the shape of a solar collector is an important factor in solar-to-thermal energy conversion. conical shape is one of the stationary and symmetric shapes that can be employed as a solar water heater. flow rate of working fluid on the solar collector has an important effect on the efficiency of the collector. the present study is an experimentally investigated of the performance of the solar coni...

background and objective : a considerable amount of sulfur hexafluoride is applied to evaluate the performance of each laboratory hood according to ashrae–110-95 method. sf 6 is extremely hostile to environment and expensive. in present work, the possibility of conducting this method of hood performance test with less volume of sf 6 was investigated. material and methods : the performance of a ...

in this paper, the flow of couple stress fluid is investigated in a helical screw rheometer (hsr). by unwrapping the channel, lands, and the outside rotating barrel, the geometry of hsr is approximated as a shallow infinite channel. both one- and two-dimensional analysis of the problem is presented using rectangular coordinates. in either case an exact solution of the flow problem is presented ...

treatment of acute asthma is based on rapid reversal of bronchospasm and arresting airway inflammation. this study was done to determine the effect of intravenous mgso4 for improvement of pulmonary fuction in patients with acute asthma non-responding to routine therapy. this randomized, double –blind controlled study was conducted on 48 patients, magnesium sulfate group , n=48 aged 12-85 years,...

the adsorption of lead (11) and copper (11) in a fixed bed column using activated carbonprepared from nipa palm nut was investigated. thomas model and yoon and nelson kinetic models were used to analyze the column performance. the rate constant for thomas model increased with increase in flow rate and initial ion concentration but remained constant at varying bed height. adsorption capacity for...

the existing studies of threshing process of combine harvesters adopt the assumption of constant mass, which is contradictory to the phenomenon of separation of grains and short stalks in actual threshing process. therefore, the characteristics of threshing and separation are not accurately described. aiming at this problem, this study established the tangential-longitudinal threshing and separ...

hydraulic fracturing in the fractured reservoirs plays a significant impact on the production rate. in this study, the hydrostatic condition is taken into account, the hydraulic fracturing operation was applied in every direction usinga written distinct element code. in each direction the hydraulic fracture is applied with different lengths and in each level the amount of production is predicte...

in this paper, the effect of flow rate on relative permeability curves was investigated in iranian carbonate rocks. core samples were prepared from outcrop of asmari formation. the dynamic displacement experiments were performed at 2.55, 3.55, 4.55 and 5.55 cc/hr during waterflooding and oilflooding. relative permeabilities have been calculated with the jones and roszelle method and then the fl...