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Articles 241 - 270 of 317

Full-Text Articles in Environmental Chemistry

Climate Change From Oxygen Isotopic Variation Of Pore Water From Sediments In Punderson Lake, Northeast Ohio, Rachel Daley, Fasong Yuan Sep 2013

Climate Change From Oxygen Isotopic Variation Of Pore Water From Sediments In Punderson Lake, Northeast Ohio, Rachel Daley, Fasong Yuan

Undergraduate Research Posters 2013

The environment in Ohio has changed over time. The hydroclimate, which is the climate of the water, shows changes from the Industrial Revolution to the present. Evidence for these changes can be found in levels of δ18O and δ2H isotopes in the layers of sediment and water in the lakes of Northeast Ohio. Mass spectrometry can be used to test the levels of δ18O and δ2H isotopes from pore water samples within sediment cores. In this study, surface soil and water samples were collected from cores in Punderson Lake at Punderson State Park in Newbury, Ohio. Pore water was extracted …


Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo May 2013

Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo

Senior Honors Projects

Hexachlorocyclohexanes (HCHs) are a family of chlorinated organic compounds that were previously used as agricultural insecticides. HCHs are recognized as persistent organic pollutants due to their toxicity, recalcitrant properties, and tendency to bioaccumulate in food webs. Although HCH was first synthesized in 1825, its use was not widespread until the discovery of the insecticidal activity of the γ-HCH isomer in 1942. γ-HCH and its toxic waste isomers α-HCH and β-HCH were banned from production and use by the United Nations in 2009, yet these chemicals still present environmental problems due to their persistence in soils and surface waters. HCHs continue …


Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan Jan 2013

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR Program Research Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on …


Insights Into Forest Soil Carbon Dynamics From Nuclear Magnetic Resonance Spectroscopy, Chris E. Johnson Jan 2013

Insights Into Forest Soil Carbon Dynamics From Nuclear Magnetic Resonance Spectroscopy, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.


Transformations, Bioavailability And Toxicity Of Manufactured Zno Nanomaterials In Wastewter, Sewwandi Rathnayake Jan 2013

Transformations, Bioavailability And Toxicity Of Manufactured Zno Nanomaterials In Wastewter, Sewwandi Rathnayake

Theses and Dissertations--Plant and Soil Sciences

In order to properly evaluate the ecological and human health risks of ZnO Manufactured nanomaterials (MNMs) released to the environment, it is critical to understand the likely transformation products in the wastewater treatment process and in soils receiving biosolids. To address this critical knowledge gap, we examined the transformation reactions of 30 nm ZnO MNMs in single component and multi-component systems, with phosphate and natural organic matter (NOM). We also assessed the influence of nano ZnO transformation on the bioavailability, and toxicity of ZnO transformation products to Triticum aestivum. The data revealed that ZnO MNMs react with phosphate at …


Recovery Of Sensitive Watersheds In The Northeastern United States From Chronic Acidification: The Role Of Soil Chemistry, Chris E. Johnson Jul 2012

Recovery Of Sensitive Watersheds In The Northeastern United States From Chronic Acidification: The Role Of Soil Chemistry, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.


Analysis Of Biodiesel Quality Using Reversed Phase High-Performance Liquid Chromatography, Kellyann M. Murphy May 2012

Analysis Of Biodiesel Quality Using Reversed Phase High-Performance Liquid Chromatography, Kellyann M. Murphy

Pomona Senior Theses

The alternative fuel biodiesel is produced from the transesterification of vegetable oils or animal fat to fatty acid methyl esters. Pomona has a reactor on campus that can be used to run this reaction and produce biodiesel. The use of biodiesel has been found to lower air pollutant and greenhouse gas emissions, but can be potentially harmful to the engines if it contains impurities. This paper proposes a method using high-performance liquid chromatography to test the quality of biodiesel. This method utilizes instrumentation and materials that are available in Pomona College's Chemistry Department, requires very little sample preparation, and is …


