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A small-volume apparatus for the measurement of phase equilibria
No full textAn apparatus has been designed and constructed for the measurement of vapor-liquid equilibrium properties. The main components of the apparatus consist of an equilibrium cell and a vapor circulation pump. The cell and all of the system valves are housed inside a temperature controlled, insulated aluminum block. The temperature range of the apparatus is 260 K to 380 K to pressures of 6 MPa. The uncertainty of the temperature measurement is 0.03 K, and the uncertainty in the pressure measurement is 9.8 x 10(-4) MPa. An automated data acquisition system is used to measure temperature and pressure at equilibrium. The apparatus has been performance tested by measuring the vapor pressures of propane, butane, and a standard mixture of propane + butane
Ambiguities in powder indexing: Conjunction of a ternary and binary lattice metric singularity in the cubic system
No full textA lattice metric singularity occurs when unit cells defining two (or more) lattices yield the identical set of unique calculated d-spacings. The existence of such singularities, therefore, has a practical and theoretical impact on the indexing of powder patterns. For example, in experimental practice an indexing program may find only the lower symmetry member of a singularity. Obviously, it is important to recognize such cases and know how to proceed. Recently, we described: (1) a binary singularity involving a monoclinic and a rhombohedral lattice in a subcell-supercell relationship and (2) a second type of singularity - a ternary singularity - in which two of the three lattices are in a derivative composite relationship. In this work, we describe a ternary lattice metric singularity involving a cubic P, a tetragonal P, and an orthorhombic C lattice. Furthermore, there is a binary singularity, involving a hexagonal P and orthorhombic P lattice, which is characterized by a set of unique d-spacings very close to that of the ternary singularity. The existence of such singularities is more common than once thought and requires a paradigm shift in experimental practice. In addition singularities provide opportunities in material design as they point to highly specialized lattices that may be associated with unusual physical properties
Intramural comparison of NIST laser and optical fiber power calibrations
No full textThe responsivity of two optical detectors was determined by the method of direct substitution in four different NIST measurement facilities. The measurements were intended to demonstrate the determination of absolute responsivity as provided by NIST calibration services at laser and optical-communication wavelengths; nominally 633 nm, 850 nm, 1060 nm, 1310 nm, and 1550 nm. The optical detectors have been designated as checks standards for the purpose of routine intramural comparison of our calibration services and to meet requirements of the NIST quality system, based on ISO 17025. The check standards are two optical-trap detectors, one based on silicon and the other on indium gallium arsenide photodiodes. The four measurement services are based on: (1) the laser optimized cryogenic radiometer (LOCR) and free field collimated laser light; (2) the C-series isoperibol calorimeter and free-field collimated laser light; (3) the electrically calibrated pyroelectric radiometer and fiber-coupled laser light; (4) the pyroelectric wedge trap detector, which measures light from a lamp source and mono-chromator. The results indicate that the responsivity of the check standards, as determined independently using the four services, agree to within the published expanded uncertainty ranging from approximately 0.02% to 1.24%
Bayesian inference of nanoparticle-broadened X-ray line profiles
No full textA single-step, self-contained method for determining the crystallite-size distribution and shape from experimental x-ray line profile data is presented. It is shown that the crystallite-size distribution can be determined without invoking a functional form for the size distribution, determining instead the size distribution with the least assumptions by applying the Bayesian/MaxEnt method. The Bayesian/MaxEnt method is tested using both simulated and experimental CeO2 data, the results comparing favourably with experimental CeO2 data from TEM measurements
Charles C. Han
No full textCHARLES C. HAN
NBS/NIST: 1974 - 2002
Birth: January 18, 1944 in Sichuan, China
Education:
National Taiwan University, BS (Chemical Engineering), 1966
University of Houston, MS (Physical Chemistry), 1969
University of Wisconsin, Madison, PhD, (Physical Chemistry), 1973
Principal Fields:
Polymer Physics, Physical Chemistry, Neutron, X-ray and Light Scattering, Polymer blends and alloys.
