118 research outputs found

    Les constructions applicatives en seereer singandum

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    La construction applicative est au centre du débat linguistique. Cependant il n’existe pas d’études typologiques d’envergure relatives aux langues africaines. Cet article s’inscrit dans une perspective générale en se fondant sur les données particulières du seereer pour contribuer à l’établissement des données fiables à des fins comparatives. Notre démarche est intégrative. Après avoir défini la construction applicative, nous examinons le comportement de ses différents marqueurs au niveau syntaxique avec successivement les verbes intransitifs, transitifs. Nous tentons ensuite de cerner les rôles sémantiques que ces suffixes assument dans la chaîne parlée

    Suspensions turbulentes de particules de tailles finies : dynamique, modifications de l’écoulement et effets collectifs

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    The evolution of plankton in the ocean, the mixing and deposition of sediments in rivers or the manufacture of some food products imply the transport of finite-size, neutrally buoyant material particles by a turbulent flow. Despite the numerous natural and industrial processes where they appear, the dynamics of such particles is still not fully understood. In particular, there is no acceptable model either for their motion or for the manner with which they perturb the carrier flow. The numerical and experimental work of this thesis contribute to a better understanding of such aspects. A first part is dedicated to study numerically the dynamics of isolated spherical particles. I have developed analysis tools that allowed me to quantify their relative motion to the fluid and their local influence on the turbulent flow. A second part concerns the collective effects of a large number of particles onto turbulence. For that, I have performed experimental particle-tracking measurements in a von Kármán flow seeded with various particles volume fractions. The main result is a tendency for the particles to attenuate the amplitude of turbulent fluctuations. At variance, the particles have no influence on the fine statistical properties of the flow. Also, these measurements suggest the large scales of the flow undergo a phase transition at volume fractions above a critical threshold.L’évolution du plancton dans les océans, le mélange et la déposition de sédiments dans les cours d’eau ou encore la fabrication de certains produits agroalimentaires impliquent le transport de particules matérielles de taille finie et de flottabilité nulle par un écoulement turbulent. Malgré les nombreux processus naturels et industriels où elles interviennent, la dynamique de telles particules reste à ce jour mal comprise. En particulier, il n’existe pas de modèle adéquat pour leur mouvement ou la façon dont elles perturbent le fluide porteur. Les travaux numériques et expérimentaux de cette thèse contribuent à une meilleure compréhension de tels aspects. Un premier volet est consacré à l’étude numérique de la dynamique de particules sphériques isolées. J’ai notamment développé des outils d’analyse qui m’ont permis de quantifier leur mouvement relatif au fluide ainsi que leur influence locale sur l’écoulement turbulent. Un second volet porte sur les effets collectifs d’un grand nombre de grosses particules sur la turbulence. Pour cela j’ai effectué des mesures expérimentales par suivi lagrangien dans un écoulement de von Kármán ensemencé avec différentes fractions volumiques de particules. Le résultat principal est que les particules ont tendance à atténuer l’amplitude des fluctuations turbulentes. En revanche, celles-ci n’ont pas d’influence sur les propriétés statistiques fines de l’écoulement. Aussi, ces mesures suggèrent l’existence d’une transition de phase dans les grandes échelles de l’écoulement pour des fractions volumiques de particules au delà d’un seuil critique

    Archaeological Investigations of Early Trade and Urbanism at Gao Saney (Mali)

