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Search Publications

NIST Authors in Bold

Displaying 2326 - 2350 of 73697

Flame Propagation in Blends of R152a, R134a, and R-1234yf with Air

September 13, 2023
Author(s)
Dennis Kim, Valeri I. Babushok, Michael Hegetschweiler, Gregory T. Linteris
Laminar burning velocity measurements have been made using a constant volume experiment with dry air and the refrigerant R152a (CH3CHF2), pure and blended with R134a (CH2FCF3), or R1234yf (CF3CFCH2). The resulting burning velocity data deduced from the

Ab initio Calculation of Fluid Properties for Precision Metrology

September 12, 2023
Author(s)
Giovanni Garberoglio, Christof Gaiser, Roberto Maria Gavioso, Allan H. Harvey, Robert Hellmann, Bogumil Jeziorski, Karsten Meier, Michael R. Moldover, Laurent Pitre, Krzysztof Szalewicz, Robin Underwood
Recent advances regarding the interplay between ab initio calculations and metrology are reviewed, with particular emphasis on gas-based techniques used for temperature and pressure measurements. Since roughly 2010, several thermophysical quantities – in

CCQM_Retrospectoscope Reference Manual: A detailed reference to the CCQM_Retrospectoscope, a suite of graphical tools for the meta-analysis of measurement results from CCQM studies

September 12, 2023
Author(s)
David L. Duewer, Michael Nelson, Christina Cecelski
The CCQM_Retrospectoscope system combines a nominally complete database of results from Consultative Committee for the Amount of Substance: Metrology in Chemistry and Biology (CCQM) studies with a number of graphical tools for trying to make sense of the

Comparison of the detection efficiency calibration of a single-photon avalanche detector between NIST and PTB

September 12, 2023
Author(s)
Hristina Georgieva, Thomas Gerrits, Helmuth Hofer, Anouar Rahmouni, Oliver T. Slattery, Marco Lopez, Joshua Bienfang, Alan Migdall, Stefan Kueck
The detection efficiency of a commercial single-photon avalanche detector (SPAD) has been independently determined at two national metrology institutes, the National Institute of Standards and Technology (NIST) - USA and the Physikalisch-Technische

Repeatability of Contactless and Contact Fingerprint Capture

September 12, 2023
Author(s)
John M. Libert, Shahram Orandi, John Grantham, Kenneth Ko, Bruce Bandini
A new generation of contactless fingerprint capture devices has recently emerged. These devices provide the ability to capture a fingerprint without making physical contact with the finger. There is anecdotal evidence that the process of capturing a

Constraints on Proximity-Induced Ferromagnetism in a Dirac Semimetal (Cd3As2)/Ferromagnetic Semiconductor (Ga1-xMnxSb) Heterostructure

September 11, 2023
Author(s)
Arpita Mitra, Run Xiao, Wilson Yanez, Yongxi Ou, Juan Chamorro, Tyrel M. McQueen, Alexander Grutter, Julie A. Borchers, Michael R. Fitzsimmons, Timothy Charlton, Nitin Samarth
Breaking time-reversal symmetry in a Dirac semimetal Cd3As2 through doping with magnetic ions or by the magnetic proximity effect is expected to cause a transition to other topological phases (such as a Weyl semimetal). To this end, we investigate the

High-Power Radiation-Pressure-based Laser Metrology Using an Electrostatic Force Balance

September 11, 2023
Author(s)
Brian Simonds, Kyle Rogers, Sven Schulze, David Newell, Gordon Shaw, John Lehman, Paul A. Williams
A primary standard electrostatic force balance has been integrated into a multiple-reflection radiation pressure-based laser power meter capable of measuring kilowatts of optical power. We present optical power data at 0.1 kW, 1 kW, 2 kW, and 5 kW with the

Laser Power Accuracy of Additive Manufacturing Systems - A Round Robin Study

September 11, 2023
Author(s)
Brian Simonds, Kyle Rogers, Paul A. Williams
High power lasers are at the core of metal additive manufacturing (AM) systems and the accurate delivery of laser energy is critical to part performance. We have performed a round robin style survey of U.S. AM equipment across industry, academia, and

Non-flammable Low-GWP Refrigerant Blends to Replace HFC-134a

September 11, 2023
Author(s)
Harrison M. Skye, Piotr A. Domanski, Mark O. McLinden, Valeri I. Babushok, Ian Bell, Tara Fortin, Michael Hegetschweiler, Mark A. Kedzierski, Dennis Kim, Lingnan Lin, Gregory T. Linteris, Stephanie L. Outcalt, Vance (Wm.) Payne, Richard A. Perkins, Aaron Rowane
Non-flammable, lower global-warming-potential (GWP) refrigerants are needed to replace HFC-134a (GWP=1300) in military equipment. We previously used thermodynamic cycle simulations to screen 100 000+ refrigerant blends and identified 23 candidate

