126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...

a simple, sensitive and selective method for solvent extraction and spectrophotemetric determination of lanthanum (ii) europium (iii), and cerium (iii) is described , the rare earth metals are extracted into chloroform solution of n-phenylbenzohydroxamic acid (pbha) at ph 9-10 various parameters are studied to optimize the extraction conditions. the molar absorptivity is found to increase from ...

a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...

چکیده رقابت پذیری معیاری کلیدی برای ارزیابی درجه موفقیت کشورها،صنایع و بنگاهها در میدان های رقابتی سیاسی،اقتصادی و نجاری به حساب می آید.بدین معنی که هر کشور،صنعت یا بنگاهی که از توان رقابتی بالایی در بازارهای رقابتی برخوردار باشد،می توان گفت که از رقابت پذیری بالاتری برخوردار می باشد.در تحقیقات مختلف، رقابت پذیری در سه سطح ملی،صنعت و بنگاه مورد توجه قرار گرفته که در این میان سطح بنگاه از د...

rested on sociocultural theory (sct), this study attempted to examine the effect of written corrective feedback (wcf) followed by producing written languaging on developing writing accuracy over new tasks. to this aim, two intact iranian efl classes at the low-intermediate level were randomly assigned to two experimental groups: direct (n = 25) and indirect (n = 25). both groups wrote on a numb...

abstract the present study deals with a comparison between reactive and pre-emptive focus-on-form in terms of application and efficiency. it was conducted in an intermediate english class in shahroud. 15 male learners participated in this research and their age ranged from 18 to 25. a course book, new interchange 3, and a complementary book were used. every session the learners gave lectures o...

the purpose of this two-phase, sequential mixed methods study was to find out whether there were any decencies between male and female ma students’ theses regarding the common features of academic writing such as syntactic complexity, means of integrating cited information, and organizing arguments. i chose 10 male written theses and 15 female written theses in tefl and linguistics. in the firs...

according to research, academic self-concept and academic achievement are mutually interdependent. in the present study, the aim was to determine the relationship between the academic self-concept and the academic achievement of students in english as a foreign language and general subjects. the participants were 320 students studying in 4th grade of high school in three cities of noor, nowshah...

data envelopment analysis (dea) is a powerful tool for measuring relative efficiency of organizational units referred to as decision making units (dmus). in most cases dmus have network structures with internal linking activities. traditional dea models, however, consider dmus as black boxes with no regard to their linking activities and therefore do not provide decision makers with the reasons...