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Displaying 45376 - 45400 of 74142

Wavelength Calibration Standards for the WDM L-Band

September 1, 2001
Author(s)
William C. Swann, Sarah L. Gilbert
We describe National Institute of Standards and Technology research on wavelength standards for the optical communications L-band. We are developing a pair of transfer standards that can be used to calibrate the wavelength scale and scan linearity of

Workshop on Standards for Biomedical Materials and Devices

September 1, 2001
Author(s)
John A. Tesk, D Hall
The Workshop on Biomedical Materials and Devices, held June 13-14, 2001, is the latest in a series of workshops and topical meetings organized by NIST in the area of biomedical technology. The workshop complements other recent NIST efforts to make its

X-Ray Standing-Wave Investigation of Valence-Electronic Structure

September 1, 2001
Author(s)
Joseph C. Woicik, E J. Nelson, T Kendelewicz, P Pianetta, D Heskett, J Warner, L E. Berman, B A. Karlin, I A. Vartanyants, M Z. Hasan, Z -. Shen
We introduce a new experiment method by which site-specific valence-electronic structure may be obtained. It utilizes the x-ray standing-wave interference field that results from the superposition of the incident and reflected x-ray beams within the

X-Ray Standing-Wave Investigations of Valence Electronic Structure

September 1, 2001
Author(s)
Joseph C. Woicik, E J. Nelson, D Heskett, J Warner, L E. Berman, B A. Karlin, I A. Vartanyants, M Z. Hasan, T Kendelewicz, Z -. Shen, P Pianetta
We have examined the valance-electron emission from Cu, Ge, GaAs, InP, and NiO single crystals under the condition of strong x-ray Bragg reflection; i.e., in the presence of the spatially modulated x-ray standing-wave interference field that is produced by

Improved Time-Base for Waveform Parameter Estimation

August 31, 2001
Author(s)
Bryan C. Waltrip, Owen B. Laug, Gerard N. Stenbakken
An improved gated oscillator time-base and associated auto-calibration algorithm for use in a high-accuracy waveform acquisition system are descrigbed. The time-base architecture consists of a stable 100 MHz gated oscillator, 24-bit counter chain, and a

Implementation of CMOS Compatible Conductance-based Micro-Gas-Sensor System

August 28, 2001
Author(s)
Muhammad Afridi, John S. Suehle, Mona E. Zaghloul, Jason E. Tiffany, Richard E. Cavicchi
A CMOS compatible micro-gas sensor system was designed and fabricated in a standard CMOS process through MOSIS. This chip was post-processed to create microhotplates using bulk micro-machining techniques. Tin-oxide-sensing films were grown over post

High Q resonating cantilevers for in situ measurements of ferromagnetic films

August 24, 2001
Author(s)
John M. Moreland, T. J. Hubbard
We describe micro cantilevers developed for in-situ measurements of ultra-thin ferromagnetic films. The cantilevers are optimized for use in a resonating torque micro-balance magnetometer that measures the magnetic moment of thin films as they are being

Spin-Other-Orbit Interaction and Magnetocrystalline Anisotropy

August 23, 2001
Author(s)
Mark D. Stiles, S Halilov, R Hyman, A Zangwill
We report the effect of the two-body, spin-other-orbit interaction on the magnetocrystalline anisotropy energy of the 3d transition metals. The relevant energy differences were computed for bcc Fe, fcc Ni, and hcp Co using the linearized augmented plane

Haidinger Interferometer for Silicon Wafer TTV Measurement

August 22, 2001
Author(s)
R E. Parks, L Z. Shao, Angela Davies, Christopher J. Evans
We describe a novel configuration for a Haidinger fringe, phase shifting, interferometer to measure the total thickness variation (TTV) of 300mm silicon wafers. The interferometer has only one optical element that is on the order of the size of the wafer

Objective Speech Quality Measures for Internet Telephony

August 20, 2001
Author(s)
T Hall
Measuring voice quality for telephony is not a new problem. However, packet-switched, best-effort networks such as the Internet present significant new challenges for the delivery of real-time voice traffic. Unlike the circuit-switched PSTN, Internet

