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Sample records for geant4 influencia da

  1. Geant4-MT: bringing multi-threading into Geant4 production

    International Nuclear Information System (INIS)

    Ahn, S.; Apostolakis, J.; Cosmo, G.; Nowak, A.; Asai, M.; Brandt, D.; Dotti, A.; Coopermann, G.; Dong, X.; Jun, Soon Yung

    2013-01-01

    Geant4-MT is the multi-threaded version of the Geant4 particle transport code. The key goals for the design of Geant4-MT have been a) the need to reduce the memory footprint of the multi-threaded application compared to the use of separate jobs and processes; b) to create an easy migration of the existing applications; and c) to use efficiently many threads or cores, by scaling up to tens and potentially hundreds of workers. The first public release of a Geant4- MT prototype was made in 2011. We report on the revision of Geant4-MT for inclusion in the production-level release scheduled for end of 2013. This has involved significant re-engineering of the prototype in order to incorporate it into the main Geant4 development line, and the porting of Geant4-MT threading code to additional platforms. In order to make the porting of applications as simple as possible, refinements addressed the needs of standalone applications. Further adaptations were created to improve the fit with the frameworks of High Energy Physics experiments. We report on performances measurements on Intel Xeon TM , AMD Opteron TM the first trials of Geant4-MT on the Intel Many Integrated Cores (MIC) architecture, in the form of the Xeon Phi TM co-processor. These indicate near-linear scaling through about 200 threads on 60 cores, when holding fixed the number of events per thread. (authors)

  2. The GEANT4 Visualization System

    International Nuclear Information System (INIS)

    Allison, J

    2007-01-01

    The Geant4 Visualization System is a multi-driver graphics system designed to serve the Geant4 Simulation Toolkit. It is aimed at the visualization of Geant4 data, primarily detector descriptions and simulated particle trajectories and hits. It can handle a variety of graphical technologies simultaneously and interchangeably, allowing the user to choose the visual representation most appropriate to requirements. It conforms to the low-level Geant4 abstract graphical user interfaces and introduces new abstract classes from which the various drivers are derived and that can be straightforwardly extended, for example, by the addition of a new driver. It makes use of an extendable class library of models and filters for data representation and selection. The Geant4 Visualization System supports a rich set of interactive commands based on the Geant4 command system. It is included in the Geant4 code distribution and maintained and documented like other components of Geant4

  3. Integration of g4tools in Geant4

    International Nuclear Information System (INIS)

    Hřivnáčová, Ivana

    2014-01-01

    g4tools, that is originally part of the inlib and exlib packages, provides a very light and easy to install set of C++ classes that can be used to perform analysis in a Geant4 batch program. It allows to create and manipulate histograms and ntuples, and write them in supported file formats (ROOT, AIDA XML, CSV and HBOOK). It is integrated in Geant4 through analysis manager classes, thus providing a uniform interface to the g4tools objects and also hiding the differences between the classes for different supported output formats. Moreover, additional features, such as for example histogram activation or support for Geant4 units, are implemented in the analysis classes following users requests. A set of Geant4 user interface commands allows the user to create histograms and set their properties interactively or in Geant4 macros. g4tools was first introduced in the Geant4 9.5 release where its use was demonstrated in one basic example, and it is already used in a majority of the Geant4 examples within the Geant4 9.6 release. In this paper, we will give an overview and the present status of the integration of g4tools in Geant4 and report on upcoming new features.

  4. Geant4 in Scientific Literature

    CERN Document Server

    Pia, M G; Bell, Z W; Dressendorfer, P V

    2009-01-01

    The Geant4 reference paper published in Nuclear Instruments and Methods A in 2003 has become the most cited publication in the whole Nuclear Science and Technology category of Thomson-Reuter's Journal Citation Reports. It is currently the second most cited article among the publications authored by two major research institutes, CERN and INFN. An overview of Geant4 presence (and absence) in scholarly literature is presented; the patterns of Geant4 citations are quantitatively examined and discussed.

  5. Geant4 application in a Web browser

    International Nuclear Information System (INIS)

    Garnier, Laurent

    2014-01-01

    Geant4 is a toolkit for the simulation of the passage of particles through matter. The Geant4 visualization system supports many drivers including OpenGL[1], OpenInventor, HepRep[2], DAWN[3], VRML, RayTracer, gMocren[4] and ASCIITree, with diverse and complementary functionalities. Web applications have an increasing role in our work, and thanks to emerging frameworks such as Wt [5], building a web application on top of a C++ application without rewriting all the code can be done. Because the Geant4 toolkit's visualization and user interface modules are well decoupled from the rest of Geant4, it is straightforward to adapt these modules to render in a web application instead of a computer's native window manager. The API of the Wt framework closely matches that of Qt [6], our experience in building Qt driver will benefit for Wt driver. Porting a Geant4 application to a web application is easy, and with minimal effort, Geant4 users can replicate this process to share their own Geant4 applications in a web browser.

  6. Geant4 for the atlas electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Kordas, K.; Parrour, G.; Simion, St.

    2001-04-01

    We have recently employed the Geant4 tool-kit for the simulation of the barrel part of the ATLAS electromagnetic calorimeter. The two approaches used for the description of this geometry are presented and compared. Subsequently, we test the new simulation tool against the predictions of Geant3, the previous generation of the Geant simulation. We do so for muons. With the caveat of some differences in the detector geometry implementations in Geant4 and Geant3, we also show some extremely preliminary results for electrons. A comparison between the two geometry models has shown that there are very small differences, which are under study, but in general the tailored geometry approach is proven sound. We also investigated a way to reduce significantly the memory usage of the straight-forward 'static' geometry description. Comparing Geant4 against Geant3, we find that the mean energy depositions for 50 and 100 GeV muons are in agreement between the two simulations, but the two yield significantly different distributions. Preliminary results on electrons are encouraging and we plan to study these particles next, including comparisons with test beam data. (authors)

  7. Experiences on Grid Production for GEANT4

    CERN Document Server

    Lamanna, M; Méndez-Lorenzo, P; Moscicki, J; Ribon, A

    2007-01-01

    Geant4 is a worldwide collaboration of scientists and software engineers whose goal is to develop, maintain and provide support for the Geant4 package, representing a general purpose Monte Carlo toolkit for simulating the propagation of particles through matter. Geant4 is currently employed in a row of particle physics experiments (BaBar, HARP, ATLAS, CMS, LHCb), and is also applied in other areas like space science, medical applications, and radiation studies. Due to the complexity of the Geant4 code and to the broad spectrum of possible configurations - involving a variety of physical processes for different source particles, particle energies and target or shielding materials - an intensive testing of new release candidates is mandatory to thoroughly test each of its components, especially before major releases, generally twice a year. Regression tests are required to be performed by the Geant4 team within a short period of time (2 to 3 weeks), basically demanding vast computational resources (equivalent t...

  8. Validation Test of Geant4 Simulation of Electron Backscattering

    CERN Document Server

    Kim, Sung Hun; Basaglia, Tullio; Han, Min Cheol; Hoff, Gabriela; Kim, Chan Hyeong; Saracco, Paolo

    2015-01-01

    Backscattering is a sensitive probe of the accuracy of electron scattering algorithms implemented in Monte Carlo codes. The capability of the Geant4 toolkit to describe realistically the fraction of electrons backscattered from a target volume is extensively and quantitatively evaluated in comparison with experimental data retrieved from the literature. The validation test covers the energy range between approximately 100 eV and 20 MeV, and concerns a wide set of target elements. Multiple and single electron scattering models implemented in Geant4, as well as preassembled selections of physics models distributed within Geant4, are analyzed with statistical methods. The evaluations concern Geant4 versions from 9.1 to 10.1. Significant evolutions are observed over the range of Geant4 versions, not always in the direction of better compatibility with experiment. Goodness-of-fit tests complemented by categorical analysis tests identify a configuration based on Geant4 Urban multiple scattering model in Geant4 vers...

  9. Creating and improving multi-threaded Geant4

    CERN Document Server

    Dong, Xin; Apostolakis, John; Jarp, Sverre; Nowak, Andrzej; Asai, Makoto; Brandt, Daniel

    2012-01-01

    We document the methods used to create the multi-threaded prototype Geant4MT from a sequential version of Geant4. We cover the Source-to-Source transformations applied, and discuss the process of verifying the correctness of the Geant4MT toolkit and applications based on it. Tools to ensure that the results of a transformed multi-threaded application are exactly equal to the original sequential version are under development. Stand-alone or simple applications can be adapted within 1-2 working days. Geant4MT is shown to scale linearly on an 80-core computer. In the special case of a single worker thread on one core, 30% overhead has been observed. We explain the reasons for this and the improvements introduced to reduce this overhead.

  10. Software process in Geant4

    International Nuclear Information System (INIS)

    Cosmo, G.

    2001-01-01

    Since its erliest years of R and D, the GEANT4 simulation toolkit has been developed following software process standards which dictated the overall evolution of the project. The complexity of the software involved, the wide areas of application of the software product, the huge amount of code and Category complexity, the size and distributed nature of the Collaboration itself are all ingredients which involve and correlate together a wide variety of software processes. Although in 'production' and available to the public since December 1998, the GEANT4 software product includes Category Domains which are still under active development. Therefore they require different treatment also in terms of improvement of the development cycle, system testing and user support. The author is meant to describe some of the software processes as they are applied in GEANT4 for both development, testing and maintenance of the software

  11. Comparison Study on Low Energy Physics Model of GEANT4

    International Nuclear Information System (INIS)

    Park, So Hyun; Jung, Won Gyun; Suh, Tae Suk

    2010-01-01

    The Geant4 simulation toolkit provides improved or renewed physics model according to the version. The latest Geant4.9.3 which has been recoded by developers applies inserted Livermore data and renewed physics model to the low energy electromagnetic physics model. And also, Geant4.9.3 improved the physics factors by modified code. In this study, the stopping power and CSDA(Continuously Slowing Down Approximation) range data of electron or particles were acquired in various material and then, these data were compared with NIST(National Institute of Standards and Technology) data. Through comparison between data of Geant4 simulation and NIST, the improvement of physics model on low energy electromagnetic of Geant4.9.3 was evaluated by comparing the Geant4.9.2

  12. Geant4-DNA: overview and recent developments

    Science.gov (United States)

    Štěpán, Václav

    Space travel and high altitude flights are inherently associated with prolonged exposure to cosmic and solar radiation. Understanding and simulation of radiation action on cellular and subcellular level contributes to precise assessment of the associated health risks and remains a challenge of today’s radiobiology research. The Geant4-DNA project (http://geant4-dna.org) aims at developing an experimentally validated simulation platform for modelling of the damage induced by ionizing radiation at DNA level. The platform is based on the Geant4 Monte Carlo simulation toolkit. This project extends specific functionalities of Geant4 in following areas: The step-by-step single scattering modelling of elementary physical interactions of electrons, protons, alpha particles and light ions with liquid water and DNA bases, for the so-called “physical” stage. The modelling of the “physico-chemical and chemical” stages corresponding to the production, the diffusion, the chemical reactions occurring between chemical species produced by water radiolysis, and to the radical attack on the biological targets. Physical and chemical stage simulations are combined with biological target models on several scales, from DNA double helix, through nucleosome, to chromatin segments and cell geometries. In addition, data mining clustering algorithms have been developed and optimised for the purpose of DNA damage scoring in simulated tracks. Experimental measurements on pBR322 plasmid DNA are being carried out in order to validate the Geant4-DNA models. The plasmid DNA has been irradiated in dry conditions by protons with energies from 100 keV to 30 MeV and in aqueous conditions, with and without scavengers, by 30 MeV protons, 290 MeV/u carbon and 500 MeV/u iron ions. Agarose gel electrophoresis combined with enzymatic treatment has been used to measure the resulting DNA damage. An overview of the developments undertaken by the Geant4-DNA collaboration including a description of

