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UNLV Retrospective Theses & Dissertations

Theses/Dissertations

Chemical

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Numerical Modeling Of High Temperature Shell And Tube Heat Exchanger And Chemical Decomposer For Hydrogen Production, Gayatri Kuchi Jan 2008

Numerical Modeling Of High Temperature Shell And Tube Heat Exchanger And Chemical Decomposer For Hydrogen Production, Gayatri Kuchi

UNLV Retrospective Theses & Dissertations

This thesis deals with the development of a three-dimensional numerical model of high temperature shell and tube heat exchanger and chemical decomposer to examine the percentage decomposition of a sulfur trioxide gaseous mixture for the production of hydrogen by the sulfur-iodine thermochemical water splitting cycle, a candidate cycle in the U.S. Department of Energy Nuclear Hydrogen Initiative. A counter flow type straight tube shell and heat exchanger concept is chosen for the analysis. The reacting fluid is a mixture of sulfur trioxide gas and water vapor inside the tubes of the heat exchanger and high temperature helium is the gas …


Chemical Synthesis And Characterization Of Aniline Based Palladium Composites And Complexes, Jade Lorrayne Morgan Jan 2008

Chemical Synthesis And Characterization Of Aniline Based Palladium Composites And Complexes, Jade Lorrayne Morgan

UNLV Retrospective Theses & Dissertations

The chemical synthesis of aniline based palladium materials was achieved by the use of the chemical oxidants, PdCl4 2- and PdCl62-. Complex formation was favored by using aniline and polymer formation was favored by the use of n-phenyl-1,4-phenylenediamine (NPPD). All materials were prepared with or without acid. Also, Characterization techniques such as FTIR spectroscopy, UV-Vis spectroscopy, Scanning Electron Microscopy, Thermogravimetric Analysis and X-ray Photoelectron Spectroscopy were used; Hydrogen sorption studies were carried out using a GC/Hydrogen Generator. The aniline complexes had sorption properties up to 1.5% and the NPPD composites showed sorption up to 0.7%. It was found that the …


Differences In Soil Physical, Chemical And Mineralogical Properties Between Inhabited And Uninhabited Arctomecon Californica Habitats, Rekha Saxena Jan 2005

Differences In Soil Physical, Chemical And Mineralogical Properties Between Inhabited And Uninhabited Arctomecon Californica Habitats, Rekha Saxena

UNLV Retrospective Theses & Dissertations

Vascular plant endemism to gypsum soils in arid environments is fairly rare; in southern Nevada few plant species are known to exist solely on gypsum soils and the explanation for why they exist on these soils is even less understood. One such species, commonly known as Las Vegas Bearpoppy (Arctomecon californica), is believed to be a gypsophile endemic occurring on substrates derived from the Moenkopi and Horse springs geological formations in southeastern Nevada and northwestern Arizona. During the past two decades, populations of A. californica have been declining mostly around the rapidly developing urban areas on public lands on the …


Prediction Of Struvite Formation Potential In Ebpr Digested Sludge Using Mass Balances, Batch Precipitation Tests, And Chemical Equilibrium Modeling, Hyunju Jeong Jan 2004

Prediction Of Struvite Formation Potential In Ebpr Digested Sludge Using Mass Balances, Batch Precipitation Tests, And Chemical Equilibrium Modeling, Hyunju Jeong

UNLV Retrospective Theses & Dissertations

Digested sludge liquors from wastewater treatment plants that include enhanced biological phosphorus removal (EBPR) in their treatment process have the potential to form struvite (MgNH4PO4·6H 2O). The potential can be determined by the concentrations of struvite constituents including phosphorus, ammonium, and magnesium. Phosphorus concentration of digested sludge liquors is expected to increase when EBPR is introduced to wastewater treatment plants because phosphorus accumulating organisms (PAOs) can accumulate phosphorus beyond their metabolic needs and phosphosphorus can be relased when they are digested anaerobically. The work presented in this thesis focuses on determining the potential for struvite formation at the City of …


Potential Use Of Ultrasound In Chemical Monitoring, Grazyna Elzbieta Orzechowska Jan 1993

Potential Use Of Ultrasound In Chemical Monitoring, Grazyna Elzbieta Orzechowska

UNLV Retrospective Theses & Dissertations

The objective of this study was to examine the potential of combining sonication with other technologies for monitoring specific classes of organic pollutants in water. The research specifically addressed using ultrasonic processors to decompose organochlorine compounds into ions which could be detected using a specific ion electrode as a screening method for organochlorine pollutants. Changes in chloride, conductivity, and pH were measured using commercially available equipment before and after sonication in order to detect the presence of the organochlorine pollutant. Chloride ion could be detected in aqueous solutions of low ppm concentrations of carbon tetrachloride, chloroform, and trichloroethylene after one …