flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

seismic retrofit strategies have been developed in the past few decades following the introduction of new seismic provisions and the availability of advanced materials and methods. it can be observed that new approaches to deal with more lateral forces are more innovative and more energy absorbent. in line with this, there is a growing trend toward the use of steel shear walls as a system with ...

abstract cooperative learning refers to small groups of learners working together as a team to solve a problem, complete a task, or accomplish a common goal. in a cooperative environment one’s success is directly related to the success of other members because the focus on the individual shifts towards the group. to test the effectiveness of the method, using jigsaw technique, a study was cond...

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...

this study was conducted to investigate the impact of podcasts as a learning and teaching tool on iranian efl learners’ motivation for listening as well as on their listening comprehension ability. the study also investigated the learners’ perception towards listening to podcasts and examined whether the learners were likely to accept podcasts. out of fifty-five intermediate learners studying e...

an investigation into oral interaction in language classes: a conversation analytic point of view the aim of this thesis is to analyze the interaction between language teachers and students in english language institutes. this work is done in the context of yasuj city. learning another language, which is in most cases english, involves many variables. one of these variables is the linguistic...

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

regarding the ever evolving and improving world on different aspects of knowledge, the need to a worldwide communication would emerge stronger than ever before which calls for special attention on the judgments and best choices for intermediating between the nations. as the language skills for translation are tested separately from translation skills themselves, to assess translation skills pro...

based on the latest records of typhlops vermicularis merrem, 1820 from iran, this species is distributed in the northern and southern regions of the country. in this study, new records of typhlops vermicularis are presented and it is shown that distribution range of this species is extended towards the eastern and western iran, and according to the new distribution map, it can be assumed that t...