CO2 emissions, economic growth and energy consumption in Iran: A co-integration approach
Author(s)- Saboori.B, Soleymani.A
This study examines the dynamic relationship among carbon dioxide (CO2) emissions, economic growth and energy consumption based on the environmental Kuznets curve (EKC) hypothesis for Iran during the period 1971–2007. Auto regressive distributed lag (ARDL) methodology is employed as the estimation method. The results obtained suggest the existence of three forms of long-run relationship among variables when CO2 emissions, economic growth and energy consumption are the dependent variables. The results do not support the EKC hypothesis which assumes an inverted U-shaped relationship between income and environmental degradation. The long-run results indicate energy consumption has a positive and significant impact on CO2 emissions. The stability of the variables in estimated model is also examined. The result suggests that the estimated model is stable over the sample period.
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CO2 Emission as a result of the fuel consumption and tillage quality in different tillage conditions
Author(s)- Namdari M., Rafiee Sh., Jafari A.
Moldboard plow is the most common primary tillage implement, largest consumer of energy and a significant contributor to CO2 emission in agriculture. Operational variables in tillage could influence the environment and tillage quality. In the present study a field split-factorial experiment was conducted to examine the influence of soil water content, plowing depth and operating speed in tillage by moldboard plow on clod size, soil inversion, fuel consumption and CO2 emission as a result of the fuel consumption. Results showed plowing in moist of 15% formed clods significantly smaller than moist of 10% and increased soil inversion. A 33% increase in soil water content increased the fuel consumption and CO2 emission by 21.21% approximately. Effect of plowing depth on clod size, fuel consumption and CO2 emission were significant. Plowing at depth of 0.20 m significantly decreased clod size, fuel consumption and CO2 emission compared with plowing at depth of 0.25 m. The effect of plowing depth on soil inversion was not significant but decreasing plowing depth tends to increase soil inversion. Effect of operating speed on all attributes was significant. Increase operating speed from 3 to 5.5 kmh-1 decreased clod size, fuel consumption and CO2 emission as a result of the fuel consumption and increased soil inversion significantly.
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Carbon Dioxide as Natural Refrigerant
Author(s)– Padalkar A. S., Kadam A. D
The use of halogen based chemical compounds as refrigerant has compromised the existence of life on the earth. This fundamental paper discusses the suitability of natural refrigerant CO2 in refrigeration and air conditioning systems for high ambient climatic conditions encountered in India. The lower critical temperature of CO2 converts the subcritical vapour compression cycle to transcritical mode whenever the ambient temperature crosses the critical temperature of 31oC. The transcritical cycle gives lower cooling capacity and higher compressor power consumption which results in less energy efficiency of the system. The thermo-physical and transport properties of CO2 are much better than chemical refrigerants results in compact size of the system with competitive energy efficiency at lower ambient temperature. The matching of operation the transcritical air conditioning system with heating and cooling applications gives very high energy efficiency.
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