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Displaying 37951 - 37975 of 74035

Physics-Based Modeling of Community Fires

July 7, 2004
Author(s)
D D. Evans, Ronald G. Rehm, Elisa S. Baker, E G. McPherson, Jeffrey B. Wallace
Physics-based modeling of fires in the wildland urban interface (WUI) is used to develop practical tools for fire hazard evaluation of landscaped properties. The approach differs from that used for wildland-fire operation models in that individual fuel

RCS: A Cognitive Architecture for Intelligent Multi-Agent Systems

July 7, 2004
Author(s)
James S. Albus, Tony Barbera
RCS (Real-time Control System) is a cognitive architecture designed to enable any level of intelligent behavior, up to and including human levels of performance. RCS was inspired 30 years ago by a theoretical model of the cerebellum, the portion of the

Simulating the Fires in the World Trade Center

July 7, 2004
Author(s)
Kevin B. McGrattan, C P. Bouldin
The National Institute of Standards and Technology (NIST) is conducting a two year investigation of the World Trade Center disaster. Among numerous tasks, computer simulations of the fires are being conducted to provide structural engineers with a detailed

The Basis for Egress Provisions in U.S. Building Codes

July 7, 2004
Author(s)
Richard W. Bukowski, Erica D. Kuligowski
Some of the earliest public safety-from-fire regulations in the US are requirements for egress stairs adopted by New York City in 1860 . One of the first model regulations promulgated by the National Fire Protection Association (NFPA) was the 1927 Building

Urban/Widlland Fires: Ignition by Embers

July 7, 2004
Author(s)
Samuel L. Manzello, Thomas G. Cleary, Jiann C. Yang
Urban-wildland fires have plagued the United States for centuries. Embers are produced as trees and other objects burn in urban-wildland fires. These embers are entrained in the atmosphere and may be carried by winds over long distances. Hot embers

Superconducting transition edge sensor using dilute AlMn alloys

July 6, 2004
Author(s)
Steven Deiker, William B. Doriese, Gene C. Hilton, Kent D. Irwin, William H. Rippard, Joel N. Ullom, Leila R. Vale, Steve T. Ruggiero, Anthony Williams, B. Young
We have fabricated a bolometer using a transition-edge sensor (TES) made of Al doped with Mn to suppress the superconducting critical temperature !Tc" of Al from #1 K to #100 mK. The resulting detector exhibits low-frequency noise consistent with theory

In-situ observation of nano-oxide formation in magnetic thin films

July 4, 2004
Author(s)
Andrew McCallum, Stephen E. Russek
In situ conductance and reflected high energy electron diffraction (RHEED) measurements were taken during the oxidation of 20-nm-thick Co and CoFe layers. The conductance shows an initial drop with exposure to oxygen followed by a period of increasing

Structure and Magnetic Switching of Thin Film HITPERM/SiO 2 Soft Magnetic Multilayers

July 4, 2004
Author(s)
Hideyuki Okumura, C Y. Um, S Y. Chu, M E. McHenry, D E. Laughlin, Anthony B. Kos
Laminated (Fe 0.7Co 0.3) 88Zr 7B 4Cu a-HITPERM/SiO 2 multilayer thin films have been previously shown to exhibit thermally activated, stepped magnetization curves associated with sequential switching of layers. A model for the thickness dependence of the

Linking Microwave Remote Sensing Measurements to Fundamental Noise Standards

July 2, 2004
Author(s)
James P. Randa, Dave K. Walker, Michael H. Francis
We outline the formalism for linking microwave remote-sensing measurements to fundamental noise standards and estimate the achievable uncertainty. Plans for the development and use of standard radiometers for this purpose are presented.

Modeling of Magnetization and Demagnetization in Magnetic Regenerative Refrigeration

July 2, 2004
Author(s)
F Shir, Edward Della Torre, Lawrence H. Bennett, C Mavriplis, Robert D. Shull
A time-dependent model of magnetization and demagnetization temperature profile is developed based on thermodynamic and heat transfer laws, material properties, and variable-field magnet parameters. Test results of a magnetic refrigeration test bed

Modeling Warm-Up Drift in Commercial Harmonic Phase Standards

July 2, 2004
Author(s)
Jeffrey Jargon, Jolene Splett, Dominic F. Vecchia, Donald C. DeGroot
We develop an empirical model for the warm-up drift of harmonic phase standards that are used to calibrate the phase distortion of nonlinear vector nrtworks analyzers. This model will enable us to estimate the time at which the standards reach stability.

Advanced Techniques for Nanocharacterization of Polymeric Coating Surfaces

July 1, 2004
Author(s)
Xiaohong Gu, Tinh Nguyen, Li Piin Sung, Mark R. VanLandingham, Y C. Jean, Jonathan W. Martin
The applications of AFM and nanoindentation on study of surface property of polymeric coatings have been demonstrated. The surface microstructure of several coatings was characterized using tapping mode AFM, and the morphological change of coatings during

An Uncertainty Analysis of a NIST Hydrocarbon Liquid Flow Calibration Facility

July 1, 2004
Author(s)
Tsyh Tyan Yeh, Pedro I. Espina, G E. Mattingly, N Briggs, Jesus J. Aguilera
The paper presents the uncertainty characterization of NIST s new hydrocarbon liquid calibrator (HLFC). This facility uses a passive piston prover technique where fluid is driven by pumps while the measuring piston is passively stroked through the

Applications of Sinkhorn Balancingto Counting Problems

July 1, 2004
Author(s)
Isabel M. Beichl, F Sullivan
We describe a gneral Monte Carlo technique based on work of Knuth for estimating the size of trees in backtrack algorithms. This method, based on importance sampling, is used to estimate the number of partial and complete matchings in a bipartite graph

Aqueous Solubility of Volatile Nonelectrolytes

July 1, 2004
Author(s)
Allan H. Harvey, M T. Fernandez-Diaz, J L. Alvarez
The thermodynamics of solution of voletile cormponents in water is reviewed and expressed both in terms of the Henry's constant and the vapor-liquid distribution coefficient. The procedures required to calculate these quantities from experimental data are
Displaying 37951 - 37975 of 74035