  13. GPU in Physics Computation: Case Geant4 Navigation

    CERN Document Server

    Seiskari, Otto; Niemi, Tapio

    2012-01-01

    General purpose computing on graphic processing units (GPU) is a potential method of speeding up scientific computation with low cost and high energy efficiency. We experimented with the particle physics simulation toolkit Geant4 used at CERN to benchmark its geometry navigation functionality on a GPU. The goal was to find out whether Geant4 physics simulations could benefit from GPU acceleration and how difficult it is to modify Geant4 code to run in a GPU. We ported selected parts of Geant4 code to C99 & CUDA and implemented a simple gamma physics simulation utilizing this code to measure efficiency. The performance of the program was tested by running it on two different platforms: NVIDIA GeForce 470 GTX GPU and a 12-core AMD CPU system. Our conclusion was that GPUs can be a competitive alternate for multi-core computers but porting existing software in an efficient way is challenging.

  14. Geant4-DNA simulation of electron slowing-down spectra in liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Incerti, S., E-mail: sebastien.incerti@tdt.edu.vn [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Univ. Bordeaux, CENBG, UMR 5797, F-33170, Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Kyriakou, I. [Medical Physics Laboratory, University of Ioannina Medical School, 45110 Ioannina (Greece); Tran, H.N. [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam)

    2017-04-15

    This work presents the simulation of monoenergetic electron slowing-down spectra in liquid water by the Geant4-DNA extension of the Geant4 Monte Carlo toolkit (release 10.2p01). These spectra are simulated for several incident energies using the most recent Geant4-DNA physics models, and they are compared to literature data. The influence of Auger electron production is discussed. For the first time, a dedicated Geant4-DNA example allowing such simulations is described and is provided to Geant4 users, allowing further verification of Geant4-DNA track structure simulation capabilities.

  15. The Geant4 Bertini Cascade

    Energy Technology Data Exchange (ETDEWEB)

    Wright, D.H.; Kelsey, M.H.

    2015-12-21

    One of the medium energy hadron–nucleus interaction models in the GEANT4 simulation toolkit is based partly on the Bertini intranuclear cascade model. Since its initial appearance in the toolkit, this model has been largely re-written in order to extend its physics capabilities and to reduce its memory footprint. Physics improvements include extensions in applicable energy range and incident particle types, and improved hadron–nucleon cross-sections and angular distributions. Interfaces have also been developed which allow the model to be coupled with other GEANT4 models at lower and higher energies. The inevitable speed reductions due to enhanced physics have been mitigated by memory and CPU efficiency improvements. Details of these improvements, along with selected comparisons of the model to data, are discussed.

  16. Quantitative Test of the Evolution of Geant4 Electron Backscattering Simulation

    CERN Document Server

    Basaglia, Tullio; Hoff, Gabriela; Kim, Chan Hyeong; Kim, Sung Hun; Pia, Maria Grazia; Saracco, Paolo

    2016-01-01

    Evolutions of Geant4 code have affected the simulation of electron backscattering with respect to previously published results. Their effects are quantified by analyzing the compatibility of the simulated electron backscattering fraction with a large collection of experimental data for a wide set of physics configuration options available in Geant4. Special emphasis is placed on two electron scattering implementations first released in Geant4 version 10.2: the Goudsmit-Saunderson multiple scattering model and a single Coulomb scattering model based on Mott cross section calculation. The new Goudsmit-Saunderson multiple scattering model appears to perform equally or less accurately than the model implemented in previous Geant4 versions, depending on the electron energy. The new Coulomb scattering model was flawed from a physics point of view, but computationally fast in Geant4 version 10.2; the physics correction released in Geant4 version 10.2p01 severely degrades its computational performance. Evolutions in ...

  17. Geant4 2005 10. user conference and collaboration workshop. Slides

    International Nuclear Information System (INIS)

    Maire, M.; Amako, K.; Agapov, I.; Allison, J.; Amako, K.; Anah, J.; Apostolakis, J.; Asai, M.; Aso, T.; Barrand, G.; Becheva, E.; Berthoumieux, E.; Bongrand, M.; Boudard, A.; Canchel, G.; Capra, R.; Carlier, Th.; Chambon, P.; Chipaux, R.; Cognet, M.A.; Cornelius, I.; Cosmo, G.; Beenhouwer, J. de; Derreumaux, S.; Desbree, A.; Descourt, P.; Dridi, W.; Ersmark, T.; Faddegon, B.; Ferrer, L.; Flacco, A.; Folger, G.; Francis, S.; Giovinazzo, J.; Glinec, Y.; Godart, J.; Goncalves, P.; Gottschlag, H.; Grichine, V.; Guatelli, S.; Gudowska, I.; Guemnie Tafo, A.; Gueye, P.; Gumplinger, P.; Gurriaran, R.; Hannachi, F.; Heikkinen, A.; Hill, D.; Honore, P.F.; Howard, A.; Hrivnacova, I.; Hubert, X.; Incerti, S.; Ivanchenko, V.; Jacquemier, J.; Jones, F.; Kerhoas-Cavata, S.; Klem, J.; Koi, T.; Kosov, M.; Labalme, M.; Lang, N.; Lemercier, M.; Lemiere, Y.; Leroy, P.; Link, O.; Liu, B.; Lydon, J.; Maire, M.; Marchand, D.; Marquet, Ch.; Mascialino, B.; Matea, I.; Mccormick, J.; Mclaren, I.; Merchant, M.; Miceli, A.; Mine, Ph.; Moretto, Ph.; Mount, R.; Murakami, K.; Nachab, H.; Nehmeh, S.; Nieminen, P.; Paganetti, H.; Pallon, J.; Pandola, L.; Perl, J.; Perrot, F.; Pia Maria, G.; Piqueras, I.; Pouthier, Th.; Pshenichnov, I.; Raaijmakers, A.; Raaymakers, B.; Reuillon, R.; Ribon, A.; Rodrigues, P.; Rogel, G.; Salehzahi, F.; Santin, G.; Sasaki, T.; Schubert, M.; Seznec, H.; Shipley, D.; Skaza, F.; Thiam Cheick, O.; Tome, B.; Traneus, E.; Trindade, A.; Truscott, P.; Vacanti, G.; Verderi, M.; Watase, Y.; Wright, D.; Yarba, J.; Yoshida, H.; Zacharatou-Jarlskog, Ch.; Zhang, Q.

    2005-01-01

    Originally developed for the simulation of large scale particle physics experiments, the field of applications of the conferences Geant4 is growing fast worldwide especially at the physics medicine biology frontier. In this framework the 2005 Geant4 conference was dedicated to simulations with a strong interest at the physics medicine biology frontier. In particular the following topics were discussed: review of simulation applications for medicine, validation of Geant4 models for medical physics, simulation of radiotherapy and irradiation setups, treatment planning in radiotherapy, dosimetry, parallelization, imaging techniques, data handling, related GRID developments and applications and the Geant4 DNA project with related Monte Carlo tools. Slides are provided. (A.L.B.)

  18. Geant4 2005 10. user conference and collaboration workshop. Slides

    Energy Technology Data Exchange (ETDEWEB)

    Maire, M; Amako, K; Agapov, I; Allison, J; Amako, K; Anah, J; Apostolakis, J; Asai, M; Aso, T; Barrand, G; Becheva, E; Berthoumieux, E; Bongrand, M; Boudard, A; Canchel, G; Capra, R; Carlier, Th; Chambon, P; Chipaux, R; Cognet, M A; Cornelius, I; Cosmo, G; Beenhouwer, J de; Derreumaux, S; Desbree, A; Descourt, P; Dridi, W; Ersmark, T; Faddegon, B; Ferrer, L; Flacco, A; Folger, G; Francis, S; Giovinazzo, J; Glinec, Y; Godart, J; Goncalves, P; Gottschlag, H; Grichine, V; Guatelli, S; Gudowska, I; Guemnie Tafo, A; Gueye, P; Gumplinger, P; Gurriaran, R; Hannachi, F; Heikkinen, A; Hill, D; Honore, P F; Howard, A; Hrivnacova, I; Hubert, X; Incerti, S; Ivanchenko, V; Jacquemier, J; Jones, F; Kerhoas-Cavata, S; Klem, J; Koi, T; Kosov, M; Labalme, M; Lang, N; Lemercier, M; Lemiere, Y; Leroy, P; Link, O; Liu, B; Lydon, J; Maire, M; Marchand, D; Marquet, Ch; Mascialino, B; Matea, I; Mccormick, J; Mclaren, I; Merchant, M; Miceli, A; Mine, Ph; Moretto, Ph; Mount, R; Murakami, K; Nachab, H; Nehmeh, S; Nieminen, P; Paganetti, H; Pallon, J; Pandola, L; Perl, J; Perrot, F; Pia Maria, G; Piqueras, I; Pouthier, Th; Pshenichnov, I; Raaijmakers, A; Raaymakers, B; Reuillon, R; Ribon, A; Rodrigues, P; Rogel, G; Salehzahi, F; Santin, G; Sasaki, T; Schubert, M; Seznec, H; Shipley, D; Skaza, F; Thiam Cheick, O; Tome, B; Traneus, E; Trindade, A; Truscott, P; Vacanti, G; Verderi, M; Watase, Y; Wright, D; Yarba, J; Yoshida, H; Zacharatou-Jarlskog, Ch; Zhang, Q

    2005-07-01

    Originally developed for the simulation of large scale particle physics experiments, the field of applications of the conferences Geant4 is growing fast worldwide especially at the physics medicine biology frontier. In this framework the 2005 Geant4 conference was dedicated to simulations with a strong interest at the physics medicine biology frontier. In particular the following topics were discussed: review of simulation applications for medicine, validation of Geant4 models for medical physics, simulation of radiotherapy and irradiation setups, treatment planning in radiotherapy, dosimetry, parallelization, imaging techniques, data handling, related GRID developments and applications and the Geant4 DNA project with related Monte Carlo tools. Slides are provided. (A.L.B.)

  19. Recent progress of Geant4 electromagnetic physics for calorimeter simulation

    Science.gov (United States)

    Incerti, S.; Ivanchenko, V.; Novak, M.

