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Displaying 16276 - 16300 of 74219

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

Model-based engineering for the integration of manufacturing systems with advanced analytics

July 10, 2016
Author(s)
David Lechevalier, Anantha Narayanan Narayanan, Sudarsan Rachuri, Sebti Foufou, Yung-Tsun Lee
To employ data analytics effectively and efficiently on manufacturing systems, engineers and data scientists need to collaborate closely to bring their domain knowledge together. In this paper, we introduce a domain-specific modeling approach to integrate

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

Third Generation of Adapted Wheatstone Bridge for High Resistance Measurements at NIST

July 10, 2016
Author(s)
Dean G. Jarrett, Shamith Payagala, Marlin E. Kraft, Kwang Min Yu
A third generation of adapted Wheatstone bridge is being developed at NIST to improve high resistance measurements and scaling from 1 TΩ to 10 PΩ. Improvements to extend range and reduce uncertainties include automated calibration of the voltage sources

10 Volt Automated Direct Comparison of Two Cryocooled Programmable Josephson Voltage Standards

July 9, 2016
Author(s)
Alain Rufenacht, Yi-hua D. Tang, Paul Dresselhaus, Charles J. Burroughs, Robert E. Schwall, Samuel P. Benz
We have performed direct dc comparisons between two cryocooled 10 V programmable Josephson voltage standards utilizing an automated synchronization scheme for the voltage reversals, which enables the use of a high sensitivity null detector on its 3 µV

Direct comparison of a Pulse-driven Josephson Arbitrary Waveform Synthesizer and a Programmable Josephson Voltage Standard at 1 Volt

July 9, 2016
Author(s)
Alain Rufenacht, Nathan Flowers-Jacobs, Anna Fox, Charles J. Burroughs, Paul Dresselhaus, Samuel P. Benz
We have performed direct ac comparisons between two types of quantum voltage standards, a pulse- driven Josephson arbitrary waveform synthesizer and a programmable Josephson voltage standard, at 1 V rms amplitude and a frequency of 100 Hz. The system

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

Josephson-Based Full Digital Bridge for High-Accuracy Impedance Comparisons

July 9, 2016
Author(s)
Frederic Overney, Nathan Flowers-Jacobs, Blaise Jeanneret, Alain Rufenacht, Anna Fox, Jason Underwood, Andrew D. Koffman, Samuel P. Benz
This paper describes a Josephson-based impedance bridge capable of comparing any types of impedance over a large bandwidth. The heart of the bridge is a dual AC Josephson Voltage Standards (ACJVS) source which offers unprecedented flexibility in high

Laser Refractometer as a Transfer Standard of the Pascal

July 9, 2016
Author(s)
Patrick Egan, Jack A. Stone Jr., Jacob Edmond Ricker, Jay H. Hendricks
We have developed a new low pressure sensor which is based on the measurement of (nitrogen) gas refractivity inside a Fabry-Perot (FP) cavity. We compare pressure determinations via this laser refractometer to that of well-established ultrasonic manometers

Simultaneous Double Waveform Synthesis with a Single Programmable Josephson Voltage Standard

July 9, 2016
Author(s)
Alain Rufenacht, Anna Fox, Paul Dresselhaus, Charles J. Burroughs, Samuel P. Benz, Bryan C. Waltrip, Thomas L. Nelson
We have recently demonstrated new 2 V PJVS devices configured with two voltage outputs and two sets of least significant bits in order to simultaneously generate two independent stepwise output waveforms. This development improves upon our previous

Influence of Antimony-Halogen Additives on Flame Propagation

July 8, 2016
Author(s)
Valeri I. Babushok, Peter Deglmann, Gregory T. Linteris, Roland H. Kraemer
A kinetic model for flame inhibition by antimony-halogen compounds in hydrocarbon flames is developed. Thermodynamic data for the relevant species are assembled from the literature, and calculations are performed for a large set of additional species of Sb

