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James E. Hill
No full textJames E. Hill
Inducted: 2008
Citation: For extraordinary leadership in developing and implementing a wide range of NIST programs, including those on energy conservation in buildings and on solar energy, and in reducing global barriers to trade through promoting the role of standardization.
Tenure: 1972-2007
Birth: 1942, Bluefield, West Virginia
Education:
Virginia Polytechnic University, BS (Mechanical Engineering), 1963
Georgia Institute of Technology, MS (Mechanical Engineering), 1966
Georgia Institute of Technology, PhD (Mechanical Engineering), 1967
Positions held:
Mechanical Engineer, Thermal Engineering, Center for Building Technology, 1972-1978
Leader, Thermal Solar Group, Center for Building Technology, 1978-1980
Chief, Building Equipment Division, Center for Building Technology, 1980-1983
Program Analyst, Office of the Director, 1983-1984
Chief, Building Environment Division, Building and Fire Research Laboratory, 1984-1999
Deputy Director, Building and Fire Research Laboratory, 1999-2003
Acting Director, Building and Fire Research Laboratory, 2003-2004
Director, Building and Fire Research Laboratory, 2004-2006
Acting Deputy Director, NIST, 2006-2007
Honors:
Ronald H. Brown Standards Leadership Award (2007)
Meritorious Executive, Senior Executive Service (1988 and 1998)
Distinguished Service Award, ASHRAE (1995) and Crosby Field Award, ASHRAE (1975)
US Department of Commerce, Silver Medal (1976) and Gold Medal (1994)
Federal Engineer of the Year (1994)
ASHRAE Fellow (1992)
Memberships:
American Society of Heating, Refrigerants, and Air Conditioning Engineers (ASHRAE)
President, ASHRAE (1996-1997)
International Council for Research and Innovation in Building and Construction (CIB)
Vice-President, CIB (2003-2006)
Publications:
More than 65 Publications including:
Hill, J.E. and E.R. Streed, ‘A Method of Testing for Rating Solar Collectors Based on Thermal Performance,’ Solar Energy, Vol. 18, pp. 421-429, (1976)
Hill, J.E., Richtmyer, T.E., and J.P. Jenkins, ‘Initial Test Results for a Solar Cooled Townhouse in the Mid-Atlantic Region,’ ASHRAE Transactions, Vol82, (1976)
Jenkins, J.P. and Hill, J.E., ‘A Comparison of Test Results for Flat-Plate Water-Heating Solar Collectors Using the BSE and ASHRAE Procedures,’ Journal of Solar Energy Engineering, Vol. 102, pp. 2-15, (1980)
Hill, J.E. and A.H. Fanney, ‘A Proposed Procedure of Testing for Rating Solar Domestic Hot Water Systems,’ ASHRAE Transactions, Vol. 86, Part 1, pp. 805-822, (1980
Modeling of Photochemical Reactions in a Focused Laser Beam, II
No full textA method is described for obtaining the rate constant of the photodegradation process of fluorophores illuminated by a focused laser beam. The explicit kinetic equations, describing the population dynamics of excited singlet and triplet states, are averaged over the illuminated volume to describe the resulting fluorescence signal. The illumination is modulated at frequencies from 1 Hz to 100 Hz. Synchronous detection of the resulting fluorescence yields in-phase and quadrature components. The measurement of the ratio of quadrature to in-phase components at several power levels yields information on the photodegradation rate. Specifically it is shown that the data can be interpreted in a manner which yields the value of the photodegradation rate independently of other parameters entering the model. Experiments are performed with erythrosine B which has a large intersystem crossing rate to the triplet state. Measurements in solutions with different viscosities show that the photodegradation rate depends on the viscosity. This is interpreted as evidence for an intermolecular interaction mechanism. We explore the uncertainty of the estimated photodegradation constant taking into account the uncertainties of the measurements used in the synchronous detection technique
Fingerprint Scanner Angle Manipulation Device
No full textThe Fingerprint Scanner Angle Manipulation Device is a tool designed by the National Institute of Standards and Technology (NIST) in 2008 to test the usability of U.S. Department of Homeland Security fingerprint scanners when placed at various angles. The NIST test device shown is a hinged plastic stand and wood cylinders that allowed a fingerprint scanner to be set at one of the four angles being tested. The device is shown here with a foam mock-up of a fingerprint scanner. \n\n In 2008 the U.S. Department of Homeland Security's United States Visitor and Immigration Status Indicator Technology (US-VISIT) program was preparing to transition U.S. port of entry identity technology from a two-fingerprint capture process to a ten-fingerprint slap capture process. In preparing for the ten-fingerprint pilot testing, there was concern that the existing counter tops that housed the fingerprint scanners were