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Path-Integral Calculation of the Second Dielectric and Refractivity Virial Coefficients of Helium, Neon, and Argon
No full textWe present a method to calculate dielectric and refractivity virial coefficients using the path-integral Monte Carlo formulation of quantum statistical mechanics and validate it by comparing our results with equivalent calculations in the literature and with more traditional quantum calculations based on wavefunctions. We use state-of-the-art pair potentials and polarizabilities to calculate the second dielectric and refractivity virial coefficients of helium (both He-3 and He-4), neon (both Ne-20 and Ne-22), and argon. Our calculations extend to temperatures as low as 1 K for helium, 4 K for neon, and 50 K for argon. We estimate the contributions to the uncertainty of the calculated dielectric virial coefficients for helium and argon, finding that the uncertainty of the pair polarizability is by far the greatest contribution. Agreement with the limited experimental data available is generally good, but our results have smaller uncertainties, especially for helium. Our approach can be generalized in a straightforward manner to higher-order coefficients
MARY H. SAUNDERS
No full textNBS/NIST: 1993–2008 and 2011–2017
INDUCTED into the NIST Gallery of Distinguished Scientists, Engineers, and Administrators: 2020
Birth: 1955, Falls Church, Virginia
EDUCATION:
Vanderbilt University, BA (Political Science), 1977
Princeton University, MPA (Public Policy), 1979
CITATION: For exceptional leadership in standards policy development and implementation at the highest levels of government and the private-sector-led standards community and as NIST’s Chief Operating Officer
POSITIONS HELD AT NBS/NIST:
Group Leader, Global Standards Program, Office of Standards Services, Technology Services, 1994-2001
Program Analyst, Program Office, Office of the NIST Director, 1999-2001
Chief, Standards Services Division, Technology Services, 2001-2008
Director, Standards Coordination Office, Office of the NIST Director, 2011-2012
NIST Associate Director for Management Resources, 2012-2017
(From 2008-2011 Mary Saunders served at the Department of Commerce as Deputy Assistant Secretary, Manufacturing and Services, International Trade Administration.)
SIGNIFICANCE OF WORK:
During Ms. Saunders’ more than two decades in the NIST standards program she made significant contributions leveraging her expertise in public policy, markets, trade, and government policy and regulation, along with serving as leader of NIST’s standards coordination efforts. She was influential in developing NIST’s capability to work effectively with private sector stakeholders and voluntary standards organizations to develop consensus standards that enhanced government and business performance and stimulated trade. She managed the Standards in Trade Workshop program, working with the private sector to train hundreds of senior foreign government officials on the U.S. standards and regulatory systems, facilitating trade in 10 key industry sectors through foreign adoption of U.S.-based standards. She established and maintained comprehensive databases of more than 500 U.S. standards-developing and conformity-assessment organizations, over 30 U.S. government standards-related programs, and more than 10,000 voluntary standards incorporated by reference in U.S. regulations. She developed the Administration's comprehensive policy memorandum addressing U.S. government agency engagement in private sector-led standards activities to address national priorities. Ms. Saunders led NIST's participation in the Department of Commerce shared services initiative, increasing the efficiency of mission support services in human resources, information technology, finance, and acquisitions. Ms. Saunders was instrumental in ensuring her staff could effectively engage across a large number of federal agencies; work with OMB and the White House on policy and interagency activities; and support trade activities both by U.S. companies, and by the government through its trade agreements and trade policy work.