The Crystal Structure of Chorismate Lyase Shows a New Fold and a Tightly Retained Product

August 15, 2001
Author(s)
David T. Gallagher, M P. Mayhew, Marcia J. Holden, A J. Howard, K J. Kim, V L. Vilker
The enzyme chorismate lyase (CL) catalyzes the removal of pyruvate from chorismate to produce 4-hydroxy benzoate (4HB) for the ubiquinone pathway. In Escherichia coli, CL is monomeric with 164 residues; we have determined the structure of the CL product

Meander Delay Line Challenge Problem: A Comparison Using FDTD, FEM and MOM Techniques

August 13, 2001
Author(s)
Alpesh Bhobe, Christopher L. Holloway, Melinda Piket-May
Full wave finite-difference time-domain (FDTD) and a simplified 1D- finite-difference time-domain technique using the multi-conductor transmission line equations are applied to a delay line to determine its propagation characteristics. The output volatge

Biometric Authentication Technology: From the Movies to Your Desktop

August 7, 2001
Author(s)
Fernando L. Podio, J S. Dunn
Biometrics are automated methods of identifying a person or verifying the identity of a person based on a physiological or behavioral characteristic. Biometric authentication technologies such as face, finger, hand, iris, and speaker recognition are

NIST/BFRL CALIBRATION SYSTEM FOR HEAT-FLUX GAGES

August 6, 2001
Author(s)
William M. Pitts, James R. Lawson, John R. Shields
This report of test describes a heat-flux gage calibration system that was developed at the National Bureau of Standards during the 1970s. It is based on a commercial radiant heater incorporating a tungsten lamp and elliptical mirror. A kaleidoscope flux

Measuring Performance and Intelligence of Intelligent Sytems White Paper 2001

August 4, 2001
Author(s)
Elena R. Messina, Alex Meystel, Larry H. Reeker
Is the measurement of performance for intelligent systems different than that of non-intelligent systems? In this white paper, we explore the various dimensions of evaluation of intelligence and performance. The main areas we tackle are the testing of

A Feature-Based Inspection and Machining System

August 1, 2001
Author(s)
Thomas R. Kramer, Hui-Min Huang, Elena R. Messina, Frederick M. Proctor, Harry A. Scott
This paper describes an architecture for a system for machining and inspectingmechanical piece parts and an implementation of it called the Feature-BasedInspection and Control System (FBICS). In FBICS, the controller of a machiningcenter or coordinate

A Web-based 3D Glossary for Anthropometric Landmarks

August 1, 2001
Author(s)
Sanford P. Ressler
We have created a visual 3D anthropometric landmark glossary usable over the Web. Implemented using VRML, the Virtual Reality Modeling Language, users may easily locate and determine the names of these landmarks. Landmarks are visualized as small spheres

Absolute Extreme Ultraviolet Metrology

August 1, 2001
Author(s)
Charles S. Tarrio, Robert E. Vest, S Grantham
NIST has a long-standing program for the calibration of extreme ultraviolet optical components. Begun with the advent of the Synchrotron Ultraviolet Radiation Facility (SURF) almost 40 years ago, early activities centered on the development and

Active Monitoring and Control of Electron-Beam-Induced Contaminaition

August 1, 2001
Author(s)
Andras Vladar, Michael T. Postek, R Vane
The vacuum system of all scanning electron microscopes (SEMs), even in the so-called clean instruments, have certain hydrocarbon residues that the vacuum pumps do not effectively remove. The cleanliness of the vacuum and the amount and nature of these

Active Monitoring and Control of Electron-Beam-Induced Contamination

August 1, 2001
Author(s)
Andras Vladar, Michael T. Postek, R Vane
The vacuum systems of all scanning electron microscopes (SEMs), even in the so-called clean instruments, have certain hydrocarbon residues that the vacuum pumps do not effectively remove. The cleanliness of the vacuum and the amount and nature of these
Displaying 45376 - 45400 of 74142
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