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 76 - 100 of 2583

Development of an Improved Standard Reference Material for Folate Vitamers in Human Serum

December 12, 2022
Author(s)
Johanna Camara, Jeanita Pritchett, Yasmine Daniels, Mary Bedner, Michael Nelson, Mark Lowenthal, Zia Fazili, Christine Pfeiffer, Karen W. Phinney, Katherine E. Sharpless, Lane C. Sander, Katrice Lippa, James H. Yen, Adam Kuszak, Stephen Wise
The US National Institute of Standards and Technology (NIST) developed a Standard Reference Material® (SRM®) 3949 Folate Vitamers in Frozen Human Serum to replace SRM 1955 Homocysteine and Folate in Human Serum. The presence of increased endogenous levels

Gas Flow Standards and Their Uncertainty

December 12, 2022
Author(s)
John D. Wright, Aaron Johnson, Michael R. Moldover, Shin-ichi Nakao
We review diverse types of gas flow standards that are used to calibrate other gas flow meters. For each type of standard, we describe the principles of its operation and at least one hardware example. We identify the practical limits of the example's

Cannabis Laboratory Quality Assurance Program: Exercise 2 Moisture Final Report

November 29, 2022
Author(s)
Chuck Barber, Colleen E. Bryan Sallee, Carolyn Burdette, Shaun Kotoski, Melissa M. Phillips, Walter Brent Wilson, Laura Wood
In 2020, NIST launched Cannabis Laboratory Quality Assurance Program (CannaQAP) to improve the comparability of the analytical measurements of cannabis and cannabis-derived products in forensic and cannabis (hemp and marijuana) testing laboratories

Calculation of magnetic forces and torques on the Kibble coil

October 22, 2022
Author(s)
Stephan Schlamminger, Lorenz Keck, Frank Seifert, Leon Chao, Darine El Haddad, Shisong Li
Analytically the force and torques on a coil in a field of magnetic flux density can be calculated one of two ways. The line integral can be conducted along the coil's wire, summing up the differential force contribution. For each differential line segment

2022 NCWM-NIST National Survey on 20 lb LPG (Propane) Cylinders

October 19, 2022
Author(s)
David Sefcik, Katrice Lippa, N. Alan Heckert, Stephen Benjamin, Ivan Hankins, Don Onwiler
The National Conference on Weights and Measures (NCWM) in partnership and cooperation with the NIST Office of Weights and Measures (OWM) and the Weights and Measures Divisions of select U.S. States initiated the 2022 National Survey on 20 lb LPG (Propane)

The Digital NIST: Challenges and opportunities in the digital transformation of NIST's calibration services

September 21, 2022
Author(s)
Catherine Cooksey, James A. Fedchak, Robert Hanisch, Gregory (Greg) C. Cala, Damian Lauria, Raymond Plante, Benjamin Long, John S. Quintavalle, Manmohan Moodra
Early in 2022 NIST embarked on a pilot project to produce digital calibration reports and certificates of analysis for reference materials. The goal of the project was to produce a few examples of each for the purpose of assessing the scope and challenges

The Digital NIST: Challenges And Opportunities in the Digital Transformation of NIST's Reference Materials

September 21, 2022
Author(s)
William Dinis Camara, Steven J. Choquette, Katya Delak, Robert Hanisch, Benjamin Long, Melissa M. Phillips, Jared Ragland, Kate Rimmer
Early in 2022 NIST embarked on a pilot project to produce digital calibration reports and digital certificates of analysis for reference materials. The goal of the project is to produce a few examples of digital reports and certificates for the purpose of

Energy Broadening of Neutron Depth Profiles by Thin Polyamide Films

September 7, 2022
Author(s)
Jamie Weaver, Anna Job, Kedar Manandhar, Ichiro Takeuchi, Robert Gregory Downing
A protective covering is often required for neutron depth profiling (NDP) measurements of sensitive materials (e.g., Li-ion batteries). Addition of this layer can increase NDP profile energy broadening and depth assignment uncertainty. This study evaluates

Improved Uranium Particle Analysis by SIMS using O3- Primary Ions

September 6, 2022
Author(s)
Evan Groopman, Todd Williamson, David S. Simons
We have investigated the use of negative molecular oxygen primary ion beams (i.e., O2- and O3-) to determine the benefits of using such beams for uranium particle SIMS analyses. Typically, O- is the most practical negative primary ion species for both age

Overcoming Technological Barriers in Microfluidics: Leakage Testing

September 1, 2022
Author(s)
Vania Silverio, Suvajyoti Guha, Armelle Keiser, Rucha Natu, Darwin Reyes-Hernandez, Henne van Heeren, Nicolas Verplanck, Luke Herbertson
The miniaturization of laboratory procedures for Lab-on-Chip (LoC) devices and translation to various platforms such as single cell analysis or Organ-on-Chip (OoC) systems are revolutionizing the life sciences and biomedical fields. As a result

RF Josephson Arbitrary Waveform Synthesizer with Integrated Superconducting Diplexers

August 24, 2022
Author(s)
Akim Babenko, Nathan Flowers-Jacobs, GREGOR LASSER, Justus Brevik, Anna Fox, Paul Dresselhaus, Zoya Popovic, Samuel P. Benz
We present the design, fabrication and characterization of a broadband RF Josephson Arbitrary Waveform Synthesizer (RF-JAWS) with a series array of 4500 Josephson junctions (JJs) and integrated low-pass/high-pass five-pole superconducting diplexers. The

Diffuse Visual Transmission Density

August 17, 2022
Author(s)
Clarence Zarobila, Robert E. Vest, Maria E. Nadal
This document, SP250-99 (2022), NIST Measurement Services: Diffuse Visual Transmission Density, describes the instrument used to measure diffuse visual transmission density of both x-ray and photographic film step tablets. These step tablets replace former

30 GHz regenerative frequency divide-by-3

August 15, 2022
Author(s)
Archita Hati, Marco Pomponio, Connor Humiston, John Lettang, Craig Nelson
We report the performance of a 30 GHz to 10 GHz regenerative frequency divider. The proposed divider design incorporates the conventional Miller regenerative frequency divider (divide-by-2) with an additional regenerative path. We achieve output referred

Prototype of high accuracy single input phase measurement instrument

August 2, 2022
Author(s)
Nicholas G. Paulter Jr., Ioan Tudosa, Francesco Picariello, Pasquale Daponte, Luca De Vito, Sergio Rapuano
A prototype implementation of a phase measurement method (PMM) for a sine-wave signal delivered at the output port of a generator and its experimental assessment is presented. This PMM is capable of measuring the output phase of a sine-wave signal respect

The Expanding Role of National Metrology Institutes in the Quantum Era

July 12, 2022
Author(s)
Alexander Tzalenchuk, Nicolas Spethmann, Tim Prior, Jay H. Hendricks, Yijie Pan, Vladimir Bubanja, Guilherme Temporao, Dai-Hyuk Yu, Damir Ilic, Barbara L. Goldstein
Now that all base units are defined in terms of fundamental constants and can thus — at least in principle — be realized anytime and anywhere, rather than through a measurement chain leading back to unique physical artefacts, who holds the traceability
Displaying 76 - 100 of 2583