Zeotropic mixture harmful effects that hydrochlorofluorocarbons (HCFC) and chlorofluorocarbons (CFC) have on the ozone layer and global warming. Researchers have focused on using new mixtures that have the same properties as past refrigerants to phase out harmful halogenated substances, in accordance to the Montreal Protocol and Kyoto Protocol. For example, researchers found that zeotropic mixture R-404A can replace R-12, a CFC, in household refrigerators. However, there are some technical difficulties for using zeotropic mixtures. This includes leakages, as well as the high temperature glide associated with substances of different boiling points, though the temperature glide can be matched to the temperature difference
Radium, and other radioactive substances red glass windows while the disease went through certain stages. Radium, and other radioactive substances Radium, and Other Radio-active Substances; Polonium, Actinium, and Thorium is a book published in 1903 by William Joseph Hammer, when he was about 50 years old. The book is the text of a lecture delivered at a meeting of the American Institute of Electrical Engineers. The title of the lecture was "Radium and other radioactive substances with a consideration of phosphorescent and fluorescent substances. The properties and applications of selenium and the treatment of disease by the ultra violet light". The lecture was augmented by