Simulacija porarizacijskih mjerenja u elektrotvorbi kaona Monte Carlo metodom

Kaon electro-production experiments with polarized electron beam are planed at the Thomas Jefferson National Accelerator Facility (Virginia, USA) in order to complete the information on polarization response functions for the kaon electro-production reactions. The experiment uses the self analyzing property of the Λ recoil. The scattered electrons will be detected in coincidence with the kaons and the decay protons. This paper presents the simulation of this experiment which takes into account the spectrometer acceptances, multiple scattering and radiative corrections. The phase space distribution of the decay protons in the Λ center-of-mass system are generated in order to extract information on the polarization on the three directions. An experimental test with an unpolarized beam has been performed to estimate the efficiency of the method.U Thomas Jefferson National Accelerator Facility (Virginia, USA) predlažu se mjerenja elektrotvorbi s polariziranim elektronima radi cjelovitosti podataka o polarizacijskim funkcijama odziva u elektrotvorbi kaona. Mjerenje rabi samoanalizacijsko svojstvo odboja Λ čestice. Raspršeni elektroni opažat će se sudesno s kaonima i protonima. Ovaj rad predstavlja simulaciju tog eksperimenta u kojoj se uzimaju u obzir prihvati spektrometara, višestruko raspršenje i radijativne popravke. Izvodi se fazna raspodjela protona u centru mase Λ čestice radi dobivanja podataka o polarizaciji u trima smjerovima. Mjerenjem pomoću nepolariziranog snopa ocijenili smo učinkovitost metode

Simulacija porarizacijskih mjerenja u elektrotvorbi kaona Monte Carlo metodom

Kaon electro-production experiments with polarized electron beam are planed at the Thomas Jefferson National Accelerator Facility (Virginia, USA) in order to complete the information on polarization response functions for the kaon electro-production reactions. The experiment uses the self analyzing property of the Λ recoil. The scattered electrons will be detected in coincidence with the kaons and the decay protons. This paper presents the simulation of this experiment which takes into account the spectrometer acceptances, multiple scattering and radiative corrections. The phase space distribution of the decay protons in the Λ center-of-mass system are generated in order to extract information on the polarization on the three directions. An experimental test with an unpolarized beam has been performed to estimate the efficiency of the method.U Thomas Jefferson National Accelerator Facility (Virginia, USA) predlažu se mjerenja elektrotvorbi s polariziranim elektronima radi cjelovitosti podataka o polarizacijskim funkcijama odziva u elektrotvorbi kaona. Mjerenje rabi samoanalizacijsko svojstvo odboja Λ čestice. Raspršeni elektroni opažat će se sudesno s kaonima i protonima. Ovaj rad predstavlja simulaciju tog eksperimenta u kojoj se uzimaju u obzir prihvati spektrometara, višestruko raspršenje i radijativne popravke. Izvodi se fazna raspodjela protona u centru mase Λ čestice radi dobivanja podataka o polarizaciji u trima smjerovima. Mjerenjem pomoću nepolariziranog snopa ocijenili smo učinkovitost metode

The Geant4-DNA project

The Geant4-DNA project proposes to develop an open-source simulation software based and fully included in the general-purpose Geant4 Monte Carlo simulation toolkit. The main objective of this software is to simulate biological damages induced by ionising radiation at the cellular and sub-cellular scale. This project was originally initiated by the European Space Agency for the prediction of deleterious effects of radiation that may affect astronauts during future long duration space exploration missions. In this paper, the Geant4-DNA collaboration presents an overview of the whole ongoing project, including its most recent developments already available in the last Geant4 public release (9.3 BETA), as well as an illustration example simulating the direct irradiation of a chromatin fibre. Expected extensions involving several research domains, such as particle physics, chemistry and cellular and molecular biology, within a fully interdiciplinary activity of the Geant4 collaboration are also discussed.Comment: presented by S. Incerti at the ASIA SIMULATION CONFERENCE 2009, October 7-9, 2009, Ritsumeikan University, Shiga, Japa

Détermination du débit de filtration glomérulaire (DFG) au cours du diabète : Cockroft et Gault, MDRD ou CKD-EPI ?

Plusieurs paramètres peuvent être étudiés pour évaluer le rein. Parmi ceux-ci, le débit de filtration glomérulaire (DFG) a été déterminé avec les formules de Cockroft et Gault (CG), du Modification of Diet in Renal Disease (MDRD) et du Chronic Kidney Disease EPIdemiology Collaboration (CKD-EPI) et la formule la mieux adaptée pour le diabétique a été recherchée. Chez 59 diabétiques de type 1 (DT1) et 70 diabétiques de type 2 (DT2), le DFG a été déterminé avec les formules de CG, du MDRD et du CKD-EPI. Avec l’analyse statistique, les seuils de significativité ont été fixés pour p<0,05 ; T0α>1,96 et Z0α>1,96. Le MDRD est superposable au CKD-EPI chez les DT1 et DT2. Chez les DT1, le DFG moyen et la corrélation entre 1/créatininémie et DFG ne varient pas si CG ou CKD-EPI ; cependant, les sujets à DFG réduit (< 90 ml/min/1,73 m²) sont plus nombreux avec CG plutôt qu’avec CKD-EPI (66,10% vs 47,46% ; T0α=2,05). Chez les DT2, le DFG moyen et la proportion de sujets à DFG réduit sont indépendants de la formule utilisée, mais la corrélation entre 1/créatininémie et DFG est plus forte si CKD-EPI que CG (0,961 vs 0,632 ; Z0α=7,02). Ainsi, la formule la mieux adaptée pour la détermination du DFG serait CG chez les DT1 et CKD-EPI chez les DT2, sachant que CKD-EPI est équivalent à MDRD quel que soit le type de diabète.Mots clés : Cockroft et Gault - MDRD - CKD-EPI – débit de filtration glomérulaire (DFG) – diabète

Interaction of (3-Aminopropyl)triethoxysilane with Pulsed Ar-O 2 Afterglow: Application to Nanoparticles Synthesis

International audienceThe interaction of (3-Aminopropyl)triethoxysilane (APTES) with pulsed late Ar-O 2 afterglow is characterized by the synthesis of OH, CO and CO 2 in the gas phase as main by-products. Other minor species like CH, CN and C 2 H are also produced. We suggest that OH radicals are produced in a first step by dehydrogenation of APTES after interaction with oxygen atoms. In a second step, the molecule is oxidized by any O 2 state, to form peroxides that transform into by-products, break thus the precursor CC bonds. If oxidation is limited, i.e. a low duty cycle, fragmentation of the precursor is limited and produced nanoparticles keep the backbone structure of the precursor, but contain amide groups produced from the amine groups initially available in APTES. At high duty cycle, silicon-containing fragments contain some carbon and react together and produce nanoparticles with a non-silica-like structure

Phenomenology of the Deuteron Electromagnetic Form Factors

A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm^-1. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data.Comment: 18 pages (LaTeX), 2 figures Feb. 25: minor changes of content and in Table