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Metrology

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Displaying 901 - 925 of 2718

Monitoring Techniques for the Net-Zero Energy Residential Test Facility

December 31, 2014
Author(s)
Mark W. Davis, William M. Healy, Matthew Boyd, Lisa Ng, William V. Payne, Harrison Skye, Tania Ullah
NIST has constructed a Net-Zero Energy Residential Test Facility that will be used as a testbed for investigating the measurement science related to systems, components, and operations that will lead to homes that generate as much energy over a course of a

Quantitative, label-free characterization of stem cell differentiation at the single-cell level by broadband coherent anti-Stokes Raman scattering microscopy

December 31, 2014
Author(s)
Marcus T. Cicerone, Young J. Lee, Khaled A. Aamer, Prabhas V. Moghe, Sebastian L. Vega, Parth J. Patel
We use broadband coherent anti-Stokes Raman scattering (BCARS) microscopy to characterize lineage commitment of individual human mesenchymal stem cells (hMSCs) cultured in adipogenic, osteogenic, and basal culture media. We treat hyperspectral images

NIST Micronutrients Measurement Quality Assurance Program Winter, Spring, and Fall 1992 Comparability Studies: Results for Round Robins XXIV, XXV, and XXVI Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 3 Ascorbic Acid in Human Serum

December 19, 2014
Author(s)
Jeanice M. Brown Thomas, Neal E. Craft, David L. Duewer, Kline Margaret, Sam A. Margolis, Willie E. May, Katherine E. Sharpless
The National Institute of Standards and Technology coordinates the Micronutrients Measurement Quality Assurance Program (MMQAP) for laboratories that measure fat- and water-soluble vitamins and carotenoids in human serum and plasma. This report describes

NIST Micronutrients Measurement Quality Assurance Program Winter, Spring, and Fall 1993 Comparability Studies: Results for Round Robins XXVII, XXVIII, and XXIX Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 4 Ascorbic Acid in Human Se

December 19, 2014
Author(s)
Jeanice M. Brown Thomas, David L. Duewer, Kline Margaret, Sam A. Margolis, Willie E. May, Katherine E. Sharpless
The National Institute of Standards and Technology coordinates the Micronutrients Measurement Quality Assurance Program (MMQAP) for laboratories that measure fat- and water-soluble vitamins and carotenoids in human serum and plasma. This report describes

CHAPTER 2: Experimental Techniques 1: Direct Methods

December 17, 2014
Author(s)
Mark O. McLinden
Fluid density is mass per unit volume, and the experimental techniques described in this chapter involve, in one way or another, a clearly defined mass and volume. For this reason, we describe them as “direct” methods. This is in contrast to the vibrating

CHAPTER 4: Density Standards and Traceability

December 17, 2014
Author(s)
Mark O. McLinden
Most instruments for measuring fluid density are not absolute instruments—they must be calibrated with one or more fluids of known density. The selection of appropriate calibration fluids is vital to achieving low uncertainty in a measurement. Also

In-situ Temperature Calibration Capability for Dimensional Metrology

December 15, 2014
Author(s)
Prem K. Rachakonda, Daniel S. Sawyer, Balasubramanian Muralikrishnan, Christopher J. Blackburn, Craig M. Shakarji, Gregory F. Strouse, Steven D. Phillips
The Dimensional Metrology Group (DMG) at the National Institute of Standards and Technology (NIST) has developed a new in-situ temperature calibration system. This paper discusses the system components, an in-situ calibration procedure, the uncertainty

Biomass Particle Models with Realistic Morphology and Resolved Microstructure for Simulations of Intraparticle Transport Phenomena

December 9, 2014
Author(s)
Peter Ciesielski, Michael F. Crowley, M R. Nimlos, Aric Sanders, Gavin Wiggins, Bryon Donohoe
Biomass exhibits a complex microstructure of directional pores that can vary substantially between species of origin. However, models of biomass particles employed in simulations of conversion processes typically employ over-simplified geometry such as

