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Livestock induces strong spatial heterogeneity of soil CO2, N2O and CH4 emissions within a semi-arid sylvo-pastoral landscape in West Africa

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Journal of Arid Land 2017年第2期9卷 210-221页

作者： Mohamed H ASSOUMA Dominique SERCA Frederic GUERIN Vincent BLANFORT Philippe LECOMTE ibra toure Alexandre ICKOWICZ Raphael J MANLAY Martial BERNOU Jonathan VAYSSIERES CIRAD-UMR Selmet Campus International Baillarguet Montpellier 34398 France DP PPZS ISRA-LNERV BP 2057 Dakar Hann Senegal Laboratoire d'Aerologie-OMP Universite Paul Sabatier 14 Avenue Edouard Belin Toulouse 31400 France Geosciences Environnement Toulouse UMR 5563 & UR 234 IRD Universite Paul Sabatier Avenue Edouard Belin 14 Toulouse 31400 France CILSS 03 BP 7049 Ouagadougou Burkina Faso AgroParisTech-UMR Eco&Sols 2 place Viala Montpellier SupAgro Montpellier 34060 France IRD-UMR Eco&Sols 2 place Viala Montpellier SupAgro Montpellier 34060 France

Greenhouse gas （GHG） emissions from the surface soils and surface water receiving animal excreta may be important components of the GHG balance of terrestrial ecosystems, but the associated processes are poorly documented in tropical environments, especially in tropical arid and semi-arid areas. A typical sylvo-pastoral landscape in the semi-arid zone of Senegal, West Africa, was investigated in this study. The study area （706 km2 of managed pastoral land） was a circular zone with a radius of 15 km centered on a borehole used to water livestock. The landscape supports a stocking rate ranging from 0.11 to 0.39 tropical livestock units per hectare depending on the seasonal movements of the livestock. Six landscape units were investigated （land in the vicinity of the borehole, natural ponds, natural rangelands, forest plantations, settlements, and enclosed plots）. Carbon dioxide （CO2）, nitrous oxide （N2O） and methane （CH4） fluxes were measured with static chambers set up at 13 sites covering the six landscape units, and the 13 sites are assumed to be representative of the spatial heterogeneity of the emissions. A total of 216 fluxes were measured during the one-year study period （May 2014 to April 2015）. At the landscape level, soils and surface water emitted an average 19.8 t C-CO2 eq/（hm2.a）（CO2： 82%, N2O： 15%, and CH4： 3%）, but detailed results revealed notable spatial heterogeneity of GHG emissions. CO2 fluxes ranged from 1148.2 （±91.6） mg/（m2.d） in rangelands to 97,980.2 （±4,861.7） mg/（m2.d） in surface water in the vicinity of the borehole. N2O fluxes ranged from 0.6 （±0.1） mg/（m2.d） in forest plantations to 22.6 （±10.8） mg/（m2.d） in the vicinity of the borehole. CH4 fluxes ranged from -3.2 （±0.3） mg/（m2.d） in forest plantations to 8788.5 （±2295.9） mg/（m2.d） from surface water in the vicinity of the borehole. This study identified GHG emission ＂hot spots＂ in the landscape. Emissions from the surface soils were significantly higher in the landscape units most freq

关键词： greenhouse gases soil surface water livestock landscape Senegal

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Analysis of Bushfires Spatial and Temporal Variability in Guinea

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Atmospheric and Climate Sciences 2017年第4期7卷 463-475页

作者： Tamba Nicolas Millimono Saidou Moustapha Sall Daouda Badiane Alassane Bah Moussa Diakhate ibra toure Mamadou Bailo Barry Diakaria Diallo Idrissa Diaby Institut Superieur des Sciences de l’Education de Guinee(ISSEG) ConakryGuinea Laboratoire de Physique de l’Atmosphere et de l’Ocean-Simeon Fongang-UCAD/ESP/LAPOSF DakarSenegal Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement(CIRAD) OuagadougouBurkina Faso Laboratoire d’Enseignement et de Recherche en Energetique Appliquee-UGANC/LEREA ConakryGuinea

Guinea is confronted to the increasing risks of bushfires that destroy thousands of hectares of vegetation cover every year. Very little research is devoted to the variability of those fires, which makes it a serious threat to both wildlife and human habitats. The current study investigates the spatial and temporal distribution of bushfires in the period from 2003 to 2016. The method used is the geospatial technology: we first filter pixels corresponding with active light supplied by MODIS images (Moderate Resolution Imaging Spectroradiometer) and estimate their densities following the square meshing procedure. Burned areas are deducted from the estimated pixel densities by calculations. The results highlight great occurrence of fires: 4 to 48 pixels of active fire per year and per 100 km2 depending on the location;2 to 5 million hectares per year of burned areas (20,000 to 50,000 sqkm). Almost 8 to 24% the size of the whole country. The prefectures of Beyla, Siguiri, Kouroussa, Kankan, Dinguiraye, Mali and Tougué are the most exposed areas. Every year, fire activities are observed as from October and between May and June. They are however mitigated according to the regions (or the geographical domains). Summits of bushfires activities are generally reached between December and January.

