Why Emissions Testing is Required Vehicle emissions testing is required in major metropolitan areas that are not meeting federal air quality standards for ozone and other pollutants. In Arizona, testing is required in the Phoenix and Tucson metropolitan areas, where ozone and particulate matter pollutio...
While some of these technologies have made great strides and led to cost savings and rapid market expansion, others still need further research before they can be applied in a commercial s etting4,5. Solar photovoltaic (PV) energy systems were first utilised in space, but they are now ...