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 23276 - 23300 of 74203

A Direct Comparison System for Power Calibration up to 67 GHz*

July 1, 2012
Author(s)
Thomas M. Wallis, Thomas P. Crowley, Denis X. LeGolvan, Ronald A. Ginley
A direct comparison system for calibration of power sensors with 1.85 mm precision coaxial connectors up to 67 GHz has been developed. The comparison is implemented in two frequency bands. Between 10 MHz and 50 GHz, power sensors with 2.4 mm coaxial

Calibration Techniques for Scanning Microwave Microscopy

July 1, 2012
Author(s)
Thomas M. Wallis, Atif A. Imtiaz, Alexandra Curtin, Pavel Kabos, H. P. Huber, Joseph J. Kopanski, F. Kienberger
Two techniques are described for calibrating a scanning microwave microscope (SMM). The first technique enables spatially-resolved absolute capacitance measurements on the attofarad-to-femtofarad scale. The second technique enables profiling or dopant

Electromagnetic Properties of Iron Oxide Corrosion Product Powders at Radio Frequencies

July 1, 2012
Author(s)
Sung Kim, Jack T. Surek, James R. Baker-Jarvis, Virgil Provenzano
We calculated the refractive index from Sparameter data for corrosion samples tested in waveguide from 12.4 GHz to 110 GHz. This approach minimizes the modal noise often seen in derived permittivity and permeability for low-loss samples in this range. Also

Flat frequency response in the electronic measurement of the Boltzmann constant

July 1, 2012
Author(s)
Jifeng Qu, Samuel Benz, Yang Fu, Jianqiang Zhang, Horst Rogalla, Alessio Pollarolo
A new quantum voltage calibrated Johnson noise thermometer (JNT) was developed at NIM to demonstrate the electrical approach that determines the Boltzmann constant k by comparing electrical and thermal noise power. A measurement with integration period of

Improved performance of the ECCS experiment at PTB

July 1, 2012
Author(s)
Hansjoerg Scherer, Benedetta Camarota, Mark W. Keller, Sergey Lotkhov
Recent improvements on the ECCS experiment at PTB are reported. A 5-junction single-electron R-pump is shown to shuttle electrons with a relative transfer error of 5×10 -8. Moreover, the relative uncertainty of the setup for the cryogenic capacitor voltage

Method for Ensuring Accurate AC Waveforms with Programmable Josephson Voltage Standards

July 1, 2012
Author(s)
Charles J. Burroughs, Alain Rufenacht, Samuel P. Benz, Paul D. Dresselhaus
The amplitudes of stepwise-approximated sine waves produced by programmable Josephson voltage standards (PJVSs) are not intrinsically accurate because the transitions between the quantized voltages depend on numerous conditions. We have developed a method

Out-of-plane Stokes imaging polarimeter for early skin cancer diagnosis

July 1, 2012
Author(s)
P. Ghassemi, Paul Lemaillet, Thomas Germer, J. W. Shupp, S. Venna, M. E. Boisvert, K. E. Flanagan, M. H. Jordan, J. C. Ramella-Roman
Optimal treatment of skin cancer before it metastasizes depends critically on early diagnosis and treatment. Imaging spectroscopy and polarized remittance have been utilized in the past for diagnostic purposes, but valuable information can be also obtained

Proton Hopping and Long-Range Transport in the Protic Liquid [Im][TFSI], Probed by Pulsed-Field Gradient NMR and Quasi-Elastic Neutron Scattering

July 1, 2012
Author(s)
Megan L. Hoarfrost, Madhu Sudan Tyagi, Rachel A. Segalman, Jeffrey A. Reimer
Protic ionic liquids are promising candidates for a wide variety of electrochemical applications owing to their high proton conductivity, good thermal and electrochemical stability, and negligible volatility. Proton hopping leads to enhanced conductivity

Simple Test and Modeling of RFID Tag Backscatter

July 1, 2012
Author(s)
Daniel G. Kuester, David R. Novotny, Jeffrey R. Guerrieri, Aniwar Ibrahim, Zoya Popovic
We consider here worst-case analysis of backscatter from passive radio frequency identification (RFID) tags. The basis is a figure of merit "B" to relate link power at reader ports to tag circuit parameters. A minimum bound for received monostatic

Small-Angle Scattering from Branched Polymers

July 1, 2012
Author(s)
Boualem Hammouda
The single-polymer form factor is worked out for branched polynmers using a scaling argument in order to recover the low-Q Porod exponent characterisitc of the overall structure. The high-Q Porod exponent characterizes the local branching structure. An
Displaying 23276 - 23300 of 74203
Was this page helpful?