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Smithsonian Microbeam Standards
No full textThis is a short history of the Smithsonian Microbeam Standards; their sources, selection, preparation, and analyses. Fifty-eight minerals, natural glasses, and synthetic samples have been characterized in the past 25 years. During that time, over 750 requests were received for approximately 11 000 individual samples. These reference samples are referred to as the Smithsonian Microbeam Standards
Decomposition of wavelength dispersive x-ray spectra
No full textLine shapes of atomic lines and soft x-ray emission bands measured with a wavelength dispersive spectrometer (WDS) with the Electron Probe Micro Analyzer (EPMA) are reviewed. Least square fitting to pseudo-Voigt profiles of the digitally measured spectra are used to account for the presence of non-diagram features (high and low energy satellites) and instrumental induced distortions. The effect of line width and relative intensities on the quality of fits is illustrated. Spectral distortions resulting from the presence of absorption edges within the analyzed wavelength region are illustrated for the case of FeLalpha,beta emission bands for pure Fe and iron oxides. For quantitative analysis, an analytical approach is presented where the measured soft x-ray emission bands are corrected for self absorption before extracting the intensities from the experimental data
Olga Taussky-Todd
No full textOLGA TAUSSKY-TODD
Inducted: 2002
Citation:
Technical Consultant, Applied Mathematics Division, 1947-1957
Tenure: 1947-1957
Birth: 1906, Olmütz, Moravia, (now Olomouc)
Death: 1995, Pasadena, California
Education:
University of Vienna, PhD (mathematics), 1930
Fellowships at Bryn Mawr, Cambridge (Girton College), and London
Position held:
Technical Consultant, Applied Mathematics Division, 1947-1957
Honors:
Woman of the Year, Los Angeles Times, 1963
Fulbright Professor, University of Vienna
Ford Prize, Mathematical Association of America
Gold Cross of Honor, Government of Austria
First woman to attain rank of full professor, California Institute of Technology
Honorary MA, Cambridge University
"Doctor of Science honoris causa," University of Southern California's, 1988
Memberships:
American Association for the Advancement of Science, Fellow
Austrian Academy of Science, Corresponding Member
Bavarian Academy of Science, Corresponding Member
American Mathematical Society, Member of the Council, Vice President
Council of the London Mathematical Society, Member
Publications:
A recurring theorem on determinants, American Mathematical Monthly (1949)
A remark concerning the characteristic roots of the finite segments of the Hilbert matrix, Oxford Quarterly Journal, (1949)
Commutativity in finite matrices, American Mathematical Monthly, (1952)
Some computational problems in algebraic number theory, in: Numerical Analysis, John H. Curtiss, ed, McGraw-Hill, New York, (1956)
Generation and testing of pseudo-random numbers (with J. Todd), Symposium on Monte Carlo Methods, University of Florida, (1954)
Some non-commutativity Methods in Algebraic Number Theory, in: A Century of Mathematics in America, Am. Math. Soc., (1988)
A History of Sums of Squares in Algebra, in American Mathematical Heritage, Texas Tech. University, (1981
Robert D. Stiehler
No full textROBERT D. STIEHLER
NBS: 1946 - 1981
Birth: July 16, 1910, Springfield, New York
Death: October 8, 2002
EDUCATION:
Rensselaer Polytechnic Institute, (chemistry), 1926-1929
Johns Hopkins University, PhD (chemistry), 1933
National Research Council Fellow, California Institute of Technology, 1933-34
Research Fellow in Ophthalmology, Johns Hopkins Medical School, 1934-38
PRINCIPAL FIELD:
Development of test methods for organic and fibrous materials
POSITIONS HELD AT NBS:
Research Chemist, Rubber Section
Chief, Testing and Specifications Section
Chief, Polymer Evaluation and Testing Section
HONORS:
U.S. Department of Commerce Silver Medal, 1963
American Society for Testing and Materials (ASTM); Award of Merit, 1968; Honorary Member, 1977
MEMBERSHIPS:
American Society for Testing and Materials, Honorary Member, 1977
ASTM Technical Committees, Member on Rubber, Textiles, Temperature Measurement, Metric Practice, Solar Energy, Consumer Products
American Association for the Advancement of Science, Fellow
American Chemical Society, Fellow
International Organization for Standardization Committee on Rubber
American Society of Mechanical Engineers, Emeritus Member
American Society for Quality, Emeritus Member
Institution of the Rubber Industry (London), former member
PUBLICATIONS:
Over 60 significant publications dealing with the testing and properties of materials
Co-authored (with John Mandel) several papers on the evaluation of analytical and test methods by the sensitivity criterion
Member of U.S. Metric Study; co-author of Volume I on International Standards, and author of Volume II on Engineering Standards, (1975)
Patent on tire teste
E. Dale West
No full textE. [Estal] Dale West
Inducted: 2002
Citation:
For his leadership in calorimetry studies, both theoretical and experimental, particularly in the development of isoperibol calorimetry, which led to the creation of national standards for laser energy measurements.
