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Displaying 1376 - 1400 of 2957

What Metrology Gains With Quantized Resistance Standards

December 1, 2000
Author(s)
Randolph E. Elmquist
The emergence of quantum metrology is expressed in modern electrical standards, primarily through the Josephson effect and the quantum Hall effect. The Josephson and von Klitzing constants that relate to these standards are given in quantum theory by ideal

Microform Calibration Uncertainties of Rockwell Diamond Indenters

September 1, 1995
Author(s)
Jun-Feng Song, F Rudder, Theodore V. Vorburger, J Smith
National and international comparisons in Rockwell hardness tests show significant differences. Uncertainties in the geometry of the Rockwell diamond indenters are largely responsible for these differences. By using a stylus instrument, with a series of

CHARACTERIZATION OF MICROWAVE BLACKBODY WITH MONOSTATIC MEASUREMENT

September 5, 2024
Author(s)
Dazhen Gu, Jonah Smith, Adam Whitney, Omar Khatib, Natalie Rozman, Amanda Gregg, Willie Padilla, William Deal, Steven Reising
This paper describes a characterization method for measuring the reflectivity of blackbodies used as calibration devices in spaceborne instruments. The fundamental measurement principle is based on the scattering matrix theory. A monostatic apparatus has

Telecommunication Testbed Repeatability Assessment

September 16, 2022
Author(s)
Jeanne Quimby, Jake Rezac, Mary Gregg, Michael Frey, Jason Coder, Anna Otterstetter
Telecommunication testbeds are a fundamental tool in communication research, enabling prototyping and validating new ideas. Unfortunately, these testbeds are often highly complex, costly, and challenging to operate, requiring simultaneous Open System

Supercontinuum generation in an on-chip silica waveguide

February 13, 2014
Author(s)
Scott A. Diddams, Dong Yoon Oh, David Sell, Hansuek Lee, Ki Youl Yang, Kerry J. Vahala
Supercontinuum generation is demonstrated in an on-chip silica spiral waveguide by launching 180-fs pulses from an optical parametric oscillator at the center wavelength 1330 nm. With a coupled pulse energy of 2.17 nJ, the broadest spectrum in the

Time Measurement

February 3, 2014
Author(s)
Michael A. Lombardi
… the evolution of clocks and timekeeping, time scales, the fundamentals of time measurement, and the various time …

Defining Units in the Quantum SI

February 18, 2008
Author(s)
Peter J. Mohr
Possible changes to the International System of Units (SI) are being discussed, including a proposal to define the units by specifying the values of a set of fundamental constants. This note is meant to be an elementary guide to the algebra associated with

Scanning Tunneling Microscope - Web Page

November 1, 2006
Author(s)
Marilyn E. Jacox, John William Gadzuk
The scanning tunneling microscope [STM] is widely used in both industrial and fundamental research to obtain atomic-scale images of metal surfaces. It provides a three-dimensional profile of the surface which is very useful for characterizing surface

Quantum information processing with trapped ions

July 25, 2004
Author(s)
Murray D. Barrett, Tobias Schaetz, J Chiaverini, Dietrich Leibfried, Joseph W. Britton, Wayne M. Itano, John D. Jost, Emanuel Knill, C. Langer, R Ozeri, David J. Wineland
We report experiments on the creation and manipulation ofmulti-particle entangled states of trapped atomic ions. The experiments reported here, quantum dense coding and quantum teleportation, constitute a significant step toward performing large-scale

Virtual Testing of Ready-Mixed Concrete

January 1, 2004
Author(s)
Jeffrey W. Bullard
The development of a virtual testing system is no small task. It requires fundamental scientific research into the physics, chemistry, and materials science of concrete. The Virtual Cement and Concrete Testing Laboratory consortium has identified three

Trapped-Ion Quantum Simulator,

January 1, 1998
Author(s)
David J. Wineland, C Monroe, Wayne M. Itano, B E. King, Dietrich G. Leibfried, C J. Myatt, Chris S. Wood
Coherent manipulations involving the quantized motional and internal states of a single trapped ion can be used to simulate the dynamics of other systems. We consider some examples, including the action of a Mach Zehnder interferometer which uses entangled

Elastic Flexure of Bilayered Beams Subject to Strain Differentials

December 1, 2000
Author(s)
Tze J. Chuang, S K. Lee
The residual stresses present in a thin film and the curvatures formed at its substyrate during deposition have been a great concern to electrochemists and process engineers. Here a new hybrid analytical method is presented to reanalyze the flexural

Carbon Nanotube-Based Black Coatings

February 15, 2018
Author(s)
John H. Lehman, Christopher S. Yung, Nathan A. Tomlin, Davis R. Conklin, Michelle S. Stephens
… We briefly describe a history of other coatings such as nickel phosphorous, gold black and carbon-based paints and …

On neutron holography, neutron interferometry, and neutron orbital angular momentum

September 26, 2025
Author(s)
Wolfgang Treimer, Frank Hausser, Ingeborg Beckers, Suda Martin, Terrence Jach
A neutron Laue crystal interferometer has been reported by Saranac et al . to demonstrate neutron holography of a spiral phase plate. Using its two coherent beams as the object and reference beams, the resulting interference pattern was interpreted as a

Operando analysis of the positive active mass of lead batteries by neutron diffraction

January 30, 2024
Author(s)
Miguel Rodriuqez-Goemz, Javier Campo, Aloida Orera, Fernando de La Fuente, Jesus Valenciano, Holger Fricke, Yan Chen, Ke An, Daniel Hussey, Angel Larrea
We have analysed, through neutron diffraction experiments with the volume-gauge technique, the in operando performance of lead cells composed of industrial positive and negative electrodes, previously tank formed in the manufacturing plant. The cells, 6.5
Displaying 1376 - 1400 of 2957
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