171 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "chemistry"  
Results: 1 - 24 next
open access

Pentamethylcyclopentadienyl and bis(trimethylsilyl)amido complexes of the di- and trivalent lanthanides

Description: The reaction of the divalent iodides YbI/sub 2/ and EuI/sub 2/ with NaN(SiMe/sub 3/)/sub 2/ has provided pentane-soluble, monomeric derivatives of the divalent lanthanides. These compounds are isolated as the solvated species Eu(N(SiMe/sub 3/)/sub 2/)/sub 2/L/sub 2/ (L = thf or 1,2-dme), Yb(N(SiMe/sub 3/)/sub 2/)/sub 2/(thf)/sub 1/ /sub 5/ and Yb(N(SiMe/sub 3/)/sub 2/)/sub 2/L/sub 2/ (L = 1,2-dme or OEt/sub 2/), or as the sodium salts NaM(N(SiMe/sub 3/)/sub 2/)/sub 3/ (M = Eu or Yb). The pentam… more
Date: March 1, 1982
Creator: Tilley, T. D.
Partner: UNT Libraries Government Documents Department
open access

Influence of nitrogen on the sensitization, corrosion, mechanical, and microstructural properties of austenitic stainless steels. First annual progress report

Description: During this first year of the project, the research effort has concentrated on the electrochemical aspects of the effect of nitrogen on austenitic steels. The status of all the individual project tasks are outlined briefly, and then more detailed results of the electrochemical studies conducted so far are reported. Highlights of this quarter are: (1) nitrogen additions of up to 0.16 wt % retard sensitization of 18Cr-8Ni austenitic stainless steels. However, nitrogen additions to levels above ap… more
Date: April 1, 1982
Creator: Clark, W.A.T. & Macdonald, D.D.
Partner: UNT Libraries Government Documents Department
open access

Mechanisms for radiation damage in DNA. Progress report, January 1, 1982-December 31, 1982

Description: In this project several mechanisms are proposed for radiation damage to DNA constituents and DNA, and a series of experiments utilizing electron spin resonance spectrometry to test the proposed mechanisms have been detailed. In the past studies have concentrated chiefly on the direct effect of radiation on DNA. We are currently investigating irradiated systems of DNA constituents which may shed light on indirect effects. In addition, studies of radiation effects on lipids have been undertaken w… more
Date: May 1, 1982
Creator: Sevilla, M. D.
Partner: UNT Libraries Government Documents Department
open access

Orientation study of the Lake Sunapee area, New Hampshire. National Uranium Resource Evaluation Program

Description: An orientation study was conducted in the area of Lake Sunapee, New Hampshire, in preparation for a hydrogeochemical and stream sediment reconnaissance in glacial terrain. The study was carried out by the Savannah River Laboratory as part of the National Uranium Resource Evaluation (NURE). Ground water, lake water, stream water, lake sediment, and stream sediment samples were collected at 188 sites. The concentrations of uranium and other elements were determined by neutron activation analysis.… more
Date: August 1, 1982
Creator: Karfunkel, B. S. & Sargent, K. A.
Partner: UNT Libraries Government Documents Department
open access

Analytical Chemistry Division. Annual progress report for period ending December 31, 1981

Description: The functions of the Analytical Chemistry Division fall into three general categories: (1) analytical research, development, and implementation; (2) programmatic research, development and utilization; (3) technical support. The Division is organized into five major sections each of which may carry out any type of work falling into the thre categories mentioned above. Chapters 1 through 5 of this report highlight progress within the five sections which are: analytical methodology; mass and emiss… more
Date: April 1, 1982
Creator: Lyon, W. S.
Partner: UNT Libraries Government Documents Department
open access

Tested method to minimize plutonium assay discrepancies between laboratories

Description: Plutonium assay differences are frequently observed between laboratories exchanging plutonium dioxide powders. These differences are commonly the result of chemical changes and/or nonhomogeneities in sampled materials. The irregularities are often caused by moisture absorption during sampling, packaging, shipment, and storage of the materials. A method is proposed which eliminates the effects of chemical change in samples, particularly moisture absorption, and minimizes sampling error. A nondes… more
Date: January 29, 1982
Creator: Seiler, R. J.; Goss, R. L.; Rodenburg, W. W. & Rogers, D. R.
Partner: UNT Libraries Government Documents Department
open access

Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 3. Calcareous ooze

Description: The physicochemical forms and partitioning of corrosion products released from stainless steel upon exposure to selected environmental conditions is the subject of this investigation. This report describes the influence of calcareous sediment on the rate of release and fate of corrosion products produced when neutron-activated stainless steel specimens were exposed to a Globigerina ooze taken from the Northeast Pacific Ocean. The calcareous ooze used in this study consists largely of planktonic… more
Date: April 1, 1982
Creator: Schmidt, R. L.
Partner: UNT Libraries Government Documents Department
open access

Determination of light elements in amalgam restorations. [Dental amalgam]

