpose of this study is to determine if annealing synthetic quartz at T = 600°C will convert the water in synthetic quartz to free water, like milky quartz, but with little water loss. Following two annealing experiments at Texas A&M University, I performed four annealing experiments to measure the water content of five synthetic quartz …


Water Pollution And Environmental Concerns In Anesthesiology, Marc Kostrubiak, Christine Vatovec, Lesley-Ann Dupigny-Giroux, Donna Rizzo, William Paganelli, Mitchell Tsai Jan 2021

Water Pollution And Environmental Concerns In Anesthesiology, Marc Kostrubiak, Christine Vatovec, Lesley-Ann Dupigny-Giroux, Donna Rizzo, William Paganelli, Mitchell Tsai

Larner College of Medicine Fourth Year Advanced Integration Teaching/Scholarly Projects

Medications administered by anesthesia health care providers and subsequently excreted into the water supply system have the potential to affect ecological systems. Presently, there is a lack of literature examining which medications or metabolites enter the waste stream. Further, assessments of their potential environmental impact are often unknown or simply not considered as an externality of medical practice. Recent work examining the practice of anesthesiology has explored the solid waste stream, and the global warming potential of anesthetic gases, however the potential aquatic impacts remain unexplored. To address the potential for waterborne pollution and environmental toxicity, we extracted the total …


Hydrologic Investigation Of The Chiwaukee Prairie (Wisconsin) Restoration, Nick Potter Jan 2021

Hydrologic Investigation Of The Chiwaukee Prairie (Wisconsin) Restoration, Nick Potter

Dissertations, Master's Theses and Master's Reports

Wetlands are a vital component of the landscape, a keystone ecosystem, that are prone to degradation and destruction with urbanization. As a result, significant efforts from communities, scientists, sportsmen and government agencies have been made to protect and restore wetlands. In 2019, The Nature Conservancy began re-wetting, contouring, and seeding a 55-ha parcel of farmland in Pleasant Prairie, Wisconsin, restoring the site in an attempt to resemble pre-settlement conditions. The Nature Conservancy Restoration site is part of the groundwater recharge zone of Chiwaukee Prairie and its restoration aimed to increase the available groundwater for adjacent Chiwaukee Prairie State Natural Area …


Spatiotemporal Patterns In Water Yield From The Humid Puna: A Case Study In The Agrarian District Of Zurite, Perú, Wyeth Wunderlich Jan 2021

Spatiotemporal Patterns In Water Yield From The Humid Puna: A Case Study In The Agrarian District Of Zurite, Perú, Wyeth Wunderlich

Cal Poly Humboldt theses and projects

The humid puna is a seasonally dry alpine grass- and shrub-land biome that exists at the altitudinal limits of plant survival, hosts peat-forming wetlands known as bofedales, and yields water to streams used by small and large communities throughout the central and southern Peruvian Andes. Despite the importance of the humid puna in supplying water resources, particularly to perennial streams, few studies have quantified water yield and no studies have explored relationships between the structure of puna landscapes and spatial patterns in water yield. Zurite (population: 3,640, elevation: 3,011 m.a.s.l., annual precipitation: 855 mm) is an agrarian district in …


Aggregation And Degradation Of Dispersants And Oil By Microbial Exopolymers (Addomex): Toward A Synthesis Of Processes And Pathways Of Marine Oil Snow Formation In Determining The Fate Of Hydrocarbons, Antonietta Quigg, Peter H. Santschi, Chen Xu, Kai Ziervogel, Manoj Kamalanathan, Wei-Chun Chin, Adrian B. Burd, Andrew Wozniak, Patrick G. Hatcher Jan 2021

Aggregation And Degradation Of Dispersants And Oil By Microbial Exopolymers (Addomex): Toward A Synthesis Of Processes And Pathways Of Marine Oil Snow Formation In Determining The Fate Of Hydrocarbons, Antonietta Quigg, Peter H. Santschi, Chen Xu, Kai Ziervogel, Manoj Kamalanathan, Wei-Chun Chin, Adrian B. Burd, Andrew Wozniak, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Microbes (bacteria, phytoplankton) in the ocean are responsible for the copious production of exopolymeric substances (EPS) that include transparent exopolymeric particles. These materials act as a matrix to form marine snow. After the Deepwater Horizon oil spill, marine oil snow (MOS) formed in massive quantities and influenced the fate and transport of oil in the ocean. The processes and pathways of MOS formation require further elucidation to be better understood, in particular we need to better understand how dispersants affect aggregation and degradation of oil. Toward that end, recent work has characterized EPS as a function of microbial community and …


Stable Isotope Composition Of Surface Water Across Central Mexico, Jordan Foote Dec 2020

Stable Isotope Composition Of Surface Water Across Central Mexico, Jordan Foote

Earth & Environmental Sciences Theses

Understanding the controlling factors of modern surface water stable isotope compositions is important for reconstructions of paleoclimate and paleoelevation. Few studies have attempted to understand patterns of surface water isotope compositions and their controlling factors in Mexico. Here I study the δ18O, δD and d-excess values of 124 modern river, lake and spring water samples across the Sierra Madre Occidental, Central Mexican Plateau and Sierra Madre Oriental to constrain the spatial pattern and lapse rate. These samples were collected at various elevations after the wet season in 2019. The isotope data were integrated with moisture back trajectory analysis and climatic …


Impact Of Interlayer Cation Composition And Strongly Bound Water On Smectite ẟ²H, As Determined By A Modified Tcea Method, Nadine J. Kanik Nov 2020

Impact Of Interlayer Cation Composition And Strongly Bound Water On Smectite ẟ²H, As Determined By A Modified Tcea Method, Nadine J. Kanik

Electronic Thesis and Dissertation Repository

Interlayer cation composition and cation hydration enthalpy can potentially affect the excess hydrogen-yield and δ2H of smectitic clays. Complexities arise from condensed atmospheric water adsorbed on the clay, as it constitutes a potential additional source of hydrogen when attempting to measure the δ2H of structural OH groups. To approach this problem, the δ2H of different cation-saturated, dried forms of six Clay Minerals Society Source Clay smectites were measured. A modified sample drying and on-line High-Temperature-Conversion-Elemental-Analysis (TCEA) Continuous-Flow-Isotope-Ratio-Mass-Spectrometry protocol, facilitated isotopic measurements. A stronger interlayer cation hydration enthalpy (Ca2+>Na+>K+), …