Municipal solid waste generation is strongly linked to rising human population and expanding urban areas, with significant implications on urban metabolism as well as space and place values redefinition. Effective man...Municipal solid waste generation is strongly linked to rising human population and expanding urban areas, with significant implications on urban metabolism as well as space and place values redefinition. Effective management performance of municipal solid waste management underscores the interdisciplinarity strategies. Such knowledge and skills are paramount to uncover the sources of waste generation as well as means of waste storage, collection, recycling, transportation, handling/treatment, disposal, and monitoring. This study was conducted in Dar es Salaam city. Driven by the curiosity model of the solid waste minimization performance at source, study data was collected using focus group discussion techniques to ward-level local government officers, which was triangulated with literature and documentary review. The main themes of the FGD were situational factors (SFA) and local government by-laws (LGBY). In the FGD session, sub-themes of SFA tricked to understand how MSW minimization is related to the presence and effect of services such as land use planning, availability of landfills, solid waste transfer stations, material recovery facilities, incinerators, solid waste collection bins, solid waste trucks, solid waste management budget and solid waste collection agents. Similarly, FGD on LGBY was extended by sub-themes such as contents of the by-law, community awareness of the by-law, and by-law enforcement mechanisms. While data preparation applied an analytical hierarchy process, data analysis applied an ordinary least square (OLS) regression model for sub-criteria that explain SFA and LGBY;and OLS standard residues as variables into geographically weighted regression with a resolution of 241 × 241 meter in ArcMap v10.5. Results showed that situational factors and local government by-laws have a strong relationship with the rate of minimizing solid waste dumping in water bodies (local R square = 0.94).展开更多
Organic light-emitting diodes(OLEDs)have important applications in the field of next-generation displays and lighting,and phosphorescent iridium complexes are an important class of electroluminescent phosphorescent ma...Organic light-emitting diodes(OLEDs)have important applications in the field of next-generation displays and lighting,and phosphorescent iridium complexes are an important class of electroluminescent phosphorescent materials.In this paper,Ir(bmppy)_(3),tris(4-methyl-2,5-diphenylpyridine)iridium,was synthesized and elvaluted for photo-physical characteristics.Single crystals suitale for X-ray diffraction(XRD)were grown from a mixture solvent of dichloromethane and absolute ethanol.The composition and structur of Ir(bmppy)_(3)were determined by element analysis,NMR spectra and XRD.The complex crystallizes in the monoclinic symmetry with the space group P21/c with a slightly distorted octahedral configuration.As measured by UV-Visible and photoluminescence spectra,Ir(bmppy)_(3) displays a maximum emission at at 527 nm at ambient temperature,a typical green-emitting profile.The complex has potential for application in the OLED industry.展开更多
The aim of this study is to evaluate the insecticidal potential of aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae on Caryedon serratus Ol.(Coleoptera,Bruchidae),an insect pest of groundnut...The aim of this study is to evaluate the insecticidal potential of aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae on Caryedon serratus Ol.(Coleoptera,Bruchidae),an insect pest of groundnut grains in the Republic of Guinea.To do this,tests on their insecticidal efficacy were carried out separately on groups of 8 bruchids using concentrations of aqueous extracts from their leaves in jars each containing 20 g of groundnut.The mortality of the bruchids and the impact of their aqueous extracts were observed and recorded for 96 h and 120 days after infestation,followed by a test of the germinative power of the seeds.Concentrations(C1)of aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae applied to 20 g of groundnut resulted in bruchid mortality of 86.99%and 78.82%of each plant respectively.At the same doses,the treated seeds were not attacked during 4 months’storage.The germination rate of groundnut seeds at the start and end of the experiment was 97.65%and 93.60%respectively.Thus,aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae can be considered as an alternative bio-insecticide against pests in groundnut storage shops.展开更多
文摘Municipal solid waste generation is strongly linked to rising human population and expanding urban areas, with significant implications on urban metabolism as well as space and place values redefinition. Effective management performance of municipal solid waste management underscores the interdisciplinarity strategies. Such knowledge and skills are paramount to uncover the sources of waste generation as well as means of waste storage, collection, recycling, transportation, handling/treatment, disposal, and monitoring. This study was conducted in Dar es Salaam city. Driven by the curiosity model of the solid waste minimization performance at source, study data was collected using focus group discussion techniques to ward-level local government officers, which was triangulated with literature and documentary review. The main themes of the FGD were situational factors (SFA) and local government by-laws (LGBY). In the FGD session, sub-themes of SFA tricked to understand how MSW minimization is related to the presence and effect of services such as land use planning, availability of landfills, solid waste transfer stations, material recovery facilities, incinerators, solid waste collection bins, solid waste trucks, solid waste management budget and solid waste collection agents. Similarly, FGD on LGBY was extended by sub-themes such as contents of the by-law, community awareness of the by-law, and by-law enforcement mechanisms. While data preparation applied an analytical hierarchy process, data analysis applied an ordinary least square (OLS) regression model for sub-criteria that explain SFA and LGBY;and OLS standard residues as variables into geographically weighted regression with a resolution of 241 × 241 meter in ArcMap v10.5. Results showed that situational factors and local government by-laws have a strong relationship with the rate of minimizing solid waste dumping in water bodies (local R square = 0.94).
文摘Organic light-emitting diodes(OLEDs)have important applications in the field of next-generation displays and lighting,and phosphorescent iridium complexes are an important class of electroluminescent phosphorescent materials.In this paper,Ir(bmppy)_(3),tris(4-methyl-2,5-diphenylpyridine)iridium,was synthesized and elvaluted for photo-physical characteristics.Single crystals suitale for X-ray diffraction(XRD)were grown from a mixture solvent of dichloromethane and absolute ethanol.The composition and structur of Ir(bmppy)_(3)were determined by element analysis,NMR spectra and XRD.The complex crystallizes in the monoclinic symmetry with the space group P21/c with a slightly distorted octahedral configuration.As measured by UV-Visible and photoluminescence spectra,Ir(bmppy)_(3) displays a maximum emission at at 527 nm at ambient temperature,a typical green-emitting profile.The complex has potential for application in the OLED industry.
文摘The aim of this study is to evaluate the insecticidal potential of aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae on Caryedon serratus Ol.(Coleoptera,Bruchidae),an insect pest of groundnut grains in the Republic of Guinea.To do this,tests on their insecticidal efficacy were carried out separately on groups of 8 bruchids using concentrations of aqueous extracts from their leaves in jars each containing 20 g of groundnut.The mortality of the bruchids and the impact of their aqueous extracts were observed and recorded for 96 h and 120 days after infestation,followed by a test of the germinative power of the seeds.Concentrations(C1)of aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae applied to 20 g of groundnut resulted in bruchid mortality of 86.99%and 78.82%of each plant respectively.At the same doses,the treated seeds were not attacked during 4 months’storage.The germination rate of groundnut seeds at the start and end of the experiment was 97.65%and 93.60%respectively.Thus,aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae can be considered as an alternative bio-insecticide against pests in groundnut storage shops.
