Macroscopic Characterization

Analytical characterization includes measurement of absolute sizes and concentrations of species present in the catalyst. For the purpose of clarity, these techniques have been organized, starting with the bulk macroscopic properties, down to the component, microscopic features. The underlying goal of analytical characterization is to provide information about the sample which will allow research personnel to relate the properties measured to some aspect of a catalyst s performance, either in the field or in the evaluation laboratory. Macroscopic characterization includes both chemical compositions and physical properties such as particle size, density and total surface area. Chemical analysis techniques are well... 

The heteroatom profiles shown for these SRC s in Figures 3, 4, and 5 provide a useful macroscopic characterization of the coal liquid components within a given chromatographic fraction. This information when coupled with comparable data on hydroprocessed coal liquids can yield valuable insights into the nature of the heteroatom removal reactions (3). 

Strictly speaking, the oscillation terms arising near the interface of different materials should be considered in the above discussion [16]. However, the purpose of the present work is to macroscopically characterize the fracture behavior of the adhesive interface for the design of civil structures. Hence, the inhomogenity of the specimen was neglected for the evaluation of the macroscopic fracture toughness. 

This model of the liquid will be characterized by some macroscopic quantities, to be selected among those considered by classical equilibrium thermodynamics to define a system, such as the temperature T and the density p. This macroscopic characterization should be accompanied by a microscopic description of the collisions. As we are interested in chemical reactions, one is sorely tempted to discard the enormous number of non-reactive collisions. This temptation is strenghtened by the fact that reactive collisions often regard molecules constituting a minor component of the solution, at low-molar ratio, i.e. the solute. The perspective of such a drastic reduction of the complexity of the model is tempered by another naive consideration, namely that reactive collisions may interest several molecular partners, so that for a nominal two body reaction A + B —> products, it may be possible that other molecules, in particular solvent molecules, could play an active role in the reaction. 

The temperature and the chemical potential are direct macroscopic observables par excellence. Since the quantum mechanics say rules that the observable size may be represented by the self-adjoint operators formed on the Hilbert space, is adding the interest to associate the operators for the temperature and the chemical potential for an adequate macroscopic characterization. 

In nanotechnology numerical simulation can help to predict properties of new materials that do not yet exist in reality. And it can help to identify the most promising or suitable materials. The trend is towards virtual laboratories in which materials are designed and studied on a computer. Simulation offers the possibility of determining mean or average properties for the material macroscopic characterization. At... 

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