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Relationships between soil seed banks and above-ground vegetation along a disturbance gradient in the W National Park trans-boundary biosphere reserve,West Africa

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Journal of Plant Ecology 2017年第2期10卷 349-363页

作者： Patrice savadogo Lassina Sanou SDjibril Dayamba Fidele Bognounou Adjima Thiombiano World Agroforestry Centre and International Crop Research Institute for the Semi-Arid Tropics(ICRAF-ICRISAT) West and Central Africa Region-Sahel NodeBP 12404 NiameyNiger Centre National de la Recherche Scientifique et Technologique INERADépartement Productions Forestières03 BP 7047Ouagadougou 03BurkinaFaso Unitéde Formation et de Recherche en Sciences de la Vie et de la Terre/Laboratoire de Biologie et Ecologie Végétales(UFR/SVT) Universitéde Ouagadougou03 BP 7047Ouagadougou 03BurkinaFaso World Agroforestry Centre(ICRAF) West and Central Africa Regional Office-Sahel NodeBP E5118 BamakoMali Département des Sciences Biologiques Université´du QuébecàMontréal2080 rue Saint Urbain8888Montréal QC H3C 3P8Canada

Aims Vegetation succession depends on the availability of suitable prop-agules in the soils,thus knowledge of soil seed banks is essential for formulating effective strategies for restoring the vegetation of degraded *** W National Park,the only trans-boundary bio-sphere reserve in West Africa,is being extensively fragmented and degraded in recent *** aims of this study were to assess the reserve’s soil seed banks,their relationships with standing veg-etation and bundle of disturbances and their potential significance for vegetation *** The size and composition of the above-ground species vegetation were assessed in nine plots of 1 ha each representing a range of habitats with differing disturbance severity(low,intermediate and high).A total of 702 soil samples were taken from three layers(0-3,3-6 and 6-9 cm)and soil seed bank was analyzed using the seed-ling emergence *** Findings Generally,seeds of non-woody taxa dominated in samples from all soil depths and habitats of all disturbance *** mean soil seed density was 17.8,24.4 and 26.3 seeds/dm^(3) in samples from the least,intermediate and most disturbed sites,respectively,and highest in the upper soil layers in all *** results indi-cate that there is limited potential for restoring woody vegetation solely from soil seed banks,and that woody species in the region rely more on recently shed seeds trapped in the standing dead biomass and litter on the ground than soil seed banks for ***,human intervention is needed to accelerate forest recovery,mainly through alleviating anthropogenic impacts on the ecosystem(for instance,avoiding destruction of new seeds by intense fire),and site manipulation to improve environmen-tal conditions for seedling establishment and *** ways of restoring forests than through the soil seed bank(*** seeds collected elsewhere,and planting tree seedlings)could also be relevant.

关键词： disturbance savanna-woodland restoration regeneration seed bank vegetation degradation West Africa

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Analysis and Comparison of Doping Level Effects on a Crystalline Silicon PV Cell under Both Moderate Light Concentration and Normal Illumination Modes

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Energy and Power Engineering 2022年第10期14卷 523-540页

作者： Mahamadi savadogo Adama Ouedraogo Boubacar Soro Zi Daouda Koudougou Martial Zoungrana Issa Zerbo Laboratory of Thermal and Renewable Energies Department of Physics Unit of Training and Research in Pure and Applied Sciences University Joseph Ki-Zerbo Ouagadougou Burkina Faso Centre Universitaire Polytechnique de Kaya (CUP-Kaya) Kaya Burkina Faso Institut des Sciences et Technologies Ouagadougou Burkina Faso

The main purpose of this work is to study doping level effects on a silicon PV cell under both moderate light concentration and normal illumination. This study also aims to compare the doping level effects under the both illumination modes. The results show for both illumination modes that diffusion parameters decrease with increasing doping level. These results are in agreement with the studies of the current and the voltage which showed for the two illumination modes that doping level increase leads to a decrease in current density and an increase in voltage. It also emerges for the two illumination modes and for the doping range 1013 cm-3 - 1016 cm-3, a decrease of maximum power and conversion efficiency. The results also show that decrease of diffusion parameters is faster under moderate concentration in comparison with normal illumination. These results predict a greater variation rate of the current, the voltage, the maximum power and the conversion efficiency under moderate concentration compared to normal illumination. Contrary to diffusion parameters study, the results show higher variation rates of parameters under normal illumination. This is explained by the fact that under moderate concentration, carriers density is close to doping level: the cell is then in high injection condition. Consequently, under moderate concentration, carriers density is less sensitive to doping level variations. The study confirms that carriers density variation with the doping level is weak under the moderate concentration compared to normal illumination.

