Precision criteria

Quality assurance (QA) is a generic term for all activities required to maintain quality in analytical results. These include laboratory management structures and sample documentation procedures, as well as the more practical sample preparation and analysis requirements (as described above). The ISO (International Organization for Standardization) develops standards across a wide range of areas, from screw threads to banking cards. The majority of ISO standards are specific to certain areas they are documented agreements containing technical specifications or precise criteria to be used... 

Receptor plasticity could be invoked as the underlying common trait of multiple receptors. For example, although the multiple adrenergic isoreceptors are similar, they react to the common neurotransmitter norepinephrine (2.4) in a quantitatively different manner. They also show a drug specificity that varies from organ to organ and differs in various species of animals. In subsequent chapters of this book, receptor multiplicity as the rule rather than the exception will become amply evident. It is to be hoped that, in time, the comparison of isoreceptor molecular structures will provide precise criteria for their differentiation. 

Future studies should strive to improve upon these HAS schemes so as to better discriminate between highly toxic samples by separating them into sub-classes. This, in turn, will allow for the development of more precise criteria for the disposal of... 

Analysis of an essential oil will tell us what compounds are present (qualitative analysis) and in what amounts (quantitative analysis). However, when considering the composition of any named oil it is difficult to lay down precise criteria. As with all products of natural origin, there will be variations according to growing conditions and how they are harvested, extracted and stored. Even if the species of plant is defined and the parts used for oil production are carefully controlled, variation in composition will occur. This has previously been explained in terms of chemotypes and will be examined in more detail for other essential oils later in this chapter. Even when examining a particular chemotype there will be differences in the amounts of constituents, although these are usually within a fairly narrow range. 

The precise criteria used to ascertain if a linear system of equations is determinate cannot be neatly extended to nonlinear systems of equations. Furthemore, the solution of sets of nonlinear equations requires the use of computer codes that may foil to solve your problem for one or more of a variety of reasons, a few of which are mentioned below. The problem to be solved can be written as... 

CVs shown apply at HDL cholesterol concentrations greater than 40 mg/dL. At lower concentrations, the precision criteria are based on standard deviation. Acceptable standard deviation is 2.0 mg/dL by July, 1997 and 1.7 mg/dL by 1998. 

Such an approach was trialled in the late 1990s as part of an initiative by the Environment Agency in the UK. It led to proposals for a quality control scheme for use within the Agency s Direct Toxicity Assessment programme for effluent assessment and control. The trial entailed an interlaboratory ring-test of four test methods using two toxicants (3,4-dichloroaniline and zinc sulphate) from which accuracy and precision criteria were estimated, as described below. 

How the disease or condition of interest will be diagnosed, that is, participating individuals need to be diagnosed as hypertensive. The protocol will state the precise criteria that constitute high blood pressure in this particular study, and how and by whom determining measurements will be taken. 

Criteria comprise both quantitative and qualitative properties. Often it is useful to define a criteria hierarchy Starting with a general criterion, which is hardly quantifiable, one looks for subcriteria to specify the general one, the subcriteria in turn may further specified, until a set of precise criteria is found, which may be quantified by attributes. 

The selection of entries for inclusion in a particular study on the basis of structural precision depends on the purpose of the study. In cases where structural changes are likely to be several times larger than the experimental uncertainties, then precision criteria should not be restrictive. If, however, we are looking for very small geometrical variations, as in structure-reactivity correlations, then only the most precise structures are satisfactory. Indeed, the degree of experimental precision and the degree of precision with which the chemical fragment should be defined (see Section 3.7.4) are interrelated criteria in structure correlation work. 

Nevertheless, it is clear that there are separations for which adsorplion is ihe proper choice. Although precise criteria for making this choice are not possible, several roagh criteria can be enumerated. In the following list, distillation is assumed lo be ihe chief competitor. 

More precise criteria of witchcraft were soon forthcoming. We are told, for example, that. . those who try to induce others to perform. . . evil wonders are called witches. And because infidelity in a person who has been baptized is technically called heresy, therefore such persons are plainly heretics. i ... 

For two known specified degradation products, A and B, the levels are expected to be between 0.1 and 0.3% therefore, the acceptance criteria are set at 0.1% absolute difference between labs with a 25% RSD precision criteria for each analyst per sample (triplicate sample preparations per lot)... 

Documented agreements containing technical specifications or other precise criteria to be used consistently as rales, guidelines, or definitions of characteristics, to ensure that materials, products, processes and services are fit for their purposes. 

A group with diverse backgrounds would be necessary to formulate and justify precise criteria for handling the critical decision. 

The participants were also surprised by the difficulties they encountered when they tried to formulate specific criteria for handling the decision about disconnecting the riser. This supports our third hypothesis, concerning the need for diverse backgrounds to formulate and justify precise criteria for handling the critical decision. 

We conclude that detailed discussions of specific incidents or scenarios involving conflicting goals are needed to make the boundaries towards unacceptable risk explicit and known, and to reveal the stakes involved in critical decisions. A group with diverse backgrounds proved necessary to formulate and justify precise criteria for handling the critical decision. The participants had not considered the whole range of possible outcomes of each decision option before they were asked to list those consequences. 

There has been some debate concerning the precise criteria used by Lavoisier, given that several of the entries fail to meet his stipulation that simple substances are the final products of chemical analysis. R. Siegfried, B.J. Dobbs, Composition, A Neglected Aspect of the Chemical Revolution, Annals of Science, 29,29-48,1982. 

An explosive or pyrotechnic article is an article containing one or more explosive or pyrotechnic substances or mixtures. GHS provides the overall and detailed scheme of procedure and precise criteria for subsequent classifications of substances, mixtures, or articles in this class of explosives. 

The single ground state AIMD-GDF dynamics is a useful tool to study the influence of the temperature on the structural properties of small metallic clusters allowing to find mechanisms of isomerization processes as well as to formulate precise criteria for phase transitions in finite systems... 

As regards the second question, precise criteria are listed below to which spectra must conform so as to be Fourier inverted into rotational time-correlation functions. Strictly,... 

An example of precision criteria for a gas chromatographic method would be that the instrument precision (RSD) should be 1%, and the repeatability of the method would be 2%. 

Detecting signals beyond human c ability Ignoring extraneous factors and making quantitative assessments Consistent application of precise criteria Storing information for long periods and recalling specific items with perfect accuracy... 

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