关键词： Guinea Bushfires Variability MODIS

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Frontal Sinus Fractures: Management at the Yalgado Ouedraogo University Hospital Centre (Burkina Faso)

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Open Journal of Stomatology 2024年第1期14卷 42-54页

作者： Arsène Coulibaly Patrik Gane-Bang Joseph Wend-Toin Biogo ibraïma Traoré Tarcissus Konsem Department of Maxillofacial Surgery Regional University Hospital Centre of Ouahigouya Ouahigouya Burkina Faso Department of Stomatology and Maxillofacial Surgery Regional Hospital Centre of Banfora Banfora Burkina Faso Department of Neurosurgery Regional University Hospital Centre of Ouahigouya Ouahigouya Burkina Faso Department of Stomatology and Maxillofacial Surgery Souro SANOU University Hospital Centre Bobo Dioulasso Burkina Faso Department of Stomatology and Maxillofacial Surgery Yalgado OUEDRAOGO University Hospital Centre Ouagadougou Burkina Faso

Introduction: Frontal sinus fractures are potentially serious. They are defined as a solution of continuity, open or closed, of one or both bone tables of the frontal sinus. This study aims to report on the management of them at the Yalgado OUEDRAOGO University Hospital Centre. Methodology: It is a descriptive cross-sectional study with retrospective collection from January 01, 2016 to December 31, 2018. Patients with frontal sinus fractures were managed at the Yalgado OUEDRAOGO University Hospital Centre through CT-scan proof. Results: Over three years, a total of 102 cases of frontal sinus fractures were collected with 29.9 years as average age. There were 96 men. Workers in the informal sector and pupils/students represented 58.90% of patients. The residence of the patients was urban in 68.80% of cases and rural in 31.40%. Road traffic accidents (RTAs) happened in 90.20%, and involved 2-wheelers in 98.20%. None of these drivers was wearing a helmet. The type III frontal fracture of Ioannides et al. represented 51.9% of cases. In 89.21% of cases, other facial and/or cranioencephalic injuries were compounded to frontal sinus fractures. No surgical management was observed in 82 (80.39%) patients and surgical management in 20 (19.61%) patients. The outcome was favourable, but sequelae and/or complications were noted in 10 patients who had surgery and 30 patients who did not. Conclusion: These results enforce helmet wearing for all riders of two-wheeled machines. In addition, vaccinations to prevent meningitis in frontal sinus fractures with dural breach should be systematic.

关键词： Management Frontal Sinus Fracture Burkina Faso

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Numerical investigation on self-priming process of self-priming pump

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排灌机械工程学报 2020年第11期38卷 1113-1118页

作者： FALL ibra PAN Zhongyong ZHANG Desheng DESMOND Appiah ALI Asad YANG Bo National Research Center of Pumps Jiangsu UniversityZhenjiangJiangsu 212013China

In order to investigate the self-priming process of the self-priming pump,an unsteady simulation was conducted where the Navier-Stokes equations were used with the Lagrangian-Eularian *** course of this investigation,the volume fractions,pressure distribution and self-priming time were carried *** analyzing the volume,velocity and pressure distribution of the gas-liquid two-phase flow at different time,the two-phase content via the variation law of the two-phase flow in the pump was carried *** monitoring and analyzing the gas-liquid flow at the outlet of the pump,the self-priming time and crucial periods were *** phenomena were mainly characterized by the self-priming process such as the gas-liquid mixing and separation,which occur in the early stage of self-priming *** that period the gas-liquid mixing clouds appear on the outer edge of the impeller,and the instantaneous void fraction at the inlet and outlet of the impeller decreases *** was also established from the transient study that the gas has a major influence on the hydraulic performance of the pump at the early stage of *** increase the usage of self-priming pump and to also understand the energy conversion of the pump,it is very essential to investigate and establish the basic working principle of the self-priming pump.

