The effect of heat treatment for rice husk was investigated on the removal of arsenite in ground water by the adsorption onto the rice husk surface. The heat treatment was performed at the temperature from 80<sup&g...The effect of heat treatment for rice husk was investigated on the removal of arsenite in ground water by the adsorption onto the rice husk surface. The heat treatment was performed at the temperature from 80<sup>o</sup>C to 300<sup>o</sup>C in the closed system under anoxic environment. The continuous adsorption column method was applied for the removal of arsenite. The removal efficiency (75%) with rice husk treated at 150<sup>o</sup>C was better compared to those (54%) obtained with untreated rice husk. Therefore, the heat treatment of rice husk at relatively low temperature was effective for the enhancement of arsenic removal from water. The treatment conditions of As removal from aqueous solution were optimized. The developed treatment technique was applied into the real ground water sample in Bangladesh. The As concentration in sample water after treatment was approximately 18 and 8 μg/L, which was below the WHO guideline value of maximum admissible level of arsenic in ground water for Bangladesh (50 μg/L). The developed technique might become a potential avenue for simple and low cost arsenic removal methods.展开更多
This study was carried out to prepare ZnO nanoparticles incorporated acrylamide grafted chitosan composite film for possible biomedical application especially drug loading in wound healing. ZnO nanoparticles were prep...This study was carried out to prepare ZnO nanoparticles incorporated acrylamide grafted chitosan composite film for possible biomedical application especially drug loading in wound healing. ZnO nanoparticles were prepared by co-precipitation method from zinc acetate di-hydrate and incorporated in acrylamide grafted chitosan. FT-IR and TGA of the prepared composite film confirmed the successful incorporation of ZnO nanoparticles in the acrylamide-grafted polymer matrix. SEM images showed that the ZnO nanoparticles were homogeneously distributed on the porous matrix of the composite film. Water uptake and buffer uptake analysis revealed that the composite film could hold water and buffer sufficiently, which facilitated the absorption of exudate from the wound site. Amoxicillin was loaded in the prepared composite film and the maximum loading efficiency was found to be 67.33% with drug concentration of 300 ppm. In vitro studies showed greater antimicrobial activity of drug-loaded composite film compared to both pure film and standard antibiotic disc. Finally, the In vivo mouse model showed maximum healing efficiency compared to conventional gauge bandages because the loading of antibiotic in the film produced a synergistic effect and healing time was reduced.展开更多
A study has been arranged to investigate the flow of non-Newtonian fluid in a vertical asymmetrical channel using peristalsis. The porous medium allows the electrically conductive fluid to flow in the channel, while a...A study has been arranged to investigate the flow of non-Newtonian fluid in a vertical asymmetrical channel using peristalsis. The porous medium allows the electrically conductive fluid to flow in the channel, while a uniform magnetic field is applied perpendicular to the flow direction. The analysis takes into account the combined influence of heat and mass transfer, including the effects of Soret and Dufour. The flow’s non-Newtonian behavior is characterized using a Casson rheological model. The fluid flow equations are examined within a wave frame of reference that has a wave velocity. The analytic solution is examined using long wavelengths and a small Reynolds number assumption. The stream function, temperature, concentration and heat transfer coefficient expressions are derived. The bvp4c function from MATLAB has been used to numerically solve the transformed equations. The flow characteristics have been analyzed using graphs to demonstrate the impacts of different parameters.展开更多
文摘The effect of heat treatment for rice husk was investigated on the removal of arsenite in ground water by the adsorption onto the rice husk surface. The heat treatment was performed at the temperature from 80<sup>o</sup>C to 300<sup>o</sup>C in the closed system under anoxic environment. The continuous adsorption column method was applied for the removal of arsenite. The removal efficiency (75%) with rice husk treated at 150<sup>o</sup>C was better compared to those (54%) obtained with untreated rice husk. Therefore, the heat treatment of rice husk at relatively low temperature was effective for the enhancement of arsenic removal from water. The treatment conditions of As removal from aqueous solution were optimized. The developed treatment technique was applied into the real ground water sample in Bangladesh. The As concentration in sample water after treatment was approximately 18 and 8 μg/L, which was below the WHO guideline value of maximum admissible level of arsenic in ground water for Bangladesh (50 μg/L). The developed technique might become a potential avenue for simple and low cost arsenic removal methods.
文摘This study was carried out to prepare ZnO nanoparticles incorporated acrylamide grafted chitosan composite film for possible biomedical application especially drug loading in wound healing. ZnO nanoparticles were prepared by co-precipitation method from zinc acetate di-hydrate and incorporated in acrylamide grafted chitosan. FT-IR and TGA of the prepared composite film confirmed the successful incorporation of ZnO nanoparticles in the acrylamide-grafted polymer matrix. SEM images showed that the ZnO nanoparticles were homogeneously distributed on the porous matrix of the composite film. Water uptake and buffer uptake analysis revealed that the composite film could hold water and buffer sufficiently, which facilitated the absorption of exudate from the wound site. Amoxicillin was loaded in the prepared composite film and the maximum loading efficiency was found to be 67.33% with drug concentration of 300 ppm. In vitro studies showed greater antimicrobial activity of drug-loaded composite film compared to both pure film and standard antibiotic disc. Finally, the In vivo mouse model showed maximum healing efficiency compared to conventional gauge bandages because the loading of antibiotic in the film produced a synergistic effect and healing time was reduced.
文摘A study has been arranged to investigate the flow of non-Newtonian fluid in a vertical asymmetrical channel using peristalsis. The porous medium allows the electrically conductive fluid to flow in the channel, while a uniform magnetic field is applied perpendicular to the flow direction. The analysis takes into account the combined influence of heat and mass transfer, including the effects of Soret and Dufour. The flow’s non-Newtonian behavior is characterized using a Casson rheological model. The fluid flow equations are examined within a wave frame of reference that has a wave velocity. The analytic solution is examined using long wavelengths and a small Reynolds number assumption. The stream function, temperature, concentration and heat transfer coefficient expressions are derived. The bvp4c function from MATLAB has been used to numerically solve the transformed equations. The flow characteristics have been analyzed using graphs to demonstrate the impacts of different parameters.