The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish ...The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish the delicate bal-ance of hydrogen bonding network between solvent and cellulose.Herein,we proposed the concept of“hydrogen bond producers”for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid([TMGH][MAA])to enhance the dissolution of cellulose.The optimization of physicochemical properties for[TMGH][MAA]solvent as a function of urea concentration revealed a remark-able increase in cellulose solubility from 13%to 17%(w/w)by adding only 0.25 wt%urea,highlighting the efficiency of[TMGH][MAA]as a power-ful solvent for the dissolution of cellulose.The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions,reducing the interference with the active ions bonded to cellulose.Furthermore,the considerable enhancement on compre-hensive properties of regenerated cellulose films demonstrated the effectiveness of[TMGH][MAA]/urea solvent.The concept of“hydrogen bond producers”presented here opens a new avenue for significantly enhancing the dissolu-tion of natural cellulose,promoting the sustainable development in large-scale processing of cellulose.展开更多
Following the reform of the governance of irrigation schemes in Niger, producer cooperatives are encountering real difficulties in ensuring effective and efficient management of irrigation water, infrastructure mainte...Following the reform of the governance of irrigation schemes in Niger, producer cooperatives are encountering real difficulties in ensuring effective and efficient management of irrigation water, infrastructure maintenance and renewal of hydromechanical equipment. The objective of this research is to analyze the issues and challenges of capacity building for Konni producers in the context of AHA management reform in Niger. The methodological approach adopted is based on documentary research and field surveys with all the actors directly concerned with the management of the Konni irrigated perimeter. A total of 448 people were interviewed in all the localities selected. Direct observation and interview are the two field data collection techniques adopted. The data collected was processed and on the basis of the established diagnosis, the training needs were identified. The results show that there are several experiences in terms of training and capacity building of actors in charge of the management of irrigation systems at the Konni AHA level. However, the sustainability of the perimeter is threatened by various crises. The main themes that founded the first training were related to the mobilization, transport and distribution of irrigation water, operation and maintenance, and setting and collection of the fee. In view of the expectations of operators, future issues and challenges, the training modules are increasingly oriented towards social management, the integration of gender in management and environmental impacts. Even if technical progress is possible, the real lever is organizational and requires the professionalization of irrigators. This process requires a new pedagogical approach aimed at irrigators.展开更多
On the basis of defining the producers in the supply chain of agricultural products,the SWOT analysis is adopted to analyze the advantages,disadvantages,opportunities and threats of producers in the supply chain of Ch...On the basis of defining the producers in the supply chain of agricultural products,the SWOT analysis is adopted to analyze the advantages,disadvantages,opportunities and threats of producers in the supply chain of Chinese agricultural products.The paper analyzes the advantages of producers in the supply chain of agricultural products from three aspects including land resources,technology level of producers and input costs.The disadvantages of producers in the supply chain of agricultural products are analyzed from three aspects including scale level,mechanization and technology level and profit level.The opportunities of producers in the supply chain of agricultural products are analyzed from the aspects of laws,policies,capitals and technologies.The threats confronted by the producers in the supply chain of agricultural products are analyzed from foreign producers,negotiation control of supply chain of agricultural chain,environment protection and quality safety standard.On the basis of the analysis,the relevant suggestions on facilitating the interests of producers in the supply chain of Chinese agricultural products are put forward,including fully displaying the advantages of land resources;improving the knowledge and technology level of supply chain of agricultural production;establishing the alliances of producers of agricultural products to expand production scale;improving the quality of agricultural products to satisfy the relevant safety quality standard and environmental protection standard.展开更多
