Arbitrary classification

Hardness in water varies widely, and as an arbitrary classification ... 

Distinguishing between physical and chemical adsorption using the value of adsorption heat cannot lead to unambiguous results, too. An arbitrary classification of physical adsorption as having small heats Q - 0.01 + 0.2 eV typical for and attributing - 1 eV to diemisorption is often violated. A typical example can be provided by a dissipative chemisorption diaracterized by small total heat effect. 

Such more or less arbitrary classification reflects three different physical situations. 

For films. Table 4.1 proposes an arbitrary classification of the polyethylene subfamilies (where m indicates metallocene catalysis). 

The arbitrary classification of Rauwolfia alkaloids (91) is simplified here, and it is slightly different from a recent arrangement (92). The Rauwolfia alkaloids can all be regarded as yohimbinoid derivatives as shown in Chart I, viz. the yohimbines (all yohimbine isomers) 18-hydroxyyohimbines (reserpine-type alkaloids) ring E heterocycles and their anhydronium analogs (ajmalicine, serpentine) ajmaline-type (which includes sarpagine) and compounds of unknown constitution. 

Consider an arbitrary classification of the nuclei of the molecule into various families... 

As field data and job records accumulate, these may point to the desirability of minor modifications to grouts and catalysts. Also, of course, new catalyst systems and additives may be developed that improve grout properties or ease of application. These end products must be looked at carefully to avoid the fallacy of arbitrary classification as new products, and thus divorcing them from histories of performance and permanence which may be totally applicable. 

Product Price. A somewhat arbitrary classification of chemicals into high, intermediate, and low price is as follows ... 

Boehm and Johnson Matthey titrations. Both titrations give information on the acidic or basic character. The procedures are described in [13] and [14]. Boehm method classifies the surface acidic sites in three types (called phenolic, lactonic, carboxylic), by growing strength of acidity. However, this arbitrary classification fails to attribute one surface acidic group to one type of acidity. Moreover, this method does not give very accurate results with solids containing few acidic sites. Nevertheless, it appears for our active carbon that "phenolic" sites are a majority. The amount of each type of acidic sites does not change very much with the nitric treatment. 

These are arbitrary classifications of chromatographic techniques, and some types of chromatography are considered together as a separate technique, such as gas chromatography for gas-solid and gas-liquid chromatography. In every case, successive equilibria are at work that determine to what extent the analyte stays behind or moves along with the eluent (mobile phase). In column chromatography, the column may be packed with small particles that act as the stationary phase... 

The continuous and wide spectrum of cell designs and reactor processes may be conveniently subdivided according to one of several arbitrary classifications ... 

Separation of Solids from Solids in Liquids. The resistance offered to the fall of particles through a liquid is used in several methods of separation of particles. Some of these methods depend principally on differences in particle size and others on differences in specific gravity. All these schemes were developed in the metallurgical industry, where they are used to a much greater extent than in the chemical industry. The following arbitrary classification is offered for this equipment ... 

The hypnotic drugs are not characterized by common structural features. Instead, a wide variety of chemical compounds have been used in clinical therapy. An arbitrary classification is as follows ... 

The six classified types of cases have been subclassified (M7, M29, M30) on the bases of clinical symptomatology, mode of genetic transmission, and nature of the glycosaminoglycan present in excess in the urine, and have been assigned type numbers (Table 2). However, even acceptance of this somewhat arbitrary classification of types of hereditary glycosaminoglycanuria does not yield complete simplicity since hyperglycosaminoglycanuria is not always present. The best classification of these diseases would be based on the chemical aspects—the primary enzymic defect, but unfortunately this is not yet possible since the specificities of even the enzymes that have been implicated need to be investi-... 

There many naturally occurring polymeric materials. Many are quite complex. It is possible, however, to apply an arbitrary classification and to divide them into six main categories. These are ... 

One of the scientific benefits we have already derived from the study of Antarctic meteorites is that a significant number of the specimens that have been collected there are nngronped, which means that they do not fit into the arbitrary classification scheme that has been devised (Table 18.1). The nngrouped meteorite specimens expand the classification and provide new and additional insight into the origin and evolution of the solar system. 

Cost savings are induced by the avoidance of arbitrary classifications. The gain in safety is to have defined a clear classification approach combining the functional needs (accident mitigation, prevention and management) and the mechanical ones depending on the environmental consequences. 

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