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Predictive modelling

Table 1 gives the measured data, estimates of the true values corresponding to the measurements, and deviations of the measured values from model predictions. Figure 1 shows the phase diagram corresponding to these parameters, together with the measured data. [Pg.100]

Fig 5. (a) 60" radial transducer (b) Fluygens model prediction of its acoustic field (c) angular cross section of (b) compared with experimental measurements. [Pg.718]

The central quantity of interest in homogeneous nucleation is the nucleation rate J, which gives the number of droplets nucleated per unit volume per unit time for a given supersaturation. The free energy barrier is the dommant factor in detenuining J J depends on it exponentially. Thus, a small difference in the different model predictions for the barrier can lead to orders of magnitude differences in J. Similarly, experimental measurements of J are sensitive to the purity of the sample and to experimental conditions such as temperature. In modem field theories, J has a general fonu... [Pg.753]

Figure B2.5.7 shows the absorption traces of the methyl radical absorption as a fiinction of tune. At the time resolution considered, the appearance of CFt is practically instantaneous. Subsequently, CFl disappears by recombination (equation B2.5.28). At temperatures below 1500 K, the equilibrium concentration of CFt is negligible compared witli (left-hand trace) the recombination is complete. At temperatures above 1500 K (right-hand trace) the equilibrium concentration of CFt is appreciable, and thus the teclmique allows the detennination of botli the equilibrium constant and the recombination rate [54, M]. This experiment resolved a famous controversy on the temperature dependence of the recombination rate of methyl radicals. Wliile standard RRKM theories [, ] predicted an increase of the high-pressure recombination rate coefficient /r (7) by a factor of 10-30 between 300 K and 1400 K, the statistical-adiabatic-chaunel model predicts a... Figure B2.5.7 shows the absorption traces of the methyl radical absorption as a fiinction of tune. At the time resolution considered, the appearance of CFt is practically instantaneous. Subsequently, CFl disappears by recombination (equation B2.5.28). At temperatures below 1500 K, the equilibrium concentration of CFt is negligible compared witli (left-hand trace) the recombination is complete. At temperatures above 1500 K (right-hand trace) the equilibrium concentration of CFt is appreciable, and thus the teclmique allows the detennination of botli the equilibrium constant and the recombination rate [54, M]. This experiment resolved a famous controversy on the temperature dependence of the recombination rate of methyl radicals. Wliile standard RRKM theories [, ] predicted an increase of the high-pressure recombination rate coefficient /r (7) by a factor of 10-30 between 300 K and 1400 K, the statistical-adiabatic-chaunel model predicts a...
Increased trust in pattern recognition The active user involvement in the data mining process can lead to a deeper understanding of the data and increases the trust in the resulting patterns. In contrast, "black box" systems often lead to a higher uncertainty, because the user usually does not know, in detail, what happened during the data analysis process. This may lead to a more difficult data interpretation and/or model prediction. [Pg.475]

In general, tests have tended to concentrate attention on the ability of a flux model to interpolate through the intermediate pressure range between Knudsen diffusion control and bulk diffusion control. What is also important, but seldom known at present, is whether a model predicts a composition dependence consistent with experiment for the matrix elements in equation (10.2). In multicomponent mixtures an enormous amount of experimental work would be needed to investigate this thoroughly, but it should be possible to supplement a systematic investigation of a flux model applied to binary systems with some limited experiments on particular multicomponent mixtures, as in the work of Hesse and Koder, and Remick and Geankoplia. Interpretation of such tests would be simplest and most direct if they were to be carried out with only small differences in composition between the two sides of the porous medium. Diffusion would then occur in a system of essentially uniform composition, so that flux measurements would provide values for the matrix elements in (10.2) at well-defined compositions. [Pg.101]

In Figure 5.23 the finite element model predictions based on with constraint and unconstrained boundary conditions for the modulus of a glass/epoxy resin composite for various filler volume fractions are shown. [Pg.187]

