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Displaying 176 - 200 of 3839

Reference measurements of Hydrogen's Dielectric Permittivity

August 10, 2009
Author(s)
James W. Schmidt, Michael R. Moldover, Eric F. May
… The measurements determine accurate values of hydrogen's molecular electric polarizability and its … calculated value 1.0×10 -5 K -1 . Our data also determine hydrogen's second dielectric virial coefficient, b ε,H2 = … dielectric constant, dielectric permittivity, helium, hydrogen …

Chapter 13. Color Quality of White LEDs

May 24, 2013
Author(s)
Yoshihiro Ohno
This chapter overviews the fundamentals of chromaticity and color rendering as the two important aspects of color quality of light sources for general illumination, with special focus on the use for solid state light sources. The section for chromaticity

Multifilmamentary Nb 3 Sn wires reacted in hydrogen gas

May 1, 2002
Author(s)
M Takayasu, R G. Ballinger, Ronald B. Goldfarb, A. A. Squitieri, P. J. Lee, David C. Larbalestier
… may be avoided by reacting in a reducing atmosphere of 5% hydrogen-95% argon. The effects of the hydrogen reaction on the superconductive properties of … the bronze wire and by 8% for the internal-tin wire by the hydrogen heat treatment, approximately proportional to the …

Ambient-Temperature Hydrogen Storage via Vanadium(II)-Dihydrogen Complexation in a Metal-Organic Framework

April 28, 2021
Author(s)
David Jaramillo, Henry Jiang, Hayden Evans, Romit Chakraborty, Hiroyasu Furukawa, Craig Brown, Martin Head-Gordon, Jeffrey Long
… of materials that strongly and reversibly adsorb hydrogen at ambient temperatures and moderate pressures could … optimal range of −15 to −25 kJ/mol for ambient-temperature hydrogen storage. Here, we report the hydrogen adsorption properties of the metal–organic framework …

Role of microstructure and composition in resisting hydrogen embrittlement of fastener grade steels

July 13, 2009
Author(s)
Nicholas Nanninga, Jack Grochowski, Lloyd Heldt, Karl Rundman
… The degree of hydrogen embrittlement for several fastener grade steels has … determined. The technique used to assess the resistance to hydrogen embrittlement of the steels was the rising step load … alteration resulted in some improvement in resistance to hydrogen embrittlement, the overriding factor contributing to …

High-brightness Cs focused ion beam from a cold-atomic-beam ion source

May 2, 2017
Author(s)
Adam V. Steele, Andrew Schwarzkopf, Jabez J. McClelland, Brenton Knuffman
… of focal spot size and brightness in a focused ion beam system utilizing a laser-cooled atomic beam source … than the highest brightness observed in a Ga liquid metal ion source. The behavior of brightness as a function of beam … as next-generation circuit edit and nanoscale secondary ion mass spectrometry. …

Photoluminescence Quenching in Si 1-x Ge x /Si Multiple Quantum Wells Grown With Atomic Hydrogen

March 1, 1999
Author(s)
Greg Balchin, Paul M. Amirtharaj, C Silvestre, P E. Thompson
… x /Si (0.1 {1-xGe x /Si MQW samples grown without atomic hydrogen. No quantum confined photoluminescence was observed … in the Si 1-x Ge x /Si MQW samples grown with atomic hydrogen. This was unexpected since quantum confined photoluminescence has been observed in the hydrogen-assisted growth of Si 1-x Ge x /Si quantum-well …

Magneto-Optical-Trap-Based, High Brightness Ion Source for Use as a Nanoscale Probe

August 21, 2008
Author(s)
James L. Hanssen, Shannon B. Hill, Jon Orloff, Jabez J. McClelland
… on the demonstration of a low emittance, high brightness ion source based on magneto-optically trapped neutral atoms. Our source has ion optical properties comparable to or better than those of the commonly used liquid metal ion source. In addition, it has several advantages that offer …

In-situ Kinetics Studies on Hydrogenation of Transition Metal (=Ti, Fe) Doped Mg Films

