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The theory is initially presented in the context of small deformations in Section 5.2. A set of internal state variables are introduced as primitive quantities, collectively represented by the symbol k. Qualitative concepts of inelastic deformation are rendered into precise mathematical statements regarding an elastic range bounded by an elastic limit surface, a stress-strain relation, and an evolution equation for the internal state variables. While these qualitative ideas lead in a natural way to the formulation of an elastic limit surface in strain space, an elastic limit surface in stress space arises as a consequence. An assumption that the external work done in small closed cycles of deformation should be nonnegative leads to the existence of an elastic potential and a normality condition. [Pg.118]

Also, an alternative formulation of equation (17) can be conceived if one wants to distinguish between ground state, monoexcitations, biexcitations,. .. and so on. Such a possibility is symbolized in the following Cl wavefunction expression for n electrons, constructed as to include Slater determinants up to the p-th (pp) unoccupied ones l9klk=i,ni Then, the Cl wavefunction is written in this case as the linear combination ... [Pg.238]

While it is desirable to formulate the theories of physical sciences in terms of the most lucid and simple language, this language often turns out to be mathematics. An equation with its economy of symbols and power to avoid misinterpretation, communicates concepts and ideas more precisely and better than words, provided an agreed mathematical vocabulary exists. In the spirit of this observation, the purpose of this introductory chapter is to review the interpretation of mathematical concepts that feature in the definition of important chemical theories. It is not a substitute for mathematical studies and does not strive to achieve mathematical rigour. It is assumed that the reader is already familiar with algebra, geometry, trigonometry and calculus, but not necessarily with their use in science. [Pg.1]

Let us use a control volume approach for the fluid in the boundary layer, and recognize Newton s law of viscosity. Where gradients or derivative relationships might apply, only the dimensional form is employed to form a relationship. Moreover, the precise formulation of the control volume momentum equation is not sought, but only its approximate functional form. From Equation (3.34), we write (with the symbol implying a dimensional equality) for a unit depth in the z direction... [Pg.380]

Thus, to completely solve the problem of symmetry reduction within the framework of the formulated algorithm above, we need to be able to perform steps 3-5 listed above. However, solving these problems for a system of partial differential equations requires enormous amount of computations moreover, these computations cannot be fully automatized with the aid of symbolic computation routines. On the other hand, it is possible to simplify drastically the computations, if one notes that for the majority of physically important realizations of the Euclid, Galileo, and Poincare groups and their extensions, the corresponding invariant solutions admit linear representation. It was this very idea that enabled us to construct broad classes of invariant solutions of a number of nonlinear spinor equations [31-33]. [Pg.278]

Linear. Since mass and energy are linearly related between modules, purely linear flowsheet calculations can be formulated as a solution to a set of linear equations once linear models for the modules can be constructed. Linear systems, especially for material balance calculations can be very useful (16). Two general systems, based on linear models, SYMBOL (77) and MPB II (7 ) are indicated in Table 1. MPB II is based on a thesis by Kniele (79). If Y is the vector of stream outputs and the module stream inputs are X, then as discussed by Mahalec, Kluzik and Evans (80)... [Pg.26]

In 1884 Svante Arrhenius advanced the then very revolutionary hypothesis that salts dissolved in aqueous solutions tend to ionize partially or completely. Such a process may be represented by an equation of the form Mv Ai, (aq) = v i M + -1- v A - where M and A represent the cationic and anionic constituent of the compound, z+ and z- are their appropriate ionic charges and y+ and v, the stoichiometry numbers. The ionization process symbolized above requires that My Ay itself be considered either as a dissolved species that may be equilibrated with the undissolved compound in a saturated solution or that exist as such. This formulation also hides a multitude of difficulties in many cases the ionization process is much more complex than indicated above. For example, in the ionization of Agl one encounters in aqueous solution the species Agl, Ag+, I , Agl2, Ag2l", and several more exotic combinations. In what follows we limit ourselves to cases where there is a great preponderance of the elementary species over the more complex aggregates. [Pg.249]

