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An Algorithm for Identifying Optimal Spreaders in a Random Walk Model of Network Communication
No full textIn a model of network communication based on a random walk in an undirected graph, what subset of nodes (subject to constraints on the set size), enables the fastest spread of information? The dynamics of spread is described by a process dual to the movement from informed to uninformed nodes. In this setting, an optimal set A minimizes the sum of the expected first hitting times F(A), of random walks that start at nodes outside the set. Identifying such a set is a problem in combinatorial optimization that is probably NP hard. F has been shown to be a supermodular and non-increasing set function and fortunately some results on optimization of such functions exist, e.g., in the work of Ilev.
In this paper, the problem is reformulated so that the search for solutions to the problem is restricted to a class of optimal and “near” optimal subsets of the graph. We introduce a submodular, non-decreasing rank function ρ, that permits some comparison between the solution obtained by the classical greedy algorithm and one obtained by our methods. The supermodularity and non-increasing properties of F are used to show that the rank of our solution is at least 1(1)e− times the rank of the optimal set. When the solution has a higher rank than the greedy solution this. constant can be improved to (1 + χ)1(1)e− where χ > 0 is determined a
posteriori. The method requires the evaluation of F for sets of some fixed cardinality m, where m is much smaller than the cardinality of the optimal set. Given =νρA(), a class of examples is presented that illustrate the tradeoff between m and solution quality ν
Diesel Adsorption to Polyvinyl Chloride and Iron During Contaminated Water Flow and Flushing Tests
No full textThis paper presents an experimental and theoretical study of aqueous diesel contamination and decontamination of a polyvinyl chloride (PVC) surface and an iron (Fe) surface. A test apparatus designed for the purpose of studying adsorption of diesel from a flowing dilute diesel/water mixture was used to measure the mass of diesel adsorbed per unit surface area (the excess surface density) and the bulk concentration of the diesel in the flow using a fluorescence based measurement technique. Both bulk composition and the excess surface density measurements were achieved via a traverse of the fluorescent measurement probe perpendicular to the test surface. The diesel adsorption to each test surface was examined for three different Reynolds numbers between zero and 7000. Measurements for a given condition were made over a period of approximately 200 h for a diesel mass fraction of approximately 0.15 % in tap water. For a Reynolds number of approximately 7000, the largest excess layer thickness was approximately 4.4 μm, which was measured on a PVC surface. Averaging over all contaminating flow rates and exposure times, the excess layer thickness on the PVC surface was approximately 2.0 μm. Reynolds number had little or no effect on the accumulation of diesel on an iron surface, which was approximately 0.71 μm. The adsorbed diesel on the PVC and iron surfaces was removed by flushing with tap water. Models to predict excess layer thickness during flushing and contamination were developed. The models predict flushing times to within 7 h and predict the influence of pipe surface on contamination level
An Evaluation of Gas Phase Enthalpies of Formation for Hydrogen-Oxygen (HxOy) Species
No full textWe have compiled gas phase enthalpies of formation for nine hydrogen-oxygen species (HxOy) and selected recommended values for H, O, OH, H2O, HO2, H2O2, O3, HO3, and H2O3. The compilation consists of values derived from experimental measurements, quantum chemical calculations, and prior evaluations. This work updates the recommended values in the NIST-JANAF (1985) and Gurvich et al. (1989) thermochemical tables for seven species. For two species, HO3 and H2O3 (important in atmospheric chemistry) and not found in prior thermochemical evaluations, we also provide supplementary data consisting of molecular geometries, vibrational frequencies, and torsional potentials which can be used to compute thermochemical functions. For all species, we also provide supplementary data consisting of zero point energies, vibrational frequencies, and ion reaction energetics
OptSortSph: Optical Sorting in a Standing Wave Field Calculated with Effective Velocities and Diffusion Constants
No full textRecently, as part of a study of the ability of a Gaussian standing-wave interference field to sort small dielectric spheres entrained in a moving fluid, we implemented a two-length-scale method to determine the trajectories of the particles. In the first step, effective velocities and diffusion constants are determined by solving the Fokker-Planck equation in a force field determined by the Maxwell stress tensor. In the second step, these effective constants of motion are used to predict positions of particles swept across the interference field. Here, we present the code which was used in a companion article [1].
