Parameter required

In many process-design calculations it is not necessary to fit the data to within the experimental uncertainty. Here, economics dictates that a minimum number of adjustable parameters be fitted to scarce data with the best accuracy possible. This compromise between "goodness of fit" and number of parameters requires some method of discriminating between models. One way is to compare the uncertainties in the calculated parameters. An alternative method consists of examination of the residuals for trends and excessive errors when plotted versus other system variables (Draper and Smith, 1966). A more useful quantity for comparison is obtained from the sum of the weighted squared residuals given by Equation (1). [Pg.107]

Pure-component parameters required in Equations (16) through (23) are... [Pg.132]

Subroutine PRDTA2. This subroutine reads the pure-component and binary parameters required for the various correlations describing the liquid and vapor phases. All input parameters are printed for verification. [Pg.217]

Oil viscosity is an important parameter required in predicting the fluid flow, both in the reservoir and in surface facilities, since the viscosity is a determinant of the velocity with which the fluid will flow under a given pressure drop. Oil viscosity is significantly greater than that of gas (typically 0.2 to 50 cP compared to 0.01 to 0.05 cP under reservoir conditions). [Pg.109]

Figure 5 shows the display in the measure mode. It consists of a detailed A-scan window and a number of smaller windows for display parameters and inspection parameters. The A-scan display may be used as a stand-alone tool or as a tool for measuring parameters required for a specific inspection, e.g. probe parameters, reference echoes, and depth compensation with automatic transfer to the data set. [Pg.786]

The developers of ZINDO found that the parameters required to reproduce orbital energy orderings and UV spectra are different from those required to reproduce accurate structures by geometry optimization. They introduced anew pair of parameters, called the overlap weighting factors, to account for this. These parameters are provided in HyperChem in the Semi-empirical Options dialog box. Their effect is to modify the resonance integrals for the off-diagonal elements of the Fock matrix. [Pg.295]

Once the 3D strucmre of a molecule and all the parameters required for the atomic and molecular connectivities are known, the energy of the system can be calculated via Eqs. (l)-(3). First derivatives of the energy with respect to position allow for determination of the forces acting on the atoms, information that is used in the energy minimization (see Chapter 4) or MD simulations (see Chapter 3). Second derivatives of the energy with respect to position can be used to calculate force constants acting on atoms, allowing the determination of vibrational spectra via nonnal mode analysis (see Chapter 8). [Pg.11]

The question of the actual form of the relation between toughness and crack speed is still rather unclear. It is tempting to relate 4> V) to the imaginary part of the elastic modulus, but the size parameter required to relate V to a time or... [Pg.239]

By computing values from the above equations, a curve of T versus time may be plotted. This information may be used to design heating systems or evaluate the performance of existing ones. The input parameters required for the analysis are T, U, A, W, Cp, and T,. [Pg.520]

Change in the PSM rule includes all modifications to equipment, procedures, raw materials, and processing conditions other than replacement in kind. These changes are managed by identification and review prior to implementation. For example, any operation outside of the operating procedures parameters requires review and approval by a written management of change. [Pg.73]

The equipment of a processing system is designed according to process conditions witli a view to containing tlie chemical(s) and maintaining the control parameters required to produce tlie desired product. Equipment failure can generally be attributed to one or more of tlie following hazards ... [Pg.462]

Deriving such heat of formation parameters requires a large body of experimental Ai/f values. For many classes of compound there are not sufficient data available. Only a few force fields, notably MM2 and MM3, attempt to parameterize also heats of formation. Most force fields are only concerned with reproducing geometries and possibly conformational relative energies, for which the steric energy is sufficient. [Pg.29]

The QA method uses only one shift parameter, requiring that Ats = —A, and restricts the total step length to the trust radius (compare with eq. (14.9)). [Pg.334]

The determination of reaction orders and of activation parameters requires accurate measurements of the concentrations of the different species present in the reaction medium. [Pg.56]

Reactions between solids. Parameters requiring consideration in the description of any reaction mixture and in the measurement of interaction kinetics... [Pg.249]

The experimental realization of the optimal initial states is however a completely uncharted area at this time. In an earlier paper (17), we have presented the formulae to obtain field parameters required to achieve these field optimized initial states and the optimal control (30) approach may also be easily and profitably employed to attain this FOIST comprising of only three... [Pg.276]

