National identification number "Teudat Zehut"), bearing an Identity Number, is issued to all residents over 16 years old who have legal temporary or permanent residence status, including non-citizens. Japan's national identification number system, known within the country as "My Number" (Japanese: マイナンバー), went into effect from 2016. The number consists of 12 digits, and one is assigned to each resident of Japan, including non-Japanese long-term residents with valid residency permits. In Kazakhstan there is a 12-digit Individual Identification Number for natural persons (abbreviated in , "ZhSN"; in , "IIN", with first six digits representing person's date of birth in the YYMMDD format) and
Polystyrene sulfonate salt to prevent hypokalaemia, which is often associated with diarrhea. Polystyrene sulfonic acid, the acid whose salts are the polystyrene sulfonates, has the idealized formula (CHCHCHSOH). The material is prepared by sulfonation of polystyrene: Several methods exist for this conversion, which can lead to varying degree of sulfonation. Usually the polystyrene is crosslinked, which keeps the polymer from dissolving. Since the sulfonic acid group (SOH) is strongly acidic, this polymer neutralizes bases. In this way, various salts of the polymer can be prepared, leading to sodium, calcium, and other salts: These ion-containing polymers are called ionomers. Double substitutions of the