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...

‏‎the main purpose of this research was to:1.develop a coking model for thermal cracking of naphtha.2.study coke inhibition methods using different coke inhibitors.developing a coking model in naphtha cracking reactors requires a suitable model of the thermal cracking reactor based on a reliable kinetic model.to obtain reliable results all these models shall be solved simultaneously.for this pu...

the study of air infiltration into the buildings is important from several perspectives that may be noted to energy and design of hvac systems, indoor air quality and thermal comfort and design of smoke control systems. given the importance of this issue, an experimental and numerical study of air infiltration through conventional doors and windows has been explored in iran. to this end, at fir...

this study attempts to investigate the effect of peers’ revision in comparison to that of the teacher, and whether peers’ comments and teachers’ comments facilitate students’ revision? if yes, which one is more effective? also attempts have been made to see which aspects of language are more highlighted by peers versus teachers when commenting. besides, it is investigating the student’s attitud...

the purpose of the present study was to investigate the effect of task-based instruction of vocabulary on the receptive and oral productive acquisition of english vocabulary and compare the results with those obtained from the traditional method. the method and procedure applied in this study was as follows: after the implementation of opt, a group of sixty female students were chosen. the stu...

after test and review results and analysis of farm data, the following results were obtained. the review examined farms was done and the results obtained in this study was to determine the effectiveness of vaccines hatchpak avinew (frozen) and hatchpak ib h120 with spray in broilers a day in factories incubation and at least,they can be as vaccines avinew and bioral h120 ability to create saf...

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

the world wide web becomes very popular recently and plays an influential role in english learning. by burgeoning role of source-based writing as partial fulfillment of tefl courses and vast use of the internet, lack of empirical studies to explore these areas is obvious. this study aimed to explore the effect of the amount of familiarity with the web (internet literacy) on junior english stude...

nowadays, technical terminology translation plays an important role in human life. specific groups of people all over the world refer to learn these terminologies in order to be familiar with a subject and improve their knowledge in that domain. on the other hand, saving the technical translation equivalent is a particularly salient challenge for technical translators. the present study was con...

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...