    2018-02-01

    We report on recent progress in the Geant4 electromagnetic (EM) physics sub-packages. New interfaces and models introduced recently in Geant4 10.3 are already used in LHC applications and may be useful for any type of simulation. Additional developments for EM physics are available with the new public version Geant4 10.4 (December, 2017). Important developments for calorimetry applications were carried out for the modeling of single and multiple scattering of charged particles. Corrections to scattering of positrons and to sampling of displacement have recently been added to the Geant4 default Urban model. The fully theory-based Goudsmit-Saunderson (GS) model for electron/positron multiple scattering was recently reviewed and a new improved version is available in Geant4 10.4. For testing purposes for novel calorimeters we provide a configuration of electron scattering based on the GS model or on the single scattering model (SS) instead of the Urban model. In addition, the GS model with Mott corrections enabled is included in the option4 EM physics constructor. This EM configuration provides the most accurate results for scattering of electrons and positrons.

  20. Geant4 hadronic and electromagnetic validation tests in LHCb

    CERN Document Server

    Griffith, Peter Noel

    2016-01-01

    LHCb uses Geant4 to simulate the interactions of particles with the detector material and components. The simulation response can vary significantly due to modification of material description, of detector geometry, or of the Geant4 toolkit itself. Therefore, an extensive variety of tools have been developed to study the effects of Geant4 modification on the LHCb simulation framework and on stand-alone environments within the LHCb software infrastructure. These tools have proven to be very effective for investigating new and alternative models provided by Geant4, and also in identifying and fixing anomalous behaviours that arise from changes. The next goal is to have these validation tests run autonomously and periodically, alerting the relevant users when problems are detected. Quick and easy comparison of the results from different software versions and simulation models will be made possible through the web interface of the LHCb Performance and Regression testing system, LHCbPR.

  1. Lightgrid-an agile distributed computing architecture for Geant4

    International Nuclear Information System (INIS)

    Young, Jason; Perry, John O.; Jevremovic, Tatjana

    2010-01-01

    A light weight grid based computing architecture has been developed to accelerate Geant4 computations on a variety of network architectures. This new software is called LightGrid. LightGrid has a variety of features designed to overcome current limitations on other grid based computing platforms, more specifically, smaller network architectures. By focusing on smaller, local grids, LightGrid is able to simplify the grid computing process with minimal changes to existing Geant4 code. LightGrid allows for integration between Geant4 and MySQL, which both increases flexibility in the grid as well as provides a faster, reliable, and more portable method for accessing results than traditional data storage systems. This unique method of data acquisition allows for more fault tolerant runs as well as instant results from simulations as they occur. The performance increases brought along by using LightGrid allow simulation times to be decreased linearly. LightGrid also allows for pseudo-parallelization with minimal Geant4 code changes.

  2. Parallel Geometries in Geant4 foundation and recent enhancements

    CERN Document Server

    Apostolakis, J; Cosmo, G; Howard, A; Ivanchenko, V; Verderi, M

    2009-01-01

    The Geant4 software toolkit simulates the passage of particles through matter. It is utilized in high energy and nuclear physics experiments, in medical physics and space applications. For many applications it is necessary to measure particle fluxes and radiation doses in parts of the setup where there are complex structures. To undertake this in a flexible way, Geant4 has tools to create and use additional, parallel, geometrical hierarchies within a single application. A separate, parallel geometry can be used for each one amongst shower parameterization, event biasing, scoring of radiation, and/or the creation of hits in detailed readout structures. We describe the existing basic capabilities of the Geant4 toolkit to create multiple geometries and the recent major enhancements undertaken to streamline, enhance and extend these. New functionality enables Geant4 developers to offer new embedded schemes for scoring (requiring no user C++ code); has simplified the implementation of processes or capabilities usi...

  3. Test of GEANT3 and GEANT4 nuclear models for 160 MeV protons stopping in CH2

    International Nuclear Information System (INIS)

    Paganetti, H.; Gottschalk, B.

    2003-01-01

    Monte Carlo simulations are used for many problems in proton radiation therapy, some of which are sensitive to the nuclear interaction model. The available models have been little tested in the regime of interest, namely in their ability to predict the secondary particle yield, including their angle and energy, when 70-250 MeV protons stop in various materials. The present study provides one such test in carbon, complementing a previous one in copper. Using a multilayer Faraday cup we have measured the projected range distribution of charged nuclear secondaries from 160 MeV protons stopping in polyethylene (CH 2 ). To test the popular GEANT Monte Carlo we have simulated the experiment with GEANT3 using the 'Gheisha' (default) and 'Fluka' models and with GEANT4.5 using the 'low-energy' and 'precompound' models. The GEANT3/Fluka and GEANT4/precompound simulations agree moderately well with the observed range distribution. The data are given in a convenient form for testing other Monte Carlo programs

  4. Performance Evaluation of Multithreaded Geant4 Simulations Using an Intel Xeon Phi Cluster

    Directory of Open Access Journals (Sweden)

    P. Schweitzer

    2015-01-01

    Full Text Available The objective of this study is to evaluate the performances of Intel Xeon Phi hardware accelerators for Geant4 simulations, especially for multithreaded applications. We present the complete methodology to guide users for the compilation of their Geant4 applications on Phi processors. Then, we propose series of benchmarks to compare the performance of Xeon CPUs and Phi processors for a Geant4 example dedicated to the simulation of electron dose point kernels, the TestEm12 example. First, we compare a distributed execution of a sequential version of the Geant4 example on both architectures before evaluating the multithreaded version of the Geant4 example. If Phi processors demonstrated their ability to accelerate computing time (till a factor 3.83 when distributing sequential Geant4 simulations, we do not reach the same level of speedup when considering the multithreaded version of the Geant4 example.

  5. MCNPX and GEANT4 simulation of γ-ray polymeric shields

    Indian Academy of Sciences (India)

    However, both methods need benchmarking with experimental or standard data. Monte ... elements as it was defined for MCNPX and GEANT4 input materials. ... In GEANT4, photon and neutron libraries were implemented using EMLOW6.19.

  6. An XML description of detector geometries for GEANT4

    International Nuclear Information System (INIS)

    Figgins, J.; Walker, B.; Comfort, J.R.

    2006-01-01

    A code has been developed that enables the geometry of detectors to be specified easily and flexibly in the XML language, for use in the Monte Carlo program GEANT4. The user can provide clear documentation of the geometry without being proficient in the C++ language of GEANT4. The features and some applications are discussed

  7. GEANT 4: an Object-Oriented toolkit for simulation in HEP

    CERN Multimedia

    Kent, P; Sirotenko, V; Komogorov, M; Pavliouk, A; Greeniaus, G L; Kayal, P I; Routenburg, P; Tanaka, S; Duellmann, D; Innocente, V; Paoli, S; Ranjard, F; Riccardi, F; Ruggier, M; Shiers, J; Egli, S; Kimura, A; Urban, P; Prior, S; Walkden, A; Forti, A; Magni, S; Strahl, K; Kokoulin, R; Braune, K; Volcker, C; Ullrich, T; Takahata, M; Nieminen, P; Ballocchi, G; Mora De Freitas, P; Verderi, M; Rybine, A; Langeveld, W; Nagamatsu, M; Hamatsu, R; Katayama, N; Chuma, J; Felawka, L; Gumplinger, P; Axen, D

    2002-01-01

    %RD44 %title\\\\ \\\\The GEANT4 software has been developed by a world-wide collaboration of about 100 scientists from over 40 institutions and laboratories participating in more than 10 experiments in Europe, Russia, Japan, Canada, and the United States. The GEANT4 detector simulation toolkit has been designed for the next generation of High Energy Physics (HEP) experiments, with primary requirements from the LHC, the CP violation, and the heavy ions experiments. In addition, GEANT4 also meets the requirements from the space and medical communities, thanks to very low energy extensions developed in a joint project with the European Space Agency (ESA). GEANT4 has exploited advanced software engineering techniques (for example PSS-05) and Object-Oriented technology to improve the validation process of the physics results, and in the same time to make possible the distributed software design and development in the world-wide collaboration. Fifteen specialised working groups have been responsible for fields as diver...

  8. Nuclear spectroscopy with Geant4. The superheavy challenge

    Science.gov (United States)

    Sarmiento, Luis G.

    2016-12-01

    The simulation toolkit Geant4 was originally developed at CERN for high-energy physics. Over the years it has been established as a swiss army knife not only in particle physics but it has seen an accelerated expansion towards nuclear physics and more recently to medical imaging and γ- and ion- therapy to mention but a handful of new applications. The validity of Geant4 is vast and large across many particles, ions, materials, and physical processes with typically various different models to choose from. Unfortunately, atomic nuclei with atomic number Z > 100 are not properly supported. This is likely due to the rather novelty of the field, its comparably small user base, and scarce evaluated experimental data. To circumvent this situation different workarounds have been used over the years. In this work the simulation toolkit Geant4 will be introduced with its different components and the effort to bring the software to the heavy and superheavy region will be described.

  9. Progress in Geant4 Electromagnetic Physics Modelling and Validation

    International Nuclear Information System (INIS)

    Apostolakis, J; Burkhardt, H; Ivanchenko, V N; Asai, M; Bagulya, A; Grichine, V; Brown, J M C; Chikuma, N; Cortes-Giraldo, M A; Elles, S; Jacquemier, J; Guatelli, S; Incerti, S; Kadri, O; Maire, M; Urban, L; Pandola, L; Sawkey, D; Toshito, T; Yamashita, T

    2015-01-01

    In this work we report on recent improvements in the electromagnetic (EM) physics models of Geant4 and new validations of EM physics. Improvements have been made in models of the photoelectric effect, Compton scattering, gamma conversion to electron and muon pairs, fluctuations of energy loss, multiple scattering, synchrotron radiation, and high energy positron annihilation. The results of these developments are included in the new Geant4 version 10.1 and in patches to previous versions 9.6 and 10.0 that are planned to be used for production for run-2 at LHC. The Geant4 validation suite for EM physics has been extended and new validation results are shown in this work. In particular, the effect of gamma-nuclear interactions on EM shower shape at LHC energies is discussed. (paper)

  10. Geant4-related R&D for new particle transport methods

    CERN Document Server

    Augelli, M; Evans, T; Gargioni, E; Hauf, S; Kim, C H; Kuster, M; Pia, M G; Filho, P Queiroz; Quintieri, L; Saracco, P; Santos, D Souza; Weidenspointner, G; Zoglauer, A

    2009-01-01

    A R&D project has been launched in 2009 to address fundamental methods in radiation transport simulation and revisit Geant4 kernel design to cope with new experimental requirements. The project focuses on simulation at different scales in the same experimental environment: this set of problems requires new methods across the current boundaries of condensed-random-walk and discrete transport schemes. An exploration is also foreseen about exploiting and extending already existing Geant4 features to apply Monte Carlo and deterministic transport methods in the same simulation environment. An overview of this new R&D associated with Geant4 is presented, together with the first developments in progress.

