In the present work, a new vertical cavity surface emitting laser (VCSEL) structure employing combined oxide layer and single defect photonic crystal index guiding layer has been investigated for L-band optical fiber application. The basic design goal was to obtain photonic crystal VCSEL (PhC VCSEL) with the high power, high slop efficiency and low threshold that operate at 1.55-1.6μm wavelengt...

The effect of solar radiation on thermal distribution in thin high arch dams is investigated. The differential equation governing thermal behavior of mass concrete in three-dimensional space is solved applying appropriate boundary conditions. Solar radiation is implemented considering the dam face direction relative to the sun, the slop relative to horizon, the region cloud cover, and the surro...

abstract: the dust is one of the weather phenomena that have negative environmental effects and consequences. the central city of ahvaz in khuzestan province is one of cities that in every year witnessed the dust in its environment. in this study, after determining that the dust phenomena data are abnormal, using the sen's nonparametric model been proceed to modeling of changes and survey ...

forest harvesting operations for extracting of forest products in these trails, causing extensive damage in a wide range of soil and its productivity every year, therefore it is necessary to research about degradation of soil properties should be down. the aim of this study was investigate changes in the skid trails soil physical characteristics due to wheeled cable skidder traffic by measuring...