The fine scale tracks a domain of typically 16 interference fringes with a spatial resolution typically 1/16 of a fringe. The Fokker-Planck equation tracks the evolution of the probability distribution of a sphere in a period set of one-dimensional sinusoidal wells. Physically, these sinusoidal wells exist because of the interaction between the dielectric particle and the electromagnetic standing wave. The effective velocity is determined by finding the mean position of the sphere as a function of time. After allotting time for intra-well equilibration, the mean position becomes a linear function of time. The slope of this line is the velocity. Similarly, the diffusion constant is related to the time evolution of the second moment of the distribution. The effective velocity and diffusion constant needs to be found for a sphere of a given radius for a range of optical intensities.
The coarse scale is given by the size of the width of the standing wave, typically 3 mm. Although the position is a continuous variable, the solution is unaware of the fringes except to the extent that there is a position-dependent effective velocity and effective diffusion constant which is determined on the fine scale above. The crossing time is a simple function of the transverse distance between the starting position and end line. A simple approximation to the distribution of crossing times (induced by diffusion) is made, however, uniform motion across the interference field is assumed. The distance travelled longitudinally is found by integrating the effective velocity across the Gaussian envelope of the interference field. diffusion constant is integrated as well to find the standard deviation of the position at the exit. A correction is made for the standard deviation of the crossing time.
By default, the notebook is configured to reproduce some of the more interesting results of Ref. [1], specifically the particle radii for which the position on exit is a very sensitive function of the radius. The user is encouraged to explore other configurations.
[1] Curry JJ and Levine ZH (2016) Continuous feed optical sorting of aerosol particles. Optics Express 24:14100-14123. http://dx.doi.org/10.1364/OE.24.01410
Raymond L. Driscoll
No full textRAYMOND L. DRISCOLL
NBS/NIST: 1936-1971
INDUCTED: 2016
Birth: 11 October 1905, Toano, Virginia
Death: 28 July 1998
EDUCATION:
College of William and Mary, BA (Physics), 1928
University of North Carolina, MA (Physics), 1936
CITATION:
For significantly advancing metrology through absolute determinations of the ampere and the proton gyromagnetic ratio in water, contributing crucially to the implementation of the SI, the determination of fundamental constants, and bringing atomic magnetic resonance techniques into electrical metrology at NBS.
POSITIONS HELD AT NBS/NIST:
Physicist, Organic and Fibrous Materials Division, 1936-1937
Physicist, Electricity Division, Institute for Basic Standards, 193 7-1971
Volunteer consultant, Electricity Division, Center for Absolute Physical Quantities, National Measurement Laboratory, 1971-1995
HONORS:
American Men of Science (1953)
U.S. Department of Commerce Silver Medal (1950) and Gold Metal (1959), then termed" Meritorious Service"
and "Exceptional Service" Awards
NBS Samuel Wesley Stratton Award (1962)
MEMBERSHIP:
American Physical Society
PUBLICATIONS:
More than 15 publications and a patent including:
Curtis, R.W., Driscoll, R.L., and Critchfield, C.L., "An Absolute Determination of the Ampere, Using Helical
and Spiral Coils," Journal of Research of the NBS, 28, Issue 2, 133-157 (Feb 1940)
Driscoll, R.L., "Determination of Current in Absolute Measure," Phys. Rev. 99, Issue 2, 634 (1955)
Driscoll, R.L., "Measurement of Current With a Pellat-Type Electrodynamometer," Journal of Research of the
NBS, 60, Issue 4, 287-296 (1958)
Driscoll, R.L. and Cutkosky, R.D., "Measurement of Current with the NBS Current Balance," Journal of
Research of the NBS, 60, Issue 4, 297-305 (1958)
Driscoll, R.L. and Bender, P.L., "Proto Gyromagnetic Ratio," Phys. Rev. Lett., 1, Issue 11, 413-414 (1958) Driscoll, R.L. and Olsen, P.T., "Application of Nuclear Resonance to the Monitoring of Electrical Standards," Precision Measurement and Fundamental Constants; NBS Special Publication 343, 117-121 (1971
Robert N. Goldberg
No full textROBERT N. GOLDBERG
NBS/NIST: 1969-2008
INDUCTED: 2016
B: 11 December 1943, Stamford, Connecticut
EDUCATION:
The Johns Hopkins University, BS (Chemistry), 1965 Carnegie-Mellon University, PhD (Physical Chemistry), 1969 Postdoctoral fellowship, Mellon Institute and the University of Pittsburgh, 1968-1969
CITATION:
For pioneering research in microcalorimetry in conjunction with extensive studies on the thermodynamics of enzyme-catalyzed reactions of great significance to both biotechnology and fundamental biochemistry, and for assembling the world's largest bio-thermodynamic database, i.e. the Thermodynamics of Enzyme-catalyzed Reactions Database.
