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Displaying 30801 - 30825 of 73779

Nanoimprint Lithography and the Role of Viscoelasticity in the Generation of Residual Stress in Model Polystyrene Patterns

June 10, 2008
Author(s)
Yifu Ding, Hyun Wook Ro, Jing N. Zhou, Brian C. Okerberg, Jack F. Douglas, Alamgir Karim, Christopher L. Soles
Understanding polymer deformation during the nanoimprinting process is key to achieve robust polymer nanostructures. Information regarding the process can be extracted from monitoring the decay of the imprinted polymer patterns during thermal annealing. In

Scanning Probe Microscopy for Dielectric and Metal Characterization

June 10, 2008
Author(s)
Joseph J. Kopanski, Thomas R. Walker
The properties of both insulators and metals can be characterized capacitively with scanning probe microscopy, though the techniques employed are different. Intermittent contact scanning capacitance microscopy (IC-SCM) is a useful technique for

Subspace Linear Discriminant Analysis for Face Recognition

June 10, 2008
Author(s)
W Zhao, R Chellappa, P. Jonathon Phillips
In this correspondence, we describe a holistic face recognition method based on subspace Linear Discriminant Analysis (LDA). Like existing methods, this method consists of two steps: first, the face image is projected into a face subspace via Principal

Understanding EuP and REACH

June 10, 2008
Author(s)
John V. Messina, Eric D. Simmon
There has been a world-wide trend towards legislation meant to encourage sustainable manufacturing and minimize the environmental impact of product manufacturing. In the global economy, with its distributed supply chain, local environmental laws may affect

Violation of Cauchy-Schwarz Inequality in the Macroscopic Regime

June 10, 2008
Author(s)
Alberto M. Marino, V Boyer, Paul D. Lett
We have observed a violation of the Cauchy-Schwarz inequality in the macroscopic regime by more than 8 standard deviations. The violation has been obtained while filtering out only the low frequency noise of the quantum-correlated beams that results from

Calculated Performance of Low-Porosity Regenerators at 4 K with He-4 and He-3

June 9, 2008
Author(s)
Ray Radebaugh, Yonghua Huang, Agnes A. O'Gallagher, John M. Gary
Previously we have shown that the lower volumetric heat capacity and more ideal behavior of helium-3 compared with helium-4 at 4 K results in an improved performance for packed sphere regenerators operating with helium-3 between 4 K and about 20 K. In this

Extraction of trench geometry and linewidth of nanoscale grating targets in (110)-oriented silicon using angle-resolved scatterometry

June 9, 2008
Author(s)
Heather J. Patrick, Thomas A. Germer, Michael W. Cresswell, Bin Li, Huai Huang, Paul S. Ho
The extraction of nanoscale dimensions and feature geometry of grating targets using signature-based optical techniques is an area of continued interest in semiconductor manufacturing. In the current work, we have performed angle-resolved scatterometry

Improvements in the NIST Johnson Noise Thermometry System

June 9, 2008
Author(s)
Samuel Benz, Horst Rogalla, Rod White, Jifeng Qu, Paul Dresselhaus, Wes L. Tew, Sae Woo Nam
We have developed a Johnson noise thermometry system that is calibrated by precision waveforms synthesized with a quantum-accurate voltage noise source (QVNS). Significant improvements to the QVNS and the cross-correlation measurement electronics have

Precision Differential Sampling Measurements of Low-Frequency Voltages Synthesized with an AC Programmable Josephson Voltage Standard

June 9, 2008
Author(s)
Alain Rufenacht, Charles J. Burroughs, Samuel P. Benz, Paul D. Dresselhaus, Bryan C. Waltrip, Thomas L. Nelson
Sampling is a promising technique to compare the stepwise-approximated sine waves synthesized by an AC Programmable Josephson Voltage Standard to the sinusoidal voltages of a secondary source at low frequencies (a few hundred Hz or less). This paper

Progress toward a 1V Pulse-Driven AC Josephson Voltage Standard

June 9, 2008
Author(s)
Samuel Benz, Paul Dresselhaus, Norman F. Bergren, Regis Landim
We present a new record output voltage of 275 mVrms, which is a 25% improvement over the maximum achieved with previous ac Josephson voltage standard circuits. We demonstrate operating margins for these circuits and use them to measure the harmonic

