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George T. Furukawa
No full textGEORGE T. FURUKAWA
Inducted: 2003
Citation:
For his wide-ranging studies in thermodynamics and thermometry, including high-precision measurements of temperature reference transitions, calorimetry, and the analysis of low-temperature thermodynamic properties.
Tenure: 1948 - 1985
Birth: 1921, Cupertino, California
Education:
Central College, Fayette, Missouri, 1943
University of Wisconsin, PhD (Physical Chemistry), 1948
Positions held:
Physicist/Chemist
Senior Researcher
Honors:
Department of Commerce: Silver Medal, 1973
American Society of Testing and Materials, Award of Merit, 1986
Memberships:
American Chemical Society
American Physical Society
American Society of Testing and Materials
Sigma Xi
Standards Alumni Association
Publications:
Author or coauthor of over 100 scientific reports, monographs, and journal publications related to thermodynamic data and thermometry, including:
“Heat Capacities” (with T.B. Douglas) in American Institute of Physics Handbook, McGraw-Hill, 1957, 1963, and 1972 editions.
Critical Analysis of the Heat-Capacity Data of the Literature and Evaluation of Thermodynamic Properties of Copper, Silver, and Gold from 0 to 300 K (with coauthors), NSRDS-NBS 18 (1968)
Platinum Resistance Thermometry (with coauthors), NBS Monograph 126 (1973)
Application of Some Metal SRM’s as Thermometric Fixed Points (with coauthors), NBS Special Publication 260-77 (1982)
“Effects of Different Methods of Preparation of Ice Mantles of Triple Point of Water Cells on the Temporal Behavior of the Triple-Point Temperatures,” (with coauthors), Metrologia, (1997)
“Investigation of the Non-Uniqueness of the ITS-90 in the Range 600 ºC to 962 ºC” (with G.F. Strouse), Proceedings of TEMPMEKO 2001, 2002
(Audio Part 1 of 3) Oral history interview of Ruth M. Davis, May 6, 2003/ with Lisa Greenhouse.
No full text(Audio Part 3 of 3) Oral history interview of Ruth M. Davis, May 6, 2003/ with Lisa Greenhouse.
No full textNew national air-kerma-strength standards for I-125 and Pd-103 brachytherapy seeds
No full textThe new U.S. measurement standard for the air-kerma strength from low-energy photon-emitting brachytherapy seed sources is formally described in detail. This instrument-based standard was implemented on 1 January 1999, with its salient features and the implications of differences with the previous standard given only through a series of informal communications. The Wide-Angle Free-Air Chamber (WAFAC) is specially designed to realize air kerma from a single-seed source emitting photons with energies up to about 40 keV, and is now used to measure the wide variety of seeds used in prostate-cancer therapy that has appeared in the last few years. For the two 125I seed models that have been subject to both the old and new standards, the new standard reduces the air-kerma strength by 10.3 %. This change is mainly due to the removal of the influence on the measurement of the Ti K x rays produced in the source encapsulation, a component with no clinical significance
Changes in the US primary standards for the air kerma from gamma-ray beams
No full textMonte Carlo photon-electron transport calculations have been done to derive new wall corrections for the six NBS-NIST standard graphite-wall, air-ionization cavity chambers that serve as the U.S. national primary standard for air kerma (and exposure) for gamma rays from Co-60, Cs-137, and Ir-192 sources. The data developed for and from these calculations have also been used to refine a number of other factors affecting the standards. The largest changes are due to the new wall corrections, and the total changes are +0.87% to +1.11% (depending on the chamber) for Co-60 beams, +0.64% to +1.07% (depending on the chamber) for Cs-137 beams, and -0.06% for the single chamber used in the measurement of the standardized Ir-192 source. The primary standards for air kerma will be adjusted in the near future to reflect the changes in factors described in this work
Statistical interpretation of key comparison reference value and degrees of equivalence
No full textKey comparisons carried out by the Consultative Committees (CCs) of the International Committee of Weights and Measures (CIPM) or the Bureau International des Poids et Mesures (BIPM) are referred to as CIPM key comparisons. The outputs of a statistical analysis of the data from a CIPM key comparison are the key comparison reference value, the degrees of equivalence, and their associated uncertainties. The BIPM publications do not discuss statistical interpretation of these outputs. We discuss their interpretation under the following three statistical models: nonexistent laboratory-effects model, random laboratory-effects model, and systematic laboratory-effects model
Uncertainties in interpolated spectral data
No full textInterpolation is often used to improve the accuracy of integrals over spectral data convolved with various response functions or power distributions. Formulae are developed for propagation of uncertainties through the interpolation process, specifically for Lagrangian interpolation increasing a regular data set by factors of 5 and 2, and for cubic-spline interpolation. The interpolated data are correlated; these correlations must be considered when combining the interpolated values, as in integration. Examples are given using a common spectral integral in photometry. Correlation coefficients are developed for Lagrangian interpolation where the input data are uncorrelated. It is demonstrated that in practical cases, uncertainties for the integral formed using interpolated data can be reliably estimated using the original data
A primary dead-weight tester for pressures (0.05-1.0) MPa
No full textRecent advances in technology on two fronts, 1) the fabrication of large-diameter pistons and cylinders with good geometry, and 2) the ability to measure the dimensions of these components with high accuracy, have allowed dead-weight testers at the National Institute of Standards and Technology (NIST) to generate pressures that approach total relative uncertainties previously obtained only by manometers. This paper describes a 35 mm diameter piston/cylinder assembly ( known within NIST as PG-39) that serves as a pressure standard in which both the piston and the cylinder have been accurately dimensioned by Physikalisch Technische Bundesanstalt (PTB). Both artifacts ( piston and cylinder) appeared to be round within +/- 30 nm and straight within +/- 100 nm over a substantial fraction of their heights. Based on the diameters at 20 degreesC provided by PTB (+/-15 nm) and on the good geometry of the artifact, the relative uncertainties for the effective area were estimated to be about 2.2 x 10(-6) (1sigma)
