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Constraints spatial

Method Quantity Measured Key Assumptions and Constraints Spatial Footprint (X) and Time Resolution (T)... [Pg.43]

The analysis of interdependencies needs a system description, which means that the main event should be thoroughly described as a scenario, specifying physical location, environmental conditions and constraints, spatial and temporal scales, technical and organizational systems, operating factors, and physical objects affected immediately. The six dimensions of Rinaldi et al. (2001) can be used as input to the description (Table 1). [Pg.1769]

The second-order nonlinear susceptibility tensor ( 3> 2, fOj) introduced earlier will, in general, consist of 27 distinct elements, each displaying its own dependence on the frequencies oip cci2 and = oi 012). There are, however, constraints associated with spatial and time-reversal symmetry that may reduce the complexity of for a given material [32, 33 and Ml- Flere we examine the role of spatial synnnetry. [Pg.1273]

After adsorption, species may diffuse on the surface or, eventually, become absorbed in the bulk. Due to collisions between adsorbed species of different kinds the actual reaction step can occur. Of course, this step requires that some energetic and spatial constraints have to be fulfilled. The result of the reaction step is the formation of a product molecule. This product can be either an intermediate of the reaction or its final output. [Pg.389]

Notice that in this example, the speed of the packet is inversely proportional to the packet s spatial size. While there is certainly nothing unique about this particular representation, it is interesting to speculate, along with Minsky, whether it may be true that, just as the simultaneous information about position and momentum is fundamentally constrained by Heisenberg s uncertainty relation in the physical universe, so too, in a discrete CA universe, there might be a fundamental constraint between the volume of a given packet and the amount of information that can be encoded within it. [Pg.663]

Psueudopotentials should satisfy several basic requirements. For example, the pseudo and real

wave functions must be identical outside the core radius (>rc), not only in their spatial dependence but also in their absolute magnitudes such that two wave functions generate identical charge densities. The equality of the two types of wave functions outside the core radius in this context is guaranteed by imposing the following constraint ... [Pg.20]

A great deal of research remains to be done in this area. We are currently extending in the study of spatial correlations in the non-equilibrium fluids to time correlations with the hope of establishing a correspondence between MD and fluctuating hydrodynamic theory. We are also using these systems to study the roles of viscosity and conductivity in fluid behavior under different external constraints. Finally, we plan to continue our research into the formation of spatial structures in fluids. [Pg.251]

Ad(ii) On catalysts with pores and cavities of molecular dimensions, exemplified by mordenite and ZSM-5, shape selectivity provides constraints of the transition state on the S 2 path in either preventing axial attack as that of methyl oxonium by isobutanol in mordenite that has to "turn the comer" when switching the direction of fli t through the main channel to the perpendicular attack of methyl oxonium in the side-pocket, or singling out a selective approach from several possible ones as in the chiral inversion in ethanol/2-pentanol coupling in HZSM-5 (14). Both of these types of spatial constraints result in superior selectivities to similar reactions in solutions. [Pg.609]

Instead of using repeated solution of a suitable eigenvalue equation to optimize the orbitals, as in conventional forms of SCF theory, we have found it more convenient to optimize by a gradient method based on direct evaluation of the ener functional (4), ortho normalization being restored after every parameter variation. Although many iterations are required, the energy evaluation is extremely rapid, the process is very stable, and any constraints on the parameters (e.g. due to spatial symmetry or choice of some type of localization) are very easily imposed. It is also a simple matter to optimize with respect to non-linear parameters such as orbital exponents. [Pg.167]

In the HF scheme, the first origin of the correlation between electrons of antiparallel spins comes from the restriction that they are forced to occupy the same orbital (RHF scheme) and thus some of the same location in space. A simple way of taking into account the basic effects of the electronic correlation is to release the constraint of double occupation (UHF scheme = Unrestricted HF) and so use Different Orbitals for Different Spins (DODS scheme which is the European way of calling UHF). In this methodology, electrons with antiparallel spins are not found to doubly occupy the same orbital so that, in principle, they are not forced to coexist in the same spatial region as is the case in usual RHF wave functions. [Pg.192]

Depending upon lithologic and structural relationship with host rocks, mineralogy, attendant alteration, paragenesis and spatial and temporal constraints, the uranium resources of the world can be assigned to the 15 main categories of uranium ore deposits. They have been shown numerically numbered in sequence in the order of their approximate economic significance in Table 1.18. At present, only 7 can be said to be economically important (see Table 1.19) and these account for more than 95% of the world resources of ura-... [Pg.73]

The values of branching probability with cobalt are in general more than two times higher in the beginning of an experiment than at steady state. It is concluded that initially the spatial constraints on the growth sites are lower than at steady state. This also indicates a change in the nature of the growth sites. [Pg.174]

Branching reactions appear to be a unique indication of the existence of spatial constraints at growth sites. Analogies between homogeneous and heterogeneous catalysis are pertinent. [Pg.175]

Increased spatial constraint effects on growth sites are evident from Figure 9.20. This figure shows the contents of individual monomethyl-branched compounds in carbon number product fractions. Note that their values decline by a factor of 5 to... [Pg.177]

FIGURE 9.20 Methyl-branched isomers in carbon number fractions at 1.2 bar (left) and 9 bar (right) during FT synthesis on cobalt as indications for spatial constraints on the growth sites. Further legend as in Figure 9.18. [Pg.178]


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