[en] A series of experiments are reported to investigate the behaviour of DDT in seawater using ³⁶Cl-DDT to determine DDT solubility in seawater, its adsorption to walls of glass vessels, the reproductibility of DDT extraction from seawater by organic solvents and its volatility when brought to dryness from solution

[en] The climatic risks are analyzed in this book under the cross-vision of specialists of different domains: philosophy, sociology, economic history, law, geography, climatology and hydrology. The prevention of risks and the precautionary principle are presented first. Then, the relations between climatic risk and geography are analyzed using the notion of territoriality. The territory aspect is in the core of the present day debates about the geography of risks, in particular when the links between climate change and public health are considered. Then the main climatic risks are presented. Droughts and floods are the most damaging ones and the difficulties of prevention-indemnification coupling remain important. (J.S.)

[en] The onset of laser beam filamentation in a preformed nonuniform plasma is investigated by using a two-dimensional computer code in which time-dependent plasma hydrodynamics and heat transport effects are accounted for. Laser beam propagation is modeled using a paraxial wave approximation: refraction, diffraction, absorption, and ponderomotive force effects are accounted for. The simulations reveal details by which multifilamentary plasma and laser beam structures evolve in the region near the critical density surface. For the particular case of a 1.05 μm laser beam with an intensity of 10/sup 15/ W/cm² incident on a long scale length preformed plasma, a consistent treatment of the ponderomotive forces and of the plasma dynamics is found to be essential in determining the evolution of the filamentary structures

[en] Analytic expressions are derived for the integrals with singularities in the Feynman parametrization. (author)

[en] In recent years IBA has continued its development of state-of-the-art systems for Proton Therapy. While the machine performance at the NPTC is such that all clinical specifications are met, IBA has continued to improve the proposed equipment to set even higher standards. Improvements in the ion source control, gantries, and patient alignment systems will be addressed in the oral presentation and the first results obtained with the Pencil Beam Scanning algorithm will be presented

[en] The 1D spin transition compound [Fe(L1)₃](ClO₄)₂ (1) with L1 ethyl-4H-1,2,4-triazol-4-yl-acetate, a novel neutral bidentate ligand, has been synthesised. The temperature dependence of the high-spin molar fraction derived from ⁵⁷Fe Mossbauer spectroscopy reveals an exceptionally abrupt single step transition between low-spin and high-spin states with a hysteresis loop of width 5 K (T_c^u = 298 K and T_c^↓ = 293 K). This spin transition operating around room temperature presents striking reversible thermochromism from white at 295 K to pink at ice temperature, behaving as an optical alert towards temperature variations. This first order phase transition was additionally followed by differential scanning calorimetry in good agreement with Moessbauer spectroscopy data. The spin transition properties of a freshly prepared sample of 1, dried under a N₂(g) stream which was formulated as [Fe(L1)₃](ClO₄)₂·MeOH (2), are shifted below room temperature (T_1/2^u = 273 K and T_1/2^↓ 263 K), thus showing a remarkable influence of solvent inclusion on the spin state of these chain compounds.

[en] The aim of this work was to evaluate ¹²³I-ILIS as a radioligand of dopamine receptors in patients with extra-pyramidal diseases by using different cameras in two different centers. 45 patients were included and divided in 2 groups: group I (n=28): idiopathic Parkinson disease, group II (n=17): other extra-pyramidal syndrome. ¹²³I-ILIS, 1.7 to 2.8 MBq/kg, was injected after informed consent. Imaging was performed with a single head camera, a dual head camera, a triple head camera and a brain dedicated annular detector. The pattern of the transverse slices containing the basal ganglia was classified according to 3 types: type 1: visible basal ganglia and invisible cortex, type 2: invisible basal ganglia and visible cortex, type 3: visible basal ganglia and cortex. Striatal/frontal cortex ratio (S/FC) was calculated from standardized, geometrical ROI's. No patient showed any undesirable effect. All SPECT images were interpretable. In group 1, 45/45 scintigraphic pattern were type 1 or 3, in group II 18/23 scintigraphic patterns were type 2 or 3. S/FC was significantly lower in group II than in group I patients. We conclude that ¹²³I-ILIS SPECT can be performed with any conventional γ-camera. It provides functional informations about the striatal dopaminergic synapse in patients with extra-pyramidal degenerative disease, and could be useful in the differential diagnosis between Parkinson disease and other extra-pyramidal syndromes. (author)

[en] The G⁰ parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross section was measured for (rvec e)p elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required on the asymmetry, the G⁰ experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events at a mean rate of 2 MHz per detector with low deadtime and to minimize helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G⁰ forward-angle measurements

[en] The GUINEVERE project is an international project in the framework of IP-EUROTRANS, the FP6 program which aims at addressing the main issues for ADS development in the framework of partitioning and transmutation for nuclear waste volume and radiotoxicity reduction. The GUINEVERE project is carried out in the context of domain 2 of IP-EUROTRANS, ECATS, devoted to specific experiments for the coupling of an accelerator, a target and a subcritical core. These experiments should provide an answer to the questions of online reactivity monitoring, sub-criticality determination and operational procedures (loading, start-up, shutdown,...) in an ADS by 2009-2010. The project has the objective to couple a fast lead core, within the VENUS building operated by the SCK.CEN, with a neutron generator able to work in three different modes: pulsed, continuous and continuous with beam interruptions at the millisecond scale. In order to achieve this goal, the VENUS facility has to be adapted and a modified GENEPI-3C accelerator has to be designed and constructed. The paper describes the main modifications to the reactor core and facility and to the accelerator, which will be executed during the years 2008 and 2009, and the experimental programme which will start in 2009. (authors)

[en] We propose to study nucleon structure by Virtual Compton Scattering using the reaction p(e,e'p)γ with the MAMI facility. We will detect the scattered electron and the recoil proton in coincidence in the high resolution spectrometers of the hall A1. Compton events will be separated from the other channels (principally π⁰ production) by missing-mass reconstruction. We plan to investigate this reaction near threshold. Our goal is to measure new electromagnetic observables which generalize the usual magnetic and electric polarizabilities. (authors). 9 refs., 18 figs., 7 tabs