Primary errors

As with most instruments, erroneous results may be obtained if the high resolution diffractometer is not correctly set up. In modem instmments this is greatly assisted by the manufacturers, by prealigned components, permanent alignment on installation and by automated algorithms for specimen alignment. The primary errors to be considered are... 

The contributions to the microsolvent KIE from various classes of mode are illustrated in Table 1-1. These factors indicate that the primary error in the original study was to miss the effect of about 10% in the high frequency modes, with a... 

Typical sources of error in coulometric titrations are variation in the current during electrolysis and errors in measurement of current and time. Departure of the process from 100% current efficiency is the primary error source. In some cases, the equivalence point is not the endpoint of the titration. 

These various sources of error make it difficult to obtain satisfactory raw rates of reaction. There is no way of eliminating all error in the X, r, T readings from conventional reactors. As a result, the rates of reaction obtained by taking discrete differentials of raw conversion data with space time (in the case of the PFR and die BR) are subject not only to the primary error in experimental readings of X and r, but also to the ampli-... 

I-cell disease is, then, a disorder of targeting, which appears to arise during the synthesis of the acid hydrolases. The detailed enzymology of the primary error is not yet fully understood. 

Human error is the incorrect or wrong execution of a required human action that is, it is a human failure. Human error and mistakes typically result from the frailties of the human nature. Human errors can easily cause hazards and place people, equipment, and systems at risk. Human error is an act that through ignorance, deficiency, or accident departs from or fails to achieve what should be done. Errors can be predictable and random. Errors can also be categorized as primary or contributory. Primary errors are those committed by personnel immediately and are directly involved with an accident. Contributory errors result from actions on the part of personnel whose duties preceded and affected the situation during which the results of the error became apparent. 

Reason s error types can be related to the stages in the cognitive process at which thty occur. For the cognitive stages of planning, storage and execution the primary error types are mistakes, l >ses and sUps respectivety. 

The easiest way to extract a set of objects from the basic dataset, in order to compile a test set, is to do so randomly. This means that one selects a certain number of compounds from the initial (primary) dataset without considering the nature of these compounds. As mentioned above, this approach can lead to errors. 

Should there be more than one known material, a weighted average of the individual differences (x) should be taken. The value of 5- should be based on the combined estimate from the two or more materials (perhaps different primary standards for bases). Should the materials differ markedly in composition, a plot of the individual constant errors against composition should be made. If the constant error appear to depend upon the composition, they should not be pooled in a weighted average. 

Under these conditions some OH is consumed in neutralizing CO2. The result is a determinate error in the titrant s concentration. If the titrant is used to analyze an analyte that has the same end point pH as the primary standard used during standardization, the determinate errors in the standardization and the analysis cancel, and accurate results may still be obtained. 

Chemical analysis of the metal can serve various purposes. For the determination of the metal-alloy composition, a variety of techniques has been used. In the past, wet-chemical analysis was often employed, but the significant size of the sample needed was a primary drawback. Nondestmctive, energy-dispersive x-ray fluorescence spectrometry is often used when no high precision is needed. However, this technique only allows a surface analysis, and significant surface phenomena such as preferential enrichments and depletions, which often occur in objects having a burial history, can cause serious errors. For more precise quantitative analyses samples have to be removed from below the surface to be analyzed by means of atomic absorption (82), spectrographic techniques (78,83), etc. 

Projections of market penetrations and contributions to primary consumption of energy from biomass are subject to much criticism and contain significant errors. However, even though these projections may be incorrect, they are necessary to assess the future role and impact of renewable energy resources, and to help in deciding whether a potential renewable energy resource should be developed. 

A main reason for mnning an experiment in blocks is to ensure that the effect of a background variable does not contaminate evaluation of the effects of the primary variables. However, blocking removes the effect of the blocked variables from the experimental error as well, thus allowing more... 

Randomization means that the sequence of preparing experimental units, assigning treatments, miming tests, taking measurements, and so forth, is randomly deterrnined, based, for example, on numbers selected from a random number table. The total effect of the uncontrolled variables is thus lumped together into experimental error as unaccounted variabiUty. The more influential the effect of such uncontrolled variables, the larger the resulting experimental error, and the more imprecise the evaluations of the effects of the primary variables. Sometimes, when the uncontrolled variables can be measured, their effect can be removed from experimental error statistically. 

Feedforward Control If the process exhibits slow dynamic response and disturbances are frequent, then the apphcation of feedforward control may be advantageous. Feedforward (FF) control differs from feedback (FB) control in that the primary disturbance or load (L) is measured via a sensor and the manipulated variable (m) is adjusted so that deviations in the controlled variable from the set point are minimized or eliminated (see Fig. 8-29). By taking control action based on measured disturbances rather than controlled variable error, the controller can reject disturbances before they affec t the controlled variable c. In order to determine the appropriate settings for the manipulated variable, one must develop mathematical models that relate ... 

The primary assumption in reconciliation is that the measurements are subject only to random errors. This is rarely the case. Misplaced sensors, poor sampling methodology, miscalibrations, and the like add systematic error to the measurements. If the systematic errors in the... 

Currenl (ratio) error at % of rated primary current... 

These errors are valid only when the CTs are loaded by a minimum 25% of the rated VA burden, for CTs of class 1 and 50% for CTs of classes 3 and 5 and a primary currenl of not less than 5% or more than 120% of the rated current. The measuring CTs may not transform correcllv unless the above conditions are met. 

Accuracy Current error at Phase displacement Composite error class rated primary angle S (Figure at rated... 

Any main CT that is itndeiioaded will also add to the error in the measurement. Similarly, if provision is tnade in the primary of the summation CT to accommodate fntnre circuits but is not being utilized it tnust be left open, otherwise it will also add to the error. The impedance of the shorting terminals will add to the impedance of the circuit and will increase the total error. 

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