关键词： self-priming pump self-priming process numerical simulation

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市政排涝自吸泵启动过程气液两相流动及压力脉动分析

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江苏大学学报（自然科学版） 2020年第5期41卷 516-522页

作者：杨波潘中永 ibra FALL 江苏大学国家水泵及系统工程技术研究中心江苏镇江212013

为了探明自吸泵的自吸机理.以外混式自吸泵为研究对象,利用CFX仿真软件中的VOF(volume of fluid)两相流模型和k-ε湍流模型,并结合网格滑移技术进行自吸过程非稳态数值模拟,分析了不同时刻下泵内气液两相体积、液相速度、出口气体体积... 详细信息

为了探明自吸泵的自吸机理.以外混式自吸泵为研究对象,利用CFX仿真软件中的VOF(volume of fluid)两相流模型和k-ε湍流模型,并结合网格滑移技术进行自吸过程非稳态数值模拟,分析了不同时刻下泵内气液两相体积、液相速度、出口气体体积分数和压力的分布情况.同时改变非稳态模拟的时间步长及总时长,监测自吸过程叶轮及蜗壳内监测点的压力变化.结果表明:自吸泵的吸气与排气主要集中在启动过程的初期和中期,叶轮入口和泵出口的气体体积分数分别超过60%和75%;叶轮出口的气液混合带导致了叶轮出口到蜗壳内侧大片区域内的流动紊乱现象,降低了叶轮的做功能力,进而影响了泵的正常排气;叶轮监测点压力脉动幅值与距叶片工作面的大小有关,蜗壳内监测点压力脉动幅值与距叶轮外缘的大小有关.

关键词：自吸泵气液两相流非定常数值模拟压力脉动瞬时体积分数

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Numerical Investigation on the Self-priming Process of A Self-priming Centrifugal Pump

Numerical Investigation on the Self-priming Process of A Sel...

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作者： ibra fall 江苏大学

学位级别：硕士

自吸泵是一种效率低、自吸能力强的水力机械。由于其独特的自吸能力,在建筑、石化、化工、消防、采矿等领域得到了广泛应用。长久以来,自吸离心泵的设计已经过多次改进。但是与其他叶片泵相比,效率较低依然是自吸泵的主要缺点。虽然本... 详细信息

自吸泵是一种效率低、自吸能力强的水力机械。由于其独特的自吸能力,在建筑、石化、化工、消防、采矿等领域得到了广泛应用。长久以来,自吸离心泵的设计已经过多次改进。但是与其他叶片泵相比,效率较低依然是自吸泵的主要缺点。虽然本文的主要目的是研究自吸离心泵的自吸过程,但也对其两相流动特性和压力波动进行了研究,以期为今后的改进提供参考。首先,采用Langrange和Euler模型对自吸泵进行数值计算。在这一数值方法中,结合泵的实际运行情况进行了仿真研究。在泵送的初期阶段,吸入的气体是在自吸过程中由泵输送的。从流动特性上看,两室（分离室和储存室）起着主要的作用,尤其是分离室。实验和数值的性能不确定性近似4.4%近似。此外,在不同的工况下给出包括质量流量,压力波动和湍动能强度的物理参数,以分析内部流动特性。泵中的气体消耗更多的输入功率,从而降低了泵的性能。初期,泵出口的空气体积分数迅速下降了约50%,而进口的空气体积分数迅速上升,且均随单相流量在3s左右波动至零。在自吸初期,大量气泡包裹在叶轮外缘,形成涡流分布。研究发现,在自吸过程的初期,由于涡流混合过程和两相流相互作用等不稳定性,压力分布较低。由于混合过程,叶轮进口的空气体积分数比泵出口空气体积分数的低。自吸过程结束后,压力升高,因为是单相流量（水）,相应的自吸时间为3s。蜗壳叶轮界面压力脉动强度幅值达到最大值,然后沿径向减小或向内半径移动减小。从外叶轮半径到内半径,湍流动能也随时间增加,并且在3s的周期内,由于单向流动,湍流动能增加。本文的工作还可以通过以下研究进一步完善:（1）储存室内的初始含水量的影响;（2）自吸泵回流孔的最佳位置和尺寸;（3）优化叶轮与蜗壳舌之间的间隙的作用,现有研究结果表明,叶轮通过蜗壳时,蜗壳处出现压力波动的最大峰值。

关键词：自吸离心泵自吸过程数值研究

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斯里兰卡东部省2004年海啸灾难幸存者的聚居地安置

斯里兰卡东部省2004年海啸灾难幸存者的聚居地安置

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作者： FAJRUTHEEN ibra Lebbe 同济大学

学位级别：硕士

The 2004-Tsunami disaster in Sri Lanka is one of the most significant landmarks in the history of the country. Restoration of the normal life of the disaster survivors is the upper most concern among the other post-disaster needs. The government's country wide post-tsunami declaration of a lengthy buffer zone as No-Living Zone has added further more to the challenges of bringing the affected people to their normal life.Following the declaration, the literatures and the arguments on it have illustrated the confusion and hardship in the implementation of the declaration in the coast line of Sri Lanka in general. They argue that the declaration limits the social and spatial scope of the survivors' residency. It has banned the people to resettle in their former places within 200m from the seashore. Here the main issue is that either relocating the survivors miles away from their former places or resettling them in the same place where they lived before Tsunami.The main aim of our studies is to confirm the resettlement location for the survivors of the eastern coast line of Sri Lanka as this province has sustained the highest devastation in the disaster. By carefully investigating the geographical aspects such as socio-economy, politics, land, culture and environment of the Eastern Province, our studies justify the resettlement of the survivors rather than relocating them miles away from their former places. And in our studies, suggestions and recommendations are made with the view to utilizing the coastal zone in more sustainable ways in the future.

