a phase-locked loop (pll) based frequency synthesizer is an important circuit that is used in many applications, especially in communication systems such as ethernet receivers, disk drive read/write channels, digital mobile receivers, high-speed memory interfaces, system clock recovery and wireless communication system. other than requiring good signal purity such as low phase noise and low spu...

Background and objectives: Mineral exploration is an important factor in rangeland ecosystem degradation in Iran. The first priority in mine site restoration is to use native plants as they can resist the stress caused by heavy metals and nutrients deficiency and also the harsh environmental situation. Vegetation restoration in polluted mining area depends on how plants can respond to phisycal ...

The functional properties of a plant can link the plant physiology with community and ecosystem processes. Thus it provides an appropriate tool for investigation of environmental changes and biodiversity. For this purpose, Zeiar rangeland of Damavand Mountain were selected as the 6000ha study area​​. A stratified-random sampling method was used for the sampling of vegetation and soil. Topograph...

this study examines the effetivenss of task-based activities in helping students learn english language structures for a better communication. initially, a michigan test was administered to the two groups of 52 students majoring in english at the allameh ghotb -e- ravandi university to ensure their homogeneity. the students scores on the grammar part of this test were also regarded as their pre...

in solvo-hydrothermal method, xrd pattern was indicated presence of intermediate of ammonium octatmolybdate and ammonium tetramolybdate, which were changed to stble phase of ?-moo3 annealing. sem images were indicated nanoparticle with semispheical morphology and tem image was demonstrated nanoparticles with a diameter size of 25nm. also in impregnate method. the xrd pattern was shown high crys...