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The Nok culture in central Nigeria, dated 1500–1 cal bc, is known for its famous terracotta sculptures. We here present a study on > 11,000 botanical macro-remains from 50 sites, including 343 samples from Nok contexts and 22 samples dating between cal ad 100 and 400, after the end of the Nok culture. With 9,220 remains, pearl millet (Cenchrus americanus (L.) Morrone, syn. Pennisetum glaucum (L.) R.Br.) is dominant in the Nok samples, followed by cowpea (Vigna unguiculata (L.) Walp.), Canarium schweinfurthii Engl., Nauclea latifolia Sm. (syn. Sarcocephalus latifolius (Sm.) E.A.Bruce), wild fruit trees and wild Poaceae. The pearl millet remains consist exclusively of charred caryopses; chaff remains are completely absent. Because we studied all size fractions, including the small 0.5 mm fractions usually containing the involucres, bristles and husks, the absence of pearl millet chaff is real, excluding a methodological explanation, and distinguishes Nok from contemporary other West African sites. We propose that most excavated Nok sites were consumer sites where clean grain was brought in from outside and consumed in a ritual context connected with feasting. This is in line with the archaeological evidence from the larger excavated sites with stone-pot arrangements that are interpreted as ritual places related to mortuary practices. In addition to the known southward branches of pearl millet diffusion from the Sahara we propose a new, hitherto unknown branch directly from the central Sahara to the central Nigerian savannas.

West African cuisine has long been known for its distinct ingredients and flavours, often enhanced by the addition of a large and diverse range of plant foods. A traditional meal comprises a starchy staple cooked in a pot, served with a sauce prepared from vegetables, fish and/or meat, often accompanied by pulses. However, reconstructing the antiquity of the full range of plant use by ancient peoples, using archaeobotanical remains, in West Africa is challenging due to their somewhat fragile nature. Hence, there is a strong bias toward food plants that survive in charred condition, rendering invisible those that easily decompose, such as leafy plants and tubers. Here, we combine organic residue analysis of 458 prehistoric vessels, with archaeobotanical evidence from ten sites of the prehistoric Nok culture, Nigeria, spanning a period of around 1500 years, beginning around the middle of the second millennium BC and terminating in the last centuries BC. Our results reveal a range of highly diverse and complex lipid distributions denoting the preparation and processing of various plant types, including leafy vegetables or ‘greens’, cereals, pulses and underground storage organs, possibly yams. Here, we render previously unidentifiable leafy plant use visible and suggest an early origin for the plant component of modern-day West African cuisine.

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. The nitrogen isotope compositions of charred wheat and barley grains reflect manuring intensity and have been used to reconstruct past manuring practices at archaeological sites across Europe and western Asia. To assess whether this analytical method can be applied to a staple crop in the West African Sahel, the nitrogen isotope values of Pennisetum glaucum grains in this region were determined and the effect of charring ascertained. Pennisetum glaucum ears were collected from fields in northeast Senegal, where the fertilisation histories of the plots (manure and/or household waste) were known. The nitrogen isotope values of these millet grains provide an insight into the values to expect for P. glaucum grains grown with low to moderate addition of manure/household waste in a semi-arid climate. Charring of P. glaucum grains by heating at 215–260 °C for 4–24 h increases their nitrogen isotope values by a maximum of 0.34‰. In light of these modern data, the nitrogen isotope values of millet grains recovered from the archaeological settlement mound of Tongo Maaré Diabal, Mali, can be interpreted as evidence for modest levels of manure/household waste input throughout the occupation of the site from cal ad 500–1150. This study demonstrates the potential for nitrogen isotope values of P. glaucum grains to shed light on past farming practices in West Africa.