M.o. theory has had limited success in dealing with electrophilic substitution in the azoles. The performances of 7r-electron densities as indices of reactivity depends very markedly on the assumptions made in calculating them. - Localisation energies have been calculated for pyrazole and pyrazolium, and also an attempt has been made to take into account the electrostatic energy involved in bringing the electrophile up to the point of attack the model predicts correctly the orientation of nitration in pyrazolium. ... [Pg.194]

Even with this modification, we note that the model predicts a drop off in modulus which is steeper than observed in the individual steps. This gradual... [Pg.165]

The more gradual approach to equilibrium than the model predicts can be taken into account by imagining that the rise consists of a series of n smaller (and unresolved) steps. This is equivalent to expanding the model so that it consists of n Voigt elements as shown in Fig. 3.10b. Each of these Voigt elements is characterized by its own value for G, 77, and r. [Pg.172]

An emulsion model that assumes the locus of reaction to be inside the particles and considers the partition of AN between the aqueous and oil phases has been developed (50). The model predicts copolymerization results very well when bulk reactivity ratios of 0.32 and 0.12 for styrene and acrylonitrile, respectively, ate used. [Pg.193]

The prefactor M(T), also called a frequency factor, has units of inverse seconds. It may have a weak dependence on temperature. Some theoretical models predict a variation with, but such variation is frequently ignored and M is taken as constant over limited temperature ranges. The prefactor M is often... [Pg.513]

Figure 6 shows the field dependence of hole mobiUty for TAPC-doped bisphenol A polycarbonate at various temperatures (37). The mobilities decrease with increasing field at low fields. At high fields, a log oc relationship is observed. The experimental results can be reproduced by Monte Carlo simulation, shown by soHd lines in Figure 6. The model predicts that the high field mobiUty follows the following equation (37) where d = a/kT (p is the width of the Gaussian distribution density of states), Z is a parameter that characterizes the degree of positional disorder, E is the electric field, is a prefactor mobihty, and Cis an empirical constant given as 2.9 X lO " (cm/V). ... Figure 6 shows the field dependence of hole mobiUty for TAPC-doped bisphenol A polycarbonate at various temperatures (37). The mobilities decrease with increasing field at low fields. At high fields, a log oc relationship is observed. The experimental results can be reproduced by Monte Carlo simulation, shown by soHd lines in Figure 6. The model predicts that the high field mobiUty follows the following equation (37) where d = a/kT (p is the width of the Gaussian distribution density of states), Z is a parameter that characterizes the degree of positional disorder, E is the electric field, is a prefactor mobihty, and Cis an empirical constant given as 2.9 X lO " (cm/V). ...
C. R. Cutier and R. B. Hawkins, "AppHcation of a Large Model Predictive Controller to a Hydrocracker Second Stage Reactor," Proceedings of... [Pg.80]

Of the models Hsted in Table 1, the Newtonian is the simplest. It fits water, solvents, and many polymer solutions over a wide strain rate range. The plastic or Bingham body model predicts constant plastic viscosity above a yield stress. This model works for a number of dispersions, including some pigment pastes. Yield stress, Tq, and plastic (Bingham) viscosity, = (t — Tq )/7, may be determined from the intercept and the slope beyond the intercept, respectively, of a shear stress vs shear rate plot. [Pg.167]

Spray characteristics are those fluid dynamic parameters that can be observed or measured during Hquid breakup and dispersal. They are used to identify and quantify the features of sprays for the purpose of evaluating atomizer and system performance, for estabHshing practical correlations, and for verifying computer model predictions. Spray characteristics provide information that is of value in understanding the fundamental physical laws that govern Hquid atomization. [Pg.330]

The response produced by Eq. (8-26), c t), can be found by inverting the transfer function, and it is also shown in Fig. 8-21 for a set of model parameters, K, T, and 0, fitted to the data. These parameters are calculated using optimization to minimize the squarea difference between the model predictions and the data, i.e., a least squares approach. Let each measured data point be represented by Cj (measured response), tj (time of measured response),j = 1 to n. Then the least squares problem can be formulated as ... [Pg.724]

