flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

learning-oriented assessment seeks to emphasise that a fundamental purpose of assessment should be to promote learning. it mirrors formative assessment and assessment for learning processes. it can be defined as actions undertaken by teachers and / or students, which provide feedback for the improvement of teaching and learning. it also contrasts with equally important measurement-focused appro...

Introduction: Seismicity is closely related to active Quaternary faults.This attracts many researchers to investigate the quantitative relationships between them. As a new parameter, FMP is defined to quantify earthquake risk.Iran is one of the most active areas of the world in terms of tectonic activities in the Alps-Himalayan belt. One of the characteristics of this belt includes the presence...

in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

Earthquake and explosion are destructive dynamic forces. These forces can cause severe damage to the structure due to the time-dependent nature of the impact. One of the most important parameters for checking the stability of structures is the study of their buckling modes. The stability check has a direct relationship with the critical load of the columns. In this paper, the effects of simulta...

Radon and Thoron are the radioisotopes which radiate high alpha energy particles. These two gases can enter in the body by different ways such as inhalation, eating and drinking and then destroy body`s internal tissues and cause the lung cancer. The condensation of these gases differs in various areas and is more in zones near active faults. In this research, first the relation of Radon and Tho...

abstract the present study investigated the effects of task types and involvement load hypothesis on incidental learning of 10 target words (tws) in junior high schools (jhss) in givi, ardabil. the tasks deployed in this study were two input-based tasks (reading plus dictionary use with an involvement index of 3, and reading plus gap-fill task with an involvement index of 2), and one output-ba...