many mobile and off-grid devices include electronics and other electrical consumers like servo drives, which need a quite low supply power. since the price for photovoltaic modules drops continuously, photovoltaic power supply is interesting in more and more applications. in solar powered systems, a battery is needed to store energy for the night and cloudy periods. the power electronics of suc...

Background and Aims: Natural gas is one of the most important energy sources used today in urban communities as cheap and hazardous energy. In this regard, if the government and organizations do not pay attention to the proper infrastructure for gas installations, it will create irreparable risks for that society. The assessment and management of crisis in the various processes can play a key r...

Introduction: The development of residential and industrial areas has led to increasing gas consumption and overcrowding in gas supply networks. Accordingly, hazards and risks caused by human errors, processing and mechanical failures in pipelines, and gas leaks are on a rise. Several techniques have been so far proposed for identifying and controlling human errors. The main purpose of this stu...

this experimental study has been conducted to test the effect of oral presentation on the development of l2 learners grammar. but this oral presentation is not merely a deductive instruction of grammatical points, in this presentation two hypotheses of krashen (input and low filter hypotheses), stevicks viewpoints on grammar explanation and correction and widdowsons opinion on limited use of l1...

there is no doubt that human being needs to become integrated with industry and industry needs to be progressed, daily. on the other hand, serious events in industrial units specially in oil industries has been shown that such damages and events are industry related ones. the consequence of such events and damages which resulted in chemical and poisoned explosions and loss of life and property ...

the effect of poss instruction in comparison with conventional instruction on development of esp learners’ parts of speech knowledge and attitude toward call.