factor  is introduced for direct head loss calculation and sizing in dual-diameter laterals of sprinkler and trickle irrigation systems when the hazen-williams equation is to be applied. application of this factor prevents trial and error and uses fewer head-loss equations in calculating the total friction loss and designing dual-diameter laterals. the proposed factor is a function of total num...

in most industrial zones, electric energy is one of the most important energy sources. since electrical motors are the main energy consumers of industrial factories, consumption optimization in these motors can be considered as a main option related to energy saving. one very effective way to reduce the consumption of these equipment is to use a motor speed controllers or drives. since the loss...

the networked control system in modern control widely uses to decrease the implementation cost and increasing the performance. ncs in addition to its advantages is inevitable. nevertheless they suffer of some limitations and deficiencies. packet loss is one of the main limitations which affect the control system in different conditions and finally may lead to system instability. for this reason...

objective: generated acoustic trauma by suction and drill may cause sensorineural hearing loss after tympanomastoid surgery. this study was carried out to determine the relationship of sensorineural hearing loss and chronic otitis media surgery at ahvaz jundishapur university of medical sciences in iran. material and methods: this prospective study included 386 patients of chronic middle ear di...

background: obesity and diabetes are the most important problems of public health. evidence from molecular animal research and epidemiologic investigations indicate that calcium intake may have an influence on body composition, weight and insulin resistance. the objective of this study was to determine the effects of calcium supplementation on body composition, weight, insulin resistance and bl...

results the mean distances between the crestal bone and the implant shoulder in group 1 were 1.01, 1.44, and 1.93 mm at the implant placement time, and at the 6 and 12-month postoperative intervals, respectively. in group 2, these distances were 1.35, 1.20, and 1.41 mm, respectively. there were no significant differences in the marginal bone resorption between the two groups (p > 0.05). conclus...

since knowledge on hydrodynamic torque of a butterfly valve is very important for butterfly valve design, its hydrodynamic torque is investigated in this paper. in reality, the investigation of the loss coefficient and torque from some experiments will take a long time and a lot of money. this paper presents a statistical study of the flow past the butterfly valve in a static analysis using com...

sclerotinia stem rot (ssr), caused by sclerotinia sclerotiorum, is one of the most important diseases of canola (brassica napus) in golestan province, the leading canola producer in iran. in order to assess the yield loss of canola caused by ssr, 80 fields were surveyed in four different regions of the province (gorgan, ali abad, kalaleh and gonbad) during 2006-2007, and ssr intensity was recor...

one of the big concerns of big cities is facing with the increase of fossil fuel vehicles in the roads. the cars intensify greenhouse gas emission in civic centers. one approach to reduce the emission is replacing the cars by plug-in electric vehicles (pevs). in spite of reducing the emission, pevs have some adverse effect on electric distribution networks. technical challenges such as load and...

in mulberry orchards in northern part of iran, thrips is a dominant pest and causing a lot of damage to the mulberry. the effect of pest on bio-chemical parameters of mulberry leaf of two varieties viz. kenmochi and ichenoise and also the effect of feeding of infested leaves on rearing performances have been studied. for the study, six plots of 200 m2 area of both the varieties were selected an...