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Displaying 51 - 75 of 2493

Versailles Project on Advanced Materials and Standards (VAMAS) Interlaboratory Study on Measuring the Number Concentration of colloidal gold nanoparticles

March 9, 2022
Caterina Minelli, Karen E. Murphy, Monique Johnson, Antonio Montoro Bustos, Jeffrey Fagan, Ingo Strenge
We describe the outcome of an international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced

ZKASP: ZKP-based Attestation of Software Possession for Measuring Instruments

March 9, 2022
Luis Brandao, Carlos Eduardo Cardoso Galhardo, Rene Peralta
Software-controlled measuring instruments used in commercial transactions, such as fuel dispensers and smart meters, are sometimes subject to "memory replacement" attacks. Cybercriminals replace the approved software by a malicious one that then tampers

Negative quasiprobabilities enhance phase estimation in quantum-optics experiment

March 1, 2022
Noah Lupu-Gladstein, Y. Batuhan Yilmaz, David Arvidsson-Shukur, Aharon Brodutch, Arthur Pang, Aephraim Steinberg, Nicole Halpern
Operator noncommutation, a hallmark of quantum theory, limits measurement precision, according to uncertainty principles. Wielded correctly, though, noncommutation can boost precision. A recent foundational result relates a metrological advantage with

Toward a New Primary Standardization of Radionuclide Massic Activity Using Microcalorimetry and Quantitative Milligram-Scale Samples

February 24, 2022
Ryan P. Fitzgerald, Bradley Alpert, Dan Becker, Denis E. Bergeron, Richard Essex, Kelsey Morgan, Svetlana Nour, Galen O'Neil, Dan Schmidt, Gordon A. Shaw, Daniel Swetz, R. Michael Verkouteren, Daikang Yan
We present a new paradigm for the primary standardization of radionuclide activity per mass of solution (Bq/g). Two key enabling capabilities are 4π decay-energy spectrometry using chip-scale sub-Kelvin microcalorimeters and direct realization of mass by

KEY COMPARISON - Instrumented Charpy tests on low- and high-energy specimens

February 18, 2022
Enrico Lucon, Renato Reis Machado
This report describes a CIPM Key Comparison through the SIM/MWG-7 organization, concerning instrumented impact testing of low-energy (20 J) and high-energy (100 J) Charpy V-notch specimens. In this Comparison, various instrumented and non-instrumented data

New reference materials for trace-levels of actinide elements in plutonium

January 27, 2022
Richard Essex, Lav Tandon, Amy Gaffney, Cole Hexel, Debbie Bostick, Lisa Colletti, Diana Decker, Casey Finstad, Joseph Giaquinito, Elmer Lujan, John Partridge, Benjamin Roach, John Rolinson, Kyle Samperton, Alice Slemmons, Khalil Spencer, Floyd Stanley, Lisa Townsend, Kerri Treinen, Ross Williams, Christopher Worley
Two plutonium oxides were prepared as unique reference materials for actinides occurring as trace constituents in Pu. Each reference material unit is approximately 200 mg of PuO2 in a quartz glass vial. Characterized attributes of the oxides included mass

Quantitative Determination of Cell Viability Using Absorbance Microscopy

January 19, 2022
Greta Babakhanova, Stephen Zimmerman, Laura Pierce, Sumona Sarkar, Nicholas Schaub, Carl Simon Jr.
Cell viability is an essential measurement for cell therapy products. One of the most common tests is Trypan blue (TB) dye exclusion where blue-stained cells are counted via imaging. Typically, live and dead cells are counted based on pixel intensities of

AbsorbanceQ: An App for Generating Absorbance Images from Brightfield Images

January 4, 2022
Stephen Zimmerman, Carl Simon Jr., Greta Babakhanova
The AbsorbanceQ app converts brightfield microscope images into absorbance images that can be analyzed and compared across different operators, microscopes and time. Absorbance-based measurements are comparable, which is useful when the aim is to

Mixture model analysis of Transition Edge Sensor pulse height spectra

December 9, 2021
Kevin J. Coakley, Jolene D. Splett, Thomas Gerrits
To calibrate an optical transition edge sensor, for each pulse of the light source (e.g., pulsed laser), one must determine the ratio of the expected number of photons that deposit energy and the expected number of photons created by the laser. Based on

HDX-MS and MD simulations provide evidence for stabilization of the IgG1- FcgRIa (CD64a) immune complex through intermolecular glycoprotein bonds

December 8, 2021
Kyle Anderson, Kerry Scott, Christina Bergonzo, Ioannis Karageorgos, Elyssia Gallagher, Venkata Tayi, Michael Butler, Jeffrey W. Hudgens
Previous reports present different models for the stabilization of the Fc—FcγRI immune complex. Although accord exists on the importance of L235 in IgG1 and some hydrophobic contacts for complex stabilization, discord exists regarding the existence of

A Comparison of Particle Size Distribution and Morphology Data acquired using Lab-based and Commercially Available Techniques: Application to Stainless Steel Powder

November 17, 2021
Justin Whiting, Edward Garboczi, Vipin Tondare, John Henry J. Scott, Alkan Donmez, Shawn P. Moylan
The particle size distribution (PSD) and particlemorphology ofmetal powders undoubtedly affects the quality of parts produced by additivemanufacturing (AM). It is, therefore, crucial to accurately knowthe PSD and morphology of these powders. There exist
Displaying 51 - 75 of 2493