too tall to support the ten-fingerprint collection process. Lowering the counter tops at US-VISIT facilities was not possible, but the fingerprint scanners could be angled on the counters. US-VISIT asked the NIST Biometrics Usability team, part of the NIST Information Technology Laboratory, to examine the impact on fingerprint capture performance when angling the fingerprint scanners at the existing counter heights. The NIST Biometrics Usability team’s study was specifically designed to determine what was the “best” angle to position the fingerprint scanner for efficiency in the time required to complete the task, the effectiveness in obtaining usable prints, and user comfort. The angles to test were first chosen by computer-aided design (CAD) modeling with a 95th percentile male model and a 5th percentile female model (this covers over 90% of the U.S. population). The Fingerprint Scanner Angle Manipulation Device was designed and built at NIST to enable the setting of four angles: 0 degrees, 10 degrees, 20 degrees, and 30 degrees. NIST collected data at all four angles (counterbalanced to control for ordering effects) regarding speed, quality, and user satisfaction with the fingerprinting process. NIST's analysis showed that an angle of 20 degrees was the best overall angle to position the fingerprint scanner. The Department of Homeland Security adopted NIST's guidance and have placed all fingerprint scanners at 20 degree angles at each point of entry to the United States, as well as at consulates and embassies. This angling of the scanners impacts 350,000 visitors entering the U.S. every day, and results in better user experience.[H]19.30 cm __[W]22.86 cm __[D]30.48 c
Richard E. Harris
No full textRichard E. Harris
Inducted: 2008
Citation: For the inspired and creative leadership that built both the Boulder Microelectronics Fabrication Facility and the research group that leads the world in superconducting quantum-based measurement and standards systems.
Tenure: 1975-2006
Birth: 1941, Kansas City, Missouri
Education:
University of Rochester, BS (Physics), 1963
University of Illinois, MS (Physics), 1965
University of Illinois, PhD (Physics), 1969
Positions held:
Physicist, Cryoelectronics Section (Boulder), 1975-1982
Group Leader, Cryoelectronic Metrology Group (Boulder), 1982-1993
Division Chief, Electromagnetic Technology Division (Boulder), 1993-2003
Group Leader, Quantum Devices Group (Boulder), 2003-2004
Chief Scientist, Quantum Electrical Metrology Division (Boulder), 2004-2006
Scientist Emeritus, Quantum Devices Group (Boulder), 2006 -
Honors:
US Department of Commerce Silver Medal (1980) and Gold Medal (1989)
Assigned by NIST for one year to IBM Research, Zurich, Switzerland. (1980)
Scientific Advisory Committee for Congress member David Skaggs (1988 – 1992)
Founding member, International Superconductivity Electronics Conference
Co-founder, US Workshop on Superconductive Circuits, Devices and Systems
Review committee for JTEC Study of Superconductivity Research in Japan, National Science Foundation (1989) and appeared on NOVA by the Public Broadcast System
Sigma Xi, elected 1969
Phi Beta Kappa, elected 1962
Memberships:
Elected Board Member, Applied Superconductivity Conference, 1984 – 1990
American Physical Society
Institute of Electronic and Electrical Engineers (senior member)
American Association for the Advancement of Science
Publications:
More than 25 publications and one patent, including:
Lloyd, F. L., Hamilton, C. A., Beall, J. A., Go, D., Ono, R. H., and Harris, R. E., “A Josephson Array Standard at 10 volts,” IEEE Elect. Dev. Letters, EDL-8, 449-450 (1987)
Harris, R. E., Hamilton, C.A., and Lloyd, F. L., “Multiple-quantum Interference Superconducting Analog-to-Digital Converter,” Appl. Phys. Letters 35, 720 (1979)
Havemann, R. H., Hamilton, C. A., and Harris, Richard E., “Photolithographic Fabrication of Lead Alloy Josephson Junctions,” J. Vac. Sci. Technology 15, 392 (1978)
Harris, R. E., Ginsberg, D. M., and Dynes, R. E., “Strong-coupling Correction to the Jump in the Quasiparticle Current of Superconducting Tunnel Junctions,” Phys. Rev. B 14, 993 (1976)
Harris, R. E., “Intrinsic Response Time of a Josephson Tunnel Junction,” Phys. Rev. B 13, 3818 (1976
Long-Term Stability of the NIST Standard Ultrasonic Source
