Boundary-defined definition

Artificial boundaries have been defined as boundaries at which the occupation probability of one or more sites obeys special equations, not covered by the analytic expression r(n) and g(n) that apply to the other n. The variety of possible artificial boundaries is, of course, endless. A restricted class are the pure boundaries, defined as those in which only the end site requires a special equation. Another subdivision is in reflecting boundaries those which conserve total probability and absorbing boundaries, at which probability disappears. The latter definition requires comment. 

The regional boundary defines the geographical limits within which impacts will be considered (local, national, regional, continental, and global). The definition of these boimdaries may depend on the nature of the registered emissions. 

Establishing the physical and analytical boundaries for a QRA is also a difficult task. Even though you will provide input, the scope definition will largely be made by the QRA project team. Defining the physical boundaries is relatively straightforward, but it does force the QRA team to explicitly identify and account for interfaces that may significantly affect the QRA results. Eor example, analysts often treat a connection to a power supply (e.g., a plug) or a feed source as a physical boundary yet, loss of power or contamination of the feed must be considered in the QRA model. 

Due to such subtleties, the need to develop well-defined basic events, failure modes, and equipment boundaries prior to data encoding cannot be overemphasized. Familiarity with failure definitions and failure severities will be extremely helpful to the analyst. Figures 2.1 and 2.2, reprinted from IEEE Std. 500-19845, list a large number of failure modes by failure severity and may help encode failures. IPRDS also contains helpful information on failure encoding. Information on some equipment boundaries may be found in the Data Tables in Section 5.5. 

Various materials (e.g., metal, plastics, or rubber) are used to make the flexing elements in these couplings. The use of the couplings is governed by the operational fatigue limits of these materials. Practically all metals have fatigue limits that are predictable, therefore, they permit definite boundaries of operation to be established. Elastomers such as plastic or rubber, however, usually do not have a well-defined fatigue limit. Their service life is determined primarily by conditions of installation and operation. 

A system is the region in space that is the subject of the thermodynamic study. It can be as large or small, or as simple or complex, as we want it to be, but it must be carefully and consistently defined. Sometimes the system has definite and precise physical boundaries, such as a gas enclosed in a cylinder so that it can be compressed or expanded by a piston. However, it may be also something as diffuse as the gaseous atmosphere surrounding the earth. 

The thickness of the boundary layer may be arbitrarily defined as the distance from the surface at which the velocity reaches some proportion (such as 0.9, 0.99, 0.999) of the undisturbed stream velocity. Alternatively, it may be possible to approximate to the velocity profile by means of an equation which is then used to give the distance from the surface at which the velocity gradient is zero and the velocity is equal to the stream velocity. Difficulties arise in comparing the thicknesses obtained using these various definitions, because velocity is changing so slowly with distance that a small difference in the criterion used for the selection of velocity will account for a very large difference in the corresponding thickness of the boundary layer. 

A triple point is a point where three phase boundaries meet on a phase diagram. For water, the triple point for the solid, liquid, and vapor phases lies at 4.6 Torr and 0.01°C (see Fig. 8.6). At this triple point, all three phases (ice, liquid, and vapor) coexist in mutual dynamic equilibrium solid is in equilibrium with liquid, liquid with vapor, and vapor with solid. The location of a triple point of a substance is a fixed property of that substance and cannot be changed by changing the conditions. The triple point of water is used to define the size of the kelvin by definition, there are exactly 273.16 kelvins between absolute zero and the triple point of water. Because the normal freezing point of water is found to lie 0.01 K below the triple point, 0°C corresponds to 273.15 K. 

Table 26.7 gives a list of the boundary conditions which define a tire wear test simulation and in fact also an acmal road test. The road surface is the laboratory surface on which the abrasion data for the simulation were obtained. There is as yet no definition of a road surface and even if there were one, it would be of httle use since road surface structures change frequently along the road surface as pointed out earlier. 

For phenomena involving electrons crossing the phase boundary (photocurrents, electron photoemission), the quantum yield j of the reaction is a criterion frequently employed. It is defined as the ratio between the number of electrons, N, that have crossed and the number of photons, that had reached the reaction zone (or, in another definition, the number of photons actually absorbed by the substrate) J=N /N. ... 

The limitation of using such a model is the assumption that the diffusional boundary layer, as defined by the effective diffusivity, is the same for both the solute and the micelle [45], This is a good approximation when the diffusivities of all species are similar. However, if the micelle is much larger than the free solute, then the difference between the diffusional boundary layer of the two species, as defined by Eq. (24), is significant since 8 is directly proportional to the diffusion coefficient. If known, the thickness of the diffusional boundary layer for each species can be included directly in the definition of the effective diffusivity. This approach is similar to the reaction plane model which has been used to describe acid-base reactions. 

In the first stage of the LCA analysis, it is necessary to define the objective and the scope of the paper before the actual start [35]. The study goal and scope definition determine the next procedure character and the circumstances in which the study outputs are valid [32]. [36] requires to establish a study goal and scope while the study scope means to determine the product system, the functional unit and system boundaries, to determine allocation rules, the assessment methodology, hypothesis and limits and data quality. 

Goal and scope definition, where the goal of the study is defined, the eventual alternatives that will be considered are given, the system boundary is determined and the processes within the product- or service-system are defined. 

When life is to be defined, it is necessary for the purposes of biogenesis research to limit the discussion to the simplest life forms. This type of reduction is necessary in order to be able to make a clear division between inanimate and animate objects. Even for reduced systems , the boundaries between the two become unclear, as shown by the example of viruses. A definition of minimal life makes it possible to ignore the complex properties of higher living organisms, such as consciousness, intelligence or ethics. 

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