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Interactions between Functional Elements

As a first step towards answering the above and related questions, we must define what we mean by interaction between functional elements. A functional element is defined by four sets the set of functional parameters, the set of dependencies, the set of influences, and the set of functions between the elements of the three first sets. Any or all of these sets could be involved in an interaction, but as the main purpose of a functional element is to represent what an object does, in particular as seen from the users point of view, and the purpose of decomposing a functional element into a set of interacting elements is to partition [Pg.225]

Two functional elements interact if the values of one or more functional parameters in one element depend on the values of one or more functional parameters in the other element. [Pg.226]

With this in mind, we see that there are four different combinations of the two types of variables, dependencies and functional parameters, for each of two elements A and B, as shown in Fig. C5.1. But in each case, the variable(s) of one element must be identical to the variable(s) in the other element. That is, the possibility of the interaction must already be inherent in the two elements a system is created when one or more of these possibilities are realised in a particular case by setting the values of the common variables equal to each other, and this equality relationship is symmetrical. [Pg.226]

An understanding of the distinction between what we normally think of as the relationship between inputs and outputs to processes in the physical domain and the relationship between functional parameters and dependencies in the functional domain further requires us to realise that in the functional domain this may also be determined by the context in which the functional element finds itself in particular, how it is included in a system of functional elements. As an example, consider a function (e.g. a chemical process) that converts a raw material into a product with the help of thermal energy (heat). As a stand-alone function, the functional parameter production rate may be determined by the demand for the product, and as such is an input, whereas the energy consumption, a dependency, is an output. But if this functional element is used in a system with the electricity producing element, with the interaction being that the waste heat from the [Pg.226]


A guide to tire stabilities of inter-metallic compounds can be obtained from the semi-empirical model of Miedema et al. (loc. cit.), in which the heat of interaction between two elements is determined by a contribution arising from the difference in work functions, A0, of tire elements, which leads to an exothermic contribution, and tire difference in the electron concentration at tire periphery of the atoms, A w, which leads to an endothermic contribution. The latter term is referred to in metal physics as the concentration of electrons at the periphery of the Wigner-Seitz cell which contains the nucleus and elecUonic structure of each metal atom within the atomic volume in the metallic state. This term is also closely related to tire bulk modulus of each element. The work function difference is very similar to the electronegativity difference. The equation which is used in tire Miedema treatment to... [Pg.220]

For non-interacting fluid elements, the RTD function is thus equivalent to the joint PDF of the concentrations. In composition space, the joint PDF would he on a one-dimensional sub-manifold (i.e., have a one-dimensional support) parameterized by the age a. The addition of micromixing (i.e., interactions between fluid elements) will cause the joint PDF to spread in composition space, thereby losing its one-dimensional support. [Pg.29]

We also calculated the partition function, based on Eq. (26), with n = t.13 In this case, Eq. (28) expresses an exact partition function for a short chain with no restrictions being imposed on the maximal range of interactions between chain elements. Our calculations showed that, for low values of x and t, the partition function is given almost exactly by the term which is proportional to the largest eigenvalue. It is found that 1 - Z (x)/Zj0>(x), with Z (0)(x) = (s, p )(l rj, is a very small... [Pg.279]

There are two basic elements as to why it is economically efficient to have both characteristics— current product production and new production— present in one firm. The first element relates to corporate finance and the sources and uses of cash flows in the firm. The second element relates to the efficiencies that can be gained by resorting to markets within the firm (as opposed to external markets that are thought of in conventional microeconomic theory).It should be obvious from the discussion that follows there is an inherent interaction between these elements. This discussion also points out the entrepreneurial function in the firm and its implications for considering the efficiency of the firm. [Pg.1451]

The number of chemical reactants determines the dimension of a chemical system. The minimum number is necessarily one, however the interaction between the elements is interesting thus systems with at least two reactants is relevant in the context of the present paper. In mathematical terms, a solution is a line represented by x = x t) as a function of time element. Representation of this solution has been in basically two different forms which will be discussed below ... [Pg.57]

Another, a similar route that considers interactions between individual elements of a system, is the reference interaction site model, RISM. The theory involves computations of the system structure by means of the probability density function, which describes location of all N particles of the system. The binary interactions define the pair-density function ... [Pg.166]

