Journal of Research of the National Institute of Standards and Technology articles from January 2005

Journal of Research of the National Institute of Standards and Technology archives from January 2005

Details of the 1998 watt balance experiment determining the Planck constant.
January 1, 2005... The National Institute of Standards and Technology (NIST) watt balance experiment completed a determination of Planck constant in 1998 with a relative standard uncertainty of 87 X [10.sup.-9] (k = 1), concurrently with an upper limit on the...

Re-analysis of the uncertainty of the 0.895 [micro]m diameter (NIST SRM[R] 1690) and the 0.269 [micro]m diameter (NIST SRM[R] 1691) sphere standards.
January 1, 2005... The uncertainties of the mean diameters of the nominal 1.0 [micro]m SRM[R] 1690 polystyrene spheres and of the nominal 0.3 [micro]m SRM[R] 1691 polystyrene spheres are recomputed using the current NIST Guidelines for computing uncertainty. The...

Slip correction measurements of certified PSL nanoparticles using a nanometer differential mobility analyzer (Nano-DMA) for Knudsen number from 0.5 to 83.
January 1, 2005... The slip correction factor has been investigated at reduced pressures and high Knudsen number using polystyrene latex (PSL) particles. Nano-differential mobility analyzers (NDMA) were used in determining the slip correction factor by measuring...

Measurement of workability of fresh concrete using a mixing truck.
January 1, 2005... The main objective of this study is to evaluate the workability of fresh portland cement concrete while it is still in the mixing truck by determining fundamental rheological parameters (plastic viscosity and yield stress). Nine concrete...

A survey of tables of probability distributions.
January 1, 2005... This article is a survey of the tables of probability distributions published about or after the publication in 1964 of the Handbook of Mathematical Functions, edited by Abramowitz and Stegun Key words: continuous univariate distributions;...