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This paper investigates the relation among energy production, CO 2 emissions and economic growth of Iran with additional variables such as domestic and foreign investment, inflation, population density and agricultural land. Annual time series data is used for the period of 1971–2011 according to data availability. Our main results are as: (1) there is long run relationship among the variables. (2) CO 2 emissions has positive relation with economic growth. (3) energy production has positive effect on the economic growth of Iran. (4) Domestic investment has more contribution than the foreign investment in the explanation of economic growth. (5) Speed of adjustment shows that system will move to equilibrium path quickly. Diagnostic tests confirm the perfectness of the model. DOLS and FMOLS shows the similar results. Further, variance decomposition and cholseky impulse response function also show similar findings. [ABSTRACT FROM AUTHOR]

Geothermal heat sources are promising renewable resources of energy. In this paper, a novel ammonia-water power cycle was designed considering the geothermal resources in Iran. This cycle was analyzed and the effects of ammonia fraction and boiler pressure on its performance were investigated. At the first, Sabalan geothermal field with temperature of 456K was studied. For this geothermal source, the effects of various ammonia fractions were perused in the boiler pressure of 25 bar. The results showed that the ammonia concentration of 0.855 led to the best performance. Also, investigating the boiler pressure at the constant concentration (0.855) indicated that the maximum efficiency happened at 35 bar. Based on genetic algorithm, the simultaneous effects of various concentrations and pressures on the performance of the ammonia-water cycle were surveyed and the optimum values were found for Sabalan source. So that, at the source temperature of 456K, the optimum concentration and pressure were obtained 0.85 and 36 bar, respectively. Finally, the optimum conditions for several geothermal source temperatures were presented within a table. Moreover, at the same sources, the presented optimized cycle was compared with other cycles in the literatures. The results indicated that the presented cycle at optimum conditions had higher efficiency. • Introducing an improved ammonia-water cycle in order to power generation by geothermal resource. • Energy and exergy analyses of the proposed cycle in details. • Optimizing ammonia concentration and boiler pressure in various temperatures of geothermal sources by genetic algorithm (GA). [ABSTRACT FROM AUTHOR]