virtual learning is a type of electronic learning system based on the web. it models traditional in- person learning by providing virtual access to classes, tests, homework, feedbacks and etc. students and teachers can interact through chat rooms or other virtual environments. web 2.0 services are usually used for this method. internet audio-visual tools, multimedia systems, a disco cd-roms, vi...

virtual water adds a new dimension to crop trades and provides a new way of thinking about water scarcity. a systematic analysis of virtual water flows requires integration of all critical drivers of virtual water flows under a single consistent framework. the aim of this study was to assess virtual water flows related to trades of grain crops (wheat, corn, rice, and coarse cereals) and their i...

In this study, at the first stage, the rupture criterion of bubbles wall in Aluminum metal foam liquid was investigated by using Lattice Boltzmann. The two phases modeling were accomplished by using a modified Shan-Chen model. This model was run for several bubbles in A356+3wt.%SiC melt system. Then, bubbles morphologies (virtual metallographic) for A356+3wt.%SiC foams were simulated. Results s...

Information technology is one of the largest and most important human achievements in the present era whose influence on most human activities is undeniable. The traditional education system is being affected by the information technology and it is now turning into an electronic education system. One of the newest issues in the field of electronic education is the effects of web page a...