  11. A tool to convert CAD models for importation into Geant4

    Science.gov (United States)

    Vuosalo, C.; Carlsmith, D.; Dasu, S.; Palladino, K.; LUX-ZEPLIN Collaboration

    2017-10-01

    The engineering design of a particle detector is usually performed in a Computer Aided Design (CAD) program, and simulation of the detector’s performance can be done with a Geant4-based program. However, transferring the detector design from the CAD program to Geant4 can be laborious and error-prone. SW2GDML is a tool that reads a design in the popular SOLIDWORKS CAD program and outputs Geometry Description Markup Language (GDML), used by Geant4 for importing and exporting detector geometries. Other methods for outputting CAD designs are available, such as the STEP format, and tools exist to convert these formats into GDML. However, these conversion methods produce very large and unwieldy designs composed of tessellated solids that can reduce Geant4 performance. In contrast, SW2GDML produces compact, human-readable GDML that employs standard geometric shapes rather than tessellated solids. This paper will describe the development and current capabilities of SW2GDML and plans for its enhancement. The aim of this tool is to automate importation of detector engineering models into Geant4-based simulation programs to support rapid, iterative cycles of detector design, simulation, and optimization.

  12. Beam Tools for Geant4 (User's Guide)

    International Nuclear Information System (INIS)

    V.Daniel Elvira, Paul Lebrun and Panagiotis Spentzouris email daniel@fnal.gov

    2002-01-01

    Geant4 is a tool kit developed by a collaboration of physicists and computer professionals in the high energy physics field for simulation of the passage of particles through matter. The motivation for the development of the Beam Tools is to extend the Geant4 applications to accelerator physics. The Beam Tools are a set of C++ classes designed to facilitate the simulation of accelerator elements: r.f. cavities, magnets, absorbers, etc. These elements are constructed from Geant4 solid volumes like boxes, tubes, trapezoids, or spheers. There are many computer programs for beam physics simulations, but Geant4 is ideal to model a beam through a material or to integrate a beam line with a complex detector. There are many such examples in the current international High Energy Physics programs. For instance, an essential part of the RandD associated with the Neutrino Source/Muon Collider accelerator is the ionization cooling channel, which is a section of the system aimed to reduce the size of the muon beam in phase space. The ionization cooling technique uses a combination of linacs and light absorbers to reduce the transverse momentum and size of the beam, while keeping the longitudinal momentum constant. The MuCool/MICE (muon cooling) experiments need accurate simulations of the beam transport through the cooling channel in addition to a detailed simulation of the detectors designed to measure the size of the beam. The accuracy of the models for physics processes associated with muon ionization and multiple scattering is critical in this type of applications. Another example is the simulation of the interaction region in future accelerators. The high luminosity and background environments expected in the Next Linear Collider (NLC) and the Very Large Hadron Collider (VLHC) pose great demand on the detectors, which may be optimized by means of a simulation of the detector-accelerator interface

  13. Neutron transport simulation in high speed moving media using Geant4

    Science.gov (United States)

    Li, G.; Ciungu, B.; Harrisson, G.; Rogge, R. B.; Tun, Z.; van der Ende, B. M.; Zwiers, I.

    2017-12-01

    A method using Geant4 to simulate neutron transport in moving media is described. The method is implanted in the source code of the software since Geant4 does not intrinsically support a moving object. The simulation utilizes the existing physical model and data library in Geant4, combined with frame transformations to account for the effect of relative velocity between neutrons and the moving media. An example is presented involving a high speed rotating cylinder to verify this method and show the effect of moving media on neutron transport.

  14. Recent developments in GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Allison, J. [Geant4 Associates International Ltd., 9 Royd Terrace, Hebden Bridge HX7 7BT (United Kingdom); The University of Manchester, School of Physics and Astronomy, Manchester M13 9PL (United Kingdom); Amako, K. [KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Geant4 Associates International Ltd., 9 Royd Terrace, Hebden Bridge HX7 7BT (United Kingdom); Apostolakis, J. [CERN, 1211 Genéve 23 (Switzerland); Arce, P. [CIEMAT, Medical Applications Unit, Avenida Complutense 40, 28040 Madrid (Spain); Asai, M. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Aso, T. [National Institute of Technology, Toyama College, 1-2 Ebie Neriya, Imizu, Toyama 9330293 (Japan); Bagli, E. [INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara (Italy); Bagulya, A. [Lebedev Physical Institute, Leninskii Pr. 53, Moscow 119991 (Russian Federation); Banerjee, S. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Barrand, G. [IN2P3/LAL, Universite Paris-Sud, Orsay (France); Beck, B.R. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Bogdanov, A.G. [National Research Nuclear University (Moscow Engineering Physics Institute), Kashirskoe shosse 31, Moscow 115409 (Russian Federation); Brandt, D. [SSW Trading, Am Knick 4, Oststeinbek (Germany); Brown, J.M.C. [Queen' s University Belfast, School of Mathematics and Physics, University Road, Belfast, Northern Ireland BT7 1NN (United Kingdom); Burkhardt, H. [CERN, 1211 Genéve 23 (Switzerland); Canal, Ph. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Cano-Ott, D. [CIEMAT, Centro de Investigaciones Energéticas Medioambientales y Tecnólogicas, Avenida Complutense 40, 28040 Madrid (Spain); Chauvie, S. [Sante Croce e Carle Hospital, Via Coppino 26, I-12100 Cuneo (Italy); and others

    2016-11-01

    GEANT4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. The adaptation of GEANT4 to multithreading, advances in physics, detector modeling and visualization, extensions to the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here. - Highlights: • Multithreading resulted in a smaller memory footprint and nearly linear speed-up. • Scoring options, faster geometry primitives, more versatile visualization were added. • Improved electromagnetic and hadronic models and cross sections were developed. • Reverse Monte Carlo and general biasing methods were added. • Physics validation efforts were expanded and new validation tools were added.

  15. Beam simulation tools for GEANT4 (and neutrino source applications)

    International Nuclear Information System (INIS)

    V.Daniel Elvira, Paul Lebrun and Panagiotis Spentzouris email daniel@fnal.gov

    2002-01-01

    Geant4 is a tool kit developed by a collaboration of physicists and computer professionals in the High Energy Physics field for simulation of the passage of particles through matter. The motivation for the development of the Beam Tools is to extend the Geant4 applications to accelerator physics. Although there are many computer programs for beam physics simulations, Geant4 is ideal to model a beam going through material or a system with a beam line integrated to a complex detector. There are many examples in the current international High Energy Physics programs, such as studies related to a future Neutrino Factory, a Linear Collider, and a very Large Hadron Collider

  16. GEANT4 Tuning For pCT Development

    International Nuclear Information System (INIS)

    Yevseyeva, Olga; Assis, Joaquim T. de; Evseev, Ivan; Schelin, Hugo R.; Paschuk, Sergei A.; Milhoretto, Edney; Setti, Joao A. P.; Diaz, Katherin S.; Hormaza, Joel M.; Lopes, Ricardo T.

    2011-01-01

    Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. Moreover, the spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through aluminum absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadrontherapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code, or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development.

  17. Physical models implemented in the Geant4-DNA extension of the Geant-4 toolkit for calculating initial radiation damage at the molecular level

    International Nuclear Information System (INIS)

    Villagrasa, C.; Francis, Z.; Incerti, S.

    2011-01-01

    The ROSIRIS project aims to study the radiobiology of integrated systems for medical treatment optimisation using ionising radiations and evaluate the associated risk. In the framework of this project, one research focus is the interpretation of the initial radio-induced damage in DNA created by ionising radiation (and detected by γH2AX foci analysis) from the track structure of the incident particles. In order to calculate the track structure of ionising particles at a nano-metric level, the Geant4 Monte Carlo toolkit was used. Geant4 (Object Oriented Programming Architecture in C++) offers a common platform, available free to all users and relatively easy to use. Nevertheless, the current low-energy threshold for electromagnetic processes in GEANT4 is set to 1 keV (250 eV using the Livermore processes), which is an unsuitable value for nano-metric applications. To lower this energy threshold, the necessary interaction processes and models were identified, and the corresponding available cross sections collected from the literature. They are mostly based on the plane-wave Born approximation (first Born approximation, or FBA) for inelastic interactions and on semi-empirical models for energies where the FBA fails (at low energies). In this paper, the extensions that have been introduced into the 9.3 release of the Geant4 toolkit are described, the so-called Geant4-DNA extension, including a set of processes and models adapted in this study and permitting the simulation of electron (8 eV -1 MeV), proton (100 eV-100 MeV) and alpha particle (1 keV-10 MeV) interactions in liquid water. (authors)

  18. New evaluated neutron cross section libraries for the GEANT4 code

    International Nuclear Information System (INIS)

    Mendoza, E.; Cano-Ott, D.; Guerrero, C.; Capote, R.

    2012-04-01

    The so-called High Precision neutron physics model implemented in the GEANT4 simulation package allows simulating the transport of neutrons with energies up to 20 MeV. It relies on the G4NDL cross section libraries, prepared by the GEANT4 collaboration from evaluated cross section files and distributed freely together with the code. Even though the performance of the G4NDL library has been improved over the time, users running complex simulations which involve the transport of neutrons do need more flexibility, in particular when assessing the uncertainties in the simulation results due to the neutron (and hence the nuclear) data library used. For this reason, a software tool has been developed for transforming any evaluated neutron cross section library in the ENDF-6 format into the G4NDL format. Furthermore, eight different releases of ENDF-B, JEFF, JENDL, CENDL and BROND national libraries have been translated into the G4NDL format and are distributed by the IAEA nuclear data service at www-nds.iaea.org/geant4. In this way, GEANT4 users have access to the complete list of standard evaluated neutron data libraries when performing Monte Carlo simulations with GEANT4. Consistency checks and a first validation of the libraries have been made following the methods described in this report. (author)

  19. Status of the physics validation studies using Geant4 in ATLAS

    CERN Document Server

    AUTHOR|(CDS)2108477

    2003-01-01

    The new simulation for the ATLAS detector at LHC is performed using Geant4 in a complete OO/C++ environment. In this framework the simulation of the various test beams for the different ATLAS subdetectors offers an excellent opportunity to perform physics validation studies over a wide range of physics domains: the electromagnetic processes, the individual hadronic interactions, the electromagnetic and hadronic signals in calorimeters. The simulation is implemented by paying special attention to all details of the experimental layout and by testing all possible physics processes which may be of relevance to the specific detector under test: the resulting simulation programs are often more detailed than the corresponding Geant3-based simulation suites. In this paper we present relevant features of muon, electron and pion signals in various ATLAS detectors. All remaining discrepancies between Geant4 and test-beam data are currently being addressed and progress is continuous. This work shows that Geant4 is becom...