A fault tree for the infrared gas transmitter example, using C-gates, is given by Figure 4. To deal with interactions between functions and material elements, a 3-step approach is proposed (Brissaud, 2008). That is, the safety function to be evaluated measure gas... [Pg.1477]

Landscape ecology differs from classical ecology in that it focuses on spatial patterns and broadscale research on how spatial patterning affects ecosystems. Theories of landscape ecology concentrate on the interaction and impact of people on landscape structure, function, and change. Landscape structure is determined by the spatial relationships between the elements common to all landscapes patches, edges, boundaries, corridors, and matrices. Landscape function is defined by interactions between spatial elements and patterns, such as quantity of habitat, size of landscape structures, and landscape connectivity. Landscape change is determined by modifications in the structure and function of landscape over time. [Pg.1099]

Identify the subset of the system relevant to each safety function Focus attention on the functional interactions between the elements relevant to each safety function ... [Pg.212]

The first step of the proposed methodology is to handle the complexity of interactions between the elements of the organization in crisis time (Elaus 2010). Each element of the organization can be seen as a resource in the model and missions are expressed as functions. [Pg.954]

The inherent reason lying at the core of the problem of security in railways is the complexity of the railway system itself. Like in most of the large-scale systems, the complexity exists not only in the organizational structure and operational functions of railways but also in the relations and interactions between different elements of the system. It is for this reason that the problem of security in railways cannot be tackled without duly considering such complexity. [Pg.368]

Dehydrogenation, Ammoxidation, and Other Heterogeneous Catalysts. Cerium has minor uses in other commercial catalysts (41) where the element s role is probably related to Ce(III)/Ce(IV) chemistry. Styrene is made from ethylbenzene by an alkah-promoted iron oxide-based catalyst. The addition of a few percent of cerium oxide improves this catalyst s activity for styrene formation presumably because of a beneficial interaction between the Fe(II)/Fe(III) and Ce(III)/Ce(IV) redox couples. The ammoxidation of propjiene to produce acrylonitrile is carried out over catalyticaHy active complex molybdates. Cerium, a component of several patented compositions (42), functions as an oxygen and electron transfer through its redox couple. [Pg.371]

The safe operation of a chemical process requires continuous monitoring of the operation to stabilize the system, prevent deviations, and optimize system performance. This can be accomplished through the use of instrumentation/control systems, and through human intervention. The human element is discussed in Chapter 6. Proper operation requires a close interaction between the operators and the instrumentation/control system. To a large extent, batch operations have simple control systems and are frequently operated in the manual mode. The instrumentation system is the main source of information about the state of the process. Some of the typical functions of the instrumentation/control system are... [Pg.109]

Mn02) [56], The XANES spectra at the Ni K-edge indicates that, unlike the ABS alloys, there is very little interaction between hydrogen and Ni but rather strong interactions with Ti, V, and Zr. The hydrogen is presumably located in tetrahedra that contain large fractions of these three elements, whereas the Ni-rich sites are probably empty. Thus the function of Ni in AB2 alloys may be primarily to serve as a catalyst for the electrochemical hydriding reactions. [Pg.227]

Instead of activating transcription the cortisol-induced GR represses IL-6 synthesis and, even more surprisingly, repression does not involve the GRE elements, but rather the kB site (Fig. 1). It appeals that of a monomeric GR protein without itself touching the DNA interacts with the RelA component of NF-kB [3]. As a result GR blocks the action of NF-kB. The negative interference by this crosstalk is not restricted to NF-kB, it occurs also with AP-1 and CREB, and with several other transcription factors not relevant for IL-6 expression. A nuclear isoform of the LIM protein Trip6 mediates the interaction between these factors and is required for the inhibitory GR function. This interesting negative crosstalk is part of the immune-suppressive action of cortisol. [Pg.1228]

The matrix elements of the inactive electrons and the interaction between the active and inactive electrons can be approximated by expressing the corresponding potential surfaces as a quadratic expansion around the equilibrium values of the various internal coordinates, and by nonbonded potential functions for the interaction between atoms not bonded to each other or to a common atom ... [Pg.61]


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