1) Many large-scale processes use holding tanks (which are sometimes referred to as surge tanks) to handle variations in flow rate. For example, the production of penicillin by fermentation using the mold Penicillium chrysogenum takes about 7 days in a large production-scale fermentor (basically a large tank). Seven separate fermentors are used, each started (and harvested) on a different day of the week. This involves pumping the contents of the fermentor into a large holding tank at a flow rate qin, with the liquid flowing out of this tank and into the rest of the penicillin process at a constant flow rate q. qin=3000t1/2qin=3000L/hrfor1hr