  20. Low-energy electron dose-point kernel simulations using new physics models implemented in Geant4-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Bordes, Julien, E-mail: julien.bordes@inserm.fr [CRCT, UMR 1037 INSERM, Université Paul Sabatier, F-31037 Toulouse (France); UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, F-31037 (France); Incerti, Sébastien, E-mail: incerti@cenbg.in2p3.fr [Université de Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Lampe, Nathanael, E-mail: nathanael.lampe@gmail.com [Université de Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Bardiès, Manuel, E-mail: manuel.bardies@inserm.fr [CRCT, UMR 1037 INSERM, Université Paul Sabatier, F-31037 Toulouse (France); UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, F-31037 (France); Bordage, Marie-Claude, E-mail: marie-claude.bordage@inserm.fr [CRCT, UMR 1037 INSERM, Université Paul Sabatier, F-31037 Toulouse (France); UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, F-31037 (France)

    2017-05-01

    When low-energy electrons, such as Auger electrons, interact with liquid water, they induce highly localized ionizing energy depositions over ranges comparable to cell diameters. Monte Carlo track structure (MCTS) codes are suitable tools for performing dosimetry at this level. One of the main MCTS codes, Geant4-DNA, is equipped with only two sets of cross section models for low-energy electron interactions in liquid water (“option 2” and its improved version, “option 4”). To provide Geant4-DNA users with new alternative physics models, a set of cross sections, extracted from CPA100 MCTS code, have been added to Geant4-DNA. This new version is hereafter referred to as “Geant4-DNA-CPA100”. In this study, “Geant4-DNA-CPA100” was used to calculate low-energy electron dose-point kernels (DPKs) between 1 keV and 200 keV. Such kernels represent the radial energy deposited by an isotropic point source, a parameter that is useful for dosimetry calculations in nuclear medicine. In order to assess the influence of different physics models on DPK calculations, DPKs were calculated using the existing Geant4-DNA models (“option 2” and “option 4”), newly integrated CPA100 models, and the PENELOPE Monte Carlo code used in step-by-step mode for monoenergetic electrons. Additionally, a comparison was performed of two sets of DPKs that were simulated with “Geant4-DNA-CPA100” – the first set using Geant4′s default settings, and the second using CPA100′s original code default settings. A maximum difference of 9.4% was found between the Geant4-DNA-CPA100 and PENELOPE DPKs. Between the two Geant4-DNA existing models, slight differences, between 1 keV and 10 keV were observed. It was highlighted that the DPKs simulated with the two Geant4-DNA’s existing models were always broader than those generated with “Geant4-DNA-CPA100”. The discrepancies observed between the DPKs generated using Geant4-DNA’s existing models and “Geant4-DNA-CPA100” were

  1. R and D on the Geant4 radioactive decay physics

    Energy Technology Data Exchange (ETDEWEB)

    Hauf, Steffen; Kuster, Markus; Lang, Philipp M.; Hoffmann, Dieter H.H. [IKP, TU Darmstadt (Germany); Pia, Maria Grazia [CERN, Genf (Switzerland); INFN, Genua (Italy); Bell, Zane [Oak Ridge National Lab. (United States); Weidenspointner, Georg [MPI HLL, Muenchen (Germany); MPE, Garching (Germany); Zoglauer, Andreas [SSL, Berkeley (United States)

    2010-07-01

    The anticipated high sensitivity of the next generation X-ray space missions, like the International X-ray Observatory, rely on a low instrumental background, which in turn requires optimized shielding concepts for the instruments. Most state-of-the-art approaches estimate the prompt cosmic ray, solar proton and the cosmic X-ray induced background with simulations using the Geant4 Monte Carlo tool-kit whose electromagnetic and hadronic physics models have extensively been verified with space and ground based experiments. In contrast measurements to verify the radioactive decay implementation in Geant4 have been rare or have only been tested on a limited set of isotopes, which are not necessarily those used in satellite construction. We present first results of two experiments aimed to verify Geant4 activation and decay physics for materials significant for low background X-ray detectors in space.

  2. GEANT4: simulation for the next generation of HEP experiments

    International Nuclear Information System (INIS)

    Simone, Giani

    1996-01-01

    GEANT4 (RD44) is a world-wide collaboration of scientists aiming to create the detector simulation tool kit necessary for the next generation of HEP experiments. A large variety of requirements also come from heavy ions physics, CP violation physics, cosmic rays physics, medical applications and space science applications. In order to meet such requirements, a large degree of functionality and flexibility has to provided. GEANT4 is exploiting Object Oriented Technology to achieve these goals. The most relevant Object Oriented methodologies have been studied and a large number of tools and libraries have been investigated and evaluated. An overview of the GEANT4 analysis and design model will be given and the main components of the object models discussed. The main functionality of a first prototype will also be described. An overall view of the collaboration's structure and strategy will also be given. (author)

  3. Object-oriented approach to preequilibrium and equilibrium decays in Geant4

    International Nuclear Information System (INIS)

    Lara, V.

    2001-01-01

    The Geant4 simulation toolkit provides a set of parameterized models that allow to model hadronic showers. However, in order to allow extrapolation beyond the experimental data and to offer an alternative set of models at conventional energies, Geant4 also provides a set of theory based hadronic shower models. We present the Object Oriented Design of a semiclassical exciton model for preequilibrium decays and a set of statistical models for deexcitation of compound nuclei. Our design follows the philosophy of hadronic models in Geant4, allowing for maximum of extendibility and customizability of the underlying physics by means of the use of abstract interfaces. We exploit advanced Software Engineering techniques and Object Oriented technology to achieve those goals. We present also a series of comparisons against experimental data being made in order to test the model. (orig.)

  4. Software aspects of the Geant4 validation repository

    Science.gov (United States)

    Dotti, Andrea; Wenzel, Hans; Elvira, Daniel; Genser, Krzysztof; Yarba, Julia; Carminati, Federico; Folger, Gunter; Konstantinov, Dmitri; Pokorski, Witold; Ribon, Alberto

    2017-10-01

    The Geant4, GeantV and GENIE collaborations regularly perform validation and regression tests for simulation results. DoSSiER (Database of Scientific Simulation and Experimental Results) is being developed as a central repository to store the simulation results as well as the experimental data used for validation. DoSSiER is easily accessible via a web application. In addition, a web service allows for programmatic access to the repository to extract records in JSON or XML exchange formats. In this article, we describe the functionality and the current status of various components of DoSSiER as well as the technology choices we made.

  5. Software Aspects of the Geant4 Validation Repository

    CERN Document Server

    Dotti, Andrea; Elvira, Daniel; Genser, Krzysztof; Yarba, Julia; Carminati, Federico; Folger, Gunter; Konstantinov, Dmitri; Pokorski, Witold; Ribon, Alberto

    2016-01-01

    The Geant4, GeantV and GENIE collaborations regularly perform validation and regression tests for simulation results. DoSSiER (Database of Scientic Simulation and Experimental Results) is being developed as a central repository to store the simulation results as well as the experimental data used for validation. DoSSiER is easily accessible via a web application. In addition, a web service allows for programmatic access to the repository to extract records in JSON or XML exchange formats. In this article, we describe the functionality and the current status of various components of DoSSiER as well as the technology choices we made.

  6. G4-STORK: A Geant4-based Monte Carlo reactor kinetics simulation code

    International Nuclear Information System (INIS)

    Russell, Liam; Buijs, Adriaan; Jonkmans, Guy

    2014-01-01

    Highlights: • G4-STORK is a new, time-dependent, Monte Carlo code for reactor physics applications. • G4-STORK was built by adapting and expanding on the Geant4 Monte Carlo toolkit. • G4-STORK was designed to simulate short-term fluctuations in reactor cores. • G4-STORK is well suited for simulating sub- and supercritical assemblies. • G4-STORK was verified through comparisons with DRAGON and MCNP. - Abstract: In this paper we introduce G4-STORK (Geant4 STOchastic Reactor Kinetics), a new, time-dependent, Monte Carlo particle tracking code for reactor physics applications. G4-STORK was built by adapting and expanding on the Geant4 Monte Carlo toolkit. The toolkit provides the fundamental physics models and particle tracking algorithms that track each particle in space and time. It is a framework for further development (e.g. for projects such as G4-STORK). G4-STORK derives reactor physics parameters (e.g. k eff ) from the continuous evolution of a population of neutrons in space and time in the given simulation geometry. In this paper we detail the major additions to the Geant4 toolkit that were necessary to create G4-STORK. These include a renormalization process that maintains a manageable number of neutrons in the simulation even in very sub- or supercritical systems, scoring processes (e.g. recording fission locations, total neutrons produced and lost, etc.) that allow G4-STORK to calculate the reactor physics parameters, and dynamic simulation geometries that can change over the course of simulation to illicit reactor kinetics responses (e.g. fuel temperature reactivity feedback). The additions are verified through simple simulations and code-to-code comparisons with established reactor physics codes such as DRAGON and MCNP. Additionally, G4-STORK was developed to run a single simulation in parallel over many processors using MPI (Message Passing Interface) pipes

  7. GEANT 4.8.2, 9.2 and 9.4 simulations versus experimental proton energy loss in thick absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Evseev, Ivan; Schelin, Hugo R.; Ahmann, Francielle; Milhoretto, Edney; Paschuk, Sergei A., E-mail: evseev@utfpr.edu.b, E-mail: schelin@utfpr.edu.b, E-mail: sergei@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Yevseyeva, Olga; Assis, Joaquim T. de; Ievsieieva, Ievgeniia, E-mail: yevseveva@iprj.uerj.b, E-mail: joaquim@iprj.uerj.b [Instituto Politecnico do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil). Dept. de Modelagem Computacional; Hormaza, Joel M., E-mail: jmesa@ibb.unesp.b [Universidade Estadual Paulista (IBB/UNESP), Botucatu, SP (Brazil). Inst. de Biociencias; Diaz, Katherin S. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear, Havana (Cuba); Lopes, Ricardo T. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LIN/COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

    2011-07-01

    Monte Carlo simulations are a powerful tool to estimate the proton energy loss and straggling in medical applications. The physics of proton interaction with matter for thick absorbers (like a human body) has a well-established theory for the so-called Bethe-Bloch domain, and the basic principles of Monte Carlo simulation for such processes are well known since the middle of the past century. However, in spite of GEANT4 has been validated against proton stopping powers from the NIST PSTAR, the evolution of the code leads to some result instability within the various code releases. In this work, we present the recent results for the comparison of our GEANT4 simulations against experimental proton energy loss for some thick absorbers. All the simulations were performed using the GEANT4 Hadrontherapy Advanced Example. The GEANT4 versions 4.8.2, 4.9.2, and 4.9.4 were tested with different simulation parameters, such as varied cut values. In addition to the Standard model, some other models for the electromagnetic processes from the GEANT4 Low Energy Extension Pack were tested as well. Experimental data were taken from for polyethylene, and from for aluminum and gold absorbers. The theoretical predictions for the spectra were calculated using the self-consistent Gaussian solution of the Boltzmann kinetic equation in the Fokker-Plank form. In order to compare the GEANT4 simulations with other popular codes, the same spectra were simulated by TRIM/SRIM2011 and MCNPX2.4.0. The simultaneous comparison of the results obtained for different materials at various initial proton energies were done using the reduced calibration curve approach. (author)

  8. Optimization of GEANT4 settings for Proton Pencil Beam Scanning simulations using GATE

    Energy Technology Data Exchange (ETDEWEB)