Use a decouphng control system d. Use a multivariable control scheme (e.g., model predictive control)... [Pg.737]

Introduction The model-based contfol strategy that has been most widely applied in the process industries is model predictive control (MFC). It is a general method that is especially well-suited for difficult multiinput, multioutput (MIMO) control problems where there are significant interactions between the manipulated inputs and the controlled outputs. Unlike other model-based control strategies, MFC can easily accommodate inequahty constraints on input and output variables such as upper and lower limits or rate-of-change limits. [Pg.739]

Basic Features of MFC Model predictive control strategies have a number of distinguishing features ... [Pg.739]

FIG. 8-44 The moving horizon approach of model predictive control. [Pg.740]

FIG. 14-31 Pressure drop for a valve plate, measured versus model prediction ofBoUes [Chem. Eng. Progr. 72(9), 43 (1976)]. Reproduced with permission of the American Institute of Chemical Engineers. Copyright 1976 AlChE. All rights reserved. [Pg.1378]

The first is the relational model. Examples are hnear (i.e., models linear in the parameters and neural network models). The model output is related to the input and specifications using empirical relations bearing no physical relation to the actual chemical process. These models give trends in the output as the input and specifications change. Actual unit performance and model predictions may not be very close. Relational models are usebil as interpolating tools. [Pg.2555]

A group of measurements are proposed based on preliminary model predictions... [Pg.2564]

Aside from the fundamentals, the principal compromise to the accuracy of extrapolations and interpolations is the interaction of the model parameters with the database parameters (e.g., tray efficiency and phase eqiiilibria). Compromises in the model development due to the uncertainties in the data base will manifest themselves when the model is used to describe other operating conditions. A model with these interactions may describe the operating conditions upon which it is based but be of little value at operating conditions or equipment constraints different from the foundation. Therefore, it is good practice to test any model predictions against measurements at other operating conditions. [Pg.2578]

The statistics literature presents numerous reviews of comparing the description of one model against another. Watanabe and Himmel-blau (1984) present a list of review articles. The judgment criterion is based on a comparison of the model predictions against the measurements. These comparisons are related to the general statistic given below, developed tor each model with its corresponding parameter set. [Pg.2578]

A number of current coupled ocean-atmosphere climate models predict that the overturning of the North Atlantic may decrease somewhat under a future warmer climate.While this is not a feature that coupled models deal with well, its direct impact on the ocean s sequestration of carbon would be to cause a significant decline in the carbon that is stored in the deep water. This is a positive feedback, as oceanic carbon uptake would decline. Flowever, the expansion of area populated by the productive cool water plankton, and the associated decline... [Pg.31]

Once pesticides were identified, monitoring was undertaken by the NRA, where possible, to confirm the usefulness of the model predictions. The most important prediction from the model was that the herbicide bentazone would reach surface waters. Subsequent analysis by the NRA confirmed the detection of bentazone at concentrations above 0.1 /tg D Consequently, the NRA informed... [Pg.54]

The predictions checked in the pilot-plant reactor were reasonable. Later, when the production unit was improved and operators learned how to control the large-scale reactor, performance prediction was also very good. The highest recognition came from production personnel, who believed more in the model than in their instruments. When production performance did not agree with model predictions, they started to check their instruments, rather than questioning the model. [Pg.130]


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See also in sourсe #XX -- [ Pg.288 ]




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Activity prediction models

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Activity prediction models three-dimensional QSAR

Aerosols computational model prediction

An Equilibrium-Based Model for Predicting Potential Ammonia Volatilization from Soil

Animal Models of Disease for Future Toxicity Predictions

Animal Models their Predictive Value

Application of Predictive QSAR Models to Database Mining

Aqueous solubility, predictive model comparisons

Cancer risk assessment predictive modeling

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Case study prediction of permeate flux decay during ultrafiltration performed in pulsating conditions by a hybrid neural model

