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Search Publications

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Displaying 35001 - 35025 of 74229

Experience in the Exchange of Procedural Shape Models Using ISO 10303 (STEP)

March 30, 2006
Author(s)
Mike Pratt, Junhwan Kim
The international standard ISO 10303 (STEP) is being extended to permit the exchange of procedurally defined shape models, with additional parameterization and constraint information, between CAD systems. The transfer of parameterized assembly models is an

Large-angle magnetization dynamics measured by time-resolved ferromagnetic resonance

March 30, 2006
Author(s)
Thomas Gerrits, Michael Schneider, Anthony B. Kos, Thomas J. Silva
A time-resolved ferromagnetic resonance technique was used to investigate the nonlinear magnetization dynamics of a 10 nm thin Permalloy TM film in response to a sequence of large-amplitude field pulses. The magnetic field pulse sequence was set at a

One-Laser Interferometric Broadband Coherent Anti-Stokes Raman Scattering

March 30, 2006
Author(s)
T W. Kee, Hongxia (Jessica) Zhao, Marcus T. Cicerone
We introduce an interferometric technique for eliminating the nonresonant background of broadband coherent anti-Stokes Raman scattering (CARS) microscopy. CARS microscopy has been used for imaging a number of biological samples and processes, but the

Ionizing Radiation-Induced Destruction of Benzene and Dienes in Aqueous Media

March 28, 2006
Author(s)
M I. Al-Sheikhly, Dianne L. Poster, Jung-Chul An, Pedatsur Neta, Joseph Silverman, Robert E. Huie
Pulse radiolysis with spectrophotometric and conductometric detection was utilized to study the formation and reactions of radicals from benzene and dienes in aqueous solutions. The benzene OH adduct, C6H6OH, reacts with O2 (k = 3 x 108 L mol-1 s-1) in a

A Compact High Stability Optical Clock Based on Laser-Cooled Ca

March 27, 2006
Author(s)
Christopher W. Oates, Yann LeCoq, G Wilpers, Leo W. Hollberg
We report new measurements and modifications for a simple, compact, Ca atomic clock at 657 nm. External measurements were made against an independent Yb lattice optical clock via a fs-laser frequency comb. These results lead to upper limits of the Ca clock

Atom-based stabilization for laser-pumped atomic clocks

March 27, 2006
Author(s)
Vladislav Gerginov, V Shah, Svenja A. Knappe, Leo W. Hollberg, John E. Kitching
Progress towards simplification and improvement of the long-term stability of chip-scale atomic clocks is presented. The conventional technique of laser optical frequency and cell temperature control is compared with a novel technique which avoids the use

Blackbody radiation shift of the 27 Al + 1 S 0 - 3 P 0 transition

March 27, 2006
Author(s)
Till P. Rosenband, Wayne M. Itano, Piet Schmidt, David Hume, Jeroen Koelemeij, James C. Bergquist, David J. Wineland
The differential polarizability, due to near-infrared light at 1126 nm, of the 27Al + 1S 0 – 3P 0 transition is measured to be {Δ}α = (1.6 ± x 10 -31 m 3, where {Δ}α = α P - α S is the difference between the excited and ground state polarizabilities. This

Dietary Supplement Standard Reference Materials

March 27, 2006
Author(s)
Lane C. Sander, Katherine E. Sharpless, Stephen A. Wise
A new category of Standard Reference Materials based on dietary supplements are under development by NIST, with certified values for organic constituents and selected trace elements. These materials are provided primarily for use in method development and

New Industry Requirements for Clock Synchronization and Time Stamping

March 27, 2006
Author(s)
Harvey Wohlwend, Ya-Shian Li-Baboud
This presentation will report on the results of an industry working group studying time synchronization. The working group will present new industry requirements as well as guidelines for improving time synchronization and time stamping. Efficient

Power Dependence of the Shift Caused by Spurious Spectral Components in Atomic Fountain

