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 4651 - 4675 of 74178

Cautionary Note on Contamination of Reagents Used for Molecular Detection of SARS-CoV-2

May 3, 2021
Author(s)
Peter Vallone, James Huggett, Vladimir Benes, Jeremy Garson, Kathryn Harris, Mikael Kubista, Timothy McHugh, Jacob Moran-Gilad, Tania Nolan, Michael Pfaffl, Marc Salit, Greg Shipley, Jo Vandesompele
Reverse transcription (RT)-PCR, the principal diagnostic method applied in the world-wide struggle against COVID-19, is capable of detecting a single molecule of a viral genome. Correctly designed and practiced RT-PCR assays for SARS-CoV-2 should not cross

Comparison of electrostatic and photon pressure force references at the nanonewton level

May 3, 2021
Author(s)
Gordon Shaw, John A. Kramar, Paul Williams, Matthew Spidell, Richard Mirin, Julian Stirling
This work describes a comparison between nanonewton force references derived from an electrostatic force balance and photon pressure force from calibrated laser optical power in the 1 watt range. The NIST Electrostatic Force Balance (EFB) is used to

Filling the Pharmacopeial Gaps of Visual Inspection Toward Standardization and Consistency of Visible Particle Testing

May 3, 2021
Author(s)
Linda Narhi, George M. Bou-Assaf, Kristen Gonzalez, Maryam Mazaheri, Steven Messick, Srivalli Telikepalli
The presence of visible particles that are not anticipated to be present in drug products is one of the most common causes of recalls, and warning letters1, 2. This critical quality attribute, which is typically determined during visual inspection (along

Quantum field theory for the chiral clock transition in one spatial dimension

May 3, 2021
Author(s)
Seth P. Whitsitt, Rhine Samajdar, Subir Sachdev
We describe the quantum phase transition in the N-state chiral clock model in spatial dimension d=1. With couplings chosen to preserve time-reversal and spatial inversion symmetries, such a model, is in the universality class of recent experimental studies

Report of the 104th National Conference on Weights and Measures

May 3, 2021
Author(s)
Yvonne Branden
The 104th Annual Meeting of the National Conference on Weights and Measures (NCWM) was held July 14 - 18, 2019, at the Hyatt Regency Milwaukee Hotel, Milwaukee, Wisconsin. The theme of the meeting was "Assuring Equity in the Marketplace: NIST and NCWM

Revision of the SNPforID 34-plex forensic ancestry test: Assay enhancements, standard reference sample genotypes and extended population studies

May 3, 2021
Author(s)
John Butler, Manuel Fondevila, Carla Santos, Ana Freire, Christopher Phillips, M Lareu, Peter Vallone
A revision of an established 34 SNP forensic ancestry test has been made by swapping the under- performing rs727811 component SNP with the highly informative rs3827760 that shows a near-fixed East Asian specific allele. We collated SNP variability data for

Scaling of Mass and Force Using Electrical Metrology

May 3, 2021
Author(s)
Gordon Shaw
The impending redefinition of the International System of Units (SI) allows realization of the kilogram using electrical metrology. It can be shown that electrical metrology can also be used to scale mass using electrostatic forces. An approach to mass

Beyond Color: The New Carbon Ink

May 2, 2021
Author(s)
Ming Zheng, YuHuang Wang
For thousands of years, carbon ink has been used as a black color pigment for writing and painting purposes. However, recent discoveries of nanocarbon materials, including fullerenes, carbon nanotubes, graphene, and their various derivative forms, together

Orientational ordering within semiconducting polymer fibrils

May 2, 2021
Author(s)
Subhrangsu Mukherjee, Eliot Gann, Masrur M. Nahid, Terry McAfee, Andrew Herzing, Dean DeLongchamp, Harald W. Ade
Due to a general paucity of suitable characterization methods, the internal orientational ordering of polymer fibrils has rarely been measured despite its importance particularly for semi-conducting polymers. An emerging tool with sensitivity to bond

Distributed fiber optic measurements of strain and temperature in long-span composite floor beams with simple shear connections subject to compartment fires

May 1, 2021
Author(s)
Yanping Zhu, Matthew Klegseth, Yi Bao, Matthew Hoehler, Lisa Choe, Genda Chen
This study explores an instrumentation strategy using distributed fiber optic sensors to measure strain and temperature through the concrete volume in large-scale structures. Single-mode optical fibers were deployed in three 12.8 m long steel and concrete

Residential net-zero energy buildings: Review and perspective

May 1, 2021
Author(s)
Wei Wu, Harrison Skye
Advancements in residential net-zero energy buildings (NZEBs) could significantly reduce energy use and greenhouse gas emissions. NZEB design considerations broadly categorize into energy infrastructure connections, renewable energy sources, and energy

Entanglement and purification transitions in non-Hermitian quantum mechanics

April 30, 2021
Author(s)
Michael Gullans, Sarang Gopalakrishnan
A quantum system subject to continuous measurement and post-selection evolves according to a non- Hermitian Hamiltonian. We show that, as one increases the rate of post-selection, this non- Hermitian Hamiltonian can undergo a spectral phase transition. On
Displaying 4651 - 4675 of 74178