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.
The Paleolithic Era (or Old Stone Age) is a period of prehistory from about 2.6 million years ago to around 10000 years ago. The Neolithic Era (or New Stone Age) began around 10,000 BC and ended between 4500 and 2000 BC in various parts of the world.