Arsenic Contamination In Groundwater In Vietnam: An Overview And Analysis Of The Historical, Cultural, Economic, And Political Parameters In The Success Of Various Mitigation Options, Thuy M. Ly May 2012

Arsenic Contamination In Groundwater In Vietnam: An Overview And Analysis Of The Historical, Cultural, Economic, And Political Parameters In The Success Of Various Mitigation Options, Thuy M. Ly

Pomona Senior Theses

Although arsenic is naturally present in the environment, 99% of human exposure to arsenic is through ingestion. Throughout history, arsenic is known as “the king of poisons”; it is mutagenic, carcinogenic, and teratogenic. Even in smaller concentrations, it accumulates in the body and takes decades before any physical symptoms of arsenic poisoning shows. According to the World Health Organization (WHO), the safe concentration of arsenic in drinking water is 10 µg/L. However, this limit is often times ignored until it is decades too late and people begin showing symptoms of having been poisoned.

This is the current situation for Vietnam, …


Acetylcholine Esterase Activity And Muscle Contraction In The Sea Urchin Lytechinus Variegatus (Lamarck) Following Chronic Phosphate Exposure, S. Anne Boettger, James B. Mcclintock Jan 2012

Acetylcholine Esterase Activity And Muscle Contraction In The Sea Urchin Lytechinus Variegatus (Lamarck) Following Chronic Phosphate Exposure, S. Anne Boettger, James B. Mcclintock

Biology Faculty Publications

No abstract provided.


Do Wind Turbines Affect Weather Conditions?: A Case Study In Indiana, Meghan F. Henschen, Brittany Herrholtz, Lacey Rhudy, Kathryn Demchak, Brian Doogs, Joshua Holland, Erik Larson, Johnny Martin, Matthew Rudkin Jul 2011

Do Wind Turbines Affect Weather Conditions?: A Case Study In Indiana, Meghan F. Henschen, Brittany Herrholtz, Lacey Rhudy, Kathryn Demchak, Brian Doogs, Joshua Holland, Erik Larson, Johnny Martin, Matthew Rudkin

The Journal of Purdue Undergraduate Research

Wind turbines are becoming increasingly widespread in the United States as the world looks for cleaner sources of energy. Scientists, policymakers, and citizens have strong opinions regarding the positive and negative effects of wind energy projects, and there is a great deal of misinformation about wind energy circulating on the Web and other media sources. The purpose of this study is to gain a better understanding of how the rotation of hundreds of turbines can influence local weather conditions within a wind farm and in the surrounding areas. This experiment measures temperature, atmospheric pressure, wind speed, wind direction, relative humidity, …


An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede May 2011

An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede

Department of Environmental Studies: Undergraduate Student Theses

Stable-hydrogen isotopes are becoming an increasingly popular method of studying migratory birds, though sample preparation methods may affect results.  In this study I examined feathers from red-tailed hawks (Buteo jamaicensis) to determine the relationship between measure of δD due to inter-feather variation or drying methods, assessed the accuracy of results by using two birds of known-origin and estimated possible natal origins of migratory red-tailed hawks.  Two feathers per individual were taken from 81 wild hawks caught at Hitchcock Nature Center near Crescent IA and from 2 rescued red-tailed hawks, Raptor Recovery Nebraska near Eagle, NE. 119 of the …


Reduced Activity Of Multiple Endocrine Disrupting Compounds: 17Β-Estradiol And Bisphenol A With A Chemi-Luminescent Assay, Anna C. Ortiz^, Roberto J. De La Torre-Roche, Marc B. Cox, Wen-Yee Lee* Mar 2011

Reduced Activity Of Multiple Endocrine Disrupting Compounds: 17Β-Estradiol And Bisphenol A With A Chemi-Luminescent Assay, Anna C. Ortiz^, Roberto J. De La Torre-Roche, Marc B. Cox, Wen-Yee Lee*