Case study prediction of permeate flux decay during ultrafiltration performed in pulsating conditions by a neural model

Chemical extraction selective, model predictions

Chemical reaction processes predictive model

Classification models, predictive applications

Comparison of Model Predictions with Experiment

Computational Models for Prediction of Intestinal Permeability

Computational Models for the Prediction of Aerosol Dispersion

Computational model prediction

Computational modeling structure prediction

Computational neural network predictive modeling

Computer model for prediction

Concentration fields, model predictions

Confidence intervals, predictive model

Confidence intervals, predictive model comparisons

Conformations structure prediction models

Controller design model predictive

Cornell model predictions

Correlation coefficient, predictive model

Correlation coefficient, predictive model comparisons

Damping Tube model predictions

Databases predictive models

Design predictive models

Developing models for predicting

Different predictive models

Drug predictive models

Durability life prediction models

Estimating Error Bars on Model Predictions

Experimental Verification of Model Prediction

Explosive Limits Model Predictions

Exposure assessments predictive modeling parameters

Extensional Tube model predictions

Failure prediction model, degradation

Finite-element based life prediction models

Fluid predictive models

French predictive models

From Orbital Models to Accurate Predictions

General kinetic model and prediction of critical effects

HETP Prediction—Mass Transfer Models

Healy-James model predictions

High Effectiveness of an HCA Cell Model in Predictive Toxicology

Homology modeling sequence-structure-function prediction

Homology modeling structure prediction

In Silico Methods for Prediction of Phototoxicity - (Q)SAR Models

Knowledge-based prediction computational models

Knowledge-based prediction protein modeling

Life Prediction Model

Lifetime prediction kinetic model

Liquid residence-time predictions model

Local composition model activity coefficient prediction

Machine Learning Models for Predictive Studies

Mathematical model conversion predicted

Mathematical modeling predicting efficacy

Mathematical modeling predicting toxicity

Mathematical models predictions

Mental Models and Predictive Behaviour

Mesoscale models prediction combination

Model Predicting Energy Requirement and Product Size Distribution

Model Predictions for Void Growth

Model Predictive Control of Batch Processes (SHMPC)

Model Predictive Heuristic Control

Model acceptance criteria for the time-domain technique predictability

Model acceptance for transfer-function-based technique predictability

Model data, predictions

Model flow pattern prediction method

Model predictability

Model predictions and experimental data

Model predictions and measured

Model predictive control

Model predictive control (MPC

Model predictive control advantages

Model predictive control algorithms

Model predictive control constraints

Model predictive control controller

Model predictive control description

Model predictive control disadvantages

Model predictive control dynamic programming

Model predictive control enhancements

Model predictive control history

Model predictive control integrators

Model predictive control moving horizon

Model predictive control nonlinearity

Model predictive control prediction horizon

Model predictive control standard quadratic programming

Model predictive control step-response

Model predictive control tuning parameters

Model predictive performance

Model-Predictive Control of Continuous Processes

Model-free predictions

Modeling Predictions

Modeling Predictions

Modeling and Life Prediction

Modeling and Prediction of Solid Solubility by GE Models

Modeling and prediction

Modeling approaches final failure prediction

Modeling forward-predictive

Modeling life prediction model

Modeling models, setting-specific Predictive

Modeling of Chain Dynamics and Predictions for NMR Measurands

Modeling predictive simulations

Models for Predicting Battery Behavior

Models for Prediction of Absorption

Models for Prediction of Incipient Boiling Heat Flux and Wall Superheat

Models for Prediction of Volume

Models for performance prediction

Models for predicting functions

Models predictivity range

Models, predictions based

Molecular conformation, prediction through models

Molecular modeling ADME prediction

Molecular modeling protein structure prediction

Multiple linear regression model prediction

Multivariate calibration models prediction

NEWS-model-predictions

Nonlinear model predictive control

Nonlinear model predictive controller

Operator exposure models, predicted

Oscillation Model predictive equations

Oscillation Model predicts

Other prediction models of asphalt stiffness

Oxidation computer model prediction

Partial least squares models prediction

Pharmacokinetics predictive models

Phosphorus predictive modeling

Photobioreactor predictive models

Polarization model-predicted

Polymer systems, predictive aging models

Predictability of Process Models

Predicted results of the composite model and comparison with experiments

Predicting Fiber Orientation — The Folgar-Tucker Model

Predicting Reactor Behavior with the Macrofluid Model

Predicting the Striation Thickness in a Couette Flow System - Shear Thinning Model

