فهرست مطالب azhar ali

In this research, we develop and prepare some of the polymers based on polythioesters using cetrimide as an ionic liquid and phase transfer catalyst. All of the polymers were prepared through the reaction of 5,5'-methylenebis (1,3,4-oxadiazole-2-thiol) with five types of diacyl chloride derivatives in the presence of cetrimide as phase transfer catalyst in the mixture of water and chloroform at room temperature. The chemical structure of synthesized polymers was determined using 1H NMR and 13C NMR spectroscopy. The mechanical and thermal stability of the synthesized polymers were investigated. In addition, using DFT calculation, the chemical optimization of synthesized polymers was presented. Moreover, the catalytic activity of cetrimide was compared with four types of ionic liquid with phase transfer catalyst roles. Additionally, the application of synthesized polymers in bone cement was investigated.

Effect of stocking densities on the growth, survival and production of bata, Labeo bata fry and fingerlings were tested in a primary nursery rearing system. The experiment was conducted for a period of 4 weeks in six earthen nursery ponds having an area of 0.032 ha each. Four-day-old fry stocked at 1.0 million/ha was designated as treatment-1 (T1), 1.5 million/ha as treatment-2 (T2) and 2.0 million/ ha as treatment-3 (T3). At stocking, all fry were of same age with a mean length and weight of 1.03±0.03 cm and 0.12±0.01 g, respectively. Fry in all the treatments were fed with Mega commercial fish feed. Physico-chemical parameters such as water temperature, transparency, dissolve oxygen, pH and total alkalinity in all the treatments were suitable ranges for fry and fingerling rearing. Plankton population (both phytoplankton and zooplankton) were found to be at optimum level for fish culture. Highest weight gain was observed in T1 (3.46±0.08) and lowest in T3 (1.98±0.03). Final length, final weight and survival of fingerlings also followed the same trends as weight gain. Fingerlings in T1 produced significantly higher specific growth rate (12.15±0.08) than T2 (11.31±0.03) and T2 (10.22±0.05). Feed conversion ratio was significantly lower in T1 (0.26±0.01) than T2 (0.42±0.02) and T3 (0.65±0.01). Significantly higher number of fingerlings was produced in T3 (1177700±4700) than T2 (963300±9900) and T1 (717850±7350), respectively. Despite of this, consistently higher net benefits were found from T1 than T2 and T3. Overall, highest growth (3.60±0.16 g), survival (71.79 ± 1.04%) and net benefits (TK. 127,087.00) of fingerlings were obtained at a density of 1.0 million hatchlings/ha. Therefore, out of three stocking densities, 1.0 million fry/ha appears to be most suitable stocking density for nursing and rearing of L. bata fry and fingerlings in primary nursing.