فهرست مطالب dariush abdollahi

Nowadays in different industries, researchers perform many attempts to reduce manpower because it is time consuming and needs high cost, high skill, and involves more human error. For this reason, for eliminating of the manual finishing, this article investigates finishing of special curvature based forging die manufactured by EDM process, the finishing process is performed by abrasive flow machining. These dies usually are finished manually. Abrasive flow machining is used for polishing of points of workpiece, which are in the direction of abrasive flow. This is the reason that, for flow distribution in die curvature an intermediate piece is used in other to provide a passage. Two phase simulation(fluid/solid) of flow in two dimensions shows that the total pressure at each point in complete cycle (piston stroke) is equal to a constant value since a direct relation exists between the amount of material removal in the process and the pressure amount, a uniform polishing could be expected. Performed experiments assert correctness of simulation. Empirical tests showed that the abrasive grain size is larger, the material removal rate is also higher. Also, by increasing the number of courses and concentrations of abrasive, material removal rate is also increasing. Dimensional accuracy has been maintained in this process.

A 33-day feeding experiment was conducted to assess the effects of supplemented diets with sturgeon intestinal bacteria as probiotics in feeding of silver carp (Hypophthalmichthys molitrix) larvaewith average weight 200 ± 10 mg. These probiotics were isolated from gut of ten healthy fingerlings of Beluga (Huso huso) with average weight of (5.51 ± 0.31 g). Four diets (S1¡ S2¡ S3 and S4) were prepared containing similar ingredient composition and were supplemented with blend of three probiotics (Bacillus licheniformis¡ Bacillus subtilis and yeast of Saccharomyces cerevisiae) at four different levels (0¡ 1.5×106¡ 3×106¡ 4.5×106 cells per 100 g of diet¡ respectively). At the end of experiment¡ the Silver carp larvae fed probiotic supplemented diet had an improved and growth feeding performance compared to fish larvae not fed probiotics. Rearing of silver carp with feeding by experimental diets of¡ S2 and S3 (3×106 and 4.5×106 cells 100 g) resulted in better growth and feeding parameters in compared with the control. These probiotics resulted in a significant increase (P

The effect of an imported and an indigenous probiotics on growth, feeding parameters and survival of whiteleg shrimp (Litopenaeus vannamei) postlarvae (50±6.54 mg) was investigated during 60 days feeding trial. The shrimp was fed three times daily at 7 percent of biomass with three feeds supplemented with probiotics (an imported and an indigenous ones, and an equal amount of both (, plus a blank feed as control. Probiotic supplemented feed brought about a higher final weight and final length, specific growth rate, better feed conversion ratio and a higher resistance to stress (p