COURI Symposium Abstracts, Spring 2011

The concern about the impacts of endocrine disrupting compounds (EDCs) in the environment has increased recently with their high occurrence in surface waters and sex changes in various aquatic organisms. EDCs include ubiquitously used pharmaceuticals and personal care products, such as soap, detergents, contraceptives, and other medicines, which are released constantly into the environment, in waste water treatment plant effluent. Though toxicological effects of these individual, EDCs have been studied, knowledge on how these chemicals interact together in the environment is very limited. The objective of this project is to study the multi-residue effect of EDCs using a chemi-luminescent yeast …


Development Of Biomarkers For Endocrine Disrupting Compounds In The Fathead Minnow, Pimephales Promelas, Tara Frare Jan 2011

Development Of Biomarkers For Endocrine Disrupting Compounds In The Fathead Minnow, Pimephales Promelas, Tara Frare

Undergraduate Review

Organic waste compounds (OWC’s) are an environmental concern that can have adverse effects on humans, animals, and the environment. Ethinyl estradiol (EE2) is one common OWC and is an active ingredient in oral birth control pills. The presence of EE2 in aquatic environments and drinking water can be linked to decreased fertility and altered physiology in fish. I am developing Q-PCR biomarkers to detect changes in fish at low concentrations before adverse effects occur at higher concentrations. RNA was extracted from twenty fathead minnows that had not been exposed to OWC’s and will be used to synthesize cDNA. Thus far …


Synthesis, Kinetic And Photocatalytic Studies Of Porphyrin-Ruthenium-Oxo Complexes, Yan Huang Aug 2010

Synthesis, Kinetic And Photocatalytic Studies Of Porphyrin-Ruthenium-Oxo Complexes, Yan Huang

Masters Theses & Specialist Projects

Macrocyclic ligand-complexed transition metal-oxo intermediates are the active oxidizing species in a variety of important biological and catalytic oxidation reactions. Many transition metal catalysts have been designed to mimic the predominant oxidation catalysts in Nature, namely the cytochrome P450 enzymes. Ruthenium porphyrin complexes have been the center of the research and have successfully been utilized, as catalysts, in major oxidation reactions such as the hydroxylation of alkanes. This study focuses on kinetic and photocatalytic studies of oxidation reactions with wellcharacterized high-valent ruthenium-oxo porphyrin complexes.
The trans-dioxoruthenium(VI) porphyrins have been among the best characterized metal-oxo intermediates and their involvement as …


Adaptivearc And The Future Of The Energy Industry, Trevor Chase Apr 2010

Adaptivearc And The Future Of The Energy Industry, Trevor Chase

Earth and Soil Sciences

No abstract provided.


Relatin Dissolved Oxygen Concentration To Fish Distribution In Jarecki Lake, Adam Sutton Apr 2010

Relatin Dissolved Oxygen Concentration To Fish Distribution In Jarecki Lake, Adam Sutton

Department of Environmental Studies: Undergraduate Student Theses

Abstract Water temperature and dissolved oxygen (DO) profiles were measured once every month from mid July to mid February in a relatively deep sand-pit lake in southeast Nebraska. These profiles showed depleted DO concentrations below the thermocline during summer stratification indicating areas fish will likely avoid in summer months. Colder temperatures in fall caused complete mixing of the water column allowing fish to inhabit all depths of the lake. An inverse temperature stratification occurred directly below the ice during winter months as ice cover cooled the surface water to below 4 degrees Celsius. Ice cover also blocked air – water …


Herbicides And Amphibian Populations, Zach Shirk Apr 2010

Herbicides And Amphibian Populations, Zach Shirk

Department of Environmental Studies: Undergraduate Student Theses

Amphibians are a unique class of species that are found worldwide except Antarctica and Greenland. They range in size from a few millimeters to over six feet long. Amphibian’s habitats are as various as their size, but one thing in common is that amphibians require an aquatic location to breed. Amphibians live in deserts, mountain prairies, rain forest, wetlands, and almost everywhere in between. Amphibians are an integrated part of most natural ecosystems across the world. Amphibians are a critical part of many food chains; they provide the important link between secondary and tertiary consumers. Amphibians are indicator species in …


