a simple, sensitive and selective method for solvent extraction and spectrophotemetric determination of lanthanum (ii) europium (iii), and cerium (iii) is described , the rare earth metals are extracted into chloroform solution of n-phenylbenzohydroxamic acid (pbha) at ph 9-10 various parameters are studied to optimize the extraction conditions. the molar absorptivity is found to increase from ...

all analytical methods are generally based on the measurement of a parameter or parameters which are somehow related to the concentration of the species.an ideal analytical method is one in which the concentration of a species can be measured to a high degree precision and accuracy and with a high sensitivity. unfortunately finding such a method is very difficult or sometimes even impossible.in...

anxiety is one common disorder during childhood. in curing anxiety disorders, there are different types of psychological remedies, pharmotherapy, family therapy, and music therapy that can improve the individual’s anxiety, but we need some other remedies to improve social and emotional relationship and interactions. considering the importance of curing the anxiety disorders, the effect of sand ...

this work is presented in five parts. in the first part preparation of the starting complex [pt(c^n)cl(dmso)], 1, in which c^n = n(1),c(2?)-chelated, deprotonated 2-phenylpyridine, and dmso = dimethylsulfoxide, and its reaction with 1 equiv of the biphosphine ligands bis(diphenylphosphino)amine, dppa, or bis(diphenylphosphino)methane, dppm, to give the complex [pt(c^n)cl(dppa)], 2, or [pt(c^n)c...

the following null hypothesis was proposed: there is no significant difference between the efl students listening comprehension development receiving pictorial cues and those receiving no cuse. to test the null hypothesis, 52 male and femal freshmen students of medicine studing at iran university of medical scinces were randomly selected from a total population of 72 students. to ensure that th...

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 ...

due to the limiting workspace of parallel manipulator and regarding to finding the trajectory planning of singularity free at workspace is difficult, so finding a best solution that can develop a technique to determine the singularity-free zones in the workspace of parallel manipulators is highly important. in this thesis a simple and new technique are presented to determine the maximal singula...

cognitive studies of translation process have recently been awarded a great deal of attention. there exists a psychological angle to almost all translation activities. the present study, thus, deals with analysing the relationships between iranian prospective translators tolerance for ambiguity (ta) and their willingness to translate (wtt). the research was conducted as a mixed methods study, d...

during the process of reading, sometimes learners use ineffective and inefficient strategies and some factors may influence their use of strategies. perhaps critical thinking is one of these factors. this study aims to identify those categories of reading strategies that are mostly used by iranian efl learners and to see if there is any significant relationship between the critical thinking abi...

the major aim of this study was to investigate the relationship between social and cultural capital and efl students’ critical thinking skills. this study takes this relationship in to account to see if people with different sociocultural status are different regarding their critical thinking skills. to this end, 160 university students majoring in english language and literature, english trans...