for a given riemannian manifold (m,g),it is an interesting question to study the existence of a conformal diffemorphism (also called as a conformal transformation) f : m ! m such that the metric g? = fg has one of the following properties: (i)(m; g?) has constant scalar curvature. (ii)(m; g?) is an einstein manifold.

abstract i the purpose of this study was to launch a thorough investigation concerning the possibility of differing orientations to the writing proficiency construct by native and non-native english speaking teacher raters. it mainly revolved around the international english language testing system (ielts) that is widely administered and employed as a measure of general proficiency in englis...

‘romanticism’ and ‘romantic’ are among the most controversial terms in literature. most readers, when encountering these words, would think of the well-known period of romanticism of the first three decades of the nineteenth century and the great six english poets known as ‘the big six’ of this period. however, romanticism does not belong to certain artists in a special period; one may seek ele...

the present study sought to investigate the role of dynamic assessment (da) in improvement of iranian efl writing performance at different language proficiency levels. to this end, after conducting the quick placement test, 60 iranian efl learners were assigned to two groups with different language proficiency levels. in both groups each participant wrote two compositions, one before and one af...

fluorescence chemical sensors for the highly sensitive and selective determination of pb2+ , hg2+, co2+ and fe3+ ions in aqueous solutions are described. the ion sensing system was prepared by incorporating lipophilic ligand (l) as a neutral ion-selective fluoroionophore in the plasticized pvc membrane containing sodium tetraphenylborate or potasium tetrakis (p-chlorophenyl) borate as a liphoph...

abstract nowadaysphotovoltaic solar cells (pvs) areacknowledged the fastest growing energy technology in the word, however, they only account for only fraction of current global renewable energy capacity. it isrecognized that this incomplete market penetration has been largely a result of the technology’sexcessive cost. so researchers are trying to find innovative, economic way with theaim of ...

دسته ای از ترکیبات شیمیائی که مخصوصا با گسترش زندگانی جدید (ماشینی)اهمیت فرآینده ای پیدامی کنند، افزودنیهای مختلف غذائی میباشند که در صنایع مربوطه بکار گرفته می شوند بکارگیری بخشی از این موا تحت عنوان طعم دهنده ها بمنظور تامین طعم و مزه طبیعی درفرآورده های صنعتی تقریبا اجتناب ناپذیر گشته و همگام با توسعه تولیدات روبه توسعه می رود. یک شناخت سیستماتیک و جامع از خواص و آثار اینگونه مواد طبیعتا مست...

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 ...

abstract the aim of the present study is to explore the impact of the cognitive reading strategy instruction on learners reading self-efficacy and their reading achievement. in order to fulfill this purpose, from 120 participants, 90 intermediate efl learners as an experimental group were chosen from three different educational settings namely, yazd university, yazd science and art un...

in this study reference as one of the five cohesive devices in the achievement of textuality in english and persian narrative/descripitive written texts is focused on and analysed . to do so , the theoretical framework elaborated by halliday and hasan (1976) and its version adapted by the writer to match the sub-types of reference in farsi are applied to the analysis of reference in english and...