THz Magneto-electric atomic rotations in the chiral compound Ba3_3NbFe3_3Si2_2O14_{14}

We have determined the terahertz spectrum of the chiral langasite Ba$_3$NbFe$_3$Si$_2$O$_{14}$ by means of synchrotron-radiation measurements. Two excitations are revealed that are shown to have a different nature. The first one, purely magnetic, is observed at low temperature in the magnetically ordered phase and is assigned to a magnon. The second one persits far into the paramagnetic phase and exhibits both an electric and a magnetic activity at slightly different energies. This magnetoelectric excitation is interpreted in terms of atomic rotations and requires a helical electric polarization

Nuclear risk, from Radioisotope (bio)chemistry to Public Perception

International audienc

Une approche de la perception publique de l'énergie nucléaire

International audienc

Nuclear risk, from Radioisotope (bio)chemistry to Public Perception

International audienc

Une approche de la perception publique de l'énergie nucléaire

International audienc

Investigation on the vibrational and structural properties of a self-structured bridged silsesquioxane

International audienceThe crystalline structure of ureidopyrimidinone-based silane (UPY) has been determined. The local and long range order structuring of the bridged silsesquioxane (MUPY) resulting from the sol-gel hydrolysis-condensation of the former precursor has been investigated by MFTIR (Mid Fourier Transform InfraRed) combined with DFT (Density Functional Theory) and XRD (X-ray diffraction) studies. These studies showed that a long range structuring exists within the organic fragments with the transcription of the DDAA (Donor-Donor-Acceptor-Acceptor) H-bonding array from UPY to MUPY whereas a disordered siloxane network was revealed in the hybrid material

Comparative analysis of the perception of nuclear risk among two populations (expert/non-expert) in France

As part of the UCA JEDI IDEX program, the NR2P2* project brought together a multidisciplinary team to interview 2315 people via an online survey to assess their perception of nuclear risk via 33 questionsInternational audienceIn the context of ecological change and the fight to reduce CO2 emissions, nuclear energy can appear to be an efficient energy source, or at least essential from the perspective of energy diversification. However, it suffers from a poor image and a lack of knowledge among the population, and among young people in particular, who favor the development of renewable energy. We wanted to know exactly what was happening in one of the most nuclearized countries in the world, France. To do this, we interviewed a young, student, "non-expert" population about their knowledge and perceptions of nuclear risk and compared the results with a so-called "expert" population: firefighters, most of whom had received training in radiation protection. Thus, in response to the question "Are you afraid of the nuclear sector?" 68% of students answered yes compared to 49% of firefighters. The reasons for fear are sometimes similar (radioactive waste, contamination over long periods, ageing of power plants), and sometimes divergent due to the better knowledge of the firefighters who had undergone radiological training (out of control, fear of the effects of radioactivity). Science students differed from other students by being more in favor of a partial exit from nuclear power (50%, compared to 12% for students from other disciplines), and by indicating that they were more open than others to the possibility of changing their minds if they had more knowledge on the subject (43%). In terms of behavior, the gaps are, as expected, wide between the 2 populations (students/firefighters): less than half (44%) of students adopt the right reflexes (seeking a confined space, sealing ventilation), 55% would prepare for an evacuation and 84% would keep themselves informed, not through social networks as we might think, but through a state organization in charge of managing the nuclear sector. If an alert were to occur, students report that they would be anxious (42%), frightened (12%) or even panicked (25%), unlike firefighters who would of course behave as expected, be more reasoned, and much less panicked (difference of 21%), although half of them admit that they would still be anxious. The results reveal differentiated profiles between the 2 populations (expert/non-expert) in terms of the association between exposure to radioactivity and the occurrence of cancers, and in the level of confidence in nuclear energy in France