Tenure: 1948 – 1974
Birth: 1918, Ravenwood, Missouri
Death: 1992, Surprise, Arizona
Education:
George Washington University, Attended, 1940-1941
California Institute of Technology, ABS, (chemistry), 1949
University of Maryland, MS, (physical chemistry), 1958
University of Maryland, PhD., (physical chemistry), 1969
Positions Held:
Member, and later Chief, Heat Measurements Section, Heat Division, Washington and Gaithersburg, 1948 - 1969
Chief, Laser Power and Energy Section, Quantum Electronics Division, Boulder, 1969-1974
Honors:
Department of Commerce Silver Medal, 1969
Who’s Who in Science and Technology
Memberships:
Sigma Xi
Publications:
Numerous papers, reporting theoretical and experimental advances in the state-of-the-art of calorimetry and its application to the measurement of quantities as diverse as heats of reaction and solution, heat capacity, high-temperature enthalpy, the absorptance of optical energy, and laser power and energy. West’s seminal paper with Kenneth Churney, on the use of isoperibol calorimetry to measure laser energy, provided the theoretical foundation for a family of calorimeters that became U.S. national standards, and which provide a breadth and strength of laser measurement capability that is unmatched elsewhere. West led the experimental development of the first two of these standards. Others based on the theory followed, and continue to be developed. The West-Churney paper was recognized as being among the 100 most significant papers published by NBS/NIST during its first 100 years. Earlier, West published important papers on high-temperature calorimetry, including work that supported the development of Standard Reference Material 720, for enthalpy and heat capacity at temperatures between 10 K and 2250 K, which was released in 1970 and is still available. The paper describing SRM 720, published after West’s retirement, is definitive and frequently referenced.
Theory of Isoperibol Calorimetry for Laser Power and Energy Measurements, (with K. L. Churney), J. Appl. Phys. 41, (1970)
A Reference Calorimeter for Laser Energy Measurements, (with W. E. Case, A. L. Rasmussen, and L. B. Schmidt), J. Res. Natl. Bur Stand, 76A, (1972)
A System for Calibrating Laser Power Meters for the Range 5 - 1000 W, (with L. B. Schmidt), NBS Technical Note 685, National Bureau of Standards, Boulder, (1977
(Audio Part 3 of 4) SEAC oral history interview, September 18, 2002 / with Russell Kirsch, Ruth Cahn, Robert Elbourn, and Sidney Greenwald.
No full text
Contamination in the rare-earth element orthophosphate reference samples
No full textSeveral of the fourteen rare-earth element (plus Sc and Y) orthophosphate standards grown at Oak Ridge National Laboratory in the 1980s and widely distributed by the Smithsonian Institution's Department of Mineral Sciences, are significantly contaminated by Pb. The origin of this impurity is the Pb2P2O7 flux that is derived from the thermal decomposition of PbHPO4. The lead pyrophosphate flux is used to dissolve the oxide starting materials at elevated temperatures (approximate to 1360 degreesC) prior to the crystal synthesis. Because these rare-earth element standards are extremely stable under the electron beam and considered homogenous, they have been of enormous value to electron probe microanalysis (EPMA). The monoclinic, monazite structure, orthophosphates show a higher degree of Pb incorporation than the tetragonal xenotime structure, orthophosphates. This paper will attempt to describe and rationalize the extent of the Pb contamination in these otherwise excellent materials
Accurate cross sections for microanalysis
No full textTo calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a few elements. Results of systematic plane wave Born approximation calculations with exchange for K, L, and M shell ionization cross sections over the range of electron energies used in microanalysis are presented. Comparisons are made with experimental measurement for selected K shells and it is shown that the plane wave theory is not appropriate for overvoltages less than 2.5 V