The aim of the present study was to evaluate the impact of the technological level in small-scale dual-purpose cow-calf <em>Bos indicus</em> female operations on the resumption of the ovarian activity post...The aim of the present study was to evaluate the impact of the technological level in small-scale dual-purpose cow-calf <em>Bos indicus</em> female operations on the resumption of the ovarian activity post-partum. A total of 13 small scale dual-purpose <em>Bos indicus</em> × <em>Bos taurus</em> operations were included in this experiment and they were classified according to their technological status as: high technological status (HT), medium technological status (MT) and low technological status (LT). Ninety-three mature cows were treated with either a CIDR (controlled internal drug release device) with estradiol benzoate (CIDR+EB) or alone (CIDR). At day 9 all animals received intravaginally a CIDR for nine days. At day 0, the CIDR was withdrawn and 24 hours later one dose of estradiol benzoate was administered to 51 cows (17 in HT, 17 in MT and 17 in LT), the remaining animals (n = 42) did not receive the estradiol benzoate administration (14 in HT, 13 in MT and 15 in LT). Comparisons were performed on serum progesterone concentrations after CIDR treatment. By day 7 after implant withdrawal, the proportion of cows that resume ovarian activity detected by progesterone concentration increased in all technological level farms, no statistical main effect was observed within technological level. By day 17 there was a significant main effect of technological level (P = 0.05) on the proportion of animal that resumed the estrous cycles, but neither a main effect of treatment (P = 0.97) nor an interaction between technological level and treatment (P = 0.98). Furthermore, technological level of the farm showed a tendency (P = 0.07) to affect that resume the estrous activity, and a significant effect of treatment was observed (P = 0.005) but no interaction between technological level and treatment. The proportion of cows that showed estrus was different across technological level (P = 0.02), the highest proportion of cows showing estrus regardless of treatment was in the HT: 90% (40% CIDR and 50% CIDR+EB), MT: 50% (13.展开更多
Decentralised energy (DE), also known as distributed energy, refers to power generation and energy storage systems located at or near the point of use;and may also be connected to a local distribution network system o...Decentralised energy (DE), also known as distributed energy, refers to power generation and energy storage systems located at or near the point of use;and may also be connected to a local distribution network system or to a high voltage transmission system either directly or through a local distribution network system. It is generated or stored by a variety of small devices commonly referred to as distributed energy resources (DER);the definition also extends to include stand-alone systems completely isolated from the public networks. The contribution made by independent power producers (IPP’s) through deployment of DER in the African energy market is critical to fast-tracking the deployment of renewables, diversification of the energy mix and enhancing access to modern and clean energy. There is need to develop policy mechanisms aimed at enhancing the current positive drive in the energy market;and this has been observed to be a driving factor in countries which have developed appropriate policy strategies. This paper presents the concept of DE in detail and how it could complement efforts to addressing the current energy crises in Southern Africa;it also looks at policy developments in Africa and presents the scenarios in the two southern African countries of South Africa and Botswana. The research is based on an extensive review of literature on the subject matter, consultations with stakeholders as well as feedback from the Learning Network for Sustainable Energy Systems (LeNSes) workshops.展开更多
This study was aimed at selecting starter cultures for bio-enriching ogi (fermented cereal gruel) using folate-producing microorganisms. The folate-producing microorganisms were isolated by incorporating folate analog...This study was aimed at selecting starter cultures for bio-enriching ogi (fermented cereal gruel) using folate-producing microorganisms. The folate-producing microorganisms were isolated by incorporating folate analogue, methotrexate in the isolation medium and further screened for folate production by growth in Folic Acid Casei Medium. Folate production was quantified using 3-aminophenol spectrophotometric method. Folate-producing lactic acid bacteria from fermenting maize slurry were species of Lactobacillus, Lactococcus, Pediococcus and Leuconostoc while yeast isolates were mainly species of Candida and Saccharomyces. However, Lactobacillus plantarum X13, Pediococcus pentosaceus L73, Candida parapsilosis Y77 and Candida tropicalis Y74 were used as starter cultures singly and in combination for the fermentation and production of ogi. The highest folate concentration, 30.97 ± 0.37 μg/ml, was observed after 24 h of the co-fermentation of maize slurry with Lactobacillus plantarum X13 and Candida tropicalis Y74. This represents a triple fold of the folate concentration observed in unfermented maize slurry. The pH of the fermenting maize slurry was observed to decrease from 6.12 to 3.60, while the reducing sugars and the titratable acidities were observed to increase as fermentation progressed. Sensory evaluation of the ogi samples after fermentation showed high general acceptability comparable to the naturally fermented ogi as regards to colour, taste, flavour, aroma and texture. The data made available in this study suggest the possibility of folate enrichment of ogi and its use as a vehicle for increasing folate availability to consumers thereby preventing folate deficiency diseases prevalent in many African countries.展开更多
