introduction: the process of urbanism in countries that are developing, like islamic republic of iran with increasing of the number and the size of cities and the fast accepting of population have been caused the forming of problems like an in-official economics and in-official settlement and was become creating high population in main and old places of city and increasing of air pollution and ...

in this research a flat plate solar air collector was investigated under direct solar radiation consisted of a slatted glass cover, perforated absorber aluminum sheets (porosity 0.0177, 0.0314 and absorber thickness of 2.5 mm). the effect of porosity on absorber efficiency of collector was evaluated. six levels of air mass flow rates (0.0056 to 0.0385 kg m-2 s-1) were adopted.average solar ener...

in many peoples’ minds, air pollution is associated with the contamination of urban air from automobile exhausts and industrial emissions. growing number of scientific evidence has indicated that in industrialized societies, air within buildings can be more seriously polluted than the outdoor air. in the last couple of decades, with the widespread availability of personal computers, mathematica...

the relationship between public health and urban planning is an innovative and important issue that it has prominent position in future urban planning. in this context, adverse air quality condition and air pollutant concentrations higher than the permitted limit set by the world health organization is considered as a threat to the health of citizens in big cities. according to result of air po...

The shape of the air flow in the interior is heavily influenced by the air distribution system and the way air enters and exits. By numerically simulating flow by computational fluid dynamics, one can determine the flow pattern and temperature distribution and, with the help of the results, provide an optimal design of the air conditioning system. In this study, a chamber was first constructed ...

frost is one of the atmospheric phenomena which seriously threaten crop production. it also causes numerousaccidents in mountainous roads. in this research the spatial synoptic classification ssc method was employed toclassify the type of air masses. for the classification, such meteorological data as: temperature, dew point, mean sealevel pressure, cloudiness, direction and speed of wind were ...

cement powder size classification efficiency significantly affects quality of final product and extent of energy consumption in clinker grinding circuits. static and dynamic or high efficiency air separators are being used widely in closed circuit with multi-compartment tube ball mills, high pressure grinding rolls (hpgr) and more recently vertical roller mills (vrm) units in cement plants to c...

Performance of a gas turbine mainly depends on the inlet air temperature. The power output of a gas turbine depends on the flow of mass through it. This is precisely the reason why on hot days, when air is less dense, power output falls. The objective here is to assess the advanced systems applied in reducing the gas turbine intake air temperature and examine the merits from integration of the ...

In this experimental study, the effect of creating an air jet inside the combustion chamber by establishing an air-cell inside of the piston body at different injection timings in a DI diesel engine has been studied at 2000 rpm and full load operation. The performed tests include studying the Soot and NOx emissions, combustion and performance parameters. The obtained experimental results show t...