    Grevillot, Loic, E-mail: loic.grevillot@gmail.co [Universite de Lyon, F-69622 Lyon (France); Creatis, CNRS UMR 5220, F-69622 Villeurbanne (France); Centre de Lutte Contre le Cancer Leon Berard, F-69373 Lyon (France); IBA, B-1348 Louvain-la-Neuve (Belgium); Frisson, Thibault [Universite de Lyon, F-69622 Lyon (France); Creatis, CNRS UMR 5220, F-69622 Villeurbanne (France); Centre de Lutte Contre le Cancer Leon Berard, F-69373 Lyon (France); Zahra, Nabil [Universite de Lyon, F-69622 Lyon (France); IPNL, CNRS UMR 5822, F-69622 Villeurbanne (France); Centre de Lutte Contre le Cancer Leon Berard, F-69373 Lyon (France); Bertrand, Damien; Stichelbaut, Frederic [IBA, B-1348 Louvain-la-Neuve (Belgium); Freud, Nicolas [Universite de Lyon, F-69622 Lyon (France); CNDRI, INSA-Lyon, F-69621 Villeurbanne Cedex (France); Sarrut, David [Universite de Lyon, F-69622 Lyon (France); Creatis, CNRS UMR 5220, F-69622 Villeurbanne (France); Centre de Lutte Contre le Cancer Leon Berard, F-69373 Lyon (France)

    2010-10-15

    This study reports the investigation of different GEANT4 settings for proton therapy applications in the context of Treatment Planning System comparisons. The GEANT4.9.2 release was used through the GATE platform. We focused on the Pencil Beam Scanning delivery technique, which allows for intensity modulated proton therapy applications. The most relevant options and parameters (range cut, step size, database binning) for the simulation that influence the dose deposition were investigated, in order to determine a robust, accurate and efficient simulation environment. In this perspective, simulations of depth-dose profiles and transverse profiles at different depths and energies between 100 and 230 MeV have been assessed against reference measurements in water and PMMA. These measurements were performed in Essen, Germany, with the IBA dedicated Pencil Beam Scanning system, using Bragg-peak chambers and radiochromic films. GEANT4 simulations were also compared to the PHITS.2.14 and MCNPX.2.5.0 Monte Carlo codes. Depth-dose simulations reached 0.3 mm range accuracy compared to NIST CSDA ranges, with a dose agreement of about 1% over a set of five different energies. The transverse profiles simulated using the different Monte Carlo codes showed discrepancies, with up to 15% difference in beam widening between GEANT4 and MCNPX in water. A 8% difference between the GEANT4 multiple scattering and single scattering algorithms was observed. The simulations showed the inability of reproducing the measured transverse dose spreading with depth in PMMA, corroborating the fact that GEANT4 underestimates the lateral dose spreading. GATE was found to be a very convenient simulation environment to perform this study. A reference physics-list and an optimized parameters-list have been proposed. Satisfactory agreement against depth-dose profiles measurements was obtained. The simulation of transverse profiles using different Monte Carlo codes showed significant deviations. This point

  9. CAD-based automatic modeling method for Geant4 geometry model through MCAM

    International Nuclear Information System (INIS)

    Wang, D.; Nie, F.; Wang, G.; Long, P.; LV, Z.

    2013-01-01

    The full text of publication follows. Geant4 is a widely used Monte Carlo transport simulation package. Before calculating using Geant4, the calculation model need be established which could be described by using Geometry Description Markup Language (GDML) or C++ language. However, it is time-consuming and error-prone to manually describe the models by GDML. Automatic modeling methods have been developed recently, but there are some problems that exist in most present modeling programs, specially some of them were not accurate or adapted to specifically CAD format. To convert the GDML format models to CAD format accurately, a Geant4 Computer Aided Design (CAD) based modeling method was developed for automatically converting complex CAD geometry model into GDML geometry model. The essence of this method was dealing with CAD model represented with boundary representation (B-REP) and GDML model represented with constructive solid geometry (CSG). At first, CAD model was decomposed to several simple solids which had only one close shell. And then the simple solid was decomposed to convex shell set. Then corresponding GDML convex basic solids were generated by the boundary surfaces getting from the topological characteristic of a convex shell. After the generation of these solids, GDML model was accomplished with series boolean operations. This method was adopted in CAD/Image-based Automatic Modeling Program for Neutronics and Radiation Transport (MCAM), and tested with several models including the examples in Geant4 install package. The results showed that this method could convert standard CAD model accurately, and can be used for Geant4 automatic modeling. (authors)

  10. The study on the import of the geometric body by GDML in GEANT4

    International Nuclear Information System (INIS)

    Sun Baodong; Liu Huilan; Sun Dawang; Xie Zhaoyang; Song Yushou

    2014-01-01

    Geometry Description Markup Language (GDML) can be used as an application interface program to import the geometric body into GEANT4. It greatly simplifies the detector construction work with high reliability. With this mechanism the geometric data of a detector is described in an XML file and read by the XML parser embedded in GEANT4. The geometric structure of a detector is designed in CAD toolkit Solidworks and saved as a standard STEP file. Then, by FastRad the STEP file is transformed into XML script, which is readable for GEANT4. In comparison with the detectors constructed by Constructed Solid Geometry (CSG) provided by GEANT4, those imported by GDML also satisfies the requests of general simulation application. At the same time, some solutions and tips for several common problems during the progress constructing the detectors by GDML are given. (authors)

  11. SU-E-T-565: RAdiation Resistance of Cancer CElls Using GEANT4 DNA: RACE

    Energy Technology Data Exchange (ETDEWEB)

    Perrot, Y; Payno, H; Delage, E; Maigne, L [Clermont Universite, CNRS/IN2P3, Laboratoire de Physique Corpusculaire de Clermont-Ferrand, Aubiere (France); Incerti, S [Universite Bordeaux 1, CNRS/IN2P3, Centres d' Etudes Nucleaires de Bordeaux-Gradignan, Gradignan (France); Debiton, E; Peyrode, C; Chezal, J; Miot-Noirault, E; Degoul, F [Clermont Universite, Universite d' Auvergne, Imagerie Moleculaire et Therapie Vectorisee, INSERM U990, Centre Jean Perrin, Clermont-Ferrand (France)

    2014-06-01

    Purpose: The objective of the RACE project is to develop a comparison between Monte Carlo simulation using the Geant4-DNA toolkit and measurements of radiation damage on 3D melanoma and chondrosarcoma culture cells coupled with gadolinium nanoparticles. We currently expose the status of the developments regarding simulations. Methods: Monte Carlo studies are driven using the Geant4 toolkit and the Geant4-DNA extension. In order to model the geometry of a cell population, the opensource CPOP++ program is being developed for the geometrical representation of 3D cell populations including a specific cell mesh coupled with a multi-agent system. Each cell includes cytoplasm and nucleus. The correct modeling of the cell population has been validated with confocal microscopy images of spheroids. The Geant4 Livermore physics models are used to simulate the interactions of a 250 keV X-ray beam and the production of secondaries from gadolinium nanoparticles supposed to be fixed on the cell membranes. Geant4-DNA processes are used to simulate the interactions of charged particles with the cells. An atomistic description of the DNA molecule, from PDB (Protein Data Bank) files, is provided by the so-called PDB4DNA Geant4 user application we developed to score energy depositions in DNA base pairs and sugar-phosphate groups. Results: At the microscopic level, our simulations enable assessing microscopic energy distribution in each cell compartment of a realistic 3D cell population. Dose enhancement factors due to the presence of gadolinium nanoparticles can be estimated. At the nanometer scale, direct damages on nuclear DNA are also estimated. Conclusion: We successfully simulated the impact of direct radiations on a realistic 3D cell population model compatible with microdosimetry calculations using the Geant4-DNA toolkit. Upcoming validation and the future integration of the radiochemistry module of Geant4-DNA will propose to correlate clusters of ionizations with in vitro

  12. Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

    International Nuclear Information System (INIS)

    Gerlach, M.; Krumrey, M.; Cibik, L.; Mueller, P.; Ulm, G.

    2009-01-01

    Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

  13. Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

    Science.gov (United States)

    Gerlach, M.; Krumrey, M.; Cibik, L.; Müller, P.; Ulm, G.

    2009-09-01

    Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

  14. Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, M. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Krumrey, M. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)], E-mail: Michael.Krumrey@ptb.de; Cibik, L.; Mueller, P.; Ulm, G. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)

    2009-09-11

    Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

  15. Monte Carlo simulation of the electron transport through thin slabs: A comparative study of PENELOPE, GEANT3, GEANT4, EGSnrc and MCNPX

    Energy Technology Data Exchange (ETDEWEB)

    Vilches, M. [Servicio de Fisica y Proteccion Radiologica, Hospital Regional Universitario ' Virgen de las Nieves' , Avda. de las Fuerzas Armadas, 2, E-18014 Granada (Spain)]. E-mail: mvilches@ugr.es; Garcia-Pareja, S. [Servicio de Radiofisica Hospitalaria, Hospital Regional Universitario ' Carlos Haya' , Avda. Carlos Haya, s/n, E-29010 Malaga (Spain)]. E-mail: garciapareja@gmail.com; Guerrero, R. [Servicio de Radiofisica, Hospital Universitario ' San Cecilio' , Avda. Dr. Oloriz, 16, E-18012 Granada (Spain)]. E-mail: rafael.guerrero.alcalde.sspa@juntadeandalucia.es; Anguiano, M. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain)]. E-mail: mangui@ugr.es; Lallena, A.M. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain)]. E-mail: lallena@ugr.es

    2007-01-15

    The Monte Carlo simulation of the electron transport through thin slabs is studied with five general purpose codes: PENELOPE, GEANT3, GEANT4, EGSnrc and MCNPX. The different material foils analyzed in the old experiments of Kulchitsky and Latyshev [L.A. Kulchitsky, G.D. Latyshev, Phys. Rev. 61 (1942) 254] and Hanson et al. [A.O. Hanson, L.H. Lanzl, E.M. Lyman, M.B. Scott, Phys. Rev. 84 (1951) 634] are used to perform the comparison between the Monte Carlo codes. Non-negligible differences are observed in the angular distributions of the transmitted electrons obtained with the some of the codes. The experimental data are reasonably well described by EGSnrc, PENELOPE (v.2005) and GEANT4. A general good agreement is found for EGSnrc and PENELOPE (v.2005) in all the cases analyzed.

  16. Monte Carlo simulation of the electron transport through thin slabs: A comparative study of PENELOPE, GEANT3, GEANT4, EGSnrc and MCNPX

    International Nuclear Information System (INIS)

    Vilches, M.; Garcia-Pareja, S.; Guerrero, R.; Anguiano, M.; Lallena, A.M.

    2007-01-01

    The Monte Carlo simulation of the electron transport through thin slabs is studied with five general purpose codes: PENELOPE, GEANT3, GEANT4, EGSnrc and MCNPX. The different material foils analyzed in the old experiments of Kulchitsky and Latyshev [L.A. Kulchitsky, G.D. Latyshev, Phys. Rev. 61 (1942) 254] and Hanson et al. [A.O. Hanson, L.H. Lanzl, E.M. Lyman, M.B. Scott, Phys. Rev. 84 (1951) 634] are used to perform the comparison between the Monte Carlo codes. Non-negligible differences are observed in the angular distributions of the transmitted electrons obtained with the some of the codes. The experimental data are reasonably well described by EGSnrc, PENELOPE (v.2005) and GEANT4. A general good agreement is found for EGSnrc and PENELOPE (v.2005) in all the cases analyzed

  17. Use of GEANT4 vs. MCNPX for the characterization of a boron-lined neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Ende, B.M. van der; Atanackovic, J.; Erlandson, A.; Bentoumi, G.

