  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.
Citalopram HBr (Celexa) is a Class C drug. There are no adequate studies of pregnant women using this drug. It should be used during pregnancy only if the potential risk to the fetus is outweighed by the benefit to the mother. Celexa is excreted in breast milk.