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Three-point differentiation formulas

The NONLIN module is responsible for intializing the concentration vector, C(t), for l i NRCT. Here NRCT is the number of reactants. If there are no equilibrium reactions, then C i) is set to IC i), the initial concentration vector, for 1 < f < NRCT. If equilibrium reactions do exist, then the type (2) equations (with derivatives set to zero) and the Type (1) and Type (3) equations are all solved simultaneously for the equilibrium concentrations of all reactants. Because the equilibrium equations are generally nonlinear, the Newton-Raphson iteration method is used to solve these equations. Also, since there is no symbol manipulation capability in the current version of CRAMS, numerical differentiation is used to calculate the required partial derivatives. That is, the rate expressions cannot at this time be automatically differentiated by analytical methods. A three point differentiation formula is used 27) ... [Pg.59]

Use of Interpolation Formula If the data are given over equidistant values of the independent variable x, an interpolation formula such as the Newton formula (see Refs. 143 and 18.5) may be used and the resulting formula differentiated analytically. If the independent variable is not at equidistant values, then Lagrange s formulas must be used. By differentiating three- and five-point Lagrange interpolation formulas the following differentiation formulas result for equally spaced tabular points ... [Pg.471]

The aim of the more popular of the colom scales is to represent colours in a three-dimensional colom space, such that similar visual colom difieiences are represented by approximately similar distances in the colom space. Such colour scales are known as uniform scales. The original CIE scales, represented diagrammatically in Fig. 5.3, were not intended for identifying the colours of objects and are certainly not uniform in spacing colours according to their visual differences. Over the last forty years the Commission Internationale de I Eclairage (CIE) in particular have worked to try to stem the confusion caused by the presence of the many formulae in use and standardise colom space. They managed to combine the opponent chromatic attributes used by Hunter and Schofield, with the MacAdam cube-root simplification of the earlier Judd polynomial. The result was the publication of CIELAB (or ClEL a b ) in 1976 (Smith 1997). At this point, the asterisk snperscript was introduced in order to differentiate the CIELAB parameters from other similar ones still in use. [Pg.86]

Differentiate between the formula equation, the complete ionic equation, and the net ionic equation. For each reaction in Question 6, write all three balanced equations. What is an acid-base reaction Strong bases are soluble ionic compounds that contain the hydroxide ion. List the strong bases. When a strong base reacts with an acid, what is aiways produced Expiain the terms titration, stoichiometric point, neutralization, and standardization. [Pg.170]

There are four amides with the formula C3H7NO. (a) Write their structures, (b) One of these amides has a melting and a boiling point that are substantially lower than those of the other three. Which amide is this Explain your answer, (c) Explain how these amides could be differentiated on the basis of their IR spectra. [Pg.102]

Typical chemical engineering curriculums consist of the equivalent of three semesters of calculus capped off by a course in elementary ordinary differential equations. This usually occurs within the first two years of a four-year program (five years, if co-op is an option). The next two or three years are usually dedicated to solving unit operation problems using prederived formulae. The point being, with few exceptions, the use of the four semesters worth of mathematics is not applied until the first year of graduate school. [Pg.465]

Differential Method In order to use the differential method of data analysis, it is necessary to differentiate the reactant concentration versus space-time data obtained in a plug-flow PBR. There are three methods of differentiation that are commonly used (i) graphical equal-area differentiation, (ii) numerical differentiation or finite difference formulas, and (iii) polynomial fit to the data followed by analytical differentiation. The aim of differentiation is to obtain point values of the reaction rate ( Ra)p at each reactant concentration Q4 or conversion xa or space time (.W/Fao), as required. All three differentiation methods can introduce some error to the evaluation of -Ra)p- Information on and illustration of the various differentiation techniques are available in the literature [23, 26]. [Pg.31]

Basic formulas. Let us consider a differentiable function f(x) at three consecutive equidistant locations x i i,x , and x j+j, where i-1, i, and i+1 are indexing parameters. Here, we will assume that all grids are uniformly separated by the constant grid block distance Ax. Now, it is clear from Figure 20-1 that the first derivative at an intermediate point A between x i.j and x is... [Pg.374]


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Three point

Three-point formulas

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