Cyclicality profitability cycles

However, if chemicals are irredeemably cyclical, does that make commodity chemicals an unattractive business In our view, the key is to look beyond individual cycles, at the long-term profitability of the sector. This reveals a perhaps surprising judgment, in view of conventional wisdom about the sector s unattractiveness commodity chemicals have earned returns above their weighted average cost of capital (WACC) across a number of cycles, making it very different and a much better performer than most other commodity sectors. 

Cyclic Steady State (CSS) is a unique feature of periodic adsorption processes. It is defuied as a condition whereby the state at the end of each cycle is identical to that at its beginning. Within an engineering context, the theoretical determination of CSS for a given set of periodic conditirms is a key step towards the optimisation of adsorption processes. CSS determination computer simulation, however, is still one of the most challenging procedures for a process engineer to implement. Once achieved, the engineer is more readily able to maximise profit and minimise costs of the adsorption process. 

We need to split two waters per CO2 fixed, so we double this total to 12 protons, generating 3 or 4 ATP. Only 3 ATP are required per CO2 in the dark reactions, so we probably make a slight profit of just under 1 ATP per CO2 over that which is required. However, sometimes, some of the electrons from ferredoxin Eire fed back to cyt-bb/f, short-circuiting the Z-scheme. This generates ATP via the Q-cycle but no NADPH. This is called cyclic phosphorylation and enables the cell to make even more ATP, even when NADPH is not required (Fig. 13.11). Depending on the exact stoichiometry of the various complexes (still not nailed down completely), cyclic phosphorylation may be essential to satisfying the Calvin cycle s requirements. 

As in thermodynamics, many processes in engineering, economics, ecology, biology or agriculture rely on a closed production cycle so that e Y 0 (where non-exact differential form is marked by d). If we call the first path Y and the returning path C, the output of cyclic production leads to non-zero profit (P) which may be invested or saved (S) [336]. The concept of non-exact differential forms leads to the proper relation of so called neoclassical theory [312], i.e., Y-C=S. According to the laws of calculus [337] this solution may be... 

In later chapters the use of a fixed production cycle will be compared with non-cyclic production rules. To make a reasonable comparison possible, the optimal fixed production cycle has to be determined. Therefore the optimal values for the available capacity for all product types have to be determined, with respect to profit maximisation or cost minimisation. An important element in this optimisation is that the use of the machines can be improved by making the fixed cycle longer, but this has a negative effect upon the delivery times. In the following subsections the delivery times and the costs of the fixed cycle production rule will be analysed for three different service disciplines with different demand and service time distributions. 

In the Examples 5.1 and 5.2 the capacity restrictions were very tight. In order to see whether the differences in average costs also appear in the situation in which the capacity is rather loose, we will consider a third example. Therefore we take again Example 5.1, but now with an available capacity of 15 instead of 12. With one set-up every period, about 72 percent (10.75 out of 15) of the available capacity will be used. The cyclic rules w,- are not affected by the change in capacity, therefore (5.2.18) still holds and we can also use the same semi-fixed cycle. For the extended (x,7>-mle we used the same set of values for the pairs iXi,Ti) as in (5.2.20). Because it will not be very profitable to produce orders with a longer residual lead time, the penalty points for these orders have been decreased and after some trials we have found the following set of values for the penalty points ... 

Another factor affecting the cost of premiums is the underwriting cycle. This is a factor that employers have little control over. It is a cyclic period of time showing a predictable pattern of profit and loss for insurance companies. Competition drives insurers to repeat the pattern during phases of the cycle. Insurance rates are adjusted based on this cycle, the most recent premiums, investment income, and losses reported by the insurance companies. 

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