These girl names were at the top of their popularity during 1970-1979 (usage of 0.322%) and have become much less widespread since (usage 0.14%, down 56.5%), with the form Jolene becoming less fashionable. Shown below is an analysis of the popularity of the girl name Jolena and affiliated names.hese girl names were at the top of their popularity during 1970-1979 (usage of 0.322%) and have become much less widespread since (usage 0.14%, down 56.5%), with the form Jolene becoming less fashionable. Shown below is an analysis of the popularity of the girl name Jolena and affiliated names.
Groups further define the hazard in Class I and Class II areas. In Class I, there are Group A (Acetylene and similar gases), Group B (Hydrogen and similar gases), Group C (Ethylene and similar gases) and Group D (Propane and similar gases). Hazardous dusts and fibers (Class II & III respectively) are not treated in Article 505.
Alkanes, Alkenes & Alkynes. Alkanes, alkenes and alkynes are simple hydrocarbon chains with no functional groups. Alkanes are identified because the carbon chain has only single bonds. Common alkanes include methane (natural gas), propane (heating and cooking fuel), butane (lighter fluid) and octane (automobile fuel). Alkenes have at least one double bond and alkynes have at least one triple bond. The most common alkyne is ethyne, better known as acetylene. The generic formula for alkanes is C n H 2n+2, where n is the number identified by the prefix. Alkenes have the formula C n H 2n and alkynes use the formula C n H 2n-2.