Pulse Tube Cryocooler for Rapid Cooldown of A Superconducting Magnet

June 9, 2008
Author(s)
Michael A. Lewis, Ryan P. Taylor, Peter E. Bradley, Isaac Garaway, Ray Radebaugh
A single-stage pulse tube cryocooler was designed to provide rapid cooldown of a high temperature superconducting (HTS) magnet that is part of a gyrotron required for the generation of a high-power mm-wave (95 GHz) beams. These beams are used in the

Towards a Low-Jitter 10 GHz Pulsed Source with an Optical Frequency Comb Generator

June 9, 2008
Author(s)
Shijun Xiao, Leo W. Hollberg, Nathan R. Newbury, Scott A. Diddams
We demonstrate low residual timing jitter of 10 GHz pulses from a 1.55 m optical frequency comb generator based on a doubly-resonant electro-optic modulator. The comb spectral phase is shown to be linear for each sideband but of different slopes. The

ANTENNA TEST RANGE IMAGING USING SPHERICAL NEAR-FIELD SCANNING

June 8, 2008
Author(s)
Michael H. Francis, Ronald C. Wittmann, Randy Direen
Although the theory is straightforward, practical implementation of spherical near-field scanning for evaluating test chambers presents some significant challenges. Among these are the selection of an appropriate probe and the difficulty in minimizing

Bilateral optical fiber power meter linearity comparison between NMIJ and NIST

June 8, 2008
Author(s)
Seiji Mukai, Kuniaki Amemiya, Michiyuki Endo, Igor Vayshenker, Xiaoyu X. Li, Shao Yang
Optical fiber power meter (OFPM) linearity standards of NMIJ (Japan) and NIST (USA) are compared using a commercial OFPM as a transfer standard at 1310 nm and 1550 nm over a power range [-60 dBm, 0 dBm]. At both wavelengths the comparison indicates an

Calibrated Broadband Electrical Characterization of Nanowires

June 8, 2008
Author(s)
Thomas Mitchell (Mitch) Wallis, Atif A. Imtiaz, Hans Nembach, Kristine A. Bertness, Norman Sanford, Paul T. Blanchard, Pavel Kabos
A technique is presented for the broadband electrical characterization of nanowires. The technique relies on established on-wafer calibration methods as well as a direct measurement of the capacitive coupling that is in parallel with the nanowire

Complete waveform characterization at NIST

June 8, 2008
Author(s)
Paul D. Hale, Tracy S. Clement, Darryl A. Keenan, Dylan F. Williams, Arkadiusz C. Lewandowski, C. M. Wang, Andrew Dienstfrey
We present a method for calibrating the voltage a pulse generator delivers to a load at every point in the measured waveform epoch. The calibration includes an equivalent circuit model of the generator so that the user can calculate how the generator will

High Rate Tensile Strength Measurements of Frangible Bullets Using a Kolsky Bar

June 8, 2008
Author(s)
Steven P. Mates, Richard L. Rhorer, Stephen W. Banovic, Eric P. Whitenton, Richard J. Fields
The tensile strength of frangible bullets is measured by a high rate diametral compression test (DCT) performed with a Kolsky Bar. Frangible bullets, meant to disintegrate on impact by brittle failure, also exhibit significant plasticity in compression. As

High resolution spectroscopy using fiber-laser frequency combs

June 8, 2008
Author(s)
Ian R. Coddington, William C. Swann, Nathan R. Newbury
The output of a femtosecond fiber laser can be both spectrally broadened and stabilized, thereby providing a broadband coherent source in the near infrared. In the frequency domain, the result is a frequency comb with frequency stabilities at the

Noise-parameter measurement with automated variable terminations

June 8, 2008
Author(s)
Dazhen Gu, Dave K. Walker, James P. Randa
NIST has upgraded its measurement capability of noise parameters on low-noise amplifiers with a variable termination unit in the 1 to 12.4 GHz range. Such a unit allows improved time efficiency in the noise-temperature measurements used to de-embed noise

Permittivity and Permeability and the Basis of Effective Parameters

June 8, 2008
Author(s)
James R. Baker-Jarvis, Michael D. Janezic, Billy F. Riddle
The concepts of effective permittivity and permeability are used throughout the literature to describe both highly heterogeneous materials, inhomogeneous materials, and small collections of molecules. In this paper we study definitions of the permittivity

Uncertainty Analysis for Noise-Parameter Measurements

June 8, 2008
Author(s)
James P. Randa
A brief summary is presented for the uncertainty analysis for measurements of noise parameters of amplifiers and transistors, in both connectorized (coaxial) and on-wafer environments. We treat both the X-parameters, which are based on the wave
Displaying 30801 - 30825 of 73779
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