National Institute for Standards and

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,... 

Standard substances are available from such agencies as the International Atomic Energy Authority (U.K.) and the National Institute for Standards and Technology (U.S.). 

The melt flow rate of a polymer is the weight of polymer in grams that extrudes from a standard capillary die under a standard load, at a standard temperature, over a ten minute period. The term melt index is used exclusively for polyethylene melt flow rate is the preferred term for all other polymers, We measure melt flow rates using a piece of equipment called a melt indexer . The capillary dimensions, testing temperature, and load are specified for a given polymer by the National Institute for Standards and Testing. 

The National Bureau of Standards (NBS, now National Institute for Standards and Technology, NIST) fire and smoke transport model, F.A.S.T., version 18.3, was used to generate the information concerning the temperatures and gas concentrations. This is a zone model which predicts the formation of two layers in each compartment. 

Polymers Division, National Institute for Standards and Technology,... 

The author thanks the National Science Foundation, National Institutes of Health, the Petroleum Research Fund, and especially the National Institute for Standards and Technology for funding of the part of the research discussed here that was carried out in his research group. I am immensely grateful to my co-workers, including Dr. Gary Caldwell, Dr. Jeff... 

Lias, S. G. Liebman, J. L. Levin, R. D. Kafafi, S. A. Stein, S. E. NIST Positive Ion Energetics Data Base, Office of Standard Reference Data, National Institute for Standards and Technology Gaithersburg, MD, 1993 SRD Database 19A, Version 2.0. 

Because laboratory testing often applies to articles in international trade, international accreditation is often sought. There are many international accrediting agencies in existence. Two examples are the National Institute for Standards and Technology (NIST) and the American Association for Laboratory Accreditation (AALA). NIST administers what is called the National Voluntary Laboratory Accreditation Program (NVLAP). 

Stalynick, J.K. and Mighell, A.D., Crystal Data File, National Institute for Standards and Technology, Gaithersburg, MD (1982). 

Spectroscopy data Infrared (grating [8003]), nuelear magnetic resonance [943C] and mass spectral data have been reported (Lide Milne, 1996 Aldrieh Chemical Co., 1998 National Institute for Standards and Technology, 1998)... 

The ITS is an artifact scale, designed to relate temperature measurements made with practicable instruments as closely as possible to the thermodynamic scale. The scale is established and controlled by the International Committee of Weights and Measures (BIPM) through its Consultative Committee on Thermometry, which was established in 1937. The BIPM itself is established to maintain and implement the Treaty of the Meter, to which most nations of the wodd subscribe thus the ITS has not only scientific but legal status in most nations. Within nations, the Temperature Scale is maintained by national standards establishments, eg, in the United States the National Institute for Standards and Technology (NIST), in England the National Physical Laboratory (NPL), and in Germany the Physikalisch-Technische Bundesanstalt (PTB). 

Every organic chemical has a mass spectrum, which is a combination of ions with different masses and different intensities (abundances). To identify a compound, its mass spectrum is compared to the mass spectra of standards, analyzed under the same instrument settings, and to the EPA/National Institute for Standards and Technology (NIST) mass spectra library. The EPA/NIST library is stored in the database of the computer that operates the instrument. A comparison to the library spectra is possible only if there is consistency in the compound spectra generated by different GC/MS systems at hundreds of environmental laboratories. To achieve such consistency, the EPA methods for GC/MS analysis include the mass... 

Systems of classification very often follow the application fields, e.g. the catalogues of the Institute for Reference Materials and Measurements (IRMM), the National Institute for Standards and Technology (NIST), Laboratory of the Government Chemist (LGC), etc. or the database for certified reference materials COMAR. In all application fields like food and agriculture, environment, health and safety, industry and services, etc., reference materials are used for ... 

MagProp is a module in the Data Analysis and Visualization Environment (DAVE) from the U.S. National Institute for Standards and Technology (NIST) Center for Neutron Research. Cf. Azuah RT, Kneller LR, Qiu Y, Tregenna-Piggott PLW, Brown CM, Copley JRD, Dimeo RM. J Res Natl Inst Stand Technol 2009 114 341-58. 

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. 

Chang, S.S., Senich, G.A. and Smith, L.E. 1982, Migration of Low molecular weight Additives in Polyolefins and Copolymers, Final Report, NBS1R 82-2472, National Institute for Standards and Technology, Washington, DC. 

NIST. 1995. National Institute for Standards and Technology. Standard reference materials catalog, special publication 260. U.S. Department of Commerce, Washington, DC U.S. Government Printing Office. 

The Protein Data Bank (PDB) (27, 28) is now coordinated by a consortium of several institutions (Rutgers University, the San Diego Supercomputer Center, and National Institute for Standards and Technology). As of this writing, the PDB has over 18,000 structures. 

Lookup2.xls illustrates how to look up values in a two-way table. The data table used in this example is part of the Steam Tables and is reprinted from ASME International Steam Tables for Industrial Use. The information in the table was provided by the National Institute for Standards and Technology (NIST) and is in the public domain. 

A high-quality connector is then attached to the cable. The next step is to perform offset zeroing with fixed, P/o precision, low-temperature coefficient resistors, followed by NIST (National Institute for Standards and Technology) traceable calibration. 

In the case of the porosity measurements, in addition to the same cellulose samples, samples of oak and white pine were also examined. These samples of wood were ordinary commercial lumber samples (the same pine having been previously used in fire experiments at the Center for Fire Research of the National Institute for Standards and Technology). The pine had an initial dry density of 0.377 g/cc, and the oak 0.734 g/cc. Both of these wood samples were pyrolyzed for two hours at 1273 K, in helium, in order to prepare the chars for testing. The char yields were in the neighborhood of 28% by mass of the starting oak and 26% by mass of the starting pine. 

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