Bottleneck finding

The cycle time for the sequence, tc..K.uJS, should be minimized to find the optimal sequence of batches for the UIS policy. The form of the objective function implies that the optimization of a schedule for UIS with minimum cycle time simply reduces to selecting any sequence of batches with slack times of bottleneck stage(s) set to zero. 

The Production of a surfactant is to be increased from 15,000,000 to 20,000,000 lb / yr. With many new processes and some older ones, the operators and engineers find they can increase the throughput in certain units but are prevented from increasing production because other steps are running at the highest possible rates. The latter steps are called the bottlenecks. The process engineer must determine how to remove the bottlenecks from the process. 

Polymorphisms were much more frequent in individuals whose ancestors came from Africa rather than from other continents. This finding is in keeping with previous studies (e.g., Zietkiewicz et al., 1997). It supports the idea that non-African populations originated from Africa and on emigration in prehistoric time were subject to a population bottleneck. ... 

The Co/Mn/Br now eliminates the bottleneck caused by the presence of Co(in)s. The steady state concentration of Co(III) is also much lower caused by its rapid reduction by Mn(II). This reduces carboxylic acid decomposition. We have measured the rate of Mn(III) oxidaion of bromide in the presence and absence of p-xylene and do not find any difference in rate. Hence the system also eliminates the slow Co(III) + chlorotoluene reaction. This sequence of reactions is overall faster and more selective than either the thermal or cobalt catalyzed oxidation of m-chlorotoluene. 

E. Poliak In relation to the point discussed by Profs. Troe and Marcus, we have shown that those cases considered as saddle-point avoidance are consistent with variational transition-state theory (VTST). If one includes solvent modes in the VTST, one finds that the variational transition state moves away from the saddle point the bottleneck is simply no longer at the saddle point. 

By marrying molecular dynamics to transition state theory, these questionable assumptions can be dispensed with, and one can simulate a relaxation process involving bottlenecks rigorously, assuming only 1) classical mechanics, and 2) local equilibrium within the reactant and product zones separately. For simplicity we will first treat a situation in which there is only one bottleneck, whose location is known. Later, we will consider processes involving many bottlenecks, and will discuss computer-assisted heuristic methods for finding bottlenecks when their locations are not known a priori. 

So far we have considered a system with two reservoirs separated by one bottleneck in general a polyatomic system wil1 have many reservoirs in its configuration space, and the location of the critical bottleneck or bottlenecks will be unknown. Here we will first distinguish critical and rate-limiting bottlenecks from less important ones, and then discuss several more or less heuristic methods for for finding bottlenecks. 

If there is a bottleneck at r=30, the system is much more likely to find it and suddenly leak through if not, one has a least measured the equilibrium distribution of r in a region where it would be too low to measure directly. The normalizing factor Q/Q, necessary to make the connection between p and p, can found be from the histograms via eq. 20 or, more accurately, by eqs. 12a and 12b of reference 17. 

Before the development of the digital computer, the main weakness of transition state theory was its dependence on the harmonic approximation now its main weakness, and its main potential for future improvement, is in algorithms for finding bottlenecks. 

When the energy surface is smooth on a scale of kT, bottlenecks can be identified with saddle points, and the need is for an algorithm that, given a potential minimum, will find all the reasonably low saddle points leading out of it. Existing algorithms are unreliable in principle (because a saddle point may be invisible a short distance away), but may be reliable in practice. More empirical testing of them is needed. ... 

Table I. outlines the steps for finding the bottleneck, evaluating the rate constant, and generating typical trajectories for infrequent events.

Escape from A and find bottleneck or saddle point ... 

Energy requirements are a world-wide problem. The bottleneck is the low efficiency in energy transfer, e.g. in cells for energy storage. New materials play a crucial role in trying to find solutions for these problems. 

Nowadays, glycerol finds application only for niche markets therefore the co-production of glycerine is becoming a burden for biodiesel producers and a bottleneck limiting the market of this biofuel. The economics of biodiesel depend heavily on using its co-product a high-value use for glycerol could reduce the cost... 

As mentioned in Section 10.2, saddle points on the potential energy surface frequently correspond to the transition states that constitute bottlenecks to reaction. Finding these saddle points can provide a remarkable level of information about the mechanism. Such information about TS structure is not readily available in direct form from experiment. Calculation is then highly complementary with experiment and can be used to confirm a predicted mechanism, cast insight into observed substituent effects, and so on. 

But most important, to avoid submission bottlenecks, a clear schedule allows other team members—proofers, printers, collators, IT, QA, etc.—to make certain they are prepared. If QA needs a three-day period to review, count back a week (their three days, and two more to correct any problems they find) from the planned duplication, assembly, and submission dates. 

The main aspect for monitoring intracellular components was to find the bottlenecks in cephalosporin synthesis. For this it was important to measure the activities of the relevant enzymes in the biosynthesis. After tests in the past [49, 51] and new investigations [22] it was known that the use of protease inhibitors in the disintegration buffer was necessary for routine analysis of activities in crude material. The expense for such measurements was very high and so the main point was the detection of ACVS- and IPNS-activity. But all other important activities were monitored as well. 

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