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NIST Authors in Bold

Displaying 1001 - 1025 of 2934

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

Coil motion effects in watt balances: a theoretical check

February 10, 2016
Author(s)
Stephan Schlamminger, Shisong Li, Darine El Haddad, Frank C. Seifert, Leon S. Chao, Jon R. Pratt
A watt balance is a precision apparatus for the measurement of the Planck constant that has been proposed as a primary method for realizing the unit of mass in a revised International System of Units. In contrast to an ampere balance, which was

A significant-loophole-free test of Bell's theorem with entangled photons

December 16, 2015
Author(s)
Marissa Giustina, Marijn Versteegh, Soren Wengerowsky, Johannes Handsteiner, Armin Hochrainer, Kevin Phelan, Fabian Steinlechner, Johannes Koffler, Larsson Jan-Ake, Carlos Abellan, Waldimar Amaya, Valerio Pruneri, Morgan Mitchell, Joern Beyer, Thomas Gerrits, Adriana Lita, Krister Shalm, Sae Woo Nam, Thomas Scheidl, Rupert Ursin, Bernhard Wittmann, Anton Zeilinger
Local realism is the worldview in which physical properties of objects exist independently of measurement and where physical influences cannot travel faster than the speed of light. Bell's theorem states that this worldview is incompatible with the

Construction of a watt balance with the aim to realize the kilogram at the National Institute of Standards and Technology

August 1, 2014
Author(s)
Darine El Haddad, Leon Chao, Frank Seifert, David B. Newell, Jon R. Pratt, Stephan Schlamminger
A redefinition of the International System of Units, the SI, is impending and could occur as early as 2017. After redefinition a means to realize the unit of mass is required. A watt balance is a promising device to realize the unit of mass at the kilogram

Experimental test of an event-based corpuscular model modification as an alternative to quantum mechanics

February 13, 2013
Author(s)
Giorgio Brida, Ivo P. Degiovanni, Marco Genovese, Alan L. Migdall, Fabrizio Piacentini, Sergey Polyakov, Paola Traina
We present the first experimental test that distinguishes between an Event-Based Corpuscular Model (EBCM)9) of the interaction of photons with matter and quantum mechanics. The test looks at the interference that results as a single photon passes through a

Optimizing Acoustic Measurements of the Boltzmann Constant

November 22, 2009
Author(s)
Michael R. Moldover
We review the progress in acoustic metrology of gases that has occurred since the 1988 measurement of the universal gas constant R using a spherical acoustic resonator. The advances in understanding resonators and in calculating the thermophysical

Electron Self-Energy for the K and L Shells at Low Nuclear Charge

April 1, 2001
Author(s)
U Jentschura, Peter J. Mohr, G Soff
A nonperturbative numerical evaluation of the one-photon electron self energy for the K- and L-shell states of hydrogen like ions with nuclear charge numbers Z = 1 to 5 is described. Our calculation for the 1S 1/2 state has a numerical uncertainty of 0.8

A Result from the NIST Watt Balance and an Analysis of Uncertainties

April 1, 1999
Author(s)
Richard L. Steiner, David B. Newell, Edwin R. Williams
An improved determination of the ratio of power, measured in terms of the Josephson and quantum Hall effects, and also the meter, kilogram, and second, has been completed. The result is expressed as: W 90/W = 1 + (8187) x 10 -9. This is an order of

An Accurate Measurement of Planck's Constant

July 1, 1998
Author(s)
Edwin R. Williams, Richard L. Steiner, David B. Newell
Using a moving coil watt balance, electric power measured in terms of the Josephson and quantum Hall effects is compared with mechanical power measured in terms of the meter, kilogram and second, we find the Planck constant h = 6.62606891(58) x 10 -34 Js

Development of an automated millifluidic platform and data-analysis pipeline for rapid electrochemical corrosion measurements: a pH study on Zn-Ni

July 25, 2022
Author(s)
Howie Joress, Brian DeCost, Najlaa Hassan, Trevor Braun, Justin Gorham, Jason Hattrick-Simpers
We describe the development of a millifluidic based scanning droplet cell platform for rapid and automated corrosion. This system allows for measurement of corrosion properties (e.g., open circuit potential, corrosion current through Tafel and linear

An Ontological Modeling Platform

June 4, 2008
Author(s)
V.C. Liang, Conrad E. Bock, XuanFang Zha
The Ontological Modeling Platform described in this paper is a class library for extended ontological operations, to support extension of ontology languages, composition of interconnected elements, and high-level product modeling services, such as

Mode-selective acoustic spectroscopy of trigonal piezoelectric crystals

May 1, 2008
Author(s)
Ward L. Johnson, Carlos F. Martino, Sudook A. Kim, Paul R. Heyliger
A noncontacting electromagnetic-acoustic-resonance technique is presented for generating and detecting vibrational modes with prescribed symmetries in piezoelectric trigonal crystals with cylindrical geometry. This technique provides the experimental basis

2-D Imaging of Temperature in CF 4 Plasmas

April 1, 2005
Author(s)
Kristen L. Steffens, Mark A. Sobolewski
Two-dimensional maps of rotational temperature were determined in CF4 plasmas using planar laser-induced fluorescence of CF. Experiments were performed in a capacitively-coupled, parallel plate plasma reactor at pressures from 200mTorr (26.7Pa) to 800mTorr

The Boundary of X-Ray and Electron Tomography

January 3, 2005
Author(s)
Zachary H. Levine
Samples a few micrometers in total size offer a challenge to both x-ray and electron tomography. X-ray tomography originated imaging the human body with millimeter resolution, but the resolution has been reduced by over 7 orders of magnitude by the use of

Electrometrology and NIST -- New Directions

July 1, 2001
Author(s)
William E. Anderson
I gaze into a somewhat cloudy crystal ball to predict the directions of electrical metrology in the next fifteen years. The emphasis on standards based on fundamental constants of nature and on quantum-mechanical principles will move from the base units to
Displaying 1001 - 1025 of 2934
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