The efficiency of transmitting electrical energy from tree phase source is very complicated and expensive. In the same time, it known that active transmitted a to load does not come back source. If this so, then why in all devices systems for transmission electricity, one uses more than wire? “It shown any system can be made using one-wire method”. main results were received by several inventio...

4.2 Acid Deposition Acid rain was first identified in the 19th century, when English pharmacist Robert Angus Smith measured high acidity levels in rain falling over industrial regions of England and much lower levels in less-polluted areas near the coast. However, this pattern did not receive sustained attention until biologists began to notice sharp declines in fish populations in lakes in Nor...

Two powerful and related trends in the organization of U.S. farming are: production is shifting to larger family farms and agricultural contracts are increasingly being used to guide the production and marketing of farm commodities. These combined structural changes affect productivity and costs in agriculture and in the broader food sector, and also affect the financial returns to farmers, ben...