POSITIONS HELD AT NBS/NIST:
Research Scientist, Biochemical Science Division, Chemical Science and Technology Laboratory (CSTL), 1969-2002 Group Leader, Bioprocess Measurements, Biochemical Science Division, CSTL, 2002-2004
Acting Chief, Biochemical Science Division, CSTL, 2005-2006
Team Leader, Biospectroscopy Group, Biochemical Science Division, CSTL, 2006
Group Leader, Biospectroscopy, Biochemical Science Division, CSTL, 2007-2008
Scientist Emeritus, Biosystems and Biomaterials Division, Material Measurement Laboratory, 2008-present
HONORS:
Fellow, American Institute of Chemists
Phi Lambda Upsilon
Sigma Xi
NIST Measurement Services Award (1995)
Honorary Fellow, Center for Advanced Research and Biotechnology
MEMBERSHIPS:
ASTM International
BioPax
Calorimetry Conference
IUPAC Commissions: Chemical Thermodynamics and Commission on Biophysical Chemistry (Vice-Chair) Editorial Advisory Board, Handbook of Chemistry and Physics
Guest Editor, Journal of Physical Chemistry Band Journal of Chemical Thermodynamics
PUBLICATIONS:
More than 150 publications including:
Goldberg, R.N., "Thermodynamics of Hexokinase Catalyzed Reactions," Biophys. Chem. 3, 192-205 (1975) Tewari, Y.B. and Goldberg, R.N., "Thermodynamics of the Conversion of Aqueous Glucose to Fructose," J. Solution
Chem. 13, 523-547 (1984)
Goldberg, R.N. and Tewari, Y.B., "Thermodynamic and Transport Properties of Carbohydrates and their
Monophosphates: the Pentoses and Hexoses," J. Phys. Chem. Ref Data 18, 809-880 (1989)
Rekharsky, M.V., Goldberg, R.N., Schwarz, F.P., Tewari, Y.B., Ross, P.D., Yamashoji, Y., and Inoue, Y.,
"Thermodynamic and Nuclear Magnetic Resonance Study of the Interactions of α- and β-Cyclodextrin with Model
Substances: Phenethylamine, Ephedrines, and Related Substances," J. Am. Chem. Soc. 117, 8830-8840 (1995) Akers D.L. and Goldberg, R.N., "BioEqCalc: A Package for Performing Equilibrium Calculations on Biochemical
Reactions," Mathematica Journal 8, 86-113 (2001)
Goldberg, R.N., Schliesser, J., Mittal, A., Decker, S.R., Santos, A.F.L.O.M., Freitas, V.L.S., Urbas, A., Lang, B.E., Heiss, C., Ribeiro da Silva, M.D.M.C., Woodfield, B.F., Katahira, R., Wang, W., and Johnson, D.K.,
"A Thermodynamic Investigation of the Cellulose Allomorphs: Cellulose(Am), Cellulose lβ(Cr), Cellulose ll(Cr), and Cellulose IIl(Cr)", J. Chem. Thermodyn. 81, 184-226 (2015
Human Plasma Metabolites Measured with Different Liquid Chromatography/Mass Spectrometry (LC/MS) Platforms
No full textNon-targeted global metabolite profiles of Standard Reference Material (SRM) 1950 Metabolites in HumanPlasma were obtained on five different liquid chromatography/mass spectrometry (LC/MS) instrument combinations using identically prepared samples. Different instruments rendered significantly different metabolite profiles, however, the results were highly reproducible when working with one instrument. A full description of the measurements and data analysis have been previously published [1]. Presented here are the raw data on which Ref. [1] is based. For a further description of SRM 1950 and the general analysis of its chemical composition, see Refs. [2] and [3]. [1] Telu KH, Yan X, Wallace WE, Stein SE, Simón-Manso Y (2016) Analysis of human plasma metabolites across different liquid chromatography/mass spectrometry platforms: Cross-platform transferable chemical signatures. Rapid Commun Mass Spectrom 30(5):581-593. http://dx.doi.org/10.1002/rcm.7475
[2] Phinney KW, et al. (2013) Development of a Standard Reference Material for metabolomics research. Anal Chem 85(24):11732-11738. http://dx.doi.org/10.1021/ac402689t
[3] Simón-Manso Y, et al. (2013) Metabolite profiling of a NIST Standard Reference Material for human plasma (SRM 1950): GC-MS, LC-MS, NMR, and clinical laboratory analyses, libraries, and web-based resources. Anal Chem 85(24):11725-11731. http://dx.doi.org/10.1021/ac402503
Experimental Assessment of the Equivalent Strain Rate for an Instrumented Charpy Test
