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Complex scaling practical implementations

In practical implementations of complex scaling, the Hamiltonian is regularly discretized in finite space, for example, in a box of radius R. This yields a discrete pseudo-continuum with energies that fulfill Ek e w for Z = 0 and approaches it with increasing k and R for Z 0. If exterior complex scaling is made in such a finite box, Eq. (15) is adjusted to... [Pg.257]

The field of biocatalysis differs substantially from that of traditional chemical asymmetric catalysis. Whereas the range of optimal operational conditions may be broader for the latter case, the issue of substrate specificity of the former is more complex. The practical integration of biological catalysts into synthetic schemes has two main requirements (1) a suitable biocatalyst able to perform the required transformation must be identified and (2) the ability of the identified biocatalyst to perform the required transformation efficiently on the target substrate on a preparative scale must be assessed and if necessary engineered. Both of these requirements have been recognized and efforts to facilitate the implementation of biocataysts have been studied.2... [Pg.335]

On a larger scale, more-complex models can be used to represent the types of whole systems or components and are usually shown pictorially. In an abstract model, the attributes and their types are chosen to help specify the operations on the component as a whole and, according to good object-oriented analysis practice, are based on a model of the domain. However, anyone who has been involved in practical OOD is aware that the design phase introduces all sorts of extra classes as patterns are applied to help generalize the design, make it more efficient, distribute the design, provide persistence or a GUI, and so on. But we can still retrieve the abstract model from any tme implementation in the same way as for the simpler models. [Pg.246]

In our most straightforward implementation of VTST for gas-phase reactions, rather than allow arbitrary orientations of the dividing surface, we consider a one-parameter sequence of dividing surfaces that are defined in terms of a reaction path [12,13]. This procedure is applicable to complex problems, and it immediately provides a practical improvement over the conventional choice of placing the dividing surface at the saddle point. A robust choice for the reaction path is the minimum energy path (MEP), that is, the path of steepest descent in the mass-scaled coordinates [14]. The coordinates on this path are denoted q (j ) as a function of a progress variable s, and the path is defined by... [Pg.71]

The field is wide and the topics quite different in terms of relative experimental complexity and economy with respect to potential industrial applications. Synthetic processes for some of the monomers and polymers described in the various chapters appear to comply with the requirements associated with a viable scale-up. This is particularly the case if the precursors are already industrial commodities or readily available, as in the cases of the direct polymerisation of pristine oils, use of different derivatives of castor oil, or exploitation of epoxidised oils. Other systems, despite their high potential, appear to require further work at a more practical level to assess their feasibility and possible implementation. This will require the combined efforts of polymer chemists and process engineers, among other experts. [Pg.145]

Despite the enormous success of the zeolite membrane, practical application in a larger scale is still limited. Several factors such as cost of membrane development, reproducibility, long-term stability, and the method for the preparation of the defect-free membrane restrict its implementation in the industry. Molecular simulations become a powerful tool to predict the catalytic behavior of zeolite [14]. Compared to the experimental process, it is rapid and convenient, is cost effective, can handle more complex systems within a reasonable period of time, and results to better understanding of the system. Many computer simulation methodologies have been employed to understand the physicochemical properties of zeolite such as adsorption characteristics [15], diffusion and permeation [16], catalytic reaction [17], and also the nature of the acidic site [18,19]. The main concern of this work is to design a membrane using computer simulation methodology. [Pg.24]


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