Compulsory voting , 22 countries were recorded as having compulsory voting. Of these, only 10 countries (additionally one Swiss canton and one Indian state) enforce it. Of the 30 member states of the Organisation for Economic Co-operation and Development, 10 had forms of compulsory voting. These are the countries and sub-national entities that enforce compulsory voting: Countries that have compulsory voting by law but do not enforce it: Although voting in a country may be compulsory, penalties for failing to vote are not always strictly enforced. In Australia and Brazil, providing a legitimate reason for not voting (such as illness) is accepted.
Catalytic cycle Heck reaction show catalytic cycles. A catalytic cycle is not necessarily a full reaction mechanism. For example, it may be that the intermediates have been detected, but it is not known by which mechanisms the actual elementary reactions occur. Precatalysts are not catalysts but are "precursors" to catalysts. Precatalysts are converted in the reactor to the actual catalytic species. The identification of catalysts vs precatalysts is an important theme in catalysis research. The conversion of a precatalyst to a catalyst is often called catalyst activation. Many metal halides are precatalysts for olefin polymerization, see Kaminsky catalyst and Ziegler-Natta catalysis. The