Description: Rutherford backscattering has been used to measure the major elemental compositions in the near-surface regions of freshly prepared and used samples of dental amalgam. A depletion from bulk stoichiometry of the major elements, which indicates an accumulation of lighter elements on the surface of the materials, has been observed. Increases in the F, Na, Cl, P, O, C, and N concentrations between freshly prepared samples and used samples were measured by observation of gamma rays produced by proto… more
Date: January 1, 1982
Creator: Hanson, A. L.; Jones, K. W.; Kraner, H. W.; Osborne, J. W. & Nelson, G. V.
Partner: UNT Libraries Government Documents Department
open access

Calculations of increased solar UV fluxes and DUV doses due to stratospheric-ozone depletions

Description: Accurate radiative transfer calculations are performed in the middle ultraviolet spectral region for aerosol-loaded atmospheres with the goal of determining the solar irradiance at the ground and quantifying the irradiance perturbations due to the presence of aerosols and various ozone depletions. The extent of the increase of UV-B radiation as a function of wave-length and solar zenith angle is calculated for five model atmospheres. In addition, the damaging ultraviolet dose rates and radiatio… more
Date: February 1, 1982
Creator: Zardecki, A. & Gerstl, S.A.W.
Partner: UNT Libraries Government Documents Department
open access

Radiological and Environmental Research Division, Center for Human Radiobiology. Annual report, July 1980-June 1981. [Lead abstract]

Description: Separate abstracts were prepared for the 22 papers of this annual report of the Center for Human Radiobiology. Abstracts were not written for 2 appendices which contain data on the exposure and radium-induced malignancies of 2259 persons whose radium content has been determined at least once. (KRM)
Date: March 1, 1982
Partner: UNT Libraries Government Documents Department
open access

Geothermal assessment of the MX deployment area in Nevada. Final report, April 1, 1981-April 30, 1982

Description: A preliminary geothermal resource assessment of the MX deployment area in Nevada focused on Coyote Spring Valley in southeastern Nevada. Initially, an extensive literature search was conducted and a bibliography consisting of 750 entries was compiled covering all aspects of geology pertaining to the study area. A structural study indicates that Coyote Spring Valley lies in a tectonically active area which is favorable for the discovery of geothermal resources. Hot water may be funneled to the n… more
Date: June 1, 1982
Creator: Trexler, D.T.; Bruce, J.L.; Cates, D.; Dolan, H.H. & Covington, C.H.
Partner: UNT Libraries Government Documents Department
open access

Fluid sampling and chemical modeling of geopressured brines containing methane. Final report, March 1980-February 1981

Description: The development of a flowthrough sampler capable of obtaining fluid samples from geopressured wells at temperatures up to 400/sup 0/F and pressures up to 20,000 psi is described. The sampler has been designed, fabricated from MP35N alloy, laboratory tested, and used to obtain fluid samples from a geothermal well at The Geysers, California. However, it has not yet been used in a geopressured well. The design features, test results, and operation of this device are described. Alternative sampler … more
Date: July 1, 1982
Creator: Dudak, B.; Galbraith, R.; Hansen, L.; Sverjensky, D. & Weres, O.
Partner: UNT Libraries Government Documents Department
open access

Progress report, April 1, 1981 to March 31, 1982

Description: Our experiments on chemical reactions might be described by a laser specialist as pump and probe experiments. The pump process is a photodissociation and the probe process is a laser induced fluorescence (LIF). Both these processes would be somewhat limited if they were confined to one photon excitations. For example, to probe vibrationally and rotationally excited CO molecules one can conveniently use Bernheim's technique of exciting the A'..pi.. reverse arrow X'..sigma.. transition in CO by a… more
Date: January 1, 1982
Partner: UNT Libraries Government Documents Department
open access

International safeguards: experience and prospects

Description: IAEA safeguards have been applied to over 95% of the nuclear material and facilities outside of the nuclear weapon states. The present system of nonproliferation agreements implemented by IAEA safeguards likely will not be changed in the foreseeable future. Instruments used for nondestructive analysis are described: portable multichannel analyzer, high-level neutron coincidence counter, active well coincidence counter, and neutron coincidence collar. 7 figs. (DLC)
Date: January 1, 1982
Creator: Keepin, G. R. & Menlove, H. O.
Partner: UNT Libraries Government Documents Department
open access

Electrochemistry applied to biomass. Progress report, October 1980-September 1981

Description: The electrochemical conversion of biomass-derived compounds, obtained through thermochemical pretreatments, into valuable organic chemicals, petrochemical substitutes, and energy-intensive chemicals is investigated. A hardwood-derived lignin obtained from ethanol extraction of the explosively depressurized aspen has been investigated. We have partially characterized this lignin material, and have also submitted it to electrolyses under controlled potential. The electrolytic conditions employed … more
Date: April 1, 1982
Creator: Chum, H. L.
Partner: UNT Libraries Government Documents Department
open access

Krypton retention on solid adsorbents. [Activated alumina; hydrogen mordenite, silver mordenite, sodium mordenite, cerium mordenite-H, cerium mordenite-Na, potassium mordenite-H, potassium mordenite-Na]

