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- Air pollution (1)
- Alpha spectroscopy (1)
- Analytic; Diels-Alder reaction; Plastic foams; Polyurethanes (1)
- Carbodiimides; Chemistry (1)
- Crime scene investigations (1)
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- Desert varnish (1)
- Forensic techniques (1)
- Microprecipitation (1)
- Nuclear forensics (1)
- Power plants (1)
- Precipitation (1)
- Radiochemistry (1)
- Soil analysis (1)
- Soil contaminates (1)
- Soil sample preservation (1)
- Solid-phase microextraction (SPME) sample preparation technique (1)
- Source preparation (1)
- Trace metals (1)
- Volatile organic compounds (VOCs) (1)
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
The Synthesis And Systematic Evaluation Of Modified Polymeric Foams And Electrically Conductive Polyimide/Carbon/Metal Films, John Macharia Kinyanjui
The Synthesis And Systematic Evaluation Of Modified Polymeric Foams And Electrically Conductive Polyimide/Carbon/Metal Films, John Macharia Kinyanjui
UNLV Theses, Dissertations, Professional Papers, and Capstones
Thermally processed PU foams are examined as a function of processing temperatures (25, 45, 65, and 85°C) at the side, middle, and center of a simple cylindrical mold. The PU foams show both chemical and morphological differences as a function of the processing temperature and radial position within the mold. Thermal degradation of uretoneimine structures, the emergence of carbodiimide structures, and extent of reaction of isocyanate groups are measured using photoacoustic FTIR spectroscopy. Chemical gradients and morphology differences between the side, middle, and center of the molded foam are observed for all processing temperatures. The data indicate that thermal activation …
Desert Varnish As An Indicator Of Modern-Day Air Pollution In Southern Nevada, Piotr Nowinski
Desert Varnish As An Indicator Of Modern-Day Air Pollution In Southern Nevada, Piotr Nowinski
UNLV Theses, Dissertations, Professional Papers, and Capstones
Rock varnish, often called desert varnish, is a slow-growing, manganese-rich coating that accumulates on exposed rock surfaces. The mechanism of varnish formation is not fully understood, however, most authors agree that varnishes derive their components from the atmosphere. The main goal of this study was to demonstrate the potential use of desert varnish as a passive environmental monitor of present and past atmospheric pollution. Analysis of varnishes is a new field that can potentially provide records of pre-anthropogenic levels of atmospheric metals and other environmental pollutants. To evaluate the potential of desert varnish as an environmental monitoring tool, the following …
Optimization Of The Microprecipitation Procedure For Nuclear Forensics Applications, Lyndsey Renee Kelly
Optimization Of The Microprecipitation Procedure For Nuclear Forensics Applications, Lyndsey Renee Kelly
UNLV Theses, Dissertations, Professional Papers, and Capstones
Microprecipitation has become one of the most widely used sample preparation techniques for alpha spectroscopy. Many factors during the precipitation process can affect the yield and energy resolution by adding unwanted mass to the sample. Current applications in nuclear forensics call for an optimization of energy resolution and yield in order to improve identification and quantify specific radionuclides. The purpose of this research is to determine the optimal parameters used for microprecipitation. The optimal solution temperature, precipitation time, carrier amount, and hydrofluoric acid amount are used to investigate the influence of varying the type of carrier, as well as, the …
Analytical Method Development For Determination Of Volatile Organic Compounds In Calcareous Desert Soil, Mary F. Turner
Analytical Method Development For Determination Of Volatile Organic Compounds In Calcareous Desert Soil, Mary F. Turner
UNLV Theses, Dissertations, Professional Papers, and Capstones
Soil sample preservation for volatile organic compound analysis generally requires short sample holding times or preservation of the sample's chemical constituents with sodium bisulfate (NaHSO 4 ). Calcareous soils cannot be preserved using NaHSO4 because effervescence will promote the loss of analytes, and short holding times before analysis are not practical for remote sampling locations. An experimental approach was developed for determination of volatile organic compounds (VOCs) in soil that utilizes solid sorbents for sample preservation and solid-phase microextraction (SPME) sample preparation technique coupled with gas chromatography/mass spectrometry (GC/MS) for analysis. Solid sorbents are used to sequester readily extractable (vapor …