the narrow operating window between pore pressure and fracture pressure makes drilling difficult in some operations. a feasibility study of managed pressure drilling (mpd) is carried out on iran darquain oil field. the previous wells drilled in this field showed that mud returns were lost during drilling gadvan formation. the present work addresses this problem by means of surface back pressure...

introduction sustainability of agricultural systems may improve due to intercropping as a result of diversity increasing. marigold (calendula officinalis) is a major medicinal plant from asteraceae family, though weeds suppress it because of lower competitiveness against weeds. mungbean (vigna radiata) is a pulse crop from fabaceae family and is one of the major nutritive sources especially in ...

introduction weed infestation causes an extremely reduction of crops yield. on the other hand, increasing the diversity of crops in agro-ecosystems will change the biomass distribution of weeds community, thereby reducing the number and density of different weed species. weed management in the past few decades has been in conflict with ecological principles and sustainability of the production ...

Circulating microRNAs (miRNAs) were found to exist in serum/plasma in a highly stable, cell-free form, and aberrantly expressed in many human diseases. Currently, the expression levels of circulating miRNAs are estimated by quantitative real-time polymerase chain reaction. However, no study has systematically evaluated reference genes for evaluating circulating microRNA expression. This study d...

Incorrect evaluation of equivalent circulating density (ECD) while drilling oil and gas wells may result in problems such as lost circulation, kicks, differential pipe sticking etc especially narrow margins. Due to the incompressible nature liquids, increase wellbore pressure will only have appreciable effect on fluid rheology at higher pressures, whereas a small temperature cause decrease rheo...