关键词： Buffer Zone No-Living Zone Geographical aspects Relocation Resettlement

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一种新型数字式相位计

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国外电子测量技术 1989年第2期8卷 23-29页

作者： ibra,KM 孙继

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塞内加尔留学生习得汉语复合趋向补语的偏误分析及教学对策

塞内加尔留学生习得汉语复合趋向补语的偏误分析及教学对策

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作者：艾力蒙（NDIAYE ELIMANE ibra）辽宁师范大学

学位级别：硕士

很多塞内加尔留学生对学习汉语很感兴趣,但是在习得汉语补语的过程中,常常遇到很多困难,尤其是在习得汉语复合趋向补语时,问题更多。由于汉语、法语两种语言语法结构差异较大,塞内加尔留学生在使用复合趋向补语时,会产生各种各样的偏误... 详细信息

很多塞内加尔留学生对学习汉语很感兴趣,但是在习得汉语补语的过程中,常常遇到很多困难,尤其是在习得汉语复合趋向补语时,问题更多。由于汉语、法语两种语言语法结构差异较大,塞内加尔留学生在使用复合趋向补语时,会产生各种各样的偏误。本文以塞内加尔留学生为研究对象,运用问卷调查法、偏误分析法,和对比分析法,在问卷调查的基础上,深入分析了塞内加尔留学生在习得汉语复合趋向补语时经常出现的偏误。根据调查结果把偏误类型分为四种,即误加、遗漏、混淆、错序。其次,根据调查语料以及自己的学习实践,分析了偏误产生的原因。主要包括两个方面,即母语负迁移的影响和趋向补语本身的复杂性。最后,提出相应的教学对策。建议教师在教学时,以学生为中心,注重结构对比,加强语义教学,设置趣味情境。期望本论文的研究可以帮助塞内加尔留学生明白习得复合趋向补语时经常出现的问题,了解产生这些问题的原因,克服在习得复合趋向补语过程中遇到的困难,更好的掌握这个知识点,提高自己的汉语水平。也希望能够为对外汉语教师的教学和教材的编写提供帮助。

关键词：塞内加尔留学生复合趋向补语偏误分析教学对策

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Wild Fruits Traditionally Gathered by the Malinke Ethnic Group in the Edge of Niokolo Koba Park (Senegal)

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American Journal of Plant Sciences 2014年第9期5卷 1306-1317页

作者： Mathieu Gueye Nicolas Cyrille Ayessou Souleye Koma Seydina Diop Leonard Elie Akpo Papa ibra Samb Department of Plant Biology Faculty of Science and Technology UCAD Dakar Senegal Laboratoire de Formation Continue en Industries Agroalimentaires Ecole Supérieure Polytechnique Université Cheikh Anta Diop Dakar Senegal Laboratory of Botany Department of Botany and Geology UMI 3189 IFAN Ch. A. Diop Dakar Senegal

In rural areas, the local population draws from several forest resources needed for survival including food. Then it is a granary for these native people. Unfortunately, useful wild plants are highly threatened, especially by various human activities. Because of this situation we started with open semi-structured interviews to identify wild fruit plants, their consumed organs and their seasonality in the rural community of Tomboronkoto. Tomboronkoto is located at the edge of the Niokolo-Koba National park (Senegal) and is mainly inhabited by Malinke. We identified 45 wild fruit species belonging to 38 genera that can be divided in 28 botanical families. The more diversified are successively the Anacardiaceae, Tiliaceae, Apocynaceae and Caesalpiniaceae. More than half of the plants inventoried are trees (53%). We can distinguish three categories of fruits depending on their Fidelity Level (FL) that informs us about their popularity: the well-known or common fruits, moderately known fruits and little known fruits. A dozen wild fruits happen to be greatly appreciated with very high fidelity level (100% to 84%). The fruits of Saba senegalensis, Adansonia digitata, Parkia biglobosa, Tamarindus indica and Vitellaria paradoxa are the most variously used because they are appreciated being fresh or cooked. Only fruits of Ficussur are available all year long. The large majority of the most consumed fruits are available between the end of the hot dry season until the middle of the rainy season. This period coincides with the period where crops from the previous rainy season are depleted and the new crops are not yet ripe. Thus, these wild fruits would greatly contribute to food security in this area during the lean period.

关键词： Ethnobotany Traditional Knowledge Wild Edible Fruits Malinke Senegal

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