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Oral history interview of John (Jack) Wachtman, February 4, 2010 / with David Lide, Edwin Fuller, Sheldon Wiederhorn and Hans Oser
No full textOral history interview of Dr. John Wachtman, who had an active career in the Material Science area of the NBS, the predecessor of NIST. Dr. Wachtman first joined NBS as a bench scientist. Dr. Wachtman spent thirty-two years at NIST starting in 1951
Ray Radebaugh
No full textRAY RADEBAUGH
Inducted: 2010
Citation:
For outstanding, pioneering contributions to cryocooler technologies, leadership in cryogenics research at NIST, and leadership in the national and international cryogenics community.
Tenure: 1966-2009
Birth: 1939, South Bend, Indiana
Education:
University of Michigan, BS (Engineering Physics), 1962
Purdue University, MS (Physics), 1965
Purdue University, PhD (Physics), 1966
Positions held:
Post-Doctoral Fellow, Cryogenics Division, Institute for Material Science (Boulder), 1966-1968
Research Physicist and Project Leader, Cryogenics Div., Thermophysical Properties Div., Chem. Sci. Eng. Div., Chemical Engineering Division, Thermophysics Division (Boulder), 1968-1995
Group Leader, Cryogenic Technologies Group, Physical and Chemical Properties Division (Boulder), 1995-2009
NIST Fellow, Thermophysical Properties Division, 838, CSTL (Boulder), 2009-Present
Honors:
R&D100 Award, Coolahoop Cryogenic Refrigerator (1990)
J&E Hall Gold Medal, Institute of Refrigeration (London) (1999)
US Department of Commerce Silver Medal (1995) and Gold Medal (2003)
Jacob Rabinow Applied Research Award, NIST (2001)
Robert W. Vance Award, Cryogenic Society of America (2001) and Lifetime Membership Award (2006)
Samuel C. Collins Award, Cryogenic Engineering Conference, Outstanding Contribution to Cryogenic Technology (2009)
Memberships:
Cryogenic Society of America
Publications:
More than 170 publications including:
Radebaugh, R., Thermodynamic Properties of He3-He4 Solutions with Applications to the He3-He4 Dilution Refrigerator, NBS Technical Note 362 (1967)
Marquardt, E. D., Radebaugh, R., and Dobak, J., “A Cryogenic Catheter for Treating Heart Arrhythmia”, Adv. Cryogenic Eng. 43, 903-910 (1998)
Radebaugh, R., “Pulse Tube Oxygen Liquefier”, Adv. Cryogenic Eng. 45, 457-464 (2000)
Patents on Acoustic Cryocooler, Miniature Mixed Gas Refrigeration System, Flexible Catheter Cryosurgical System, Cryogenic Heat Exchanger, and Mixed Gas Refrigeration
Radebaugh, R., “Refrigeration for Superconductors,” Proc. IEEE, Special Issue on Applications of Superconductivity 92, 1719-1734 (2004)
Radebaugh, R., “Cryocoolers: The state of the Art and Recent Developments,” J. Phys.: Condens. Matter 21, 164219 (2009
James F. Schooley
No full textJames F. Schooley
Inducted: 2010
Citation: For outstanding technical contributions and exceptional leadership as a pre-eminent research scientist and leader for NBS/NIST both in the laboratory and at the Division Chief level. His research work in temperature helped form the basis for International Temperature Scale of 1990 and his leadership activities helped make NBS/NIST a leader in temperature-based metrology.
