In complex task domains, such as games, students may exceed their teachers. Such tasks afford diverse means to tradeoff one type of performance for another, combining task elements in novel ways to yield method variations and strategy discoveries that, if mastered, might produce large or small leaps in performance. For the researcher interested in the development of extreme expertise in the wil...

abstract: deficit irrigation technique can be used for produce more yield for every unit of irrigation water, and cause to increase crop economical benefit. main purpose of deficit irrigation is high water use efficiency with decreasing in irrigation sufficiency. in this research potential of cropwat model in deficit irrigation management for two crops, wheat and barley in karaj climate was stu...

the excessive biological sludge production is one of the disadvantages of aerobic process such as sbr. so the problem of excess sludge production along with its treatment , and disposal in aerobic processes in municipal and industrial waste water can be seen in many parts of the world even in our country . to solve the problem of excess sludge production , reducing in by oxidizing some of the s...

Nutrient depletion in soils adversely affects soil quality and reduces crop yield and consequently poses a potential threat to global food security and agricultural sustainability. With an emphasis on human-induced nutrient depletion, this paper described the causality among soil nutrient depletion, soil quality, crop production, socio-economic variables, and environmental condition. Then, glob...

      In order to study the effects of post-anthesis heat stress and nitrogen levels on grain yield and yield components of wheat genotypes, two separate field experiments were conducted in delayed and optimum sowing dates under Ahvaz conditions (2006-2007). The Ahvaz site located in south west of Iran (32°20' N, 40°20' E) with subtropical climate condition. The experiment site had a moderate w...