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The Radiochemistry of Selenium

Description: A review of the nuclear and chemical features of selenium, a discussion of problems of sample dissolution and counting techniques, and a collection of radiochemical procedures for the element as found in the literature are presented. (94 references) (M.C.G.)
Date: April 1961
Creator: Leddicotte, G. W.
Partner: UNT Libraries Government Documents Department

Selenium Poisoning of Wildlife and Western Agriculture: Cause and Effect

Description: This project examined the hypothesis that selenium contamination is not the principal cause of the decline of endemic fish species in the Upper Colorado Basin. Activities employed to test this hypothesis included a reconnaissance of locations altered by recent road construction, a re-interpretation of available literature regarding selenium toxicity, and the interpretation of unpublished data obtained from the Upper Colorado Basin Fish Recovery Program. The project demonstrates that most of the evidence implicating selenium is circumstantial.
Date: February 1, 2000
Creator: Korte, N.E.
Partner: UNT Libraries Government Documents Department

A Sprectrochemical Method for the Determination of Selenium

Description: A report about selenium which can be determined in pyrite, chalcocite, and marcasite by a spectrochemical method that is simple and rapid, and that requires no complicated arrangement of spectrographic equipment, or chemical pretreatment of samples.
Date: June 1957
Creator: Waring, Claude L.; Worthing, Helen & Hazel, Katherine V.
Partner: UNT Libraries Government Documents Department

Some Compounds of Plutonium With Metalloid Elements

Description: From abstract: "Experimental methods of the type employed for alloy preparation in metallurgical research have been used in attempts to prepare compounds of plutonium with four different metalloid elements: phosphorous, arsenic, selenium, and tellurium. By means of their X-ray diffraction patterns the existences of six previously unknown compounds have been established, but the composition and crystal structures of only three of the compounds have been determined."
Date: 1955
Creator: Gorum, Alvin Eugene
Partner: UNT Libraries Government Documents Department

Pressure dependence of donor excitation spectra in AlSb

Description: We have investigated the behavior of ground to bound excited-state electronic transitions of Se and Te donors in AlSb as a function of hydrostatic pressure. Using broadband far-infrared Fourier transform spectroscopy, we observe qualitatively different behaviors of the electronic transition energies of the two donors. While the pressure derivative of the Te transition energy is small and constant, as might be expected for a shallow donor, the pressure derivatives of the Se transition energies are quadratic and large at low pressures, indicating that Se is actually a deep donor. In addition, at pressures between 30 and 50 kbar, we observe evidence of an anti-crossing between one of the selenium electronic transitions and a two-phonon mode.
Date: January 16, 2002
Creator: Hsu, L.; McCluskey, M.D. & Haller, E.E.
Partner: UNT Libraries Government Documents Department

The Association between Hantavirus Infection and Selenium Deficiency in Mainland China

Description: This article studies the role of selenium concentration in hemorrhagic fever with renal syndrome (HFRS) caused by hantaviruses, using a multidisciplinary approach combining ecological analysis with preliminary experimental data.
Date: January 20, 2015
Creator: Fang, Liqun; Goeijenbier, Marco; Zuo, Shu-Qing; Wang, Li-Ping; Liang, Song; Klein, Sabra L. et al.
Partner: UNT College of Arts and Sciences

Effect of palladium dispersion on the capture of toxic components from fuel gas by palladium-alumina sorbents

Description: The dispersion and location of Pd in alumina-supported sorbents prepared by different methods was found to influence the performance of the sorbents in the removal of mercury, arsine, and hydrogen selenide from a simulated fuel gas. When Pd is well dispersed in the pores of the support, contact interaction with the support is maximized, Pd is less susceptible to poisoning by sulfur. and the sorbent has better long-term activity for adsorption of arsine and hydrogen selenide. but poorer adsorption capacity for Hg. As the contact interaction between Pd and the support is lessened the Pd becomes more susceptible to poisoning by sulfur. resulting in higher capacity for Hg, but poorer long-term performance for adsorption of arsenic and selenium.
Date: January 1, 2011
Creator: Baltrus, J.P.; Granite, E.J.; Rupp, E.C.; Stanko, D.C.; Howard, B. & Pennline, H.W.
Partner: UNT Libraries Government Documents Department

FY08 Annual Report: Amorphous Semiconductors for Gamma Radiation Detection (ASGRAD)

Description: This is the annual report for an old project funded by NA22. The purpose of the project was to develop amorphous semiconductors for use as radiation detectors. The annual report contains information about the progress made in synthesizing, characterizing, and radiation response testing of these new materials.
Date: February 1, 2009
Creator: Johnson, Bradley R.; Riley, Brian J.; Crum, Jarrod V.; Ryan, Joseph V.; Sundaram, S. K.; McCloy, John S. et al.
Partner: UNT Libraries Government Documents Department