Positions held at NBS/NIST:
Research Scientist, Material Science and Engineering Laboratory 1974-2002
Group Leader, Polymer Blends Group, Material Science and Engineering Laboratory 1985-1995
Group Leader, Multiphase Materials Group, Material Science and Engineering Laboratory 1999-2002
NIST Fellow, 1995-2002
Honors:
Bronze Medal, Department of Commerce, 1980
Silver Medal, Department of Commerce, 1982
Dillon Medal, American Physical Society, 1984
Gold Medal, Department of Commerce, 1986
Samuel Wesley Stratton Award for Best Research, NIST, 1990
Humboldt Senior Research Award, Alexander von Humboldt Foundation, Germany, 1995
High Polymer Physics Prize, American Physical Society, Division of High Polymer Physics, 1999
Memberships:
American Physical Society (Fellow)
American Chemical Society
American Physical Society
Sigma Xi
Publications:
More than 280 Scientific Papers in Archived Journals and Books including 4 US Patents:
A. Z. Akcasu, M. Benmouna, and C. C. Han, "Interpretation of Dynamic Scattering from Polymer Solutions", Polymer, 21, 866 (1980).
T. Sato, and C. C. Han, "Dynamics of Concentration Fluctuation in a Polymer Blend on Both Sides of Phase Boundary", J. Chem. Phys., 88, 2057 (1988).
E. K. Hobbie, D. W. Hair, A. I. Nakatani and C. C. Han,"Crossover to Strong Shear in a Low Molecular Weight Critical Polymer Blend", Phys. Rev. Lett., 69, 1951 (1992).
M. Motowoka, H. Jinnai, T. Hashimoto, Y. Qiu, and C. C. Han, "Phase Separation in Deuterated Polycarbonate/Poly(methylmethacrylate) Blend Near Glass Transition Temperature, J Chem. Phys., 99, 2095 (1993)
George G. Harman
No full textGEORGE G. HARMAN
NBS/NIST: 1950 - 2003
Birth: December 7, 1924 Norfolk, Virginia
Education:
Virginia Polytechnic Institution, BS (Industrial Physics), 1949
University of Maryland, MS (Physics), 1959
Principal Fields:
Microwave instrumentation, semiconductor physics; semiconductor device interconnections; high temperature devices/interconnections; materials for advanced copper low-dielectric-constant semiconductor devices; electronic packaging.
Positions held at NBS/NIST:
Electronic Scientist, Electricity and Electronics Division
Research Physicist, Semiconductor Devices and Circuits Division
Project Leader, Physicist, Solid State, Electronic Technology Division
Senior Research Scientist, Electronic Technology Division
NIST Fellow and Dean of Staff, Semiconductor Electronics Division
NIST Scientist Emeritus, Semiconductor Electronics Division
Honors:
U. S. Dept. of Commerce, Silver Medal, 1973; Gold Medal, 1979.
National Institute of Standards and Technology, E. U. Condon Award, 1990.
Institute of Electrical and Electronics Engineers, Centennial Medal, 1984; CPMT David Feldman Award, 1992; ECTC Distinguished Contributions Award, 1993; Harry Diamond Memorial Award, 1996; Third Millennium Medal, 2000; CPMT Outstanding Sustained Technical Contributions Award, 2001; Chair, IEEE-CPMT Fellow Committee 1988-2002.
International Microelectronics and Packaging Society, Technical Achievement Award, 1981; Lewis F. Miller Award, 1984; Daniel C. Hughes Award, 1989; Education Foundation Distinguished Service Award, 1990, International President 1994-1995
EuPac-Fraunhofer Institute, IZM (Germany), First European (Electronic) Packaging Award, 1998
Society of Manufacturing Engineers, Total Excellence in Electronics Manufacturing Award, 2001
Memberships:
Institute of Electrical and Electronics Engineers (Life Fellow)
International Microelectronics and Packaging Society (Life Fellow)
Sigma Xi, Sigma Pi Sigma
ASTM International
American Physical Society
Publications:
Over 60 publications, plus eight book chapters, four patents, two NBS Special Publications 400-2.