关键词： Moderate Light Concentration Doping Level High Injection Diffusion Parameters Conversion Efficiency

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Perspectives in restoration: storage and pretreatments of seeds for better germination of Sudanian savanna-woodland species

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Journal of Forestry Research 2016年第4期27卷 773-778页

作者： S.D.Dayamba P.savadogo S.Diawara L.Sawadogo World Agroforestry Centre (ICRAF) West and Central Africa Regional Office - Sahel Node World Agroforestry Centre & International Crop Research Institute for the Semi-Arid Tropics (ICRAF-ICRISAT) West and Central Africa Region-Sahel Node De'partement Productions Forestie`res Centre National de la Recherche Scientifique et Technologique Institut de l’Environnement et de Recherches Agricoles

Insufficient knowledge of the germination ecology of local species is one of the main constraints to restoration of degraded rural lands. We tested seeds from fourteen Sudanian savanna species targeted for restoration for their response to two different pretreatments（conventional and prolonged acid pretreatments） and two different storage conditions（ambient room conditions and refrigerator at 4 C）. For 6 of the studied species, longer soaking in sulphuric acid significantly improved germination rates and also reduced the germination time of some species. Storage condition, in general did not affect germination rates except for two species where cool storage depressed germination. The practical implication is that, for the species tested, when mature seeds are collected for plantation in the upcoming rainy season, there is no need to invest in infrastructure and energy for storing in cold *** study also revealed that in general when seeds are stored in ambient conditions from the time of collection up to seeding time, although germination rate does not increase, germination time is shortened and this could be of great interest in synchronizing germination in real field conditions.

关键词： germination restoration plantation ambient mature stored ecology degraded shortened longer

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直接涂膜技术用于质子交换膜燃料电池膜电极制备 (Ⅱ)

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化工学报 2004年第8期55卷 1324-1328页

作者：蒋淇忠 Oumarou savadogo 马紫峰上海交通大学化学工程系上海200240 蒙特利尔大学工学院电化学与能源材料实验室

研究了直接涂膜过程中 ,催化剂液组成对电池性能的影响 .异丙醇在催化剂墨水中起到溶剂和造孔剂的作用 ,当催化剂墨水中催化剂、异丙醇的质量比为 1∶10时电池性能最好 .Nafion是催化剂层中良好的黏结剂和质子传导载体 .由于直接涂膜 ,... 详细信息

研究了直接涂膜过程中 ,催化剂液组成对电池性能的影响 .异丙醇在催化剂墨水中起到溶剂和造孔剂的作用 ,当催化剂墨水中催化剂、异丙醇的质量比为 1∶10时电池性能最好 .Nafion是催化剂层中良好的黏结剂和质子传导载体 .由于直接涂膜 ,使Nafion液与Nafion膜直接接触 ,从而增加了质子传导性 .实验结果表明 ,最佳的Nafion含量 (干基 )为NFP =33% .通过对不同金属含量的Pt/C催化剂的研究发现 ,金属含量不同 ,异丙醇和Nafion的最优含量亦随之改变 .考察了催化剂层不同制备工艺对电池性能的影响 ,表明催化剂层数越多电池性能越好。

关键词：质子交换膜燃料电池膜电极装备直接涂膜技术

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Investigation of the Behavior of a Photovoltaic Cell under Concentration as a Function of the Temperature of the Base and a Variable External Magnetic Field in 3D Approximation

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Smart Grid and Renewable Energy 2023年第12期14卷 209-220页

作者： Boubacar Soro Adama Ouedraogo Mahamadi savadogo Ramatou Konate Guyserge Tchouadep Martial Zoungrana Sié Kam Laboratory of Thermal and Renewable Energies Department of Physics Université Joseph Ki-Zerbo Ouagadougou Burkina Faso Institutdes Sciences et Technologie Ecole Normale Supérieure Ouagadougou Burkina Faso Centre Universitaire Polytechnique de Kaya Université Joseph Ki-Zerbo Ouagadougou Burkina Faso

The photovoltaic (PV) cell performances are connected to the base photogenerated carriers charge. Some studies showed that the quantity of the photogenerated carriers charge increases with the increase of the solar illumination. This situation explains the choice of concentration PV cell (C = 50 suns) in this study. However, the strong photogeneration of the carriers charge causes a high heat production by thermalization, collision and carriers charge braking due to the electric field induced by concentration gradient. This heat brings the heating of the PV cell base. That imposes the taking into account of the temperature influence in the concentrator PV cell operation. Moreover, with the proliferation of the magnetic field sources in the life space, it is important to consider its effect on the PV cell performances. Thus, when magnetic field and base temperature increase simultaneously, we observe a deterioration of the photovoltage, the electric power, the space charge region capacity, the fill factor and the conversion efficiency. However the photocurrent increases when the base temperature increases and the magnetic field strength decreases. It appears an inversion phenomenon in the evolution of the electrical parameters as a function of magnetic field for the values of magnetic field B> 4×10-4 T.