HONORS:
NIST Bronze Medal (1995, 2001, and 2007)
U.S. Department of Commerce Silver Medal (1999, 2000, and 2005)
ANSI Meritorious Service Award (2004)
George S. Wham Leadership Medal (2011)
MEMBERSHIPS:
American National Standards Institute
ASTM International
IEE
Linking Theory to Practice: Predicting Ballistic Performance from Mechanical Properties of Aged Body Armor
No full textIt has long been a goal of the body armor testing community to establish an individualized, scientific-based protocol for predicting the ballistic performance end of life for fielded body armor. A major obstacle in achieving this goal is the test methods used to ascertain ballistic performance, which are destructive in nature and require large sample sizes. In this work, using both the Cunniff and Phoenix-Porwal models, we derived two separate but similar theoretical relationships between the observed degradation in mechanical properties of aged body armor and its decreased ballistic performance. We present two studies used to validate the derived functions. The first correlates the degradation in mechanical properties of fielded body armor to the degradation produced by a laboratory accelerated-aging protocol. The second examines the ballistic resistance and the extracted-yarn mechanical properties of new and laboratory-aged body armor made from poly(p-phenylene-2,6-benzobisoxazole), or PBO, and poly(p-phenylene terephthalamide), or PPTA. We present correlations found between the tensile strengths of yarns extracted from armor and the ballistic limit (V-50) when significant degradation of the mechanical properties of the extracted yarns was observed. These studies provided the basis for a validation data set in which we compared the experimentally measured V-50 ballistic limit results to the theoretically predicted V-50 results. The theoretical estimates were generally shown to provide a conservative prediction of the ballistic performance of the armor. This approach is promising for the development of a tool for fielded armor performance surveillance relying upon mechanical testing of armor coupon samples
Optical Quantum Memory and its Applications in Quantum Communication Systems
No full textOptical quantum memory is a device that can store the quantum state of photons and retrieve it on demand and with high fidelity. It is emerging as an essential device to enhance security, speed, scalability, and performance of many quantum systems used in communications, computing, metrology, and more. In this paper, we will specifically consider the impact of optical quantum memory on quantum communications systems. Following a general overview of the theoretical and experimental research progress in optical quantum memory, we will outline its role in quantum communications, including as a photon source, photon interference, quantum key distribution (QKD), quantum teleportation, quantum repeater, and quantum networks
So, You Want to Have a Nanofab? Shared-Use Nanofabrication and Characterization Facilities: Cost-of-Ownership, Toolset, Utilization, and Lessons Learned
No full textNanofabrication/characterization facilities enable research and development activities across a host of science and engineering disciplines. The collection of tools and supporting infrastructure necessary to construct, image, and measure micro- and nanoscale materials, devices, and systems is complex and expensive to establish, and it is costly to maintain and optimize. As a result, these facilities are typically operated in a shared-use mode. We discuss the key factors that must be considered to successfully create and sustain such facilities. These include the need for long-term vision and institutional commitment, and the hands-on involvement of managers in facility operations. We consider startup, operating, and recapitalization costs, together with algorithms for cost recovery and tool-time allocation. The acquisition of detailed and comprehensive project and tool-utilization data is essential for understanding and optimizing facility operations. Only such a data-driven decision-making approach can maximize facility impact on institutional goals. We illustrate these concepts using the National Institute of Standards and Technology (NIST) NanoFab as our test case, but the methodologies and resources presented here should be useful to all those faced with this challenging task
Digitizing "The NBS Tables of Chemical Thermodynamic Properties: Selected Values for Inorganic and C1 and C2 Organic Substances in SI Units"
No full textThe NBS Tables of Chemical Thermodynamic Properties [1] is a collection of thermodynamic properties, published in book form, consisting of 103 tables with 14 330 critically evaluated species. The tables were originally published as a series of NBS2 Technical Notes [2]. As a result of this work, the data is now available in a more accessible spreadsheet format Enthalpy of formation, Delta H-f degrees, Gibbs energy of formation, Delta(f)G degrees, entropy, S degrees, heat capacity at constant pressure, C-p degrees, all at 298.15 K, and the enthalpy difference, [H degrees(298) - H degrees(0)] are provided where known. Within this collection of data, there are no values given for transuranic elements, Np to Lr (Tables 77-87)
Thrombin: An Approach to Developing a Higher-Order Reference Material and Reference Measurement Procedure for Substance Identity, Amount, and Biological Activities
