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Efforts are underway in the Surface and Microanalysis Science Division at the National Institute of Standards and Technology to study the vapor transport mechanisms inside explosive trace detection instruments (ETD s) and produce standard test materials to
We are developing a mobile heterodyne terahertz system based on hot electron bolometer (HEB) mixer receivers to both image and obtain spectroscopic signatures from 2-D samples. An HEB provides unprecedented sensitivity and spectral resolution at terahertz
David J. Evans, Adriana Hornikova, Stefan D. Leigh, Andrew L. Rukhin, William E. Strawderman
The first regional key comparison in vibration conducted under the auspices of the Inter-American System of Metrology (SIM) was begun in 1996. The comparison was registered with the International Bureau of Weights and Measures (BIPM) through the
Jack A. Stone Jr., Jennifer Decker, Patrick Gill, Andrew Lewis, Patrick Juncar, Daniele Rovera, Miguel Villiseid
The Consultative Committee for Length has recommended that red (633 nm) unstabilized Helium-Neon lasers, operating on the 3s2¿_2p4 transition, should be included in the list of standard frequencies for realization of the meter. This article discusses
Analysis of droplet formation in microfluidic systems is important to understand the operation of these devices, and to permit optimal design and process control. Droplet formation in microfluidic T-junction devices was studied using experimental and
We have developed a software feedback loop that stabilizes the RF power input in calorimetric measurements to better than 30 ppm. In this system, a bolometric sensor with a Type IV power meter is used to detect the power. Feedback is provided to the AM
A method is presented for achieving high entrapment efficiencies of a hydrophilic drug simulant, sulforhodamine B (SRB), in nanometer-scale liposomes using a continuous-flow microfluidic system. Liposome size and size dispersion are determined using tandem
Wing Tsang, William S. McGivern, Jeffrey A. Manion
The thermal cracking patterns from the decomposition and isomerization of octyl-1 radicals have been determined from the pyrolysis of n-octyl iodide in single pulse shock tube experiments at temperatures in the 850-1000 K range and pressures near 2 bar
We used a cross capacitor to measure the relative dielectric permittivity ε r of O 2 at 273 K, 293 K, and 323 K and at pressures up to 6.5 MPa. Simultaneously we measured oxygen's complex refractive index n using a quasi-spherical cavity resonator at
In the uncertainty budget of Rockwell hardness tests, microform geometric errors of the diamond indenter are a major contributor. The microform calibration of Rockwell diamond indenters has been one of the key steps for Rockwell hardness standardization
JiYoung Chu, Quandou (. Wang, John P. Lehan, Ulf Griesmann, Guangjun Gao
In characterizing the performance of a phase-shifting interferometer, the dependence of the measured height on the spatial frequency is rarely considered. We describe a test mirror with a special height relief that can be used to measure the height
A new self-excited micro-oscillator is proposed as a velocity reference that could aid the dissemination of nanonewton-level forces that are traceable to the International System of Units (SI). An analog control system is developed to keep the actuation
This document describes NIST's high pressure natural gas flow calibration service (NGFCS). Flow calibrations are conducted offsite at the Colorado Experimental Engineering Station Incorporated (CEESI) in Garner, Iowa. A parallel array of nine turbine meter