Effect of hydrothermal treatment temperature of the properties of sewage sludge derived solid fuel| Promotion of renewable energy sources in the European Union| CFD simulation and optimization of very low head axial flow turbine runner| Enhancement and optimization mechanisms of biogas production for rural household energy in developing countries: a review| Predictive factors associated with solar energy development in Laikipia district Central Kenya| Wind turbine rotor simulation via CFD based actuator disc technique compared to detailed measurement| Combustion of pure, hydrolyzed and methyl ester formed of jatropha curcas lin oil| Biogas production in dairy farming in Indonesia: a challenge for sustainability