18 research outputs found
Toxic effects of dimecron to fingerlings of Labeo rohita (Ham.) during acute and chronic exposures
The toxic effects of dimecron on growth, body composition and oxygen consumption of fingerlings of Labeo rohita were studied. Dimecron concentrations of 4 and 8 mg/l were used. Both acute (3-h) and chronic (15- 42 d) exposure schedules were followed. Compared with the control fish, both 4 and 8 mg/l dimecron treatment significantly suppressed weight gained in fish by 9.71% and 30% respectively during a 42 day exposure period. However, the length of fish was suppressed by 11.46% significantly only in fish group exposed to 8 mg/l dimecron. Similarly, the protein content was also significantly reduced in the above group of fish. The oxygen consumption of fish was elevated considerably, but not significantly in both group of treated fish (8.5% and 26.07%) during acute exposure. However, after 15 days of exposure the rate decreased by 18.98% significantly only in fish exposed to 8 mg/l dimecron. The threshold level of DO at low oxygen environment found to be slightly higher in fish at 8 mg/l dimecron. The survival time at the above oxygen condition was reduced during acute exposure (3-h) and that was extended during chronic (15-d) exposure
Toxic effects of dimecron to Labeo rohita Ham. fingerlings during acute and chronic exposures: histopathological changes
The exposure to the highest dimecron cone. (8 mg/1) resulted in severe histopathological
changes in different tissues of Labeo rohita fingerling. Cell necrosis, cytoplasmic
vacuolation and pycnotic nuclei were major abnormalities observed in liver tissue. The
degeneration of glomeruli and proximal tubules, cytoplasmic vacuolation and focal
haemorrhagic area were noted in case of kidney tissues. Major changes observed in
intestinal tissues were degeneration of villi, disintegrity of mucosal layers, necrosis of
epithelial cells etc. However, hypertrophy of cells and granulation of cytoplasm were
major histopathological changes observed in fish at lower dimecron cones. (4 mg/1)
Effective synthesis of biodiesel from Jatropha curcas oil using betaine assisted nanoparticle heterogeneous catalyst from eggshell of Gallus domesticus
The recovery of waste as feedstock away from organizational limitations corresponds to a prospective supplementary revenue stream for the organization. A novel waste eggshell of Gallus domesticus derived superbasic nanocatalyst was synthesized through betaine amphoteric surfactant-assisted decomposition, adsorption and precipitation processes. By varied the duration synthesis of gel mixture, the morphology transformation from liquid-solid interconnected macro-size particles to regular spheroidal nanoassemblies particles is detected. The surfactant at the liquid-solid interface facilitates the mono dispersion of nanoparticles by hindering growth of crystals. The average particle diameter of the produced superbasic nanocatalyst was in the range of 27e16 nm. The synthesized nanoparticle formation mechanism in the presence surfactant has also been addressed in this study. The catalytic activity of superbasic nanocatalyst was investigated for biodiesel production from crude Jatropha curcas oil (JCO) via glycerolysis and transesterification with methanol at atmospheric pressure. Artificial neural network (ANN) based on the genetic algorithm (GA) was applied for optimization of varied reaction parameters. It was observed that the reduction of acidity varied with varying reaction conditions. The highest fatty acid methyl ester (FAME) yield (97%) was obtained when the reaction was allowed to run at 60 C for 300 min, while at 90 C the maximal FAME yield of 98% was achieved after 120 min. The kinetic parameters of nanocatalyst were determined, and the reaction system followed pseudo first order kinetics. The results suggest that this two steps process using superbasic nanocatalyst affords a promising method to convert oils with high FFA level to biodiesel
Economic analysis of floodplain aquaculture at Daudkandi upazilla in Comilla
An economic anylysis was made to determine the cost of fish production in the floodplains at Daudkandi Upazilla in
Comilla district during the period form January to April, 2007. Survey method was followed to collect data from 20
floodplain aquaculture projects. The projects record books and personal interviews of the NGOs and Fisheries
officers were the main instruments of data collection. Statistical tools such as: range, mean, standard deviation and
percentage were employed for analysis of data. The Cobb-Douglas production function model was used to estimate
the values of co-efficients and related statistics of production function of fish culture in floodplains. Out of eleven
explanatory variables, seven co-efficients had positive sign while only four co-efficients showed negative sign. The
co-efficients bearing positive sign i.e., embankment construction, nursery and land lease, fertilizer and lime,
fingerlings, feed, labor and staff wages and miscellaneous cost made positive impact on the farm income, while the
co-efficients having negative sign i.e., area of floodplain, Office management, compensation and harvesting and
marketing cost decreased the farm income. Summation of the production co-efficients i.e., return to scale (Σbi) was
found 1.023 which implies that per one taka investment in floodplain fish culture will give rise to a profit of Tk. 1.02.
The value of R2 was found 0.892, which means that the variations in farm income could be explained to the extent of
89.2% by the included variables. The remaining 10.8% variations could not be accounted for by the multiple
regression analysis. Average fish production in the selected floodplains was 2920.43 kg/ha of which production of
cultured fish and indigenous fish was 2697.35 and 223.08 kg/ha respectively. The cost of fish production, total return
and net income were estimated Tk. 1,153,08.55, 1,76,385.49 and 61,076.94 /ha. respectively. Benefit cost ratio was
found 1.53
On the Roles of Interatomic Interactions and Coordination Numbers on Einstein Temperatures of 3D Transition Metals
We have investigated the roles of the coordination numbers and interatomic interactions on Einstien temperatures 0e for a number of bee 3d transition metals. We have employed a few of the popular transition metal pseudopotentials in the Calculations aiming at a comparative survey of the roles of these pseudopotentials on the Einstein temperature; the role of the neighboring atoms on the latter emerges as a by-product of the calculations