Sharif Digital Repository

Acidity values of some compound (e.g., alkanes, alcohols, carboxylic acids and amines) with or without boron substitute have been studied theoretically to evaluate the influence of boron on acidity of organic functional groups. We have derived the unoccupied reactive orbital that show the maximum localization on the boron pπ atomic orbital overlapping with the lone-pair orbital of an electron donor. Localization of unoccupied reactive orbital on the boron pπ atomic and the polarizability of the boron center are two factors which affect acidity values of functional groups. Conformational searching was performed using MM (Molecular Mechanics). The most important conformations were optimized at... 

In this thesis, two ingot of Ti-6Al-4V alloy containing titanium carbonitride particle, one with adding boron and the other without boron were fabricated by VIM furnace and using graphite crucible. Boron was added for the purpose of investigating its effect on microstructural evolution and mechanical properties. By Processing Casting ingots under TMP and heat treatment sequences, strips with 3 millimeter thickness were produced. In secondary rolling stage, rolling temperature was considered variable in alpha and alpha + beta phase field and its effect was studied on microstructural characteristics and mechanical properties. In as-rolled condition, it was found that increasing the rolling... 

Propylene is one of the key material in petrochemical industries. In recent years, as propylene demand increases, development of new methods alongside traditional ways in production of propylene seems essential. The production of propylene from methanol using zeolitic catalysts is as one of this new methods. This method in recent years has got attention. H-ZSM-5 zeolite is one of the best catalysts appropriate for this process. However, rapid deactivation is the main problem this catalyst at the present time. Therefore, more research in order to increase stability and lifetime has been performed. The uses of promoters are as one of the simplest improvement methods of H-ZSM-5 zeolite....