关键词： Thermalization Base Temperature Magnetic Field Fill Factor Efficiency Space Charge Region Capacity

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直接涂膜技术用于质子交换膜燃料电池膜电极制备

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化工学报 2004年第3期55卷 488-492页

作者：蒋淇忠,马紫峰,Oumarou savadogo 上海交通大学化工系上海交通大学化工系蒙特利尔大学工学院电化学与能源材料实验室上海200240 上海200240 加拿大魁北克省蒙特利尔市6079信箱 H3C3A7

A new membrane electrolyte assembly (MEA) preparation method for polymer electrolyte membrane fuel cell (PEMFC) was developed by applying the directly printing catalyst on membrane *** method was simple and easy to be controlled as verified by repetition experiment. When the membrane with catalyst prepared by the new technique and the electrode with diffusion layer was only sandwiched but not hot pressed, this kind of MEA was called not-hot-press MEA (NPMEA) and its fuel cell performance was better than that of MEA which was hot pressed (HPMEA).The effects of 6 different kinds of solvents in catalyst mixture ink on the performance of fuel cell were *** was discovered that iso-propanol was the best solvent in catalyst mixture ink and showed the best performance of fuel cell. Finally several MEAs prepared by different ways were tested on fuel cell station and it was reported that the performance of MEA prepared by the directly printing catalyst on membrane technique was the best in the whole voltage region.

关键词：质子交换膜燃料电池(PEMFC) 膜电极(MEA) 直接涂膜技术

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Results of the Traditional Treatment of Fractures of Patients Discharged against Medical Advice from the Orthopedics Department of the Ouahigouya Regional University Hospital (Burkina Faso)

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Open Journal of Orthopedics 2022年第1期12卷 1-9页

作者： Mamoudou Sawadogo Salam Ouedraogo Sayouba Tinto Malick Diallo Sibiri Abdoul Karim Bouda Abdourahamane Ouangre Madi savadogo Department of Orthopedics-Traumatology Yalgado Ouedraogo University Hospital Ouagadougou Burkina Faso Surgery Department of the Regional Hospital Ouahigouya Burkina Faso Department of Orthopedics-Traumatology Sourou Sanon University Hospital Bobo-Dioulasso Burkina Faso

Introduction: Binding retains an important place in Africa. Leaving a health facility to see a bonesetter is common there, but a source of complications. The purpose of this work was to analyze the results obtained by bonesetter after discharge against medical advice. Methodology: Analytical cross-sectional study over a period of one year, including all patients admitted for limb fracture, discharged against medical advice for treatment with a bonesetter. Results: Thirty-nine patients were selected. The average age was 36.9 years, and the sex ratio was 5.50. The fractures were open in 35.9%. At a mean follow-up of 19 months, the course was marked by pain in 34.4% and inequality in limb length in 62.5%. Thirteen fractures (40.6%) were consolidated with axis defect, and 11 were without axis defect (34.4%). There were eight non-union (25%), and eleven patients (34.4%) presented with stiffness in one or more joints. Seven patients had died. Discussion: The problem of discharge against medical advice is found in all hospitals but is particularly marked for fractures in our context. The absence of an X-ray and ignorance of the rules of asepsis lead to complications. Only the fractures of the two bones of the leg had progressed well (5/8 good results). The rate of vicious calluses (40.6%) and non-union (25%) is high. Conclusion: Although a few cases have progressed favorably, the results of pat

关键词： Fractures Bonesetter Discharge against Medical Advice

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Performance variability of Ba0.5Sr0.5Co0.8Fe0.2O3-δ cathode on proton-conducting electrolyte SOFCs with Ag and Au current collectors

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Rare Metals 2018年第8期37卷 633-641页

作者： Ting-Ting Wan An-Kang Zhu Hai-Bo Li Chun-Chang Wang You-Min Guo Zong-Ping Shao Oumarou savadogo School of Physics and Materials Science Anhui UniversityHefei 230601China State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemistry and Chemical EngineeringNanjing University of TechnologyNanjing 210009China Department of Chemical Engineering Curtin UniversityPerth W A 6845.Australia Laboratory of New Materials for Electrochemistry and Energy Polytechnique MontrealC.P.6079Succursale Centre-VilleMontr6alQC H3C 3A7Canada

