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The cryogenic current comparator is used to maintain national representations of the ohm based on the quantized Hall resistance standard. The measurement technique utilizes the Meissner effect to establish accurate resistance ratios with specialized
Andrei A. Kolmakov, Luca Gregoratti, Maya Kiskinova, Sebastian Gunther
Ambient pressure photoelectron spectroscopy (APPES) and microscopy are at the frontier of modern chemical analysis at liquid-gas, solid-liquid and solid-gas interfaces, bridging science and engineering of functional materials. Complementing the current
Sidewall sensing in CD-AFMs usually involves continuous lateral dithering of the tip or the use of a control algorithm and fast response piezo actuator to position the tip in a manner that resembles touch-triggering of coordinate measuring machine (CMM)
Katharina-Sofie Isleif, Oliver Gerberding, Thomas Schwarze, Moritz Mehmet, Gerhard Heinzel, Felipe Guzman
Experiments for space and ground-based gravitational wave detectors often require large dynamic range interferometric position readout of test masses with 1 pm/√Hz precision over long time scales. Heterodyne interferometer schemes that achieve such
David W. Flater, Paul E. Black, Elizabeth N. Fong, Raghu N. Kacker, Vadim Okun, Stephen S. Wood, David R. Kuhn
Much software research and practice involves ostensible measurements of software, yet little progress has been made on an SI-like metrological foundation for those measurements since the work of Gray, Hogan, et al. in 1996-2001. Given a physical object
Aaron N. Johnson, Rodney A. Bryant, Tamae M. Wong, James R. Whetstone, Eric Harman, Woong Kang, Keith A. Gillis, Hsin-Hung Lee, Iosif I. Shinder, Liang Zhang
On April 20-21, 2015, NIST hosted a workshop that, through measurement science, enabled the owners of stationary sources (primarily the electric power industry) and their regulatory agencies (federal and state) to better characterize greenhouse gas (GHG)
Behrang H. Hamadani, Andrew M. Shore, John F. Roller, Howard W. Yoon, Mark Campanelli
We present a light emitting diode (LED)-based system utilizing a combinatorial flux addition method to investigate the nonlinear relationship in solar cells between the output current of the cell and the incident irradiance level. The magnitude of the
We have developed a custom apparatus for the consecutive measurement of the electrical resistivity, the Seebeck coefficient, and the thermal conductivity of materials between 300 K and 12 K. These three transport properties provide for a basic
Guangjun Cheng, Christina A. Hacker, Curt A. Richter, Angela R. Hight Walker
We present an investigation on the etching of graphite catalyzed by the particles produced by dewetting Fe thin films on graphite in forming gas. Raman mapping of the etched graphite shows the thickness variation in the etched channels and reveals that the
Joseph A. Falco, Jeremy A. Marvel, Richard J. Norcross, Karl Van Wyk
Metrics and test methods are needed to characterize the control capabilities of robots with both intrinsic and extrinsic force sensing. The availability of these benchmarks will motivate research product development, and provide a mechanism for reporting
A cavity ring-down spectrometer and condensation particle counter were used to investigate the limitations in the separation of singly and multiply charged aerosol particles by a tandem differential mobility analyzer (DMA) and aerosol particle mass
Michael R. Moldover, Weston L. Tew, Howard W. Yoon
The last 25 years have seen tremendous progress in thermometry in the moderate temperature range (1 K to 1235 K). Various primary thermometers based on different physics have uncovered errors in the International Temperature Scale of 1990 and set the
Compressed-liquid densities of three compositions of the binary mixture dimethyl ether (CAS No. 115-10-6) + pentane (CAS No. 109-66-0) have been measured with a vibrating U-tube densimeter. Measurements were made at temperatures from 270 K to 390 K with
Kathryn E. Keenan, Sheye O. Aliu, Lisa J. Wilmes, David C. Newitt, Ella F. Jones, Wen Li, Michael A. Boss, Nola M. Hylton
Purpose: We present a breast phantom designed to enable quantitative assessment of measurements of T 1 relaxation time, apparent diffusion coefficient (ADC), and other attributes of breast tissue, with long-term support from a national metrology institute
Roger V. Bostelman, Joseph A. Falco, Milli Shah, Tsai H. Hong
Multi-camera motion capture systems are commercially available and are typically used in the entertainment industry to track human motions for video gaming and movies. These systems are proving useful as ground truth measurement systems to assess the
Ndubuisi G. Orji, Hiroshi Itoh, Chumei Wang, Ronald G. Dixson, Sebastian Schmidt, Bernd Irmer, Peter S. Walecki
In atomic force microscopy (AFM) metrology, the tip is a key source of uncertainty. Images taken with an AFM show a change in feature width and shape that depends on tip geometry. This geometric distortion is more pronounced when measuring features with
Deogratias Kibira, Katherine C. Morris, Senthilkumaran Kumaraguru
The emerging concept of smart manufacturing systems is defined in part by the introduction of new technologies that are promoting rapid and widespread information flow within the manufacturing system and surrounding its control. These systems can deliver
Yvonne B. Gerbig, Chris A. Michaels, Robert F. Cook, Jodie E. Bradby
Indentation-induced plastic deformation of amorphous silicon (a-Si) thin films was studied by in situ Raman imaging of the deformed contact region of an indented sample, employing a Raman spectroscopy-enhanced instrumented indentation technique (IIT). The
The NIST Office of Weights and Measures (OWM) over time have received a number of inquiries regarding the suitability, use, and testing of hopper-type scales. The nature of those inquiries provides some indication that there is a lack of detailed
Rainer Feistel, Robert Wielgosz, Stephanie A. Bell, M F. Camoes, J R. Cooper, P Dexter, A G. Dickson, P Fisicaro, Allan H. Harvey, M Heinonen, Olaf Hellmuth, H J. Kretzschmar, J W. Lovell-Smith, Trevor J. McDougall, R Pawlowicz, S Seitz, Petra Spitzer, D Stoica, H Wolf, P Ridout
Water in its three ambient phases plays the dominant thermodynamic role for the functioning principles of the terrestrial climate system. Together with clouds, water vapour in the atmosphere is the strongest greenhouse gas (followed by clouds and carbon
Grady S. White, Adrian Verwolf, Chris M. Poling, Nicholas Barbosa, Nikki S. Rentz
Silicon wafers with micro-machined holes were evaluated for use as low permeation standard artifacts. Accuracy, stability, and reliability were assessed. Two experimental techniques were used: chilled mirror hygrometer and mass loss. The wafers exhibited a