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Displaying 16351 - 16375 of 73892

DELAY MEASUREMENT OF 1PPS SIGNALS IN TIMING SYSTEMS

May 9, 2016
Author(s)
Stefania Romisch, Daniele Rovera, Marco Siccardi
Abstract The uncertainty of time measurements in timing systems is not only a function of the quality of the instruments and system components (time interval counters, pulse distribution amplifiers, GNSS receivers) but lays also in the quality of the

Dynamic Onset of Feynman Relation in the Phonon Regime

May 9, 2016
Author(s)
Lu Deng, Edward W. Hagley, Yan Li, Chengjie Zhu
The Feynman relation 1, a much celebrated condensed matter physics gemstone for more than 70 years, predicts that the density excitation spectrum and structure factor of a condensed Bosonic system in the phonon regime drops linear and continuously to zero

End-to-End Quality Information Framework (QIF) Technology Survey

May 9, 2016
Author(s)
John L. Michaloski, Thomas D. Hedberg, Hui-Min Huang, Thomas R. Kramer
The goal of this paper is to understand how quality information characterizing the manufactured parts can be reported in a XML standardized format. The Quality Information Framework (QIF) is an ANSI standard sponsored by the Dimensional Metrology Standards

High Thermopower with Metallic Conductivity in p-Type Li-Substituted PbPdO 2

May 9, 2016
Author(s)
Leo K. Lamontagne, Geneva Laurita, Michael W. Gaultois, Michael Knight, Leila Ghadbeigi, Taylor D. Sparks, Markus E. Gruner, Rossitza Pentcheva, Craig Brown, Ram Seshadri
PbPdO 2 is a band semiconductor with a band gap arising from the filled d 8 nature of square-planar Pd 2+. We establish that hole doping through Li substitution for Pd in PbPdO 2 results in a p-type metallic oxide with a positive temperature coefficient of

High Thermopower with Metallic Conductivity in p/p}-Type Li-Substituted PbPdO 2

May 9, 2016
Author(s)
Leo K. Lamontagne, Geneva Laurita, Michael W. Gaultois, Michael Knight, Leila Ghadbeigi, Taylor D. Sparks, Markus E. Gruner, Craig Brown, Ram Seshadri
Early age hydration kinetics of Portland cement with pozzolanic volcanic ash was examined using quasi-elastic neutron scattering. Volcanic ash consisting of two different particle sizes was used to prepare cement pastes by combinations of Portland cement

Measurement of AM-to-PM Conversion in a Quartz-MEMS Resonator

May 9, 2016
Author(s)
Craig W. Nelson, Archita Hati, David A. Howe
This work investigates the new aspects of the non-linear response in a quartz-MEMS resonator at 635 MHz. We characterize its major cause of AM-to-PM conversion as a function of power and drive frequency; this is important in developing noise compensation

Optical design and initial Results from NISTs AMMT/TEMPS Facility

May 9, 2016
Author(s)
Steven E. Grantham, Brandon M. Lane, Jorge E. Neira, Sergey Mekhontsev, Leonard M. Hanssen, Mihaela Vlasea
NIST’s Physical Measurement and Engineering Laboratories are jointly developing the Additive Manufacturing Measurement Testbed (AMMT)/ Temperature and Emittance of Melts, Powders and Solids (TEMPS) facilities. These facilities will be co-located on an open

Power Splitter Thermal Noise Correlations in Cross-spectrum Noise Measurements

May 9, 2016
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
We discuss collapse of the cross-spectrum phase noise measurement of thermally-limited oscillator due to anti-correlated thermal noise of the Wilkinson power splitter. We also examine effect of thermal noise of various resistive power splitters on such

Practical Evaluation of a 50 km Fiber Link Utilizing a Commercial Modem

May 9, 2016
Author(s)
Corey A. Barnes, Archita Hati, Craig W. Nelson, David A. Howe
We evaluate the stability of two-way time and frequency transfer over a 50 km fiber optic link established using a commercially available fiber optic modem. For this evaluation we report the residual phase noise, total Allan deviation, total time deviation

