telephone retardation coil
1History of electromagnetism — The history of electromagnetism, that is the human understanding and recorded use of electromagnetic forces, dates back over two thousand years ago, see Timeline of electromagnetism. The ancients must have been acquainted with the effects of… …
2Health and Disease — ▪ 2009 Introduction Food and Drug Safety. In 2008 the contamination of infant formula and related dairy products with melamine in China led to widespread health problems in children, including urinary problems and possible renal tube… …
