in this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (gdl) of pem fuel cell is modeled. the governing equations including energy, mass and momentum conservation equations are solved by numerical methods. also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (gdl) thickness and inlet relative humidity are calculated...

this study was carried out in sorkhdeh rangeland in semnan province in order to determine the ecological species groups and their relationships with environmental factors as a tool for better management. vegetation sampling was performed in 230 plots under equal random classification method and soil samples were taken in 0-15 depth. climatic and topographic data were extracted by overlaying sam...

Annual and seasonal correlations between temperature and both specific and relative humidity are presented based on radiosonde station data over the tropical Pacific Ocean and North America. Results are presented for the surface and the 850-, 700-, and 500-hPa levels. The correlations between anomalies of temperature and relative humidity are generally negative, and those between temperature an...

Cupric oxide nanostructures were synthesized via a simple reaction between copper nitrate and sodium hydroxide using a sonochemical-assisted method. The synthesized CuO was then characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, ultraviolet-visible and photoluminescence spectroscopy. Our studies show that the CuO na...

The objective of this study was to evaluate the effects of relative humidity, light management, minimum ventilation rates, CO2 enrichment and canopy size on water consumption in three different greenhouse systems (conventional, open heat pump, and confined heat pump) in winter, spring, and summer months. Using different relative humidity set points resulted in almost the same relative humidity ...

abstract evapotranspiration as one of the important elements in agriculture has a considerable role in water resource management. therefore, using a more exact estimation method is an essential step of agricultural development, especially in arid semi-arid area. in this research, in order to exact estimate of garlic evapotranspiration using lysimeteric data, an artificial neural network (ann) m...

this paper discusses the results of the full-scale field measurement study to investigate the most efficient application strategy of the hybrid turbine ventilator (htv) in improving the indoor thermal comfort in hot-humid tropics. the effects of three different htv application strategies performance on improving the levels of indoor air temperature, relative humidity (rh) and air velocity were ...