基金Science and Technology Department of Sichuan Province,Grant/Award Number:2022YFH0094National Natural Science Foundation of China,Grant/Award Numbers:51973141,52033005,U21A2090。
文摘The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish the delicate bal-ance of hydrogen bonding network between solvent and cellulose.Herein,we proposed the concept of“hydrogen bond producers”for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid([TMGH][MAA])to enhance the dissolution of cellulose.The optimization of physicochemical properties for[TMGH][MAA]solvent as a function of urea concentration revealed a remark-able increase in cellulose solubility from 13%to 17%(w/w)by adding only 0.25 wt%urea,highlighting the efficiency of[TMGH][MAA]as a power-ful solvent for the dissolution of cellulose.The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions,reducing the interference with the active ions bonded to cellulose.Furthermore,the considerable enhancement on compre-hensive properties of regenerated cellulose films demonstrated the effectiveness of[TMGH][MAA]/urea solvent.The concept of“hydrogen bond producers”presented here opens a new avenue for significantly enhancing the dissolu-tion of natural cellulose,promoting the sustainable development in large-scale processing of cellulose.
文摘Following the reform of the governance of irrigation schemes in Niger, producer cooperatives are encountering real difficulties in ensuring effective and efficient management of irrigation water, infrastructure maintenance and renewal of hydromechanical equipment. The objective of this research is to analyze the issues and challenges of capacity building for Konni producers in the context of AHA management reform in Niger. The methodological approach adopted is based on documentary research and field surveys with all the actors directly concerned with the management of the Konni irrigated perimeter. A total of 448 people were interviewed in all the localities selected. Direct observation and interview are the two field data collection techniques adopted. The data collected was processed and on the basis of the established diagnosis, the training needs were identified. The results show that there are several experiences in terms of training and capacity building of actors in charge of the management of irrigation systems at the Konni AHA level. However, the sustainability of the perimeter is threatened by various crises. The main themes that founded the first training were related to the mobilization, transport and distribution of irrigation water, operation and maintenance, and setting and collection of the fee. In view of the expectations of operators, future issues and challenges, the training modules are increasingly oriented towards social management, the integration of gender in management and environmental impacts. Even if technical progress is possible, the real lever is organizational and requires the professionalization of irrigators. This process requires a new pedagogical approach aimed at irrigators.
基金Supported by the Innovation Fund Project for Graduate Student of Xihua University
文摘On the basis of defining the producers in the supply chain of agricultural products,the SWOT analysis is adopted to analyze the advantages,disadvantages,opportunities and threats of producers in the supply chain of Chinese agricultural products.The paper analyzes the advantages of producers in the supply chain of agricultural products from three aspects including land resources,technology level of producers and input costs.The disadvantages of producers in the supply chain of agricultural products are analyzed from three aspects including scale level,mechanization and technology level and profit level.The opportunities of producers in the supply chain of agricultural products are analyzed from the aspects of laws,policies,capitals and technologies.The threats confronted by the producers in the supply chain of agricultural products are analyzed from foreign producers,negotiation control of supply chain of agricultural chain,environment protection and quality safety standard.On the basis of the analysis,the relevant suggestions on facilitating the interests of producers in the supply chain of Chinese agricultural products are put forward,including fully displaying the advantages of land resources;improving the knowledge and technology level of supply chain of agricultural production;establishing the alliances of producers of agricultural products to expand production scale;improving the quality of agricultural products to satisfy the relevant safety quality standard and environmental protection standard.
