NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

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 6476 - 6500 of 73697

Measurement Challenges for Spectrum Sensing in Communication Networks

April 27, 2021
Author(s)
Dan Kuester, Yao Ma, Dazhen Gu, Adam Wunderlich, Jason Coder, Joseph R. Mruk
We summarize a few key spectrum sensing measurement challenges and recent advances. Laboratory tests of sensing are complicated by their inseparable and often imbedded role in modern hardware. Results are difficult to calibrate because physical parameters

Optical Scattering Characteristics of 3D Lunar Regolith Particles Measured using X-Ray Nano Computed Tomography

April 27, 2021
Author(s)
Edward Garboczi, Ann Debay, Somen Baidya, Ahmed M. Hassan, Andrew Sharits, Jay D. Goguen, Thomas Lafarge, Mikolas Melius
Shape is a critical property, besides size and material composition, which has a strong effect on the optical scattering characteristics of a particle. In this work, we computationally study how the measured three-dimensional shapes of lunar regolith

Spatially Resolved Photoconductivity in WS2/MoS2 lateral heterostructures

April 27, 2021
Author(s)
Samuel Berweger, Hanyu Zhang, Prasana Sahoo, Benjamin Kupp, Jeffrey Blackburn, Elisa Miller, Thomas Mitchell (Mitch) Wallis, Dmitri Voronine, Pavel Kabos, Sanjini Nanayakkara
The optical and electronic properties of 2D semiconductors are intrinsically linked via the strong interactions between optically excited bound species and free carriers. Here we use near-field scanning microwave microscopy (SMM) to image spatial

A Rod-Packing Hydrogen-Bonded Organic Framework with Suitable Pore Confinement for Benchmark Ethane/Ethylene Separation

April 26, 2021
Author(s)
Xu Zhang, Jia-Xin Wang, Libo Li, Jiyan Pei, Rajamani Krishna, Hui Wu, Wei Zhou, Guodong Qian, Bin Li, Banglin Chen
The discovery of new materials for separating ethane (C 2H 6) from ethylene (C 2H 4) by adsorption is a critical enterprise in the chemical industry. It still remains as a daunting challenge to target both high C 2H 6 adsorption capacity and gas

Iris Recognition on Noah Kalina's Everyday

April 26, 2021
Author(s)
James Matey
In January 2000, Noah Kalina began taking a photograph of himself every day – and has continued for more than 20 years. A time-lapse video of his images can be seen online: EveryDay. These images, and images from similar projects, provide us with

Sequence-based U.S. population data for 7 X STR loci

April 26, 2021
Author(s)
Lisa Borsuk, Carolyn R. Steffen, Kevin M. Kiesler, Peter Vallone, Katherine Gettings
The National Institute of Standards and Technology (NIST) U.S. population sample set of unrelated individuals was used to determine allele and haplotype frequencies for seven X-chromosome short tandem repeat (STR) loci in four linkage groups. DXS7132

Outgassing rate comparison of seven geometrically similar vacuum chambers of different materials and heat treatments

April 23, 2021
Author(s)
James A. Fedchak, Julia Scherschligt, Sefer Avdiaj, Daniel Barker, Stephen Eckel, Ben Bowers, Scott O'Connell, Perry Henderson
We have measured the water and hydrogen outgassing rates of seven vacuum chambers of identical geometry but constructed of different materials and heat treatments. Chambers of five different materials were tested: 304L, 316L, and 316LN stainless steels

Automated Piston Gauge Calibration System.

April 22, 2021
Author(s)
Julia Scherschligt, Yuanchao Yang, Katie M. Schlatter, Robert G. Driver, Christina D. Cross, John S. Quintavalle
Piston gauges or pressure balances are important primary standards for the realization of the SI unit of pressure, the Pascal. The National Institute of Standards and Technology (NIST) operates and maintains a calibration service for these devices, and has

Blackbody Radiation Noise Broadening of Quantum Systems

April 22, 2021
Author(s)
Eric B. Norrgard, Stephen Eckel, Christopher L. Holloway, Eric L. Shirley
Precision measurements of quantum systems often seek to probe or must account for the interaction with blackbody radiation. Over the past several decades, much attention has been given to AC Stark shifts and stimulated state transfer. For a blackbody in

CALIBRATION OF SPECTRORADIOMETERS USING TUNABLE LASERS

April 22, 2021
Author(s)
Yuqin Zong, Ping-Shine Shaw, Joseph Rice, C Cameron Miller
To shorten the long calibration chain when using the conventional source-based approach and therefore to reduce spectroradiometer's calibration uncertainty, we developed a detector-based approach to calibrate spectroradiometers directly against a transfer

Depolarization in diffusely scattering media

April 22, 2021
Author(s)
Thomas A. Germer
We performed Mueller matrix Monte Carlo simulations of the propagation of optical radiation in diffusely scattering media for collimated incidence and report depolarization in the the transmitted rays as a function of thickness, the angle subtended by the

Discovering Critical KPI Factors from Natural Language in Maintenance Work Orders

April 22, 2021
Author(s)
Michael Sharp, Michael Brundage, Rachael Sexton, Fnu Madhusudanan Navinchandran
Optimizing maintenance practices is a continuous process that must take into account the evolving state of the equipment, resources, workers, and more. To help streamline this process, facilities need a concise procedure for identifying critical tasks and

Quantum Blackbody Thermometry

April 22, 2021
Author(s)
Eric B. Norrgard, Stephen Eckel, Christopher L. Holloway, Eric L. Shirley
Blackbody radiation (BBR) sources are calculable radiation sources that are frequently used in radiometry, temperature dissemination, and remote sensing. Despite their ubiquity, blackbody sources, have a plethora of systematics (e.g., emissivity

Recent research and development in photometry at NIST

April 22, 2021
Author(s)
Yuqin Zong, Maria Nadal, Benjamin K. Tsai, C Cameron Miller
Many developments were made in recent years in photometry at NIST for reducing measurement uncertainties, increasing calibration efficiencies, and adding measurement capabilities. The 40 years old photometry laboratory has been renovated. The new

Spatial frequency domain Mueller matrix imaging

April 22, 2021
Author(s)
Joseph Chue-Sang, Aaron Goldfain, Jeeseong C. Hwang, Thomas A. Germer
We combine Mueller matrix polarimetry (MMP) with spatial frequency domain imaging (SFDI) to create a technique that is sensitive to near-surface material anisotropy. We demonstrate this imaging modality with scattering and absorbing phantoms and with a

STANDARD LEDS WITH SUPERIOR LONG-TERM STABILITY

April 22, 2021
Author(s)
Yuqin Zong, Weiqiang Zhao, C Cameron Miller
A large-chip standard LED with superior long-term stability have been developed at NIST. The standard LED uses a large, specialty die rated for 50 W but is operated under 3 W to eliminate aging effect. The standard LED was seasoned for one year and
Displaying 6476 - 6500 of 73697
Was this page helpful?