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Displaying 32476 - 32500 of 73960

Frequency Comparison of Al + and Hg + Optical Standards

June 24, 2007
Author(s)
Till P. Rosenband, David Hume, Anders Brusch, Luca Lorini, P. O. Schmidt, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, W Swann, Windell Oskay, Wayne M. Itano, David J. Wineland, James C. Bergquist
We compare the frequencies of two single ion frequency standards: 27Al + and 199Hg +. Systematic fractional frequency uncertainties of both standards are below 10 -16, and the statistical measurement uncertainty is below 5 x 10 -17. Recent ratio

Frequency-Tunable Josephson Junction Resonator for Quantum Computing

June 23, 2007
Author(s)
Kevin Osborn, Joshua Strong, Adam J. Sirois, Raymond W. Simmonds
We have fabricated and measured a high-Q Josephson junction resonator with a tunable resonance frequency. A dc magnetic flux allows the resonance frequency to be changed by over 10%. Weak coupling to the environment allows a quality factor of 7000 in the

ACJVS Operating Margins using a Ternary Arbitrary Bitstream Generator

June 22, 2007
Author(s)
Ernest Houtzager, Samuel Benz, Helko vanden Brom
In this paper we present measurements with a pulse-driven AC Josephson voltage standard (ACJVS) that uses a ternary arbitrary bitstream generator as the bias source. From these measurements we conclude that the circuit is operational for voltages up to 220

The Polarizability of Helium and Gas Metrology

June 22, 2007
Author(s)
James W. Schmidt, R Gavioso, E May, Michael R. Moldover
Using a quasi-spherical, microwave cavity resonator, we measured the refractive index of helium to deduce its molar polarizability A ε in the limit of zero density. We obtained (A ε,meas - A ε,theory)/A ε = (-1.8plus or minus} 8.4)× 10 -6, where the

Delamination strength of YBCO coated conductors under transverse tensile stress

June 21, 2007
Author(s)
Daniel C. van der Laan, John (Jack) W. Ekin, Cameron C. Clickner, Theodore C. Stauffer
We present a new experimental technique to measure the delamination strength under transverse tensile stress of YBa 2Cu 3O 7-δ coated conductors for electric power applications. The delamination strength, defined as the tensile stress at which the ceramic

Experimental Evaluation of SiC PiN Diode Forward Bias Degradation and Long Term Stability

June 21, 2007
Author(s)
Madelaine H. Hernandez, Adwoa Akuffo, Colleen E. Hood, Jose M. Ortiz, Allen R. Hefner Jr.
New automated metric systems and procedures have been developed and introduced in order to evaluate the long stability of SiC PiN diodes, and long term stability results are presented for 10 kV SiC PiN diodes that are made using a new low degradation

High-Voltage, High-Frequency SiC Power MOSFETs Model Validation

June 21, 2007
Author(s)
Jose M. Ortiz, Tam H. Duong, Angel Rivera-Lopez, Allen R. Hefner Jr.
Simulated results for techniques used to validate the on-state, resistive load switching, inductive load switching, and high voltage depletion capacitance performance for 4H-SiC power MOSFETs are presented. The validation is performed using a script

Role of Interfacial Water in the Adhesion Loss of Polymer/Substrate Systems and Composites

June 21, 2007
Author(s)
Tinh Nguyen, Joannie W. Chin, E Byrd, David Alshed, Cyril Clerici, Jonathan W. Martin
Water at the polymer/substrate interface in coatings, adhesives, and fiber-reinforced polymer composites is often the main cause of adhesion loss in these systems. Using experimental data measured in this study, we critically assess the role of interfacial

A Multi-Criteria Web Services Composition Problem

June 20, 2007
Author(s)
Jeong Buhwan, Hyunbo Cho, Boonserm Kulvatunyou, Albert W. Jones
With its prevalence in enterprise applications integration, the service-oriented approach has been studied in various ways. The popularity, however, results in a number of different standards and implementations. The approach needs agreed-upon definitions

Extending the Limits of Image-Based Optical Metrology

June 20, 2007
Author(s)
Richard M. Silver, Bryan M. Barnes, Ravikiran Attota, Jay S. Jun, Michael T. Stocker, Egon Marx, Heather J. Patrick
We have developed a set of techniques, referred to as scatterfield microscopy, in which the illumination is engineered in combination with appropriately designed metrology targets. Previously we reported results from samples with sub-50 nm sized features

Multifunctional ferrimagnetic-ferroelectric thin films for microwave applications

June 20, 2007
Author(s)
Ranko R. Heindl, S. Witanachchi, P. Mukherjee, A. Heim, G. Matthews, S. Balachandran, S. Natarajan, T. Weller
Ferrimagnetic and ferroelectric structures based on barium strontium titanate and barium hexaferrite are investigated for potential applications in tunable microwave devices. Thin film bilayers were grown on MgO and sapphire, and their underlying

Towards scaling up trapped ion quantum information processing

June 19, 2007
Author(s)
Dietrich G. Leibfried, David J. Wineland, Brad R. Blakestad, John J. Bollinger, Joseph W. Britton, J Chiaverini, Ryan Epstein, Wayne M. Itano, John D. Jost, Emanuel H. Knill, C. Langer, R Ozeri, Rainer Reichle, Signe Seidelin, Nobuyasu Shiga, Janus Wesenberg
Recent theoretical advances have identifed several computational algorithms that can be implemented utilizing quantum information processing (QIP), which gives an exponential speedup over the corresponding (known) algorithms on conventional computers. QIP

Tuning Polymer Melt Fragility With Antiplasticizer Additives

June 19, 2007
Author(s)
Robert A. Riggleman, Jack F. Douglas, J J. de Pablo
A polymer-diluent model exhibiting antiplasticization has beendeveloped and characterized by molecular dynamics simulations. Antiplasticizer molecules are shown to decrease the glass transition temperature Tg, but to increase the elastic moduli of the

High Contrast Scanning Nano-Raman Spectroscopy of Silicon

June 15, 2007
Author(s)
N Lee, R Hartschuh, D Mehtani, A Kisliuk, M D. Foster, Alexei Sokolov, J F. Maguire, Martin L. Green
We have demonstrated that scanning nano-Raman spectroscopy (SNRS), generally known as tip enhanced Raman spectroscopy (TERS), with side illumination optics can be effectively used for analysis of silicon based structures at the nanoscale. Even though the

Recent Developments of the HLPR Chair

June 15, 2007
Author(s)
Roger V. Bostelman, James S. Albus, Tommy Chang
The Home Lift, Position and Rehabilitation (HLPR) Chair, developed at the National Institute of Standards and Technology (NIST) within the Intelligent Systems Division (ISD) from 2005 to 2006, is currently being evaluated for static stability using

Urban Search and Rescue Robot Performance Standards: Progress Update

June 15, 2007
Author(s)
Adam S. Jacoff, Elena R. Messina
In this paper, we describe work in performance standards for urban search and rescue (US&R) robots, begun in 2004 by the Department of Homeland Security. This program is being coordinated by the National Institute of Standards and Technology and will
Displaying 32476 - 32500 of 73960
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