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in subjects: "Microanalysis"

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Rapid, direct determination of organic sulfur in coal using electron-probe microanalysis

Electron probe microanalysis (EPM) for organic sulfur content can be performed easily on -20 to -100 mesh coal samples. Samples need only be mounted in epoxy and polished as coal samples are commonly prepared for petrographic examination. 15 areas within non-contiguous vitrinite grains are analyzed with the EPM. Without the need to produce a photomosaic, the organic sulfur content of vitrinite, and therefore of a coal, may be determined in less than 10 minutes. To test the EPM method coals were… more

Date: January 1, 1981

Creator: Raymond, R. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The role of carbon and temperature in determining electrical conductivity of basins, crust and mantle

Initial phase was concentrated on improving electron microprobe techniques for carbon mapping of polished sections. Experiments were carried out on the utility of Au/Pd, Cr, and Ag coats; results shows that Cr and Ag gave good results. Observations were made on maps of carbon distribution in rocks; low magnification base maps consisting of a mosaic of BSE images were produced on the SEM, and traverses were plotted. The metamorphic rocks adjacent to the Denali fault were chosen for study.

Date: January 1, 1992

Creator: Mathez, E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Electron Energy-Loss Spectroscopy: Fundamentals and applications in the characterization of minerals

The combined use of an energy-loss spectrometer and an analytical electron microscope with fine probe forming capabilities provides a wealth of information about the sample at high spatial resolution. Fundamental principles governing the physics of the interaction between the fast electron and a thin foil sample, to account for the fine structure in the inelastically scattered fast electron distribution (Electron-Energy Loss Spectroscopy, EELS), will be reviewed. General application of EELS is … more

Date: April 1, 1989

Creator: Krishnan, K.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Background fitting for electron energy-loss spectra

Microanalysis using electron energy loss spectroscopy is now well established. In order to assess true edge profiles and obtain integrated intensities of the inner shell ionization edges of interest, it is first necessary to subtract the background. Usually a simple inverse power law is used, but for some spectra this form does not fit well. An alternative form which results in superior fits is described.

Date: 1981~

Creator: Bentley, James; Lehman, G.L. & Sklad, P.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ultra-sensitive isotopic analysis by resonance ionization mass spectrometry

A high-powered pulsed dye laser has been interfaced to a commerical ion microprobe mass analyzer. This combination should provide ultra-high sensitivity for isotope ratio measurements of selected elements in environmental samples. The technique is an outgrowth of resonance ionization mass spectrometry which has demonstrated high precision for isotope ratio determinations of uranium and plutonium using thermal filament atomization. Sputter atomization using a pulsed argon ion beam represents a s… more

Date: January 1, 1984

Creator: Donohue, D. L.; Christie, W. H.; Goeringer, D. E. & McKown, H. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Physical and chemical characterization and comparison of solids, liquids, and oils derived from Estonian and Green River formation shales

Although only a single Estonian raw shale sample with an unknown history has been examined, physical and chemical characterization of this material has been accomplished. A comparison with a representative Green River formation raw shale has been made. Some of the findings are: (1) Elemental analysis indicates that the major elements, aluminum, magnesium, and sodium are deficient in Estonian shale compared to the Green River shale. The minor elements, barium and strontium, and the trace element… more

Date: January 1, 1981

Creator: Peterson, E. J. & Spall, W. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Array automated assembly task for the Low-Cost Silicon Solar Array Project, Phase 2. Sixth quarterly report

This program is concerned with nickel/solder metallization of silicon solar cells. Work in this second quarter of the program extension comprised portions of four experimental tasks. The task to study nickel plating on silicon oxide films has led to the finding that the plating solution dissolves oxide before depositing nickel. The electron microprobe study of nickel penetration of silicon has shown that sintering can be conducted for long times at 300/sup 0/C but that problems may arise above … more

Date: April 1, 1980

Creator: Petersen, R. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

User oriented software system for electron microprobes

A user-oriented software system for electron microprobes is described. The TASK automation program which provides instrument control and data collection is also capable of calling auxiliary programs which can provide quantitative data reduction, editing, plotting, summary, and statistical analysis capabilities. Qualitative analysis auxiliary capabilities include digital electronic scanning of the beam, mechanical scanning of the stage and the wavelength dispersive (WDS) spectrometers, identific… more