A general method has been developed for the estimation of model parameters from experimental observations when the model relating the parameters and input variables to the output responses is a Monte Carlo simulation. The method provides point estimates as well as joint probability regions of the parameters. In comparison to methods based on analytical models, this approach can prove to be more flexible and gives the investigator a more quantitative insight into the effects of parameter values on the model. The parameter estimation technique has been applied to three examples in polymer science, all of which concern sequence distributions in polymer chains. The first is the estimation of binary reactivity ratios for the terminal or Mayo-Lewis copolymerization model from both composition and sequence distribution data. Next a procedure for discriminating between the penultimate and the terminal copolymerization models on the basis of sequence distribution data is described. Finally, the estimation of a parameter required to model the epimerization of isotactic polystyrene is discussed. [Pg.282]

The estimation of the two parameters requires not only conversion and head space composition data but also physical properties of the monomers, e.g. reactivity ratios, vapor pressure equation, liquid phase activity coefficients and vapor phase fugacity coefficients. [Pg.299]

M. van Noordwijk and S. C. van de Geijn, Root, shoot and soil parameters required for proeess-oriented models of crop growth limited by water or nutrients. Plant Soil I8S (1996). [Pg.371]

Work with those who submit samples to limit submissions to those likely to yield useful information. In a typical sample queue, some are outside of the parameters required for a standardized assay, having a concentration too low for the precision required or containing matrix components incompatible with the assay. Others may be low on the list of project priorities. Analytical morale gains if every sample run leads to results that are valued. [Pg.39]

A method was also developed to predict the parameters required for the NRTL equation the ASOG method, Kojima and Tochigi (1979). [Pg.347]

There is no doubt that this result is correct, as a close examination of their derivation would suggest. Interestingly enough, the results of all reduce properly to this result in the one-dimensional case, although there are disagreements in the TV-dimensional case, (Note We use the symbol K to represent a count of the parameters which fix a matrix. A first subscript, C or R, is attached to indicate whether the matrix is complex or real, and a second subscript, C or R, is attached to indicate whether the parameters counted are complex or real. For example, KCR signifies the number of real parameters required to fix a complex matrix.)... [Pg.140]

However, to determine the number of real pieces of information required to fix the projection from an M-dimensional space onto an /V-dimensional subspace spanned, not by the particular (occupied) basis in which P is diagonal, but by any basis of the subspace, it is necessary to subtract the numberof real parameters required to fix a particular basis in the /V-dimensional subspace from the total Kcy, such a number corresponds to the N2 real conditions that are necessary to fix a unitary transformation [11] in the subspace. But, as the phases ofthe eigenstates, < , are arbitrary as far as the physical state is concerned [4, 12], this latter number is reduced by N, the number of eigenstates belonging to the projection space. Hence, the number of independent real parameters in the unitary transformation which fixes the basis spanning the... [Pg.144]

Currently, there are many databases where the physicochemical, toxicological parameters required to perform a risk assessment can be obtained. It must be borne in mind that the existence of a quality control parameters included in the databases is of great importance. This quality control can be accomplished through periodic updating of the database, the inclusion of bibliographical references of the origin of each parameter, peer reviewed bibliography, etc. [Pg.104]

The updating function for the run database is another editing program that is used to create an entry in the run database for each data collection task in a batch. The run database entry contains optional descriptive information as well as the parameters required to drive the task. The user edits the parameter values to suit his needs for the tasks to be performed. Parameters in the run database are validated before the run entry is made permanent. [Pg.145]

Refiners are obliged to comply with the specifications fixed by the government environmental agencies [41] and with the performance parameters required by the final users market. In Table 5, a comparison of the evolution of the regulated fuel specifications in US and Europe [42] is presented. [Pg.24]

Minimum Duct Velocity. Once the types and locations of hoods, enclosures and booths have been established and the exhaust rates determined, it is necessary to design the ductwork to transfer the contaminated gas to the collection or cleaning device. An essential parameter required for this purpose is the minimum duct or conveying velocity, Vfmm, which is required to ... [Pg.756]

This is the essence of AC impedance techniques the cell is replaced by a suitable model system, in which the properties of the interface and the electrolyte are represented by appropriate electrical analogues and the impedance of the cell is then measured over as wide a frequency range as possible. By comparing the measured results with values calculated from the model system, we can evaluate both the suitability of our model and the values of the parameters required. [Pg.162]

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