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Displaying 551 - 575 of 2606

NIST Micronutrients Measurement Quality Assurance Program Winter 2015 Comparability Studies: Results for Round Robin LXXVII Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 42 Ascorbic Acid in Human Serum

July 28, 2016
Author(s)
Jeanice M. Brown Thomas, David L. Duewer
The National Institute of Standards and Technology coordinates the Micronutrients Measurement Quality Assurance Program (MMQAP) for laboratories that measure fat- and water-soluble vitamins and carotenoids in human serum and plasma. This report describes

Design of a Table-Top Watt Balance

July 26, 2016
Author(s)
Stephan Schlamminger, Jon R. Pratt, David B. Newell, Frank C. Seifert, Michael Liu, Leon S. Chao, Luis Manuel Pea Prez, Shisong Li, Darine El Haddad
Measurements of the Planck constant with watt balances using 1 kg masses have achieved relative standard uncertainties below 2 x 10-8. Having established a metrological link between the kilogram and this fundamental constant of nature, a redefinition of

Targets for Relative Range Error Measurement of 3D Imaging Systems.

July 25, 2016
Author(s)
Prem K. Rachakonda, Balasubramanian Muralikrishnan, Katharine M. Shilling, Geraldine S. Cheok, Vincent D. Lee, Christopher J. Blackburn, Dennis S. Everett, Daniel S. Sawyer
The Dimensional Metrology Group (DMG) at the National Institute of Standards and Technology (NIST) is performing research to support the development of documentary standards within ASTM E57 for the point-to-point performance evaluation of 3D imaging

Test method for measuring the electrical output of electroshock weapons

July 25, 2016
Author(s)
Nicholas G. Paulter Jr., David M. Jenkins, Norimitsu Ichikawa, Michael Leonesio
Electroshock weapons (ESWs) have become a ubiquitous component of weapons used in the arsenal of domestic law enforcement (LE) agencies and the military around the world. It is a major contributor to the escalation of force policies and procedures of many

Versatile fluidic cell for in-situ electrochemical measurements in SEM

July 24, 2016
Author(s)
Jeyavel Velmurugan, Ana Stevanovic, Feng Yi, David A. LaVan, Andrei Kolmakov
Electrochemical techniques such as like electrodeposition are crucially important for fabrication of nanostructured materials. The details of cluster nucleation and growth at early stages of electrodeposition are extremely important for morphology and

Phonon Anharmonicity in Bulk Td-MoTe2

July 18, 2016
Author(s)
Albert Davydov, Sergiy Krylyuk, Irina Kalish, Ryan Beams, Patrick Vora
We examine anharmonic contributions to the optical phonon frequency in bulk Td-MoTe2 phase through temperature-dependent Raman spectroscopy. At temperatures greater than 100 K we find that the optical phonon modes redshift linearly with temperature in

First mass measurements with the NIST-4 watt balance

July 10, 2016
Author(s)
Darine El Haddad, Leon S. Chao, Frank C. Seifert, David B. Newell, Jon R. Pratt, Stephan Schlamminger
In the past four years, we have constructed a new watt balance at the National Institute of Standards and Technology (NIST), with the goal to realize the unit of mass after the redefinition of the International System of Units, expected to occur in 2018

Improvement of Leakage Resistance of PJVS for NIST-4 Watt Balance Experiment

July 10, 2016
Author(s)
Yi-hua D. Tang, Frank C. Seifert, Stephan Schlamminger
A Programmable Josephson Voltage Standard (PJVS) system is used for the voltage measurements in NIST-4 Watt balance experiment. It is critical to enhance the leakage resistance of the PJVS in order to achieve the uncertainty of voltage measurements better

Quantum Hall Resistance Traceability for the NIST-4 Watt Balance

July 10, 2016
Author(s)
Dean G. Jarrett, Randolph Elmquist, Marlin E. Kraft, George R. Jones Jr., Shamith Payagala, Frank Seifert, Stephan Schlamminger, Darine El Haddad
Scaling from the quantum Hall resistance to 100 Ω standard resistors used by the NIST-4 Watt Balance involves multiple resistance standards and bridges to provide the lowest possible uncertainty. Described here is the infrastructure and procedures

Improved spectra aberration in the Johnson Noise Thermometry

July 9, 2016
Author(s)
Alessio Pollarolo, Horst Rogalla, Anna Fox, Kevin J. Coakley, Weston L. Tew, Samuel P. Benz
SPECTRAL ABERRATION HAS BEEN FOR A LONG TIME THE MAIN SOURCE OF UNCERTAINTY IN THE JOHNSON NOISE THERMOMETRY APPROACH TO MEASURING THE BOLTZMANN CONSTANT. RECENTLY, WITH NEWLY DEVELOPED HARDWARE AND THE INTRODUCTION OF A NOVEL FITTING ALGORITHM FOR

Local coexistence of VO2 phases revealed by deep data analysis

July 7, 2016
Author(s)
Evgheni Strelcov, Anton Ievlev, Alex Belianinov, Alexander Tselev, Andrei A. Kolmakov, Sergei Kalinin
We report a synergistic approach of micro-Raman spectroscopic mapping and deep data analysis to study the distribution of crystallographic phases and ferroelastic domains in a defected Al-doped VO2 microcrystal. Bayesian linear unmixing revealed an uneven

Certification Report for the Reference Materials ERM-AE142 and ERM-EB400 A pure Pb solution and a bronze material, both certified for their Pb isotope amount ratios

July 1, 2016
Author(s)
Jochen Vogl, Dorit Becker, Maren Koenig, Yong-Hyeon Yim, Kyoung-Seok Lee, Heidi Goenaga-Infante, Dmitriy Malinowskiy, Sarah Hill, Tongxiang Ren, Jun Wang, Robert D. Vocke Jr., Karen E. Murphy, Naoko Nonose, Olaf Rienitz, Janine Noordmann
Lead isotope analysis is often applied in various fields such as archaeology, geochemistry and forensic science. Despite this, only the 3 primary isotopic reference materials NIST SRM; 981, NIST SRM 982 and NIST SRM 983 are available, whereby NIST SRM 981
Displaying 551 - 575 of 2606