Toxicodynamics And Biotransformation Of Azaspiracids Incorporating Liquid Chromatography-Tandem-Mass Spectrometry (Lc-Ms/Ms) Techniques., Daniel O'Driscoll Jan 2010

Toxicodynamics And Biotransformation Of Azaspiracids Incorporating Liquid Chromatography-Tandem-Mass Spectrometry (Lc-Ms/Ms) Techniques., Daniel O'Driscoll

Theses

Azaspiracids (AZAs) are a family of lipophilic polyether marine biotoxins, that have caused a number of human intoxication incidents in Europe since 1995, which was the first incident reported following the consumption by consumers of intoxicated shellfish {Mytilus edulis). This class of phycotoxins has been responsible for extended closures of shellfisheries in various locations around Europe, where levels of AZAl-3 are regulated in shellfish. Since their discovery in 1995, AZAs have become the focus of extensive research, resulting in the discovery of numerous analogues. Only AZAl and AZA2 have been found in phytoplankton and all the other analogues are believed …


Determination Of Lead, Cadmium, Zinc And Nickel Inedible Oil Products By Stripping Voltammetry., Ng Khan Loon Jan 2010

Determination Of Lead, Cadmium, Zinc And Nickel Inedible Oil Products By Stripping Voltammetry., Ng Khan Loon

Student Works (2010-2019)

Edible oil products had become an everyday food that been consumed by most of the people either for dressing or for cooking purpose. Metal has become a common contamination to the food product, which it found the way into the edible oil through environment and processing contamination such as crushing, distillation, and hydrogenation. In this Study, the main focuses of metal analysis are only confined to 4 common metals which are the Cadmium, Lead, Zinc and Nickel. These elements are selected in this study due to reason that Cadmium and Lead are commonly known for their contamination from environment and …


Application Of Solid-Phase Microextraction For The Analysis Of Polycyclic Aromatic Hydrocarbons In Hyophila Involuta As A Natural Biosensor., Elizabeth Fong Yew Mei Jan 2010

Application Of Solid-Phase Microextraction For The Analysis Of Polycyclic Aromatic Hydrocarbons In Hyophila Involuta As A Natural Biosensor., Elizabeth Fong Yew Mei

Student Works (2010-2019)

This work describes a simple and rapid extraction method by using solid-phase microextraction (SPME) technique for the determination of polycyclic aromatic hydrocarbons (PAHs) from mosses of Hyophila involuta which is found commonly and abundantly throughout Peninsular Malaysia. Mosses have been chosen in our study since they are effective bioindicators as they take up nutrients and pollutants directly from the atmosphere and they have no root system. These properties make them ideal for evaluating pollutant levels in the air over a monitored period of time. This study has been developed and optimized based on the extraction of the analytes of interest …


The Study Of Variations In The Properties Of Biodiesel On Addition Of Antioxidants, Hiranmayee Kandala Aug 2009

The Study Of Variations In The Properties Of Biodiesel On Addition Of Antioxidants, Hiranmayee Kandala

Masters Theses & Specialist Projects

This research studies variations in biodiesel upon addition of different concentrations of antioxidant and petrodiesel additives. Oxidation onset temperature, oxidation induction time, oxidative stability, thermal stability, crystallization onset temperature and moisture retention properties of the biodiesel, with and without antioxidants have been studied. Antioxidants like BHT, BHA, PrG, Vit E and Vit C were added to the biodiesel during the study. These samples were analyzed using the PDSC, TGA, DSC and TGA-SA instrumentation.