No full textThrombin, the proteolytic enzyme that catalyzes the transformation of soluble fibrinogen to the polymerized fibrin clot, participates in multiple reactions in blood coagulation in addition to the clotting reaction. Although reference materials have existed for many years, structural characterization and measurement of biological activity have never been sufficient to permit claims of clear metrological traceability for the thrombin preparations. Our current state-of-the-art methods for protein characterization and determination of the catalytic properties of thrombin now make it practical to develop and characterize a metrologically acceptable reference material and reference measurement procedure for thrombin. Specifically, alpha-thrombin, the biologically produced protease formed during prothrombin activation, is readily available and has been extensively characterized. Dependences of thrombin proteolytic and peptide hydrolytic activities on a variety of substrates, pH, specific ions, and temperature are established, although variability remains for the kinetic parameters that describe thrombin enzymatic action. The roles of specific areas on the surface of the thrombin molecule (exosites) in substrate recognition and catalytic efficiency are described and characterized. It is opportune to develop reference materials of high metrological order and technical feasibility. In this article, we review the properties of alpha-thrombin important for its preparation and suggest an approach suitable for producing a reference material and a reference measurement procedure that is sensitive to thrombin's catalytic competency on a variety of substrates
Design Considerations to Improve Charpy Instrumented Strikers
No full textInstrumented impact testing allows the applicability of conventional Charpy tests to be extended toward assessing mechanical properties such as dynamic fracture toughness and dynamic tensile properties. In this work, we present design considerations for engineering instrumented strikers for Charpy V-notch impact testing. Specific attention is given to the mechanical and geometric features, as well as the placement of strain gauges and corresponding bridge circuits for instrumentation. These design considerations are intended to make the sensitivity invariant to the location and distribution of impact forces. The concepts presented in this work were applied to an actual instrumented striker, which was then statically calibrated. Data from this calibration indicate that the device has good repeatability, shows a linear response, and is relatively insensitive to impact location
DANIEL W. LOZIER
No full textDANIEL W. LOZIER
TENURE AT NBS/NIST: 1969–2019
INDUCTED into the NIST Gallery of Distinguished Scientists, Engineers, and Administrators: 2020
Birth: 1941, Portland, Oregon
EDUCATION:
Oregon State University, BA (Mathematics), 1962
American University, MA (Mathematics), 1969
University of Maryland, PhD (Applied Mathematics), 1979
CITATION: For outstanding technical contributions and exceptional leadership to provide an online, interactive, and authoritative reference for special functions of applied mathematics, the NIST Digital Library of Mathematical Functions
POSITIONS HELD AT NBS/NIST:
Mathematician, Information Technology Laboratory (ITL) and predecessors, 1969-2003
Leader, Mathematical Software Group, Applied and Computational Mathematics Division, ITL, 2003-2012
Re-employed Annuitant, Applied and Computational Mathematics Division, ITL, 2012-2019
HONORS:
Adjunct Professor (Applied Mathematics), University of Maryland (1986-1997)
Associate Editor, Mathematics of Computation, American Mathematical Society (1996-2008)
President, NIST Chapter of Sigma Xi (1998-1999)
Associate Editor, Journal of Numerical Analysis, Industrial and Applied Mathematics, European Society of Computational Methods in Sciences and Engineering (2008-2018)
U.S. Department of Commerce Gold Medal (2011)
Outstanding IT Achievement in Government, Government Computer News (2011)
Award for Excellence in Mathematics and Computer Science, Washington Academy of Sciences (2017)
Fellow, Washington Academy of Sciences (2017)
MEMBERSHIPS:
American Mathematical Society
Society for Industrial and Applied Mathematics
Sigma Xi
Cosmos Club
Philosophical Society of Washington
Washington Academy of Sciences
PUBLICATIONS:
More than 40 publications including:
Smith, J.M., Olver, F.W.J., and Lozier, D.W., “Extended-Range Arithmetic and Normalized Legendre Polynomials”, ACM Transactions on Mathematical Software, Vol. 7, No. 1, pp. 93-105 (1981)
Lozier, D.W. and Olver, F.W.J., “Airy and Bessel Functions by Parallel Integration of ODEs”, Proceedings of the Sixth SIAM Conference on Parallel Processing for Scientific Computing, (R.F. Sincovec, D.E. Keyes, M.R. Leuze, L.R. Petzold, and D.A. Reed, eds.), Society for Industrial and Applied Mathematics, pp. 530-538 (1993)
Lozier, D.W. and Olver, F.W.J., “Numerical Evaluation of Special Functions”, Mathematics of Computation 1943-1993: A Half-Century of Computational Mathematics, (W. Gautschi, ed.), American Mathematical Society, pp. 79-125, (Invited survey) (1994)
Lozier, D.W., Miller, B.R, and Saunders, B.V., “Design of a Digital Mathematical Library for Science, Technology and Education”, Proceedings of the IEEE Forum on Research and Technology Advances in Digital Libraries, IEEE Computer Society Press, pp.118-128 (1999)
Lozier, D.W., “NIST Digital Library of Mathematical Functions”, Annals of Mathematics and Artificial Intelligence Vol. 38, pp.105-119 (2003)
Olver, F.W.J., Lozier, D.W., Boisvert, R.F., and Clark, C.W. (eds.), NIST Handbook of Mathematical Functions, Cambridge University Press, 968 pages (2010