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...

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 ...

date juice was treated by cross- flow ultra-filtration with molecular weight cut-off (mwco) of 5 kda. optimized levels of feed brix, tmp and operation time were determined as 47.13, 82.11 psi and 30 min, respectively. under such conditions, 80.94% decolourisation and 97.78 % turbidity reduction were obtained while loss of glucose and fructose were estimated to be only 3.49% and 9.62%, respectiv...

the main impetus for our research is provided by the growing interest worldwide in ultra thin silicon dioxide on silicon based nano devices. the obvious need for better knowledge in the ultra thin gate silicon dioxides, is motivated both by interests in fundamental research and phenomenology as well as by interests in possible applications, which can be found with better fitting of experimental...

a newly designed printed slot antenna is presented that incorporates variable two band-notched functions for ultra-wideband (uwb) applications. the two band notches of this coplanar waveguide (cpw) fed antenna are achieved by an m-shaped slot (mss) embedded in the radiating element and a c-shaped strip(css) close to ground plane, therefore two very narrow rejected properties in the wireless loc...

a variety of anthropometric and training characteristics have been identified as predictor variables for race performance in endurance and ultra-endurance athletes. anthropometric characteristics such as skin-fold thicknesses, body fat, circumferences and length of limbs, body mass, body height, and body mass index were bi-variately related to race performance in endurance athletes such as swim...