Balle (projectile) | EPFL Graph Search

Une balle est un projectile d'arme à feu d'un calibre inférieur à , de type pistolet, carabine, fusil, pistolet mitrailleur, fusil mitrailleur… (au-delà, on parlera d'obus). Le mot « balle » désigne aussi parfois le projectile arrondi ou ovoïde en pierre ou en métal lancé par une fronde. On parlait d'obus à balles pour désigner des obus qui en explosant libéraient des balles de plomb durci (à l'antimoine et/ou à l'arsenic) dans toutes les directions ; ce sont en quelque sorte les ancêtres des armes à sous-munitions. Leur version la plus sophistiquée est l'obus Shrapnel, équipé d'un système mécanique réglable de programmation du moment de l'explosion, inventé durant la Première Guerre mondiale pour projeter dans toutes les directions une pluie de centaines de balles de plomb sur les hommes autrement protégés dans les tranchées. Histoire Bien avant l'invention des armes à feu, les toutes premières balles de plomb semblent avoir été des projectiles lancés à la fronde.

Elaboration d'outils pour l'investigation et l'assainissement des stands de tirs

Bruno Chappuis

Switzerland has about 6,000 shooting ranges, of which 2,000 are still in use. These activities generate a significant lead pollution. FOEN estimated 200 tons of lead is fired each year. This Master Project has been realized with the consultancy office CSD Ingénieurs Conseils SA in Lausanne. The project is divided into three parts related to investigations and remediation of shooting ranges. Eleven shooting ranges of the army and two communal shooting ranges have formed the field study of this project. On these sites, 20 samples were taken for laboratory analysis. Nearly 350 field tests with a portable X-ray fluorescence (XRF) were also performed. The first part of the study focused on sample preparation methods. Based on several assumptions, they often give conflicting results. It has been shown that not taking into account the size fraction between 1 cm and 2 mm leads to underestimating the lead concentration by 10% on average. Taking into account the bullets, and how, is even more important. The original content of lead in standard military bullets is 74% of the weight. A common use is to assume this content for the bullets found in soils samples. The lead content measured in bullets is from 64% for those in good shape to 17% for fragments. Lead seems to spread more easily than the steel jacket of the bullets. These results are of major importance for the calculation of the lead content of samples. A strong correlation between lead and bullet amount in soils has not been found. The condition of the bullets seemed to be a significant factor, but the representativeness of the samples was not sufficient due too few mass samples. Taking into account these results, a preparation method was proposed. The second part of the study concern leachate analysis. In particular, OSites leachate and OTD1 (acid) leachate was studied. These leachates are used respectively for polluted sites risk assessment and for choosing treatment solution of excavated materials. Correlations were looked for, between concentrations in leachate and soils parameters. CEC, clay content, organic carbon content and aquous pH has been used as soils parameters. Leachate OTD1 (neutral) has been preferred to leachate Osites for economic reasons, these two tests provide similar results for lead. Good correlations were obtained with non-linear models taking into account all the soils parameters. Models based only on the lead content and aqueous pH (better correlation) give interesting results, but have greater error. The third part focused on the study of geostatistics shooting ranges with fixed targets. Variogram were made from field measurements. A metric sampling grid metric was used. The variogram showed a remedy made from a range of 3 meters. Although the site shows a clear anisotropy, an isotropic spherical variogram with nugget effect has been adjusted. The data were insufficient to fit an anisotropic model. Calculations showed that the kriging interpolation provides better results than those obtained with conventional interpolation. The study also showed that the uncertainty of the kriging interpolation decreases when the mesh sampling is lower. An optimum between accuracy and number of tests could not be found, because the variogram used has too much variability. The results are very promising and will continue to be worked out in order to produce the means of zoning and estimate for the remediation of shooting range.

2009

Magnetic nanoparticle-induced hyperthermia with appropriate payloads: Paul Ehrlich's "magic (nano)bullet" for cancer theranostics?

Heinrich Hofmann, Swati Krishnan

Effective multimodal cancer management requires the optimal integration of diagnostic and therapeutic modalities. Radiation therapy, chemotherapy and immunotherapy, alone or in combination, are integral parts of various cancer treatment protocols. Hyperthermia at 39-45 degrees C is a potent radiosensitiser and has been shown to improve therapeutic outcomes in various tumours through its synergy with chemotherapy. Gene silencing approaches, using small interfering RNAs and microRNAs, are also being explored in clinical trials in oncology. The rapid developments in multifunctional nanoparticles provide ample opportunities to integrate both diagnostic and therapeutic modalities into a single effective cancer "theranostic" vector. Nanoparticles could extravasate passively into the tumour tissues in preference to the adjacent normal tissues by capitalizing on the enhanced permeability and retention effect. Tumour targeting might be further augmented by conjugating tumour-specific peptides and antibodies onto the surface of these nanoparticles or by activation through electromagnetic radiations, laser or ultrasound. Magnetic nanoparticles can induce hyperthermia in the presence of an alternating magnetic field, thereby multifunctionally with tumour-specific payloads empowering tumour specific radiotheranostics (for both imaging and radiotherapy), chemotherapy drug delivery, immunotherapy and gene silencing therapy. Such a (nano)bullet could realise the "magic bullet" conceived by Paul Ehrlich more than a century ago. This article discusses the various aspects of this "magic (nano)bullet" and the challenges that need to be addressed to usher in this new paradigm in modern cancer diagnostics and therapeutics. (C) 2016 Elsevier Ltd. All rights reserved.

Elsevier2016

Elaboration d'outils pour l'investigation et l'assainissement des stands de tirs

Bruno Chappuis

2009