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Search Publications

NIST Authors in Bold

Displaying 26 - 50 of 2724

Elucidating the thermal properties and anomalous transport in the 18R polytype of SnSe2

May 30, 2025
Author(s)
Oluwagbemiga Ojo, Wilarachchige D. C. B. Gunatilleke, Winnie Wong-Ng, Tieyan Chang, Yu-Sheng Chen, Joshua Martin, Adam Biacchi, George Nolas
The 18R polytype of SnSe2 possesses unique structural features that can directly impact the transport properties and potential applications of interest; however, a comprehensive understanding of the intrinsic physical properties is lacking. We grew large

Elongated particles in flow: commentary on small-angle scattering investigations

May 23, 2025
Author(s)
Guan-Rong Huang, Lionel Porcar, Ryan Murphy, Yuya Shinohara, Yangyang Wang, Jan-Michael Carrillo, Bobby G. Sumpter, Chi-Huan Tung, Lijie Ding, Changwoo Do, Wei-Ren Chen
This work thoroughly examines several analytical tools, each possessing a different level of mathematical intricacy, for the purpose of characterizing the orientation distribution function of elongated objects under flow. Our investigation places an

Towards an Understanding of Robotic Bin-Picking Throughput

May 22, 2025
Author(s)
Anirudh Krishnan Komaralingam, Prem Rachakonda, Kamel Saidi, Armin Khatoonabadi
NIST is leading and supporting multiple efforts to develop standards for 3D imaging systems used for industrial automation. There are few standards for verifying the performance of these systems and NIST is working with ASTM subcommittee E57.23 on

The SIM Time Network - Twenty Years of Operation

May 16, 2025
Author(s)
Andrew Novick, Jose Mauricio Lopez Romero
The SIM Time Network (SIMTN) was established two decades ago to provide real-time time and frequency comparisons among National Metrology Institutes (NMIs) across the Americas. Since its inception, SIMTN has played a crucial role in strengthening regional

NIST Special Publication 260 NIST.SP.260-256 Certification of Standard Reference Material(R)s 3672a & 3673a: Organic Contaminants in Smokers' Urine (Frozen) & Organic Contaminants in Non-Smokers' Urine (Frozen)

May 14, 2025
Author(s)
Ashley Russell, Carolyn Burdette, Johanna Camara, Nathanael Heckert, Jennifer Hoguet, Kevin Huncik, Jared Ragland, Elena Wood
Standard Reference Material (SRM) 3672a Organic Contaminants in Smokers' Urine (Frozen) and SRM 3673a Organic Contaminants in Non-Smokers' Urine (Frozen) are intended for use in evaluating analytical methods for the determination of selected naturally

Certification of Standard Reference Material(R) 1989 Monodisperse Irregularly Shaped Epoxy-Based Particles (Nominal 100 mm, 150 mm, 220 mm)

May 2, 2025
Author(s)
Srivalli Telikepalli, Dean Ripple, Michael Carrier, Kristen Steffens, David Newton, Christopher Montgomery, Nicholas Ritchie, Anthony Asmar, Michael Halter
Standard Reference Material (SRM) 1989 is a NIST particle standard produced using photolithographic methods and delivers a certified value for particle size of an irregularly shaped particle. This SRM was developed to allow a more accurate monitoring of

CODATA Recommended Values of the Fundamental Physical Constants: 2022

April 30, 2025
Author(s)
Peter Mohr, David Newell, Barry N. Taylor, Eite Tiesinga
We report the 2022 self-consistent values of constants and conversion factors of physics and chemistry recommended by the Committee on Data of the International Science Council (CODATA). The recommended values can also be found at physics.nist.gov

Cannabis Laboratory Quality Assurance Program: Exercise 3 Moisture Final Report

April 28, 2025
Author(s)
Andrea Yarberry, Charles Barber, Laura Wood, Walter Wilson
NIST launched a Cannabis Laboratory Quality Assurance Program (CannaQAP) in 2020 to assist laboratories in demonstrating and improving cannabis (hemp and marijuana) measurement comparability and competence. CannaQAP provided tools that allowed analysts and

Interlaboratory Assessment of Candidate Reference Materials for Lentiviral Vector Copy Number and Integration Site Measurements

April 21, 2025
Author(s)
Hua-Jun He, Zhiyong He, Steven Lund, Barbara Paugh, Jennifer McDaniel, Justin Zook, Sierra Miller, Samantha Maragh, Simona Patange, Mahir Mohiuddin, Alessandro Tona, John Elliott, Kenneth Cole, Sheng Lin-Gibson
Reference materials are essential for accurately measuring integrated lentiviral vector (LV) copy number (VCN) and integration sites for the safety and efficacy of lentivirus-based gene therapy. We conducted an interlaboratory study on NIST candidate

