(See dichroism for the etymology of the term.). Dichroic filters can filter light from a white light source to produce light that is perceived by humans to be highly saturated (intense) in color. Although costly, such filters are popular in architectural and theatrical applications.
Russia constitution chapter 4 article 81 : 3. âOne person may not hold the position of Russian president for more than two terms in a row.â. So Putin had two terms between 2000 - 2008 and third term from 2012 till 2018. If you ask why 6 years in 2012 instead of 4 - terms were extended from four to six years in 2008, during Dmitry Medvedev's presidency.
Currently, the president can only serve two terms of four years. When Franklin D. Roosevelt was president, there was no limit on how many terms the president could serve. But in 1951, an amendment was added to the US Constitution limiting the president to only serving two terms. This source has the whole text of the US Constitution.