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Africa is poised for a revolution in the quality and relevance of weather predictions, with potential for great benefits in terms of human and economic security. This revolution will be driven by recent international progress in nowcasting, numerical weather prediction, theoretical tropical dynamics and forecast communication, but will depend on suitable scientific investment being made. The commercial sector has recognized this opportunity and new forecast products are being made available to African stakeholders. At this time, it is vital that robust scientific methods are used to develop and evaluate the new generation of forecasts. The GCRF African SWIFT project represents an international effort to advance scientific solutions across the fields of nowcasting, synoptic and short-range severe weather prediction, subseasonal-to-seasonal (S2S) prediction, user engagement and forecast evaluation. This paper describes the opportunities facing African meteorology and the ways in which SWIFT is meeting those opportunities and identifying priority next steps. Delivery and maintenance of weather forecasting systems exploiting these new solutions requires a trained body of scientists with skills in research and training; modelling and operational prediction; communications and leadership. By supporting partnerships between academia and operational agencies in four African partner countries, the SWIFT project is helping to build capacity and capability in African forecasting science. A highlight of SWIFT is the coordination of three weather-forecasting ?Testbeds? ? the first of their kind in Africa ? which have been used to bring new evaluation tools, research insights, user perspectives and communications pathways into a semi-operational forecasting environment.

International audience; This paper presents the results of the latest version of TRIPOLI-4 [1] on its criticality validation suite, part I dedicated to thermal spectra. The criticality validation suite is made of 148 carefully chosen ICSBEP [2] benchmarks with various enrichments, fissile materials and spectra. The ICSBEP benchmarks computational models are prepared by the TRIPOLI-4 VetV team and are run in the same conditions for each benchmark initial source, number of neutrons per cycle, number of inactive and active cycles, keff estimator, nuclear data. Comparisons are made with the measured keff as well as with previous versions of TRIPOLI-4.

Currently only thirteen percent (13 %) of domestic wastewater produced daily in Dakar is being treated. Industrial and agricultural activities and domestic waste are the source of significant pollution of the marine and coastal environment in Senegal. Our work focuses on assessing the overall toxicity of sediments, the microbiological and chemical quality of water, and the quantification of microplastics around the Cape Verde Peninsula. Physicochemical measurements are carried out in situ and the sampling points correspond to effluent outlets, compared to two reference stations that are assumed to have little or no contamination. A total of 15 sites were collected: Cambéréne, Yoff Tonghor, Ngor, Almadie-Vivier, Ouakam, Magdalen Islands, Soumbédioune, Dakar Dantec, Hann1, Hann2, Port of Dakar, Lac rose, Guédiawaye, Mamelles and UCAD. High sediment toxicity [100% ADL (Larval Development Anomalies)] was demonstrated at sixty percent (60%) of the sites. Twenty percent (20%) of sites have intermediate toxicity ranging from 30% to 60% ADL). Sites with the lowest toxicity (up to 30% ADL) accounted for only 20% and no ADL values were reported as nil. Mercury levels in sediments are very low, with a notable variation between sites in the north and those in the south of the peninsula. Coliforms (Escherichia coli) and enterococci are present in large quantities at most sites (64%). The presence of Salmonella is noted only in Cambéréne. The results of mass spectrometry analyzes also show overall high concentrations of heavy metals (Al, Cd, Cr, Co, Cu, Hg, Ni and Zn) with the exception of Fe and Mn, which are below the criteria for "Protection of acute and chronic aquatic life". Microplastic analysis revealed high mean values: 25,864 mpts / km2 (42 g / km2) for microplastics (300 µm and 5 mm) and 37,441 MPTS / km2 (97.33 g / km2) for macroplastics > 5 mm and < 200 mm). All the results obtained show, according to the pollutants, the importance of the sediment granulometry, the nature of the pollution, the size of the effluents, the anthropic contributions, the atmospheric falls like that of the behaviors of the populations. Our results are discussed with a view to environmental monitoring at the local, regional or national level. They will also allow this approach to be extended to other contaminants (hydrocarbons, metals, pesticides, megaplastics) as well as bio-trials in the various compartments of the marine and coastal environment (sediments, waters, fauna and flora ). An in-depth statistical analysis will also allow optimization of ecotoxicological monitoring, sampling and analysis strategies.

Let $E$ be a Banach space either $l_p$ or $L_p$ or $W^{m,p}$, $1 < p < \infty$, with dual $E^*$, and let $F :E\mapsto E^*$, $K: E^*\mapsto E $ be Lipschitz and strongly monotone mappings with $D(K)=R(F)=E^*$. Assume that the Hammerstein equation $u+KFu=0$ has a unique solution $\bar u$. For given $u_1\in E$ and $v_1\in E^*$, let $\{u_n\}$ and $\{v_n\}$ be sequences generated iteratively by: $u_{n+1} = J^{-1}(Ju_n -\lambda(Fu_n-v_n)),\,\,\,n\geq 1$ and $v_{n+1} = J(J^{-1}v_n-\lambda(Kv_n+u_n)),\,\,\,n\geq 1$, where $J$ is the duality mapping from $E$ into $E^*$ and $\lambda$ is a positive real number in $(0,1)$ satisfying suitable conditions. Then it is proved that the sequence $\{u_n\}$ converges strongly to $\bar u$, the sequence $\{v_n\}$ converges strongly to $\bar v$, with $\bar{v}= F\bar{u}.$ Furthermore, our technique of proof is of independent interest.