No full textThe National Institute of Standards and Technology (NIST) Standard Ultrasonic Source (SUS) is a system comprising a transducer capable of output power levels up to 1 W at multiple frequencies between 1 MHz and 30 MHz, and an electrical impedance-matching network that allows the system to be driven by a conventional 50 Omega rf (radio-frequency) source. It is designed to allow interlaboratory replication of ultrasonic power levels with high accuracy using inexpensive readily available ancillary equipment. The SUS was offered for sale for 14 years (1985 to 1999). Each system was furnished with data for the set of calibration points (combinations of power level and frequency) specified by the customer. Of the systems that had been ordered with some calibration points in common, three were returned more than once to NIST for recalibration. Another system retained at NIST has been recalibrated periodically since 1984. The collective data for these systems comprise 9 calibration points and 102 measurements spanning a 17 year interval ending in 2001, the last year NIST ultrasonic power measurement services were available to the public. These data have been analyzed to compare variations in output power with frequency, power level, and time elapsed since the first calibration. The results verify the claim, made in the instruction sheet furnished with every SUS, that "long-term drift, if any, in the calibration of NIST Standard Sources is insignificant compared to the uncertainties associated with a single measurement of ultrasonic power by any method available at NIST.
Measurement of the fluorescence quantum yield using a spectrometer with an integrating sphere detector
No full textA method is proposed for measuring the fluorescence quantum yield (QY) using a commercial spectrophotometer with a 150 mm integrating sphere ( IS) detector. The IS detector is equipped with an internal cuvette holder so that absorbance measurements can be performed with the cuvette inside the IS. In addition, the spectrophotometer has a cuvette holder outside the IS for performing conventional absorbance measurements. It is shown that the fluorescence quantum yield can be obtained from a combination of absorbance measurements of the buffer and the analyte solution inside and outside the IS detector. Due to the simultaneous detection of incident and fluorescent photons, the absorbance measurements inside the IS need to be adjusted for the wavelength dependence of the photomultiplier detector and the wavelength dependence of the IS magnification factor. An estimate of the fluorescence emission spectrum is needed for proper application of the wavelength-dependent adjustments. Results are presented for fluorescein, quinine sulfate, myoglobin, rhodamine B and erythrosin B. The QY of fluorescein in 0.1 mol/L NaOH was determined as 0.90 +/- 0.02 where the uncertainty is equal to the standard deviation of three independent measurements. The method provides a convenient and rapid estimate of the fluorescence quantum yield. Refinements of the measurement model and the characteristics of the IS detector can in principle yield an accurate value of the absolute fluorescence quantum yield
Stiffening of the Extrapulmonary Arteries From Rats in Chronic Hypoxic Pulmonary Hypertension
No full textChanges in the compliance properties of large blood vessels are critical determinants of ventricular afterload and ultimately dysfunction. Little is known of the mechanical properties of large vessels exhibiting pulmonary hypertension, particularly the trunk and right main artery. We initiated a study to investigate the influence of chronic hypoxic pulmonary hypertension on the mechanical properties of the extrapulmonary arteries of rats. One group of animals was housed at the equivalent of 5000 m elevation for three weeks and the other held at ambient conditions of similar to 1600 m. The two groups were matched in age and gender. The animals exposed to hypobaric hypoxia exhibited signs of pulmonary hypertension, as evidenced by an increase in the RV/(LV+S) heart weight ratio. The extrapulmonary arteries of the hypoxic animals were also thicker than those of the control population. Histological examination revealed increased thickness of the media and additional deposits of collagen in the adventitia. The mechanical properties of the trunk, and the right and left main pulmonary arteries were assessed; at a representative pressure (7 kPa), the two populations exhibited different quantities of stretch for each section. At higher pressures we noted less deformation among the arteries from hypoxic animals as compared with controls. A four-parameter constitutive model was employed to fit and analyze the data. We conclude that chronic hypoxic pulmonary hypertension is associated with a stiffening of all the extrapulmonary arteries
Sources of Differences in On-Orbital Total Solar Irradiance Measurements and Description of a Proposed Laboratory Intercomparison
