No abstract available

No abstract available

[en] The author describes a series of experiments on the irradiation of fresh white (lean) fish of the species Merluccius merluccius, in which the dose applied ranged between 50 and 300 krad and the irradiation conditions, i.e. packaging in different materials, temperature and atmosphere, were varied. The microbiological studies were concentrated on the evolution of residual microbial flora as a function of the parameters considered. The results obtained are discussed with a view to evaluating their significance from the commercial and health standpoints. It is concluded that under suitable conditions, with storage temperatures from 0 to 3°C and low initial contamination levels, it is possible to secure a commercially worthwhile prolongation of the storage life of hake fillets amounting to 10 to 12 days, by the application of doses of 50 and 100 krad. Larger doses are required for higher initial contamination indices-and also whenever gas-permeable wrapping materials are used. It will be necessary, however, to make, further tests to confirm the conclusions, and in so doing to broaden and improve various aspects and areas of the scheduled research. (author)

[en] We present in this work an analytical expression for permeability in a two-layer composite membrane, which was derived assuming the same hypothesis as those of Adzumi model for permeability in a homogeneous membrane. Whereas in Adzumi model permeability shows a linear dependence on the mean pressure, our model for a composite membrane related permeability to pressure through a rather complex expression, which covers the whole range of flow, from molecular-Knudsen to viscous-Poiseuille regimes. The expression obtained for permeability contained information of membrane structural properties as pore size, porosity and thickness of each layer, as well as gas nature and operational conditions. Our two-layer-model expression turns into Adzumi formula when the structure of the layers approach to each other.

[en] In this report the results of the experimental work carried out within the collaboration project between ITU-ENRESA-UPC/CTM on spent fuel (SF) covering the period 2005-2007 were presented. Studies on both RN release (Fast Release Fraction and matrix dissolution rate) and secondary phase formation were carried out by static and flow through experiments. Experiments were focussed on the study of the effect of BU with two PWR SF irradiated in commercial reactors with mean burn-ups of 48 and 60 MWd/KgU and; the effect of High Burn-up Structure (HBS) using powdered samples prepared from different radial positions. Additionally, two synthetic leaching solutions, bicarbonate and granitic bentonite ground wa ter were used. Higher releases were determined for RN from SF samples prepared from the center in comparison with the fuel from the periphery. However, within the studied range, no BU effect was observed. After one year of contact time, secondary phases were observed in batch experiments, covering the SF surface. Part of the work was performed for the Project NF-PRO of the European Commission 6th Framework Programme under contract no 2389. (Author)

[en] The workers of an area located under an hospital X Ray Service feel some alarm, because the perception of an excessive number of breast Ca. appeared in a few years. An investigation is promoted co-ordinated by the Medical Director and with the (among others) Labour Risk Prevention and Radiation Protection services participation. A first dosimetric report is given by the Radiation Protection Service (RPS) on the basis of years before (but not recent) measures, indicating that the values are in the random of non exposed dosemeter statistics. The Labour Risk Prevention Service (LRPS) investigates the rest of environmental agents and clinical factors. Obviously an actual and conclusive Report is needed, as soon as possible, to all levels, because the workers demand to close the area, under the leadership of the last woman affected partner, expert in building construction and worry about lead without, thinking too much in the ceiling structure. Elaborating a Report in that circumstances is, on the feeling of the experts responsible a matter of accuracy but, in the particular social context, to be quickly may be prevalent (no information in time may neutralise another sensationalist. The RPS starts the measures with a solid state (EPD, SIEMENS) dosimeter verified against a detector calibrated by an official laboratory of metrology. Large number of background measurements in different areas of the hospital are available by this method. The direct Hp and Hs, reading can be shown to the workers any time. The system is choose thinking in a good quickness/confidence relationship. The explanation that the measured values correspond to the natural background is not enough. The same dosemeter is given to a worker to make a measure in home, but one very different detector response when a call is received in a Mobil phone placed very near, built-up confusion. We know then that this kind of dosemeter, with CE Certificate and approved for use to the Nuclear Power Stations, when we bought it, was sensible to non ionizing radiation among other agents

No abstract available

[en] Formation of microchannels produced through 1 mm thick photostructurable glass (Foturan®) samples with two different lasers, an IR laser that gives 450 fs pulses at 1027 nm wavelength and an UV laser delivering 10 ns pulses at 355 nm wavelength, has been studied. After laser irradiation, the samples were submitted to thermal treatment and selective etching with hydrofluoric acid (HF) for microchannel formation. Two different acid concentrations (5% and 10%) were tested. It has been found that photoexcitation with the femtosecond laser can be related to a multiphoton absorption process requiring eight photons, and the critical dose of radiation for this process to occur has been determined. Etch rates with 10% HF are about two times higher than with 5% HF under equal irradiation conditions, while similar etch contrast ratios are attained. High etch rate ratios, together with small modified areas, have been found to play a determinant role in obtaining microchannels with the best aspect ratios. Use of the femtosecond laser in the IR allows the modification of smaller zones, but to the detriment of high etch rates.

[en] This paper presents the implementation and characterization of a single proof-mass wide-bandwidth pendulum accelerometer with fully-differential sensitivity in all three axes. The utilization of nano-gap electrodes (300 nm) boosts the electromechanical coupling significantly so that both increased sensitivity and high resonant frequency (f _res  >  15 kHz) can be attained, which extends the operational bandwidth as well as the dynamic range of the device using a miniaturized proof-mass of 450  ×  450 µm². Furthermore, increased air-damping from the nano-gap structure enables the stable operation of the device at moderate vacuum environment (1–10 Torr), which paves the way toward the single-chip inertial measurement unit by integrating a quasi-static accelerometer with resonant gyroscopes on a common substrate. The presented design is fabricated on a 40 µm thick silicon-on-insulator substrate and wafer-level vacuum-packaged with a TSV substrate at a moderate vacuum level (1–10 Torr). The device, interfaced with a switched capacitor ASIC exhibits sub-milli-g noise levels in a wide bandwidth exceeding 10 kHz and bias instability of 560 µg, 428.16 µg, 145 µg for the X, Y and Z axes, respectively. (paper)

[en] The Joint Research Centre Karlsruhe started operations in 1963 (until 2016 it was called Institute for Transuranium Elements, or J RC-ITU). The JRC Karlsruhe Hot Cells wing received its first irradiated fuel in November 1966. First designed as a post-irradiation examination (PIE) facility for Pu fast reactor fuel, the scope of activities of the hot cells evolved through the years, following the developments and the priority changes which affected R and D in the nuclear energy and the nuclear fuel safety fields. The hot cells acquired new functions and new tools, becoming a polyvalent platform capable to study commercial LWR fuel, advanced compounds, including fuel containing minor actinides for closed cycle, and special irradiation fuels covering a broad spectrum of applications: over the years the scientific projects have been focused on safety during irradiation and spent fuel safety (including pre-disposal and disposal studies. Normal and off-normal conditions, up to severe accident scenarios, are included in the portfolio of capabilities of the hot cells. All the research objectives were aligned with and contributed to European efforts in the nuclear fuel and fuel cycle research. The oral presentation will provide a schematic description of the main infrastructure configuration, and focus on the main technologies and research capabilities available in the hot cells. Special emphasis will be placed on the most recent tools and on the planned developments. (author)