The results of this research show an improvement in the OOT, OIT and Oxidative stability of biodiesel with the addition of antioxidants and by blending the biodiesel …


Water Quality Changes In A Constructed Wetland At The Springs Preserve In Las Vegas, Nevada, Aaron Mathis Miller May 2009

Water Quality Changes In A Constructed Wetland At The Springs Preserve In Las Vegas, Nevada, Aaron Mathis Miller

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Springs Preserve near downtown Las Vegas, Nevada contains a seven-acre constructed wetland. Springs Preserve managers are planning to use water from the constructed wetland to irrigate creeks immediately north of the wetland. These creeks will be used by a variety ofaquatic wildlife, including endangered amphibians sensitive to harmful metalloids, such as selenium, lead, and arsenic.

In an attempt to answer toxicological questions about contaminant concentrations in the constructed wetland, three metals and metalloids (selenium, arsenic, and lead), two nutrients (nitrogen and phosphorus), and the major ionic species were analyzed at four sampling locations for aqueous concentrations, in two separate …


Potential Role Of Micro-Algae On Global Energy Supply, Sage Callaway-Keeley, Stephanie Huynh Apr 2009

Potential Role Of Micro-Algae On Global Energy Supply, Sage Callaway-Keeley, Stephanie Huynh

Student Research Posters

The most effective ways to reduce CO2 emissions are to improve the energy efficiency of each economic sector and to reduce the cutting of tropical and temperate forests around the world. These options, however, may not fully reach their technical and economic potential due to various political and socioeconomic. The most practical of these is to increase CO2 sinks through photosynthesis in both standing tree biomass and in ocean primary producers. The use of marine algae as CO2 sinks is for large-scale CO2 mitigation: the use of phytoplankton through Fe fertilization and macro algal (kelp) farms, which can be used …


Biofuels: A Hands-On Approach, Learning The Potential Of Utilizing Non-Food Sources, Alexandra Ham, Gabrielle Pecora, Hoaithuong Bui, Timothy Camarella, Victor Pham, Marc Ting Apr 2009

Biofuels: A Hands-On Approach, Learning The Potential Of Utilizing Non-Food Sources, Alexandra Ham, Gabrielle Pecora, Hoaithuong Bui, Timothy Camarella, Victor Pham, Marc Ting

Student Research Posters

The global energy economy is huge and thoughts of replacing large amounts of petroleum based fuels by massive levels of fermentation of grains are not realistic. On an energy basis what global agriculture produces for food will almost cover the energy demands if all of it is redirected to the production of fuels—either as alcohols for gasoline or as fat derivatives for diesel fuel. This means that chemical processes need to be developed that allow inclusion of non-food based agricultural and urban wastes as well as forest debris into the energy economy. These represent opportunities to capture new sources of …


Dispersal And Establishment Both Limit Colonization During Primary Succession On A Glacier Foreland, Chad C. Jones, Roger Del Moral Jan 2009

Dispersal And Establishment Both Limit Colonization During Primary Succession On A Glacier Foreland, Chad C. Jones, Roger Del Moral

Botany Faculty Publications

Plant colonization can be limited by lack of seeds or by factors that reduce establishment. The role of seed limitation in community assembly is being increasingly recognized, but in early primary succession, establishment failure is still considered more important. We studied the factors limiting colonization on the foreland of Coleman Glacier, Washington, USA to determine the importance of seed and establishment limitation during primary succession. We also evaluated the effects of seed predation, drought and existing vegetation on establishment. We planted seeds of seven species into plots of four different ages and found evidence that both seed and establishment limitation …


Salt Marshes As A Source Of Chromophoric Dissolved Organic Matter (Cdom) To Southern California Coastal Waters, Catherine D. Clark, Liannea P. Litz, Stanley B. Grant Jan 2008

Salt Marshes As A Source Of Chromophoric Dissolved Organic Matter (Cdom) To Southern California Coastal Waters, Catherine D. Clark, Liannea P. Litz, Stanley B. Grant

