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 converter operated outside of this band. Under lean engine operation, the exhaust contains excess oxygen, and the reduction of is not favored. Under rich conditions, the excess fuel consumes all of the available oxygen prior to the catalyst, leaving only oxygen stored in the catalyst available for the oxidation function. Closed-loop engine control systems are necessary for effective operation of three-way catalytic converters because of the continuous balancing required for effective reduction and HC oxidation. The control system must prevent the reduction catalyst from becoming fully oxidized, yet replenish the oxygen storage material so that its function as an oxidation catalyst