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    Excavations at the mound site of Gao Saney, located near the historic town of Gao eastern Niger Bend, Mali, revealed over six meters of domestic deposits and debris from secondary processing of glass and copper dating to the period 700--1100 A.D. This is 200-300 years earlier than anticipated and points to the early development oflong distance trade networks. Lead isotope analysis of copper and glass samples using LAICP- MS points to multiple sources areas, including copper ores in Tunisia and glass production areas in the Middle East. Secondary processing of copper and glass took place at the site, and a substantial portion ofthe sequence comprised mud brick structures and associated domestic trash and wall collapse episodes. The distinctive polychrome pottery assemblage found in the Gao Saney deposits occurs along a 500 km stretch of the Niger Bend between Bentia to the south and Timbucktu to the west, where it appears suddenly and intrusively c. 650-700 A.D. This thesis documents the excavations and the material culture, chronology, subsistence economy and production activities at the site. It argues that the findings support the identification of Gao Saney with the trading town Sarneh mentioned in a tenth century Arab chronicle. The relationship of Gao Saney to Gao Ancien, the putative "royal town" of Kawkaw, is considered through a comparison of material excavated from a massive stone building complex there with the material from Gao Saney. The first millennium pottery at both sites is identical, but elite goods and stone architecture are present in abundance only at Gao Ancien. The evidence supports the identification of a royal town linked to Gao Saney by market and trade relations linked to early long-distance trade

    Suspensions turbulentes de particules de tailles finies : dynamique, modification collective de l'Ă©coulement turbulent

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    The numerical and experimental work of this thesis contribute to a better understanding of the dynamics of large particles in a turbulent flow. The first part allowed me to quantify their relative motion to the flow and their local influence on the surrounding flow. In a second part, I found that the collective effect of particles is to reduce the amplitude of turbulent fluctuations. In revanche, they have no influence on the fine statistical properties of the flow. Also, these measurements suggest the existence of a phase transition in the larger scales of the flow beyond a critical threshold of the number of particles.Les travaux numériques et expérimentaux de cette thèse contribuent à une meilleure compréhension de la dynamique de grosses particules dans un écoulement turbulent. Un premier volet m’a permis de quantifier leur mouvement relatif au fluide, ainsi que leur influence locale sur l’écoulement turbulent. Dans un second volet, j'ai trouvé que l'effet collectif des particules est d'atténuer l’amplitude des fluctuations turbulentes. En revanche, celles-ci n’ont pas d’influence sur les propriétés statistiques fines de l’écoulement. Aussi, ces mesures suggèrent l’existence d’une transition de phase dans les grandes échelles de l’écoulement au-delà d’un seuil critique du nombre de particules

    Collaborative Processes Behavioral Modeling

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    Software engineering is a deeply collaborative activity. Therefore, having tasks executed by more than one actor is common. Such collaborative processes allow development teams to be more efficient. They need to be adequately represented in order to serve as a development model (for example in agile developments). For that, we need a dedicated language allowing to model different collaborative situations

    A project management tool for flexible collaboration

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    We propose a flexible way to enact collaborative tasks. For a more intelligent assistance in selecting an execution strategy for a collaborative task, we are investigating : - A language of definition of context elements - An algorithm of pattern recommendation based on context elements values

    Effets de deux plantes aphrodisiatiques africaines Garcinia kola et Turraea heterophylla sur les performances zootechniques et le taux d’inversion sexuelle chez Oreochromis niloticus

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    Dans le but développer une méthode alternative au 17-α -méthytestostérone, les effets de Garcinia kola et Turraea heterophylla sur la production des alevins monosexes mâles de Oreochromis niloticus ont été évaluées. Ainsi, 7200 alevins (0,011 ± 0,002 g) ont été répartis dans 24 happas en raison de 300 poissons/happa, formant 8 traitements en triplicata. Huit régimes alimentaires correspondant chacun à un traitement ont été testés. Les régimes témoins négatif et positif contiennent respectivement 0 et 70 mg de méthyltestostérone/kg. Six régimes dont 3 par plante, contiennent respectivement 10, 20 et 30 g d’extrait/kg. Les lots « lot 10g » et « lot 30g » de T. heterophylla présentent respectivement les meilleures croissances et taux de mâle. Les taux optimaux d’extraits sont de 10 et 30 g/kg respectivement pour la croissance et masculinisation. L’augmentation du pourcentage de mâles est dose-dépendante. Les fortes proportions de mâles sont de 76,82 ± 3,34 % pour T. heterophylla et 65,75 ± 4,19 % pour G. kola. Les meilleurs poids moyens enregistrés pour T. heterophylla et G. kola sont respectivement de 0,919 ± 0,059 et 0,663 ± 0,103 g. Les taux de survie sont compris entre 88 et 95 %. Des études complémentaires détermineront les méthodes d’application, les solvants d’extraction et la durée de traitement appropriés à la production d’alevins monosexes mâles.Mots-clés : Oreochromis niloticus, Plantes aphrodisiaques, Inversion sexuelle, Paramètres zootechniques, Côte d’Ivoire