While narratives of the spread of agriculture are central to interpretation of African history, hard evidence of past crops and cultivation practices are still few. This research aims at filling this gap and better understanding the evolution of agriculture and foodways in West Africa. It reports evidence from systematic flotation samples taken at the settlement mounds of Sadia (Mali), dating from 4 phases (phase 0=before first–third century AD; phase 1=mid eighth–tenth c. AD; phase 2=tenth–eleventh c. AD; phase 3=twelfth–late thirteenth c. AD). Flotation of 2200 l of soil provided plant macro-remains from 146 archaeological samples. As on most West African sites, the most dominant plant is pearl millet (Pennisetum glaucum). But from the tenth century AD, sorghum (Sorghum bicolor) and African rice (Oryza glaberrima) appear in small quantities, and fonio (Digitaria exilis) and barnyard millet/hungry rice (Echinochloa sp.), sometimes considered weeds rather than staple crops, are found in large quantities. Some samples also show remains of tree fruits from savannah parklands, such as baobab (Adansonia digitata), marula (Sclerocarya birrea), jujube (Ziziphus sp.), shea butter (Vittelaria paradoxa) and African grapes (Lannea microcarpa). Fonio and Echinochloa sp. cultivation appears here to be a later addition that helped to diversify agriculture and buffer against failures that might affect the monoculture of pearl millet. This diversification at the end of the 1st millennium AD matches with other evidence found in West Africa. Introduction Archaeological background - Localisation and current environment - Chrono-stratigraphy - Important features Material and methods Results - Description of the main economic taxa at Sadia -- Pearl millet, Pennisetum glaucum (L.) R. Br., Poaceae -- Fonio, Digitaria exilis (Kippist.) Staph., Poaceae. -- Barnyard millet/hungry rice, Echinochloa sp., Poaceae -- Sorghum, Sorghum bicolor subsp. bicolor (L.) Moench., Poaceae. -- Cowpea, Vigna unguiculata (L.) Walp., Fabaceae -- Roselle, Hibiscus sabdariffa Lin., Malvaceae -- Fruits, tree and bushes -- Weeds and/or wild gathered plants -- Indeterminate Poaceae species - Diachronic analysis -- Phase 0: ‘pre-tell phase’—before first–third century AD -- Phase 1: mid eighth–tenth c. AD -- Phase 2: tenth–eleventh c. AD -- Phase 3: twelfth–late thirteenth c. AD - Spatial distribution for phase 3 Discussion - Agricultural practices and food preparation -- Pearl millet and sorghum -- Cowpea -- African rice -- Weeds and/or gathered seeds -- Fonio -- Echinochloa -- Tree and shrubs - Sadia and the agricultural diversification of the Dogon Country - Sadia in its regional context Conclusion

International audience; Imprints of domesticated pearl millet (Pennisetum glaucum (L.) R. Br.) spikelets, observed as temper in ceramics dating to the third millennium BC, provide the earliest evidence for the cultivation and domestication process of this crop in northern Mali. Additional sherds from the same region dating to the fifth and fourth millennium BC were examined and found to have pearl millet chaff with wild morphologies. In addition to studying sherds by stereo microscopy and subjecting surface casts to scanning electron microscopy (SEM), we also deployed X-ray micro-computed tomography (microCT) on eleven sherds. This significantly augmented the total data set of archaeological pearl millet chaff remains from which to document the use of the wild pearl millet as ceramic temper and the evolution of its morphology over time. Grain sizes were also estimated from spikelets preserved in the ceramics. Altogether, we are now able to chart the evolution of domesticated pearl millet in western Africa using three characteristics: the evolution of non shattering stalked involucres ; the appearance of multiple spikelet involucres, usually paired spikelets; and the increase in grain size. By the fourth millennium BC, average grain breadth had increased by 28%, although spikelet features otherwise resemble the wild type. In the third millennium BC, the average width of seeds is 38% greater than that of wild seeds, while other qualitative features of domestication are indicated by the presence of paired spikelets and the appearance of non dehiscent, stalked involucres. Non shattering spikelets had probably become fixed by around 2000 BC, while increases in average grain size continued into the second millennium BC. These data now provide a robust sequence for the morphological evolution of domesticated pearl millet, the first indigenous crop domesticated in western Africa.; Des empreintes d’épillets de mil domestiqué (Pennisetum glaucum (L.) R. Br.) observées dans des céramiques datées du 3e millénaire av. J.-C. provenant du nord du Mali constituent les plus anciens témoins de la mise en culture et de la domestication de cette céréale. Des tessons supplémentaires issus de la même région se rapportant aux 5e et 4e millénaires av. J.-C. ont été examinés et ont révélé des empreintes de balle de mil de morphologies sauvages. En plus de l’observation de leurs surfaces par stéréo-microscopie, et de l’observation des moulages d’empreintes au microscope à balayage, onze d’entre eux ont fait l’objet de microtomographies aux rayons X (microCT). Ces examens enrichissent considérablement l’ensemble des données archéologiques concernant l’utilisation du mil sauvage comme dégraissant végétal et son évolution morphologique à travers le temps. La taille des grains a aussi été estimée à partir des épillets conservés dans la céramique. En tenant compte des données enregistrées lors d’études antérieures, nous pouvons désormais retracer l’évolution du mil domestiqué en Afrique de l’Ouest à travers trois caractéristiques : l’évolution des involucres pédonculés à égrenage non-spontané; l’apparition d’involucres multiples par épillets, des épillets appariés le plus souvent; l’augmentation de la taille des grains au vu de leur largeur. Déjà au 4e millénaire avant J.-C., la largeur moyenne des grains a augmenté de 28% bien que les caractéristiques de l'épillet ressemblent au type sauvage. Au 3e millénaire avant J.-C., elle est 38% supérieure à celle du morphotype sauvage, tandis que des caractéristiques qualitatives de la domestication sont avérées par la présence d’épillets appariés et par celle d’involucres pédonculés à égrenage nonspontané. La non-déhiscence des épillets est un caractère de domesticité qui s’est probablement fixé vers 2000 avant J.-C. L’augmentation de la taille moyenne des grains s’est poursuivie tout au long du 2e millénaire av. J.-C. Ces données fournissent désormais une séquence robuste concernant l’évolution morphologique du mil, la première céréale indigène domestiquée en Afrique de l’Ouest.