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

To determine chromophoric dissolved organic matter (CDOM) sources in Southern California coastal waters, optical properties of a river outlet and adjacent tidally flushed salt marshes were monitored (dry season; June July 2001). Average absorption coefficients doubled at ebb vs. flood tides (4.8 +/- 1.5 vs. 2.1 +/- 0.9 m(-1); 300 nm), suggesting significant salt marsh CDOM inputs into coastal waters. Average spectral slopes were not statistically different for any sites or tides (0.010 +/- 0.002 nm(-1)), consistent with salt marsh CDOM dominating coastal waters. Three-dimensional fluorescence excitation-emission matrices (EEMs) at ebb tide showed contributions from terrestrial, protein, and marine humic-like …


Dms Air/Sea Flux And Gas Transfer Coefficients From The North Atlantic Summertime Coccolithophore Bloom, Christa Marandino, Warren J. De Bruyn, Scott Miller, Eric S. Saltzman Jan 2008

Dms Air/Sea Flux And Gas Transfer Coefficients From The North Atlantic Summertime Coccolithophore Bloom, Christa Marandino, Warren J. De Bruyn, Scott Miller, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Dimethylsulfide (DMS) atmospheric and oceanic concentrations and eddy covariance air/sea fluxes were measured over the N. Atlantic Ocean during July 2007 from Iceland to Woods Hole, MA, USA. Seawater DMS levels north of 55 degrees N ranged from 3 to 17 nM, with variability related to the satellite-derived distributions of coccoliths and to a lesser extent, chlorophyll. For the most intense bloom region southwest of Iceland, DMS air/sea fluxes were as high as 300 mu mol m(-2) d(-1), larger than current model estimates. The observations imply that gas exchange coefficients in this region are significantly greater than those estimated using …


The Impact Of Acid Mine Drainage On West Little Sugar Creek, Vigo Co., In, Jodie L. Gibson Aug 2006

The Impact Of Acid Mine Drainage On West Little Sugar Creek, Vigo Co., In, Jodie L. Gibson

All-Inclusive List of Electronic Theses and Dissertations

This study evaluates the degree and extent of contamination in West Little Sugar Creek by analyzing water chemistry in the stream during low and moderate flow conditions. West Little Sugar Creek is located in Vigo County, Indiana and has been severely impacted by AMD discharging from the abandoned Green Valley Mine site. Stream water is commonly acidic (as low as pH 2.4) with elevated concentrations of Fe and Al and elevated trace elements including Ni, Zn, Cu, Cd, Cr, Co, and others, many of which exceed local and/or national surface water quality standards. Amorphous Fe and Al precipitates also form …


Nmr Investigations Of Natural Organic Matter In Forest Ecosystems, Chris E. Johnson Jan 2006

Nmr Investigations Of Natural Organic Matter In Forest Ecosystems, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.


Effect Of Humic Substance Photodegradation On Bacterial Growth And Respiration In Lake Water, Alexandre M. Anesio, William Granéli, George R. Aiken, David J. Kieber, Kenneth Mopper Jan 2005

Effect Of Humic Substance Photodegradation On Bacterial Growth And Respiration In Lake Water, Alexandre M. Anesio, William Granéli, George R. Aiken, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

This study addresses how humic substance (HS) chemical composition and photoreactivity affect bacterial growth, respiration, and growth efficiency (BGE) in lake water. Aqueous solutions of HSs from diverse aquatic environments representing different dissolved organic matter sources (autochthonous and allochthonous) were exposed to artificial solar UV radiation. These solutions were added to lake water passed through a 0.7-μm pore-size filter (containing grazer-free lake bacteria) followed by dark incubation for 5, 43, and 65 h. For the 5-h incubation, several irradiated HSs inhibited bacterial carbon production (BCP) and this inhibition was highly correlated with H2O2 photoproduction. The H2 …