Physical Sciences and Mathematics Commons^™

Theoretical Approaches To The Characterization Of Water, Aqueous Interfaces, And Improved Sampling Of Protein Conformational Changes, Alexis J. Lee

University of New Orleans Theses and Dissertations

Methods to advance the understanding of water and other aqueous systems are devel- oped. This work falls into three areas: The creation of better interaction potentials for water, improved methods for sampling configurational space, and the applications of these methods to understand systems of interest. Charge transfer has been shown by ab initio methods to be important in the water–water and water–ion interactions. A model for treating charge transfer in liquid water and aqueous systems is presented in this manuscript. The model is called Discrete Charge Transfer (DCT) and is based on the commonly-used TIP4P/2005 model, which represents the charge …

Synthesis Of 1,1-Dialkyhydrazines And Their Hydroxyl Radical Degradation In Aqueous Environments, Benjamin F. Strong

Masters Theses

Determination of hydroxyl radical rate constants are essential to ensure adequate degradation of contaminants in wastewater. Hydrazines are an important class of organic contaminants and are the focus of this research. Ten 1,1-dialkylhydrazines are synthesized by the zinc reduction of the corresponding N-nitrosamines. Their hydroxyl radical rate constants are determined using the linear accelerator at the Notre Dame Radiation Laboratory at pH 4, 7, and 10.

Their rate constants are found to depend on the protonation state of the molecule. At pH 4 the molecules are fully protonated and hydrogen atom abstraction is favored from the alkyl chains. At …

A Study Of Enhanced De-Chlorination And Bio-Remediation: Molasses Injections Into Groundwater, Brent Anderson

Natural Resources Management and Environmental Sciences

No abstract provided.

A Model To Relate Environmental Variation To Npdes Permit Violations At Thermoelectric Facilities On The Taunton River, Seth Delevan Sheldon

Graduate Doctoral Dissertations

Large thermoelectric facilities are issued permits to discharge high volume, high temperature effluents as part of the National Pollutant Discharge Elimination System (NPDES). Once-through cooled power plants are especially dependent on large quantities of cool water to operate. When ambient temperatures are high or streamflow is very low, power plant managers must reduce (i.e., "dial back") energy generation in order to avoid violating their NPDES permit limitations. Sudden dial-back can have human health impacts when electricity is no longer available to provide cooling or other vital services. A superior system of electricity and environmental management would reduce the probability of …

Dispersibility Of And Adsorption On Functionalized Carbon Nanotubes, Susana Addo Ntim

Dissertations

As the applications of carbon nanotubes (CNTs) proliferate, mass production and widespread use of these nanocarbons will continue to rise. While raw, unrefined, and hydrophobic carbon nanotubes tend to settle out of aqueous media/environments, water dispersible, functionalized CNTs (F-CNTs) will contaminate water resources and will also be highly bioavailable on exposure. Therefore, there is a need to develop an understanding of the fate of F-CNTs in aqueous media.

The colloidal behavior of aqueous dispersions of F-CNTs formed via carboxylation and polymer wrapping with polyvinyl pyrrolidone (PVP) is investigated. The presence of polymer on the nanotube surface provides steric stabilization, and …

Measured Rates Of D2 Abstraction In H2o+ , D2 Substitution In H2do+ And Charge Transfer Of He2+ With Noble And Other Gases At <1ev, Chrysanthos Kyriakides

UNLV Theses, Dissertations, Professional Papers, and Capstones

Experimental determination of the rate coefficient values of deuterium abstraction in water ions and deuterium substitution in hydronium ions can improve the understanding of D/H in water at planetary atmospheres, cometary atmospheres, and interstellar medium. Using a cylindrical ion trap, (CIT) and time of flight (TOF) mass spectrometry, a number of measurements at energies below 1 eV have been performed. The deuterium abstraction rate coefficient in water ions, H₂O⁺, and an upper limit for the hydrogen-deuterium substitution rate coefficient in monodeuterated hydronium ion, H₂DO⁺, have been measured. Both the abstraction and substitution …

Water Infrastructure Challenges In Urbanizing Environments: A Case Study Of The 2009 Logan Canal Landslide, Kathryn Davis Henderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In July, 2009 in Logan, Utah, a wet, steep hillside failed, leveling a home below and destroying an irrigation canal that ran along the hill. Three people were killed. The event and the resulting policy changes present an opportunity to uncover how frames, or social constructions, play into the policy development cycle. This case also uncovers the nuances involved when old infrastructure takes on new social meanings. Planners and policymakers that pay attention to frames and social dimensions may be able to minimize conflict.

The landslide received immediate media attention and spurred state legislation on canal safety. The event had …

Sustainable Water Management In The University Of Texas At El Paso, Cora Martinez

Open Access Theses & Dissertations

This thesis showed how to improve water and financial savings for UTEP and El Paso by improving water conservation and sustainability of the UTEP campus. The goals of this research were successfully accomplished by focusing in three principal objectives.

1. Analyze historical data of water consumption of the UTEP campus for the past decade.

2. Evaluate water consumption to quantify water consumption by buildings and type of use, as well as provide recommendations for water and cost savings.

3. Synthesize a water management framework within the UTEP Facilities' Geographic Information System (GIS) for long-term monitoring and evaluation

Temporal And Spatial Assessment Of Pahs In Water, Sediment, And Oysters As A Result Of The Deepwater Horizon Oil Spill, Meghan Christina Dailey

Electronic Theses and Dissertations

On April 20, 2010, BP's Deepwater Horizon oil rig exploded leaking over 200 million gallons of crude oil into the Gulf of Mexico for 84 days. Exposure to oil-associated polycyclic aromatic hydrocarbons (PAHs) in the water and sediment could severely impact the aquatic organisms inhabiting the Gulf of Mexico (i.e. developmental defects, reproductive effects, death, etc.). Therefore, water, sediment and oyster, Crassostrea virginica, samples were collected approximately bimonthly between May 26 and November 30, 2010 from multiple sites along the Gulf Coast, namely, two sites in Mobile Bay (Denton and Sand Reefs at 1 or 0.1 m above the bay …

Evaluation Of Soil Sustainability Along The Rio Grande In West Texas: Changes In Salt Loading And Organic Nutrients Due To Farming Practices, Christine L. Cox

Open Access Theses & Dissertations

Growing populations demand an increase in the amount of food being produced, which in turn, puts pressure on the productivity and sustainability of soils. The use of flood irrigation from the Rio Grande has greatly increased the salinity, sodicity, and enhanced leaching of nutrients in the Rio Grande Basin soils. To evaluate soil health, water and soil samples were collected from two pecan, one cotton, and one alfalfa field in western Texas. Each site was equipped with sensors to measure soil moisture, temperature, and electrical conductivity (EC), along with lysimeters at depths of 15, 30, and 60 cm to collect …

Water Mass Balances For The Rio Grande/Bravo From Fort Quitman, Texas To Foster Ranch Near Langtry, Texas: An Assessment Of Factors, Ramiro Lujan

Open Access Theses & Dissertations

ABSTRACT

Water availability is declining in many regions of the planet, particularly in arid and semi-arid regions. Water bodies located in these regions, like the Rio Grande/Bravo at the U.S. - Mexico border, are subjected to high water demands. This research project makes an assessment of the spatial and temporal variability of elements intervening in the water mass balance for the section of the Rio Grande/Bravo between Fort Quitman and Langtry, Texas during the time period extending from January 1990 through December 2005. This document mentions the main Rio Grande/Bravo stakeholders from the U.S. and Mexico, and describes issues related …