Radiation shielding analysis conducted in support of design development of the contemporary diagnostic systems integrated inside the ITER ports is relied on the use of CAD models. This paper presents the CAD-based MCNP Monte Carlo radiation transport and activation analyses for the Diagnostic Upper and Equatorial Port Plugs (UPP #3 and EPP #8, #17). The creation process of the complicated 3D MCNP models of the diagnostics systems was substantially accelerated by application of the CAD-to-MCNP converter programs MCAM and McCad. High performance computing resources of the Helios supercomputer allowed to speed-up the MCNP parallel transport calculations with the MPI/OpenMP interface. The found shielding solutions could be universal, reducing ports R&D costs. The shield block behind the Tritium and Deposit Monitor (TDM) optical box was added to study its influence on Shut-Down Dose Rate (SDDR) in Port Interspace (PI) of EPP#17. Influence of neutron streaming along the Lost Alpha Monitor (LAM) on the neutron energy spectra calculated in the Tangential Neutron Spectrometer (TNS) of EPP#8. For the UPP#3 with Charge eXchange Recombination Spectroscopy (CXRS-core), an excessive neutron streaming along the CXRS shutter, which should be prevented in further design iteration.

International audience; A leakage model based on B1 Homogeneous Equations has been recently implemented in continuous-energy Monte Carlo code TRIPOLI4. This leakage model algorithm iterates between the point-wise Monte Carlo simulation and a B1 Homogeneous Equations solver till reaching a final critical state in Monte Carlo simulation. The two advantages of our leakage model compared with the others are: we use critical flux spectrum to generate the multi-group constants for solving the B1 Homogeneous Equations; the leakage coefficients calculated are considered in point-wise Monte Carlo simulation. This leakage model is validated by a pre-designed numerical experiment simulated with continuous-energy TRIPOLI4 and the obtained results are also compared with those from SERPENT leakage model and deterministic leakage model in ECCO code. Finally, our leakage-corrected multi-group constants are used in transport theory based core calculation and they give out consistent multiplicative factor and neutronic balance.

International audience

ll volume presenta la condizione postcoloniale come uno dei fattori determinanti che danno forma alla vita quotidiana e alla cultura dell'Italia contemporanea. Esso identifica un'ampia varietà di discorsi, pratiche sociali e forme di produzione culturale specificatamente postcoloniali che trovano espressione nell'Italia di oggi. Questo volume collettaneo non si limita a una rilettura del passato coloniale ma sottolinea come le relazioni di potere poste in essere dal colonialismo siano perpetuate e corroborate nella società attuale. Esso stabilisce inoltre un rapporto di continuità tra il passato coloniale e altri fenomeni centrali per la formazione dell'identità italiana, quali le emigrazioni transoceaniche ed europee, la subalternità del Sud, le migrazioni interne, il rapporto con il Mediterraneo e l'immigrazione contemporanea. Attraverso l'analisi di studiosi e studiose che operano in un contesto internazionale e interdisciplinare, il volume introduce a pieno titolo gli studi postcoloniali come campo di indagine che ampia e arricchisce il dibattito teorico-critico sulla storia e la cultura italiane.

International audience

Quatre variétés d'Hibiscus sabdariffa dont 3 d'origine sénégalaise et une provenant du Guatemala ont été dans un premier temps caractérisés de manière plus ou moins complète sur le plan physico-chimique, biochimique et nutritionnel. En second lieu la dégradation thermique de leurs anthocyanes dans des solutions aqueuses a été étudiée entre 30 et 100 °C. Pour les variétés sénégalaises la concentration en oxygène est constante (2,5 mg.L-1) tandis que pour la variété guatémaltèque la concentration d'oxygène est comprise entre 0,4 et 8,5 mg.L-1. L'ensemble des paramètres (k, k?, t1/2, D?, D0, Ea, z) cinétiques de la dégradation des anthocyanes ont été déterminés. Les quatre variétés présentent des teneurs en anthocyanes et en polyphénols totaux très importantes comprises entre 700 et 1200 mg/100g pour les anthocyanes et entre 800 et 1300 mg/100g pour les polyphénols totaux. La variété sénégalaise Vimto présente les teneurs les plus élevées en anthocyanes et polyphénols totaux. Les calices d'Hibiscus sabdariffa présentent également des teneurs moyennes en vitamine C et sucres (saccharose, glucose, fructose) respectivement de l'ordre de 55 mg/100g et 2 mg/100 g. Les variétés présentent des teneurs en minéraux plus ou moins différentes selon les variétés. Les teneurs en acides aminés sont de 5,45 et 4,55 g/100 g de matière sèche respectivement pour les variétés THAI et CLT 92 d'origine sénégalaise. L'analyse des données cinétiques révèle que la dégradation thermique des anthocyanes d'Hibiscus sabdariffa obéit à une relation d'ordre un. Pour les variétés sénégalaises l'énergie d'activation (Ea) est comprise entre 69,4 et 47,2 kJ.mol-1 avec des valeurs de z comprise entre 30 et 45 °C. D0 est comprise entre 2.107 et 4.106. Pour la variété provenant du Guatemala, les valeurs de k sont comprises entre 9,8 10-6 et 1,1.10-4 s-1. La température semble avoir un effet plus important sur la dégradation que la teneur en oxygène.

International audience