Structure of bis(ethylenedithio)tetrathiafulvalenium dichlorocyanoselenate (2:1), (BEDT-TTF){sub 2}Cl{sub 2}SeCN

Description: The electron donor molecule BEDT-TTF has yielded approximately 50 superconductors to date. In addition, numerous other salts with a variety of electrical and magnetic properties have been discovered. Recently, the authors reported a semiconducting salt of BEDT-TTF with the novel T-shaped anion Br{sub 2}SeCN{sup {minus}2}. The crystallographic analysis of that salt revealed a near-centrosymmetric triclinic structure, except for the symmetry-breaking anion. On the basis of a Hamilton R-value test, the non-centrosymmetric space group P1 with ordered anions was preferred over centrosymmetric P{bar 1} with disordered anions. In this paper, the authors present the synthesis and crystal structure of the isostructural chlorine-analogue salt (BEDT-TTF){sub 2}Cl{sub 2}SeCN.
Date: December 31, 1995
Creator: Geiser, U.; Schlueter, J.A.; Dudek, J.D. & Williams, J.M.
Partner: UNT Libraries Government Documents Department

Development and evaluation of a hydride technique for As, Sb, and Se determinations by inductively coupled plasma-atomic emission spectroscopy

Description: A literature review of hydride techniques, experimental facilities, development and evaluation of a hydride technique, and interelement effects are covered. Suggestions for future work are given. (LK)
Date: January 1, 1977
Creator: Sloat, S. S.
Partner: UNT Libraries Government Documents Department

Selenium isotope geochemistry: A new approach to characterizing the environmental chemistry of selenium. Final report

Description: High levels of selenium in the environment will be a prominent water quality issue in the western United States for many years. Selenium accumulation is linked to increased rates of death and deformity in migratory birds, blind staggers in livestock, and selenosis in humans. In California, agricultural drain waters and oil refinery effluent contribute to high selenium content in the San Joaquin Valley and the San Francisco Bay. The importance of these industries to California`s economy precludes simple abatement, while the complexity of selenium cycling precludes simple remediation. The purpose of this project is to measure variations in the isotopic composition of selenium in water and soil samples caused by natural processes and to show, for the first time, the value of isotopic measurements in characterizing selenium pollution. The research seeks to identify sources of selenium pollution, determine processes in the selenium cycle, and support selenium remediation studies. The project required the successful integration of three components: (1) appropriate sampling a field setting showing Se enrichment and possibly isotopic fractionation, (2) analytical chemical methods for isolating and purifying the various species of Se in waters and sediment, and (3) mass spectroscopic instrumentation for high precision isotope abundance measurements.
Date: February 5, 1997
Creator: Volpe, A.M. & Esser, B.K.
Partner: UNT Libraries Government Documents Department

Update to modeling soil selenium concentrations in the shallow soil profile at Kesterson Reservoir Merced County, California

Description: A mass balance model was developed to predict concentrations of water-extractable selenium in surface and subsurface soil by extrapolating the trend observed from 6 years of soil monitoring data collected at Kesterson Reservoir. Correlations between observed and calculated concentrations indicate that the major trends and year-to-year variations are well represented with the model. Results from this exercise were then used, under three climatic scenarios, to simulate the evolution of the soluble selenium inventory 25 years into the future. Based on these simulations, we expect that the availability of the soluble selenium inventory has most likely reached peak levels, and is now declining. However, year-to-year climatic variations may influence the rate of decline, and occasionally reverse this prevailing trend.
Date: January 1, 1996
Creator: Wahl, C. & Benson, S. M.
Partner: UNT Libraries Government Documents Department

Control of Trace Metal Emissions During Coal Combustion

Description: Emissions of toxic trace metals in the form of metal fumes or submicron particulates from a coal-fired combustion source have received greater environmental and regulatory concern over the past years. Current practice of controlling these emissions is to collect them at the cold-end of the process by air-pollution control devices (APCDs) such as electrostatic precipitators and baghouses. However, trace metal fumes may not always be effectively collected by these devices because the formed fumes are extremely small. The proposed research is to explore the opportunities for improved control of toxic trace metal emissions, alternatively, at the hot-end of the coal combustion process, i.e., in the combustion chamber. The technology proposed is to prevent the metal fumes from forming during the process, which would effectively eliminate the metal emission problems. Specifically, the technology is to employ suitable sorbents to (1) reduce the amount of metal volatilization during combustion and (2) capture volatilized metal vapors. The objectives of the project are to demonstrate the technology and to characterize the metal capture process during coal combustion in a fluidized bed combustor. The project was started on July 1, 1994 and this is the thirteenth quarterly technical progress report. Specifically, the following progress has been made during this performance period from July 1, 1997 through September 30, 1997.
Date: October 1, 1997
Creator: Ho, Thomas C.
Partner: UNT Libraries Government Documents Department