NIST National Institute

NIST, National Institute for Science and Technology (formerly the National Bureau of Standards, U.S.). t A.P.I. is the American Petroleum Institute. 

Because variations in accurate isotope ratio measurements typically concern only a few parts per 1000 by mass and there are no universal absolute ratios, it is necessary to define some standards. For this purpose, samples of standard substances are produced and made available at two major centers IAEA (International Atomic Energy Authority, U.K.) and NIST (National Institute for Standards and Technology, U.S.). Standards from other sources are also available. These primary standards can be used as such, or alternative standards can be employed if the primary ones are not available. However, any alternative standards need to be related accurately to the primary ones (see formulae below). For example, the material PDB (PeeDee belemnite), used particularly as a standard for the ratio of isotopes, is no longer readily available, and a new standard, VPDB,... 

NIST - National Institute of Standards and Technology, Gaithersburg, MD 20899. 

CONTAM96 is based on earlier programs by NIST (National Institute ol Standards and Technology), AIRNET (airflows), CONTAM (contaminant dispersal), and ASCOS (smoke transport). ... 

NIST. National Institute of Standards Technology (previously the National Bureau of Standards). 

The blue book compilations [154-158] are probably the most comprehensive sources of ionization constants collected from the literature (up to the end of 1970s). These are recommended for experts in the field. On the other hand, the red books contain critically selected values [159]. The six-volume set has been put into electronic form in cooperation with NIST (National Institute of Standards and Technology), and is available at a very reasonable price [160]. A two-volume set of critically determined constants is available from Sirius Analytical Instalments Ltd., and covers molecules of particular interest to the pharmaceutical community [161,162]. In Section 3.8 at the end of this chapter, a list of gold standard pKa values of mostly drug-like molecules is presented (see Table 3.1), with many of the values determined by the author since the early 1970s. 

In 1972, the National Bureau of Standard (now NIST, National Institute of Standard and Technology) started producing and selling two fixed point devices based on the normalsuperconducting transition of some metals ... 

Producers USGS = United States Geological Survey GSJ = Geological Survey of Japan NIST= National Institute of Standards and Technology (USA) ANRT = Association Nationale de la Recherche Technique (France)... 

NIST National Institute of Standards and PRM pattern recognition method... 

Now NIST, National Institute of Science and Technology. fThe bulk analysis is by standard wet chemical methods. The glassy phase was analysed by analytical transmission electron microscopy. Adapted from Qian Glasser (1988) and Qian et al. (1988). 

One problem is the availability of reliable reference materials for isotope ratio measurements. Certified isotope standard reference materials are available from NIST (National Institute of Standard Reference Materials, http //www.nist.gov/srd/, formerly NBS - National Bureau of Standards) and IRMM (Institute for Reference Materials and Measurements, http //www.irmm.jrc.de). There are isotope standard reference materials for light elements (H, Li, , C, N, O), Mg (magnesium metal isotopic standard NIST SRM 980), and for moderately heavy elements such as (potassium chloride isotopic standard NIST SRM 985), Cr (chromium metal isotopic standard NIST... 

Calibrated periodically or prior to use to master standards traceable to the NIST (National Institute for Standards and Technology)... 

Table 2 Comparison of Cholesterol Reference Method Laborato- tute, NIST National Institute of Standards and Technology (US ry Network (CRMLN) traceability model to the International Or- NMI), IDMS isotope dilution mass spectrometry, ACL accredited ganization for Standardization (ISO) model. BIPM International calibration laboratory, AK Abell-Kendall Bureau of Weights and Measures, NMI National Metrology Insti-...

All reagents must be of recognized analytical grade. The water used for dilution should be deionized and filtered. The water should have a resistance of >10 MD/cm and not contain particles >0.20 pm. The bottles that are to contain sample, calibration standards, and reagent solutions should be made of polyethylene or polypropylene. For the anions, borosilicate glass may also be used. Stock standard solutions may be purchased as certified solutions from different manufacturers or NIST (National Institute for Standards and Technology, USA), or else prepared from salts or oxide that are dried, dissolved, and diluted. 

Most of the instrumental direct methods, which are employed in routine analyses, are highly matrix-dependent, therefore methods must be validated with certified standard reference materials. Standard plant reference materials (SRMs), with certified elemental contents can be obtained from NIST, National Institute of Standards and Technology of the United States Department of Commerce or from BCR, Community Bureau of Reference, Commission of the European Community (Colinet et al., 1982 Criepink, 1990 Horwitz and Albert, 1991). 

Chapter 6 Smoke test. The test is based on the National Bureau of Standards (NBS, now NIST, National Institute of Standards and Technology) smoke density chamber, which has also been standardized as ASTM E 66239 (see also Section 4.1.1). The test exposes a vertical test specimen ca. 75 mm x 75 mm (3 in. x 3 in.) to an incident radiant heat flux of 25kW/m2, from a radiant heat burner for 4 min, in the presence of an open-flame pilot burner. The test applies to the same materials as the heat release rate test. The acceptance criterion is an average maximum specific optical density of smoke that does not exceed 200 (no units). 

The on-site version of AMDIS is a 16-bit Windows application running under OS2 operating system of the Dolch PC. This version of AMDIS was specially designed by NIST (National Institutes of Standards and Technology) for OPCW on-site analysis use. Its role in the postprocessing of analysis data is equivalent to the role of the blinded mode software in regard to the general control of the instrument and the acquisition of the data restrict the information on the identity of chemicals present in the sample to chemicals that are only relevant to the inspection aim. 

For very accurate manometer readings, the NIST (National Institute of Standards and Testing) has a compiled list of eight possible errors that can develop while reading manometers. These errors introduce extremely small variations and therefore are not included here. If you need to read a manometer to the sensi-... 

NIST National Institute of Standards and Technology U.S. Department of Commerce Publications and Programs Inquiries Room El28, Administration Building Gaithersburg, MD 20899 (301)975-3058 http //www.nist.gov/ ASTM American Society for Testing and Materials 100 Barr Harbor Dr. West Conshocken, PA 19428-2959 (610) 832-9585 http //www.astm.org/... 

BCR = Commission of the European Communities, Community Bureau of Reference, Belgium. IAEA = International Atomic Energy Agency, Austria. NIES = National Institute of Environmental Science, Japan. ISS = Istituto Superiore di Sanita (National Institute of Health), Italy. NIST = National Institute of Standards and Technology, USA. AGAL = Australian Government Analytical Laboratory, Australia. NRCC = National Research Council of Canada, Canada. 

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