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Displaying 18276 - 18300 of 73929

How Large Can We Go? Isolation of > 1 nm Diameter Single-Wall Carbon Nanotubes Species using Aqueous Two Phase Extraction

April 14, 2015
Author(s)
Jeffrey A. Fagan, Erik Haroz, Rachelle Ihly, Hui Gui, Jeffrey Blackburn, Jeffrey R. Simpson, Stephen K. Doorn, Stephanie Lam, Angela R. Hight Walker, Ming Zheng
We demonstrate the effective separation of near-monochiral single-wall carbon nanotube (SWCNT) species with diameters > 1 nm through multi-stage aqueous two phase extraction (ATPE), and report an empirical function for the surfactant concentrations at

Nanoscale Spin Valve Josephson Junction Devices

April 14, 2015
Author(s)
Burm Baek, William H. Rippard, Matthew R. Pufall, Samuel P. Benz, Stephen E. Russek, Horst Rogalla, Paul D. Dresselhaus
Traditionally, superconductivity and magnetism have had a mutually exclusive relationship. However, the physics of superconductor-ferromagnet hybrid structures turned out to be far from being simply destructive, which has led to the hope of a new breed of

Pass / Fail / Inconclusive Criteria for Inter-Laboratory Comparisons

April 14, 2015
Author(s)
Blaza Toman, Bodo Mickan, Gerd Wubbeler, Olha Bodnar, Clemens Elster, John D. Wright
Inter-laboratory comparisons use the best available transfer standards to check participants uncertainty analyses, identify underestimated uncertainty claims or measurement errors, and improve the global measurement system. For some measurands (e.g. flow)

Privacy Amplification in the Isolated Qubits Model

April 14, 2015
Author(s)
Yi-Kai Liu
Isolated qubits are a special class of quantum devices, which can be used to implement tamper-resistant cryptographic hardware such as one-time memories (OTM's). Unfortunately, these OTM constructions leak some information, and standard methods for privacy

Scatterfield Microscopy and the Fundamental Limits of Optical Defect Metrology

April 14, 2015
Author(s)
Richard M. Silver, Bryan M. Barnes, Martin Y. Sohn, Hui Zhou
Defect inspection remains a critical manufacturing challenge due to the competing requirements between throughput and very high resolution. Currently only optical methods provide an acceptable solution, although there are a number of process layers and

The Art in Science of MicroTAS: the 2014 issue

April 14, 2015
Author(s)
Darwin R. Reyes-Hernandez
For the 7th year in a row the Art in Science award competition, sponsored by Lab on a Chip and the National Institute of Standards and Technology (NIST), took place at the 18th International Conference of Miniaturized Systems for Chemistry and Life

Thermal Effects on Critical Flow Venturis

April 14, 2015
Author(s)
John D. Wright, Aaron N. Johnson, Michael R. Moldover, Woong Kang, Liang Zhang
Critical flow venturis (CFVs) are widely used as working and transfer standards for gas flow measurement because of their long-term calibration stability (5 (e.g., a 2 mm throat diameter flowing air at 1 MPa), CFVs exhibit sensitivity to the environmental

A New Modem for Two Way Satellite Time and Frequency Transfer

April 13, 2015
Author(s)
Shengkang Zhang, Xueyun Wang, Haifeng Wang, Hongbo Wang, Yuan Yuan, Keming Feng
Two Way Satellite Time Frequency Transfer (TWSTFT) is a highly precise time & frequency remote comparison technique, which is widely used in time metrology, satellite navigation, etc. Nowadays, most of the time metrology laboratories in Europe, America and

An Analysis of the Use of a Collaboration Tool in the Intelligence Community

April 13, 2015
Author(s)
Jean C. Scholtz, Emile L. Morse, Michelle P. Steves
In this paper we present a broad look at the use of Groove as a collaboration tool in the analytic community. This work was carried out through the Research Development and Experimental Collaboration program (RDEC). The goal of this program is to bring

Bias Corrections in Primary Frequency Standards

April 13, 2015
Author(s)
Steven R. Jefferts, F Levi
Corrections to Primary Frequency Standards (PFS) or Secondary Frequency Standards (SFS) for offsets caused by various physical phenomena, e.g. Zeeman shifts or Blackbody radiation shifts, are typically corrected using formulae that contain “known”

Bias Corrections in Primary Frequency Standards

April 13, 2015
Author(s)
Thomas E. Parker, Thomas P. Heavner, Steven R. Jefferts
Primary frequency standards serve the function of calibrating the rate of International Atomic Time, TAI, and therefore play a critical role in the accuracy of the world's time. The Working Group on Primary and Secondary Frequency Standards, WGPSFS, is an

Configurable Robotic Millimeter-Wave Antenna Facility

April 13, 2015
Author(s)
Jeffrey R. Guerrieri, Joshua A. Gordon, David R. Novotny, Michael H. Francis, Ronald C. Wittmann, Miranda L. Butler
This paper introduces the Configurable Robotic Millimeter-Wave Antenna (CROMMA) facility by the Antenna Metrology Lab at the National Institute of Standards and Technology (NIST). NIST set out to develop an antenna measurement facility that would be

Constraint Handling In Combinatorial Test Generation Using Forbidden Tuples

April 13, 2015
Author(s)
Raghu N. Kacker, David R. Kuhn, Yu Lei
Constraint handling is a challenging problem in combinatorial test generation. In general, there are two ways to handle constraints, i.e., constraint solving and forbidden tuples. In our early work we proposed a constraint handling approach based on

Improving IPOGs Vertical Growth Based on a Graph Coloring Scheme

April 13, 2015
Author(s)
Raghu N. Kacker, David R. Kuhn, Yu Lei
In this paper, we show that the vertical growth phase of IPOG is optimal for t-way test generation when t = 2, but it is no longer optimal when t is greater than 2. We present an improvement that reduces the number of tests generated during vertical growth

Long-Term Uncertainty in Time Transfer Using GPS and TWTFT Techniques

April 13, 2015
Author(s)
Victor S. Zhang, Thomas E. Parker, Jian Yao
The techniques of GPS time and frequency transfer (code based and carrier phase) and two-way satellite time and frequency transfer (TWSTFT) are widely used in remote clock comparison and in the computation of International Atomic Time (TAI). Many timing

Nearly-linear light cones in long-range interacting quantum systems

April 13, 2015
Author(s)
Michael S. Foss-Feig, Zhexuan Gong, Charles W. Clark, Alexey V. Gorshkov
In non-relativistic quantum theories with short-range Hamiltonians, a velocity $v$ can be chosen such that the influence of any local perturbation is approximately confined to within a distance $r$ until a time $t \sim r/v$, thereby defining a linear light

NIST's Fully Dynamic Gravimetric Liquid Flowmeter Standard.

April 13, 2015
Author(s)
Jodie G. Pope, Aaron N. Johnson, Bernard J. Filla, Joey T. Boyd, Vern E. Bean, Christopher J. Crowley
We describe a new dynamic, gravimetric, liquid flow standard (LFS) that determines flow by measuring the rate of change of the liquid mass accumulating in a collection tank. The LFS is a fully- automated,15 kg/s system that uses a proportional–integral
Displaying 18276 - 18300 of 73929
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