Description: An experimental laboratory program was conducted to develop economical solid adsorbents for the retention of krypton from a dissolver off-gas stream. The study indicates that a solid adsorbent system is feasible and competitive with other developing systems which utilize fluorocarbon absorption nd cryogenic distillation. This technology may have potential applications not only in nuclear fuel reprocessing plants, but also in nuclear reactors and in environmental monitoring. Of the 13 prospectiv… more
Date: January 1, 1982
Creator: Monson, P.R. Jr.
Partner: UNT Libraries Government Documents Department
open access

Uranium immobilization and nuclear waste

Description: Considerable information useful in nuclear waste storage can be gained by studying the conditions of uranium ore deposit formation. Further information can be gained by comparing the chemistry of uranium to nuclear fission products and other radionuclides of concern to nuclear waste disposal. Redox state appears to be the most important variable in controlling uranium solubility, especially at near neutral pH, which is characteristic of most ground water. This is probably also true of neptunium… more
Date: February 1, 1982
Creator: Duffy, C.J. & Ogard, A.E.
Partner: UNT Libraries Government Documents Department
open access

DOE research and development report. Progress report, October 1980-September 1981

Description: The DOE New Brunswick Laboratory (NBL) is the US Government's Nuclear Materials Standards and Measurement Laboratory. NBL is assigned the mission to provide and maintain, as an essential part of federal statutory responsibilities related to national and international safeguards of nuclear materials for USA defense and energy programs, an ongoing capability for: the development, preparation, certification, and distribution of reference materials for the calibration and standardization of nu… more
Date: March 1, 1982
Creator: Bingham, Carleton D.
Partner: UNT Libraries Government Documents Department
open access

Geothermal data for 95 thermal and nonthermal waters of the Valles Caldera - southern Jemez Mountains region, New Mexico

Description: Field, chemical, and isotopic data for 95 thermal and nonthermal waters of the southern Jemez Mountains, New Mexico are presented. This region includes all thermal and mineral waters associated with Valles Caldera and many of those located near the Nacimiento Uplift, near San Ysidro. Waters of the region can be categorized into five general types: (1) surface and near surface meteoric waters; (2) acid-sulfate waters (Valles Caldera); (3) thermal meteoric waters (Valles Caldera); (4) deep geothe… more
Date: May 1, 1982
Creator: Goff, F.; McCormick, Trujillo, P.E. Jr.; Counce, D. & Grigsby, C.O.
Partner: UNT Libraries Government Documents Department
open access

Linear Accelerator for Radioisotope Production

Description: A 200- to 500-..mu..A source of 70- to 90-MeV protons would be a valuable asset to the nuclear medicine program. A linear accelerator (linac) can achieve this performance, and it can be extended to even higher energies and currents. Variable energy and current options are available. A 70-MeV linac is described, based on recent innovations in linear accelerator technology; it would be 27.3 m long and cost approx. $6 million. By operating the radio-frequency (rf) power system at a level necessary… more
Date: February 1, 1982
Creator: Hansborough, L. D.; Hamm, R. W. & Stovall, J. E.
Partner: UNT Libraries Government Documents Department
open access

Radiogenic gas accumulation in TRU waste storage drums

Description: A field experiment was conducted over a four-year time span to determine the effect of high-activity transuranic (TRU) waste on the atmosphere within TRU waste storage drums typical of those generated in Savannah River Plant operation. Routine gas composition analyses showed that a significant amount of hydrogen can accumulate in drums that contain high alpha activity, and that flammable gas mixtures could form in such drums in spite of the radiolytic consumption of oxygen. According to this st… more
Date: January 1, 1982
Creator: Ryan, J.P.
Partner: UNT Libraries Government Documents Department
open access

Effects of process severity on physiochemical properties of preasphaltenes

Description: This paper describes the physical character and reactions of preasphaltenes made from a bituminous coal. The preasphaltenes were obtained by reacting Illinois No. 6 Burning Star coal in contact with SRC-II heavy distillate under hydrogen pressure in an Autoclave for various times (10 to 30 minutes) and temperatures (350 to 450/sup 0/C). The preasphaltenes were separated by using conventional Soxhlet extraction techniques. The primary question addressed was: Are preashaltenes produced under one … more
Date: January 1, 1982
Creator: Lynch, A. W. & Thomas, M. G.
Partner: UNT Libraries Government Documents Department
open access

Summary outline of DOE geoscience and geoscience - related research

Description: The Office of Basic Energy Sciences (OBES) supports long-range, basic research in those areas of the geosciences which are relevant to the nation's energy needs. The objective of the Geoscience program is to develop a quantitative and predictive understanding of geological, geophysical and geochemical structures and processes in the solid earth and in solar-terrestrial relationships. This understanding is to assure an effective knowledge base for energy resource recognition, evaluation and util… more
Date: February 1, 1982
Partner: UNT Libraries Government Documents Department
open access

Cascades for hydrogen isotope separation using metal hydrides

Description: Designs are presented for continuous countercurrent hydrogen isotope separation cascades based on the use of metal hydrides. The cascades are made up of pressure swing adsorption (PSA) or temperature swing adsorption (TSA) stages. The designs were evolved from consideration of previously conducted studies of the separation performance of four types of PSA and TSA processes.
Date: January 1, 1982
Creator: Hill, F.B. & Grzetic, V.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen