khuzestan province and other western provinces of the country have been mostly affected by the impacts of the imposed war of iraq against iran and due to this impact have experienced special changes. as one of these changes, we could mention the phenomenon of the migration. these areas have experienced different forms of migrations such as exterior, interior, return migration and even the accep...

let $a$ be an abelian topological group and $b$ a trivial topological $a$-module. in this paper we define the second bilinear cohomology with a trivial coefficient. we show that every abelian group can be embedded in a central extension of abelian groups with bilinear cocycle. also we show that in the category of locally compact abelian groups a central extension with a continuous section can b...

banana xanthomonas wilt is a systemic disease of banana plants. we investigated the risk of spreading xanthomonas campestris pv. musacearum (xcm) through asymptomatic mature bunches. samples of banana fingers and rachis from markets within kampala, uganda and at border points of uganda with dr congo, tanzania, rwanda and kenya were tested for the presence of xcm through recovery of the bacteriu...

in this paper, we introduce a class of rings which is a generalization of reversible rings. let r be a ring with identity. a ring r is called central reversible if for any a,b ∈ r, ab=0 implies ba belongs to the center of r. since every reversible ring is central reversible, we study sufficient conditions for central reversible rings to be reversible. we prove that some results of reversible ri...

a hydroponic experiment was carried out to compare root anatomy and hydraulic conductivity of four barley cultivars including valfajr, karoon, afzal and zarjo under salt stress conditions. the results showed that under salt stress, the minimum diameter of vessels was observed in the peripheral metaxylem of seminal roots of valfajr cultivar and in adventitious roots; karoon with 19±3 µm had maxi...

bentonite deposits of economic interest are widespread in tashtab mountains (khur), east of isfahan province, iran. several bentonite deposits have been developed in this area as a result of eocene volcanic alteration. these deposits are classified as khur bentonite horizon. xrd analyses reveal that alteration products consist of na-montmorillonite, kaolinite, quartz, calcite, and crystobalite....