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NIST Authors in Bold

Displaying 32551 - 32575 of 73960

Connecting the Dots

June 1, 2007
Author(s)
Stephen D. Quinn
Establishing traceability from high-level Federal Information Security Management Act (FISMA) requirements to specific mechanisms to secure hardware and software poses challenges for the government?s systems security managers. Effectively using security

Current Ripple Effect on n-Value

June 1, 2007
Author(s)
Loren F. Goodrich, Jolene Splett
We studied the systematic effect of current ripple on the determination of n-value, which is the index of the shape of the electric field-current (E-I) curve. Commercial Nb 3Sn wires were measured with controlled amounts of ac ripple. Substitution-box

Disorder effects on the intrinsic nonlinear current density in YBa2Cu3O7

June 1, 2007
Author(s)
Brian M. Andersen, James Booth, P.J. Hirschfeld
We present harmonic generation measurements of the intrinsic nonlinear current density j2 of (YBCO) films at temperatures close the Tc. Experiments on a range of different quality samples allow us to extract the dependence of j2 on the penetration depth of

Dynamic Phasor Measurement Unit Test System

June 1, 2007
Author(s)
Gerard N. Stenbakken, Ming Zhou
This paper presents the plans and progress towards the development of a dynamic phasor measurement unit (PMU) performance test system at NIST. We describe an algorithm for taking time-synchronized samples of single-phase voltage and current power signals

Effect of the Spherical Indenter Tip Assumption on Nanoindentation

June 1, 2007
Author(s)
Li Ma, Lyle E. Levine
Nanoindentation is increasingly being used to explore mechanical properties on a local scale. One of the interests and challenges of nanoindentation is determining the shear stress at the onset of plastic yielding, which corresponds to dislocation

Measurement of Weld Toughness - Crack Tip Opening Angle Criterion

June 1, 2007
Author(s)
Philippe P. Darcis, Joseph D. McColskey, Christopher N. McCowan, Thomas A. Siewert
The stable tearing behavior of X100 pipeline steel through a girth weld section was investigated using a modified double cantilever beam specimens. A test technique for direct measurement of the steady state crack tip opening angle (CTOA) criterion was

Numerical Fluorescence Correlation Spectroscopy for Molecular Dynamics Analyses Under Non-Standard Conditions

June 1, 2007
Author(s)
Michael J. Culbertson, Joshua T. Williams, Wayland Cheng, Dee A. Stults, Emily R. Wiebrach, John J. Kasianowicz, Daniel L. Burden
A major concern in Fluorescence Correlation Spectroscopy (FCS) pertains to the accuracy of standard mathematical models that are used to extract kinetic information from correlated data. The standard equations used in FCS arise from a simple Gaussian model

Observation of the 1 S 0 - 3 P 0 clock transition in 27 Al +

June 1, 2007
Author(s)
Till P. Rosenband, P. O. Schmidt, David Hume, Wayne M. Itano, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Jeroen Koelemeij, James C. Bergquist, David J. Wineland
We report for the first time, laser spectroscopy of the 1S 0 – 3P 0 clock transition in 27Al +. A single aluminum ion and a single beryllium ion are simultaneously confined in a linear Paul trap, coupled by their mutual Coulomb repulsion. This coupling

Optical and Structural Study of GaN Nanowires Grown by Catalyst-Free MBE: (II) Defect-Related Luminescence and Electron-Beam Irradiation Effects

June 1, 2007
Author(s)
Lawrence H. Robins, Kristine A. Bertness, John G. Barker, Norman A. Sanford, John B. Schlager
GaN nanowires grown by catalyst free molecular beam epitaxy were characterized by photoluminescence (PL) and cathodoluminescence (CL) spectroscopy at temperatures from 3 K to 295 K. Both as grown samples, which contained approximately vertically oriented

Quantum key distribution over a 40-dB channel loss using superconducting single-photon detectors

June 1, 2007
Author(s)
Hiroki Takesue, Sae Woo Nam, Qiang Zhang, Robert Hadfield, Toshimori Honjo, Kiyoshi Tamaki, Yoshihisa Yamamoto
We report the first quantum key distribution (QKD) experiment to enable the creation of secure keys over 42 dB channel loss and 200 km of optical fibre. We used the differential phase shift QKD (DPS-QKD) protocol, implemented with a 10-GHz clock frequency

Spotlighting NIST Standard Reference Materials - New Standard Reference Material (SRM) 2585 Organic Contaminants in House Dust to Support Exposure Assessment Measurements

June 1, 2007
Author(s)
Michele M. Schantz, Jennifer M. Lynch, John R. Kucklick, Dianne L. Poster, H M. Stapleton, S S. Vander Pol, Stephen A. Wise
House dust originates from both internal and external sources and has been identified as one of the primary sources of lead exposure for children (http://www.epa.gov/lead). House dust is also a repository for pesticides, flame retardants, and other

Static Calibration and Dynamic Characterization of PMUs at NIST

June 1, 2007
Author(s)
Gerard N. Stenbakken, Thomas L. Nelson
This paper describes the development of two test systems at NIST aimed at improving the calibration and characterization of Coordinated Universal Time (UTC) synchronized electric power instrumentation. Reference to UTC is used to meet the need for precise
Displaying 32551 - 32575 of 73960
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