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Search Publications

NIST Authors in Bold

Displaying 4376 - 4400 of 74084

Monopolar and dipolar relaxation in spin ice Ho2Ti2O7

June 16, 2021
Author(s)
Yishu Wang, T. Reeder, Y. Karaki, J. Kindervater, T. Halloran, Nicholas C. Maliszewskyj, Yiming Qiu, Jose Rodriguez Rivera, Sergiy Gladchenko, S. M. Koohpayeh, S. Nakatsuji, Collin L. Broholm
Ferromagnetically interacting Ising spins on the pyrochlore lattice of corner-sharing tetrahedra form a highly degenerate manifold of low-energy states. A spin flip relative to this "spin-ice" manifold can fractionalize into two oppositely charged magnetic

Effects of aluminum content on thermoelectric performance of Al CoCrFeNi high-entropy alloys

June 15, 2021
Author(s)
Md Abdullah Al Hasan, Jiaqi Wang, Seungha Shin, Dustin A. Gilbert, Peter K. Liaw, Nan Tang, W. L. N. C. Liyanage, Louis Santodonato, Lisa Debeer-Schmitt, Nicholas Butch
Introducing a non-regular distribution in the mass and bonding by including distinctly different elements can reduce the phonon transport even within structurally well-ordered materials. These distributions are a quality of all high-entropy alloys (HEAs)

Hydroxyl radical is a significant player in oxidative DNA damage in vivo.

June 15, 2021
Author(s)
Miral M. Dizdar, Barry Halliwell, Amitav Adhikary, Michael Dingfelder
Recent publications have suggested that oxidative DNA damage mediated by hydroxyl radical (.OH) is unimportant in vivo, and that carbonate anion radical (CO3.-) plays the key role. We examine these claims and summarize the evidence that OH does play a key

LIQUID FLOW METER CALIBRATIONS WITH NIST's 15 kg/s WATER FLOW STANDARD

June 15, 2021
Author(s)
Jodie Gail Pope, Aaron Johnson, James Filla, Vern E. Bean, Michael R. Moldover, Joey Boyd, Christopher J. Crowley, Iosif Isaakovich Shinder, Keith A. Gillis, John D. Wright
We describe the 15 kg/s water flow calibration standard operated by the Fluid Metrology Group of the National Institute of Standards and Technology (NIST) to calibrate liquid flow meters for customers. The 15 kg/s standard is a dynamic, gravimetric, liquid

Machine-learning enhanced dark soliton detection in Bose-Einstein condensates

June 15, 2021
Author(s)
Shangjie Guo, Amilson R. Fritsch, Ian Spielman, Justyna Zwolak
Most data in cold-atom experiments comes from images, the analysis of which is limited by our preconceptions of the patterns that could be present in the data. We focus on the well-defined case of detecting dark solitons—appearing as local density

Sea turtles across the North Pacific are exposed to perfluoroalkyl substances

June 15, 2021
Author(s)
Cathryn Wood, George H. Balazs, Marc Rice, Thierry M. Work, T. T. Jones, Eleanor Sterling, Tammy Summers, John Brooker, Lauren Kurpita, Cheryl King, Jennifer Lynch
Perfluorinated alkyl substances (PFASs) are global, persistent, and toxic contaminants. We assessed PFAS concentrations in green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles from the North Pacific. Fifteen compounds were quantified via

The Thermal Character of a 1 m Methanol Pool Fire

June 15, 2021
Author(s)
Kunhyuk Sung, Jian Chen, Matthew Bundy, Marco G. Fernandez, Anthony Hamins
This is the second edition of this study, which presents a series of measurements conducted to characterize the structure of a 1 m diameter methanol pool fire steadily burning with a constant lip height in a well-ventilated quiescent environment. The main

A Pseudo Exhaustive Software Testing Framework for Embedded Digital Devices in Nuclear Power

June 14, 2021
Author(s)
Athira Jayakumar, D. Richard Kuhn, Brandon Simons, Aidan Collins, Smitha Gautham, Richard Hite, Raghu N. Kacker, Abhi Rajagopala, Carl Elks
The major challenge faced by the nuclear industry related to software testing of digital embedded devices is the identification of practical software (SW) testing solutions that provide a strong technical basis and is at the same time effective in

Ne-22 Ion-Beam Radiation Damage to DNA: From Initial Free Radical Formation to Resulting DNA-Base Damage

June 14, 2021
Author(s)
Melis Kant, Pawel Jaruga, Erdem Coskun, Samuel Ward, Alexander Stark, Thomas Baumann, David Becker, Amitava Adhikary, Michael Sevilla, Miral M. Dizdar
We report on the physicochemical processes and the products of DNA damage involved in Ne-22 ion-beam radiation of hydrated (12±3 H2O/nucleotide) salmon sperm DNA at 77 K. Free radicals trapped at 77 K were identified using electron spin resonance (ESR)

