Simultaneous optical diagnostic velocity and scalar field by molecular tagging technique Stratified Flames View project

International audienc

Folding model analysis of proton scattering from 18,20,22^{18,20,22}O nuclei

The elastic and inelastic proton scattering on $^{18,20,22}$O nuclei are studied in a folding model formalism of nucleon-nucleus optical potential and inelastic form factor. The DDM3Y effective interaction is used and the ground state densities are obtained in continuum Skyrme-HFB approach. A semi-microscopic approach of collective form factors is done to extract the deformation parameters from inelastic scattering analysis while the microscopic approach uses the continuum QRPA form factors. Implications of the values of the deformation parameters, neutron and proton transition moments for the nuclei are discussed. The p-analyzing powers on $^{18,20,22}$O nuclei are also predicted in the same framework.Comment: 8 pages, 5 figure

Folding model analysis of proton scattering from mirror nuclei 18^{18}Ne and 18^{18}O

The elastic and inelastic scattering of protons from mirror nuclei $^{18}$Ne and $^{18}$O are studied in a folding model approach. For comparison, two different effective interactions are folded with Hartree-Fock densities to obtain the nuclear interaction potentials. Both of them provide equivalent descriptions to the data and the deformation parameters extracted from inelastic scattering are reasonable. The density dependence parameters obtained from nuclear matter calculations and used for present analysis also provide a good estimate for the nuclear mean free path. The present formalism unifies radioactivity, nuclear matter and nuclear scattering.Comment: 12 pages including 5 figure

The Potential Contribution of Mass Treatment to the Control of Plasmodium falciparum Malaria

Mass treatment as a means to reducing P. falciparum malaria transmission was used during the first global malaria eradication campaign and is increasingly being considered for current control programmes. We used a previously developed mathematical transmission model to explore both the short and long-term impact of possible mass treatment strategies in different scenarios of endemic transmission. Mass treatment is predicted to provide a longer-term benefit in areas with lower malaria transmission, with reduced transmission levels for at least 2 years after mass treatment is ended in a scenario where the baseline slide-prevalence is 5%, compared to less than one year in a scenario with baseline slide-prevalence at 50%. However, repeated annual mass treatment at 80% coverage could achieve around 25% reduction in infectious bites in moderate-to-high transmission settings if sustained. Using vector control could reduce transmission to levels at which mass treatment has a longer-term impact. In a limited number of settings (which have isolated transmission in small populations of 1000–10,000 with low-to-medium levels of baseline transmission) we find that five closely spaced rounds of mass treatment combined with vector control could make at least temporary elimination a feasible goal. We also estimate the effects of using gametocytocidal treatments such as primaquine and of restricting treatment to parasite-positive individuals. In conclusion, mass treatment needs to be repeated or combined with other interventions for long-term impact in many endemic settings. The benefits of mass treatment need to be carefully weighed against the risks of increasing drug selection pressure

Premixed Turbulent Flames and Spectral Approach

International audienc

1-Arsa-3-germaallene tip(t-Bu)Ge=C=AsMes*: The heaviest mixed group 14 and 15 heteroallenic compound

cited By 8International audienceThe 1-arsa-3-germaallene Tip(t-Bu)Ge=C=AsMes* (1, Tip = 2,4,6-triisopropylphenyl, Mes* = 2,4,6-tri-tert-butylphenyl), a stable heavier group 14 and 15 congener of allenes, has been synthesized by debromofluorination of Tip(t-Bu)Ge(F)-C(Br)=AsMes. It reacts with methanol and 2,3-dimethyl-1,3-butadiene by the Ge=C double bond. The allenic-type structure of 1, featuring cumulated Ge=C and C=As double bonds, has been evidenced by means of spectroscopic and single-crystal X-ray determination. The electronic properties involved in this new system were obtained from DFT calculations. The mechanism of the reaction between 1 and the dimethylbutadiene is also described to understand the observed regio- and chemoselectivity. © 2011 American Chemical Society

Interaction entre une flamme et une paroi : rôle des transferts thermiques pariétaux

International audienc

Estimating the air shower XmaxX_{max} from radio measurements

International audienceIt is possible to use the radio signal emitted by air showers to estimate the primary cosmic ray characteristics, in particular its nature through the shower X max. The electric field emitted by air showers is computed assuming an atmospheric model; we need to know the air density and refractive index since these parameters have and influence on the development of the shower and the emitted electric field. We can get an unbiased estimation using the Global Data Assimilation System (GDAS) to compute the precise atmospheric conditions at the time and location an event is detected. We show how to use these data

Simultaneous optical diagnostic velocity and scalar field by molecular tagging technique Stratified Flames View project

International audienc

From the Observation of UHECR Radio Signal in [1-200] MHz to the Composition: CODALEMA and EXTASIS Status Report

International audienceOver the years, significant efforts have been devoted to the understanding of the radio emission of extensive air shower (EAS) in the range [20-80] MHz but, despite some studies led until the nineties, the [1-10] MHz band has remained unused for nearly 30 years. The EXTASIS experiment, located within the radio astronomy observatory of Nançay and supported by the CODALEMA instrument, aims to reinvestigate the [1-10] MHz band, and to study the so-called "Sudden Death" contribution, the expected radiation electric field created by the particles that are stopped upon arrival to the ground. We present the instrumental setup and the results obtained with EXTASIS.Moreover, CODALEMA has demonstrated that in [20-80] MHz, the commonly used band, the electric field profile of extensive air showers is well understood, and contains all the information needed for the reconstruction of extensive air showers. An analysis pipeline was developed to set up an online reconstruction of the primary cosmic ray properties. Combining the antenna and acquisition system capabilities, CODALEMA extended the observation window up to 200 MHz, permitting to improve the quality of the reconstruction of the primary cosmic ray properties thanks to a fine calibration procedure. We present the results obtained on a large batch of cosmic ray events, notably a first estimate of their mass dependence with energy