Date: January 1, 1979

Creator: Chambers, W.F. & Doyle, J.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Abstracts for new opportunities in chemistry: An international symposium on the uses of synchrotron radiation in chemistry, November 4-6, 1987

Seventy-eight summaries of presentations are included. (DLC)

Date: January 1, 1987

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Study of the Effect of Reactive Element Addition by Implanting Metal Ions in a Pre-Formed Oxide Layer

The influence of ion-implanted Y, Hf, Zr and Cr on the oxidation behavior of a Ni-25 wt % CR alloy at 1000{degrees}C has been investigated. The implantation dosage was 5 {times} 10{sup 16} ions/cm{sup 2}. Two methods of implantation have been used. One was to implant ions directly into a clean alloy surface; the other was to implant into an approximately 0.6 {mu}m thick Cr{sub 2}O{sub 3} layer formed at 1000{degrees}C on the alloy. In neither case did the Cr implantation show any beneficial eff… more

Date: September 1, 1990

Creator: Hou, P. Y.; Brown, I. G. & Stringer, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

X-ray microprobe studies of Hungarian background and urban aerosols

In order to determine the polluting atmospheric sources in urban and background areas source apportionment of the air particulate matter is necessary. Hitherto these studies were mostly based on bulk composition measurements of the aerosol. Source profiles, i.e. the concentrations of several elements for air particulate matter originating from one source, can be deduced from the receptor data using a number of multivariate techniques among which the chemical mass balance. The application is lim… more

Date: October 1, 1991

Creator: Toeroek, S.; Sandor, S.; Xhoffer, C.; Van Grieken, R.; Jones, K. W.; Sutton, S. R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Micro-tomography using synchrotron radiation

This paper discusses the results of recent experiments at Stanford Synchrotron Radiation Laboratory (SSRL) and Hamburger Synchrotronstrahlungslabor (HASYLAB) which were designed to explore the feasibility of using synchrotron radiation in high-resolution, computerized, critical-absorption tomography. The results demonstrate that it is possible, using absorption-edge differencing, to identify adjacent elements in the periodic table with high sensitivity. Furthermore, by using the fine structure … more

Date: April 9, 1986

Creator: Johnson, Q.C.; Kinney, J.H.; Bonse, U.; Nichols, M.C.; Nusshardt, R. & Brase, J.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

SYNROC C: preparation and radwaste distribution

Results of the synthesis of SYNROC C from both high surface area (16m/sup 2//g) and low surface area (4m/sup 2//g) powders at low and high oxygen fugacities indicate variations in radionuclide distribution. These results are most striking for the partitioning of uranium between perovskite and zirconolite. In highly active powders, the formation of a pyrochlore precursor ensures that equilibrium partitioning is approached. In less active powders, no low temperature pyrochlore is formed. As a res… more

Date: October 16, 1981

Creator: Ryerson, F. J.; Hoenig, C. L. & Smith, G. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Analytical Chemistry Division. Annual progress report for period ending December 31, 1978

Research progress is reported on analytical methodology, mass and emission spectrometry, analytical services, bio-organic analysis, and nuclear and radiochemical analysis.

Date: May 1, 1979

Creator: Lyon, W.S. (ed.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Analytical transmission electron microscopy in materials science

Microcharacterization of materials on a scale of less than 10 nm has been afforded by recent advances in analytical transmission electron microscopy. The factors limiting accurate analysis at the limit of spatial resolution for the case of a combination of scanning transmission electron microscopy and energy dispersive x-ray spectroscopy are examined in this paper.

Date: January 1, 1980

Creator: Fraser, H.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Directory of Analytical Methods, Department 1820

The Materials Characterization Department performs chemical, physical, and thermophysical analyses in support of programs throughout the Laboratories. The department has a wide variety of techniques and instruments staffed by experienced personnel available for these analyses, and we strive to maintain near state-of-the-art technology by continued updates. We have prepared this Directory of Analytical Methods in order to acquaint you with our capabilities and to help you identify personnel who … more

Date: January 1, 1986

Creator: Whan, R.E. (ed.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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SEM and x-ray microanalysis of cellular differentiation in Sea Urchin Embryos: a frozen hydrated study

Quantitative studies of major chemical element distribution among individual differentiating cells were attempted using scanning electron microscopy. Frozen hydrated embryos of the sea urchin Strongelocentrotus purpuratus were examined at three stages: blastula, mesenchyme blastula, and early gastrula. The blastocoel matrix contained large beads of approximately 1 ..mu..m diameter. The cells of the archenteron lacked well defined cell boundaries. Characteristic levels of beam damage and chargin… more

