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Displaying 31401 - 31425 of 74084

Slab-coupled optical waveguide devices for low-noise signal generation

July 23, 2007
Author(s)
Paul W. Juodawlkis, Frederick J. O'Donnell, Jason J. Plant, John B. Schlager
We review the use of slab-coupled optical waveguide amplifiers (SCOWAs) in low-noise mode-locked and single-frequency lasers. We also report a new single-frequency laser cavity incorporating an Er/Yb-codoped waveguide distributed Bragg-reflector that

Voltage Instability in a Simulated Fuel Cell Stack Correlated to Cathode Water Accumulation

July 22, 2007
Author(s)
Jon P. Owejan, T Trabold, Jeffrey J. Gagliardo, Robert N. Carter, Daniel S. Hussey, David L. Jacobson, Muhammad D. Arif
Single fuel cells running independently are often used for fundamental studies of water transport. It is also necessary to assess the dynamic behavior of fuel cell stacks comprised of multiple cells arranged in series, thus providing many paths for flow of

Low-noise fiber-laser frequency combs

July 19, 2007
Author(s)
Nathan R. Newbury, William C. Swann
We discuss experimental and theoretical aspects of a low-noise fiber-laser frequency comb, including the experimental configuration and the major contributions to the frequency noise and linewidth of the individual comb modes. Intra-cavity noise sources

Verification, Validation, and Variability of Virtual Standards

July 18, 2007
Author(s)
Dale P. Bentz
As the potential of computer modeling of hydration and microstructure development of cement-based materials approaches realization, the development of virtual standard test methods becomes a viable possibility. In creating these virtual standards, just as

Bias and the Limits of Pooling for Large Collections

July 17, 2007
Author(s)
C E. Buckley, Darrin L. Dimmick, Ian Soboroff, Ellen M. Voorhees
Modern retrieval test collections are built through a process called pooling in which only a sample of the entire document set is judged for each topic. The idea behind pooling is to find enough relevant documents such that when unjudged documents are

Border Gateway Protocol Security

July 17, 2007
Author(s)
D. Richard Kuhn, Kotikalapudi Sriram, Douglas Montgomery
This document introduces the Border Gateway Protocol (BGP), explains its importance to the internet, and provides a set of best practices that can help in protecting BGP. Best practices described here are intended to be implementable on nearly all

Impedance Measurements of Inertance Tubes at High Frequency and Pressure

July 16, 2007
Author(s)
Michael A. Lewis, Ryan P. Taylor, Peter E. Bradley, Ray Radebaugh, Gershon Grossman, Zhihua Gan
Previous comparisons between measured and calculated inertance tube impedance were made at frequencies below 70 Hz and average pressures below 3 MPa. In this paper, we present results on similar comparisons for frequencies up to 150 Hz and average

Model, Prediction and Experimental Verification of Composition and Thickness in Continuous Spread Thin Film Combinatorial Libraries Grown by Pulsed Laser Deposition

July 16, 2007
Author(s)
Nabil Bassim, Peter K. Schenck, Makoto Otani, Hiroyuki Oguchi
Pulsed laser deposition (PLD) is a powerful technique for growing continuous spread thin film libraries of continuously varying composition as a function of position on a substrate. Continuous spread thin film libraries are grown by striking a ceramic

MODELING AND EXPERIMENTS ON FAST COOLDOWN OF A 120 Hz PULSE TUBE CRYOCOOLER

July 16, 2007
Author(s)
Srinivas Vanapalli, Michael A. Lewis, Gershon Grossman, Zhihua Gan, Ray Radebaugh, H.J. M. ter Brake
High frequency operation of a pulse tube cryocooler leads to reduced regenerator volume, which results in a reduced heat capacity and a faster cooldown time. A pulse tube cryocooler operating at a frequency of 120 Hz and an average pressure of 3.5 MPa

A Virtual Rapid Chloride Permeability Test

July 15, 2007
Author(s)
Dale P. Bentz
The rapid chloride permeability test (RCPT), as it is commonly called, has been in existence for over 20 years and was standardized by ASTM over 15 years ago. The test is used extensively in the concrete industry for assessing concrete quality and is now

Analysis of Welding Parameter Distribution in Stud Arc Welding

July 15, 2007
Author(s)
Ivan Samardzic, Stefanija Klaric, Thomas A. Siewert
This paper describes the application of on-line monitoring system for recording welding current and voltage during stud arc welding with a ceramic ferrule. Recorded values of welding current and voltage are analyzed off-line for the weld process with both

ILThermo: A Free-Access Web Database for Thermodynamic Properties of Ionic Liquids

July 15, 2007
Author(s)
Qian Dong, Chris D. Muzny, Andrei F. Kazakov, Vladimir Diky, Joe W. Magee, Jason A. Widegren, Robert D. Chirico, Kenneth N. Marsh, Michael D. Frenkel
The development, scope, and functionality of the web-based ionic liquids database, ILThermo, are described. The database is available free to the public, and aims to provide users worldwide with up-to-date information from publications of experimental

RoHS Harmonization - Progress Toward a Single Global Standard?

July 13, 2007
Author(s)
Eric D. Simmon
The lack of global harmonization of RoHS initiatives has been a major headache for the electronics industry, to say the least. A number of organizations have been working very diligently to move standards closer together, with the hope that at some point

Scattering and Interference in Epitaxial Graphene

July 13, 2007
Author(s)
Gregory M. Rutter, Jason Crain, T Li, P First, Joseph A. Stroscio
A single sheet of carbon, graphene, exhibits unexpected electronic properties that arise from quantum state symmetries, which restrict the scattering of its charge carriers. Understanding the role of defects in the transport properties of graphene is

Color Rendering

July 11, 2007
Author(s)
Yoshihiro Ohno
LED technologies are advancing at a swift pace and solid-state lighting (SSL) products are already introduced to the market and expected to grow rapidly. There is an increasing interest and concern in the color rendering properties of white SSL products
Displaying 31401 - 31425 of 74084