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...

attempts have been made to study the thermodynamic behavior of 1,3 butadiene purification columns with the aim of retrofitting those columns to more energy efficient separation schemes. 1,3 butadiene is purified in two columns in series through being separated from methyl acetylene and 1,2 butadiene in the first and second column respectively. comparisons have been made among different therm...

this study investigated the effects of planning on second-language written production with regard to task type. the participants were 75 iranian learners of english as a foreign language attending a private foreign language institution. they were asked to complete two different types of writing tasks (expository writing task and argumentative writing task) in different planned conditions (indiv...

chapter i provides an overview of structural linguistics and touches upon the saussurean dichotomies with the final goal of exploring their relevance to the stylistic studies of literature. to provide evidence for the singificance of the study, chapter ii deals with the controversial issue of linguistics and literature, and presents opposing views which, at the same time, have been central to t...

let h be a separable hilbert space and let b be the set of bessel sequences in h. by using several interesting results in operator theory we study some topological properties of frames and riesz bases by constructing a banach space structure on b. the convergence of a sequence of elements in b is de_ned and we determine whether important properties of the sequence is preserved under the con...

this study is an outlook of iranians religious practices and customs in eras such as nasser one. it attempts to answer the main question, "religious practices and ceremonies in the society during naseri ruling" and other subsidiary questions with scientific and historical theories. iran was a traditional and religious community . people abided by their religious practices and duties within reli...

in his last years of life americans had almost forgotton steinbeck, and those who had not, occasionally criticized him for supporting and praising the u. s. military intervention in the vietnam war. althought ateinbeck incorporates different themes into his works, each one bears many signs of his concern and sympathy for america and the american common people in particular. steinbecks to a god ...

this study investigated how group formation method, namely student-selected vs. teacher-assigned, influences the results of the community model of teaching creative writing; i.e., group dynamics and group outcome (the quality of performance). the study adopted an experimental comparison group and microgenetic research design to observe the change process over a relatively short period of time. ...