Checking Results

In many cases, some property of the output of the simulation is described by a known analytical or empirically derived expression which can be used to test if the simulation output is correct. The peak current of a cyclic voltammogram is the largest current recorded on the forward sweep. For an electrode process with fully reversible electrode kinetics, the peak current of a voltammogram in amps (A) is given by the Randles-Sevcfk equation [7-9] for a one-electron reversible reduction process  

In this figure we have arbitrarily specified an accuracy tolerance of 0.1% (well below the typical threshold of experimental accuracy), though ultimately it is up to the simulation user to judge what constitutes an acceptable level of accuracy. Any pair of values (AX, A ) inside the shaded 

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As you near completion of each PSM element s modification or redesign, it s useful to check results against the criteria you established as part of developing your plan. You may find it helpful to review the plan at intervals, and to revisit Section 3.2, which discusses PSM criteria. Similarly, you will want to assure that the modifications you devise address the priorities you identified as part of the planning process (see Section 5.3). 

Bostelmann N (2000), An Examination of the Influence of Marketing Organisations on Animal Health and Meat Quality of Fattening Pigs on the Basis of Collected Slaughter Check Results, pH-values and Meat Temperatures of the Ham, Dissertation, University Berlin. 

Different reaction conditions were checked. Result with the highest ee is given here (in CH2CI2, O C, mole ratio ligand Et2Zn ketone 1 0.95 0.9). 

Calibration procedures] are established and maintained to include details of equipment type, identification number, location, frequency of checks, check method, acceptance criteria, and the action to be taken when check results are unsatisfactory. Calibration records are maintained, and calibration environmental conditions are controlled. 

In Steps 1 through 6 the chemist has evaluated batch QC check results and came to a conclusion on the acceptability of the whole batch. In Step 6 the chemist focuses on individual sample QC checks and on remaining qualitative and quantitative aspects of analysis. The chemist reviews the data for each individual sample in order to evaluate the following issues ... 

All experimental data obtained by AAS are incorrect, to some extent. This is mostly hidden by measurement uncertainty, which can be calculated and quantified. In contrast to measurement uncertainty, there are uncertain measurements, or analytical errors, which cannot be estimated since the error is largely unknown. How can one know whether an analytical error has occurred Normally one does not know, which is the inherent problem with errors This is why a healthy dose of suspicion is never out of place. If a single result, or a series of results, seem unusual, that is, deviating from the expected values, this may well be very important or just a blunder. In both cases, the experimental data need to be checked. This can be done in different ways and is quite simple (obvious controls, such as calibrants and dilutions, are not discussed here). The suspected sample solution can be diluted (e.g., 1 + 1 and 1+3) and reanalyzed. If these results (after taking into account the dilution factor) remain at the level of the first result, there is probably no error. Another way of checking results is to reanalyze the sample at other wavelengths that are sufficiently sensitive, for example, for Pb, 283.3 and... 

All-electron Dirac-Fock procedures are also capable of producing accurate molecular wave functions (76). However, it is not feasible at present to use this method as a standard tool for heavy-element systems because of the computational constraints. This approach can result in calculations of questionable value due to the use of inadequate basis sets and modest levels of Cl. Such calculations may not only be inaccurate, but, can be misleading if used for comparisons with REP calculations. Carefully selected benchmark calculations would be extremely useful for checking results of REP-based studies. 

The development and standardization of reliable test procedures requires an ample supply of well-characterized reference materials. These samples are used for round-robin tests by participating laboratories in the method development. A reliable set of reference materials are available from the National Bureau of Standards. These special reference materials are described by Haines in this symposium series. The Bureau has packaged the materials in an appropriate size and secure container. Producer and user laboratories have these reference materials available to cross-check results and resolve differences in specification analyses. These reference standards are available at a reasonable cost. 

A number of methods for measuring the thickness of oxide films formed on metals have been described by Kubaschewski and Hopkins (1). Bach method has its special advantages and limitations and it is highly important, wherever possible, to check results obtained by one method with those made by one or more of the other methods. 

Which analytical methods shall be used with spec-checked results for this product. 

Useful in soils with fines, uniform compaction, easy to check results, slow... 