    2016-06-01

    This work compares GEANT4 with MCNPX in the characterization of a boron-lined neutron detector. The neutron energy ranges simulated in this work (0.025 eV to 20 MeV) are the traditional domain of MCNP simulations. This paper addresses the question, how well can GEANT4 and MCNPX be employed for detailed thermal neutron detector characterization? To answer this, GEANT4 and MCNPX have been employed to simulate detector response to a {sup 252}Cf energy spectrum point source, as well as to simulate mono-energetic parallel beam source geometries. The {sup 252}Cf energy spectrum simulation results demonstrate agreement in detector count rate within 3% between the two packages, with the MCNPX results being generally closer to experiment than are those from GEANT4. The mono-energetic source simulations demonstrate agreement in detector response within 5% between the two packages for all neutron energies, and within 1% for neutron energies between 100 eV and 5 MeV. Cross-checks between the two types of simulations using ISO-8529 {sup 252}Cf energy bins demonstrates that MCNPX results are more self-consistent than are GEANT4 results, by 3–4%.

  18. Comparison of GEANT4 very low energy cross section models with experimental data in water

    DEFF Research Database (Denmark)

    Incerti, S; Ivanchenko, A; Karamitros, M

    2010-01-01

    The GEANT4 general-purpose Monte Carlo simulation toolkit is able to simulate physical interaction processes of electrons, hydrogen and helium atoms with charge states (H0, H+) and (He0, He+, He2+), respectively, in liquid water, the main component of biological systems, down to the electron volt...... of electromagnetic interactions within the GEANT4 toolkit framework (since GEANT4 version 9.3 beta). This work presents a quantitative comparison of these physics models with a collection of experimental data in water collected from the literature....

  19. Electro and gamma nuclear physics in Geant4

    CERN Document Server

    Wellisch, J P; Degtyarenko, P V

    2003-01-01

    Adequate description of electro and gamma nuclear physics is of utmost importance in studies of electron beam-dumps and intense electron beam accelerators. I also is mandatory to describe neutron backgrounds and activation in linear colliders. This physics was elaborated in Geant4 over the last year, and now entered into the stage of practical application. In the {\\sc Geant4} Photo-nuclear data base there are at present about 50 nuclei for which the Photo-nuclear absorption cross sections have been measured. Of these, data on 14 nuclei are used to parametrize the gamma nuclear reaction cross-section The resulting cross section is a complex, factorized function of $A$ and $e = log(E_\\gamma)$, where $E_\\gamma$ is the energy of the incident photon. Electro-nuclear reactions are so closely connected with Photo-nuclear reactions that sometimes they are often called ``Photo-nuclear''. The one-photon exchange mechanism dominates in Electro-nuclear reactions, and the electron can be substituted by a flux of photons. ...

  20. Setup of HDRK-Man voxel model in Geant4 Monte Carlo code

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jong Hwi; Cho, Sung Koo; Kim, Chan Hyeong [Hanyang Univ., Seoul (Korea, Republic of); Choi, Sang Hyoun [Inha Univ., Incheon (Korea, Republic of); Cho, Kun Woo [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2008-10-15

    Many different voxel models, developed using tomographic images of human body, are used in various fields including both ionizing and non-ionizing radiation fields. Recently a high-quality voxel model/ named HDRK-Man, was constructed at Hanyang University and used to calculate the dose conversion coefficients (DCC) values for external photon and neutron beams using the MCNPX Monte Carlo code. The objective of the present study is to set up the HDRK-Man model in Geant4 in order to use it in more advanced calculations such as 4-D Monte Carlo simulations and space dosimetry studies involving very high energy particles. To that end, the HDRK-Man was ported to Geant4 and used to calculate the DCC values for external photon beams. The calculated values were then compared with the results of the MCNPX code. In addition, a computational Linux cluster was built to improve the computing speed in Geant4.

  1. artG4: A Generic Framework for Geant4 Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Arvanitis, Tasha [Harvey Mudd Coll.; Lyon, Adam [Fermilab

    2014-01-01

    A small experiment must devote its limited computing expertise to writing physics code directly applicable to the experiment. A software 'framework' is essential for providing an infrastructure that makes writing the physics-relevant code easy. In this paper, we describe a highly modular and easy to use framework for writing Geant4 based simulations called 'artg4'. This framework is a layer on top of the art framework.

  2. GEANT4 simulations for Proton computed tomography applications

    International Nuclear Information System (INIS)

    Yevseyeva, Olga; Assis, Joaquim T. de; Evseev, Ivan; Schelin, Hugo R.; Shtejer Diaz, Katherin; Lopes, Ricardo T.

    2011-01-01

    Proton radiation therapy is a highly precise form of cancer treatment. In existing proton treatment centers, dose calculations are performed based on X-ray computed tomography (CT). Alternatively, one could image the tumor directly with proton CT (pCT). Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. The spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through gold absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadron therapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development. The authors want to thank CNPq, CAPES and 'Fundacao Araucaria' for financial support of this work. (Author)

  3. An algorithm for computing screened Coulomb scattering in GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Mendenhall, Marcus H. [Vanderbilt University Free Electron Laser Center, P.O. Box 351816 Station B, Nashville, TN 37235-1816 (United States)]. E-mail: marcus.h.mendenhall@vanderbilt.edu; Weller, Robert A. [Department of Electrical Engineering and Computer Science, Vanderbilt University, P.O. Box 351821 Station B, Nashville, TN 37235-1821 (United States)]. E-mail: robert.a.weller@vanderbilt.edu

    2005-01-01

    An algorithm has been developed for the GEANT4 Monte-Carlo package for the efficient computation of screened Coulomb interatomic scattering. It explicitly integrates the classical equations of motion for scattering events, resulting in precise tracking of both the projectile and the recoil target nucleus. The algorithm permits the user to plug in an arbitrary screening function, such as Lens-Jensen screening, which is good for backscattering calculations, or Ziegler-Biersack-Littmark screening, which is good for nuclear straggling and implantation problems. This will allow many of the applications of the TRIM and SRIM codes to be extended into the much more general GEANT4 framework where nuclear and other effects can be included.

  4. An algorithm for computing screened Coulomb scattering in GEANT4

    International Nuclear Information System (INIS)

    Mendenhall, Marcus H.; Weller, Robert A.

    2005-01-01

    An algorithm has been developed for the GEANT4 Monte-Carlo package for the efficient computation of screened Coulomb interatomic scattering. It explicitly integrates the classical equations of motion for scattering events, resulting in precise tracking of both the projectile and the recoil target nucleus. The algorithm permits the user to plug in an arbitrary screening function, such as Lens-Jensen screening, which is good for backscattering calculations, or Ziegler-Biersack-Littmark screening, which is good for nuclear straggling and implantation problems. This will allow many of the applications of the TRIM and SRIM codes to be extended into the much more general GEANT4 framework where nuclear and other effects can be included

  5. Estimated Visualization of Dose Calculation with GEANT4 in Medical Linac

    International Nuclear Information System (INIS)

    Kim, Jhin Kee; Kim, Bu Gil; Lee, Jeong Ok; Kang, Jeong Ku; Oh, Young Kee; Jeong, Dong Hyeok; Kim, Jeong Kee

    2011-01-01

    Geant4 is a toolkit used to simulate the pass age of particles through matter. Recently, it has been used in many medical physics applications. In radiotherapy, positron emission tomography, and magnetic resonance tomography, Geant4 has been applied to accurately simulate the propagation of particles and the interaction of particles, not only with medical devices, but also with patient's phantoms.1,2 Many researchers try to use patient's image data to calculate the dose. The use of DICOM images files to simulate is desired. We construct detector with parameterized volume for Geant4 simulations, which can be applied to simulations using DICOM data as the input.We try to apply this code to the patient's DICOM images to simulate the propagation and interaction of the particles. So we can calculate the absorbed dose of the patient. In this study, the used visualization tool is called gMocren. The purpose of the present paper is to verify a volume visualization tool that simultaneously displays both the complex patient data and the simulated dose distribution with real patient's DICOM data. We applied a volume visualization tool for GEANT4 simulation. We developed to create the each voxel's dose tables of the every slices and review the distribution with DICOM file, gMocren is very convenience tool but provide only qualitative analysis. We need more enhanced functions to display contour like RTP and utility program to create dose table in every points.

  6. Comparison of CdZnTe neutron detector models using MCNP6 and Geant4

    Science.gov (United States)

    Wilson, Emma; Anderson, Mike; Prendergasty, David; Cheneler, David

    2018-01-01

    The production of accurate detector models is of high importance in the development and use of detectors. Initially, MCNP and Geant were developed to specialise in neutral particle models and accelerator models, respectively; there is now a greater overlap of the capabilities of both, and it is therefore useful to produce comparative models to evaluate detector characteristics. In a collaboration between Lancaster University, UK, and Innovative Physics Ltd., UK, models have been developed in both MCNP6 and Geant4 of Cadmium Zinc Telluride (CdZnTe) detectors developed by Innovative Physics Ltd. Herein, a comparison is made of the relative strengths of MCNP6 and Geant4 for modelling neutron flux and secondary γ-ray emission. Given the increasing overlap of the modelling capabilities of MCNP6 and Geant4, it is worthwhile to comment on differences in results for simulations which have similarities in terms of geometries and source configurations.

  7. How to create an interface between UrQMD and Geant4 toolkit

    CERN Document Server

    Abdel-Waged, Khaled; Uzhinskii, V.V.

    2012-01-01

    An interface between the UrQMD-1.3cr model (version 1.3 for cosmic air showers) and the Geant4 transport toolkit has been developed. Compared to the current Geant4 (hybrid) hadronic models, this provides the ability to simulate at the microscopic level hadron, nucleus, and anti-nucleus interactions with matter from 0 to 1 TeV with a single transport code. This document provides installation requirements and instructions, as well as class and member function descriptions of the software.

  8. Preliminary assessment of Geant4 HP models and cross section libraries by reactor criticality benchmark calculations

    DEFF Research Database (Denmark)

    Cai, Xiao-Xiao; Llamas-Jansa, Isabel; Mullet, Steven

    2013-01-01

    Geant4 is an open source general purpose simulation toolkit for particle transportation in matter. Since the extension of the thermal scattering model in Geant4.9.5 and the availability of the IAEA HP model cross section libraries, it is now possible to extend the application area of Geant4......, U and O in uranium dioxide, Al metal, Be metal, and Fe metal. The native HP cross section library G4NDL does not include data for elements with atomic number larger than 92. Therefore, transuranic elements, which have impacts for a realistic reactor, can not be simulated by the combination of the HP...... models and the G4NDL library. However, cross sections of those missing isotopes were made available recently through the IAEA project “new evaluated neutron cross section libraries for Geant4”....