Technical Note 573, two sole-author books, the last book is Wire Bonding in Microelectronics, Materials, Processes, and Yield, McGraw Hill, 1997
Initial NIST AC QHR measurements
No full textWe demonstrate that dc quantized Hall resistance (dc QHR) guideline properties and dc and ac QHR values can be measured without changing sample probe lead connections at the QHR device, and report ac QHR values that converge to the dc QHR value when using four-terminal-pair ac QHR measurements. This was accomplished during one cooldown using single-series and quadruple-series connections outside the sample probe. The QHR was measured from 0 Hz to 5500 Hz in 1: 1 ratio at 20 micro A to +/- 1 part in 10(7) uncertainties with a poor-quality QHR device. A good device would allow an order of magnitude smaller uncertainties over this frequency range. We exchanged positions of the QHR device and reference resistor in the bridge and remeasured the resistance ratios to remove dominant ac bridge effects
Electron-impact cross sections for ground state to np excitations of sodium and potassium
No full textCross sections for electron impact excitation of atoms are important for modeling of low temperature plasmas and gases. While there are many experimental and theoretical results for excitation to the first excited states, little information is available for excitation to higher states. We present here calculations of excitations from the ground state to the np levels of sodium (n = 3 through 11) and potassium (n = 4 through 12). We also present a calculation for a transition from the excited sodium level 3p to 3d to show the generality of the method. Scaling formulas developed earlier by Kim [Phys. Rev. A 64, 032713 (2001)] for plane-wave Born cross sections are used. These formulas have been shown to be remarkably accurate yet simple to use. We have used a core polarization potential in a Dirac-Fock wave function code to calculate target atom wave functions and a matching form of the dipole transition operator to calculate oscillator strengths and Born cross sections. The scaled Born results here for excitation to the first excited levels are in very good agreement with experimental and other theoretical data, and the results for excitation to the next few levels are in satisfactory agreement with the limited data available. The present results for excitation to the higher levels are believed to be the only data available
Preparation and comprehensive characterization of a calcium hydroxyapatite reference material
No full textNumerous biological and chemical studies involve the use of calcium hydroxyapatite (HA), Ca-10(PO4)(6)(OH)(2). In this study detailed physicochemical characterization of HA, prepared from an aqueous solution, was carried out employing different methods and techniques: chemical and thermal analyses, x-ray diffraction, infrared and Raman spectroscopies, scanning and transmission microscopies, and Brunauer, Emmett, and Teller (BET) surface-area method. The contents of calcium (Ca2+), phosphate (PO43-), hydroxide (OH-), hydrogenphosphate (HPO42-), water (H2O), carbonate (CO32-), and trace constituents, the Ca/P molar ratio, crystal size and morphology, surface area, unit-cell parameters, crystallinity, and solubility of this HA were determined. This highly pure, homogeneous, and highly crystalline HA is certified as a National Institute of Standards and Technology (NIST) standard reference material, SRM 2910
Peter L.M. Heydemann
No full textPETER L.M. HEYDEMANN
NBS/NIST: 1964-2001
Birth: 10 November 1928, Göttingen, Germany
Education:
University of Göttingen, Germany, PhD (Physics, Chemistry, and Physiology), 1958
Principal Fields:
Physics and chemistry of polymers, properties of the human auditory system, physical properties at high pressures, standards of pressure, measurement support for biotechnology, technical services for industry, standards in international trade.
Positions held at NBS/NIST:
Chief, Pressure and Vacuum Section
Program Analyst and Chief of the NBS Program Office
Director, Center for Chemical Physics
Associate Director for Programs, Budget, and Finance
Director, Center for Basic Standards
Deputy Director, Industrial Technology Services
Science Counselor, U.S. Embassy, New Delhi, India
Director, Technology Services
Honors:
U.S. Department of Commerce, Silver Medal 1977, Gold Medal, 1984
President’s Meritorious Executive Award, 1983
U.S. Department of State, Superior Service Award, 1993
Memberships:
American Physical Society
Commission on Thermodynamics IUPAC
American Society of Mechanical Engineers
American Physical Society
Publications:
P.L.M., Heydemann, “The Bi I-II Transition Pressure Measured with a Dead-Weight Piston Gage”, Journal of Applied Physics, 38, 2640-2644 (1967)
P.L.M. Heydemann, “Ultrasonic Measurements at Pressures up to 50 kbar”, Proceedings of the International Colloquium Les Proprietes Physiques des Solides sous Pression, Paris, France
P.L.M. Heydemann, “Determination and Correction of Quadrature Fringe Measurement Errors in Interferometers”, Applied Optics, Vol. 20
P.L.M. Heydemann, C. Tilford, W. Angel, “Ultrasonic Interferometer Manometers: 10 -5 torr Resolution”, Proceedings of the 22nd International Instrumentation Symposium (1976)
P.L.M. Heydemann, Editor, NIST International Activities, NIST Special Publications 915, July 199