In this study, optimum combinations of available rainfall gauging stations are selected by a model which is consist of geo statistics model as an estimator  and an optimized model. At the  first,  watershed  is  approximated  to  several  regular  geometric  shapes.  Then  kriging calculates  the  variance &nbs...

Irrigation water is limiting for crop production in arid and semi-arid areas. Furthermore, excess nitrogen (N) application is a source of groundwater contamination. Partial root drying irrigation (PRD) can be used as water saving technique and a controlling measure of groundwater N contamination. The objectives of this investigation were to evaluate the effect of ordinary furrow irrigation (OFI...

this new method which is worked out in isfahan university of technology, makes it possible to analyze the phases quantitatively in minerals and powdered materials by x ray diffraction and without any reference material. to identify n unknown phases, n different combinations of phases, from fine and coarse fractions, or etc., must be obtained. amorphous phases should not exist. intensity ratios ...