Terminology physical quantities

Symbols separated by commas represent equivalent recommendations. Symbols for physical and chemical quantities should be printed in italic type. Subscripts and superscripts which are themselves symbols for physical quantities should be italicized all others should be in Roman type. Vectors and matrices should be printed in boldface italic type, e.g., B, b. Symbols for units should be printed in Roman type and should remain unaltered in the plural, and should not be followed by a full stop except at the end of a sentence. References International Union of Pure and Applied Chemistry, Quantities, Units and Symbols in Physical Chemistry, Blackwell, Oxford, 1988 Manual of Symbols and Terminology for Physicochemical Quantities and Units, Pure Applied Chem. 31 577-638 (1972), 37 499-516 (1974), 46 71-90 (1976), 51 1-41, 1213-1218 (1979) 53 753-771 (1981), 54 1239-1250 (1982), 55 931-941 (1983) lUPAP-SUN, Symbols, Units and Nomenclature in Physics, PV ica 93A 1-60 (1978). 

Literature abounds with a rich terminology concerning the possible relationships between observations provided by experiment or analysis and parameters which are the physical quantities needed for a mathematical formulation of a process (the model) to be uniquely determined. A forward problem relates observations to parameters by a relationship such as... 

A substantial number of definitions in the terminology section are either of physical quantities or are expressed mathematically. In such cases, there are recommended symbols for the quantities and, when appropriate, corresponding SI units. Other terms have eommon abbreviations. The following format is used to indicate these essential eharaeteristics name of term (abbreviation), symbol, SI unit unit. Typical examples are tensile stress, interpenetrating polymer network (IPN). If there are any, alternative names or synonyms follow on the next line, and the definition on the sueeeeding lines. 

Already in 1968, Somasundaran [24] complained about use of the terms lEP and PZC outside their normal meaning. lEP and PZC are two different physical quantities, and they must be distinguished even when they happen to be numerically equal. Numerous examples of confusion between lEP and PZC can be found in the literature. For example, in [25], the lEP is termed the PZC. In such cases, the proper terminology has been used in the present book and the terminology used in the original papers has been ignored. 

This table lists some abbreviations, acronyms, and symbols encountered in the physical sciences. Most entries in italic type are symbols for physical quantities for more details on these, see the table Symbols and Terminology for Physical and Chemical Quantities in this section. Additional information on units may be found in the table International System of Units (SI) in Section 1. Many of the terms to which these abbreviations refer are included in the tables Definitions of Scientific Terms in Section 2 and Techniques for Materials Characterization in Section 12. Useful references for further information are given below. 

The terminology used has undergone the usual changes or refinements with time and experience. The terms mechanism of dissociative vaporization , physical approach , and specific enthalpy , introduced in previous communications by the author, have been replaced in this book by mechanism of congruent dissociative vaporization , thermochemical approach , and molar enthalpy . The notation of some physical quantities has likewise undergone changes. 

There is international agreement that the units used for physical quantities in science and technology should be those of the International System of Units, or SI (standing for the French Systeme International d Unit s). The Physical Chemistry Division of the International Union of Pure and Applied Chemistry, or lUPAC, produces a manual of recommended symbols and terminology for physical quantities and units based on the SI. The manual has become known as the Green Book (from the color of its cover) and is referred to here as the lUPAC Green Book. This book will, with a few exceptions, use symbols recommended in the third edition (2007) of the lUPAC Green Book these symbols are listed for convenient reference in Appendices C and D. 

The International Union of Puie and AppUed Chemistry now recommends a standard pressure of 0.1 MPa (1 bar) in place of the previously accepted standard of 101.325 kPa (1 atm). The difference in thermodynamic quantities is not significant for condensed phases, and differences in A// values are not significant even for gases, but the user of thermodynamic tables will have to note carefully the standard state chosen for any compilation of data. See Ref. 1, pp. 2—23 lUPAC Division of Physical Chemistry, Commission on Symbols, Terminology and Units, Manual of symbols and terminology for physico-chemical quantities and units, M. L. McGlashan, M. A. Paul, and D. N. Whiffen, eds., Pure andApp. Chem 51, 1 (1979), and Appendix IV, Pure and Applied Chem. 54, 1239 (1982). 

IAMAP, Terminology and Units of Radiation Quantities and Measurements, Radiation Commission of the International Association of Meteorology and Atmospheric Physics, Boulder, CO, 1978. 