Securing AI Testbed (Dioptra) Documentation

June 14, 2021
Author(s)
Harold Booth, James Glasbrenner, Howard Huang, Cory Miniter, Julian Sexton
The NCCoE has built an experimentation testbed to begin to address the broader challenge of evaluation for attacks and defenses. The testbed aims to facilitate security evaluations of ML algorithms under a diverse set of conditions. To that end, it has a

Texture Evolution as a Function of Scan Strategy and Build Height in Electron Beam Melted Ti-6Al-4V

June 12, 2021
Author(s)
Alec Saville, Sven Vogel, Adam Creuziger, Jake Benzing, Adam Pilchak, Lee Semiatin, Peeyush Nandwana, Kester Clarke, Jonah Klemm-Toole, Amy Clarke
Metal additive manufacturing (AM) enables customizable, on-demand parts, allowing for new designs and improved engineering performance. Unfortunately, the ability to control AM metal alloy microstructures is still lacking, especially when considering

Database of Ab Initio L-edge X-ray Absorption Near Edge Structure

June 11, 2021
Author(s)
Yiming Chen, Chi Chen, Chen Zheng, Shyam Dwaraknath, Matthew K. Horton, Jordi Cabana, John J. Rehr, John Vinson, Alan K. Dozier, Kristin A. Persson, Shyue P. Ong
The L-edge X-ray Absorption Near Edge Structure (XANES) is widely used in the characterization of transition metal compounds. Here, we report the development of a database of computed L-edge XANES using the multiple scattering theory-based FEFF9 code. The

Field-induced dehydration and optimal ionic escape paths for C2N membranes

June 11, 2021
Author(s)
Miroslav Barabash, William Gibby, Dmitry Luchinsky, Binquan Luan, Alexander Smolyanitsky, Peter McClintock
Most analytic theories describing electrostatically driven ion transport through water-filled nanopores assume that the corresponding permeation barriers are bias-independent. While this assumption may hold for sufficiently wide pores under infinitely

Improvement of the spectroscopic parameters of the air- and self-broadened N2O and CO lines for the HITRAN2020 database applications

June 11, 2021
Author(s)
Robab Hashemi, Iouli Gordon, Erin Adkins, Joseph T. Hodges, Manfred Birk, David Long, Chris Boone, Adam Fleisher, Adriana Predoi-Cross, Laurence Rothman
This paper outlines the major update of the line-shape parameters that were performed for the nitrous oxide (N2O) and carbon monoxide (CO) molecules listed in the HITRAN2020 database. We reviewed the collected measurements for the air- and self-broadened

Measuring Deadtime and Double-Counts in a Non-Paralyzable Scintillating Neutron Detector using Arrival Time Statistics

June 11, 2021
Author(s)
Kevin N. Pritchard, Jean Philippe Chabot, Peter Tsai, R. Roubucci, F. S. Choa, A. Osovizky, Jeffrey B. Ziegler, Louis E. Binkley, Nancy Hadad, M. Jackson, C. Hurlbut, George M. Baltic, Charles Majkrzak, Nicholas C. Maliszewskyj
A 6LiF:ZnS(Ag) based cold neutron detector with wavelength shifting (WLS) fibers and SiPM photodetector was developed at the NIST Center for Neutron Research for the CANDoR instrument (Chromatic Analysis Neutron Diffractometer or Reflectometer). The

Molecular Mass Dependence of Interfacial Tension in Complex Coacervation

June 11, 2021
Author(s)
Debra Audus, Samim Ali, Artem Rumyantsev, Yuanchi Ma, Juan J. de Pablo, Vivek Prabhu
The interfacial tension of coacervates, the liquidlike phase composed of oppositely charged polymers that coexists at equilibrium with a supernatant, forms the basis for multiple technologies. Here we present a comprehensive set of experiments and

Trace element proxies and stable isotopes used to identify water quality threats to elkhorn coral (Acropora palmata) at two national parks in St. Croix, USVI

June 11, 2021
Author(s)
Amanda L. Bayless, Steven J. Christopher, Jennifer Ness, Colleen E. Bryan Sallee, Russell D. Day, Cheryl M. Woodley, C. Anna Toline
Chronic biological impairments of reef organisms have been documented at two national parks in St. Croix, USVI. Although several water quality parameters have been out of compliance with USVI water quality criteria, whether these parameters or other
Displaying 4376 - 4400 of 74084