[en] Apparatus and method for directing a controlled number of laser pulses onto a work piece to be machined. More specifically, the laser machining apparatus includes an excitable laser and an excitation lamp for continuously exciting the laser to emit a sequence of laser pulses. The application of the laser pulses to the work piece is controlled by an inner-cavity shutter that is opened to permit a precise number of pulses to be directed onto the work piece. The frequency (REP RATE) and pulse width of the laser pulses are controlled by the excitation lamp and, in turn, are set to create a progressive weld of significant depth and structural integrity. In particular there is provided control means for counting the number of laser pulses applied to a machining site of the work piece, whereby a known controllable quantity of energy is imparted to each site. To this end, the counting of the laser pulses begins after the completion of a laser pulse, whereby the actuation of the inner-cavity shutter is not synchronized to the computer but rather to the laser emission so that only whole laser pulses will be applied to the site

[en] The aim of this paper is to compare the image quality of different CT units at four centres using first the same dose per slice, and then the dose per slice used when performing a standard abdominal acquisition. The results show that the detection of a 7 to 9 mm supra-slice object (i.e. larger than the slice thickness) of 0.5% can be obtained at a comparable dose level. The main difference between the performances of the CT appears when trying to detect a contrast level of 0.3%. When comparing the CT using the clinical acquisition parameters chosen, the same conclusions can be drawn in spite of the fact that the CTDI values varied by 65%. The most important result is the comparison of the effective dose which shows differences up to almost 100% between the centres involved. This paper confirms that the DLP concept is a powerful tool for the optimisation of CT examination protocols. (author)

[en] Thesis presentations have been organised in sessions which respectively addressed issues related to radiation safety, and to environment and health (urban atmosphere, dry deposition of aerosols, therapeutic benefit of an injection of mesenchymal stem cells, colorectal lesions, role of toll-like receptors (or TLR) in immune orientations induced by an abdominal irradiation. Plenary sessions also addressed these issues. Then sessions addressed issues related to parallel effects in low doses, to the parallel modelling of materials, to containment and aerosols, to neutron spectrometry and dosimetry. Some parallel sessions addressed issues related to geosphere, to severe accidents and fires. A plenary session addressed the Fukushima accident, the related R and D, and future investment. Poster sessions addressed several topics: safety (fire, containment, neutronics, civil engineering, methods), and radiation protection (radionuclide metrology, toxicology, radio-biology, dosimetry).