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...

deployable scissor type structures are composed of the so-called scissor-like elements (sles), which are connected to each other at an intermediate point through a pivotal connection and allow them to be folded into a compact bundle for storage or transport. several sles are connected to each other in order to form units with regular polygonal plan views. the sides and radii of the polygons are...

the present dissertation aims to investigate four-word lexical bundles in applied linguistics research articles by iranian and internationally-published writers. the aims of this study are two-fold: first of all, attempts have been made to create a comprehensive list of the most commonly used four-word lexical bundles categorized by their type and token frequency, their structural characteristi...

with the increasing population and the need for more food, as well as with the development of science and technology, human approach to unnatural and often chemical inputs to increase agricultural production has been a great expansion and problems such as increased cancers, chronic diseases has created environmental pollution. implementation of organic organic is a solution to these problems . ...

Background and Objective: Various aspects including the environmental burdens, social and economic consequences of the waste management(WM) scenarios must be considered to come up with a comprehensive WM plan. Life Cycle Assessment (LCA) approach is a systematic method to quantify the environmental burdens of each WM scenario. Materials and Methods: This study used an LCA approach to develop a...

the effect of learning strategies on the speaking ability of iranian students in the context of language institutes abstract language learning strategies are of the most important factors that help language learners to learn a foreign language and how they can deal with the four language skills specifically speaking skill effectively. acknowledging the great impact of learning strategies...

abstract deviation or in other words committing a crime is literally a social problem. this research that was conducted in 1389 and 1390 has tried to investigate the causes of crimes committed by young male inmates qazvin central prison and effective variables on their tendency to deviation. accordingly after collecting theoretical framework and offering theoretical model including both hirsch...

the purpose of this thesis was to investigate how differently metacognitive, cognitive, and social/affective strategies affect l2 learners’ reading comprehension. to this end, the study employed a quasi-experimental design with a placement test as a proficiency test to find the homogeneity of groups. three classes were randomly selected as the experimental groups (n =90), and each class was tau...

in recent years many researchers have been focused on interaction of small molecules with dna. dna is generally the primary intracellular of anticancer drugs, so the interaction between small molecules and dna can cause dna damage in cancer cells, blocking the division of cancer cells and resulting in cell death. the flavonoids are a large group of polyphenolic natural products that are widely ...

according to webster and wind (1972) and anderson et al (1987), “organizational buying is a complex process and involves many people from different functional areas, multiple goals and potentially conflicting decision criteria. moreover, the customers of today are also more knowledgeable and selective when making their purchasing decisions. since a key to organizational survival is the retentio...