The high-frequency performance of the reflector antennas is mainly limited by the surface. It has been shown that distortions on different regions of the reflector surface can have different effects on the radiation performance. In other words, degradation of the radiation pattern due to the presence of surface distortions is sensitive to the location and behavior of the surface distortion prof...

mineral dust is produced from both natural and anthropogenic sources. dust aerosols can be transported over long distances in the atmosphere. they reduce the incident shortwave radiation to the surface by absorbing and scattering the solar radiation; thereby leading to a cooling effect at the surface and lower tropospheric temperature. on the other hand, by absorption and re-emission of longwav...

1. introduction the process by which the net radiation is transformed to the atmospheric dynamical energy, occur to a large degree at the interface between the surface and the atmosphere. as the driving force for such process, an accurate estimation of the net radiation at the earth’s surface is a necessary input for surface process models. net radiation is a key component in the surface radiat...

Introduction: Megavoltage X-ray beams are used to treat cervix cancer due to their skin-sparing effect. Preferably, the radiation surface doses should be negligible; however, it increases due to electron contamination produced by various field parameters. Therefore, it is essential to provide proper knowledge about the effect of different field parameters on radiation doses. This study sought t...

nowadays two important discussions in academic parties all over the world are energy crisis and environment crisis. one of the strategies to deal with these crisises is using clean, renewable and domestic energy sources. one of the best renewable energies that can be used in different scales is solar energy. in iran which is considered among the greatest countries that receive huge amount of so...

The influence of microwave treatment on the surface roughness, hydrophobicity, and chemical composition of galena was studied. The pure galena specimens and purified galena concentrate were used in this work. A conventional multi-modal oven (with a frequency of 2.45 GHz and a maximum power of 900 W) was used to conduct the experiments. The results obtained from the atomic-force microscopy analy...