Primary constraint

The availability of resources to perform the analysis is the primary constraint on the completeness of QRAs. Managers must balance the value of QRA results in their decision making against the cost of obtaining these results. It has been shown repeatedly that, when properly... 

The following sections of this chapter demonstrate the applicability of the above-mentioned adaptations to completely batch operations using an hypothetical example of completely batch processes drawn from experience at an agrochemical facility. Initially, time is treated as the primary constraints and concentration as... 

It is worthy of note that the problem solution is such that in each time subinterval, the concentration constraints is met. This implies that, as long as water is available at the right time, it can safely be reused in any of the time subintervals within the concentration interval, i.e. the secondary constraints (concentration) is met in every step of the analysis, and the primary constraints (time) guides the formulation of the final solution (target design network). 

The foregoing analysis was mainly based on time taken as the primary constraints and concentration taken as the secondary constraints. It has been shown that this primary constraints can be bypassed by merely using storage facilities, as long as the secondary constraints is met. However, it is also possible to take concentration as the primary constraints and time as the secondary constraints. The procedure and the associated outcome of such an analysis form the subject of the following section. 

Figure 12.19 shows the implication of concentration taken as a primary constraints and time taken as a secondary constraints. The concentration scale represents the maximum inlet and outlet concentrations in the given processes. This concentration is increasing in the direction of the arrow on the scale. Processes A and D precede processes B and C, respectively. This implies that the secondary constraints (time) is satisfied in both case (i) and case (ii). Moreover, water from process A has concentration less than the maximum concentration allowed in process B. Therefore, in case (i) both the concentration and time constraints are met and water from process A can safely be reused in process B. However, water from process D has concentration higher than the maximum concentration allowed in process C, which implies that the primary constraints (concentration) is not met. Therefore, water from process D cannot be reused in process C, although the secondary constraints (time) is met. 

The same hypothetical example was used to illustrate the targeting procedure for a case where concentration is treated as a primary constraints. The problem specification still remains the same as that used Section 12.2.2 (Table 12.2). 

Fig. 12.19 Implication of concentration taken as a primary constraints (Majozi et al., 2006)...

Instead of splitting the problem into concentration intervals and time subintervals, the problem is split into time intervals and concentration subintervals, with water demand plotted on the horizontal axis. The boundaries for time intervals and concentration subintervals are set by the process end-points. However, unlike in a case where time is taken as a primary constraints, the streams that are required or available for reuse in each concentration subinterval are plotted separately. This approach has proven to ease the analysis as will be shown later in this section. 

The fresh water target for the first sequence of this system of batch processes is, therefore, 1560 kg. This target is exactly the same as that obtained in Section 12.2.2 when time was taken as the primary constraints. 

The primary constraint on the coordination number is the anion-anion repulsion. Clearly this determines the maximum possible coordination number and, for hard cations, this is normally the coordination number that is observed. However, if the cation is soft or if the maximum possible coordination number gives rise to very small bonding strengths, other coordination numbers may be found as discussed in Section 6.3. A number of examples will illustrate how these various factors work together. 

Is a primary constraint the central problem in any analysis of ionization mechanisms is the kinetic study of the Interconversion processes between the different species for such a kinetic investigation to be complete all the elementary processes should be analyzed for their energetic and dynamic properties. Since the elementary steps in ionic association-dissociation processes are usually very fast - to the limit of diffusion- controlled reactlons-their kinetic investigation became only feasible with the advent of fast reaction techniques, mainly chemical relaxation spectrometric techniques. 

The primary constraint when choosing a suitable site location within... 

The polymict impactites are extremely important as primary constraints on the impact bombardment of the Moon. This bombardment... 

Identification knowledge. Once again, time plays a key role in the recognition of a situation. In the Vary situation, the primary constraint is that a relationship is expressed that will remain pertinent over time. The relationship binds two very different things either two distinct categories (e.g., for every dog there are three bones.. . . ) or one thing and a numerable property (e.g., each apple costs 35 cents.. . . ). The important aspect is that the relationship holds for more than a single instance and is almost infinitely extensible. That is, it is true for every dog, for example, not just a specific one, and it holds not just for one apple but for as many apples as one cares to purchase. Thus, the relationship expressed has a different nature than that of the Restate situation, which demands specificity. Often, the Vary situation has a conditional form, either explicitly stated as If X, then Y or implicitly expressed. 

Hence, we can introduce a I = exp(T)IO) and a suitable form for and we have a set of equations for a CC approach to excited states. The primary constraint on is that it be able to provide the exact result in the limit. Hence, if we choose a Cl-like operator. 

W is the minimum number of workers required to cover a seven-day-a-week operation with the following primary constraints satisfied ... 

Type Neutron reaction Fuel (% enrichment) Cladding Moderator Coolant pressure (bar) Primary inlet-outlet Temp. (X) Primary constraint Remarks... 

The model provides a batch computation of standard hoist calculations with three primary constraints friction over the drum, safety factor of the ropes, and power output of the hoist motor. This model was then further developed to include hoists with two skips and hoists with one skip and a balance mass. Balance ropes are included in all calculations such that the balance ropes and head ropes have equal mass. The model conducts an initial calculation based on the strength of the hoist motor, depth of the shaft as well as the combined mass of the ore and skip. Adjustments are then made to the skip mass to ensure acceptable friction between... 

The source for a standard external modulation link operates CW thus, there are no modulation requirements on the laser. This removes the primary constraint, which in the direct modulation case limited the laser choice to semiconductor lasers. Conceptually, then, any type of laser could serve as the source for an external modulation link. Early external modulation hnks used semiconductor diode lasers, but more recently the majority of external modulation Hnks have been fed by soHd-state lasers. 

Despite advancement in the development of direct methanol fuel cells (DMFCs), some restrictions still inhibit their large-scale commercialization. This chapter has discussed one of the primary constraints, that is, identification of appropriate membrane materials. Nafion membranes that dominate the market of polymer electrolyte membranes allow methanol permeation from the anode to the cathode side of a DMFC. This results in serious negative consequences. Three approaches have been pursued in order to resolve the methanol permeation problem. These include Nafion membranes modification, development of alternative membranes and provision of high activity anode catalysts or methanol tolerant cathode catalysts. All the three options have achieved certain degree of success in solving the problan. Of particular interest are the Nafion membranes modification and development of alternative membranes in which membranes with permeability values of 10 to 70 times lower than the pure Nafion membranes have been developed. In general, based on the tremendous research efforts being made to develop DMFCs membranes with the best qualities, we are optimistic that very soon the issue of methanol permeation shall become a history. 

From the information provided in the charts, the subset of materials which maximize the performance of components after having fixed the primary constraints are found. Resistance to corrosion, modulus, strength and density are all primary constraints which must be met. The constraints may eliminate several classes of materials. The constraints are given by... 

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