Therefore if the difference between duplicated results measured under repeatability conditions is greater than 2.8crr there should be concern that there is something wrong with the analysis. This can be used as part of a quality control procedure to ensure consistency of results. An equivalent difference can be defined for a reproducibility standard deviation (maximum permissible difference 2.8 x oy is known as the repeatability limit (r) and 2.8 x [Pg.65]

A true PPC requires sampling from the posterior distribution of the fixed and random effects in the model, which is typically not known. A complete solution then usually requires Markov Chain Monte Carlo simulation, which is not easy to implement. Luckily for the analyst, Yano, Sheiner, and Beal (2001) showed that complete implementation of the algorithm does not appear to be necessary since fixing the values of the model parameters to their final values obtained using maximum likelihood resulted in PPC distributions that were as good as the full-blown Bayesian PPC distributions. In other words, using a predictive check resulted in distributions that were similar to PPC distributions. Unfortunately they also showed that the PPC is very conservative and not very powerful at detecting model misspecification. 

Hence, proceeding from the above considerations it is possible to introduce the following problem to attempt to predict a certain experimentally checked result which would be difficult to explain from the standpoint of other concepts or, to put it simply, it would be virtually impossible. This test would evidently be a very rigorous verification of the entire ideological basis of the proposed approach. 

The cross-check results obtained on both procedures suggest that either the CRA-63 or HGA-70 procedure will provide reliable and accurate analysis of petroleum for trace levels of beryllium and there should be no significant difficulties in establishing these methods in other laboratories. 

From March 1960 to February 1961, a press with a single pack identical to those on the FSG plant was available at the SACSIR laboratories at Pretoria to check results obtained on the FSG plant, and to try out improvements in the design of pack components and methods of operation (10, II). The unit was also used to test, under carefully controlled conditions, packs sent from the FSG plant. The only difference between operation on the units at Pretoria and at the FSG plant was that the former was fed with synthetic brackish water from which the clay particles found in the FSG raw water were absent. 

The low cross-section of the reaction of I(n,p) I with fast neutrons (cf Table 2.3) and a low abundance of neutrons with energies higher than 9MeV, which are needed for this reaction, in the neutron spectrum of a nuclear reactor result in a detection limit which is not sufficient for iodine determination in most types of foodstuffs, even if an RNAA procedure is applied. However, this reaction, which is completely independent in relation to the reaction of I(n, ) I with thermal and epithermal neutrons may be useful for cross-checking results in analysis of foodstuff samples with higher iodine contents, using the so-called self-verification principle in NAA (Byrne and Kucera, 1997). Detection limits of various NAA modes, which were achieved in the authors laboratory are compared in Table 2.4. 

A TV video camera in conjunction with a TV monitor and video cassette recorder (Figure 1) has an enormous advantage over the conventional 35 mm photography. Firstly, since an entire experiment can be stored on a TV cassette and thus becomes part of a permanent Phycomyces library, we can rerun any given experiment, many lasting several hours, at any future date. Secondly, the reliability of measurements is enhanced since replicates may be taken and the taped experiment may be stopped or rewound to check results. 

The quality control (QC) tests discussed in Sections 10.5 and 11.2.9 are integral parts of QA designed to check results. Some QC measures are prompt indicators that warn of problem occurrence at the time of analysis others are delayed indicators that require backtracking to And when a problem first arose. Control charts for radiation detector operation are an example of a prompt indicator of reliability. Records of deviations from the norm in an analysis or a measurement may also be prompt indicators if immediately considered. Periodic blank, blind, and replicate analyses, especially interlaboratory comparisons, are delayed indicators for which results may not be available for days or weeks after a problem has arisen. Review and assessment of compiled data are delayed indicators of information quality. 

However, it is evident that the presence of calcium ions is not the only factor to be considered in this sort of phenomenon. Thrombin, like all the other enzymes, is very sensitive to the physical and chemical condition of the medium, and if we expect to obtain check results by mixing serum with distilled water, it is much to be feared that we shall obtain irregular and even contradictory results if instead of distilled water we take another serum, especially an old serum, since the chemical composition... 

Further, primary current distributions are compared with analytic solutions and some other calculated examples are discussed. To check results of secondary distributions, a copper electrorefining cell was built and quantitative data were obtained. 

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