Scientific classification

With foams, one is dealing with a gaseous state or phase of matter in a highly dispersed condition. There is a definite relationship between the practical application of foams and colloidal chemistry. Bancroft (4) states that adopting the very flexible definition that a phase is colloidal when it is sufficiently finely divided, colloid chemistry is the chemistry of bubbles, drops, grains, filaments, and films, because in each of these cases at least one dimension of the phase is very small. This is not a truly scientific classification because a bubble has a film round it, and a film may be considered as made up of coalescing drops or grains. ... 

The proposed tiers are not obligatory but contain extrapolation tools that can be used differently in a number of situations and, in some cases, regulatory protocols, in which certain combinations of extrapolation methods are prescribed as methods that must be used for the assessment, such as in the formal registration of pesticides. The proposed tiered system is based on a scientific classification of the available extrapolation method types. With ideal data and concepts for extrapolation, this scheme may be expected to yield reduced degrees of overestimation of risk when moving up the tiers from Tier-0 to Tier-4 (i.e., risks are more precisely estimated in the higher tiers). 

As any scientific classification creates problems of definition, so our present classification based on oxidation state leads to difficulty in the placing of material. This is particularly, but not exclusively, true of nitrosyls. 

A scientific classification should be based first on the fundamental properties of the vitrinite in coals. This means, at the very least, that element concentrations and molecular structure configurations must be assessed. The structural properties of most importance to classification and process responses appear to be the following ... 

For the development of a scientific classification, these determinations need to be made on many vitrinite-rich coal samples spanning a wide range of rank. Because coals are sensitive to oxidation and moisture... 

Besides the classification of the elements and compounds, there are related chemical systems that illustrate the intricacies and not quite hierarchical structure of scientific classification schemes. Molecular systems that crystallize are further classified by crystal structure. Organic molecules have an elaborate system of classification called "nomenclature" based on both their chemical composition and their symmetries. The classifications are correlated with properties that do not define the classification. Thus, the classification of the elements is associated with a numerical property—atomic weight—and molecular symmetries are associated with optical activity. What are the formal structures that make multiple classifications correct, and how does the existence of one classification scheme constrain others What is the purpose, methodological or otherwise, of corresponding properties Chemistry provides our most familiar examples of settled scientific classifications, and when we want to know what makes for such certainty, chemistry is where we should look. 

Species Scientific classification of plants and animals uses a hierarchy of groups including class, family, and a number of others. Species is a very specific group of organisms that can mate and produce sexually viable offspring. Modern humans belong to the genus Homo and the species sapiens. 

An enormous number of viruses have been identified since 1892, when the Russian researcher Dmitri Ivanovski first isolated the tobacco mosaic virus. Because their origins and evolutionary history are unclear, the scientific classification of viruses has been difficult. Often, viruses have been assigned to groups according to such properties as their microscopic appearance (e.g., rhabdoviruses have a bullet-shaped appearance), the anatomic structures where they were first isolated (e.g., adenoviruses were discovered in the adenoids, a type of lymphoid tissue), or the symptoms they produce in a host organism (e.g., the herpes viruses cause rashes that spread). In recent years, scientists have attempted to develop a systematic classification system based primarily on viral structure, although several other factors are also important (e.g., host and disease caused). 

The scientific classification of materials according to their flow behavior... 

The scientific classification of materials according to their flow behavior corresponds, in a limited sense, to the classification according to their commercial application. A distinction is made here between thermo-plasts, fibers, elastomers, and thermosets. This classification naturally only applies at the application or processing temperature under consideration. 

A logical and scientific classification of corrosion processes, although desirable, is by no means simple, owing to the enormous variety of corrosive environments and the diversity of corrosion reactions, but the broad classification of corrosion reactions into wet or dry is now generally accepted, and the terms are in common use. The term wet includes all reactions in which an aqueous solution is involved in the reaction mechanism implicit in the term dry is the absence of water or an aqueous solution. 

A more scientific classification takes into account resin structure. One can thus distinguish between aliphatic, cycloaliphatic, aromatic, and mixed HRs. Cycloaliphatic HRs include terpenic resins and cyclopentadiene-based resins. A similarity can be noticed, likely to cause confusion, between aliphatic and cycloaliphatic resins. This is because aliphatic resins often contain cyclic structures, arising from the presence of cyclopentadiene and cycloolefins in monomer mixtures subjected to polymerization and from cyclization accompanying some of the polymerization processes. Aromatic HRs include the products produced by polymerization of Cs-Cio fractions and CIRs. Mixed resins are made up of complex structures. Their properties will be modulated in terms of component proportion. Thus, these resins can produce various materials that also prove valuable from the technical point of view [8]. 

Seafood also includes shellfish— which is a commercial, rather than a scientific classification. Shellfish refers to hard-covered, edible, mostly marine animals from two different groups the mollusks (oysters, clams, mussels) and the crustaceans (crabs, lobsters, and sometimes shrimp). Among the important mollusk species, harvested from both wild and cultivated stocks, are oysters, hard clams, surf clams, quahogs, soft-shell clams, razor clams, and horse clams. 

Although the physical and chemical properties of refractory compounds have not been sufficiently studied, it is nevertheless possible to suggest principles of their scientific classification as bases for the subsequent extension of research and approach to solution of the problem of producing refractory compounds having predetermined properties. 

Aerosols can be subdivided according to the physical form of the particles and their method of generation. There is no strict scientific classification of aerosols. The following definitions correspond roughly to common usage and are precise enough for most scientific description. 

Problems arose through the fact that some tribes may keep their curare in more than one type of container, nowadays even in tin cans or bottles which happen to be conveniently at hand (14 pp. 138-140). In addition, since certain tribes have been renowned for the quality of their curare, there has been, and still is, a considerable trade in the product and samples often travel hundreds of kilometers from their place of origin (Section 1.2.5). With the gradual increase in knowledge of the botany and chemistry of curare, the essentially utilitarian, rather than scientific, classification by container has outlived its usefulness and the time has now come to give it a decent burial. It will not be referred to further in the present account. 

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