in the first chapter we study the necessary background of structure of commutators of operators and show what the commutator of two operators on a separable hilbert space looks like. in the second chapter we study basic property of jb and jb-algebras, jc and jc-algebras. the purpose of this chapter is to describe derivations of reversible jc-algebras in term of derivations of b (h) which are we...

in this thesis, structural, electronical, and optical properties of inverse pervskite(ca3pbo) in cubic phase have been investigated.the calculation have been done based on density functional theory and according to generalized gradiant approximate (gga) as correlating potential. in order to calculate the configurations, implementing in the wien2k code have been used from 2013 version. first of ...

abstract nowadays, the science of decision making has been paid to more attention due to the complexity of the problems of suppliers selection. as known, one of the efficient tools in economic and human resources development is the extension of communication networks in developing countries. so, the proper selection of suppliers of tc equipments is of concern very much. in this study, a ...

the purpose of this study is to investigate and explore the causes of identity crisis as one of the debilitating consequences of colonial project after the withdrawal of colonial power. in order to do justice to the full-length severity of displacement that was the fruit of indentureship, v. s. naipauls west indian epic, a house for mr biswas, has been scrutinized with the main focus being the ...

استافیلوکوکوس اورئوس نوعی کوکسی گرم مثبت است که یکی از عوامل تورم پستان در گاو می-باشد. اغلب مزمن بوده و با درمان آنتی بیوتیکی به آسانی درمان نمی شود لذا مشکلات جدی برای تولید شیر و صنعت لبنی ایجاد می نماید (sol, 1997). تورم پستان بیماری عفونی است که در بخش تولید با هزینه های بالای مالی درمان می شود. مقاومت دارویی در گونه های استافیلوکوکوس ارئوس مثل مقاومت به بتا لاکتام ها از جمله متی سیلین شنا...

power transformers are important equipments in power systems. thus there is a large number of researches devoted of power transformers. however, there is still a demand for future investigations, especially in the field of diagnosis of transformer failures. in order to fulfill the demand, the first part reports a study case in which four main types of failures on the active part are investigate...

abstract: mineral scaling in oil and gas production equipment is one of the most important problem that occurs while water injection and it has been recognized to be a major operational problem. the incompatibility between injected and formation waters may result in inorganic scale precipitation in the equipment and reservoir and then reduction of oil production rate and water injection rate. ...

testing plays a vital role in any language teaching program. it allows teachers and stakeholders, including program administrators, parents, admissions officers and prospective employers to be assured that the learners are progressing according to an accepted standard (douglas, 2010). the problems currently facing language testers have both practical and theoretical implications but the first i...

a semi-empirical mathematical model for predicting physical part of ignition delay period in the combustion of direct - injection diesel engines with swirl is developed . this model based on a single droplet evaporation model . the governing equations , namely , equations of droplet motion , heat and mass transfer were solved simultaneously using a rung-kutta step by step unmerical method . the...

بندپایان با داشتن بیش از یک میلیون گونه، بزرگترین شاخه جانوری محسوب می شوند. خانواده کنه های سخت در زیر راسته متااستیگماتا و راسته کنه سانان (آکارینا) از شاخه بندپایان قرار دارند (wall and shearer, 2001). تاکنون 650 گونه و در حدود 13 جنس در 5 زیرخانواده از آنها گزارش گردیده است (wall and shearer, 2001 ). به طوری که 10 درصد کنه ها از حیوانات اهلی تغذیه می کنند و در انتقال عوامل بیماری زا به انسا...