  Crushed stone, for example, has a density of 100 pounds per cubic foot (lb/ft3), which is 1600 kilograms per cubic meter (kg/m3), which is 1.6 metric tons per cubic meter. Packed earth is about 95 lb/ft3, or 1520 kg/m3.
Harvard Business Review. Harvard Business Review. The Harvard Business Review (HBR) is a general management magazine published by Harvard Business Publishing, a wholly owned subsidiary of Harvard University. It is published 6 times a year and is headquartered in Brighton, Massachusetts.
Nitrile butadiene rubber (NBR) is a family of unsaturated copolymers of 2-propenenitrile and various butadiene monomers (1,2-butadiene and 1,3-butadiene).itrile butadiene is also used to create moulded goods, footwear, adhesives, sealants, sponges, expanded foams, and floor mats. Its resilience makes NBR a useful material for disposable lab, cleaning, and examination gloves.