Principle of definition

Another important principle to remember in investigation is the principle of definition, which is A logical and proper decision can be made only when the basic or real problem is first defined. (Prescription without diagnosis is malpractice.)  

THE GOLDEN RULE OF ACCIDENT AND NEAR MISS INCIDENT INVESTIGATION 

The golden rule of accident and near miss incident investigation is Accident and near miss incident investigation is fact-finding and not fault-finding.  

In other words, use accidents and near miss incident investigation systems and methodology to get to the facts, the root causes of the accident, and don t use it to find fault. Finding fault will not help in identifying and removing the cause of accidents and near miss incidents. 

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In the meantime, the great French chemist Claude Louis Berthollet (1748-1822) had by 1801 arrived at the conclusion that chemical elements could react in different proportions so that the resulting compound could represent a continuum of proportions of its constituent elements (atoms). This led to a conflict between him and Proust, who in 1804 published results on metallic oxides, which indicated that Berthollet s results were caused by this investigator having analyzed mixtures of two oxides, or alternatively, of the metal and one of its oxides. The dispute continued for several years and it would seem that the two combatants held to their views until the end of their lives. Nevertheless, there can be no doubt that, by introducing the principle of definite proportions of the elements in a chemical compound, Proust has made a major contribution to modern chemistry. 

As stated by the principle of definition, if the real causes of accidents and near-miss incidents are not found, how can real solutions be proposed If all the contributing factors are not investigated, how can the causes of the events be identified and rectified ... 

Principle of definition A logical decision can be made only if the real problem is first defined. 

Principle. A definite amount of the substance ca. 25 mg.) is weighed out and transferred to a special Kjeldhal flask it is decomposed by digesting ith... 

This article is an iatroduction and survey that states the fundamental principles and definitions of catalysis, demonstrates the unity of the subject, and places it ia an appHed perspective. The selection of iadustrial catalytic processes discussed has been made for the sake of ikustrating principles and representative characteristics of catalysis and catalytic processes. Details of the processes are given ia numerous other articles ia the Eniyclopedia. 

The permeability relative to a pure liquid, usually water, may be determined with the help of different devices that operate on the principle of measurement of filtrate volume obtained over a definite time interval at known pressure drop and filtration area. The permeability is usually expressed in terms of the hydraulic resistance of the filter medium. This value is found from ... 

One molecule (or mole) of propane reacts with five molecules (or moles) of oxygen to produce three molecules (or moles) or carbon dioxide and four molecules (or moles) of water. These numbers are called stoichiometric coefficients (v.) of the reaction and are shown below each reactant and product in the equation. In a stoichiometrically balanced equation, the total number of atoms of each constituent element in the reactants must be the same as that in the products. Thus, there are three atoms of C, eight atoms of H, and ten atoms of O on either side of the equation. This indicates that the compositions expressed in gram-atoms of elements remain unaltered during a chemical reaction. This is a consequence of the principle of conservation of mass applied to an isolated reactive system. It is also true that the combined mass of reactants is always equal to the combined mass of products in a chemical reaction, but the same is not generally valid for the total number of moles. To achieve equality on a molar basis, the sum of the stoichiometric coefficients for the reactants must equal the sum of v. for the products. Definitions of certain terms bearing relevance to reactive systems will follow next. 

In 1923. Lewis published a classic book (later reprinted by Dover Publications) titled Valence and the Structure of Atoms and Molecules. Here, in Lewis s characteristically lucid style, we find many of the basic principles of covalent bonding discussed in this chapter. Included are electron-dot structures, the octet rule, and the concept of electronegativity. Here too is the Lewis definition of acids and bases (Chapter 15). That same year, Lewis published with Merle Randall a text called Thermodynamics and the Free Energy of Chemical Substances. Today, a revised edition of that text is still used in graduate courses in chemistry. 

It will be observed that the definition of intrinsic energy by means of the equation (c) implies in itself no physical law, since the value of (U2—Ui) can always be chosen so as to make the values of 2Q and 2A satisfy the equation. We shall now show that the value of (U2 — Ui) is uniquely so defined, and is quite independent of the way in which the process is executed. This is a physical law, which we shall call the Principle of Conservation of Energy. 

We may also speak of the pressure at a point in the interior of a mass of liquid or gas, because if a very small plane area removed from the immediate vicinity of one side, a definite force P must be applied to keep the area in position. From the principle of reaction we see that each of the two portions of fluid divided by an im a(f in ary plane opposite forces is called a stress. 

As soon as we had shown that is an available energy, from the definition of 39 and equation (13a), we could at once have inferred the relations (10)—(12) from the principle of dissipation of energy, for V must be a minimum in stable equilibrium. 

Definition of a medicai device Risk-based classification of devices Essential principles of safety and performance Labelling... 

By definition a minor element in seawater is one has a concentration less than Ippm(m). It is experimentally challenging to determine the total concentrations, much less their major chemical forms. Development of new analytical techniques has greatly extended our knowledge (Johnson et al, 1992). Because early data (prior to about 1975) was so erratic, the principle of oceanographic consistency was proposed as a test for the data (Boyle and Edmond, 1975). According to this principle the analyses of minor elements should ... 

It can be seen that these definitions are derived from experimental observation and are no more than classifications based on a set of properties shared by a group of substances. They are scientifically inadequate for the interpretation of results, which requires a definition based on concepts. Historically, the attempt to provide a model rather than a classification comes in the form of a search for imderlying universal principles. It seems that the alchemists recognized vague principles of acidity and alkalinity, and in the 17th century the iatrochemists made these the basis of chemical medicine. Disease was attributed to a predominance of one or other of these principles (Pattison Muir, 1883). 

Not surprisingly, there is no agreed definition of the risk management process. The associated issues and interactions can be very complex, and much effort continues to go into defining how they can be characterised. It is however possible to sketch the overall process into a coherent architecture, based on the principles of ... 

Independent reference methods - one organization Two or more independent reference methods, each based on an entirely conceptually different principle of measurement, independent in theory and experimental procedure, applied in replicate, within a single organization, of the highest reputational quality, by two or more expert analysts, working independently. The methods used can, naturally, include definitive methods, and the results should be corroborated by a third or additional, independently different, accurately characterized, well established, thoroughly validated, definitive, reference, or other methods. 

The three historical approaches to certification mentioned above were recently expanded to identily seven modes that are used at NIST for value assignment for chemical composition (May et al. 2000). These seven modes and the resulting values are summarized in Table 3.13. The basic principles of value assignment remain unchanged however, these modes now provide a well-defined link between the process used for value assignment and the definition of the assigned value (i.e. certified, reference, or information value). The terms described above provide a clear indication of the level of confidence that NIST has in the accuracy of the assigned value. The definition of a certified value implies that NIST must be involved in the measurement process for the value to be classified as a NIST certified value (see modes 1-3 in Table 3.13). Thus, modes 4 and 7, which do not involve NIST measure-... 

Let us start with a definition. Semiconductor chemical sensor is an electronic device designed to monitor the content of particles of a certain gas in surrounding medium. The operational principle of this device is based on transformation of the value of adsorption directly into electrical signal. This signal corresponds to amount of particles adsorbed from surrounding medium or deposited on the surface of operational element of the sensor due to heterogeneous diemical reaction. 

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