Methane generation in landfills and its inadequate management represent the major avoidable source of anthropogenic methane today. This paper models methane production and the potential resources expected (electrical ...Methane generation in landfills and its inadequate management represent the major avoidable source of anthropogenic methane today. This paper models methane production and the potential resources expected (electrical energy production and potential carbon credits from avoided CH4 emissions) from its proper management in a municipal solid waste landfill located in Ouagadougou, Burkina Faso. The modeling was carried out using two first-order decay (FOD) models (LandGEM V3.02 and SWANA) using parameters evaluated on the basis of the characteristics of the waste admitted to the landfill and weather data for the site. At the same time, production data have been collected since 2016 in order to compare them with the model results. The results obtained from these models were compared to experimental one. For the simulation of methane production, the SWANA model showed better consistency with experimental data, with a coefficient of determination (R²) of 0.59 compared with the LandGEM model, which obtained a coefficient of 0.006. Thus, despite the low correlation values linked to the poor consistency of experimental data, the SWANA model models methane production much better than the LandGEM model. Thus, despite the low correlation values linked to the poor consistency of the experimental data, the SWANA model models methane production much better than the LandGEM V3.02 model. It was noted that the poor consistency of the experimental data justifies these low coefficients, and that they can be improved in the future thanks to ongoing in situ measurements. According to the SWANA model prediction, in 27 years of operation a biogas plant with 33% electrical efficiency using biogas from the Polesgo landfill would avoid 1,340 GgCO2e. Also, the evaluation of revenues due to electricity and carbon credit gave a total revenue derived from methane production of US$27.38 million at a cost of US$10.5/tonne CO2e.展开更多
Introduction: Worldwide, 2.3 million children died in the first 20 days after birth in 2022, according to the WHO. In Mali, according to the sixth Demographic and Health Survey, the neonatal mortality rate was estimat...Introduction: Worldwide, 2.3 million children died in the first 20 days after birth in 2022, according to the WHO. In Mali, according to the sixth Demographic and Health Survey, the neonatal mortality rate was estimated at 33% live births in 2018. The Timbuktu region had the highest neonatal mortality rate in the country with 44%. The objective of this work was to study the causes of neonatal morbidity and mortality and related factors in the paediatrics department of Timbuktu hospital. Materials and method: This was a descriptive, cross-sectional study conducted from 1 January to 31 December 2023 in the neonatology unit of the paediatrics department of Timbuktu hospital, including all newborns admitted to hospital. Results: Our study took place over 12 months, during which 618 admissions were made to the paediatric ward, including 244 newborns, i.e. 39.48%. The majority of newborns (86.5%) were admitted in the first week of life. The mean age was 3 days, with a sex ratio of 1.1 for males. Weight under 2500 g was 54.1% for an average weight of 2372 g. The main mode of admission was transfer from the hospital maternity unit (62%). The main reasons for admission were acute foetal distress (27.9%) and prematurity (26.2%). The average age of the mothers was 24, with extremes of 15 and 49. The mothers were housewives (87.3%), uneducated and primiparous (59% and 36.5% respectively);only 40.2% had made more than 3 antenatal care visits. Newborns born by vaginal delivery accounted for 80.7% and those born by caesarean section for 19.3%. The risk of infection was present in 52.5% of cases. The three leading causes of hospitalisation were birth asphyxia (40.2%), neonatal infection (32.4%) and prematurity (25%). The mortality rate was 21.7%. The main causes of death were prematurity (39.6%), birth asphyxia (32.1%) and neonatal infection (24.5%). Conclusion: Neonatal morbidity and mortality remain a concern in Timbuktu. Despite the unfavourable security situation, morbidity and mortality indicators are close to those in some hospitals in Mali. The correct application of Essential Newborn Care and antenatal care remains a major challenge for the hospital and the Timbuktu region.展开更多
The accelerated depletion of oil reserves and the often exorbitant cost of fossil fuels contribute to the development of fuels from renewable sources. The objective of this work is to analyze the influence of the prop...The accelerated depletion of oil reserves and the often exorbitant cost of fossil fuels contribute to the development of fuels from renewable sources. The objective of this work is to analyze the influence of the properties of renewable fuels on their evaporation in natural convection, their combustion and their use in internal combustion engines. A summary of the various numerical and experimental works from the literature has been presented in this work. This work focuses on the numerical modelling of the natural convection evaporation of an isolated drop of a liquid fuel in natural convection. The transfers in the liquid and vapour phases are described by the conservation equations of mass and species, momentum and energy. The main feature of this work is the consideration of advection, azimuthal angle and thickness of the vapour phase of the drop during evaporation of the drop.展开更多
