Optimization of Graphene concentration in optoelectronic properties has been studied which leads to progressive stability based on Graphene-CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub&g...Optimization of Graphene concentration in optoelectronic properties has been studied which leads to progressive stability based on Graphene-CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> employing nanoparticles perovskites solar cells in this work. CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> wafer-based hetero-junction solar cells were developed under atmospheric conditions using Graphite as a hole transport layer (HTL) and TiO<sub>2</sub> as an electron transport layer (ETL). In particular a considerable enhancement in power conversion efficiency (PCE < 0.01%) has been realized using optimum Graphene concentration (0.05 g/ml). The charge injection rate is radically faster for the particular Graphene composition than the pristine perovskites, which exposes ephemeral absorption in near to UV range. Graphene incorporation increased the average crystallite size and reduced the band gap 1.32 eV in the visible range. The expensive metals such as Ag and Au have been replaced by simple ITO, which tremendously reduces the fabrication cost of the PSCs. The fabricated devices were exposed to high conservation stability without cell encapsulation ambient condition for 150 days to show excellent stability.展开更多
Effects of inoculation of Rhizobium suspension on nodulation and plant growth were examined withAlbizzia procera, Albizzia lebbeck and Leucaena leucocephala seedlings grown on sterilized and non-sterilizedsoil media. ...Effects of inoculation of Rhizobium suspension on nodulation and plant growth were examined withAlbizzia procera, Albizzia lebbeck and Leucaena leucocephala seedlings grown on sterilized and non-sterilizedsoil media. Inoculation resulted in nodule number increases of 28.6, 29.02 and 23.9 times in sterilized soiland 3.4, 3.6 and 3.27 times in non-sterilized soil for A. parocera A. lebbeck and L. leucocephala seedlingsrespectively. Total dry mass increased by 127.6%, 66.7% and 60.7% in sterilized soil and 100%, 95.5%and 52.65% in non-sterilized soil for these three legume trees, respectively, after a period of two months.Significalltly high inoculation responses of root length, root diameter, collar diameter, shoot length, and drymass of root, shoot, leaves and nodules were also observed in both sterilized and non-sterilized soil media ascompared to respective control treatments. The response to inoculation was strong in sterilized and modestin non-sterilized soils. The significantly higher response to Rhizobium inoculation over control in all thespecies tested suggested that application of Rhizobium greatly enhanced plant growth, nodulation, biomassproduction and nitrogen-fixing activity of the nodules.展开更多
This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information...This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information collected from a total of 60 households ranging from marginal, small, medium and large categories. Number of plant species increased with the increase of homestead area. A total of 33 plant species were recorded from the homegarden, of which 19 were fruit and 14 were timber tree species. Considerable number of vegetables was also planted under the shade of the homestead trees. The investment analysis showed that average benefit-cost ratios were greater than one, net present values were positive and internal rate of returns were more than 10%. Long term investment on horticulture and timber tree species is highly profitable if species like Artocarpus heterophyllus, Cocos nucifera, Tectona grandis and Swietenia macrophylla are planted.展开更多
A study was conducted to evaluate the effects of sludge （industrial and residential） on seed germination and growth performance of Acacia auriculiformis seedlings at the nursery of Institute of Forestry and Environm...A study was conducted to evaluate the effects of sludge （industrial and residential） on seed germination and growth performance of Acacia auriculiformis seedlings at the nursery of Institute of Forestry and Environmental Sciences, Chittagong University （IFESCU）, Bangladesh. Before sowing of the seeds, different combinations of sludge were incorporated with the nutrient-deficient natural forest soils. Seed germination and growth parameters of the seedlings （shoot and root length, collar diameter, fresh and dry weight of shoot, and root and total dry biomass） were recorded after one, two and three months of seed sowing. Physio-chemical parameters （pH, organic carbon, nitrogen, phosphorus, and potassium） and heavy metals （chromium, nickel, manganese, cadmium and zinc） of each treatment were also analyzed before sowing of seeds and after harvesting of seedlings. Results show that the seed germination percentage and the seedling growth parameters varied significantly in the soil added with sludge in comparison to control. The highest germination percentage （90%） was observed in the treatment of soil with residential sludge of 2：1 compared to control. The highest growth and biomass of the seedlings as well as the maximum percentage of organic carbon and nutrients （N, P and K） were also recorded in the same combination. Soil added with industrial sludge had a higher concentration of heavy metal than that of residential sludge. The highest concentrations of heavy metals were found in soil added with industrial sludge of 1：1. It is recommended that soil added with residential sludge of 2：1 provide good condition for better seed germination and growth ofA. auriculiformis seedlings in degraded forest soil.展开更多
文摘Optimization of Graphene concentration in optoelectronic properties has been studied which leads to progressive stability based on Graphene-CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> employing nanoparticles perovskites solar cells in this work. CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> wafer-based hetero-junction solar cells were developed under atmospheric conditions using Graphite as a hole transport layer (HTL) and TiO<sub>2</sub> as an electron transport layer (ETL). In particular a considerable enhancement in power conversion efficiency (PCE < 0.01%) has been realized using optimum Graphene concentration (0.05 g/ml). The charge injection rate is radically faster for the particular Graphene composition than the pristine perovskites, which exposes ephemeral absorption in near to UV range. Graphene incorporation increased the average crystallite size and reduced the band gap 1.32 eV in the visible range. The expensive metals such as Ag and Au have been replaced by simple ITO, which tremendously reduces the fabrication cost of the PSCs. The fabricated devices were exposed to high conservation stability without cell encapsulation ambient condition for 150 days to show excellent stability.