文摘The aim of the present study was to evaluate the impact of the technological level in small-scale dual-purpose cow-calf <em>Bos indicus</em> female operations on the resumption of the ovarian activity post-partum. A total of 13 small scale dual-purpose <em>Bos indicus</em> × <em>Bos taurus</em> operations were included in this experiment and they were classified according to their technological status as: high technological status (HT), medium technological status (MT) and low technological status (LT). Ninety-three mature cows were treated with either a CIDR (controlled internal drug release device) with estradiol benzoate (CIDR+EB) or alone (CIDR). At day 9 all animals received intravaginally a CIDR for nine days. At day 0, the CIDR was withdrawn and 24 hours later one dose of estradiol benzoate was administered to 51 cows (17 in HT, 17 in MT and 17 in LT), the remaining animals (n = 42) did not receive the estradiol benzoate administration (14 in HT, 13 in MT and 15 in LT). Comparisons were performed on serum progesterone concentrations after CIDR treatment. By day 7 after implant withdrawal, the proportion of cows that resume ovarian activity detected by progesterone concentration increased in all technological level farms, no statistical main effect was observed within technological level. By day 17 there was a significant main effect of technological level (P = 0.05) on the proportion of animal that resumed the estrous cycles, but neither a main effect of treatment (P = 0.97) nor an interaction between technological level and treatment (P = 0.98). Furthermore, technological level of the farm showed a tendency (P = 0.07) to affect that resume the estrous activity, and a significant effect of treatment was observed (P = 0.005) but no interaction between technological level and treatment. The proportion of cows that showed estrus was different across technological level (P = 0.02), the highest proportion of cows showing estrus regardless of treatment was in the HT: 90% (40% CIDR and 50% CIDR+EB), MT: 50% (13.
文摘Decentralised energy (DE), also known as distributed energy, refers to power generation and energy storage systems located at or near the point of use;and may also be connected to a local distribution network system or to a high voltage transmission system either directly or through a local distribution network system. It is generated or stored by a variety of small devices commonly referred to as distributed energy resources (DER);the definition also extends to include stand-alone systems completely isolated from the public networks. The contribution made by independent power producers (IPP’s) through deployment of DER in the African energy market is critical to fast-tracking the deployment of renewables, diversification of the energy mix and enhancing access to modern and clean energy. There is need to develop policy mechanisms aimed at enhancing the current positive drive in the energy market;and this has been observed to be a driving factor in countries which have developed appropriate policy strategies. This paper presents the concept of DE in detail and how it could complement efforts to addressing the current energy crises in Southern Africa;it also looks at policy developments in Africa and presents the scenarios in the two southern African countries of South Africa and Botswana. The research is based on an extensive review of literature on the subject matter, consultations with stakeholders as well as feedback from the Learning Network for Sustainable Energy Systems (LeNSes) workshops.
文摘This study was aimed at selecting starter cultures for bio-enriching ogi (fermented cereal gruel) using folate-producing microorganisms. The folate-producing microorganisms were isolated by incorporating folate analogue, methotrexate in the isolation medium and further screened for folate production by growth in Folic Acid Casei Medium. Folate production was quantified using 3-aminophenol spectrophotometric method. Folate-producing lactic acid bacteria from fermenting maize slurry were species of Lactobacillus, Lactococcus, Pediococcus and Leuconostoc while yeast isolates were mainly species of Candida and Saccharomyces. However, Lactobacillus plantarum X13, Pediococcus pentosaceus L73, Candida parapsilosis Y77 and Candida tropicalis Y74 were used as starter cultures singly and in combination for the fermentation and production of ogi. The highest folate concentration, 30.97 ± 0.37 μg/ml, was observed after 24 h of the co-fermentation of maize slurry with Lactobacillus plantarum X13 and Candida tropicalis Y74. This represents a triple fold of the folate concentration observed in unfermented maize slurry. The pH of the fermenting maize slurry was observed to decrease from 6.12 to 3.60, while the reducing sugars and the titratable acidities were observed to increase as fermentation progressed. Sensory evaluation of the ogi samples after fermentation showed high general acceptability comparable to the naturally fermented ogi as regards to colour, taste, flavour, aroma and texture. The data made available in this study suggest the possibility of folate enrichment of ogi and its use as a vehicle for increasing folate availability to consumers thereby preventing folate deficiency diseases prevalent in many African countries.
