Definitive measurement

Moody JR, and Epstein MS (1991) Definitive measurement methods. Spectrochim Acta 468 1571-... 

Test plans should include definite, measurable acceptance criteria, in addition to the amount of testing to be done. The test plan should include the data sets to be used and the detailed instructions for testing. Errors encountered during testing must be documented, including how they were discovered, their description, and any action taken to remedy the error. Errors must be remedied prior to the release of the software or computer system. Test results must be documented clearly to allow for pass/fail determinations to be made. 

Definitive measurements by fundamental quantities complemented by an empirical factor, e.g. titre (titrimetry), as well as by well-known empirical (transferable) constants like molar absorption coefficient (spectrophotometry), Nernst factor (potentiometry, ISE), and conductivity at definite dilution (conductometry)... 

In analytical practice, some methods using definitive measurements, in principle, are also caUbrated in an experimental way (e.g. spectrophotometry, polarography) to provide reliable estimates of S. 

Depending on the type of relationships between the measured quantity and the measurand (analytical quantity) it can be distinguished (Danzer and Currie [1998]) between calibrations based on absolute measurements (one calibration is valid for all1 on the basis of the simple proportion y = b x, where the sensitivity factor b is a fundamental quantity see Sect. 2.4 Hula-nicki [1995] IUPAC Orange Book [1997, 2000]), definitive measurements (b is given either by a fundamental quantity complemented by an empirical factor or a well-known empirical (transferable) constant like molar absorption coefficient and Nernst factor), and experimental calibration. 

On the basis of their origin, errors may usually be classified as determinate or indeterminate. The first are those having a value which is (in principle at least) measurable and for which a correction may be made. The second fluctuate in a random manner and do not have a definite measurable value. 

In dilute solution, the dependance of LnRj on solvent polarity for copolymers is definitely measurable, but it is significantly reduced with respect to that of the model compounds, by a factor of about 3 for a predominantly syndiotactic chain bearing keto-2-picolyl functions in the form of isolated units (DSm = 0.129,... 

Hales, J. M., and D. S. Renne, Source-Receptor Linearity Definitions, Measurement, and Practical Implications, Atmos. Environ., 26A, 2111-2123 (1992). 

Konstandopoulos, A. G. Flow resistance descriptors for diesel particulate filters Definitions, measurements and testing. SAE Technical Paper No. 2003-01-0846 (SP-1755) (2003). 

The remarkable variations in the viscosity of molten sulphur have already been mentioned. Definite measurements have been made at a series of temperatures by the method of rotating cylinders,5 and it, has been found that exposure of the liquid to air, especially below 160° C., has a marked effect on the viscosity from 160° C. onwards. The viscosity of purified (twice distilled but not gas-free) sulphur lias a value at 123° C. of 0 1094 C.G.S. units this falls to a minimum of 0 0709 at 150° C., rises gradually up to about 159° then rapidly increases above this temperature an exact transition point is not observed, however. The maximum for purified unexposed (gas-frcc) sulphur occurs at about 200° C. and has a value of 215 C.G.S. units. For purified (not gas-free) sulphur after prolonged exposure to the air, the maximum occurs at about 190° C, and may have a value as high as 800 C.G.S. units. Such high viscosity appears to be due to impurities, the chief being sulphuric acid, resulting from exposure to the air sulphur dioxide and ammonia in solution also have an appreciable effect. 

Definition For thermodynamic purposes, a property of the system is the reproducible resultb of a definite measurement on the system, verifiable by an independent observer0 and capable of changed... 

The coronene analysis also represented the first definite measurements of variable carbon-carbon bond lengths for any condensed ring aromatic hydrocarbon. Earlier indications of this effect had, however, been found in naphthalene and anthracene by Pauling et al. (1935) from an examination of Robertson s (1933a) publications on these molecules. 

Turpin, B.J., S.-P. Liu, P.H. McMurry, and S.J. Eisenriech. 1999. Definitive measurement of semivol-atilve PAHs with a diffusion separator Design and investigation of sampling artifacts in filter-adsorbent samplers. In Lane, D.A., Ed., Gas and Particle Measurements of Atmospheric Organic Compounds. Gordon and Breach Science Publishers, Amsterdam, pp.369-392. ... 

Key words Traceability Mole Definition Measurements Chemical metrology Calibration Validation Reference materials... 

In view of these issues, we have over several years undertaken a substantial research programme to develop definitive methods appropriate for in-house certification of matrix RMs, particularly for analytes at trace levels. These definitive measurement methods, most of which use isotope dilution mass spectrometry (IDMS), been the subject of extensive validation, including CCQM key comparisons and pilot studies involving other national measurement institutes. Hence, we are now able to augment interlaboratory data with data obtained at LGC using these very accurate measurements. We have also... 

Rowland, et al. (14) have used radiochemical tracer techniques to study reaction (1) and obtain equal yields of CO and COS. CS oxidation could account for a significant fraction of the atmospheric COS budget ( ) and definitive measurements of the mechanism of reaction (2), its primary products and the routes to, and yields of the ultimate stable products are needed. 

The future trends in XAFS spectroscopy relevant to characterization of catalysts in reactive atmospheres will thus be a combination of gm-ns time-resolved XAFS spectroscopy, time-resolved and spatially resolved XAFS spectroscopy, and state-resolved XAFS observations of the local structures of working catalysts. These more precise and definitive measurements, when coupled with advances in theory, will lead to more reliable structural analysis of catalysts and the ability to definitively resolve the structures in mixed-phase catalysts. It is indeed an exciting and continuously evolving field. 

The best operator which fits both minimization and localization schemes is, of course, the electron repulsion 1 /r12-In this manner as optimal energy gives a minimal non-definite measure between orbitals belonging to different shells, localization provides a maximal distance between orbitals belonging to the same shell. 

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