Date: December 1, 1985

Creator: Klein, S.B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Phase formation at bonded vanadium and stainless steel interfaces

The interface between vanadium bonded to stainless steel was studies to determine whether a brittle phase formed during three joining operations. Inertia friction welds between V and 21-6-9 stainless steel were examined using TEM. In the as-welded condition, a continuous, polygranular intermetallic layer about 0.25 {mu}m thick was present at the interface. This layer grew to about 50 {mu}m thick during heat treatment at 1000{degrees}C for two hours. Analysis of electron diffraction patterns con… more

Date: January 1, 1992

Creator: Summers, T.S.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Analyses of SRS waste glass buried in granite in Sweden and salt in the United States

Simulated Savannah River Site (SRS) waste glass forms have been buried in the granite geology of the Stirpa mine in Sweden for two years. Analyses of glass surfaces provided a measure of the performance of the waste glasses as a function of time. Similar SRS waste glass compositions have also been buried in salt at the WIPP facility in Carlsbad, New Mexico for a similar time period. Analyses of the SRS waste glasses buried in-situ in granite will be presented and compared to the performance of … more

Date: January 1, 1991

Creator: Williams, J.P. (Tuskegee Inst., AL (United States)); Wicks, G.G. (Westinghouse Savannah River Co., Aiken, SC (United States)); Clark, D.E. (Florida Univ., Gainesville, FL (United States)) & Lodding, A.R. (Chalmers Tekniska Hoegskola, Goeteborg (Sweden))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pulsed CO/sub 2/ laser annealing of ion-implanted silicon

From studies of time-resolved reflectivity and microstructural changes, we have obtained direct evidence of CO/sub 2/ laser-induced melting above a threshold energy density. Results of the optical measurements, transmission electron microscopy, and secondary ion mass spectrometry are reported. The measurements show that melt depths as deep as 1 ..mu..m can be achieved with pulsed CO/sub 2/ laser radiation. By using differential absorption between layers with different free-carrier densities, we… more

Date: November 1, 1984

Creator: James, R. B.; Narayan, J.; Christie, W. H.; Eby, R. E.; Holland, O. W. & Wood, R. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurements of ionization cross-section for electron energy-loss microanalysis under well defined scattering conditions

Partial cross-sections required for electron energy-loss microanalysis have been measured for a series of high purity single crystal standards. For each sample four different scattering geometries were used. The experimental data were compared with theoretical calculations using both standard hydrogenic model and parametrized Hartree-Slater cross-sections. Best agreement between theory and experiment were observed for experiments performed in diffraction mode (image coupling) with the probe con… more

Date: April 1, 1991

Creator: Krishnan, K.M. & Echer, C.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Wire chamber degradation at the Argonne ZGS

Experience with multiwire proportional chambers at high rates at the Argonne Zero Gradient Synchrotron is described. A buildup of silicon on the sense wires was observed where the beam passed through the chamber. Analysis of the chamber gas indicated that the density of silicon was probably less than 10 ppM.

Date: January 1, 1986

Creator: Haberichter, W. & Spinka, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Microanalysis by electron energy loss spectroscopy at 300kV

Some features of the anticipated improvements in microanalysis by electron energy loss spectroscopy (EELS) at 300 kV compared to opeation at 100kV have been studied with the use of a Philips EM430T equipped with Gatan 607 EELS and EDAX 9100/70 systems. Detailed measurements have been made on a range of specimens, with emphasis on boron nitride and silicon carbide.

Date: January 1, 1986

Creator: Bentley, J. & Angelini, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

SIMS study of compositional changes observed in a PuO/sub 2/ heat source cladding alloy

Secondary ion mass spectrometry (SIMS) has been used to investigate changes that occur in an advanced Ir-0.3W alloy during high temperature aging. This alloy is used to clad /sup 238/PuO/sub 2/ heat sources used in thermoelectric generators for deep space reconnaissance satellites. Long-term direct contact with PuO/sub 2/ at 1400/sup 0/C leads to physical and chemical changes within the cladding alloy that affect its metallurgical properties. SIMS was used to show that Cr, Fe, Ni, and in some c… more

Date: January 1, 1983

Creator: Christie, W. H.; Taylor, D. H.; Eby, R. E. & Pavone, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department