In this paper, we detail the development and goals of a brand new turboshaft engine called BEARCAT. “BEARCAT” is an acronyme for ‘’Banc d’Essai Avancé pour la Recherche en Combustion et Aérothermique des Turbomachines’’. BEARCAT is based on a MAKILA engine, a turboshaft developed by Safran Helicopter Engines (formerly Turboméca) and powering the H215 (2 Makila 1A1, 1820 SHP each) and the H225 (2 Makila 2A1, 2000 SHP each) of Airbus Helicopters. BEARCAT is developed by SAFRAN-Tech, the Research and Technology Center of the SAFRAN Group. This test engine is devoted to the fine characterization of aero-thermal phenomena occurring within the combustion chamber and the High Pressure Turbine as well as their interactions. Therefore, BEARCAT differs from a standard test engine by the implementation of metrologies inside the combustion chamber and the 2-stage High Pressure Turbine, in order to perform both steady and non-steady flow measurements which will be used to validate CFD codes and models. The engine instrumentation induces thorough modifications of several engine parts and also the development of original technical solutions to ensure metrologies integration in minimizing their impact on performances.

This paper concerns the ceramic assemblages of two late second to early first millennia BC cemeteries, Oakaie 1 and Nyaung’gan, located in the Sagaing region of Upper Myanmar. In total, sixty-one graves have been excavated. Various grave goods were recovered in addition to the pottery, numerous classes of which exhibited stylistic similarities from one site to the other. Based on this observation, this article questions the existence of shared cultural traditions and interactions between the populations using the two cemeteries. A technological analysis of pottery was conducted, allowing us to classify pottery into socially significant techno-stylistic groups. For each site, the detailed analysis of techniques and styles permits the characterization of different groups of pottery which, examined in the light of the bioarchaeological and stratigraphic data, can be used to distinguish burial phases and to refine the chronology., Cet article propose de s’intéresser à deux cimetières estimés de la fin du deuxième au début du premier millénaire avant notre ère et situés dans la région de Sagaing en Haute Birmanie : Oakaie 1 et Nyaung’gan. Au total, soixante-et-une tombes ont été mises en évidence. Elles ont livré un riche matériel archéologique, dont du mobilier céramique qui présente des similitudes stylistiques d’un site à l’autre. Partant de ce constat, se sont alors posées les questions de l’existence ou non de traditions culturelles partagées et d’interactions entre les populations des deux cimetières. Grâce à une analyse technologique du matériel céramique, qui offre la possibilité de classer les poteries en groupes techno-stylistiques socialement significatifs, nous avons identifié plusieurs traditions. Pour chaque site, l’étude détaillée des variations techniques et stylistiques a permis de caractériser différents groupes de poteries qui, examinés à la lumière des données bioarchéologiques et de terrain, peuvent être utilisés pour distinguer des phases d’inhumation. Nous avons alors comparé la totalité des groupes céramiques afin d’évaluer les liens entre les deux sites et proposer des hypothèses permettant de questionner leur contemporanéité et d’affiner la chronologie., Favereau Aude, Pryce Thomas Oliver, Win Tin Tin, Champion Louis, Win Thu Thu, Myat Myat Htwe Kalayar, Mar Aye Aye, Pradier Baptiste, Willis Anna. Étude du mobilier céramique de deux cimetières de la fin du deuxième au début du premier millénaire avant notre ère en Haute Birmanie : technologie, typologie et chronologie. In: Bulletin de l'Ecole française d'Extrême-Orient. Tome 104, 2018. pp. 33-61.

