Size term, definition

A subcritical aggregate having fewer subunit components than a nucleus. When this term is applied in the kinetics of precipitation, n refers to the number of subunits in a particle and n defines the number of subunits in a particle of critical size. This definition avoids confusion by distinguishing between subcritical (n < n subunits), critical (n = n subunits), and supercritical (n > n subunits) particle sizes. If a nucleus is defined as containing n n subunits, then an embryo contains n n subunits. Note that in this treatment, we are not using a phase-transition description to describe nucleation, and we are focusing on the smallest step in the process that leads to further aggregation. 

Sometimes the term clay is used synonymously with the term soil. In addition, Moore (1996) commented that clay is used in three different ways as a size term, as a rock term and as a mineral term. Now that we have a clear and definite idea about what cl is, the confusion regarding such varied use of this term may be eleared. 

Clay as a size term It is not imcommon in sedimentology to refer all sediments having grainsize <1/256 mm (<4 pm) as clays. But such a usage does not conform to the definition of clay, since all materials of that grainsize are not plastic or do not harden on drying or firing. The use of clay as a size term is therefore not acceptable. 

Classically, aerosols are particles or droplets that range from about 0.15 to 5 p.m ia size and are suspended or dispersed ia a gaseous medium such as air. However, the term aerosol, as used ia this discussion, identifies a large number of products which are pressure-dispensed as a Hquid or semisohd stream, a mist, a fairly dry to wet spray, a powder, or even a foam. This definition of aerosol focuses on the container and the method of dispensiag, rather than on the form of the product. 

The term composite materialis used to describe macroscopic combiaations of two or more materials. Macroscopic combiaations are specified to exclude alloys that consist of materials combined on a microscopic scale (1). Such an exclusive definition of composite materials is not universal, but it is commonly accepted and it helps restrict to a manageable size an introductory treatment of the science and technology of composite materials. 

However, in accordance with the definition of a stationary point. Equation (B.1), the first term in Equation (B.3) for AV vanishes irrespective of the value or size of h so that... 

The term particle and particle size are so highly ambiguous as to require precise definition. As used in this article particles will.be limited by size to those distinct entities which have physically detectable boundaries in any direction within the limits of 0.05 and 10 microns (1 micron, p -0.001mm). This size range covers those particles which can be directly measured without magnification down to those which exhibit colloidal behavior... 

For definitions of axial, equatorial, and related terms for rings of any size, see Anet, F. A.L. Tetrahedron Lett., 1990, 31, 2125. 

According to their diameter, pores are conventionally classified as macropores (J>50nm), mesopores (2< J<50nm) and micropores (J<2nm). For nanometer-sized pores the term nanopores has been also used for some time (Handbook of Porous Solids, F. Schiith, K. Sing, J. Weitkamp (eds.), Wiley-VCH, Berlin, 2002) but the definition of nanopores is not fully established. In this chapter the term nanopore will be used for pores with 1 < J < 10 nm. 

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