In Eq. (2.1) the accumulation term refers to a change in mass or moles (plus or minus) within the system with respect to time, whereas the transfers through the system boundaries refer to inputs to and outputs of the system. If Eq. (2.1) is written in symbols so that the variables are functions of time, the equation so formulated would be a differential equation. As an example, the differential equation for the O2 material balance for the system illustrated in Fig. 2.1 might be written as... [Pg.107]

The functional above was used already by Gauss [12] to study classical trajectories (which explains our choice of the action symbol). Onsager and Machlup used path integral formulation to study stochastic trajectories [13]. The origin of their trajectories is different from what we discussed so far, which are mechanical trajectories. However, the functional they derive for the most probable trajectories, O [X (t)] is similar to the equation above ... [Pg.447]

There are ample self-made misconceptions regarding the formulation of reaction symbols. Mulford and Robinson [32] discovered the following situations regarding questions 5 and 6 (see Fig. 5.21) when evaluating the empirical studies Responses to question 5 suggest that students came to us with a very poor understanding of chemical formulas and equations. Only 11 % selected the correct answer d. When we consider the number of students who selected responses a, c and e, we see that 65% chose responses that do not conserve atoms. Combining responses a, b and e indicates that 74% appear not to understand the difference between the coefficient 2 and the subscript 3 in 2 S03 [32],... [Pg.125]

The volume of the oil phase (in mL) solubilized per gram of surfactant used at the conditions where equations 8.10 or 8.11 are equal to zero ( optimum salinity ) is called the solubilization parameter at optimum formulation and symbolized by SP. The interfacial tension under these conditions, y, is inversely proportional to the SP, and y = K/(SP )2 (Chun, 1979). Consequently, to obtain the lowest interfacial tension (Chapter 5, Section IIIA), the value of SP should be maximized. [Pg.319]

In order to apply one of the proposed sets of elements for describing coorbital motion we formulate the equations of motion (1) of the weakly coupled Kepler motions in terms of the Levi-Civita coordinates of Section 2. In this way the unperturbed problem will be defined by linear differential equations. Using the symbols pj = mo + nij, j = 1,2 as well as complex notation iq, r2 C and the abbreviations fi, f2 C for the right-hand sides, equation (1) reads as... [Pg.237]

State the mathematical formulation of the Beer-Lambert-Bouguer Law and explain the meaning of each symbol in the equation. [Pg.113]

A model may be defined as the simplified repn sentatioH of a defined physical system. The representation is developed in symbolic form and is frequently expressed in mathematical equations and uses physical and or chemical principles based on scientific knowledge, experimental judgment, and intuition, all set on a logical foundation. A model may be theoretical or empirical, but the formulation of an accurate model is a requirement for the successful solution of any problem. [Pg.18]

In (3.118), the concise form of writing of several constitutive equations with the same variables was used, i.e., here T stands for constitutive functions s, u, q, T respectively (overhead symbol differs function from its value rare exclusion, see, e.g., Sect. 3.2). Because the response as well as the independent variables are functions of X and t, we add in (3.118) also explicit dependence on these quantities. In formulation of constitutive equations (3.118) the constitutive principle of equipresence was used in all constitutive equations (3.118) we used the same independent variables. This prevents the unjustified preference of some of such equations it is a rather plausible rule, cf. Rem. 25, Sect. 2.1, which in special cases, e.g. [28, 60], may be left. [Pg.100]

Multiple parameter fault isolation by means of minimisation of least squares of ARR residuals needs residual parameter sensitivity functions if a gradient search based method is used. If ARRs can be derived in closed symbolic form from a bond graph, their analytical expressions can be used in the formulation of the least squares cost function and can be differentiated with respect to the vector of targeted parameters either numerically or residuals as functions of the targeted parameters can be differentiated symbolically. If ARRs are not available in symbolic form, they can be numerically computed by solving the equations of a DBG. [Pg.140]

This means that the mathematical model to be deduced will consist of two explicit differential equations including resistor currents and a set of coupled implicit algebraic equations for the outputs of the resistors and the input of the controlled source. As the model is linear, these algebraic equations could be solved symbolically turning the DAE system into an explicit ODE system. Alternatively, the DAE system could be directly formulated in the Scilab script language and evaluated by the DASSL solver. [Pg.261]


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Equation Symbolism

Symbolic formulation

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