Recent archaeobotanical analysis revealed that the botanical remains from the site of Tongo Maare Diabal (Mali) are composed primarily of pearl millet remains (up to 85%). Contemporaneous West African sites (500–1200 Cal AD) usually display more diverse patterns, especially by the end of this period. Indeed, contemporary urban sites of the West African Sahel often comprise combined and diversified farming systems of millet (Pennisetum glaucum), African rice (Oryza glaberrima), sorghum (Sorghum bicolor), Echinochloa sp. and fonio (Digitatia exilis). This article seeks to explain the near-exclusive focus of Tongo Maare Diabal’s agricultural economy on millet, particularly with regard to the site’s status as a settlement of iron workers.

Since the 1970s, the quest for finding the origins of domesticated sorghum in Africa has remained elusive despite the fact that sorghum (Sorghum bicolor (L.) Moench. sensu stricto) is one of the world’s most important cereals. Recognized as originating from wild populations in Africa (Sorghum arundinaceum (Desv.) Stapf), however, the date and cultural context of its domestication has been controversial, with many scholars inferring an early Holocene origin in parallel with better-known cereal domestications. This paper presents firm evidence that the process of domesticating sorghum was present in the far eastern Sahel in the southern Atbai at an archaeological site associated with the Butana Group. Ceramic sherds recovered from excavations undertaken by the Southern Methodist University Butana Project during the 1980s from the largest Butana Group site, KG23, near Kassala, eastern Sudan, were analyzed, and examination of the plant impressions in the pottery revealed diagnostic chaff in which both domesti...

Many societal and environmental changes occurred between the 2nd millennium BC and the middle of the 2nd millennium AD in western Africa. Key amongst these were changes in land use due to the spread and development of agricultural strategies, which may have had widespread consequences for the climate, hydrology, biodiversity, and ecosystem services of the region. Quantification of these land-use influences and potential feedbacks between human and natural systems is controversial, however, in part because the archaeological and historical record is highly fragmented in time and space. To improve our understanding of how humans contributed to the development of African landscapes, we developed an atlas of land-use practices in western Africa for nine time-windows over the period 1800 BC–AD 1500. The maps are based on a broad synthesis of archaeological, archaeobotanical, archaeozoological, historical, linguistic, genetic, and ethnographic data, and present land use in 12 basic categories. The main differences between categories is the relative reliance on, and variety of, domesticated plant and animal species utilized, and the energy invested in cultivating or keeping them. The maps highlight the irregular and frequently non-linear trajectory of land-use change in the prehistory of western Africa. Representing an original attempt to produce rigorous spatial synthesis from diverse sources, the atlas will be useful for a range of studies of human–environment interactions in the past, and highlight major spatial and temporal gaps in data that may guide future field studies., Open access funding provided by Max Planck Society. This work was supported by Grants to JOK from the European Research Council (COEVOLVE, 313797), the Swiss National Science Foundation (ACACIA, CR10I2_146314), and the Fondation Herbette (2016-2-E-16). JMR was funded by the Funds for Research Training in Industry and Agriculture (National Funds for Scientific Research, Belgium) and the Leopold II Funds (Belgium). Data were also acquired in the framework of the Era-Net BiodivERsA CoForChange project, funded by the French National Research Agency and National Environment Research Council (UK).

