United States National Institute of Standards and

United States Geological Survey National Water Quality Assessment (NAWQA) program, 26 33-34 U.S. HPV Challenge Program, 24 186 U.S. Metric Association, 15 768 United States National Institute of Standards and Technology (NIST) steam tables, 23 202 United States National Laboratories (USNL), 24 358... 

One of the most accurate clocks in the world is located at the United States National Institute of Standards and Technology (NIST) in Boulder, Colorado. This cesium fountain atomic clock provides the official time for the United States. The dock is based on the natural resonance frequency of the cesium atom (9,192,631,770 Hz.), which defines the second. 

National Institute of Standards and Technology (NIST). The NIST is the source of many of the standards used in chemical and physical analyses in the United States and throughout the world. The standards prepared and distributed by the NIST are used to caUbrate measurement systems and to provide a central basis for uniformity and accuracy of measurement. At present, over 1200 Standard Reference Materials (SRMs) are available and are described by the NIST (15). Included are many steels, nonferrous alloys, high purity metals, primary standards for use in volumetric analysis, microchemical standards, clinical laboratory standards, biological material certified for trace elements, environmental standards, trace element standards, ion-activity standards (for pH and ion-selective electrodes), freezing and melting point standards, colorimetry standards, optical standards, radioactivity standards, particle-size standards, and density standards. Certificates are issued with the standard reference materials showing values for the parameters that have been determined. 

Science cannot be performed without an accurate system of measurement, which is globally standardized and compulsory. Units and standards of measurement are agreed upon and harmonized on an international basis by the Bureau International des Poids et Mesures in Sevres, France, and by the International Organization for Standardization in Geneva, Switzerland. The units and standards are then laid down in national laws. Nearly all countries have accepted the Systeme International d Unites (SI units) as their system of measurement. This also applies to countries that had been accustomed to use British units like Australia, Canada, South Africa and the United States. In Britain, SI units are official from January 2010. The valid standards are available from the competent bureaus, for example Bureau International des Poids et Mesures, www.bip.fr National Measurement Institute (Australia), www.measurement.gov.au National Institute of Standards and Technology (NIST, USA), www.physics.nist.gov/ Pubs/SP811/... 

The cone calorimeter used in this study (5) is a somewhat enlarged version of the model used at the National Institute of Standards and Technology in the United States. This particular equipment takes samples of size 20 cm x 20 cm mounted in a horisontal position on top of a load cell. Above the sample there is a cone heater and a spark ignitor. Gas samples are taken in fan ventilated exhaust duct mounted above the cone heater. The radiation used has been 50 kW/m2 and free convection ventilation over the sample. 

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)... 

OfScial contribution of the National Institute of Standards and Technology not subject to copyright in the United States. Certain commercial materials and equipment are identified in order to specify adequately experimental procedures. In no case does such identification imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the items identified are necessarily the best available for the purpose. 

Standardization is a comparison with a standard of known and accepted value. Standards may be of several sources primary standards [prototype state-of-the-art standards found at NIST the National Institute of Standards and Technology (formerly known as the National Bureau of Standards (NBS), or national equivalent outside the United States] secondary, working standards (standards calibrated to primary standards, which are used for working tools and instruments) and in-house-developed or interim standards (standards developed and used by a particular facility when no primary standard is available). 

R. J. Brodd, Factors Affecting U. S. Production Decisions Why are There No Volume Lithium-Ion Battery Manufacturers in the United States ATP Working Paper Series, Working Paper 05-01, National Institute of Standards and Technology, Gaithersburg, June 2005. 

Finally, the National Institute of Standards and Technology (NIST) in the United States has several chemical kinetics databases that are available for purchase from the Office of Standard Reference Data at NIST. The NIST Standard Reference Data Base 17 gives gas-phase rate constants through 1993 and Data Base 40 gives solution-phase data through 1992. In addition, aqueous-phase data are available through the Radiation Chemistry Data Center of the Notre Dame Radiation Laboratory (http //www.rcdc.nd.edu/). 

During the same period, NIST (the National Institute of Standards and Technology, formerly the National Bureau of Standards) reported that the cost of nondiagnostic medical tests in the United States at the end of the 1990s was 36 billion, about one-third of the total cost of testing. Not all these tests are chemical, and so not all the retests would have been a result of poor quality in a laboratory, but the figure is very large (U.S. Senate 2001). 

Robert A. Beyerlein, National Institute of Standards and Technology Robert J. Bianchini, Colgate-Palmolive Company Christopher S. Brazel, University of Alabama Kimberly A. Brown, United States Army... 

A traceability structure based on the National Institute of Standards and Technology (NIST)-traceable reference materials produced by commercial suppliers under the supervision of NIST in the United States. 

In the United States, the National Institute of Standards and Technology (NIST) also has compiled a list of units outside the SI that it has approved for domestic use (see Table 5). It recommends defining them in terms of accepted SI units. The CIPM does not encourage the use of units on the NIST list but accepts all of them, excluding the curie, roentgen, rad,... 

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). 

For more than a decade, numerous research studies have been carried out on the flame-retardant properties conferred by nanoparticles and mainly by organo-modified layered silicates (OMLS). Earlier work at Cornell University and National Institute of Standards and Technology in the United States showed that nanocomposites containing OMLS reduced polymer flammability and enhanced the formation of carbonaceous residue (char).14 Owing to a strong increase in polymer viscosity, impairing processability, and also due to the breakdown of ultimate mechanical properties, the acceptable rate of incorporation for nanoparticles to improve flame retardancy is generally restricted to less than 10 wt %. 

Certified isotopic standards are available for some elements but by no means all. Such standards are available from the National Institute of Standards and Technology [52] and New Brunswick Laboratory [53] in the United States, and from the Institute for Reference Materials and Measurements [54] in Belgium. De Bievre et al. have published a review of reference materials available for isotope ratio measurements [55]. It is clearly desirable to use certified materials for instrument calibration if at all possible. If no standard is available for the element in question, the analyst has little choice but to obtain a pure sample of it and assume it has the composition listed by IUPAC [1]. A few elements, with lead being the outstanding example, have isotopic compositions that vary widely in... 

The National Institute of Standards and Technology (formally the National Bureau of Standards) represents the United States at the CGPM. They store the United States copies of the original measurement prototypes. 

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