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Breaking The Language Barrier: Equitable Assessment In General Chemistry, Eshani Lee May 2018

Breaking The Language Barrier: Equitable Assessment In General Chemistry, Eshani Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Because language provides the framework through which knowledge is constructed, it is crucial to consider the ways in which students with limited English proficiencies are able to express their understanding. English language learners (ELLs) make up a significant portion of the student body in the education system and represent many ethnic and racial minorities in STEM (Science, Technology, Engineering & Mathematics) fields (Burke & Mattis, 2007). Despite the national push to build a more diversified, STEM-ready workforce, there is little research that considers the way ELLs are assessed in STEM courses at the postsecondary level. Literature reports that science tests …


Simultaneous Determination Of Multiple Actinide Elements In A Variety Of Soils Utilizing A Standardized Sequential Extraction Protocol, Sherry Alina Faye Dec 2014

Simultaneous Determination Of Multiple Actinide Elements In A Variety Of Soils Utilizing A Standardized Sequential Extraction Protocol, Sherry Alina Faye

UNLV Theses, Dissertations, Professional Papers, and Capstones

To obtain a better understanding of the mobility of actinide element contaminants in the environment, the association of the contaminants with specific host phases of soils and sediments must be investigated. This investigation is most commonly conducted using sequential extraction techniques that employ the selective dissolution of soil phases with increasingly aggressive chemical treatment. Though several sequential extraction studies exist in literature, conclusions cannot be made by direct comparison of data due to the lack of uniformity in the protocols used. This work aims to continue development of a standard sequential extraction protocol and expanding its capabilities to include the …


Characterization And Optimization Of Extraction Chromatography Resins For Rapid Separations For Safeguard And Nuclear Forensics Purposes, Audrey Roman May 2014

Characterization And Optimization Of Extraction Chromatography Resins For Rapid Separations For Safeguard And Nuclear Forensics Purposes, Audrey Roman

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this work, extraction chromatography resins, DGA and UTEVA, were characterized under various conditions in order to identify novel rapid separations for safeguards and nuclear forensic purposes. For safeguards purposes, mixed matrices containing some of the largest components found in used fuel and either Am, Pu, or U were characterized on DGA and UTEVA resins in order to determine any effects from the addition of these constituents. Results indicated that 5 M HNO3 would be an optimal loading condition due to the consistent actinide adsorption in the presence of the additional used fuel components. Investigations of varying the anion …


Nitrate Ion Effects On Uranium Chemistry In The Tributylphosphate-Dodecane System, Amber Dawn Wright Jan 2008

Nitrate Ion Effects On Uranium Chemistry In The Tributylphosphate-Dodecane System, Amber Dawn Wright

UNLV Retrospective Theses & Dissertations

Understanding the role of nitrate in the speciation of actinides is important in order to determine the necessary data for extraction modeling of the UREX process. The focus of this project is on the fundamental chemistry of uranium (U) in the tributyl phosphate (TBP) extraction system, with emphasis on the effect of nitrate on actinyl speciation. Speciation calculations can be performed if stability and solubility constants for the chemical species formed under the examined conditions are known. The stability constant of the uranyl-TBP complex was evaluated under a variety of conditions. The variables were nitric acid, uranyl, total nitrate concentration, …


An Assessment Of The Potential To Use Water Chemistry Parameters To Define Ground Water Flow Pathways At Grand Canyon National Park, Arizona, Kim Alison Zukosky Jan 1995

An Assessment Of The Potential To Use Water Chemistry Parameters To Define Ground Water Flow Pathways At Grand Canyon National Park, Arizona, Kim Alison Zukosky

UNLV Retrospective Theses & Dissertations

The purpose of this study is to assess the potential to use water chemistry parameters to determine ground water flow pathways at the south rim of Grand Canyon National Park, Arizona. South rim spring, ground, and surface waters and one north rim spring were sampled from September 1992 through September 1993. Field measurements (pH, electrical conductivity, alkalinity, temperature, total dissolved solids, and dissolved oxygen), major anion (fluoride, chloride, bromide, nitrate, phosphate, and sulfate) concentrations, selected trace element concentrations, and the ratios of the stable isotopes of oxygen and hydrogen. Major anion, trace element, and field measurement data were analyzed using …