Prediction and Extrapolation in the Simple Linear Model

Prediction error model

Prediction from Scale Model

Prediction model

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Prediction models polymer systems

Prediction of Plasma and Tissue Concentration-Time Profiles by Using the PBPK Modeling Approach

Prediction of diffusion coefficients in gases, liquids, amorphous solids and plastic materials using an uniform model

Prediction of model uncertainty

Prediction sinusoidal models techniques

Prediction techniques Modeller tool

Prediction techniques comparative modeling methods

Prediction techniques computational models

Prediction techniques free energy modeling

Prediction techniques potential energy models

Prediction techniques protein modeling

Prediction techniques solvation energy models

Predictions from Model Ecosystem (Microcosm and Mesocosm) Data

Predictions from the Pariser-Parr-Pople-Peierls model

Predictions of Physical Properties with the Two Models

Predictions, cellular metabolic modeling

Predictive Accuracies of Models

Predictive Chemical Kinetic Models

Predictive CoMFA models

Predictive Defluidization Models and Operability Maps

Predictive Model Markup Language

Predictive Modeling Approaches for Assessing Human Lead Exposure

Predictive Modeling and Rational Catalyst Design

Predictive Modeling in Heterogeneous Catalysis

Predictive Modeling of the Continuous Catalyst Regeneration (CCR) Reforming Process

Predictive Modelling of Aluminium Fluoride Surfaces

Predictive Models from Pharmacological Data

Predictive QSAR Models as Virtual Screening Tools

Predictive QSAR models

Predictive QSAR models model validation

Predictive QSAR models modeling workflow

Predictive activity coefficient models

Predictive exposure models

Predictive in-silico models

Predictive kinetics chemical kinetic models

Predictive material models

Predictive model fuel evaporation

Predictive modeling

Predictive modeling reforming process

Predictive modeling technique

Predictive modeling/control

Predictive modelling calculations

Predictive models

Predictive models

Predictive models applicability

Predictive models environmental variables

Predictive models error analysis

Predictive models molecular descriptors

Predictive models performance evaluation

Predictive models random forest model example

Predictive models, drug-likeness

Predictive of a model

Predictive value model

Predictive value, CoMFA models

Quantitative structure-activity relationships predictive models

Reactivity prediction models

Resampling Methods for Prediction Error Assessment and Model Selection

Response predicted by the model

Reynolds number model predictions comparison

Selection of the Predictive Model Class

Shear Tube model predictions

Simple Predictive Models

Skill 1.3c-Predict molecular geometries using Lewis dot structures and hybridized atomic orbitals, e.g., valence shell electron pair repulsion model (VSEPR)

Solubility predictions, model

Solvation energy models structure prediction

Spectrum prediction empirical modeling methods

Stem Cell-Based Predictive Models

Stochastic model predictive control

Structure prediction techniques computational models

Structure prediction techniques free energy modeling

Structure prediction techniques potential energy models

The Predictive Model

The Predictive Model A Multistage Stochastic Approach

Thermodynamic Models for the Prediction of Petroleum-Fluid Phase Behaviour

Thermoset resin processing predictive models

Time series modeling prediction error method

Tools for Predictions and Modeling

Transition prediction model

Tutorial Developing Models for Solubility Prediction with 18 Topological Descriptors

Two-phase model predictions and experimental observations

UK Predictive Operator Exposure Model

Variable selection and modeling method based on the prediction

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