Archaeobotany’s goals are to investigate the interactions between human societies and the plant world in the past from the botanical remains preserved in archaeological sites, including the environment people exploited and the foods they extracted from it. Archaeobotanical research in Africa has tended to be less widely practiced than in many other parts of the world, and systematic archaeobotanical sampling is still only incorporated into a minority of archaeological field projects in Africa. Nevertheless, there is potential for archaeobotany to contribute to a holistic understanding of Africa’s past. The general scope of archaeobotany is outlined before focusing on how typical archaeobotanical remains relate to agriculture and food production. A short overview on the practical side of collecting archaeobotanical samples is provided. Archaeobotany’s two general themes are discussed: hunter-gatherer subsistence and the origins of agriculture.

MicroCT visualisations of organic inclusions within pottery sherds from Khashm el Girba 23 (KG23), Sudan, reveal domesticated sorghum (Sorghum bicolor subsp. bicolor) at c. 3700–2900 BCE. The percentage of non-shattering spikelet bases was c. 73% of identifiable visualizations, with c. 27% representing wild types. These analyses demonstrate the domestication of sorghum is significantly earlier than suggested by previous archaeological research. These results also demonstrate that microCT scanning is a major qualitative and quantitative advance on pre-existing methods for the investigation of crop remains in pottery sherds, which hitherto have been reliant on surface impressions; it is non-destructive, provides higher resolution 3D imaging of organic inclusions, and enables greater archaeobotanical recovery of inclusions within a sherd. MicroCT analysis of ceramics, mudbrick and other building materials has considerable potential for improving the chronologies and resolution for the domestication of other cereals in the past.

Late prehistoric archaeological research in Myanmar is in a phase of rapid expansion. Recent work by the Mission Archeologique Francaise au Myanmar aims to establish a reliable Neolithic to Iron Age culture-historical sequence, which can then be compared to surrounding regions of Southeast Asia. Excavations at Nyaung'gan and Oakaie in central Myanmar have provided 52 new AMS dates, which allow the creation of Myanmar's first reliable prehistoric radiometric chronology. They have also identified the Neolithic to Bronze Age transition in central Myanmar, which is of critical importance in understanding long-range interactions at the national, regional and inter-regional level. This research provides the first significant step towards placing late prehistoric Myanmar in its global context.

The Niger River is second only to the Nile in length in Africa, and is host to dense populations of agriculturalists that supported in historical times states such as the kingdoms of Songhay and Mali. This is also the region to which the origin of the Niger-Congo language family, including its Bantu offshoot is attributed. Despite this, archaeobotanical evidence for the development of agricultural systems based on both ancient West African crops, like Pennisetum glaucum (L.) R. Br., Vigna unguiculata (L.) Walp. and Oryza glaberrima Steud., and crops introduced to the Niger Basin, such as Sorghum bicolor (L.) Moench. and Gossypium L. sp. has remained limited. In particular the role of multiple crop systems, that included both the wet (rice) and the dry (millets), has not been directly documented archaeobotanically. The present paper presents new archaeobotanical results from 12 sites in Benin that suggest that the rise of larger populations and population centers, like the urban site of Birnin Lafiya, developed only once agriculture diversified beyond pearl millet cultivation to include multiple cereals, as wet rice. The 12 sites are split in four time periods. Flotation results indicate that sites of the first phase (first millennium BC) were dominated by pearl millet, but included sorghum and cowpea. However by the second period (300–900 AD), rice dominated samples, correlated with increasing urbanism, a pattern congruent with existing evidence from Mali. In addition, we report evidence that probable fonio (Digitaria cf. exilis (Kippist) Staph.) also appeared first in this era of diversification, calling into question previous inferences about the antiquity of these West African millets. The third phase, 900–1400 AD, is characterized by an increase of pearl millet and a decrease of African rice. During the last time period, 1400–1950 BC, we notice a disappearance of rice and a diminution of pearl millet and sorghum. Also, the utilizations of tree fruit such as baobab ( Adansonia digitata L.), oil palm (Elaeis guineensis Jacq.), and African olive (Canarium schweinfurthii Engl.) are in constant evolution since the second period. We conclude that agricultural diversification helped to promote urbanization and state formation in the Niger River basin, and that diversification included both use of wetter environments for rice and more marginal dry environments for millet and sorghum.

info:eu-repo/semantics/published

This paper presents an experimental set-up developed for the simulation of overheatings under load representative of One Engine Inoperative events which can be encountered during in-service operation of turboshaft engines. These experiments provide several breakthroughs over classical testing equipments for the non-isothermal testing conditions of single crystal Ni-based superalloys. It was shown a major effect of thermal transition rates on the material behavior which was explained by microstructural evolutions.

