the growth rate and uniformity of carbon nano tubes (cnts) based on chemical vapor deposition (cvd) technique is investigated by using a numerical model. in this reactor, inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as  carrier gas enters into a horizontal cvd reactor at atmospheric pressure. based on the gas phase and surface reactions, released carbon...

resources’ scarcity, especially in developing countries, has caused allocation essentially among competing activities to create value. the importance of resource allocation would be more understood if we pay attention to growing complexity in societies and economic development problems they face. in the context of the national economic development literature, the notion of “key or critical sect...

existence of heavy minerals in waters in some regions causes serious environmental pollution and affects the soil and water resources quality. soil and waters sensitive to pollutants were investigated in this research, based on the degree of sensitivity of their parameters. the samples obtained from industrial and agricultural areas for identifying water tables at higher risk and display region...

there are several methods for analysing the behaviour of underground structures under different loading conditions. most of these methods have many simplifications; therefore, in some cases, the results are too conservative and a very high safety factor, usually of more than 2 is needed. on the other hand, for stability analysis and the designing of support systems, these methods consider segme...