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...

Vegetation changes can change the rainfall and temperature cycle and also climate fluctuations, especially temperature and precipitation parameters, have significant effects on vegetation. Climate change causes restriction for plant activities which cause changes in vegetation indices including NPP. Considering that Qazvin plain has been affected by climate fluctuations and drought in recent ye...

today, the route for economic development in most countries is the same as international open competitive economy. economic institutes well known that supportive public economy belonged on the past and they may compete in the global economy. it is obvious that if they have no competitive potency or not familiar with competition technique, they may be devastated. banking system aims to collect t...

the present study was concerned with exploring the frequency and linguistic focus of corrective feedback types given by novice and experienced female teachers working with young learners and compared it with those of elementary classes for adults. moreover, it aimed at measuring learners’ acknowledgement of teachers’ corrective feedback in the form of uptake in relation to linguistic coverage o...

efl/esl textbooks have been regarded as essential language teaching materials with which the learners spend about 70 up to 90 percent of their class time. the important role they play and their vast use make them not only influential in learning the language but also in shaping values and attitudes. put it another way, textbooks socialize learners using their contents (i.e. texts, illustrations...

while performance-based language assessment has led to an increased authenticity and content validity in the practice of writing assessment, the reliability of ratings has become a major issue. research findings have shown different reactions by native english speaker (nes) and non-native english speaker (nns) teachers to students’ writings. the focus of this study is on investigating whether i...

this research is a study on indicators of listening instruction in iranian english as a foreign language (efl) curriculum at guidance school and high school educational levels. this thesis aims at determining: a) the indicators of listening instruction at guidance school and high school efl curriculum. b) the indicators of listening instruction in irans guidance school and high school efl curri...

saluk mount is selected for devonian biostratigraphy. this area located at southwest of bojnurd. in this study three sections are selected and two sections, chahar-borj and tabar sections with a thickness of 650 m, which consist mainly of calcareous sediments was studied in detailed but third section, qelli section, with a thickness of about 450m which consist mainly of sandstone and evaporates...