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NIST Authors in Bold

Displaying 25951 - 25975 of 73871

Measuring Scale Errors in a Laser Tracker s Horizontal Angle Encoder through Simple Length Measurement and Two-face System Tests

November 1, 2010
Author(s)
Balasubramanian Muralikrishnan, Christopher J. Blackburn, Daniel S. Sawyer, Steven D. Phillips, Robert Bridges, Quan Ma
We describe a method to estimate the scale errors in the horizontal angle encoder of a laser tracker in this paper. The method does not require expensive instrumentation such as a rotary stage or even a calibrated artifact. An uncalibrated but stable

Noise-Parameter Measurements with a Reflection Type Phase Shifter

November 1, 2010
Author(s)
Dazhen Gu, Dave K. Walker, James P. Randa
We report a miniaturized phase shifter operating in the frequency range from 5 GHz to 7 GHz for noise-parameter extraction. Such a tunable solid-state unit represents a significant reduction in the size and mass as a source-pull component, compared to its

Optical fiber power meter comparison between NIST and NIM

November 1, 2010
Author(s)
Igor Vayshenker, Jian Li, L. M. Xiong, Z. X. Zhang, David J. Livigni, Xiaoyu X. Li, John H. Lehman
We describe the results of a comparison of reference standards between the National Institute of Standards and Technology (NIST-USA) and National Institute of Metrology (NIM-China). We report optical fiber-based power measurements at nominal wavelengths of

A New Call Admission Control Scheme for Heterogeneous Wireless Networks

October 31, 2010
Author(s)
Duk Kyung Kim, David W. Griffith, Nada T. Golmie
Call admission control between heterogeneous networks,such as an integrated 3GPP LTE and WLAN network, plays an important role to utilize the system resources in a more efficient way. In this paper, we propose that the preference to the WLAN is determined

The use of filtered photodetectors for radiance measurement

October 31, 2010
Author(s)
Albert C. Parr, B. Carol Johnson
A methodology for using a calibrated filter radiometer to measure and monitor the spectral radiance of calibration sources is described. An example using a calibration sphere used by NIST for its remote sensing program is presented.

An Advanced Patient Lift and Transfer Device for the Home

October 29, 2010
Author(s)
Roger V. Bostelman, Ji-Chul Ryu, Tommy Chang, Joshua Johnson, S K. Agrawal
The Home Lift, Position and Rehabilitation (HLPR) Chair has a unique design and novel capabilities when compared to conventional powered wheelchairs. In addition to mobility, it provides lift and can transfer patients. Even though medical devices are

Electrochemical measurement of diffusion in photopolymerized polyethylene glycol (PEG) hydrogels

October 29, 2010
Author(s)
Kavita M. Jeerage, Stephanie M. LaNasa, Holly A. Hughes, Damian S. Lauria, Stephanie J. Bryant, Andrew J. Slifka
Scanning electrochemical microscopy has been used to examine the molecular transport properties of photopolymerized poly(ethylene glycol) (PEG) hydrogels having different mesh sizes. Both the molecular weight (508 Da or 3000 Da) of the PEG diacrylate

Electron Dynamics of Crystalline 4-He at High Pressures

October 29, 2010
Author(s)
Eric L. Shirley, H. K. Mao, Yang Ding, Peter Eng, Yong Q. Cai, Paul Chow, Yuming Xiao, Jinfu Shu, Russell J. Hemley, Chichang Kao, Wendy L. Mao
At high pressures, helium crystallizes as a unique insulator with the widest known electronic band gap. However, in the vicinity of the band gap and above, electronic excitations have been previously inaccessible to direct measurements. Using an optimized

On the Fracture Behavior of Nano-Layered Coatings Under Tension.

October 29, 2010
Author(s)
Daniel Josell, Herzl Chai
In this work the fracture behavior of a model brittle/ductile (Si/Ag) multilayer evaporated on a thick substrate is studied with the aid of a four-point bending apparatus. The system variables include individual layer thickness (2.5 to 30 nm), total film

Residential Heat Pump Heating Performance with Single Faults Imposed

October 29, 2010
Author(s)
William V. Payne, Piotr A. Domanski, Seok Ho Yoon
A heat pump equipped with a thermostatic expansion valve (TXV) was tested in environmental chambers during steady-state no-fault and imposed-fault operation. The studied system was an R410A split residential heat pump with an 8.8 kW nominal cooling

10 Volt Programmable Josephson voltage standard circuits using NbSi-barrier junctions

October 28, 2010
Author(s)
Paul D. Dresselhaus, Mike Elsbury, David I. Olaya, Charles J. Burroughs, Samuel P. Benz
Programmable Josephson voltage standard (PJVS) circuits were developed that operate at 16 GHz to 20 GHz with operating margins larger than 1 mA. Two circuit designs were demonstrated each having a total of ~ 300,000 junctions, which were divided into

A comprehensive analysis of the spectrum of Fe II

October 28, 2010
Author(s)
Gillian Nave
A new analysis of the laboratory spectrum of Fe II is described. The aim is to produce a comprehensive list of Fe II lines, based on high-resolution grating and Fourier transform spectra, covering wavelengths from 900 ̊A to 5.5 μm. Particular attention has
Displaying 25951 - 25975 of 73871
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