addAlias('joule'); $joule->addAlias('joules'); static::addUnit($joule); static::addMissingSIPrefixedUnits( $joule, 1, '%pJ', [ '%Pjoule', '%Pjoules', ] ); // Electronvolt $ev = UnitOfMeasure::linearUnitFactory('eV', 1.6021766208e-19); $ev->addAlias('electronvolt'); $ev->addAlias('electronvolts'); static::addUnit($ev); static::addMissingSIPrefixedUnits( $ev, 1, '%peV', [ '%Pelectronvolt', '%Pelectronvolts', ] ); // Watt hour $wattHour = UnitOfMeasure::linearUnitFactory('Wh', 3600); $wattHour->addAlias('watt hour'); $wattHour->addAlias('watt hours'); static::addUnit($wattHour); static::addMissingSIPrefixedUnits( $wattHour, 1, '%pWh', [ '%Pwatt hour', '%Pwatt hours', ] ); // Calorie $calorie = UnitOfMeasure::linearUnitFactory('cal', 4.184); $calorie->addAlias('calorie'); $calorie->addAlias('calories'); static::addUnit($calorie); static::addMissingSIPrefixedUnits( $calorie, 1, '%pcal', [ '%Pcalorie', '%Pcalories', ] ); } }