International audience; In the context of the “Crossroads of Empires” project led by Anne Haour, one strand of enquiry aims to understand the history of blacksmith groups and the development of iron production in Dendi country, in the northern Republic of Benin. Numerous remains of iron production have been discovered, showing a great variability in furnace design and waste assemblages. At least three smelting traditions can be distinguished. In this paper, we present the smelting site of Kompa Moussékoubou (10th/11th c. AD) which has been investigated by archaeological and archaeometric methods. Beyond the archaeometallurgical results, the excavation of a 1 x 2 m trench on a settlement mound nearby and survey work, which place the site within its wider context, are also discussed. In particular, we offer a detailed analysis of the ceramics recovered during test pitting and within one of the furnaces itself. This paper thus offers a rare opportunity to combine archaeometallurgical and ceramics data.; Dans le cadre du projet « Crossroads of Empires » dirigé par Anne Haour, un volet de paléométallurgie s’est donné pour but de comprendre l’histoire des forgerons et l’évolution de la sidérurgie dans le Dendi, au nord-Bénin. Un grand nombre de vestiges sidérurgiques a été découvert, montrant une grande variabilité dans la morphologie des fourneaux et des déchets. Au moins trois traditions sidérurgiques ont été distinguées. Dans cet article, nous présentons le site de réduction Kompa Moussékoubou (10ème/11ème siècle ap. notre ère) qui a fait l’objet d’opérations archéologiques et d’analyses archéométriques. De plus, la fouille d’un sondage de 1 x 2 m sur une butte d’habitat proche et le travail de prospection, qui per-mettent de placer le site dans un contexte plus large, sont également discutés. Cet article offre ainsi une occasion rare de combiner les données d’archéométallurgie avec l’analyse de la céramique

In order to deepen the knowledge of the interaction between modern lean burn combustors and high pressure turbines, a real scale annular three sector combustor simulator has been assembled at University of Florence, with the goal of investigating and characterizing the generated flow field. To generate hot streaks and simulate lean burn combustors behavior, the rig is equipped with axial swirlers, fed by main air flow that is heated up to 531 K, and liners with effusion cooling holes that are fed by air at ambient temperature. The three sector configuration is used to reproduce the periodicity on the central sector. Ducts of different lengths have been mounted on the swirlers to reduce the interaction of the mainstream with the coolant. Such configurations have been tested, using different measurement techniques, in order to highlight the differences in the resulting flow fields. The work presented in this paper shows the experimental campaign carried out to investigate the flow turbulence at combustor exit, in isothermal conditions, by means of hot wire anemometry. The goal has been achieved by investigating each test point twice, using an automatic traverse system equipped, in turn, with two split-fiber probes, that allow to measure the velocity components on two planes orthogonal to each other. A method for the time correlation of the signals obtained by the two different tests has been used. In order to analyse the turbulence decay towards the vanes location, such measurements have been performed on two different planes: one located in correspondence of the combustor exit and the further one placed downstream, in the virtual location of the vanes leading edges.

In order to deepen the knowledge of the interaction between modern lean burn combustors and high pressure turbines, a real scale annular three sector combustor simulator has been assembled at University of Florence, with the goal of investigating and characterizing the generated aerothermal field and the hot streaks transport between combustor exit and the high pressure vanes location. To generate hot streaks and simulate lean burn combustors behavior, the rig is equipped with axial swirlers, fed by main air flow that is heated up to 531 K, and liners with effusion cooling holes that are fed by air at ambient temperature. The three sector configuration is used to reproduce the periodicity on the central sector and to allow to perform measurements inside the chamber, through the lateral walls. Ducts of different length have been mounted on the swirlers, preserving the hot mainflow from the interaction with coolant. Such configurations, together with the one without ducts, have been tested, using different measurement techniques, in order to highlight the differences in the resulting flow fields. First of all, isothermal PIV measurements have been performed on the combustion chamber symmetry plane, to highlight the mixing phenomena between the mainflow and cooling flows. Then a detailed investigation of the mean aerothermal field at combustor exit has been carried out, for nominal operating conditions, by means of a five hole pressure probe provided with a thermocouple, installed on an automatic traverse system. With the aim of analyzing the hot streaks transport and the flow field modification towards the vanes location, such measurements have been performed on two different planes: one located in correspondence of the combustor exit and the further one placed downstream, in the virtual location of the vanes leading edges. Therefore, an experimental database, describing the evolution of the flow field in a combustor simulator with typical traits of modern lean burn chambers, for different injector geometries, has been set up.

