Ad
related to: yttrium in air pollution ppt
Search results
Results From The WOW.Com Content Network
Yttrium is a chemical element; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". [8] Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free ...
Various governmental agencies involved with environmental protection and with occupational safety and health have promulgated regulations limiting the allowable concentrations of gaseous pollutants in the ambient air or in emissions to the ambient air. Such regulations involve a number of different expressions of concentration.
There are five types of air pollution dispersion models, as well as some hybrids of the five types: [1] Box model – The box model is the simplest of the model types. [2] It assumes the airshed (i.e., a given volume of atmospheric air in a geographical region) is in the shape of a box.
Air pollution can occur naturally or be caused by human activities. [4] Air pollution causes around 7 or 8 million deaths each year. [5] [6] It is a significant risk factor for a number of pollution-related diseases, including heart disease, stroke, chronic obstructive pulmonary disease (COPD), asthma and lung cancer.
The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), [1] are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals.
The air pollution generated in November 2024 in India and Pakistan was regarded by climate researchers as an unprecedented intensification of the region's annual pollution cycle. [2] NASA satellite imaging showed a continuous cloud of smog that extended across the majority of eastern and northern Pakistan, as well as northwestern India. [3] [4]
Yttrium hydroxide can be decomposed by heating. Firstly, basic yttrium oxide (YO(OH)) is formed, and when heating is continued yttrium oxide is obtained. Both yttrium oxide and yttrium hydroxide are easily soluble in strong acids to form corresponding yttrium salts. Yttrium chalcogenides Y 2 S 3, Y 2 Se 3, and Y 2 Te 3 are known. They can be ...
Yttrium-90 is produced by the nuclear decay of strontium-90 which has a half-life of nearly 29 years and is a fission product of uranium used in nuclear reactors. As the strontium-90 decays, chemical high-purity separation is used to isolate the yttrium-90 before precipitation .