the effects of planting date and single irrigation (si) allocation scenarios on increasing and stability of yield were investigated to determine the total water productivity and economical water productivity (wpe), for rainfed wheat at dryland agricultural research institute in maragheh, iran, during 2000-2004. the treatments included three sowing dates (early, normal and late), four allocation...

A number n is said to be economical if the prime power factori-sation of n can be written with no more digits than n itself. We show that under a plausible hypothesis, related to the twin prime conjecture, there are arbitrarily long sequences of consecutive economial numbers, and exhibit such a sequence of length 9.

Collaborative Learning is emerging as an important learning method. Computer and network supported collaborative learning systems and environments are starting to appear. In order that these systems contribute positively into the educational process, it is important to consider quality requirements. This paper presents the CLE (Collaborative Learning Evaluation), a framework for evaluating Coll...

the present study attempts to analyze the evaluation of the central district of ravansar township rural community from the performance of village administrations (dehyari) by using of structural equation modeling (sem). in order to collect needed data, a questionnaire was designed and completed via interviewing the sample population. the observed variables for economical, socio-cultural, servic...