March 27, 2006
Author(s)
Filippo Levi, Jon H. Shirley, Thomas P. Heavner, Dai Yu, Steven R. Jefferts
In this paper we analyze the behavior of the frequency shift caused by spurious spectral component in the microwave spectrum against variation of the excitation microwave field. The theory of the shift caused by the presence of spurs in the microwave

Spectroscopy of neutral 174 Yb in a one-dimensional optical lattice

March 27, 2006
Author(s)
C Hoyt, Zeb Barber, Christopher W. Oates, A. V. Taichenachev, V. I. Yudin, Leo W. Hollberg
We report spectroscopy of the 1S 0 - 3P 0 clock transition in neutral 174Yb atoms confined to a one- dimensional optical lattice at the ac Stark shift-canceling wavelength of 759.35 nm. Spectroscopic linewidths as narrow as 4 Hz, full width at half-maximum

Failure of Glass Layers on Polymeric Substrates From Vickers Indentation

March 25, 2006
Author(s)
Herzl Chai, Brian R. Lawn
A study is made of median crack evolution in brittle coatings subjected to sharp contacts. A model bilayer system consisting of a glass plate bonded to a polycarbonate base, with a Vickers pyramid as indenter, is used to demonstrate the evolution in situ

Bias Reduction in Roughness Measurement through SEM Noise Removal

March 24, 2006
Author(s)
R Katz, C D. Chase, R Kris, R Peltinov, John S. Villarrubia, B Bunday
The importance of Critical Dimension (CD) roughness metrics such as Line and Contact edge roughness (LER, CER) and their associated width metrics (LWR, CWR) have been dealt with widely in the literature and are becoming semiconductor industry standards

Sub-micron gap capacitor for measurement of breakdown voltage in air

March 24, 2006
Author(s)
Emmanouel S. Hourdakis, Brian Simonds, Neil M. Zimmerman
We have developed a new method for measuring the value of breakdown voltage in air for electrode separations from 400 nm to 45 'm. The electrodes used were thin film Au lines evaporated on sapphire. The resulting capacitors had an area of 80 'm by 80 'm

Hyperspectral Image Projectors for Radiometric Applications

March 23, 2006
Author(s)
Joseph P. Rice, Steven W. Brown, Bettye C. Johnson, Jorge E. Neira
We describe a new type of Calibrated Hyperspectral Image Projector (CHIP) intended for radiometric testing of instruments ranging from complex hyperspectral or multispectral imagers to simple filter radiometers. The CHIP, based on the same digital mirror

Inside Diameter Measurements for the Cylinder of a 20 L Piston Prover

March 23, 2006
Author(s)
Jesus J. Aguilera, Tsyh Tyan Yeh, John D. Wright
We made inside diameter measurements of a stainless steel cylinder used in a piston prover for hydrocarbon liquid flow measurements. We used a 3-point micrometer and two traceable setting rings to measure diameter at 12 radial positions at each of 21

Low Background Temperature Calibration of Infrared Blackbodies

March 23, 2006
Author(s)
Adriaan C. Carter, Raju V. Datla, Timothy M. Jung, Allan W. Smith, James A. Fedchak
The Low Background Infrared (LBIR) facility at the National Institute of Standards and Technology (NIST) has performed 10 calibrations of low-background blackbodies since 2001 when the calibration facility and calibration method for low-background

Measurement of Small Apertures

March 23, 2006
Author(s)
James A. Fedchak, Adriaan C. Carter, Raju V. Datla
The Low Background Infrared calibration (LBIR) facility at the National Institute of Standards and Technology (NIST) is developing a relative aperture area instrument to measure the areas of apertures with diameters ranging from 5 mm to 0.05 mm. NIST

Status of High-Voltage, High-Frequency Silicon-Carbide Power Devices

March 22, 2006
Author(s)
Allen R. Hefner Jr.
The emergence of High-Voltage, High-Frequency (HV-HF) Silicon-Carbide (SiC) power devices is expected to revolutionize commercial and military power distribution and conversion systems. The DARPA Wide Bandgap Semiconductor Technology (WBST) High Power
Displaying 35001 - 35025 of 74229
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