With the knowledge of bill of materials (Table 3) and labor hours (Table 4), the total cost for. manufacturing the steel vessel is calculated and summarized in Table 5. Given that the steel vessel. has a storage capacity of 564 kg of CGH2, its cost is $539 per kg of stored hydrogen.
Prehistoric (Archaeological) & Historic Periods. The Prehistoric Period consists of time periods in the origin and evolution of humankind from about 2.5 million years to about 900 BCE. the Prehistoric Period is divided into the Archaeological Periods of the Stone, Bronze and Iron Ages.
prehistoric If while hiking, you see strange painting on a cliff, it may be rock art from prehistoric times, meaning something from the time before history was recorded. When you break down the word prehistoric, itâs easy to figure out what it means. The prefix pre-, means âbeforeâ and historic relates to something from a past culture. Put the two together, and you get prehistoric, a word that describes something that comes from a time before history was recorded. For example, Stonehenge is a prehistoric site, or the woolly mammoth is a prehistoric beast.