March 1, 2010
Author(s)
Zhuopeng Tan, Edwin J. Heilweil, Leonid A. Bendersky
… Ti and Fe additives on Mg hydride growth rates. Compare to hydrogenation of pure Mg, Ti additives (atomic fraction 1.6 % … a thicker hydride layer residing on top of the films. Mg Hydrogenation rate is increased by an order of magnitude for … layer is thicker than twice of the hydride layer in hydrogenation of pure Mg case. Results obtained here can be …

Ion Solvation in Water Acetonitrile Mixtures

January 1, 2001
Author(s)
Raymond D. Mountain
… The results of a preliminary molecular dynamics study of ion (NA+ and Cl-) solvation and association in water, … is expected to be an important factor governing ion solvation and association. Results for ions in pure water … than the temperature in determining the degree of ion association. Preliminary results for the mixtures are …

Assessing girth weld quality of pipeline steels and their susceptibility to hydrogen embrittlement

June 16, 2024
Author(s)
Zack Buck, Newell Moser, May Ling Martin, Nicholas Derimow, Damian Lauria, Enrico Lucon, Douglas Stalheim, Peter Bradley, Matthew Connolly
… Hydrogen is known to cause premature failure in various steel … understanding the susceptibility of these steels to hydrogen embrittlement and the effect of various … results of mechanical measurements performed in air and in hydrogen of girth welds used in pipeline steels. Fracture …

Alkali metal pyridinolate/piperidinolate pairs: A new type of materials for efficient reversible hydrogen storage

April 1, 2025
Author(s)
Alexis Munyentwali, Yang Yu, Xingchi Zhou, Wei Zhou, Qijun Pei, Khai Chen Tan, Anan Wu, Hui Wu, Teng He, Ping Chen
… Chemical hydrogen storage in organic materials is a promising method … This study proposes a strategy to design a new type of hydrogen storage materials, i.e., alkali metal … suitable dehydrogenation thermodynamics along with high hydrogen storage capacities. These air-stable compounds can …

Micro-fabricated stylus ion trap

August 7, 2013
Author(s)
Kyle S. McKay, Christian L. Arrington, Ehren D. Baca, Jonathan J. Coleman, Yves Colombe, Patrick Finnegan, Dustin A. Hite, Andrew E. Hollowell, Robert Jordens, John D. Jost, Dietrich G. Leibfried, Adam M. Rowen, Ulrich J. Warring, David J. Wineland, David P. Pappas, Andrew C. Wilson
… stylus Paul trap was designed to confine a single atomic ion for use as a sensor to probe the electric-field noise of … with the UV-LIGA technique to reduce the distance of the ion from the surface of interest. We detail the fabrication … environment. After cooling a motional mode of the ion at 4 MHz close to its ground state (n = 0.34 � 0.07), the …

Advances in source technology for focused ion beam instruments

April 1, 2014
Author(s)
Noel Smith, John Notte, Adam V. Steele
… Owing to the development of new ion source technology, users of focused ion beams (FIBs) have an increasingly wide array of uniquely … capable platforms to choose from. Specifically, the new ion sources are able to offer superior performance in several … ion sources, focused ion beams, inductively coupled plasma, …

Development of the NIST Detector-based Color Temperature Scale

May 17, 2006
Author(s)
George P. Eppeldauer, Yoshihiro Ohno
Based on the spectral responsivity of the channels of a tristimulus colorimeter, a color temperature scale is being developed at NIST. The low uncertainty of the spectral responsivity measurements can dominate the chromaticity measurement uncertainty. New

Motional Squeezing for Trapped Ion Transport and Separation

August 20, 2021
Author(s)
Robert Sutherland, Shaun Burd, Daniel Slichter, Stephen Libby, Dietrich Leibfried
… Transport, separation, and merging of trapped ion crystals are essential operations for most large-scale … framework, we develop a new, general protocol for trapped ion transport, separation, and merging. We show that motional squeezing can prepare an ion wave packet to enable transfer from the ground state of …