Ba0.5Sr0.5Co0.8Fe0.2O3-δ （BSCF） is one of the most active cathode materials and shows significant hydration effect suggesting possible proton conductivity. In this study, the performance of BSCF cathode on a protonconducting BaZr0.1Ce0.7Y0.2O3-δ（BZCY） electrolyte with silver and gold current collectors was determined. The electrochemical characteristics of the symmetrical and anode-supported cell with diluted silver electrode, silver current collector or gold current collector on BSCF electrode were compared. The significant result is that, although the diluted silver electrode itself shows poor operation stability, the silver current collector has strong electrocatalytic contribution to the BSCF cathode performance on the proton-conducting electrolyte, leading to higher cell performance than that with the gold current collector.

关键词： Solid oxide fuel cell Proton conductor Agcurrent collector Operation stability

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Three-Dimensional Study of the Effect of the Angle of Incidence of a Magnetic Field on the Electrical Power and Conversion Efficiency of a Polycrystalline Silicon Solar Cell under Multispectral Illumination

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Smart Grid and Renewable Energy 2022年第12期13卷 295-304页

作者： Idrissa Sourabié Vinci de Dieu Bokoyo Barandja Mahamadi savadogo Ramatou Konaté Alain Doua Gnabahou Martial Zoungra Issa Zerbo Frédéric Ouattara Laboratoire de Chimie Analytique de Physique Spatiale et énergétique (L@CAPSE) Université Norbert ZONGO Koudougou Burkina Faso Laboratoire d’Energie Thermique Renouvelable (L.E.T.RE) Université Joseph KI ZERBO Ouagadougou Burkina Faso Department of Physics University of Bangui Bangui Central African Republic

A three-dimensional approach to the effect of magnetic field incidence angle on electrical power and conversion efficiency is performed on a front-illuminated polycrystalline silicon bifacial solar cell. A solution of the continuity equation allowed us to present the equations of photocurrent density, photovoltage and electric power. The influence of the angle of incidence of the magnetic field on the photocurrent density, the photovoltage and the electric power has been studied. The curves of electrical power versus dynamic junction velocity were used to extract the values of maximum electrical power and dynamic junction velocity and to calculate those of conversion efficiency. From this study, it is found that the conversion efficiency values increase with the angle of incidence of the magnetic field.

关键词： Angle of Incidence Magnetic Field Electric Power Bifacial Solar Cell Conversion Efficiency

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Schistosoma mansoni and Schistosoma heamatobium Infection and Nutritional Status of Children in the Hydro-Agricultural Complex Zone of Sourou,Burkina Faso

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Occupational Diseases and Environmental Medicine 2014年第2期2卷 13-18页

作者： Leon G.B.savadogo Boubacar savadogo Dayéri Dianou Jean Noel Poda Department of Epidemiology and Public Health—Child and Mother Health Nutrition and Survival UnitInstitut Supérieur des Sciences de la SantéUniversite Polytechnique de Bobo DioulassoBobo DioulassoBurkina Faso Institut de Recherche en Sciences de la Santé OuagadougouBurkina Faso

In developing countries, efforts to face food insecurity were revealed by construction of dams and hydro-agricultural managements. This study aimed to establish sanitary consequences in a hydro- agricultural zone. Methods: Data from 1847 children were analysed. Kato-Katz and concentration in MIF were used for intestinal parasites;research of microscopic haematury was used for urinary schistosomiasis. Nutritional status was estimated by WHZ and HAZ indexes. Association between malnutrition and independents variables was measured in univariate and multivariate analysis. Results: Among children, 80.1% were infested by at least one parasite, 30.8% by S. mansoni and 49.6% by S. haematobium. Prevalence of emaciation and prevalence of stunting were respectively, 32.6% and 25.5%. In the multivariate analysis: Age: (1 - 3 y age group, OR = 2.92, 4 - 6 y age group OR = 1.85, p p = 0.008), were associated with emaciation. Age: (4 - 6 y age group, OR = 1.78, 7 - 11 y age group OR = 2.55, p p = 0.005), were associated with emaciation. Conclusion: Development of bilharziasis (urinary and intestinal) with increased morbidity and malnutrition, attenuate benefits expected from hydro-agricultural managements. It is important to invest in the control of water-related diseases, which are amplified by hydro-agricultural managements.

关键词： Schistosoma Nutritional Status Children Hydro-Agricultural Complex

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