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.
For the purposes of this article, Prehistoric Britain is Britain during the period between the first arrival of humans on the land mass now known as Great Britain and the start of recorded British history.lthough the first had been built about 1500 BC, hillfort building peaked during the later Iron Age. There are over 2000 Iron Age hillforts known in Britain. By about 350 BC many hillforts went out of use and the remaining ones were reinforced. Pytheas was quoted as writing that the Britons were renowned wheat farmers.