    Maariyo Tentu: Praising Our Lord

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    The entire manuscript is available for download as a PDF file(s). Higher-resolution images may be available upon request. For technical assistance, please contact [email protected]. Fieldwork Team: Dr. Fallou Ngom (Pricipal Investigator; Director, African Studies Center), Ablaye DiakitĂ© (Local Project Manager), Mr. Ibrahima Yaffa (General Field Facilitator), and Ibrahima Ngom (photographer). Technical Team: Professor Fallou Ngom (Principal Investigator, Project Director and former Director of the African Studies Center at Boston University)), and Eleni Castro (Technical Lead, BU Libraries). This collection of Mandinka Ajami materials is copied as part of the African Studies Center’s African Ajami Library. This is a joint project between BU and the West African Research Center (WARC), funded by the British Library/Arcadia Endangered Archives Programme. Access Condition and Copyright: These materials are subject to copyright and are distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are fully cited using the information below. For use, distribution or reproduction beyond these terms, contact Professor Fallou Ngom ([email protected]). Citation: Materials in this web edition should be cited as: Ngom, Fallou, Castro, Eleni, & DiakitĂ©, Ablaye. (2018). African Ajami Library: EAP 1042. Digital Preservation of Mandinka Ajami Materials of Casamance, Senegal. Boston: Boston University Libraries: http://hdl.handle.net/2144/27112. For Inquiries: please contact Professor Fallou Ngom ([email protected]). For technical assistance, please contact [email protected] / Custodial history: The owner inherited it from his father after his death.The manuscript is a devotional Mandinka Ajami poem dealing with ethics and morality and life in this world and the afterlife. It promotes righetous living

    Khaly Madiakhate Kala: a 19th-century Wolof scholar

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    The entire manuscript is available for download as a PDF file(s). Higher-resolution images may be available upon request. For technical assistance, please contact [email protected]. Fieldwork Team: Dr. Fallou Ngom (Pricipal Investigator; Director, African Studies Center), Ablaye DiakitĂ© (Local Project Manager), Mr. Ibrahima Yaffa (General Field Facilitator), and Ibrahima Ngom (photographer). Technical Team: Professor Fallou Ngom (Principal Investigator, Project Director and former Director of the African Studies Center at Boston University)), and Eleni Castro (Technical Lead, BU Libraries). This collection of Mandinka Ajami materials is copied as part of the African Studies Center’s African Ajami Library. This is a joint project between BU and the West African Research Center (WARC), funded by the British Library/Arcadia Endangered Archives Programme. Access Condition and Copyright: These materials are subject to copyright and are distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are fully cited using the information below. For use, distribution or reproduction beyond these terms, contact Professor Fallou Ngom ([email protected]). Citation: Materials in this web edition should be cited as: Ngom, Fallou, Castro, Eleni, & DiakitĂ©, Ablaye. (2018). African Ajami Library: EAP 1042. Digital Preservation of Mandinka Ajami Materials of Casamance, Senegal. Boston: Boston University Libraries: http://hdl.handle.net/2144/27112. For Inquiries: please contact Professor Fallou Ngom ([email protected]). For technical assistance, please contact [email protected] / Custodial history: The owner inherited it from his father after his death.The manuscript is an Arabic poem dealing with important historical events and figures in the 19th century in Senegambia. It tells the story of Khaly Madiakhate Kala who was one of the leading Wolof scholars, and his relationship with Lat Dior Ngone Latyr Diop, the last Wolof king who took arms against French colonization
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