Unreliable data

It has become an accepted wisdom that the use of RMs or CRMs will help to improve the accuracy and precision of an analytical process. This belief has led to a rapid growth in the use of RMs and CRMs in commercial laboratories. The authors and many analysts the world over support this view, but also recognize that in far too many cases inexperience and carelessness conspire together with the result that error accumulates and often unreliable data are produced. 

We need the compilation of much large databases, and vetting to eliminate the unreliable data, and to publish databases with more substances with more properties. 

No amount of elegant statistics or chemometric procedures will rescue inadequate or unreliable data. 

The water forces thefat/oil into the cyclohexane and the excess iodine monochloride moves into the water, where it is converted to I2 and can be titrated with the water-soluble sodium thiosulfate. Potassium iodide solution acts to convert the excess iodine monochloride to free iodine (blue) which can be titrated to a colorless end point with sodium thiosulfate. Soluble starch aids in being able to see the free iodine and getting a repeatable end point. The normality of the sodium thiosulfate solution used is generally ft 1N however, this may change depending on the level of iodine monochloride that is to be titrated. Ideally any titration should use between 5 and 50 ml (1 buret volume) of solution—titrations outside of this range can produce unreliable data. 

If there are significant technical deficiencies with an independent measure (e.g. no consensus for participant results) then unreliable data are excluded when setting the assigned value. 

Dealing with missing, semi-quantitative and unreliable data 101... 

Because of the close admixture with other phases, which is often on a scale of lOpm or less. X-ray microanalysis of the aluminate phase in clinkers is frequently difficult or unreliable. Data have been reported for cubic, orthorhombic, pseudotetragonal or unspecified forms of the aluminate phases in ordinary clinkers (R1,K1,B2,H3) and for aluminate phase (G3,G4,S1,B3) and glass (B3) in white cement clinkers. Tables 1.2 and 1.3 include, respectively, average compositions based on these somewhat scanty data, and suggested site occupancies based on them. The values in both tables take into account both the experimental data and the requirement of reasonable site occupancies. 

Even if the standard deviation is given in each case, it may still be illustrative to calculate a few partition coefficients based on these equations. The result is shown in Table 6.9. The agreement is good, but not excellent, although when experimental values of, for example, benzene in SDS vary between 400 and 1410 (Abraham et al. used 890 as input), it is not easy to evaluate whether the larger discrepancies are due to the model equation or to unreliable data, or simply, the problem concerning data presented in the literature is the lack of a standard state. 

Identified by Prescott et al. (1937a,b) through a naphthyl carbamate derivative and by Lockhart (1957). Rhoades (1960) with GC/MS measures a concentration of 0.2-4.0 ppm in green and 0.6-4 ppm in roasted beans (given also as unreliable data). It constitutes only 0.4 % of the coffee aroma according to Merritt et al. (1963) and is one of the alcohols found by Merritt and Robertson (1966) in the analysis of the total... 

It is clear from both interlaboratory studies that differences in measurement data on SCCPs (and likely CPs of other chain length) can be notable. The choice of quantitative procedures used by laboratories and also choice of external standard employed (this was certainly the case in the Tomy et al. (1999) smdy [62]) can contribute to unreliable data. The recent commercial availability of impurity-fi ee synthetic C10-C13 solutions should eliminate the uncertainty in preparation of working standard solutions. However, other confounding variables like choice of extraction and clean-up procedures have not been quantitatively assessed and are likely to contribute to the uncertainty in CP data. 

Only limited - and somewhat unreliable -data are available on the effects of human exposure to molybdenum. The population of Ankavan (Armenia Republic) takes in between two- and 10-fold more molybdenum via local foodstuffs (10-15 mg Mo per day) than people in areas with a normal molybdenum supply (Kovalskij... 

Despite the conflicting and sometimes unreliable data, one conclusion appears inescapable—on many occasions the addition of sulfur to asphalt has produced materials with improved strengths and durability as proved in usage. Various organizations have prepared floors and road sections which demonstrate forcefully that beneficial results have been obtained even if they were not always reproducible. Unfortunately, little of this work is published. However, several papers (36, 37) do describe the benefits obtained under separate sets of conditions. Tables I-III present data which quantify some of these benefits. 

Good preparation alone is not sufficient to eliminate bottlenecks or unreliable data during the test. It is just as important to check and troubleshoot for bottlenecks and sources of unreliable data. The following considerations are important and are based on the author s experience supplemented by Refs. 2, 61, 133, 239, and 268. 

The construction of fault trees is by far not a trivial task, but requires a lot of expert knowledge and experience. The quantification of fault trees is for the time being extremely problematic, because the available databases for the determination of unreliability data of components and other probability data need significant further development. However, the existing databases and subjective estimated values may be used if two different plant designs are to be compared with each other, as the absolute values at the end of the calculation are not of interest but, instead, their relative comparison. 

A reputation for integrity is vital to the successful operation of the radioanalytical chemistry laboratory, as for any analytical facility. The client depends on the validity of the reported analytical results in operating a program or performing a task. In turn, the client provides information based on the analytical results to various stakeholders, including workers, the public, and regulators, to demonstrate safe operation or absence of excessive risk. Even a minor instance of unreliable data can call into question entire reports of results and thus, the operation of the client s program. 

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