Tenure: 1960-1990
Birth: 1931, Auburn, Indiana
Education:
Indiana University, AB (Chemistry), 1953
UC/Berkeley, MS (Nuclear Chemistry), 1955
UC/Berkeley, PhD (Nuclear Chemistry), 1961
Positions held:
NRC/NBS Postdoctoral Appointment, Division 3 Heat, 1960
Research Scientist, Low-Temperature Physics, Heat Division, IBS, 1961-1967
Chief, Cryogenic Physics Section, Heat Division, IBS, 1967-1973
Chief, Temperature Section, Heat Division, IBS, 1973-1977
Chief, Temperature Measurements and Standards Division, Center for Absolute Physical Quantities, 1977-1982
Research Scientist, Temperature and Pressure Measurements and Standards Division, Center for Absolute Physical Quantities, 1982-1990
Honors:
US Department of Commerce Silver Medal (1968) and Gold Medal (1979)
Program Chair and Editor-in-Chief international conference on �Temperature, Its Measurement and Control and Science and Industry� (1982 and 1992)
Memberships:
American Physical Society
Instrument Society of America
Washington Philosophical Society, Phi Beta Kappa
Sigma Xi Scientific Research Society
Publications:
More than 100 publications including:
Schooley, J.F., Hosler, W.R., and Cohen, M.L., “Superconductivity in Semiconducting SrTiO3”, Phys. Rev. Letters, Vol 12, 474 (1964)
Schooley, J.F., Soulen, R.J., Jr., and Evans, G.A., Jr., Preparation and Use of Superconductive Fixed Point Devices, SRM 767, NBS SP 260-44 (1972)
Schooley, J.F., Thermometry, CRC Press (1986)
Edsinger, L.A. and Schooley, J.F., “Differences Between Thermodynamic Temperature and t (IPTS-68) in the Range 230 degrees C to 660 degrees C,” Metrologia 26, pp. 95-106 (1989)
Schooley, J.F., Ed.-in-Chief, Temperature, Its Measurement and Control in Science and Industry, Vol. 6, AIP (1992)
Schooley, J.F., Responding to National Needs: The National Bureau of Standards Becomes the National Institute of Standards and Technology: 1969-1993, NIST SP955 (2000
Cornelius Lanczos
No full textCORNELIUS LANCZOS
Inducted: 2010
Citation:
For exceptional contributions to the numerical solution to eigenvalue problems of wide impact in computational physics and engineering
Tenure: 1943-44 and 1949-1952
Birth: 1893, Székesfehérvár, Hungary
Death: 1974
Education:
University of Budapest, Hungary, BA (Mathematics, Physics, and Philosophy), 1915
University of Szeged, Hungary, PhD (Mathematics and Physics), 1921
Positions held:
Staff Member, Mathematical Tables Project, National Applied Mathematics Laboratory, 1943-1944
Senior Researcher, NBS Institute for Numerical Analysis, National Applied Mathematics Laboratory, 1949-1952
Honors:
Scientific Assistant to Albert Einstein (1928-29)
Walker-Ames Lecturer, University of Washington (1947)
Chauvenet Prize, Mathematical Association of America (1960)
ScD, Trinity College, Dublin, Ireland (1962), National University of Ireland (1970), University of Lancaster,
England (1972), University of Frankfurt am Main (1972)
Memberships:
Royal Irish Academy (1958)
Honorary Member, Roland Eötvös Physical Society, Budapest, Hungary (1973)
Publications:
More than 150 publications including:
Lanczos, C., The Variational Principles of Mechanics, University of Toronto Press, [962] (1949)
Lanczos, C., “An Iteration Method for the Solution of the Eigenvalue Problem of Linear Differential and Integral Operators,” J. Res. Natl. Bur. Stand. 45, 255-282 [1699] (1950)
Rosser, J.B., Lanczos, C., Hestenes M.R., and Karush, W., Separation of Close Eigenvalues of a Real Symmetric Matrix, J. Res. Natl. Bur. Stand. 47, 291-297 [11] (1951)
Lanczos, C., Solution of Systems of Linear Equations by Minimized Iterations, J. Res. Natl. Bur. Stand. 49, 33-52 [390] (1952)
Lanczos, C., Tables of Chebyshev Polynomials Sn(x) and Cn(x), NBS Applied Mathematics Series 9, US Government Printing Office, [15] (1952)
Davis, W.R., ed., Cornelius Lanczos, Collected Published Papers with Commentaries, in six volumes, North Carolina State University (1998
(Audio Part 3 of 3) Oral history interview of John (Jack) Wachtman, February 4, 2010 / with David Lide, Edwin Fuller, Sheldon Wiederhorn and Hans Oser
No full textOral history interview of Dr. John Wachtman, who had an active career in the Material Science area of the NBS, the predecessor of NIST. Dr. Wachtman first joined NBS as a bench scientist. Dr. Wachtman spent thirty-two years at NIST starting in 1951
Precision and accuracy in scientific imaging
No full textDigital images are commonly used to represent scientific data. Typically, high resolution images with many square pixels are considered to be necessary under the assumption that the increased precision of such images yields increased accuracy to the viewer. We question this assumption by demonstrating improved accuracy in viewing digital images without requiring increased resolution by demonstrating how pixels with variable shapes chosen to best represent an image constitute a significant improvement over the square pixels in enhancing the accuracy of viewing such digital images
Preparation and properties of nanoparticles of calcium phosphates with various Ca/P ratios
