in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

  Background and aim : A glance at different occupations and production processes showed that one of the important and popular occupational health problems in the workplace is improper climate conditions such as hot environments In this condition the core body temperature may increases and cause related diseases,, occupational accidents and reduce the efficiency . The purpose of this study was ...

acknowledgements i wish to express my gratitude to all those who have helped me in preparing this thesis. i would like to express my deep gratitude to my respected advisor dr. kourosh akef, whose advice and comments helped me in the early stages of the research and throughout the writing process. i would also like to express my gratitude to dr. hajar khanmohammad whose invaluable guidance he...

among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...

  Background & Objectives : Exposure to heat is a significant problem in the Industries. The present study aimed at the evaluation of thermal risk, measurement of heat stress index, and proposing a plan for heat control in cutting and welding units in profile factory .   Methods : The data of study was analyzed through the measurement of physical parameters with digital WBGT device...

a novel and ultra low cost isfet electrode and measurement system was designed for isfet application and detection of hydronium, hydrazinium and potassium ions. also, a measuring setup containing appropriate circuits, suitable analyzer (advantech board), de noise reduction elements, cooling system and pc was used for controlling the isfet electrode and various characteristic measurements. the t...

‘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...