Principle of the Process

After collecting from the literature a large quantity of data concerned with the diffusivity of various diffusing substances in different polymers, it has been possible for the authors [9-11] to refine an equation relying on the experimental values of the diffusivity of polyolefin material. The refined equation thus obtained is worth citing  

Moreover, various values of these parameters are listed for the following polymers low-density polyethylene (LDPE), high-density polyethylene, and polypropylene (PP) [9]. 

Finally, the principle of an infinite coefficient of convection in a finite volume of liquid was presented. 

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Principles of the Processing of Plastics 8.2.6 Thermal Properties Affecting Cooling... 

Later developments which have had more impact on copper smelting relate to an approach which combines roasting, smelting and converting steps in one reactor, thereby making the copper production process continuous. The three unique continuous processes tried in operation are (i) the Worcra process, (ii) the Noranda process and (iii) the Mitsubishi process. The principles of the processes are respectively shown in Figures 4.5 to 4.7. 

Figure 6.21 illustrates the principle of the process in terms of the molecular orbitals involved. Excitation of the fluorophore causes an... 

A more recently introduced concept, described by Staniforth et al. [17] involves the use of electrophotographic principles (essentially those used in the photocopying process) as a basis for the application of dry powder coatings to pharmaceutical tablets. This concept is illustrated in Figure 19. Although representing an early prototype, the essential principles of the process are clearly outlined. The salient features of this process are ... 

Figure 11 Memstill technology of seawater desalination developed at the TNO institute (a) principle of the process (b) cost comparison with other desalination techniques. (From Ref. 226.)...

But what must one know before "constructing any (including kinetic) model First its basic elements, secondly the main laws and principles of the processes that are to be accounted for by the model, and thirdly the algorithm (the instruction) for the model construction. For kinetic models the basic elements are chemical substances and elementary acts the main laws are the laws of mass action and surface action the algorithms for model construction are the methods to derive kinetic equations suggested by Tern-kin, those to determine kinetic equation constants, etc. 

This chapter describes basic physico-chemical relations between the gas phase transport of atoms and molecules and their thermochemical properties, which are related to the adsorption-desorption equilibrium. These methods can either be used to predict the behavior of the adsorbates in the chromatographic processes, in order to design experiments, or to characterize the absorbate from its experimentally observed behavior in a process. While Part I of this chapter is devoted to basic principles of the process, the derivation of thermochemical data is discussed in Part n. Symbols used in the following sections of Part I are described in Section 5. For results, which were obtained applying the described evaluation methods in gas-adsorption chromatography, see Chapters 4 and 7 of this book. 

Granulation. Almost all new plants that make granules use the Hydro-Agri process, which can be built to make over 3000 tonnes per day. The basic principle of the process involves the spraying of the melt onto recycled seed particles or prills circulating in the granulator. The process is described in more detail in References 108, 109 to 110. 

The basic principle of the process, which is licensed by IFP SNAM (Societa Nazionale Metanodotii) etc., comprises preheating of the hydrocarbon feedstock and boiler feed-... 

In solution impregnation, a porous support is infiltrated with a solution of the active phase or its precursor. After careful removal of the solvent, a high dispersion of the active phase over the whole support is obtained (if a precursor of the active phase is used, a conversion step after drying is necessary). The basic principle of the process is shown in Figure 10.21. 

Fig. 38. Photon emission at a semiconductor, (a) Principle of the process at a p-type semiconductor, (b) Photon map taken on a GaAlAs/GaAs multiquantum well. Electrons are injected into GaAlAs and recombine in p-GaAs, from which light is emitted (after [140]).

If the components of a binary mixture are immiscible, the vapor pressure of the mixture is the sum of the vapor pressures of the two components, each exerted independently and not as a function of their relative concentrations in the liquid. This property is employed in steam distillation, a process particularly applicable to the separation of high boiling substances from non-volatile impurities. The steam forms a cheap and inert carrier. The principles of the process also apply to other immiscible systems. 

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