文摘Methane generation in landfills and its inadequate management represent the major avoidable source of anthropogenic methane today. This paper models methane production and the potential resources expected (electrical energy production and potential carbon credits from avoided CH4 emissions) from its proper management in a municipal solid waste landfill located in Ouagadougou, Burkina Faso. The modeling was carried out using two first-order decay (FOD) models (LandGEM V3.02 and SWANA) using parameters evaluated on the basis of the characteristics of the waste admitted to the landfill and weather data for the site. At the same time, production data have been collected since 2016 in order to compare them with the model results. The results obtained from these models were compared to experimental one. For the simulation of methane production, the SWANA model showed better consistency with experimental data, with a coefficient of determination (R²) of 0.59 compared with the LandGEM model, which obtained a coefficient of 0.006. Thus, despite the low correlation values linked to the poor consistency of experimental data, the SWANA model models methane production much better than the LandGEM model. Thus, despite the low correlation values linked to the poor consistency of the experimental data, the SWANA model models methane production much better than the LandGEM V3.02 model. It was noted that the poor consistency of the experimental data justifies these low coefficients, and that they can be improved in the future thanks to ongoing in situ measurements. According to the SWANA model prediction, in 27 years of operation a biogas plant with 33% electrical efficiency using biogas from the Polesgo landfill would avoid 1,340 GgCO2e. Also, the evaluation of revenues due to electricity and carbon credit gave a total revenue derived from methane production of US$27.38 million at a cost of US$10.5/tonne CO2e.
文摘Introduction: Worldwide, 2.3 million children died in the first 20 days after birth in 2022, according to the WHO. In Mali, according to the sixth Demographic and Health Survey, the neonatal mortality rate was estimated at 33% live births in 2018. The Timbuktu region had the highest neonatal mortality rate in the country with 44%. The objective of this work was to study the causes of neonatal morbidity and mortality and related factors in the paediatrics department of Timbuktu hospital. Materials and method: This was a descriptive, cross-sectional study conducted from 1 January to 31 December 2023 in the neonatology unit of the paediatrics department of Timbuktu hospital, including all newborns admitted to hospital. Results: Our study took place over 12 months, during which 618 admissions were made to the paediatric ward, including 244 newborns, i.e. 39.48%. The majority of newborns (86.5%) were admitted in the first week of life. The mean age was 3 days, with a sex ratio of 1.1 for males. Weight under 2500 g was 54.1% for an average weight of 2372 g. The main mode of admission was transfer from the hospital maternity unit (62%). The main reasons for admission were acute foetal distress (27.9%) and prematurity (26.2%). The average age of the mothers was 24, with extremes of 15 and 49. The mothers were housewives (87.3%), uneducated and primiparous (59% and 36.5% respectively);only 40.2% had made more than 3 antenatal care visits. Newborns born by vaginal delivery accounted for 80.7% and those born by caesarean section for 19.3%. The risk of infection was present in 52.5% of cases. The three leading causes of hospitalisation were birth asphyxia (40.2%), neonatal infection (32.4%) and prematurity (25%). The mortality rate was 21.7%. The main causes of death were prematurity (39.6%), birth asphyxia (32.1%) and neonatal infection (24.5%). Conclusion: Neonatal morbidity and mortality remain a concern in Timbuktu. Despite the unfavourable security situation, morbidity and mortality indicators are close to those in some hospitals in Mali. The correct application of Essential Newborn Care and antenatal care remains a major challenge for the hospital and the Timbuktu region.
文摘The accelerated depletion of oil reserves and the often exorbitant cost of fossil fuels contribute to the development of fuels from renewable sources. The objective of this work is to analyze the influence of the properties of renewable fuels on their evaporation in natural convection, their combustion and their use in internal combustion engines. A summary of the various numerical and experimental works from the literature has been presented in this work. This work focuses on the numerical modelling of the natural convection evaporation of an isolated drop of a liquid fuel in natural convection. The transfers in the liquid and vapour phases are described by the conservation equations of mass and species, momentum and energy. The main feature of this work is the consideration of advection, azimuthal angle and thickness of the vapour phase of the drop during evaporation of the drop.