Thermophysical Properties of Carbon Dioxide and CO2-Rich Mixtures

May 9, 2016
Author(s)
Allan H. Harvey, Ian H. Bell, Marcia L. Huber, Arno R. Laesecke, Eric W. Lemmon, Christopher W. Meyer, Chris D. Muzny, Richard A. Perkins
This report summarizes the results of work performed under DOE/NETL Interagency Agreement DE- FE0003931, which began in October 2011 and ended (after a 6-month no-cost extension) March 31, 2015. The key objectives for this work were to: (1) Measure the dew

Frequency shift mitigation in a cold-atom CPT clock

May 8, 2016
Author(s)
Xiaochi Liu, John Kitching, Elizabeth Donley, Eugene N. Ivanov
An upgrade in the laser interrogation system for our cold-atom clock based on coherent population trapping has resulted in a reduced light shift. The new approach makes use of an electro-optic modulator to significantly reduce the phase coherence of the

A Simulation Framework for Industrial Wireless Networks and Process Control Systems

May 6, 2016
Author(s)
Yongkang Liu, Richard Candell, Nader Moayeri, Kang B. Lee
Factory and process automation systems are increasingly employing information and communications technologies to facilitate data sharing and analysis in integrated control operations. Wireless connections provide flexible access to a variety of field

Detecting leaks in gas-filled pressure vessels using acoustic resonances

May 6, 2016
Author(s)
Keith A. Gillis, Michael R. Moldover, James B. Mehl
We demonstrate that a leak from a large, unthermostatted pressure vessel into ambient air can be detected an order of magnitude more effectively by measuring the time dependence of the ratio p/f 2 than by measuring the ratio p/T. Here f is the resonance

Realizing Exactly Solvable SU(N) Magnets with Thermal Atoms

May 6, 2016
Author(s)
Michael Beverland, Gorjan Alagic, Michael Martin, Andrew Koller, Ana Maria Rey, Alexey Gorshkov
We show that n thermal fermionic alkaline-earth atoms in a flat-bottom trap allow one to robustly implement a spin model displaying two symmetries: the Sn symmetry that swaps atoms occupying different vibrational levels of the trap and the SU(N) symmetry

Angularly-Selective Transmission Imaging in a Scanning Electron Microscope

May 5, 2016
Author(s)
Jason D. Holm, Robert R. Keller
This contribution presents recent advances in imaging control conditions for transmission scanning electron microscopy (t-SEM) by means of angularly-selective electron collection with a commercial scanning transmission electron microscopy-in-scanning

Understanding and Control of Bipolar Doping in Copper Nitride

May 5, 2016
Author(s)
Angela N. Fioretti, Craig P. Schwartz, John Vinson, Dennis Nordlund, David Prendergast, Adele C. Tamboli, Filip Tuomisto, Stephan Lany, Eric S. Toberer, Andriy Zakutayev
Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu3N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit

Coherent cavity-enhanced dual-comb spectroscopy

May 4, 2016
Author(s)
Adam J. Fleisher, David A. Long, Zachary D. Reed, David F. Plusquellic, Joseph T. Hodges
Multiheterodyne spectroscopy performed with two stabilized optical frequency combs (OFCs) has shown great potential as a fast, accurate, and high-resolution substitute for existing interferometry methods that require lengthy integration times and precision

UTSA-74: A MOF-74 Isomer with Two Accessible Binding Sites per Metal Center for Highly Selective Gas Separation

May 4, 2016
Author(s)
Feng Luo, Changsheng Yan, Lilong Dang, Rajamani Krishna, Wei Zhou, Hui Wu, Xinglong Dong, Yu Han, Tong-Liang Hu, Michael O'Keeffe, Lingling Wang, Mingbiao Luo, Rui-Biao Lin, Banglin Chen
A new metal-organic framework Zn 2(H 2O)(dobdc)¿0.5(H 2O) (UTSA-74, H 4dobdc=2,5-dioxido-1,4- benzenedicarboxylic acid), Zn-MOF-74/CPO-27-Zn isomer, has been synthesized and structurally characterized. It has a novel four coordinated fgl topology with one
Displaying 16351 - 16375 of 73892
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