in this paper, we define the notions of ultra and involution ideals in $bck$-algebras. then we get the relation among them and other ideals as (positive) implicative, associative, commutative and prime ideals. specially, we show that in a bounded implicative $bck$-algebra, any involution ideal is a positive implicative ideal and in a bounded positive implicative lower $bck$-semilattice, the not...

background: men are unavoidably exposed to ambient electromagnetic fields (emf) generated from various electrical gadgets and from power transmission lines. prostate gland plays an important role in secretion of semen as largest accessory gland of male reproductive system. it seems that protection of this gland against emf is important in spermatogenesis process. objective: the goal of this stu...

development and optimisation of fast, efficient, quantitative, economic and environmentally friendly analytical extraction techniques for the extraction clean up, and pre-concentration in the quantification of 16 usepa priority polycyclic aromatic hydrocarbons (pahs) in contaminated soils have been carried out. three different extraction methods (soxhlet, ultra sonication and mechanical shaking...

in this study, ultrafine grained 2024 al alloy based b4c particles reinforced composite was produced by mechanical milling and hot extrusion. mechanical milling was used to synthesize the nanostructured al2024 in attrition mill under argon atmosphere up to 50h. a similar process was used to produce al2024-5%wt. b4c composite powder. to produce trimodal composites, milled powders were combined w...

a nano/ultra-fine grain al-0.2wt% zr alloy was produced by accumulated roll bonding (arb) processafter 10 cycles. the fraction of high angle grain boundaries increased from 8% to 65.4% during 10passes during arb process. this alloy was subjected to tensile test at different temperatures (523,573and 623 k) and strain rates (0.1 and 0.01 s-1). the optimum condition of temperature and strain rate ...