Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Mathematical limit definition

It may help to think of e as a desired precision or allowable error. In physics problems or other applications, there is usually a particular precision, determined by experimental constraints. For instance, if the best ruler one has is marked in tenths of a centimeter, one could not expect the precision of measurement to be much less than one-hundredth of a centimeter (e = 0.001 centimeters). In this case, two lengths that differ by less than 0.001 centimeters are indistinguishable. In mathematics, we are interested in truths that transcend the limitations of any one particular experimental setup hence our Definition 3.14 applies only if we can use elements of S to approximate v to any precision, no matter how small. Approximation is closely related to mathematical limits see Exercise 3.33. [Pg.96]

In this mathematical limit, the upper limit of integration becomes larger and larger without bound. Notice that the word limit has several definitions, and two of them unfortunately occur here in the same sentence. [Pg.135]

Markov tried to consolidate aU work of others on effective computability. He has introduced the term of algorithm in his 1954 book Teoriya Algorifmov [2]. The term was not used by any mathematician before him and reflects a limiting definition of what constitutes an acceptable solution to a mathematical problem ... [Pg.70]

The present author was worried about the lack of knowledge concerning the quality of the kinetic models used in the industry. A model is by definition a small, scaled-down imitation of the real thing. (Men should remember tliis when their mothers-in-law call them model husbands.) In the industry all we require from a kinetic model is that it describe the chemical rate adequately by using traditional mathematical forms (Airhenius law, power law expressions and combinations of these) within the limits of its applications. Neither should it rudely violate the known laws of science. [Pg.117]

One further point is worth mentioning at this time. The definition of a distribution function (3-5) involves the taking of a limit and, consequently, brings up the question of the existence of this limit. The limit will not, in general, exist for all possible time functions X(t), and the investigation of conditions for its existence is a legitimate mathematical problem. However, questions of this sort are quite beside the point in the present context. We are not really interested in knowing how to specify time functions in such a way that their distribution functions exist. Instead, we want to know how to specify a function Fx in such a way that it is the distribution function of... [Pg.105]

Let us first introduce some important definitions with the help of some simple mathematical concepts. Critical aspects of the evolution of a geological system, e.g., the mantle, the ocean, the Phanerozoic clastic sediments,..., can often be adequately described with a limited set of geochemical variables. These variables, which are typically concentrations, concentration ratios and isotope compositions, evolve in response to change in some parameters, such as the volume of continental crust or the release of carbon dioxide in the atmosphere. We assume that one such variable, which we label/ is a function of time and other geochemical parameters. The rate of change in / per unit time can be written... [Pg.344]

Fond et al. [84] developed a numerical procedure to simulate a random distribution of voids in a definite volume. These simulations are limited with respect to a minimum distance between the pores equal to their radius. The detailed mathematical procedure to realize this simulation and to calculate the stress distribution by superposition of mechanical fields is described in [173] for rubber toughened systems and in [84] for macroporous epoxies. A typical result for the simulation of a three-dimensional void distribution is shown in Fig. 40, where a cube is subjected to uniaxial tension. The presence of voids induces stress concentrations which interact and it becomes possible to calculate the appearance of plasticity based on a von Mises stress criterion. [Pg.223]

A descriptive definition of the air factor was presented. No mathematical models were given formulating the relationship between air factor and measurands and no discussion was presented about limitations and assumptions of the method. [Pg.71]

As the definition says, a model is a description of a real phenomenon performed by means of mathematical relationships (Box and Draper, 1987). It follows that a model is not the reality itself it is just a simplified representation of reality. Chemometric models, different from the models developed within other chemical disciplines (such as theoretical chemistry and, more generally, physical chemistry), are characterized by an elevated simplicity grade and, for this reason, their validity is often limited to restricted ranges of the whole experimental domain. [Pg.70]

Can you relate our mathematical definition of approximation to the standard definition of the limit of a function at a point in its domain ... [Pg.110]

For all further questions of definition, mathematical analysis, limits of applicability, and experimental procedure the reader is referred to the specialized literature. The fracture mechanics of polymers are particularly well treated in [25-27]. [Pg.16]

It has been explained that when testing mixture diagrams, factor space is usually a regular simplex with q-vertices in a q-1 dimension space. In such a case, the task of mathematical theory of experiments consists of determining in the given simplex the minimum possible number of points where the design points will be done and based on which coefficients of the polynomial that adequately describes system behavior will be determined. This problem, for the case when there are no limitations on ratios of individual components, as presented in the previous chapter, was solved by Scheffe in 1958 [5], However, a researcher may in practice often be faced with multicomponent mixtures where definite limitations are imposed on ratios of individual components ... [Pg.506]

Although Eq. (1) is a simple mathematical relationship, there are numerous limitations to its appropriate application, based on the assumptions one makes about the pharmacokinetic model to which it is applied. In the case where one assumes instantaneous equilibrium of drug between the tissue and the plasma or blood (i.e., a one-compartment model), the concentration in the sampling compartment is, by definition, proportional to the tissue concentration at all times after dosing, and V determined for any At and Ct pair will be constant Since At at time 0 is the dose (D), it is common to express volume of distribution in a one-compartment model as ... [Pg.182]

The basis functions, in both cases, are complex. This is a known complicating factor in the analysis of non-centrosymmetric crystal structures. In computational chemistry the problem is circumvented by using only real basis functions. The definition and limitation of such functions are discussed in section 2.6.3, but there is a more important mathematical factor that militates against this procedure ... [Pg.240]

Various approaches have been used to define detection limit for the multivariate situation [24], The first definition was developed by Lorber [19]. This multivariate definition is of limited use because it requires concentration knowledge of all analytes and interferences present in calibration samples or spectra of all pure components in the calibration samples. However, the work does introduce the important concept of net analyte signal (NAS) vector for multivariate systems. The NAS representation has been extended to the more usual multivariate situations described in this chapter [25-27], where the NAS is related to the regression vector b in Equation 5.11. Mathematically, b = NAS/ NAS and NAS = 1/ b. Thus, the norm of the NAS vector is the same as the effective sensitivity discussed in Section 5.4.9.1 A simple form of the concentration multivariate limit of detection (LOD) can be expressed as LOD = 3 MINI, where e denotes the vector of instrumental noise values for the m wavelengths. The many proposed practical approaches to multivariate detection limits are succinctly described in the literature [24],... [Pg.134]


See other pages where Mathematical limit definition is mentioned: [Pg.220]    [Pg.109]    [Pg.126]    [Pg.29]    [Pg.29]    [Pg.2354]    [Pg.14]    [Pg.140]    [Pg.686]    [Pg.38]    [Pg.246]    [Pg.446]    [Pg.53]    [Pg.527]    [Pg.66]    [Pg.116]    [Pg.160]    [Pg.21]    [Pg.118]    [Pg.40]    [Pg.256]    [Pg.583]    [Pg.142]    [Pg.349]    [Pg.108]    [Pg.120]    [Pg.13]    [Pg.41]    [Pg.22]    [Pg.241]    [Pg.193]    [Pg.39]    [Pg.14]   
See also in sourсe #XX -- [ Pg.60 ]




SEARCH



Limits definition

© 2024 chempedia.info