Improvements to NISTs Air Speed Calibration Service

December 8, 2014
Author(s)
Iosif I. Shinder, Michael R. Moldover, Christopher J. Crowley, Bernard J. Filla
We discuss five significant improvements to the Air Speed Calibration Service conducted by the National Institute of Standards and Technology (NIST): 1. Reduced-uncertainty calibration of the secondary standard [Laser Doppler Anemometer, (LDA)] using a

In-situ Temperature Calibration Capability for Dimensional Metrology

December 1, 2014
Author(s)
Prem K. Rachakonda, Daniel S. Sawyer, Balasubramanian Muralikrishnan, Christopher J. Blackburn, Craig M. Shakarji, Gregory F. Strouse, Steven D. Phillips
The Dimensional Metrology Group (DMG) at the National Institute of Standards and Technology (NIST) has the capability to perform large range dimensional measurements in a facility, called the Tape Tunnel. The Tape Tunnel is equipped with a 60 m long steel

Principles of Optical Radiometry and Measurement Uncertainty

November 27, 2014
Author(s)
Bettye C. Johnson, Howard W. Yoon, Joseph P. Rice, Albert C. Parr
The fundamental concepts of optical radiometry are developed from basic principles, with detailed explanations for radiance, irradiance, and reflectance. Examples of radiometric standards, in particular radiometers and reference sources are given, and the

Electron and Hole Photoemission Detection for Band Offset Determination of Tunnel Field-Effect Transistor Heterojunctions

November 24, 2014
Author(s)
Wei Li, Qin Zhang, R. Bijesh, Oleg A. Kirillov, Yiran Liang, Igor Levin, Lianmao Peng, Xuelei Liang, S. Datta, David J. Gundlach, Nhan V. Nguyen
The electrical performance of a tunnel field-effect transistor depends critically on the band offset at their semiconductor heterojunction interface. Historically, it has been difficult to experimentally determine how the electronic bands align at the

Diode-array UV solar spectroradiometer implementing a digital micromirror device

November 20, 2014
Author(s)
Ari D. Feldman, Tim Burnitt, Geiland Porrovecchio, Marek Smid, Luca Egli, Julian Gr?bner, Katherine M. Nield
The solar ultraviolet spectrum captured by commercially available diode-array spectroradiometers is dominated by stray light from longer wavelengths with higher intensity. The implementation of a digital micromirror device in an array spectroradiometer has

Accurate determination of the size distribution for polydisperse, cationic metallic nanomaterials by asymmetric-flow field flow fractionation

November 13, 2014
Author(s)
Julien C. Gigault, Thao M. Nguyen, John M. Pettibone, Vincent A. Hackley
In this work we have developed and validated a methodology for determining the size distribution in polydisperse cationic nanoparticle (NP) samples using asymmetric-flow field flow fractionation (A4F), where known compositional influence of previously used

Influence of the central mode and soft phonon on the microwave dielectric loss near the strain-induced ferroelectric phase transitions in Sr n+1 uTi n uO 3n+1 u*

November 12, 2014
Author(s)
V. Goian, S. Kamba, D Nuzhnyy, Nathan Orloff, T. Birol, C.-H Lee, D. G. Schlom, James Booth
Recently, Lee et al. [1] used1% tensile strain to induce a ferroelectic instability in thin films of Srdn+1uTi nuO 3n+1u (n=1-6) phases. They showed that the Curie temperature T cu gradually increased with n, reaching 180 K for Sr7Ti6O19 (n=6). The

A Method of Determining Sphere Center to Center Distance Using Laser Trackers For Evaluating Laser Scanners.

November 11, 2014
Author(s)
Prem K. Rachakonda, Balasubramanian Muralikrishnan, Vincent D. Lee, Daniel S. Sawyer, Steven D. Phillips, John Palmateer
The Dimensional Metrology Group (DMG) at the National Institute of Standards and Technology (NIST) is involved in the development of documentary standards for volumetric performance evaluation of laser scanners. Typical evaluation of these scanners
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