in this research we have studied the effect of some transition-metals (cu, ag and au) substitutions on two-electron reduction potential of flavins by application of dft method. all geometries have been optimized at blyp level of theory and “6-31+g** + lanl2dz” mixed basis set. the frequency job at the same method and basis sets has been performed to obtain gibbs free energy of compounds. it h...

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

burnout is a response to the chronic work stress which is prevalent mostly among the people who do people job, like teaching. the purpose of this study was to develop a valid and reliable instrument that can measure burnout in foreign language teachers. although some widely used instruments were developed before which measured burnout in teachers, a specific instrument which include specific sy...

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 ...

the present study reports an analysis of response articles in four different disciplines in the social sciences, i.e., linguistics, english for specific purposes (esp), accounting, and psychology. the study has three phases: micro analysis, macro analysis, and e-mail interview. the results of the micro analysis indicate that a three-level linguistic pattern is used by the writers in order to cr...

Mehrgerd region of Semirom county has faced the water shortage for several years. The emergence of drought has led to a decline in water resources in recent years; and there are various reasons for climate change and increased consumption in order to reduce water resources. The present study aimed to investigate the process of temperature and precipitation variations and its possible effects on...

abstract this study investigates the teachers’ correction of students’ spoken errors of linguistic forms in efl classes, aiming at (a) examining the relationship between the learners’ proficiency level and the provision of corrective feedback types, (b) exploring the extent to which teachers’ use of different corrective feedback types is related to the immediate types of context in which err...

Groundwater resources are considered as a largest reservoir of available freshwater in the world. According to the importance and scarcity of this precious resource, studying the groundwater quality changes is very important. Declines in water level of Urmia lake has led to increase in the salinity of water in this lake. In this paper, water level reduction effects were studied on qualitative c...