文摘Effects of inoculation of Rhizobium suspension on nodulation and plant growth were examined withAlbizzia procera, Albizzia lebbeck and Leucaena leucocephala seedlings grown on sterilized and non-sterilizedsoil media. Inoculation resulted in nodule number increases of 28.6, 29.02 and 23.9 times in sterilized soiland 3.4, 3.6 and 3.27 times in non-sterilized soil for A. parocera A. lebbeck and L. leucocephala seedlingsrespectively. Total dry mass increased by 127.6%, 66.7% and 60.7% in sterilized soil and 100%, 95.5%and 52.65% in non-sterilized soil for these three legume trees, respectively, after a period of two months.Significalltly high inoculation responses of root length, root diameter, collar diameter, shoot length, and drymass of root, shoot, leaves and nodules were also observed in both sterilized and non-sterilized soil media ascompared to respective control treatments. The response to inoculation was strong in sterilized and modestin non-sterilized soils. The significantly higher response to Rhizobium inoculation over control in all thespecies tested suggested that application of Rhizobium greatly enhanced plant growth, nodulation, biomassproduction and nitrogen-fixing activity of the nodules.
文摘This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information collected from a total of 60 households ranging from marginal, small, medium and large categories. Number of plant species increased with the increase of homestead area. A total of 33 plant species were recorded from the homegarden, of which 19 were fruit and 14 were timber tree species. Considerable number of vegetables was also planted under the shade of the homestead trees. The investment analysis showed that average benefit-cost ratios were greater than one, net present values were positive and internal rate of returns were more than 10%. Long term investment on horticulture and timber tree species is highly profitable if species like Artocarpus heterophyllus, Cocos nucifera, Tectona grandis and Swietenia macrophylla are planted.
文摘A study was conducted to evaluate the effects of sludge （industrial and residential） on seed germination and growth performance of Acacia auriculiformis seedlings at the nursery of Institute of Forestry and Environmental Sciences, Chittagong University （IFESCU）, Bangladesh. Before sowing of the seeds, different combinations of sludge were incorporated with the nutrient-deficient natural forest soils. Seed germination and growth parameters of the seedlings （shoot and root length, collar diameter, fresh and dry weight of shoot, and root and total dry biomass） were recorded after one, two and three months of seed sowing. Physio-chemical parameters （pH, organic carbon, nitrogen, phosphorus, and potassium） and heavy metals （chromium, nickel, manganese, cadmium and zinc） of each treatment were also analyzed before sowing of seeds and after harvesting of seedlings. Results show that the seed germination percentage and the seedling growth parameters varied significantly in the soil added with sludge in comparison to control. The highest germination percentage （90%） was observed in the treatment of soil with residential sludge of 2：1 compared to control. The highest growth and biomass of the seedlings as well as the maximum percentage of organic carbon and nutrients （N, P and K） were also recorded in the same combination. Soil added with industrial sludge had a higher concentration of heavy metal than that of residential sludge. The highest concentrations of heavy metals were found in soil added with industrial sludge of 1：1. It is recommended that soil added with residential sludge of 2：1 provide good condition for better seed germination and growth ofA. auriculiformis seedlings in degraded forest soil.
