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Mathematically complete model

In this section, a mathematical model is introduced which fulfills these requirements. First, the complete model equations are given and their derivation is briefly indicated. In the second part, an accompanying diagram to this model is introduced, in which the simulation results can be displayed. [Pg.50]

Computer simulation models have been formulated for cascade and Stratco sulfuric acid alkylation units. These complete models incorporate mathematical descriptions of all the interacting parts of the units, including reactors, distillation columns, compressors, condensers, and heat exchangers. Examples illus-strate diverse model applications. These Include identifying profitable unit modifications, comparing cascade to Stratco performance, evaluating optimal unit capacity and determining optimal deisobutanizer operation. [Pg.270]

The general mathematical process model has to be completed with the models for the recycled suspension reservoir and for the pump. The suspension reservoir is a classical perfect mixing unit (see Fig. 3.8) so its model includes the unsteady total and solid balances. These balances are given below by relations (3.37) and (3.38). After Fig. 3.8, the mathematical model of the pump gives the relationship between the pump exit flow rate and its pressure (relation (3.39)) ... [Pg.54]

The mathematical structure of the models is their unifying background systems of nonlinear coupled differential equations with eventually nonlocal terms. Approximate analytic solutions have been calculated for linearized or reduced models, and their asymptotic behaviors have been determined, while various numerical simulations have been performed for the complete models. The structure of the fixed points and their values and stability have been analyzed, and some preliminary correspondence between fixed points and morphological classes of galaxies is evident—for example, the parallelism between low and high gas content with elliptical and spiral galaxies, respectively. [Pg.505]

Numerical Solvers The mathematical process models of a unit operation or a complete plant are large and highly non-linear. As analytical solutions are impossible, iterative, numerical approaches are used to solve the equations. [Pg.378]

Based on analysis of equations (2.1)-(2.4) of the complete mathematical model, it can be confirmed that some of the parameters of the YSZ-basedgas sensors (initial concentration of the charge carriers, concentration of the measuring gas, working temperature, etc.) are included directly into the system of equation (2.1). Other parameters, for example, thickness of the SE, are included into th boundary conditions (2.3) or (2.4). In this case, some of the functions (/i, /2, f/o (jf)), characterizing the interactions of the measuring environment with the SE (RE) of the sensor, must be taken into consideration at determination of the elementary and boundary conditions for the complete model (2.1)-(2.4). [Pg.47]

Compared with the derivations described so far, models with more than one layer require mathematically completely different approaches. The respective systems of differential equations either have to be solved numerically (Smith, 1965 Lasia, 1983 Bergel and Comtat, 1984) or a new approach must be found. The mathematical problem is that the boundary conditions are not known for each layer. For the interfaces between the different membranes only mass conservation relations are known rather than boundary values and no-flux conditions. They may be written ... [Pg.81]

In designing a mathematical simulation of any physical or chemical process, one must first determine an adequate geometric representation of the actual process. The success of the overall simulation depends often upon this initial step in the complete modeling process. When the physical or chemical process that is to be modeled is part of a physiologically and anatomically complex organ of the human body, the determination of a... [Pg.139]

The mathematical modeling of liquid membrane separations Is essential to accurate prediction and scale-up of these systems. Also, accurate and complete models Identify the Important physical properties and operating conditions. Models can be used to Identify and guide the pertinent experimental program which should be followed. [Pg.12]

However, already in 1930s deviations were observed between the results of precision spectroscopy and the Dirac theory for simple atomic systems, primarily for the hydrogen atom. The existence of negative-energy states in the solutions of Dirac equation is the mathematical but not the physical grounds of the existence of particles and antiparticles (electrons and positrons). Besides, the velocity of light is finite. For an complete model we must turn to quantum field theory and quantum electrodynamics (QED) [4]. [Pg.2]

The theoretical modeling of the vibrations of molecular chains with finite length has been nicely treated by Zbinden [18] and by Snyder and Schachschneider [9, 34]. While the approach by Zbinden is mathematically complete, but it applies to simplified monoatomic chains, quite away from chemical reality, the model by Snyder and Schachschneider is more directly applicable to real molecules and will be... [Pg.124]

In 1907, Milner [8] first suggested that the variation of surface tension of a surfactant solution could be mediated by molecules diffusing to the interface. Some considerable time later, Langmuir and Schaeffer [9] made a significant advance when they looked at the diffusion of ions into monolayers and proposed a mathematical model of the diffusion process. However, it was not until the seminal 1946 paper of Ward and Tordai [10] that the first complete model for diffusion-based kinetics emerged. The Ward-Tordai model accounts for three variables the bulk concentration, the subsurface concentration, and the surface tension. This led to the celebrated Ward-Tordai equation ... [Pg.409]

For the modeled function, it exists a mathematical function to compute the states and probability to be at each state, this is relative to Multi-State System theory (Lisnianski Levitin 2003). A node characterized by its mathematical function models resource assembly to complete modeled function. As in Fault-Tree, nodes like AND, OR and K/N can be expressed, as well as more specific nodes, directly related to a function. [Pg.956]

Formulation of a mathematical programming model to identify the optimal set of MKPIs among those assigned that represents the best compromise between the conciseness and the completeness of the returned information. [Pg.1111]

The relationship between these parameters (and other parameters such as space velocity, inert level, concentrations and temperatures at various points in the synthesis loop, etc.) may be described in mathematical models which can be used for design, simulation, and optimization. The models must contain procedures to calculate the performance of each of the elements in the synthesis loop (at least synthesis reactor and separator, and for complete models also the compressor and recirculator, the heat exchangers, etc.) as well as procedures to describe the sequence of operations and the interaction between them. Descriptions of loop models are given in [453-458] complete mass - and energy... [Pg.225]

The Supplement B (reference) contains a description of the process to render an automatic construction of mathematical models with the application of electronic computer. The research work of the Institute of the applied mathematics of The Academy of Sciences ( Ukraine) was assumed as a basis for the Supplement. The prepared mathematical model provides the possibility to spare strength and to save money, usually spent for the development of the mathematical models of each separate enterprise. The model provides the possibility to execute the works standard forms and records for the non-destructive inspection in complete correspondence with the requirements of the Standard. [Pg.26]

One of the most commonly used constructs is a model. A model is a simple way of describing and predicting scientific results, which is known to be an incorrect or incomplete description. Models might be simple mathematical descriptions or completely nonmathematical. Models are very useful because they allow us to predict and understand phenomena without the work of performing the complex mathematical manipulations dictated by a rigorous theory. Experienced researchers continue to use models that were taught to them in high school and freshmen chemistry courses. However, they also realize that there will always be exceptions to the rules of these models. [Pg.2]


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