Pore Modulation of Hydrogen-Bonded Organic Frameworks for Efficient Separation of Propylene

September 11, 2023
Author(s)
Youlie Cai, Junkuo Gao, Jing-Hong Li, Puxu Liu, Yanchun Zheng, Wei Zhou, Hui Wu, Libo Li, Rui-Biao Lin, Banglin Chen
Developing hydrogen-bonded organic frameworks (HOFs) that combine functional sites, size control, and storage capability for targeting gas molecule capture is a novel and challenging venture. However, there is a lack of effective strategies to tune the

Target and Suspect Screening Integrated with Machine Learning to Discover Per- and Polyfluoroalkyl Substance Source Fingerprints

September 11, 2023
Author(s)
Nayantara Joseph, Trever Schwichtenberg, Dunping Cao, Gerrad Jones, Alix Rodowa, Joe Charbonnet, Christopher Higgins, Damian Helbling, Jennifer Field
This study elucidates per- and polyfluoroalkyl substance (PFAS) fingerprints for specific PFAS source types. Ninety-two samples were collected from aqueous film-forming foam impacted groundwater (AFFF-GW), landfill leachate, biosolids leachate, municipal

Evaluation of 3D Curvature and Lead Stress of Transvenous Right Ventricular Leads: The Human Use Conditions Study (HUCS)

September 9, 2023
Author(s)
Jonathan Piccini, Tim Quinn, Lucas Koepke, James Dawson, Nicki Mara, Jason Santelli, Diane Muff, Jordan Savela, Alex Felber, Michael Friedrich, Jens Rump, Felix Tschentscher, Jake Benzing, Charles Swerdlow
Transvenous leads of cardiac implanted electronic device (CIED) systems are meant to last the life of the patient, but they are at risk for conductor fatigue fracture from applied alternating stress. This stress depends on lead design and use conditions

Gravimetric deposition of microliter drops with radiometric confirmation

September 9, 2023
Author(s)
Denis E. Bergeron, Richard Essex, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren, Ryan P. Fitzgerald
A manual gravimetric dispensing technique is demonstrated using a micropipettor modified for use with removeable microcapillaries. Liquid scintillation sources were prepared from a well-characterized 241Am reference solution, providing a radiometric check

Multi'omic Characterization of Human Whole Stool RGTMs

September 8, 2023
Author(s)
Amanda Bayless, Sandra Da Silva, William Davis, Abraham Kuri Cruz, Tracey Johnston, Stephanie Servetas, Paulina Piotrowski
The gut microbiome plays a critical role in a vast and disparate set of health and disease states, including cancer and obesity. Human fecal is a complex mixture including microbes, proteins, undigested plant matter and fat content according to the diet

Open-path measurement of stable water isotopologues using mid-infrared dual-comb spectroscopy

September 8, 2023
Author(s)
Daniel Herman, Griffin Mead, Fabrizio Giorgetta, Esther Baumann, Nathan Malarich, Brian Washburn, Nathan R. Newbury, Ian Coddington, Kevin Cossel
We present an open-path mid-infrared dual-comb spectrometer (DCS) capable of precise measurement of the stable water isotopologues H216O and HD16O. This system runs in a remote configuration at a rural test site with high uptime and achieves a precision of

Radiative Decay Rate and Branching Fractions of MgF

September 8, 2023
Author(s)
Eric Norrgard, Catherine Cooksey, Stephen Eckel, Nickolas Pilgram, Kayla Rodriguez, Howard W. Yoon, Yuly Andrea Chamorro Mena, Lukas Pasteka, Anastasia Borschevsky
Here we report measured and calculated values of radiative decay rates and vibrational branching fractions for the A$^2\Pi$ state of MgF. The decay rate measurements use time-correlated single photon counting with roughly 1\,\% total uncertainty. Branching

Simulations of a frequency-chirped magneto-optical trap of MgF

September 8, 2023
Author(s)
Kayla Rodriguez, Nickolas Pilgram, Daniel Barker, Stephen Eckel, Eric Norrgard
We simulate the capture process of MgF molecules into a frequency-chirped molecular MOT. Our calculations show that by chirping the frequency, the MOT capture velocity is increased by about of factor of 4 to 80m/s, allowing for direct loading from a two

In Situ Lignin Adhesion for High-Performance Bamboo Composites

September 7, 2023
Author(s)
Taotao Meng, Yu Ding, Yu Liu, Lin Xu, Yimin Mao, Julia Gelfond, Shuke Li, Zhihan Li, Paul Salipante, Hoon Kim, J. Zhu, Xuejun Pan, Liangbing Hu
Bamboo composite is an attractive candidate for structural materials in applications such as construction, the automotive industry, and logistics. However, its development has been hindered due to the use of harmful petroleum-derived synthetic adhesives or
Displaying 2326 - 2350 of 73697
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