a novel acrylic acid-functionalized fe3o4 magnetic nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperacid in chemical transformations. the structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (tem), thermogravimetric analysis (tga), and ft-ir...

the present study aimed to investigate the possible effects of focused highlighted error feedback on grammatical accuracy of writing among iranian intermediate efl learners. after selecting 52 homogenous participants from among 70 university students attending azad university of rasht and randomly dividing them into two intact groups of 26 students, the researcher exposed the participants of th...

this research is a study on indicators of listening instruction in iranian english as a foreign language (efl) curriculum at guidance school and high school educational levels. this thesis aims at determining: a) the indicators of listening instruction at guidance school and high school efl curriculum. b) the indicators of listening instruction in irans guidance school and high school efl curri...

any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

one of the most commonly used techniques to reduce the corrosion rate of rebar in concrete is addition substances named corrosion inhibitors into the concrete. corrosion inhibitor is chemical compounds that were added to concrete to prevent corrosion of steel in concrete. sodium nitrate is a type of anodic inhibitors that this study investigatesthe effect of this inhibitor on the properties of ...

the application of a comprehensive model of communicative language ability (cla) to language teaching and testing has always been an imperative in l2 education since hymess proposal of communicative competence in the 1970s. recent l2 research has clearly underscored the importance of sufficient pragmatics representation as an essential component of cla in pedagogical and testing practices in l2...

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

the purpose of this study was to investigate the relationship between family functioning and marital adjustment humor couples are due to the nature and objectives of the research and application of methods for its implementation correlation was used. the study population consisted of all the couples in the city who uses random cluster sampling of 200 students were selected as sample. data from ...

in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...