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Selection of appropriate

The described method can generate a first-order backward or a first-order forward difference scheme depending whether 0 = 0 or 0 = 1 is used. For 9 = 0.5, the method yields a second order accurate central difference scheme, however, other considerations such as the stability of numerical calculations should be taken into account. Stability analysis for this class of time stepping methods can only be carried out for simple cases where the coefficient matrix in Equation (2.106) is symmetric and positive-definite (i.e. self-adjoint problems Zienkiewicz and Taylor, 1994). Obviously, this will not be the case in most types of engineering flow problems. In practice, therefore, selection of appropriate values of 6 and time increment At is usually based on trial and error. Factors such as the nature of non-linearity of physical parameters and the type of elements used in the spatial discretization usually influence the selection of the values of 0 and At in a problem. [Pg.66]

In this experiment students standardize a solution of HGl by titration using several different indicators to signal the titration s end point. A statistical analysis of the data using f-tests and F-tests allows students to compare results obtained using the same indicator, with results obtained using different indicators. The results of this experiment can be used later when discussing the selection of appropriate indicators. [Pg.97]

By selection of appropriate operating conditions, the proportion of coproduced methanol and dimethyl ether can be varied over a wide range. The process is attractive as a method to enhance production of Hquid fuel from CO-rich synthesis gas. Dimethyl ether potentially can be used as a starting material for oxygenated hydrocarbons such as methyl acetate and higher ethers suitable for use in reformulated gasoline. Also, dimethyl ether is an intermediate in the Mobil MTG process for production of gasoline from methanol. [Pg.165]

Compounding. Owing to the number of ingredients required in a conventional mbber recipe, fluorocarbon elastomer compounding seems simple compared to typical hydrocarbon elastomer recipes. However, the apparent simplicity of such formulations makes a selection of appropriate... [Pg.511]

Selection of appropriate time intei vals for increment extractions relates to property variation (inhomogeneity) within material flow streams. Ten minute extraction intei vals are generally adequate to obtain suitably representative samples from material flows under practical circumstances. Precise determination of extraction intei vals consistent with individual apphcations can be calculatedthrough autocorrelation of historical sampling data, a statistical method described in references (Gy, Pitard). [Pg.1760]

To gather information which will enable selection of appropriate control equipment. If a source test determines that the emission is 3000 mg of particulate per cubic meter and that it has a weight mean size of 5 p.m, a control device must be chosen which will collect enough particulate to meet some required standard, such as 200 mg per cubic meter. (4) To determine the efficiency of control equipment installed to reduce emissions. If a manufacturer supplies a device guaranteed to be 95% efficient for removal of particulate with a weight mean size of 5 /rm, the effluent stream must be sampled at the inlet and outlet of the device to determine if the guarantee has been met. [Pg.534]

Selection of appropriate disposal routes for liquids/solids to comply with acceptable discharge levels Disposal of toxic waste... [Pg.417]

The kind of convective heat transfer—forced convection or natural (at floor, wall, or ceiling)—must be considered and taken into account by selecting appropriate values for the convective heat transfer coefficient see Eq. (11.14)). Thus, the heat transfer coefficient implicitly assumes the flow situation at the surface. Normally, coefficients for convective heat transfer are considered as a preset constant parameter (the coefficient may be defined as variable, however, depending on other parameters). Therefore, the selection of appropriate values is crucial. Values for heat transfer coefficients can be found in several references a comprehensive summary is given in Daskalaki. ... [Pg.1063]

The TA methods described so far can be evaluated in terms of their focus on different aspects of the human-machine interaction. To facilitate the process of selection of appropriate TA methods for particular applications. Figure 4.14 describes ten criteria for evaluation. These criteria are in terms of the usability of the methods for the following applications ... [Pg.187]

Nonetheless, these results are partial and can be seen only as a test study, and clearly many improvements will be considered. For example, the decision at each node should not be restricted to the only use of molecular key attributes, but should also take into account the mobile phase constituents. Future works will also extend this approach to the full database and will probably lead to the introduction of knowledge rules in CHIRBASE. Knowledge rules will help the users not only in the choice of a wide range of columns but also in the selection of appropriate experimental conditions. [Pg.122]

For any boiler plant under consideration, the selection of appropriate programs and the application and control methods employed should be consistent with these objectives. [Pg.142]

Second, it is necessary to take account of non-Newtonian behaviour in the design of process plant and pipelines. Heat and mass transfer coefficients are considerably affected by the behaviour of the fluid, and special attention must be devoted to the selection of appropriate mixing equipment and pumps. [Pg.105]

The carbohydrate has sites for ionic interaction (clusters of sialic acid or sulphate residues) and also hydrophobic interaction (clusters of hydrophobic methyl groups offered by fucose residues). Sedimentation velocity has been a valuable tool in the selection of appropriate mucoadhesives and in the characterisation of the complexes [ 138-143]. [Pg.244]

The selection of appropriate polymeric bromine reagent according to the polymeric structure (step of crosslinking, porosity, step of dilution with styrene, granulation, type of heterocyclic ring incorporated, numbers of N) is very important. From production point of view the use of polymeric reagents reduces the costs for solvents and working hours. [Pg.85]

There are some aspects of process design in which decisions are based primarily on past experience rather than on quantitative performance models. Problems of this type include the selection of constraction materials, the selection of appropriate models for evaluating the physical properties of homogeneous and heterogeneous mixtures of components, and the selection of safety systems. Advances in expert systems technology and information management will have a profound impact on expressing the solutions to these problems. [Pg.158]

In conventional closed-form analysis, one generally seeks to simplify the governing equations by dropping those terms which are zero or whose numerical magnitudes are small relative to the others, and then proceeding with a mathematical solution. In contrast, our code is written to contain all of the terms (except uVu, for now), and the particularization to specific problems is done entirely by the selection of appropriate numerical parameters in the input dataset. [Pg.271]

Determination of appropriate measuring and analysis methods. Decisions must be made on the selection of appropriate and available measuring and or analytical equipment and tools. The characteristics of the methods must be discussed in terms of specificity, accuracy, precision, sensitivity of the methods, and locations of measuring and/or sampling (off-line, at-line, on-line, in-line, non-invasive). [Pg.561]

Several aspects should be considered in the selection of appropriate Pt precursors. Solubility of precursor is important as this parameter determines how well a precursor can be dissolved in a given solvent so as to facilitate the nucleation and growth. Reduction potential is another parameter, which governs the ease with which the precursor can be reduced to Pt metal. Finally, the thermal stability of the precursor partly determines the reaction temperature for the formation of Pt nanoparticles. [Pg.310]

Selection of appropriate pharmacotherapy is dependent upon distinguishing, identifying, and understanding different seizure types. [Pg.443]

O Accurate diagnosis and classification of urinary incontinence type is critical to the selection of appropriate drug therapy. [Pg.803]


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