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Displaying 1526 - 1550 of 2606

Perturbations from Ducts on the Modes of Acoustic Thermometers

September 1, 2009
Author(s)
Keith A. Gillis, Michael R. Moldover, Hong Lin
We examine the perturbations of the modes of an acoustic thermometer caused by circular ducts used either for gas flow or as acoustic waveguides coupled to remote transducers. We calculate the acoustic admittance of circular ducts using a model based on

193 nm Angle-Resolved Scatterfield Microscope for Semiconductor Metrology

August 24, 2009
Author(s)
Martin Y. Sohn, Richard Quintanilha, Bryan M. Barnes, Richard M. Silver
An angle-resolved scatterfield microscope (ARSM( feating 193 nm excimer laser light wa developed for measuring critical dimension (CD) and overlay of nanoscale targets as used in semiconductor metrology. The microscope is designed to have a wide and

A moving window correlation method to reduce the distortion of SPM images

August 20, 2009
Author(s)
Wei Chu, Joseph Fu, Ronald G. Dixson, Ndubuisi G. Orji, Theodore V. Vorburger
Many scanning probe microscopes (SPMs), such as the scanning tunneling microscope (STM) and atomic force microscope (AFM), use piezoelectric actuators operating in open loop for generating the scans of the surfaces. However, nonlinearities mainly caused by

Glassy Carbon as an Absolute Intensity Calibration Standard for Small Angle Scattering

August 19, 2009
Author(s)
Andrew J. Allen, Jan Ilavsky, Fan Zhang, Gabrielle G. Long, Pete R. Jemian
Absolute calibration of small-angle scattering (SAS) intensity data (in units of differential cross-section per unit sample volume per unit solid angle) is essential for many important aspects of quantitative SAS analysis, such as obtaining the number

System Builders Manual for Version 2.1.5 of the NIST DMIS Test Suite

August 19, 2009
Author(s)
Thomas R. Kramer, John A. Horst
This is a system builders manual for the NIST DMIS Test Suite, version 2.1.5. The purpose of the manual is to help system builders use software provided in the test suite for building systems that implement DMIS (the Dimensional Measuring Interface

Users Manual for Version 2.1.5 of the NIST DMIS Test Suite (for DMIS 5.1)

August 19, 2009
Author(s)
Thomas R. Kramer, John A. Horst
The NIST DMIS Test Suite, version 2.1.5, is described. The test suite is intended to serve two purposes, 1) to help users and vendors use version 5.1 of DMIS (the Dimensional Measuring Interface Standard) and 2) to provide utilities and test files for

Nanoscale Photoresponse in Blended Organic Photovoltaics

August 16, 2009
Author(s)
Behrang H. Hamadani, Suyong S. Jung, Nikolai B. Zhitenev
Organic solar cells, which have attracted considerable interest over the last few years as low-cost, simply-processed alternatives for harvesting the solar energy, have interesting nanoscale properties; a thorough understanding of which is currently

Coalescing GSICS Correction Coefficients

August 14, 2009
Author(s)
Ruediger Kessel
We would like to present a technique to adjust the uncertainty estimates of each point in a time series, so that the variance of the time series is consistent with the uncertainty estimates of its component points. This would allow the uncertainty of the

Dynamic Gravitational Standard for Liquid Flow: Model and Measurements

August 14, 2009
Author(s)
Iosif I. Shinder, Michael R. Moldover
We report progress in testing a dynamic gravimetric standard using both steady and unsteady water flows. For steady flows in the range 10 kg/s to 60 kg/s, the difference between the dynamic standard and NIST s static primary standard was 0.015 % with a

The Calculation of Natural Gas Viscosity

August 14, 2009
Author(s)
Aaron N. Johnson, William Johansen
The calculation of natural gas viscosity has been implemented many different ways including the use of constants. Different methods of calculating natural gas viscosity may produce values with differences as large as 50%. Increasing natural gas prices

Reference measurements of Hydrogen's Dielectric Permittivity

August 10, 2009
Author(s)
James W. Schmidt, Michael R. Moldover, Eric F. May
We used a quasi-spherical cavity resonator to measure the relative dielectric permittivity ε r of H 2 at frequencies from 2.4 GHz to 7.3 GHz, at pressures up to 6.5 MPa, and at the temperatures 273 K and 293 K. The resonator was calibrated using auxiliary

High Definition Flow

August 1, 2009
Author(s)
John D. Wright, Michael R. Moldover
From pharmaceutical production to the natural gas market, exact flow measurements are critical. Here's how NIST helps keep us all on the same page.

Recent developments in large-scale dimensional metrology

July 30, 2009
Author(s)
G Peggs, P.G Maropoulos, E.B Hughes, Alistair Forbes, S Robson, M Ziebart, Bala Muralikrishnan
With ever-more demanding requirements for the accurate manufacture of large components, dimensional measuring techniques are becoming progressively more sophisticated. This review describes some of the more recently-developed techniques and the state-of

Measurement and Standards: The role of NIST

July 29, 2009
Author(s)
Kent B. Rochford
At NIST, said Dr. Rochford, "we are very broad, but we focus like a laser on measurement science." NIST also helps develop standards and promote technology. He called the institute "fairly small," with about 2,800 employees and almost that many affiliated

Degradation and Nanofiller Release of Polymer Nanocomposites Exposed to UV

July 15, 2009
Author(s)
Tinh Nguyen, Bastien T. Pellegrin, Alexander J. Shapiro, Xiaohong Gu, Joannie W. Chin
Nanofillers are increasingly used to enhance multifunctional properties of polymers. However, recent research suggests that nanomaterials may have a negative impact on the environmental health and safety. Since polymers are susceptible to photodegradation

Nanoscale Measurements with a Through-Focus Scanning-Optical-Microscope

July 15, 2009
Author(s)
Ravikiran Attota, Richard M. Silver, Thomas A. Germer
We present a novel optical technique that produces nanometer dimensional measurement sensitivity using a conventional optical microscope, by analyzing through-focus scanning-optical-microscope (TSOM) images obtained at different focus positions. In

Long-Term Performance of Nano-Filled Polymeric Materials: Effect of ZnO Nanoparticles on Photodegradation of a Waterborne Polyurethane Coating

July 8, 2009
Author(s)
Xiaohong Gu, Dongmei Zhe, Minhua Zhao, Guodong Chen, Nhieu Ly, Paul E. Stutzman, Li Piin Sung, Tinh Nguyen, Joannie W. Chin
Polymers are widely used as exterior coatings in buildings, bridges, aircrafts and automobiles for both protection and aesthetic purposes. However, the service life of the applied coatings is limited due to the photodegradation of polymers induced by

Certification Report for SRM 2112 and 2113

July 1, 2009
Author(s)
Christopher N. McCowan
This report documents the procedures used to develop certified maximum force and absorbed energy values for SRM 2112 and SRM 2113. The report serves to provide outside observers with accurate and detailed information on how the materials were certified and

Economics of Measurement Uncertainty and Tolerances

July 1, 2009
Author(s)
Steven D. Phillips, J.M. Baldwin, William T. Estler
Productivity is considered by considering Cobb-Douglas production function and focusing on total factor productivity (TFP). We argue that developed economies like the United States need to develop TFP by utilizing advances in computation power and insights

Sensitivities and Variances for Fitted Parameters of Spheres

July 1, 2009
Author(s)
Christoph J. Witzgall, Marek Franaszek
Experimental data have been gathered by applying 3D imaging systems, such as LIDAR/LADAR instruments, to spherical objects. This report provides a compilation of the statistical and analytical procedures to be used for an evaluation, to be reported
Displaying 1526 - 1550 of 2606