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 ...

in the past couple of decades sociocultural theory of sla and its implications in efl contexts have attracted attentions of research circles worldwide and aroused some controversies. firth and wagner (1997) have questioned the principles of the cognitive view which gives importance to mental constructs in favor of sociocultural view which highlights social and contextual constructs. but if soci...

With the aim of comparing the grain yield and yield components of 16 oilseed rape (Brassica napus L.) mutant lines with cultivars Talayeh, Zarfam, Express and Okapi as check cultivar an experiment was conducted based on  randomized complete block design with three replications during 2015-2016 cropping season in experimental field of Seed and Plant Improvement Institute (SPII) in Karaj. Analysi...

any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

purpose a metabolic abnormality such as obesity is a major obstacle in the maintenance of the human health system and causes various chronic diseases including type 2 diabetes, hypertension, cardiovascular diseases, as well as various cancers. this study was designed to summarize the recent scientific knowledge regarding the anti-obesity role of curcumin (diferuloylmethane), which is isolated f...

Rice (Oryza sativa L.) is providing food of half of the world population, and in some regions salinity stress reduces yield of this plant. In order to develop planting of rice in regions with saline water or fields, chlorophyll rate, chlorophyll fluorescence indices and grain yield of some rice cultivars were evaluated in summer, 2012, at the farm of college of Agriculture, at Yasouj University...

the importance of writing as a complex skill in applied linguistics has drawn the attention of many researchers to evaluate textbooks in order to help learners gain self-sufficiency and autonomy in the field of language use and communication. investigations have shown that developments in textbooks evaluation can promote the quality of pedagogies and consequently the learning. this study attemp...

“any science seeks generalities; the aim is to transcend knowledge of particular cases by discovering general regularities or laws” (chesterman, 2001, p. 1). these were the words of chesterman whose paper has served as a typical example of numerous papers carried out on ‘translation universals’ since the mid-nineties. blum-kulka (1986) is among translation studies scholars who proposed ‘explici...

the following null hypothesis was proposed: h : there is no significant difference between the use of semantically or communicatively translates scientific texts. to test the null hypothesis, a number of procedures were taken first, two passages were selected form soyrcebooks of food and nutrition industry and gardening deciplines. each, in turn, was following by a number of comprehension quest...

abstract ion selective electrodes (ises) are electrochemical sensors that respond selectivity to the activity of ionic species. an ion-selective electrode is an electrochemical device that uses a thin selective membrane or film as the recognition element, and is an electrochemical half-cell equivalent to other half-cells of the zeroth (inert metal in a redox electrolyte). in common methods o...