Investigating the factors that influence 3D stereo depth sensor noise

April 18, 2025
Author(s)
Terrence Pierce, Prem Rachakonda
3D stereo depth sensors have a variety of applications, including sensing for autonomous vehicles, reverse engineering, and manufacturing automation. The performance of these sensors can be affected by various factors, such as sensor construction, sensor

Investigating the factors that influence 3D stereo depth sensor noise

April 18, 2025
Author(s)
Terrence Pierce, Prem Rachakonda
3D stereo depth sensors have a variety of applications, including sensing for autonomous vehicles, reverse engineering, and manufacturing automation. The performance of these sensors can be affected by various factors, such as sensor construction, sensor

Compact Blackbody Radiation Atomic Sensor: Measuring Temperature using Optically Excited Atoms in Vapor Cells

April 17, 2025
Author(s)
David La Mantia, Mingxin Lei, Nikunjkumar Prajapati, Noah Schlossberger, Matthew Simons, Christopher Holloway, Julia Scherschligt, Stephen Eckel, Eric Norrgard
We demonstrate a blackbody radiation thermometer based on optically excited rubidium atoms in a vapor cell. Operating as a calibrated contact thermometer from 308K to 343 K, we realize temperature uncertainty as low as 0.04 %, and statistical temperature

Manipulation of meniscus rise for in situ multiphase nuclear magnetic resonance spectroscopy

April 8, 2025
Author(s)
Veruska Malave, Newell Moser, Edward Garboczi, Mark McLinden, Jason Widegren, Christopher Suiter
Our earlier work demonstrated that nuclear magnetic resonance (NMR) spectroscopy is a viable technique for in situ analysis of vapor–liquid equilibria (VLE) of fluid mixtures and that inserting a capillary into the NMR sample tube allows the simultaneous

Laser Beam Metrology for AM-Bench 2022: Approaches, Results, and Lessons Learned

April 1, 2025
Author(s)
David Deisenroth, Jordan Weaver, Sergey Mekhontsev, Steven Grantham, Shawn P. Moylan
One of key parameters of additive manufacturing by laser powder bed fusion of metal parts (PBF-LB/M) is the power density distribution (PDD) of the process laser beam. This paper describes the methods used to measure the beam PDD, discussing well

A method to calibrate angular positioning errors using a laser tracker and a plane mirror

March 20, 2025
Author(s)
Balasubramanian Muralikrishnan, Katharine Shilling, Vincent Lee, Olga Ridzel, Glenn Holland, John Villarrubia
We describe a method to calibrate angular positioning errors of a rotation stage using a laser tracker (LT), a plane mirror mounted on the stage, and stationary registration nests placed around the stage. Our technique involves determining the direction of

BRDF measurements of ultra-black materials with THz quantum cascade lasers

March 19, 2025
Author(s)
Patrick McArdle, Bradley Pelz, Christopher Yung, Nathan Tomlin, John Lehman, Michelle Stephens
In this work we describe the use of a THz quantum cascade laser (QCL) to perform bi-directional reflectance distribution (BRDF) measurements. In particular we are interested in the reflectance properties of ultra-black absorbers for use in detector devices

Modulated Laser Thermal Interrogation (MLTI): A Novel In Situ Metal Powder Evaluation Technique for Laser Powder Bed Fusion

March 1, 2025
Author(s)
Sina Ghadi, Xiaobo Chen, Nicholas Tomasello, Nicholas Derimow, Srikanth Rangarajan, Guangwen Zhou, Scott Schiffres
Assessment of metal powders in powder bed additive manufacturing is crucial, as the quality of the powders significantly impacts the final printed parts. This study introduces a novel technique to characterize metal powders by analyzing changes in their

Product ion distributions using H3O+ proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS): mechanisms, transmission effects, and instrument-to-instrument variability

February 27, 2025
Author(s)
Michael Link, Megan Claflin, Christina Cecelski, Ayomide Akande, Delany Kilgour, Paul Heine, Matthew Coggon, Chelsea Stockwell, Andrew Jensen, Jie Yu, Han Huyhn, Jenna Ditto, Carnsten Warneke, William Dresser, Keighan Gemmell, Spiro Jorga, Rileigh Robertson, Joost de Gouw, Timothy Bertram, Jonathan Abbatt, Nadine Borduas-Dedekind, Dustin Poppendieck
Proton-transfer-reaction mass spectrometry (PTR-MS) using hydronium ion (H3O+) ionization is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. H3O+ ionization, as well as the associated chemistry in an ion
Displaying 26 - 50 of 2724
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