Development and validation of a dynamic material flow analysis model for French copper cycle

This study performs a quantitative description of the copper life cycle at the scale of France from 2000 to 2009 with special focus on waste streams. The approach is based on substance flow analysis and includes data reconciliation. The model takes into account the relationships between economic system, resource consumption, product manufacturing, waste generation and pollution, thus broadening the traditional scope of process systems engineering. The more important results concern waste management since France exports most of its collected copper wastes because there is no industry for recycling low-grade scrap. The paper shows the interest of using substance flow analysis methodology coupled with data reconciliation to obtain a precise cartography of a substance flow inside a large area. Indeed, statistic data from institutional organisms and industries may vary from one source to the other, and the utilization of the redundancy of information is an efficient tool for obtaining more precise data. Moreover, the dynamic analysis allows modelling the stock evolution with more accuracy than in previous studies. Finally, theresults are compared with existing values for other countries or continents, and some perspectives concerning theuse of copper in France are given

Variation in patient position and impact on carbon-ion scanning beam distribution during prostate treatment

Purpose: We assessed the impact of changes in patient position on carbon-ion scanning beam distribution during treatment for prostate cancer.Methods: Sixty-eight patients were selected. Carbon-ion scanning dose was calculated. Two different planning target volumes (PTVs) were defined: PTV1 was the clinical target volume plus a setup margin for the anterior/lateral sides and posterior side, while PTV2 was the same as PTV1 minus the posterior side. Total prescribed doses of 34.4Gy (RBE) and 17.2Gy (RBE) were given to PTV1 and PTV2, respectively. To estimate the influence of the geometric variations on dose distribution, the dose was recalculated on the rigidly shifted single planning CT based on the 2D-3D rigid registration of the orthogonal X-ray images before and after treatment for the fraction of maximum positional changes.Results: Intrafractional patient positional change values average over all patients throughout the treatment course were less than target registration error = 2.00 mm and angular error = 1.27 deg. However, these maximum positional errors did not occur in all twelve-treatment fractions. Even though large positional changes occurred during irradiation in all treatment fractions, D95-PTV1 was over 98 % of the prescribed dose.Conclusions: Intrafractional patient positional changes occurred during treatment beam irradiation and degraded carbon-ion beam dose distribution. Our evaluation was not considered non-rigid deformations, albeit that, distribution was still within levels considered clinically acceptable.Advances in knowledge: Inter- and intra-fractional changes did not affect carbon-ion beam prostate treatment accuracy