Optimisation Approaches

These kinds of maps and optimisation approaches represent impressive applications of the quantitative revolution to purposes in materials engineering. 

Balakrisliiia, S. and Biegler, L.T., 1996. Chemical reactor network targeting and integration An optimisation approach. In Admnces in Chemical Engineering. Ed. J.L. Anderson, 23, 243. 

B. S. Iversen, A. Panayi, J. P. Camblor and E. Sabbioni, Simultaneous determination of cobalt and manganese in urine by electrothermal atomic absorption specttrometry. Method development using a simplex optimisation approach, J. Anal. At. Spectrom., 11(8), 1996, 591-594. 

Ronzoni, S., Peretto, I., Giardina, G.A.M. Lead generation and lead optimisation approaches in the discovery of selective, non-peptide ORL-1 receptor agonists and antagonists, Exp. Opin. Ther. Patents 2001, 11, 525-546. 

Thus, in this type of technical-economical optimisation approach it is possible to express the storage requirements in two complementary manners ... 

Plastria F (2001) Static competitive facility location An overview of optimisation approaches. European Journal of Operational Research 129 461-471... 

An optimised approach to (15,2/ )-monoacetate, consisting of the addition of PPL to a solution of the diol in dry EtOAc, resulted in excellent >99% ee acetylation, but with only 88% conversion [83]. 

Predicting structures of compounds in the solid state by the global optimisation approach... 

Precise and rugged quantitative analysis generally requires that be greater than 1.5. Further, the time of analysis should be short (preferably within 5-10 min) and the consumption of the mobile phase per run should be minimal, such as in the example in Fig. 1.18A. This is rarely obtained in the first one or two runs with a new sample. However, the results of the initial test runs can provide useful information for improving the separation either empirically or by using a computer-assisted optimisation approach. 

The above two optimisation approaches have different effects on the cost of preparative chromatography. Especially, if efficiency is increased by decreasing the particle... 

Table 4.2 elucidates the quantitative results of these calculations. The cost efficiency approach leads to an emission reduction for the sectors covered by emissions trading, which for the period 2005-2007 is about 36 Mt CO2 below the average emissions during the 2000-2002 base period. For the period 2008-2012, the model even produced an emission reduction of 86 Mt CO2 compared with the base period levels. The prominent role of input data, as well as the specific problems of the optimisation approach of the energy system model which was deployed, is above all apparent in the target value for the transportation sector. Here, the measures to reduce emissions are not cost-efficient from the perspective of the macroeconomic optimisation approach. 

An efficient and robust optimisation algorithm is primordial for this solution strategy. Rao Sawyer (1995) applied Powell s method to tackle the optimisation. Koyliioglu et al. (1995) defined a linear programming solution for this purpose. The input interval vector defines the number of constraints and, therefore, strongly influences the performance of the procedure. Also, because of the required execution of the deterministic FE analysis in each goal function evaluation, the optimisation approach is numerically expensive. Therefore, this approach is best suited for rather small FE models with a limited number of input uncertainties, unless approximate methods can be used that avoid the expensive iterative calculation of the entire FE system of equations. 

Thus, the three step algorithm results in a hybrid procedure in the first step, the /hi)-domain is approximated using a global optimisation approach in the second and third step, the modal and total envelope FRFs are calculated using interval arithmetic. 

The main advantage of the evolutionary optimisation approach lies in the capability to handle systems with many compensators, especially distributed dampers (Fu and Johnson 2009). In such cases, conventional methods are difficult to apply and tend to find only local maxima of the objective function. 

A Two-stage Optimisation Approach to the Design of Water-using Systems in Process Plants... 

Vu, T.T.L. and Schneider, P.A., 2002, Improving the Control of an Industrial Sugar Crystalliser a Dynamic Optimisation Approach, Computer Aided Chemical Engineering 10 (ESCAPE-12), Elsevier, Amsterdam. 

In this paper an industrial semibatch polymerisation process is considered. In order to guarantee the product quality particularly controlled reaction conditions are necessary. The general aim of this work is to ascertain optimal state and control profiles and to develop a model-based control scheme. As a first step, this paper introduces the dynamic model, which is validated with experimental data, and describes the optimisation approach. An aim of the work is to assess the possibilities of the commercial flowsheet simulator CHEMCAD in the optimisation of the performance of semibatch polymerisation processes. Finally the formulation of the mathematical optimisation problem, solution strategies and their implementation in CHEMCAD are discussed. 

A mathematical optimisation approach is now being implemented to determine optimal operating policies. Future work will deal with the implementation of the optimal trajectories considering disturbances of the process and on-line optimisation as well. 

The different optimisation approaches are compared in terms of optimal control variables (figure 4) and in terms of criteria (table 3). Propylene glycol synthesis involves three control variables reactants introduction, heat transfer fluid temperature, reflux policy. Whatever the optimisation approach is, a batch profile always constitutes the optimal solution of reactants introduction. Hence, the comparison of control variables is reduced to the comparison of temperature and reflux policy. 

Table 4 Comparison of operating times according to the optimisation approach.

Environmental Impact Minimisation through Material Substitution A Multi-Objective Optimisation Approach... 

Numerical optimisation approaches have been traditionally used in design of selective excitation and inversion pulses. This usually involved a variation of a small number of parameters that describe a subset of pulse shapes. Kobzar et al proposed to apply the optimal control theory to remove the restriction of the predetermined pulse shape and to obtain a general solution that meets the criteria of maximum rf-amplitude, maximum pulse duration, temporal digitisation of the pulse and compensations for Bi-field inhomogeneity. The application of the method allowed to improve most of the published selective pulses. The method was extended further to optimise coherence transfer steps in coupled spin systems.The reported optimised propagators maximised the... 

Simultaneous determination of Co and Mn in urine by electrothermal atomic absorption spectrometry. Method development using a simplex optimisation approach. 

---