Classification physical

The physical classification of the war gases has often been proposed by taking as criterion either their state of aggregation, or their boiling point. 

The method of classification most used to-day is based on their state of aggregation at ordinary temperatures. According to this classification the war gases are divided as follows into three groups  

Liquid. Bromine, chloropicrin, dichloroethyl sulphide (mustard gas), etc. 

Diphenyl chloroarsine, diphenyl cyanoarsine, chloroacetophenone, etc. 

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Schemes for classifying surfactants are based upon physical properties or upon functionality. Charge is tire most prevalent physical property used in classifying surfactants. Surfactants are charged or uncharged, ionic or nonionic. Charged surfactants are furtlier classified as to whetlier tire amphipatliic portion is anionic, cationic or zwitterionic. Anotlier physical classification scheme is based upon overall size and molecular weight. Copolymeric nonionic surfactants may reach sizes corresponding to 10 000-20 000 Daltons. Physical state is anotlier important physical property, as surfactants may be obtained as crystalline solids, amoriDhous pastes or liquids under standard conditions. The number of tailgroups in a surfactant has recently become an important parameter. Many surfactants have eitlier one or two hydrocarbon tailgroups, and recent advances in surfactant science include even more complex assemblies [7, 8 and 9].

Particularly useful is the physical classification of surfactants based on the hydrophile-lipophile balance (HLB) system [67,68] established by Griffin [69,70]. More than 50 years ago he introduced an empirical scale of HLB values for a variety of nonionic surfactants. Griffin s original concept defined HLB as the percentage (by weight) of the hydrophile divided by 5 to yield more manageable values ... 

The physical classification of the boundaries is made according to the shape of the generalized diffusivity profile across the boundary, D(x), where x is a spatial coordinate perpendicular to the boundary (Fig. 19.3). Three types of boundaries are distinguished ... 

Physical classification, such as solids, oral liquids, semisolids, and parenteral products... 

The nature of the input signals (physical classifications and consequences). 

Physical Classification This method of classification attempts to examine toxic agents according to the form in which they exist in the occupational environment. These classifications include solids, liquids, gases, and vapors. 

The physical classification dilTerentiates three types of electrochromic materials. Type I electrochromic materials are always in solution. MetaUic ions belong to this class. Type II electrochromic materials are colourless and in solution at one state and coloured and solid at the other state. Heptyl viologen is type II. Type in electrochromic materials are always solid. Most electrochromic materials are type HI, including conducting polymers or metal oxides [59,60]. 

Currently, there are three classifications of grown-in microdefects experimental classification, technological classification and physical classification. 

An excess concentration of intrinsic point defects (vacancies or silicon self-interstitials) arises when the crystal is cooled under certain thermal conditions (Cho et al., 2006). This process leads to the formation of secondary grown-in microdefects (A-microdefects or microvoids) (V.l. Talanin LE. Talanin, 2004). We have proposed the physical classification of grown-in microdefects. It is based on the differences in the physical nature of the formation of primary and secondary grown-in microdefects (V.l. Talanin LE. Talanin, 2006a). 

Talanin, V.I. Talanin, I.E. (2004). Mechanism of formation and physical classification of the grown-in microdefects in semiconductor silicon. Defect Diffusion Forum, Vol. 230-232, No. 1, pp. 177-198, ISSN 1012-0386. 

The next separation of class 2.2 does not bring anything new regarding the physical classification. The elements of class 2.2.2 show positive oxidation states higher on average than those of the elements of class 2.2.1. Near the border of the two classes lie C and Ir, followed by Mo and Hf. 

The last division of class 2.2.1 is also identical to that obtained by the physical classification. The elements of class 2.2.1.1 (Ru, Hf, and Ir) have a higher affinity toward chlorine than those of class 2.2.1.2 (Rh and Pt). To the former class are related to some extent Mo and C and to the latter Pd, Th, and Nb. 

Additionally, Defra is undertaking a physical classification of the hih and upland areas of Grades 4 and 5 which will be divided into two main categories ... 

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