Specify Components

Type the name of the component in the left-hand column of the window. If you type in a name and the third column is not automatically hlled in (as in Fig. C.5a for C5H12), double-click on the blank box in the third column. Type the name into the window that appears (Fig. C.5b), choose Find Now, and search for your chemical in the list provided. Close the window after specifying all the chemicals appearing in your process. 

---

Appendix III contains failure rate estimates for various genetic types of mechanical and electrical equipment. Included ate listings of failure rates with range estimates for specified component failure modes, demand probabilities, and times to maintain repair. It also contains some discussion on such special topics as human errors, aircraft crash probabilities, loss of electric power, and pipe breaks. Appendix III contains a great deal of general information of use to analysts on the methodology of data assessment for PRA. 

To determine the number of purge cycles and achieve a specified component concentration after j purge cycles of pressure (or vacuum) and relief [29] ... 

For fixed tower temperature, pressure, gas feed rate, specified or assumed operating (Lq/Vx+i) times minimum value, specified component recovery out of inlet gas. 

Having ascertained the nature of the constituents of a given sample, the analyst is then frequently called upon to determine how much of each component, or of specified components, is present. Such determinations lie within the realm of quantitative analysis, and to supply the required information a variety of techniques is available. 

The fact that the same equilibrium mixture is attained whether we start wTith the-substances on the left, or those on the right, follows from the condition that this shall be a state of true equilibrium. Fox if two equilibrium mixtures, say a and a, could result in the two cases, one would of necessity contain the components in proportions different from those in the other. The one, say a, which contains any specified component in excess over the other mixture, could be produced from the latter by adding to it the requisite excess of that component. But if a is a state of true equilibrium this will necessarily give rise to some chemical change in the system, and hence a cannot be a state of true equilibrium if it differs at all from a. 

Now suppose that, at a particular composition of the liquid, the total pressure increases as the liquid becomes richer in a specified component, say I. Expansion (i.e., distillation) can then, by the above rule, only diminish the concentration of I. in the liquid. The concentration of I. in the vapour is therefore, at that point, not less than its concentration in the liquid, for if it could be less, any possible evaporation would necessarily increase the concentration of I. in the liquid. 

If, however, the total pressure is decreased by increasing concentration of a specified component in the liquid, compression (i.e., liquefaction) cannot increase the concentration of that component in the liquid, and hence its concentration in the vapour is not greater than that in the liquid. 

It therefore follows that a transition from a rising to a falling part of a vapour pressure curve can occur only when the concentration of a specified component in the vapour is neither greater... 

Then if any two phases are separately in equilibrium with a third phase, they are also in equilibrium when placed in contact, so that if any one phase (e.y., the vapour) is taken as a test-phase, and the other phases are separately in equilibrium with this, the whole system will be in equilibrium. Under the conditions imposed, it is sufficient that the vapour pressure, or osmotic pressure, of each component has the same value at all the interfaces, for we may consider each component separately by intruding across the interface a diaphragm permeable to that compo- -nent alone. Then if the vapour, or osmotic pressures, are not equal at the third interface to their values at the first and second interfaces, i.e., at the interfaces on the test-phase, we could carry out a reversible isothermal cycle in which any quantity of a specified component is taken from the test-phase to the phase of higher pressure, then across the interface to the phase of lower pressure, and then back to the test-phase. In this cycle, work would be obtained, which however is impossible. Hence the two phases which are separately in equilibrium with the test-phase are also in equilibrium with each other. This may be called the Law of the Mutual Compatibility of Phases (cf. 106). 

In the simplest cases, the solvent may consist of one specified component, although in fact in a steady-state cyclic process it is highly unlikely that the solvent will ever come back to the initial composition at time zero. Rather, perhaps, one can say that make-up will entail addition of one material only. Again, clearly this need not be a pure compound, but its composition should be consistent. The single solvent offers limited scope for manipulating the system since it alone must meet all process and operational requirements. In other words, it must satisfy all aspects that will lead to an overall viable system. These aspects include selectivity, capacity, solubility, mass transfer, phase separation, costs, among others. The solvent is, therefore, a mixture components. The solvent components are extractant, (ii) diluent, (iii) modifier, and (iv) synergist. 

Estimate the flow-rates L, V and L, V from the specified component separations and reflux ratio. 

Segmental) adsorption energy (exchange of a specified component pair). 

A complication to the calculation procedure for holding an aqueous species at fixed activity is the necessity of maintaining ionic charge balance over the reaction path. If the species is charged, the model must enforce charge balance at each step in the calculation by adjusting the concentration of a specified component, as discussed in Section 4.3. For example, if the pH is fixed over a path and the charge balance component is Cl-, then the model will behave as if HC1 were added to or removed from the system in the quantities needed to maintain a constant H+ activity. 

The rest of this chapter deals with how to model and specify components executable units that can be plugged together with different interaction schemes connecting them. Our modeling approach is based on the ideas put forth in three definitions. 

We have applied the Catalysis ideas of modeling and behavioral abstraction to enable us to specify components aside from their implementations. We have also shown how to check that plugging a set of heterogenous components together meets a given set of requirements. 

This Chapter has two main parts. Section 14.1, Patterns for Specifying Components, on page 613, describes patterns often useful when building a component specification. Section 14.2 onwards illustrates the construction of a specification for the case study. 

Pattern 14.30, Specify components (p.615) motivates the extra effort involved in separating specification of expected behavior from its implementation. Pattern 14.31, Bridge requirements and specifications (p.617) outlines a pragmatic view of requirements, as stated and understood by a user, and the more precise specifications that a developer might use to understand what must be built. Pattern 14.32, Use-case led system specification (p.619) explains why a use-case driven approach to requirements capture is prudent, but should always be interleaved with tools of more precise specifications. 

Pattern 14.36, Construct a system behavior spec (p.628) — Pattern 14.38, Using state charts in system type models (p.636) describe concrete techniques to build the specification of the system of interest. Pattern 14.39, Specify component views (p.640) and Pattern 14.40, Compose Component views (p.642) explain how to show that separately specified components, when composed together in a particular way, realize the required behavior. 

Often, the context model will yield several classes of user, each with a different view of the system see Pattern 14.39, Specify component views (p.640) and Pattern 14.40, Compose Component views (p.642). 

Every specification is part of a larger implementation and every implementation composes a solution from specified components. 

We have several separately constructed views — Pattern 14.39, Specify component views (p.640). 

The requirements for animal facilities, housing, and environmental conditions are as described for subchronic studies. Special attention must be paid to diet formulation because it is impractical to formulate all of the diets for 2-year study from a single batch. In general, semisynthetic diets of specified components should be formulated regularly and analyzed before use for test material content. 

N matrix of numbers of specified components in the SJj) molar entropy of species./ (J K-1 mol-1)... 

---