Proposed Questions

What is the set point of a controller and what should be considered in defining it  

A The set point is the value you want as a process variable. It must be selected properly to ensure an efficient operating point. 

What is the most important information in a P ID and what type of user does it address  

Suppose that the tank in Fig. 3.17 has a level controller. Then, suddenly the input flow increases twice, and after a while, the tank reaches a new steady-state condition. What will the level be at the new steady state  

A Because the controller regulates the level and the set point has not been changed, the level will return to the set point, stabilizing the process at the same level prior to the disturbance. In addition, to satisfy the material balance, the input flow must equalize the output flow therefore, the relief valve will open more as the output flow should be double that of the input flow to maintain the system under steady state. 

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Other proposals question the efficiency of the present system of intellectual property rights as an incentive to innovation and point to a more radical change in the way R D on pharmaceuticals is organized these proposals... 

Provide a proposed reply stating what it is believed that the Code requires, and that clearly and concisely answers the proposed question. If, in the inquirer s opinion, a revision to the Code is needed, recommended wording shall be provided in addition to information justifying the change. 

In the same section, we also see that the source of the appropriate analytic behavior of the wave function is outside its defining equation (the Schibdinger equation), and is in general the consequence of either some very basic consideration or of the way that experiments are conducted. The analytic behavior in question can be in the frequency or in the time domain and leads in either case to a Kramers-Kronig type of reciprocal relations. We propose that behind these relations there may be an equation of restriction, but while in the former case (where the variable is the frequency) the equation of resh iction expresses causality (no effect before cause), for the latter case (when the variable is the time), the restriction is in several instances the basic requirement of lower boundedness of energies in (no-relativistic) spectra [39,40]. In a previous work, it has been shown that analyticity plays further roles in these reciprocal relations, in that it ensures that time causality is not violated in the conjugate relations and that (ordinary) gauge invariance is observed [40]. 

In our hydrogen molecule calculation in Section 2.4.1 the molecular orbitals were provided as input, but in most electronic structure calculations we are usually trying to calculate the molecular orbitals. How do we go about this We must remember that for many-body problems there is no correct solution we therefore require some means to decide whether one proposed wavefunction is better than another. Fortunately, the variation theorem provides us with a mechanism for answering this question. The theorem states that the... 

The claims for discovery and the naming of Element 104 are still in question. The Berkeley group proposes for the new element the name rutherfordium (symbol Rf), in honor of Ernest R. Rutherford, a New Zealand physicist. Meanwhile, the International Union of Pure and Applied Physics has proposed using the neutral temporary name, unnilquadium. 

The need for a calculated baU-size feed distribution is open to question however, methods have been proposed for calculating a rationed baU charge [Bond, Trans. Am. Inst. Min. Metall. Pet. Eng., 153, 373 (1943)]. 

Table A.4, taken from the CCPS Guidelines for Chemical Reactivity Evaluation and Application to Process Design, shows the questions which need to be asked regarding the safety of the proposed reaction, the data required to answer those questions and some selected methods of investigation. The experimental analysis is extremely specialized, and companies should consider outsourcing the tests if they do not have specialists in this area.

One easily overlooked question to ask when selecting a toller is, What other materials will be handled and what other processes will be operated concurrently with our proposed toll The answers may... 

The original proposal stimulated eonsiderable interest. However, beeause tliis was a new applieation for tliis type of faeility, it also raised several questions. Again, previous applieations for expander-driven... 

As w as mentioned earlier, extra rows are provided as can be seen in Figure 1. This gives extra flexibility needed for process design case studies. Often, the set of case studies initially envisioned by the engineer or manager are not sufficient to answer all questions. The extra rows allow intermediate recycles or intermediate flows from or additions to the plant that might not have been envisioned initially. Another value of the intermediate rows is to provide component values at intermediate points in the process. The breakeven value of a proposed purchase stream from another plant would be one use of intermediate component values. 

Figure 1 determines the foregoing temperature effect and is easier to use than the equation or a nomograph proposed by Kharbanda for this relation. The results are fairly accurate, provided the temperatures for which the surface tensions are considered are not close to the critical temperature of the material in question. Best results are obtained for nonpolar compounds. 

The guidelines presented are simplified and may not be sufficient for all applications. This does not mean that an axial cannot be used, because the vendors can perform a much more complex analysis and change factors that this simplified method chose to hold constant. Undoing some of these values is probably beyond the scope of most of the users. The best way to interpret a potential application is that an extra measure of care might be exercised when going out for bid. This can generate additional questions concerning the vendor s proposal. 

The specification and the proposal should be reviewed in depth. Options and their cost should be covered. Completeness is important because it is now time for the vendor to commit to any remaining items. If there was a single vendor in the lead, then, once the open questions are resolved, it would be safe to place the order. If, at the meeting, all questions were settled in a satisfactory manner, it can be quite good psychologically to place the order on the spot. 

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