17 research outputs found
Revisiting Kalundu Mound, Zambia: implications for the timing of social and subsistence transitions in Iron Age Southern Africa
Novel trajectories of food production, urbanism, and inter-regional trade fueled the emergence of numerous complex Iron Age polities in central and southern Africa. Renewed research and re-dating efforts in Botswana, Zimbabwe, and along the Swahili Coast are transforming models for how inter-regional interaction spheres contributed to these patterns. While societies in present-day Zambia played an important role in the trade of copper, ivory, gold, and other resources between central and southern Africa, little is known about lifeways during the rise of social complexity in this region. This paper reports the results of re-excavation at Kalundu Mound on the Batoka Plateau of southern Zambia, one of the iconic mound sites of the Iron Age “Kalomo Culture.” New radiocarbon dates were combined with the original dates in a series of Bayesian models, indicating that previous chronologies for the site are not reliable and that the mound site likely developed rapidly from AD 1190 to 1410. Archaeobotanical, zooarchaeological, and paleo-proteomic analyses of excavated materials suggests a broad subsistence base combining wild and domesticated species, including the first reported evidence for finger millet (Eleusine coracana) in the region. Considering these findings, it is necessary to re-evaluate the temporal context of the Kalomo site-group, and to also systematically reinvestigate the systems of exchange and subsistence that supported Later Iron Age complexity.Introduction Situating Kalundu Mound Within the Regional Archaeology Kalundu Mound and the Kalomo Culture - Environmental Setting and Regional History - The 1957 Excavations - The 1960–1962 Excavations - The 2017 Excavations Results - Stratigraphy - Chronology - Chronological Modeling Results - Chronology Summary Subsistence - Faunal Remains - Macrobotanical Remains - Material culture Discussion - Site Formation - Iron Age Agriculture at Kalundu - Chronology for Kalundu Mound and the Kalomo Group Conclusio
Revisiting Kalundu Mound, Zambia: Implications for the Timing of Social and Subsistence Transitions in Iron Age Southern Africa
Novel trajectories of food production, urbanism, and inter-regional trade fueled the emergence of numerous complex Iron Age polities in central and southern Africa. Renewed research and re-dating efforts in Botswana, Zimbabwe, and along the Swahili Coast are transforming models for how inter-regional interaction spheres contributed to these patterns. While societies in present-day Zambia played an important role in the trade of copper, ivory, gold, and other resources between central and southern Africa, little is known about lifeways during the rise of social complexity in this region. This paper reports the results of re-excavation at Kalundu Mound on the Batoka Plateau of southern Zambia, one of the iconic mound sites of the Iron Age “Kalomo Culture.” New radiocarbon dates were combined with the original dates in a series of Bayesian models, indicating that previous chronologies for the site are not reliable and that the mound site likely developed rapidly from AD 1190 to 1410. Archaeobotanical, zooarchaeological, and paleo-proteomic analyses of excavated materials suggests a broad subsistence base combining wild and domesticated species, including the first reported evidence for finger millet (Eleusine coracana) in the region. Considering these findings, it is necessary to re-evaluate the temporal context of the Kalomo site-group, and to also systematically reinvestigate the systems of exchange and subsistence that supported Later Iron Age complexity
Effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to post-harvest proliferation of Salmonella enterica
Fresh fruits and vegetables are increasingly recognized as vehicles of salmonellosis. Pre- and post-harvest environmental conditions, and physiological, and genetic factors are thought to contribute to the ability of human pathogens to persist in the production environment, attach to, colonize and proliferate in and on raw produce. How field production conditions affect the post-harvest food safety outcomes is not entirely understood. This study tested how varying nitrogen and potassium fertilization levels affected the "susceptibility" of tomatoes to Salmonella infections following the harvest of fruits. Two tomato varieties grown over three seasons under high, medium, and low levels of nitrogen and potassium fertilization in two locations were inoculated with seven strains of Salmonella. Even though the main effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to infections with Salmonella enterica were not statistically significant overall, differences in nitrogen concentrations in plant tissues correlated with the susceptibility of partially ripe tomatoes (cv. Solar Fire) to Salmonella. Tomato maturity and the season in which tomatoes were produced had the strongest effect on the ability of Salmonella to multiply in tomatoes. Tomato phenolics, accumulation of which is known to correlate with rates of the N fertilization, did not inhibit growth of Salmonella in vitro