No full textInstrumented Charpy test data can be used to obtain estimates of dynamic yield strength, by means of a well-established relationship published by W. Server in 1978. A fundamental issue in comparing measured dynamic tensile properties and Charpy-based estimations is establishing the equivalent uniaxial strain rate for an instrumented Charpy test, typically conducted at ≈ 5.5 m/s. In this investigation, by performing tensile tests at various strain rates and instrumented Charpy tests for 10 different materials, we compared values of dynamic yield strength both measured from tensile tests and estimated by means of Server’s equation. The obtained equivalent Charpy strain rates were found to vary significantly from material to material, and to correlate reasonably with specific values of absorbed energy measured during the impact tests
Managing Risks Due to Ingredient Variability in Food Production
No full textManaging the design of products and the efficient execution of the manufacturing processes needed to produce them is an endeavor fraught with all manner of risks for manufacturing enterprises large and small. In certain industries, such as the food manufacturing industry, the problems and risks can be even greater. This is because the processes necessary for a food product’s manufacture must be designed not only to meet quality, cost, and efficiency targets, but also to have an innate flexibility to cope with the unavoidable variability in the characteristics of the ingredients used to produce the desired product. In the food manufacturing industry and in related industries such as pharmaceutical manufacturing, the problem of identifying vendor sources for ingredients that have acceptable characteristics, managing the acquisition of those ingredients, and then modifying the manufacturing process to cope with the inherent variability in ingredients acquired at different times is an ongoing concern that can expose a company to severe risks. In this paper, a case study will be presented that illustrates how smart manufacturing (SM) approaches can be applied to reduce the risks due to ingredient variability to, and increase the efficiency of, a food production network. Smart manufacturing integrates best-of-breed solutions from manufacturing and non-manufacturing arenas to solve manufacturing problems and offers great hope for manufacturers. The SM solution described in this paper is built upon what is called the Smart Manufacturing Platform, a software and services platform being developed by the Smart Manufacturing Leadership Coalition
Digital Manufacturing Certificate Toolkit: Adding Trust and Traceability to Product Data
No full textThe NIST Digital Manufacturing Certificate (DMC) Toolkit is a toolkit designed specifically to provide certification—digital signature using software and hardware certificates and verification—of manufacturing related data. The DMC toolkit supports signature and validation of data in the following formats: ISO 10303-21 (STEP) [1], ISO 6983 (G-code) [2], ISO 32000 (PDF) [3] and 14739 (PRC, a.k.a. 3D PDF) [4], and Quality Information Framework (QIF) [5]. The project offers the Toolkit as a .NET API (written in C#), a command-line tool, and a fully-functional demonstration application. 1] International Organization for Standardization (2002) ISO 10303-21:2002 — Industrial automation systems and integration --Product data representation and exchange --Part 21: Implementation methods: Clear text encoding of the exchange structure (International Organization for Standardization, Geneva, Switzerland).
[2] International Organization for Standardization (2009) ISO 6983-1:2009 — Automation systems and integration --Numerical control of machines --Program format and definitions of address words --Part 1: Data format for positioning, line motion and contouring control systems (International Organization for Standardization, Geneva, Switzerland).
[3] International Organization for Standardization (2008) ISO 32000-1:2008 — Document management --Portable document format --Part 1: PDF 1.7 (International Organization for Standardization, Geneva, Switzerland).
[4] International Organization for Standardization (2014) ISO 14739-1:2014 — Document management --3D use of Product Representation Compact (PRC) format --Part 1: PRC 10001 (International Organization for Standardization, Geneva, Switzerland).
[5] Dimensional Metrology Standards Consortium (2015) Quality Insurance Framework (QIF). Available http://qifstandards.org/. Accessed November 28, 2016.
[6] Hedberg JTD, Krim