Because for historical reasons the quantity i is imaginary, everything it multiplies suffers the same terminological fate. However, it is not true to think that the part of a mathematical expression that contains i is unreal in a physical sense. It is just as real as the first part. 

This Part II of Appendix IIf to the Manual of Symbols and Terminology for Physicochemical Quantities and Units (hereinafter referred to as the Manual) has been prepared by the Commission on Colloid and Surface Chemistry of the Division of Physical Chemistry of the International Union of Pure and Applied Chemistry. It is the outcome of extensive discussions within the Commission5 and its Task Force headed by Professor Burwell, with other... 

Manual of Symbols and Terminology for Physic ochemical Quantities and Units (1973 Edn.), prepared for publication by M. L. McGlashan and M. A. Paul, Butterworths, London (1975). 

Refs. [i] Mills I, Cvitas T, Homann K, KallayN, Kuchitsu K (eds) (1993) IUPAC quantities, units and symbols in physical chemistry Blackwell Scientific Publications, Oxford, p 59-61 [ii] Parsons R (1974) Manual of symbols and terminology for physicochemical quantities and units. Appendix III. Electrochemical nomenclature. Pure Appl Chem 37 503... 

The first IUPAC Manual of Symbols and Terminology for Physicochemical Quantities and Units (the Green Book) of which this is the direct successor, was published in 1969, with the object of securing clarity and precision, and wider agreement in the use of symbols, by chemists in different countries, among physicists, chemists apd engineers, pnd by editors of scientific journals . Subsequent revisions have taken account of many developments in the field, culminating in the major extension and revision represented by the 1988 edition under the simplified title Quantities, Units and Symbols in Physical Chemistry. 

Everett, D.H. lUPAC—division of physical chemistry, manual of symbols and terminology for physicochemical quantities and units—appendix II definitions, terminology and symbols in colloid and surface chemistry. Pure Appl. Chem. 1992, 31 (4), 577-638. 

The symbols and terminology for physicochemical quantities and units are those recommended by lUPAC through its Physical Chemistry Division. For the thermodynamic notation needed but not specified by these two sources, the recommendations of the Bulletin of Chemical Thermodynamics are used. Similarly, for spectroscopic nomenclature, the common practice of Moore and Herz-berg " is followed. 

The lUPAC Green Book has a long history going back to 1969 when the Manual of Symbols and Terminology for Physicochemical Quantities and Units was first pubhshed by M. L. McGlashan, the then Chainnan of the lUPAC Physical Chemistry Division. The first edition of the Green Book as we know it now was pubhshed in 1988 and the third, revised and enlarged edition was published recently by lUPAC with RSC [1]. 

In this section the population balance modeling approach established by Randolph [95], Randolph and Larson [96], Himmelblau and Bischoff [35], and Ramkrishna [93, 94] is outlined. The population balance model is considered a concept for describing the evolution of populations of countable entities like bubble, drops and particles. In particular, in multiphase reactive flow the dispersed phase is treated as a population of particles distributed not only in physical space (i.e., in the ambient continuous phase) but also in an abstract property space [37, 95]. In the terminology of Hulburt and Katz [37], one refers to the spatial coordinates as external coordinates and the property coordinates as internal coordinates. The joint space of internal and external coordinates is referred to as the particle phase space. In this case the quantity of basic interest is a density function like the average number of particles per unit volume of the particle state space. The population balance may thus be considered an equation for the number density and regarded as a number balance for particles of a particular state. 

THERMAL CONDUCTIVITY. The proportionality constant A is a physical property of the substance called the thermal conductivity. It, like the newtonian viscosity ft, is one of the so-called transport properties of the material. This terminology is based on the analogy between Eqs. (3.4) and (10,2). In Eq. (3.4) the quantity xg,. is a rate of momentum flow per unit area, the quantity du/dy is the velocity gradient, and jx is the required proportionality factor. In Eq. (10.2), q/A is the rate of heat flow per unit area, dTIdn is the temperature gradient, and k is the proportionality factor. The minus sign is omitted in Eq. (3.4) because of convention in choosing the direction of the force vector. 

II. 1.2 Symbols and terminology The symbols for physical and chemical quantities used in the TDB review follow the recommendations of the International Union of Pure and Applied Chemistry, lUPAC [79WHI], [93MIL/CVI], They are summarised in Table II-2. Table II-2 Symbols and terminology. ... 

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