No full textThere is a 5 W/m(2) (about 0.35 %) difference between current on-orbit Total Solar Irradiance (TSI) measurements. On 18-20 July 2005, a workshop was held at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland that focused on understanding possible reasons for this difference, through an examination of the instrument designs, calibration approaches, and appropriate measurement equations. The instruments studied in that workshop included the Active Cavity Radiometer Irradiance Monitor III (ACRIM III) on the Active Cavity Radiometer Irradiance Monitor SATellite (ACRIMSAT), the Total Irradiance Monitor (TIM) on the Solar Radiation and Climate Experiment (SORCE), the Variability of solar IRradiance and Gravity Oscillations (VIRGO) on the Solar and Heliospheric Observatory (SOHO), and the Earth Radiation Budget Experiment (ERBE) on the Earth Radiation Budget Satellite (ERBS). Presentations for each instrument included descriptions of its design, its measurement equation and uncertainty budget, and the methods used to assess on-orbit degradation. The workshop also included a session on satellite- and ground-based instrument comparisons and a session on laboratory-based comparisons and the application of new laboratory comparison techniques. The workshop has led to investigations of the effects of diffraction and of aperture area measurements on the differences between instruments. In addition, a laboratory-based instrument comparison is proposed that uses optical power measurements (with lasers that underfill the apertures of the TSI instruments), irradiance measurements (with lasers that overfill the apertures of the TSI instrument), and a cryogenic electrical substitution radiometer as a standard for comparing the instruments. A summary of the workshop and an overview of the proposed research efforts are presented here
Non-contact methods for measuring front cavity depths of laboratory standard microphones using a depth-measuring microscope
No full textTo achieve an acceptable degree of accuracy at high frequencies in some standardized methods for primary calibration of laboratory standard (LS) microphones, the front cavity depth l(fc) of each microphone must be known. This dimension must be measured using non-contact methods to prevent damage to the microphone diaphragm. The basic capabilities of an optical depth-measuring microscope were demonstrated by the agreement of its measurements within 0.7 micro-m of the known values of reference gage blocks. Using this microscope, two basic methods were applied to measure l(fc) One (D) uses direct measurements at the microphone front surface annulus and conventional data reduction techniques. The other (GB) uses measurements at the surface of a gage block placed on the annulus, and plane-fitting data reduction techniques intended to reduce the effects of the slightly imperfect geometries of the microphones. The GB method was developed to provide a smoother surface of measurement than the relatively rough surface of the annulus, and to simulate the contact that occurs between the annulus and the smooth, plane surface of an acoustic coupler during microphone calibration. Using these methods, full data sets were obtained at 33 measurement positions (D), or 25 positions (GB). In addition, D and GB subsampling methods were applied by using subsamples of either the D or the GB full data sets. All these methods were applied to six LS microphones, three each of two different types. The GB subsampling methods are preferred for several reasons. The measurement results for l(fc) obtained by these methods agree well with those obtained by the GB method using the full data set. The expanded uncertainties of results from the GB subsampling methods are not very different from the expanded uncertainty of results from the GB method using the full data set, and are smaller than the expanded uncertainties of results from the D subsampling methods. Measurements of l(fc) using the GB subsampling method with only nine measurement positions exhibit expanded uncertainties (with coverage factor k = 2) within 4 micro-m and can improve the uncertainty of microphone calibrations by an order of magnitude over the result from use of generic standardized microphone type nominal l(fc) values and tolerance limits
A liquid density standard over wide ranges of temperature and pressure based on toluene
No full textThe density of liquid toluene has been measured over the temperature range -60 degrees C to 200 degrees C with pressures up to 35 MPa. A two-sinker hydrostatic-balance densimeter utilizing a magnetic suspension coupling provided an absolute determination of the density with low uncertainties. These data are the basis of NIST Standard Reference Material (R) 211d for liquid density over the temperature range -50 degrees C to 150 degrees C and pressure range 0.1 MPa to 30 MPa. A thorough uncertainty analysis is presented; this includes effects resulting from the experimental density determination, possible degradation of the sample due to time and exposure to high temperatures, dissolved air, uncertainties in the empirical density model, and the sample-to-sample variations in the SRM vials. Also considered is the effect of uncertainty in the temperature and pressure measurements. This SRM is intended for the calibration of industrial densimeters