International audience; Dans le cadre du projet « Crossroads of Empires » dirigé par Anne Haour, un volet de paléométallurgie s’est donné pour but de comprendre l’histoire des forgerons et l’évolution de la sidérurgie dans le Dendi, au nord-Bénin. Un grand nombre de vestiges sidérurgiques a été découvert, montrant une grande variabilité dans la morphologie des fourneaux et des déchets. Au moins trois traditions sidérurgiques ont été distinguées. Dans cet article, nous présentons le site de réduction Kompa Moussékoubou (10ème/11ème siècle ap. notre ère) qui a fait l’objet d’opérations archéologiques et d’analyses archéométriques. De plus, la fouille d’un sondage de 1 x 2 m sur une butte d’habitat proche et le travail de prospection, qui permettent de placer le site dans un contexte plus large, sont également discutés. Cette communication offre ainsi une occasion rare de combiner les données d’archéométallurgie avec l’analyse de la céramique.

International audience; à venir

To develop and apply a model to assess the economic value of a workplace influenza programme from the perspective of the employer.The model calculated the avoided costs of influenza, including treatment costs, lost productivity, lost worker added value and the cost of replacing workers. Subtracted from this benefit were the costs associated with a vaccination programme, including administrative costs, the time to give the vaccine, and lost productivity due to adverse reactions. The framework of the model can be applied to any company to estimate the cost-benefit of an influenza immunisation programme.The model developed was applied to 4030 workers in the core divisions of a Brazilian pharma-chemical company.The model determined a net benefit of $US121,441 [129,335 Brazilian reals ($Brz)], or $US35.45 ($Brz37.75) per vaccinated employee (1997 values). The cost-benefit ratio was 1:2.47. The calculations were subjected to a battery of 1-way and 2-way sensitivity analyses that determined that net benefit would be retained as long as the vaccine cost remained below $US45.40 ($Brz48.40) or the vaccine was at least 32.5% effective. Other alterations would retain a net benefit as well, including several combinations of incidence rate and vaccine effectiveness.The analysis suggests that providing an influenza vaccination programme can incur a substantial net benefit for an employer, although the size of the benefit will depend upon who normally absorbs the costs of treating influenza and compensating workers for lost work time due to illness, as well as the type of company in which the immunisation programme is applied.

Since 2014 the Mission Archéologique Française au Myanmar has been excavating a prehistoric cemetery, Oakaie 1, adjacent to the famous Nyaung’gan Bronze Age cemetery in Sagaing Division. Oakaie 1 (OAI1) was selected as a Nyaung’gan proxy in order to better understand the Neolithic-Bronze Age-Iron Age chronological transitions in upper-central Myanmar, for eventual regional-scale synthesis. An initial attempt to AMS 14C date 13 human femurs failed due to a lack of collagen but a subsequent effort using an apatite dating methodology on 5 femurs was successful. These preliminary data bracket part of the cemetery from the 9th to 6th c. BC with a 4th-3rd c. BC outlier. Typological and technological analogies between OAI1 and Nyaung’gan pottery grave goods likewise suggest an early 1st millennium BC date for the local Bronze Age.

The aim of this study is to determine the discharge coefficient of a multiperforated wall sample designed by AVIO, and more precisely to show the influence of each surrounding flow (inside holes, coolant and main flows). Results obtained are compared to correlations from literature. As previously observed, it is found that the discharge coefficient is strongly dependent on the Reynolds number relative to the hole flow (Reh ). The influence of the coolant flow has been proved. The comparison with classical correlations shows many differences: i) on the expected asymptotic value ii) on the rate of increase for the lowest values of Reh . This influence is not taken into account by classical correlations deduced from experiments carried out without crossflow. Based on our experiments, we determined a general expression of Cd. Experimental data are fitted with a function of type Cd = A(1−exp(−B.Reh )), where A and B are expressed as functions of the Reynolds number (Re2 ) of the coolant flow.Copyright © 2005 by ASME