A double pipe counter flow heat exchanger is to be designed to cool $$12000$$ $$kg/hr$$ of an oil of specific heat $$1.95$$ $$kJ/kgK$$ from $$\,85{}^ \circ C$$ to $$\,55{}^ \circ C$$ by water entering the heat exchanger at $$\,30{}^ \circ C$$ and leaving at $$\,45{}^ \circ C$$. If the $$OHTC$$ of heat exchanger is $$400$$ $$\,W/{m^2}K.\,$$ Calculate the $$LMTD$$ and the surface area of the heat exchanger

In the construction of networks, dummy activities are introduced in order to :

Service workshop has four jobs on hand to be processed. The date and processing time for each of the jobs are given below

Considering mean lateness and mean flow time, evaluate the shortest-time rule and least-slack rule and recommend the desirable rule.

The process of shot peening increases the fatigue life of steel springs mainly because it results in