Negative Cesium Sputter Ion Source for Generating Cluster Primary Ion Beams for Secondary Ion Mass Spectrometry Analysis

April 1, 2001
Author(s)
John G. Gillen, R L. King, B Freibaum, R Lareau, J Bennett, F Chmara
… The use of a cluster (or polyatomic) primary ion projectile for organic SIMS has been demonstrated to … use of a commercially available negative cesium sputter ion as a means of generating cluster ion beams on our Cameca IMS 4F and 6F magnetic sector SIMS … cluster beam, depth profiling, organic secondary ion mass spectrometry …

Developing Ideal Metalorganic Hydrides for Hydrogen Storage: From Theoretical Prediction to Rational Fabrication

September 6, 2021
Author(s)
Zijun Jing, Qinqin Yuan, Yang Yu, Xiangtao Kong, Khai C. Tan, Jintao Wang, Qijun Pei, Xue-Bin Wang, Wei Zhou, Hui Wu, Anan Wu, Teng He, Ping Chen
… Materials for hydrogen storage have been extensively explored for a few decades. Thousands of hydrogen storage materials have been synthesized and tested, … hydrides, 20 of them were identified with both high hydrogen capacities (≥5 mass %) and suitable thermodynamics …

Competition Between Intra-and Inter-Molecular Hydrogen Bonding: Effect on Para/Ortho Adsorptive Selectivity for Substituted Phenols

February 1, 2000
Author(s)
A J. Glemza, K L. Mardis, A A. Chaudhry, M K. Gilson, G F. Payne
… small molecule ethyl propionate (EP) as an analogue of the hydrogen bond accepting site of the acrylic ester sorbent. … p-MHB and p-HAP bind to EP primarily via an intermolecular hydrogen bond to the carbonyl oxygen of EP. In contrast, o-MHB and o-HAP possess strong intramolecular hydrogen bonds that are retained upon complexation with EP. …

Helium Ion Microscopy: A New Technique for Semiconductor Metrology and Nanotechnology

January 1, 2007
Author(s)
Michael T. Postek, Andras Vladar, John A. Kramar, L A. Stern, John Notte, Sean McVey
… The Helium Ion Microscope (HIM) offers a new, potentially disruptive … the helium ions, it is theoretically possible to focus the ion beam into a smaller probe size relative to that of an … achievable. In contrast to the SEM, when the helium ion beam interacts with the sample, it generates …

Medium-Term Frequency Stability of Hydrogen Masers as Measured by a Cesium Fountain

June 2, 2010
Author(s)
Thomas E. Parker, Steven R. Jefferts, Thomas P. Heavner
… Abstract Hydrogen masers are used extensively in time scale ensembles, … frequency stability (tau = 30 to 90 days) of six hydrogen masers. An unexpected observation was a moderate … atomic frequency standards, cesium fountain, hydrogen maser … Medium-Term Frequency Stability of Hydrogen Masers as Measured by a Cesium Fountain …

Bright focused ion beam sources based on laser-cooled atoms

March 24, 2016
Author(s)
Jabez J. McClelland, Adam V. Steele, Brenton J. Knuffman, Kevin A. Twedt, Andrew D. Schwarzkopf, Truman M. Wilson
… Nanoscale focused ion beams (FIBs) represent one of the most useful tools in … ionization of laser cooled neutral atoms to produce the ion beam. The extremely cold temperatures attainable with … the brightness of the industry standard Ga+ liquid metal ion source. In this review we discuss the context of ion beam …

Trapped Highly Charged Ion Plasmas

January 1, 2002
Author(s)
E Takacs, John D. Gillaspy
… Electron beam Ion Trap (EBIT) devices are reviewed with special attention to applications in highly charged ion plasma research. EBIT properties are presented based on … parameter, Brillouin radius, magnetic trapping mode, ion cloud shape, density, temperature, rotation, and …
Displaying 176 - 200 of 3839
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