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Primary process final, definition

The quantitative assessment of photochemical activity is facilitated by introducing the quantum yield. In the practice of photochemistry a variety of quantum yield definitions are in use depending on the type of application. There are quantum yields for fluorescence, primary processes, and final products, among others. In atmospheric reaction models, the primary and secondary reactions usually are written down separately, so that the primary quantum yields become the most important parameters, and only these will be considered here. Referring to Table 2-4, it is evident that an individual quantum yield must be assigned to each of the primary reactions shown. The quantum yield for the formation of the product Pf in the ith primary process is the rate at which this process occurs in a given volume element divided by the rate of photon absorption within the same volume element. [Pg.60]

The Gas Directive defines upstream pipelines as those which are part of a production project or which are used to convey natural gas from one or more such projects to a processing plant or terminal or final coastal landing terminal (Art. 2 No. 2). A primary question is if all Norwegian offshore pipelines are covered by this definition. [Pg.314]

This chapter introduces the reader to elementary concepts of modeling, generic formulations for nonlinear and mixed integer optimization models, and provides some illustrative applications. Section 1.1 presents the definition and key elements of mathematical models and discusses the characteristics of optimization models. Section 1.2 outlines the mathematical structure of nonlinear and mixed integer optimization problems which represent the primary focus in this book. Section 1.3 illustrates applications of nonlinear and mixed integer optimization that arise in chemical process design of separation systems, batch process operations, and facility location/allocation problems of operations research. Finally, section 1.4 provides an outline of the three main parts of this book. [Pg.3]

Premises Expression system defined Process scalability Primary definition of process No validation Refinement of operational control parameters Development of scale-down process models for validation Process out-of-limit definition Finalization of process control parameters Fixed and defined process and products Pivotal process validation and characterization studies Validated production process Well-characterized product Robust process ... [Pg.390]

Characterization starts once the synthetic route has been selected, although there will be opportunities to modify the route if the changes do not impact the final solid state or impurity profile of the final active pharmaceutical ingredient. The primary objective is to understand, through experimentation, the chemical and physical chemical processes involved in the transformation of raw materials to intermediates and products. The primary outcome is a process definition that includes the order of manufacturing steps, process parameter control methodology, process parameter limits, raw material specification, and diagnostic metrics. [Pg.53]

Detailed kinetic schemes also consist of several hundreds of species involved in thousands of reactions. Once efficient tools for handling the correspondingly large numerical systems are available, the extension of existing kinetic models to handle heavier and new species becomes quite a viable task. The definition of the core mechanism always remains the most difficult and fundamental step. Thus, the interactions of small unsaturated species with stable radicals are critical for the proper characterization of conversion and selectivity in pyrolysis processes. Parallel to this, the classification of the different primary reactions involved in the scheme, the definition of their intrinsic kinetic parameters, the automatic generation of the detailed primary reactions and the proper simplification rules are the important steps in the successive extension of the core mechanism. These assumptions are more relevant when the interest lies in the pyrolysis of hydrocarbon mixtures, such as naphtha, gasoil and heavy residue, where a huge number of isomers are involved as reactant, intermediate and final products. Proper rules for feedstock characterizations are then required for a detailed kinetic analysis. [Pg.150]

Zsigismody, as the first one, drew attention to adsorption on the capillary inner walls which is primary in relation to the capillary condensation [139]. This unusually correct observation corresponds to modern views about the processes of gases and vapours uptake by porous (i.e. industrial) adsorbents. Such a process usually includes mono- and multilayer adsorption followed by the capillary condensation in the final stage of uptake. A quantitative part of capillary condensation in the uptake of a definite vapour changes for different adsorbents depending on their porous structure. This process is dominant for the adsorbents where mesopores constitute a larger part [140]. [Pg.17]


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