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Search Publications

NIST Authors in Bold

Displaying 32701 - 32725 of 73929

Development of an Experimental Database and Kinetic Models for Surrogate Diesel Fuels

April 16, 2007
Author(s)
J T. Ferrell, N Cernansky, F L. Dryer, Daniel G. Friend, C A. Hergart, C K. Law, R M. McDavid, Christian Mueller, A K. Patel, Heinz Pitsch
Computational fluid dynamic (CFD) simulations that include realistic combustion/emissions chemistry hold the promise of significantly shortening the development time for advanced, high efficiency, low emission engines. However, significant challenges must

Performance of Biometric Quality Measures

April 16, 2007
Author(s)
Patrick Grother, Elham Tabassi
We document methods for the quantitative evaluation of systems that produce a scalar summary of a biometric sample¿s quality. We predicate this on the idea that the quality measure predicts performance, whether by design or correlation. We do this

Conservative Confidence Intervals Based on Weighted Means Statistics

April 15, 2007
Author(s)
Andrew L. Rukhin
For weighted means estimators of the common mean of several normal populations associated (conservative) confidence intervals are constructed. These intervals are compared to several traditional confidence bounds. Monte Carlo simulation results of these

Cancellation of the Collisional Frequency Shift in Caesium Fountain Clocks

April 13, 2007
Author(s)
K Szymaniec, W Chalupczak, Eite Tiesinga, Carl J. Williams, S Weyers, R. Wynands
We have observed that the collisional frequency shift in primary caesium fountain clocks varies with the clock state population composition and, in particular, is zero for a given fraction of the |F = 4, mF = 0> atoms, depending on the initial cloud

Synthesis and Single-Crystal X-Ray Diffraction Studies of New Framework Substituted Type II Clathrates, Cs 8 Na 16 Ag x Ge 136-x (x 7)

April 13, 2007
Author(s)
Matthew Beekman, Winnie Wong-Ng, James A. Kaduk, Alexander J. Shapiro, George S. Nolas
New inorganic type II clathrates with Ag atoms substituting for framework Ge atoms, Cs8Na16AgxGe136-x (x = 0, 5.9, and 6.7), have been synthesized by reaction of the pure elements at high temperature. Structural refinements have been performed using single

A Study of the Packing Density and Molecular Orientation of Bimolecular Self-Assembled Monolayers of Aromatic and Aliphatic Organosilanes on Silica

April 12, 2007
Author(s)
M B. Smith, K Efimenko, Daniel A. Fischer, S E. Lappi, P E. Kilpatrick, Jan Genzer
Bimolecular self-assembled monolayers (SAMs) of aromatic and aliphatic chlorosilanes were self-assembled onto silica and their characteristics were established by contact angle measurement, near-edge X-ray adsorption fine structure spectroscopy, and

Machine Shop Information Model Application, Next Step

April 11, 2007
Author(s)
Yung-Tsun Lee, Yan Luo
Simulation is defined as the imitation of the operation of a system or real-world process over time, and in many cases, manufacturing provides one of the most important applications of simulation (Zolfaghari and Roa, 2006). Standard interfaces could make

Nonthermal continuum toward Sagittarius B2(N-LMH)

April 11, 2007
Author(s)
J M. Hollis, P R. Jewell, A Remijan, Francis J. Lovas
An analysis of continuum antenna temperatures observed in theGBTspectrometer bandpasses is presented for observations toward Sgr B2(N-LMH). Since 2004, we have identified four new prebiotic molecules toward this source by means of rotational transitions

Particle and Photon Detection for a Neutron Radiative Decay Experiment

April 11, 2007
Author(s)
Thomas R. Gentile, Maynard S. Dewey, Hans P. Mumm, Jeffrey S. Nico, Alan K. Thompson, T E. Chupp, R Cooper, B M. Fisher, I Kremsky, F E. Wietfeldt, K G. Kiriluk, E Beise
We present the particle and photon detection methods employed in a program to observe neutron radiative beta-decay. The experiment is located at the NG-6 beam line at the National Institute of Standards and Technology Center for Neutron Research. Electrons

Towards Industrial Scale Fabrication of Nanowire-Based Devices

April 11, 2007
Author(s)
Babak Nikoobakht
The key requirements for mass fabrication of nanodevices are directed positioning and alignment of nanoparticles (e.g., nanowires) with known registries on a large scale. Here, these issues are addressed in a high throughput and scalable approach for

Objective Test and Performance Measurement of Automotive Crash Warning Systems

April 10, 2007
Author(s)
Sandor S. Szabo, Richard J. Norcross, Joseph A. Falco
The National Institute of Standards and Technology (NIST), under an interagency agreement with the United States Department of Transportation (USDOT), is supporting development of objective test and measurement procedures for vehicle-based warning systems

Traceable Micro-Force Sensor for Instrumented Indentation Calibration

April 10, 2007
Author(s)
Douglas T. Smith, Gordon A. Shaw, R M. Seugling, D Xiang, Jon R. Pratt
Instrumented indentation testing (IIT), commonly referred to as nanoindentation when small forces are used, is a popular technique for determining the mechanical properties of small volumes of material. Sample preparation is relatively easy, usually

Training and Optimization of Operating Parameters for Flash LADAR Cameras

April 10, 2007
Author(s)
M Price, J Kenney, Roger D. Eastman, Tsai H. Hong
Flash LADAR cameras based on continuous-wave, time-of-flight range measurement deliver fast 3D imaging for robot applications including mapping, localization, obstacle detection and object recognition. The accuracy of the range values produced depends on

Broaband THz aqueous blackbody calibration source

April 9, 2007
Author(s)
Charles Dietlein, Zoya Popovic, Erich N. Grossman
We describe a broadband calibration source for the millimeter-wave to terahertz (THz) frequency range, the Aqueous Blackbody Calibration (ABC) source. The blackbody in this design is a body of water, which is extremely absorptive at these frequencies, held

Performance comparison of Nb and NbN antenna-coupled microbolometers

April 9, 2007
Author(s)
Charles Dietlein, A. Luukanen, J. S. Penttila, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, Erich N. Grossman
We report the experimental results of a comparison between free-standing Nb and NbN microbolometer bridges coupled to equiangular spiral antennas on Si substrates. Because of the difference in material resistivity, bolometer resistance and aspect ratio is

Spectral decomposition of ultra-wide-band terahertz imagery

April 9, 2007
Author(s)
Erich N. Grossman, Charles Dietlein, Jonathan Chisum, A. Luukanen, J. E. Bjarnason, E. R. Brown
We investigate the spectral response of a THz imaging system based on ultrawideband cryogenic microbolometers. The bandwidth if this system, nominally 0.2 - 1.8 THz, is broad enough to span large variations (>10 dB) in clothing transmittance and
Displaying 32701 - 32725 of 73929
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