Vibration And Acoustics In Porous Insulating Materials - The Help Of Fe Numerical Simulations For The Analysis Of Experiments In Rooms And Tubes
To illustrate our purpose we first recall the results of a 4 years study, carried out at the ISMEP, of trimmed fuselage panels of aircraft and multilayered insulating systems. We underline the complementarities of real tests in transmissibility rooms with a set of FE and analytical methods we have developed. Two major difficulties exist i) high performance panel tests rapidly reach the limit of the experimental device, ii) short wave length in poroelastic material do not allow us direct 3D finite element calculations in all the frequency band [0 ; 6,000 Hz] of interest. Therefore, 3D models are completed with 2D models and an analytical method. We show that all this numerical tools are needed to understand the tests and to investigate some particular points as the mounting of the panel in the acoustic room. An other problematic question with poro-elastic materials is that the characterization of the material itself, which is of prior importance for inputting data in numerical models, is highly difficult to carry out. This second point motivates present research at UNICAMP based on the use of FE numerical calculations to determine the absorption and the transmissibility of porous samples in tubes. The construction of modified tubes are also envisaged for a better control of the boundary conditions during tests while the FE model will allow us to recover some fundamental characteristics by inverse calculation. We learned from our first simulations that high precisions calculations are needed to substitute the real device with a numerical one. We list at the end of the paper, new research involving virtual and real tests: curved panels, active control, noise inside a simplified aircraft cabin. From sub-structures to samples of materials, FE calculation proves itself of most practical benefits to exploit tests involving porous materials.429032912Tanneau, O., (2004) Modélisation de Panneaux d'Isolation Aéronautique - Couplages Poro-élastiques, Élastodynamiques et Acoustiques Par Méthodes Analytiques, FEM et BEM, , PhD thesis, University of Pierre et Marie Curie, Paris VILamary, P., Aircraft friendly cabin environment -Enhancement acoustic and vibro-acoustic numerical methods for trimmed fuselage models Proceedings of the XI DINAME, 28th February-4th March, 2005 - Ouro Preto, Brazil, 2005Lamary, P., Casimir, J.-B., Tanneau, O., Pompéi, M., Noise control inside aircraft - Virtual transmissibility tests using CAVOK FE solver Proceedings EuroNoise, Naples 2003Dauchez, N., (1999) Etude Vibro-acoutic des Matériaux Poreux Par Élé ments Finis, , PhD thesis, University of Le Mans, University of SherbrookeSong, B.H., Bolton, J.S., Investigation of the vibration modes of edge-constrained fibrous samples placed in a standing wave tube (2003) JASA, (113), p. 1833Valetim Donadon, L., Lamary, P., Camino, J., De França Arruda, J.R., Application of Active Sound Intensity Control of Sound Transmitted through Panels 12th ICSV Congress, Lisbon 2005Lamary, P., (2005) Final Report of Activity, FAPESP Processo 2003/09812
Simulation of primary atomization with an octree adaptive mesh refinement and VOF method
International audienceWe present different simulations of primary atomization using an adaptive Volumeof-Fluid method based on octree meshes. The use of accurate numerical schemesfor mesh adaptation, Volume-of-Fluid advection and balanced force surface tensioncalculation implemented in Gerris, the code used to perform the simulationsincluded in this work, has made possible to carry out accurate simulations withcharacteristic scales spreading over several orders of magnitude. The code isvalidated by comparisons with the temporal linear theory for moderate densityand viscosity ratios, which basically corresponds to atomization processes inhigh pressure chambers. In order to show the potential of the code in differentscenarios related to atomization, preliminary results are shown in relation withthe study of the two-dimensional and 3D temporal and spatial problem, theinfluence of the injector and the vortex generated inside the chamber, and theeffect of swirling at high Reynolds numbers