Energy/yield optimisation

On the other hand, the system shown on the right side is quite different. Beginning with input of relatively small amounts of energy, the particle size distribution does not improve but constantly decreases, showing heavily heteroflocculation in the microscopic picture. Again variation and optimisation of the emulsifiers system yielded a sample that showed nearly spontaneous distribution of the organic phase and resistance to shear induced destruction of the formulation. 

To optimise the geometry, the energy must be expressed as a function of atomic displacements. This yields the partial derivatives crucial to automatic minimisation algorithms. The expressions for the total energy derivatives with respect to atomic displacements are quite complex for ab initio and semi-empirical methods but trivial for empirical schemes like Molecular Mechanics (MM). Virtually all modern computer codes provide extensive, efficient facilities for determining ground state molecular geometries. 

Optimisation is an advanced feature in flowsheeting. The first step is the formulation of an objective function, which may be of technical or economic nature. In the first category we may cite the yield of transformation of raw materials in products, the energy consumed or saved in a process, the amount of emissions or impurities, etc. An economic function can be the total operation cost, the profit, or a measure of profitability, as the rate of return on investment (see Chapter 15). 

In the optimisation of every class of luminescent materials, it is crucial to have quantitative data on the luminescence brightness of each member of the class. This quantitative brightness, in molecular terms, is the product of the extinctimi coefficient and the overall luminescence quantum yield (see Chap. 2). More detailed information on the photophysical performance of luminescent lanthanide complexes may be obtained by dissecting this brightness into the individual contributions of extinction coefficient, energy transfer efficiency and intrinsic lanthanide luminescence yield. 

The nuclear reaction cross section data are needed in radioisotope production programs mainly for optimisation of production routes, i.e., to maximize the yield of the desired product and to minimize the yields of the radioactive impurities. From a given excitation function, the expected yield of a product for a certain energy range, i.e., target thickness, can be calculated using the expression ... 

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