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NIST Authors in Bold

Displaying 29601 - 29625 of 74178

International comparisons of optical fiber power measurements

October 1, 2008
Author(s)
Igor Vayshenker, David J. Livigni, Xiaoyu X. Li, John H. Lehman
We discuss the results of optical fiber power meter (OFPM) measurements at 1302 and 1546 nm made by NIST and six national measurement institutes (NMIs). We also describe transfer standards and the associated uncertainties. The comparisons show a reasonably

Long-term Stability of the NIST Standard Ultrasonic Source

October 1, 2008
Author(s)
Steven E. Fick
The NIST Standard Ultrasonic Source (SUS) is a system comprising a transducer capable of output power levels up to 1 W at multiple frequencies between 1 MHz and 30 MHz, and an electrical impedance-matching network that allows the system to be driven by a

Modulus and Chemical Mapping of Multi-layer Coatings

October 1, 2008
Author(s)
Aaron M. Forster, Chris A. Michaels, Li Piin Sung, Justin Lucas
Thermoplastic olefins (TPO) are polymeric materials utilized for interior and exterior automotive parts. These materials are often painted to enhance appearance and protect the soft TPO substrate. TPO materials posses a low surface energy due to the

Neutron Scattering Study of the Excitation Spectrum of Solid Helium At Ultra-low Temperatures

October 1, 2008
Author(s)
Elizabeth Blackburn, John Goodkind, Sunil K. Sinha, Collin Broholm, John R. Copley, Ross W. Erwin
There has been a resurgence of interest in the properties of Solid Helium due to the recent discovery of non-classical rotational inertia (NCRI) in solid 4He by Chan and coworkers below 200 mK which they have interpreted as a transition to a "supersolid"

NEW PRACTICAL METHOD FOR MEASUREMENT OF HIGH-POWER LEDS

October 1, 2008
Author(s)
Yuqin Zong, Yoshihiro Ohno
The measurement of high-power light emitting diodes (LEDs) has been difficult because they are highly sensitive to thermal operating conditions, and there has been a lack of common methods that can be used by both LED manufactures and users to acquire

Recent atomic clock comparisions at NIST

October 1, 2008
Author(s)
Luca Lorini, Neil Ashby, Anders Brusch, Scott Diddams, Robert E. Drullinger, Eric Eason, Tara Fortier, Pat Hastings, Thomas P. Heavner, David Hume, Wayne M. Itano, Steven R. Jefferts, Nathan R. Newbury, Tom Parker, Till P. Rosenband, Jason Stalnaker, William C. Swann, David J. Wineland, James C. Bergquist
The record of atomic clock frequency comparisons at NIST over the past half-decade provides one of the tightest constraints of any present-day, temporal variations of the fundamental constants. Notably, the 6-year record of increasingly precise

Robustness of display hemispherical reflectance measurement apparatus

October 1, 2008
Author(s)
John Penczek, Edward F. Kelley, Seugkwan Kim
Reflection measurements are critical to the evaluation of display performance under ambient illumination conditions. Various hemispherical reflection methods are evaluated for their suitability and robustness across display technologies. The standard

Superfludity and phase transitions in a resonant Bose gas

October 1, 2008
Author(s)
Leo Radzihovsky, Peter B. Weichman, Jae Park
The atomic Bose gas is studied across a Feshbach resonance, mapping out its phase diagram, and computing its thermodynamics and excitation spectra. It is shown that such a degenerate gas admits two distinct atomic and molecular superfluid phases, with the

Using uncalibrated lasers as wavelength standards

October 1, 2008
Author(s)
Jack A. Stone Jr.
The fundamental atomic physics of a gas laser transition is such that the transition frequency, or equivalently, the vacuum wavelength of the laser, cannot vary from its central value by more than a few parts in 106. The uncertainty of the gas laser

Contaminant Accumulation and Removal in Building Plumbing Systems

September 30, 2008
Author(s)
Stephen J. Treado, Mark A. Kedzierski, Daniel R. Flynn, David Wilmering, Thomas D. Montgomery, Kenneth D. Cole
This report summarizes measurements and results conducted to evaluate the accumulation and removal of water-borne contaminants in building plumbing systems. In particular, tests were conducted at the BFRL Plumbing Test Facility, which emulates a full-scale

Investigations of a coherently driven semiconductor optical cavity QED system

September 30, 2008
Author(s)
Kartik A. Srinivasan, Christopher P. Michael, Raviv Perahia, Oskar Painter
Chip-based cavity QED devices consisting of a self-assembled InAs quantum dot (QD) coupled to a high quality factor GaAs microdisk cavity are coherently probed through the optical channel using a fiber taper waveguide. We highlight one particularly
Displaying 29601 - 29625 of 74178