a new sensitive and selective spectrophotometric method for the determination of iron using a pvc membrane containing bathophenanthroline and dioctylphethalate as the solid phase extraction medium is investigated. fe(ii) in an aqueous sample solution is trapped on the membrane with an anion species, picrate ion and forms a complex with bathophenanthroline. the absorbance of the red-orange membr...

statement of problem: periodontal disease (pd) has been linked to adverse cardiovascular events by unknown mechanisms. c-reactive protein (crp) is a prognostic marker for cardiovascular disease, with reported elevated serum levels during pd. purpose: the aim of the present study was to evaluate the association between pd and higher crp levels in the serum of acute myocardial infarction (ami) pa...

in this paper, a new topology is proposed for three-phase to single-phase matrix converters, where more voltage levels are produced in the output in comparison with the conventional topologies. in addition, a new control method based on minimum error between the generated and the desired output voltages is proposed for three-phase to single-phase matrix converters. in the proposed control metho...

in this research mass transfer coefficient under jetting regime in different directions (from dispersed to continuous and continuous to dispersed phase) has been studied using an experimental setup. n-butanol-succinic acid-water with low interfacial tension has been selected as experimental chemical system. the effects of various parameters such as jet velocity, nozzle diameter and the height o...

nano-sized titanium dioxide tio2 powder was successfully prepared from its precursor titanium (iv) chloride by a simple and new wet chemical method. ticl4 were used as precursor in hydrogen peroxide, h2o2 and ethanol. this solution was then peptized using nitric acid and heated under reflux at 80°c. their physico-chemical properties were then characterized by transmission electron microscopy (t...

multiphase flows are commonly encountered in oil and gas industries. the transport of multiphase flow causes the formation of slug, the increase of pressure drop and the possibility of phase changes therefore, a set of simulation runs was performed to predict flow regimes in a horizontal pipeline, and the results were compared with the baker chart. the effects of small downward inclinations of ...