Error, casual

At X-ray fluorescence analysis (XRF) of samples of the limited weight is perspective to prepare for specimens as polymeric films on a basis of methylcellulose [1]. By the example of definition of heavy metals in film specimens have studied dependence of intensity of X-ray radiation from their chemical compound, surface density (P ) and the size (D) particles of the powder introduced to polymer. Have theoretically established, that the basic source of an error of results XRF is dependence of intensity (F) analytical lines of determined elements from a specimen. Thus the best account of variations P provides a method of the internal standard at change P from 2 up to 6 mg/sm the coefficient of variation describing an error of definition Mo, Zn, Cu, Co, Fe and Mn in a method of the direct external standard, reaches 40 %, and at use of a method of the internal standard (an element of comparison Ga) value does not exceed 2,2 %. Experiment within the limits of a casual error (V changes from 2,9 up to 7,4 %) has confirmed theoretical conclusions. 

This incident shows the weakness of checking procedures. The first operator may assume that if anything is wrong the checker will pick it up the checker may become casual because he has never known the first operator to make an error (see Sections 3.2.7 b and 14.5 c). 

We chose the number of PCs in the PCR calibration model rather casually. It is, however, one of the most consequential decisions to be made during modelling. One should take great care not to overfit, i.e. using too many PCs. When all PCs are used one can fit exactly all measured X-contents in the calibration set. Perfect as it may look, it is disastrous for future prediction. All random errors in the calibration set and all interfering phenomena have been described exactly for the calibration set and have become part of the predictive model. However, all one needs is a description of the systematic variation in the calibration data, not the... 

The settings on these programs may be changed to check for only those elements that you specify check for specific styles of writing, such as formal, standard, casual, and technical and check for errors as you type, or when you are finished. 

Tin (kassiteros) is mentioned casually by Dioscorides, as used for covering vessels of copper, and as one of the substances which may be used fo r vessels to contain mercury without being attacked, a curious error. 

In this work, we will not repeat the extensive discussions dedicated to these graphical representations that appeared in earlier reviews [49, 53]. We only wish to emphasize that the casual and the systematic errors inherent in a graphical analysis procedure are often underestimated. 

The third of the three adjacent peaks (29.207 minutes) is readily identified as 2-hydroxybenzaldehyde (salicylaldehyde) by comparison of the MS or IR spectrum with library data. It should be noted that the automated search routine in the MS software picked 3-and 4-hydroxybenzaldehyde as better matches than the 2-hydroxy compound, even though the 76 ion in the spectrum of the unknown is present only in the mass spectrum of the 2-hydroxy compound. However, the IR search routine correctly identified the 2-isomer. This illustrates that casual operators who rely on automated search routines for compound identification are much less likely to make errors when they have access to both IR and MS searching. 

Documenting software errors is important and problems should not be casually reported for repair by the programmer on an ad hoc basis. Problems found during testing are tracked using the HP internal defect control system (DCS). 

The objectives of thorough documentation are to define the manufacturer s system of information and control, to minimise the risk of misinterpretation and error inherent in oral or casually written communication, to provide unambiguous procedures to be followed, to provide confirmation of performance, to allow calculations to be checked and to allow tracing of a batch history. 

All sources of error can be divided into systematic and casual. The instrumental polarization (IP) of a telesc ope-polarimeter system is of the first type. It is stipulated, mainly, by that fact that the polarization degree of the light (both reflected and transmitted) varies with incident angle on the optical elements. In astronomical observations such surfaces are the telescopic mirrors, monochromator mirror, diffraction grating, filters, polarizers, SPSP etc. Therefore, even unpolarized light that falls on the main telescope mirror becomes partially elliptically polarized. The contribution of the polarization attributable to the instrument (see [2], for example) is Pj, (pj Qj, Uj and Vj. 

Also notice in Figure 5.30 that the AB spectra with AvU equal to 3, 6, and 15 all appear roughly first order, but the doublets observed in the range riv/J = 3 to 6 have chemical shifts that do not correspond to the center of the doublet (see Fig. 5.31). Unless the worker recognizes the possibility of second-order effects and does a mathematical extraction of the chemical shifts, the chemical shift values will be in error. Spectra that appear to be first order, but actually are not, are called deceptively simple spectra. The pattern appears to the casual observer to be first order and capable of being explained by the + 1 Rule. However, there may be second-order lines that are either too weak or too closely spaced to observe, and there may be other subtle changes. 

Accident Risk Factor A dangerous element of a system, event, process, or activity including casual factors such as design or programming deficiency, component malfunction, human error or environment, which can propagate a hazard into an accident if adequate controls are not effectively applied (MIL-STD-1574). 

In any study in the area of natural products chemistry, isolation and purification are the mandatory first steps that one encounters and must accomplish. Unfortunately, however, this phase is often handled too casually and without the realization that success or failure of a project is often solely determined by this step. Perhaps this attitude reflects the days when we were dealing with much larger quantities of static compounds that could be isolated readily by extraction with organic solvents and recrystallization. Or perhaps it is because most chemists, excepting professional isolation chemists or chromatographers, regard purification as a trial and error art that lacks logic or innovation. 

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