U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 1901 - 1925 of 2934

Nested Uncertainties and Hybrid Metrology to Improve Measurement Accuracy

April 18, 2011
Author(s)
Richard M. Silver, Nien F. Zhang, Bryan M. Barnes, Hui Zhou, Jing Qin, Ronald G. Dixson
In this paper we present a method to combine measurement techniques that reduce uncertainties and improve measurement throughput. The approach has immediate utility when performing model-based optical critical dimension measurements. When modeling optical

Workshop on Bridging Satellite Climate Data Gaps

February 16, 2011
Author(s)
Catherine C. Cooksey, Raju V. Datla
Detecting the small signals of climate change for the most essential climate variables requires that satellite sensors make highly accurate and consistent measurements. Data gaps in the time series (such as possible launch delay or failure) or

WATER TRANSPORT ACROSS A POLYMER ELECTROLYTE MEMBRANE UNDER THERMAL GRADIENTS

January 11, 2011
Author(s)
David L. Jacobson, Richard Fu, Takeshi Shiomi, Ugur Pasaogullari, Joshua Preston, Shinichi Miyazaki, Yuichiro Tabuchi, Daniel S. Hussey
A fundamental experimental and numerical study of the water transport across a perfluorosulfonic acid (PFSA) membrane under a temperature gradient is presented. The water transport phenomenon was experimentally investigated through water flux measurement

Framework Type Determination for Zeolite Crystals in the Inorganic Crystal Structure Database

September 1, 2010
Author(s)
Shujiang Yang, Mohammed Lach-hab, Iosif I. Vaisman, Estela Blaisten-Barojas, Xiang Li, Vicky L. Karen
This work provides assignment of framework type for 1391 zeolite crystal entries in the Inorganic Crystal Structure Database (ICSD). Additionally, a proposed framework type is provided for a set of 27 zeolite crystals with geometrical distortions and a set

Phase Noise in the Photodetection of Ultrashort Optcial Pulses

June 2, 2010
Author(s)
Jennifer A. Taylor, Franklyn J. Quinlan, Archita Hati, Craig W. Nelson, Scott A. Diddams, Shubahshish Datta, Abhay Joshi
Femtosecond laser frequency combs provide an effective and efficient way to take an ultra-stable optical frequency reference and divide the signal down into the microwave region. In order to convert optical pulses into a usable rf signal, one must use high

Nanomechanical Measurements and Tools

February 23, 2010
Author(s)
Robert F. Cook
Nanotechnology provides great opportunities for the development of advanced devices with enormous quality-of-life and economic benefits, with applications ranging from biomedical implantable actuators to environmental toxin detectors to infrastructural

Vibration spectrum of a low-vibration pulse-tube cryostat from 1 Hz to 20 kHz

January 11, 2010
Author(s)
Akobuije D. Chijioke, John R. Lawall
The vibrations of the cold finger of a low-vibration helium pulse-tube cryostat are measured from 1 Hz to 20 kHz using an optical interferometer specially designed to measure small vibrations at high frequencies in the presence of large vibrations at lower

Ultrafast Demagnetization Dynamics at the M Edges of Magnetic Elements Observed Using a Tabletop High-Harmonic Soft X-Ray Source

December 15, 2009
Author(s)
Thomas J. Silva, Justin Shaw, Hans Nembach, Chan La-O-Vorakiat, Mark Siemens, Margaret M. Murnane, Henry C. Kapteyn, Stefan Mathias, Martin Aeschlimann, Patrik Grychtol, Roman Adam, Claus M. Schneider
We use few-femtosecond soft x-ray pulses from high-harmonic generation to extract element-specific demagnetization dynamics and hysteresis loops of a compound material for the first time. Using a geometry where high-harmonic beams are reflected from a

Traceable waveform calibration with a covariance-based uncertainty analysis

October 1, 2009
Author(s)
Paul D. Hale, Dylan F. Williams, Andrew M. Dienstfrey, Arkadiusz C. Lewandowski, Tracy S. Clement, Darryl A. Keenan
We describe a method for calibrating the voltage that a step-like pulse generator produces at a load at every time point in themeasured waveform. The calibration includes an equivalent-circuit model of the generator that can be used to determine how the

REFERENCE MATERIALS FOR RHEOMETERS AND THE FLOW TABLE

August 3, 2009
Author(s)
Chiara F. Ferraris, Zughuo Li, Mona Mohseni, Nicholas Franson
Oil is the most used standard material for the calibration of rheometers. Other products are used to calibrate flow devices, i.e., the flow table is calibrated using a mixture of oil and silica powder. The oil is a Newtonian liquid while the oil-silica

Building Quantum Computers

December 1, 2008
Author(s)
Emanuel H. Knill
In theory, quantum computers can be used to efficiently factor numbers, quadratically speed up many search and optimization problems, and enable currently impossible physics simulations. At first, quantum states appeared to be too fragile for implementing

Capacity of Random Wireless Networks: Impact of Cooperative Network Coding

May 19, 2008
Author(s)
Yi Qian, Kejie Lu, Shengli Fu
The throughput capacity of random wireless networks has been studied extensively in the literature. Nevertheless, most existing studies are based on the assumption that each transmission has one sender and one receiver. In our recent study, we have

Passive Cooling of a Micromechanical Oscillator with a Resonant Electric Circuit

September 28, 2007
Author(s)
Kenton R. Brown, Joseph W. Britton, Ryan Epstein, John Chiaverini, Dietrich G. Leibfried, David J. Wineland
Currently there is considerable interest in the cooling of macroscopic mechanical oscillators, as strong cooling may allow one to reach the quantum regime of such oscillators. Recent advances in microfabrication and cooling techniques have brought this

Effect of Lubricant on R410A Horizontal Flow Boiling

September 27, 2007
Author(s)
N N. Sawant, Mark A. Kedzierski, J S. Brown
The paper experimentally quantified the effect of lubricant on horizontal flow boiling of R410A. This was accomplished by first establishing a baseline by measuring the convective boiling heat transfer performance of pure R410A. The heat transfer

A proposed laser frequency comb based wavelength reference for high resolution spectroscopy

September 12, 2007
Author(s)
Steve Osterman, Scott A. Diddams, Matthew Beasley, Cynthia Froning, Leo W. Hollberg, Phillip MacQueen, Vela Mbele, Andrew Weiner
High resolution spectroscopy is the foundation for many of the most challenging and productive of all astronomical observations. A highly precise, repeatable and stable wavelength calibration is especially essential for long term RV observations. The two

Science based Information Metrology for Engineering Informatics

September 1, 2007
Author(s)
Sudarsan Rachuri
Engineering informatics is the discipline of creating, codifying (structure and behavior that is syntax and semantics), exchanging (interactions and sharing), processing (decision making), storing and retrieving (archive and access) the digital objects

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

Laser Cooling Without Repumping: A Magneto-Optical Trap for Erbium Atoms

April 14, 2006
Author(s)
Jabez J. McClelland, James L. Hanssen
We report on a novel mechanism that allows for laser cooling of atoms that do not have a closed cycling transition. This mechanism is observed in a magneto-optical trap for erbium, an atom with a very complex energy level structure with multiple pathways

Advanced Metrology Needs for Nanotechnology and Nanomanufacturing

November 1, 2005
Author(s)
Michael T. Postek, John S. Villarrubia, Andras Vladar
Advances in fundamental nanoscience, design of nanomaterials, and ultimately manufacturing of nanometer scale products all depend to some degree on the capability to accurately and reproducibly measure dimensions, properties, and performance
Displaying 1901 - 1925 of 2934
Was this page helpful?