PORPHYRIN-BASED CHEMISTRY FOR CARBON CAPTURE AND SEQUESTRATION

July 8, 2016
Author(s)
Winnie K. Wong-Ng, Lawrence P. Cook, Greg Brewer
Two major types of porphyrinic framework structures offer promise for carbon capture and sequestration (CCS) applications: 1) metal-organic frameworks (MOFs) in which the porphyrins serve as struts linking vertices comprised of metal -based clusters; 2)

Traceable Dynamic Calibration of Force Transducers by Primary Means

July 8, 2016
Author(s)
Nicholas Vlajic, Akobuije Chijioke
We describe an apparatus for traceable, dynamic calibration of force transducers using harmonic excitation, and report calibration measurements of force transducers using this apparatus. In the apparatus, the force applied to the transducer is produced by

Adsorption of Two Gas Molecules at a Single Metal Site in a Metal-Organic Framework

July 7, 2016
Author(s)
Tomce Runcevski, Matthew T. Kapelewski, Rodolfo M. Torres-Gavosto, Jacob Daniel Tarver, Craig Brown, Jeffrey R. Long
One strategy to markedly increase the gas storage capacity of metal-organic frameworks, is to introduce coordinatively-unsaturated metal centers capable of binding multiple gas molecules. Herein, we provide an initial demonstration that a single mental

Advancing X-Ray Scattering Metrology Using Inverse Genetic Algorithms

July 7, 2016
Author(s)
Adam F. Hannon, Daniel F. Sunday, Donald A. Windover, Regis J. Kline
We compare the speed and effectiveness of two genetic optimization algorithms to the results of statistical sampling via a Markov Chain Monte Carlo algorithm to find which is the most robust method for determining real space structure in periodic gratings

Design of 280 GHz feedhorn-coupled TES arrays for the balloon-borne polarimeter SPIDER

July 7, 2016
Author(s)
Johannes Hubmayr, Jason E. Austermann, James A. Beall, Daniel T. Becker, Shannon M. Duff, Arpi L. Grigorian, Gene C. Hilton, Joel N. Ullom, Michael R. Vissers
We describe 280 GHz bolometric detector arrays that instrument the balloon-borne polarimeter spider. A primary science goal of spider is to measure large-scale B-mode polarization of the cosmic microwave back-ground (cmb) in search of the cosmic-inflation

Dynamic Signature of Molecular Association in Methanol

July 7, 2016
Author(s)
Christopher E. Bertrand, Jeffrey L. Self, John R. Copley, Antonio Faraone
Quasielastic neutron scattering measurements and molecular dynamics simulations were combined to investigate the collective dynamics of deuterated methanol. A slow, non-Fickian mode was observed in addition to the standard heat mode. The qualitative

Influence of Hydrocarbon Moiety of DMMP on Flame Propagation in Lean Mixtures

July 7, 2016
Author(s)
Gregory T. Linteris, Valeri I. Babushok, Viswanath R. Katta, Fumiaki Takahashi
Phosphorus-containing compounds (PCCs) have been found to be significantly more effective than CF3Br for reducing burning velocity when added to stoichiometric hydrocarbon-air flames. However, when added to lean flames, DMMP (dimethylmethylphosphonate) is

Interconversion of Peptide Mass Spectral Libraries Derivatized with iTRAQ or TMT Labels

July 7, 2016
Author(s)
Zheng Zhang, Xiaoyu Yang, Yuri A. Mirokhin, Dmitrii V. Tchekhovskoi, Weihua Ji, Sanford P. Markey, Pedatsur Neta, Bowen A. Michael, Stephen E. Stein
Derivatizing peptides with isobaric tags such as iTRAQ and TMT is widely employed in proteomics due to their ability to multiplex quantitative measurements. We recently made publicly available a large peptide library derived from iTRAQ 4-plex labeled

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
Displaying 16276 - 16300 of 74219
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