thermal barrier coatings (tbcs) are used to provide thermal insulation to the hot section components of gas turbines in order to enhance the operating temperature and turbine efficiency. hot corrosion and thermal shocks are the main destructive factors in tbcs which comes as a result of oxygen and molten salt diffusion into the coating. in this thesis atmospheric plasma spraying was used to dep...

in this thesis, we consider a mathematical model of cancer with completely unknown parameters. we study the stability of critical points which are biologically admissible. then we consider a control on the system and introduce situations at which solutions are attracted to critical points and so the cancer disease has auto healing. the lyapunov stability method is used for estimating the un...

fuzzy logic has been developed over the past three decades into a widely applied techinque in classification and control engineering. today fuzzy logic control is one of the most important applications of fuzzy set theory and specially fuzzy logic. there are two general approachs for using of fuzzy control, software and hardware. integrated circuits as a solution for hardware realization are us...

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...

the current study examined iranian undergraduate efl students’ willingness to communicate with regard to their vocabulary knowledge. in general, participants were somewhat willing to communicate in english. the total mean score of 730 university students’ perception of willing to communicate was 83.53 out of 135. results, regarding four parts of willingness to communicate, revealed that part...

abstract: advertisements are the most accessible type of authentic materials, and this is one reason why they are used more and more in english teaching classes. for this cause, studies in the field of advertisements are very widespread nowadays. for pun is one aspect which makes advertisements more interesting, it is used more than before in advertisements. use of puns makes an advertisement m...

هدف تحقیق حاضر بررسی تاثیر نشانه های فرا گفتمان متنی بر فهم متون انگلیسی به وسیله ی زبان اموزان فارسی زبان است.این تحقیق علاوه بر این کوشیده است تا میزان اگاهی این زبان اموزان و نحوه ی تعامل انان را با متون خوانده شده در زبان انگلیسی به وسیله ی پرسش نامه ی تهیه شده بررسی کند.بر اساس محتوای یک متن انگلیسی یازده سوال درست /غلط طرح گردید و یک مرتبه با ان متن و یک مرتبه با نسخه ای که نشانه ها...

dynamic assessment according to vygotskys sociocultural theory, states that instruction and assessment are interrelated. using static forms of assessment with second and foreign language students could do more harm than good. many teachers neglect to take account of the complexity involved in learning a second or foreign language and often wonder why learning of a language take so long. thi...

nowadays enhancing critical thinking in learners is considered one of the foreign language teachers’ tasks due to its high position in foreign language classrooms. when it comes to selecting materials for language classrooms, there are obviously some criteria that teachers should apply. the present study aimed at a critical thinking based analysis of ten picture story books and ten folktales th...

writing as a productive skill requires practice in the basic sub-skills of vocabulary and grammar. in fact, grammar has been viewed as the core of programs in writing classes to help the students put the elements of sentence together and combine sentences of specific lengths to come up with an error-free work of art. conceptualizing l2 writing in this way introduces writing as a product and enc...