No full textThis study aimed at preparing and studying the properties of nanoparticles of calcium phosphate (nCaP) with Ca/P ratios ranging from 1.0 to 1.67 using a spray-drying technique. Micro-structural analyses suggested that the nCaPs with Ca/P ratios of 1.67 to 1.33 were nano-sized amorphous calcium phosphate (ACP) containing varying amounts of acid phosphate and carbonate. The nCaP with Ca/P ratio of 1 contained only nano-sized low crystalline dicalcium phosphate (DCP). BET measurements of the nCaPs showed specific surface areas of (12 +/- 2 to 50 +/- 1) m(2)/g, corresponding to estimated equivalent spherical diameters of (38 to 172) nm. However, dynamic light scattering measurements revealed much larger particles of (380 +/- 49 to 768 +/- 111) nm, owing to agglomeration of the smaller primary nano particles as revealed by Scanning Electron Microscopy (SEM). Thermodynamic solubility measurements showed that the nCaPs with Ca/P ratio of 1.33 - 1.67 all have similar solubility behavior. The materials were more soluble than the crystalline hydroxyapatite (HA) at pH greater than about 4.7, and more soluble than beta-tricalcium phosphate (beta-TCP), octacalcium phosphate (OCP) and DCP at pH above 5.5. Their solubility approached that of a-tricalcium phosphate (alpha-TCP) at about pH 7. These nCaPs, which cannot be readily prepared by other currently available methods for nanoparticle preparation, have potential biomedical applications
Measuring scale errors in a laser tracker's horizontal angle encoder through simple length measurement and two-face system tests
No full textWe describe a method to estimate the scale errors in the horizontal angle encoder of a laser tracker in this paper. The method does not require expensive instrumentation such as a rotary stage or even a calibrated artifact. An uncalibrated but stable length is realized between two targets mounted on stands that are at tracker height. The tracker measures the distance between these two targets from different azimuthal positions (say, in intervals of 20 degrees over 360 degrees). Each target is measured in both front face and back face. Low order harmonic scale errors can be estimated from this data and may then be used to correct the encoder's error map to improve the tracker's angle measurement accuracy. We have demonstrated this for the second order harmonic in this paper. It is important to compensate for even order harmonics as their influence cannot be removed by averaging front face and back face measurements whereas odd orders can be removed by averaging. We tested six trackers from three different manufacturers. Two of those trackers are newer models introduced at the time of writing of this paper. For older trackers from two manufacturers, the length errors in a 7.75 m horizontal length placed 7 m away from a tracker were of the order of +/- 65 mu m before correcting the error map. They reduced to less than +/- 25 mu m after correcting the error map for second order scale errors. Newer trackers from the same manufacturers did not show this error. An older tracker from a third manufacturer also did not show this error
Diffusion of ions between two solutions saturated with respect to hydroxyapatite: A possible mechanism for subsurface demineralization of teeth
No full textDiffusion-controlled dissolution and precipitation reactions occur in many biological systems and some non-stirred in vitro systems. Previous studies have shown that differences in the diffusion rates of the ions involved in a dissolution/precipitation reaction can produce significant effects on the rate and course of the reaction. We report here results of a study that show inter-diffusion of ions between two solutions, both saturated with respect to hydroxyapatite but with dissimilar compositions, resulted in one solution becoming undersaturated and the other supersaturated. A model is proposed that may explain the formation of a mineral-dense layer in the caries process
Properties of injectable apatite-forming premixed cements
No full textPrevious studies reported premixed calcium phosphate cements (CPCs) that were stable in the package and form hydroxyapatite (HA) as the product after exposure to an aqueous environment. These cements had setting times of greater than 60 min, which are too long to be useful for some clinical applications. The present study investigated properties of fast-setting HA-forming premixed CPCs that initially consisted of two separate premixed pastes: (1) finely ground (1.0 micrometers in median size) dicalcium phosphate anhydrous (DCPA) mixed with an aqueous NaH2PO4 solution, 1.5 mol/L or 3.0 mol/L in concentration, and (2) tetracalcium phosphate consisting of combinations of particles of two different size distributions, 5 micrometers (TTCP5) and 17 micrometers (TTCP17) in median size, mixed with glycerin. Equal volume of Pastes 1 and 2 were injected with the use of atwo-barrel syringe fitted with a static mixer into sample molds. The molar Ca/P ratio of combined paste was approximately 1.5. Cements were characterized in terms of setting time (Gilmore needle), diametral tensile strength (DTS), and phase composition (powder x-ray diffraction, XRD). Setting times were found to range from (4.3 +/- 0.6 to 68 +/- 3) min (mean +/- sd; n = 3), and 1-d and 7-d DTS values were from (0.89 +/- 0.08 to 2.44 +/- 0.16) MPa (mean +/- sd; n = 5). Both the NaH2PO4 concentration and TTCP particle size distribution had significant (p < 0.01) effects on setting time and DTS. Powder XRD analysis showed that low crystallinity HA and unreacted DCPA were present in the 1-day specimens, and the extent of HA formation increased with increasing amount of TTCP5 in the TTCP paste. Conclusion: Injectable HA-forming premixed CPCs with setting times from 4 to 70 min can be prepared by using DCPA and TTCP as the ingredients. Compared to the conventional powder liquid cements, these premixed CPCs have the advantages of being easy to use and having a range of hardening times