  9. Diffusion-controlled reactions modeling in Geant4-DNA

    Czech Academy of Sciences Publication Activity Database

    Karamitros, M.; Luan, S.; Bernal, M. A.; Allison, J.; Baldacchino, G.; Davídková, Marie; Francis, Z.; Friedland, W.; Ivanchenko, A.; Ivanchenko, V.; Mantero, A.; Nieminen, P.; Santin, G.; Tran, H. N.; Stepan, V.; Incerti, S.

    2014-01-01

    Roč. 274, OCT (2014), s. 841-882 ISSN 0021-9991 Institutional support: RVO:61389005 Keywords : chemical kinetics simulation * radiation chemistry * Fokker-Planck equation * Smoluchowski diffusion equation * Brownian bridge * dynamical time steps * k-d tree * radiolysis * radiobiology * Geant4-DNA * Brownian dynamics Subject RIV: BO - Biophysics Impact factor: 2.434, year: 2014

  10. Simulating response functions and pulse shape discrimination for organic scintillation detectors with Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, Zachary S., E-mail: hartwig@psfc.mit.edu [Department of Nuclear Science and Engineering, MIT, Cambridge MA (United States); Gumplinger, Peter [TRIUMF, Vancouver, BC (Canada)

    2014-02-11

    We present new capabilities of the Geant4 toolkit that enable the precision simulation of organic scintillation detectors within a comprehensive Monte Carlo code for the first time. As of version 10.0-beta, the Geant4 toolkit models the data-driven photon production from any user-defined scintillator, photon transportation through arbitrarily complex detector geometries, and time-resolved photon detection at the light readout device. By fully specifying the optical properties and geometrical configuration of the detector, the user can simulate response functions, photon transit times, and pulse shape discrimination. These capabilities enable detector simulation within a larger experimental environment as well as computationally evaluating novel scintillators, detector geometry, and light readout configurations. We demonstrate agreement of Geant4 with the NRESP7 code and with experiments for the spectroscopy of neutrons and gammas in the ranges 0–20 MeV and 0.511–1.274 MeV, respectively, using EJ301-based organic scintillation detectors. We also show agreement between Geant4 and experimental modeling of the particle-dependent detector pulses that enable simulated pulse shape discrimination. -- Highlights: • New capabilities enable the modeling of organic scintillation detectors in Geant4. • Detector modeling of complex scintillators, geometries, and light readout. • Enables particle- and energy-dependent production of scintillation photons. • Provides ability to generate response functions with precise optical physics. • Provides ability to computationally evaluate pulse shape discrimination.

  11. PDB4DNA: Implementation of DNA geometry from the Protein Data Bank (PDB) description for Geant4-DNA Monte-Carlo simulations

    Science.gov (United States)

    Delage, E.; Pham, Q. T.; Karamitros, M.; Payno, H.; Stepan, V.; Incerti, S.; Maigne, L.; Perrot, Y.

    2015-07-01

    This paper describes PDB4DNA, a new Geant4 user application, based on an independent, cross-platform, free and open source C++ library, so-called PDBlib, which enables use of atomic level description of DNA molecule in Geant4 Monte Carlo particle transport simulations. For the evaluation of direct damage induced on the DNA molecule by ionizing particles, the application makes use of an algorithm able to determine the closest atom in the DNA molecule to energy depositions. Both the PDB4DNA application and the PDBlib library are available as free and open source under the Geant4 license.

  12. A Customizable GeantV Calorimeter Application

    CERN Document Server

    Schmitz, Ryan; Vallecorsa, Sofia; Novak, Mihaly; CERN. Geneva. EP Department

    2017-01-01

    A customizable calorimeter application was written in GeantV. This application includes a GeantV-native detector construction file as well as GeantV-native physics models and new data collection structures. Including these features makes this one of the first examples of a completely standalone GeantV application. A comparison to Geant4 was made which showed the consistency of the GeantV-native physics models included in this example. Finally, the workflow improvements made by the creation of this application are described.

  13. The Inner Detector software moves to Geant4

    CERN Multimedia

    Elsing, M

    2004-01-01

    2004 is a year of change and of several major milestones for the Inner Detector software. The first of these milestones was met in March when a set of test events was successfully processed through Geant4 and afterwards through the full Inner Detector offline software chain. In the picture, a reconstructed single muon event from this test sample is displayed in different projections. Even though this looks almost trivial, it required the successful integration of several new software components besides Geant4 into the Inner Detector code. A new ATLAS wide Detector Description software package called GeoModel has been fully deployed in the Inner Detector as the single source of geometry information for both the simulation and the reconstruction. New code to emulate the digitization for all detectors and a new data model have been put in place to cope with the new simulation input. And finally the two major offline reconstruction packages, namely xKalman and iPatRec, were migrated to use the new Inner Detector ...

  14. GAMOS: A framework to do GEANT4 simulations in different physics fields with an user-friendly interface

    International Nuclear Information System (INIS)

    Arce, Pedro; Ignacio Lagares, Juan; Harkness, Laura; Pérez-Astudillo, Daniel; Cañadas, Mario; Rato, Pedro; Prado, María de; Abreu, Yamiel; Lorenzo, Gianluca de; Kolstein, Machiel; Díaz, Angelina

    2014-01-01

    GAMOS is a software system for GEANT4-based simulation. It comprises a framework, a set of components providing functionality to simulation applications on top of the GEANT4 toolkit, and a collection of ready-made applications. It allows to perform GEANT4-based simulations using a scripting language, without requiring the writing of C++ code. Moreover, GAMOS design allows the extension of the existing functionality through user-supplied C++ classes. The main characteristics of GAMOS and its embedded functionality are described

  15. Geant4 Developments for the Radon Electric Dipole Moment Search at TRIUMF

    Science.gov (United States)

    Rand, E. T.; Bangay, J. C.; Bianco, L.; Dunlop, R.; Finlay, P.; Garrett, P. E.; Leach, K. G.; Phillips, A. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Wong, J.

    2011-09-01

    An experiment is being developed at TRIUMF to search for a time-reversal violating electric dipole moment (EDM) in odd-A isotopes of Rn. Extensive simulations of the experiment are being performed with GEANT4 to study the backgrounds and sensitivity of the proposed measurement technique involving the detection of γ rays emitted following the β decay of polarized Rn nuclei. GEANT4 developments for the RnEDM experiment include both realistic modelling of the detector geometry and full tracking of the radioactive β, γ, internal conversion, and x-ray processes, including the γ-ray angular distributions essential for measuring an atomic EDM.

  16. Validation of recent Geant4 physics models for application in carbon ion therapy

    CERN Document Server

    Lechner, A; Ivanchenko, V N

    2010-01-01

    Cancer treatment with energetic carbon ions has distinct advantages over proton or photon irradiation. In this paper we present a simulation model integrated into the Geant4 Monte Carlo toolkit (version 9.3) which enables the use of ICRU 73 stopping powers for ion transport calculations. For a few materials, revised ICRU 73 stopping power tables recently published by ICRU (P. Sigmund, A. Schinner, H. Paul, Errata and Addenda: ICRU Report 73 (Stopping of Ions Heavier than Helium), International Commission on Radiation Units and Measurements, 2009) were incorporated into Geant4, also covering media like water which are of importance in radiotherapeutical applications. We examine, with particular attention paid to the recent developments, the accuracy of current Geant4 models for simulating Bragg peak profiles of C-12 ions incident on water and polyethylene targets. Simulated dose distributions are validated against experimental data available in the literature, where the focus is on beam energies relevant to io...

  17. Research in Geant4 electromagnetic physics design, and its effects on computational performance and quality assurance

    CERN Document Server

    Augelli, M; Hauf, S; Kim, C H; Kuster, M; Pia, M G; Filho, P Queiroz; Quintieri, L; Saracco, P; Santos, D Souza; Weidenspointner, G; Zoglauer, A

    2009-01-01

    The Geant4 toolkit offers a rich variety of electromagnetic physics models; so far the evaluation of this Geant4 domain has been mostly focused on its physics functionality, while the features of its design and their impact on simulation accuracy, computational performance and facilities for verification and validation have not been the object of comparable attention yet, despite the critical role they play in many experimental applications. A new project is in progress to study the application of new design concepts and software techniques in Geant4 electromagnetic physics, and to evaluate how they can improve on the current simulation capabilities. The application of a policy-based class design is investigated as a means to achieve the objective of granular decomposition of processes; this design technique offers various advantages in terms of flexibility of configuration and computational performance. The current Geant4 physics models have been re-implemented according to the new design as a pilot project....

  18. Microdosimetry calculations for monoenergetic electrons using Geant4-DNA combined with a weighted track sampling algorithm.

    Science.gov (United States)

    Famulari, Gabriel; Pater, Piotr; Enger, Shirin A

    2017-07-07

    The aim of this study was to calculate microdosimetric distributions for low energy electrons simulated using the Monte Carlo track structure code Geant4-DNA. Tracks for monoenergetic electrons with kinetic energies ranging from 100 eV to 1 MeV were simulated in an infinite spherical water phantom using the Geant4-DNA extension included in Geant4 toolkit version 10.2 (patch 02). The microdosimetric distributions were obtained through random sampling of transfer points and overlaying scoring volumes within the associated volume of the tracks. Relative frequency distributions of energy deposition f(>E)/f(>0) and dose mean lineal energy ([Formula: see text]) values were calculated in nanometer-sized spherical and cylindrical targets. The effects of scoring volume and scoring techniques were examined. The results were compared with published data generated using MOCA8B and KURBUC. Geant4-DNA produces a lower frequency of higher energy deposits than MOCA8B. The [Formula: see text] values calculated with Geant4-DNA are smaller than those calculated using MOCA8B and KURBUC. The differences are mainly due to the lower ionization and excitation cross sections of Geant4-DNA for low energy electrons. To a lesser extent, discrepancies can also be attributed to the implementation in this study of a new and fast scoring technique that differs from that used in previous studies. For the same mean chord length ([Formula: see text]), the [Formula: see text] calculated in cylindrical volumes are larger than those calculated in spherical volumes. The discrepancies due to cross sections and scoring geometries increase with decreasing scoring site dimensions. A new set of [Formula: see text] values has been presented for monoenergetic electrons using a fast track sampling algorithm and the most recent physics models implemented in Geant4-DNA. This dataset can be combined with primary electron spectra to predict the radiation quality of photon and electron beams.

  19. A Student Project to use Geant4 Simulations for a TMS-PET combination

    International Nuclear Information System (INIS)

    Altamirano, A.; Chamorro, A.; Hurtado, K.; Romero, C.; Wahl, D.; Zamudio, A.; Rueda, A.; Solano Salinas, C. J.

    2007-01-01

    Geant4 is one of the most powerful tools for MC simulation of detectors and their applications. We present a student project to simulate a combined Transcranial Magnetic Stimulation-Positron Emission Tomography (TMS-PET) system using Geant4. This project aims to study PET-TMS systems by implementing a model for the brain response to the TMS pulse and studying the simulated PET response. In order to increase the speed of the simulations we parallelise our programs and investigate the possibility of using GRID computing

  20. A Student Project to use Geant4 Simulations for a TMS-PET combination

    Science.gov (United States)

    Altamirano, A.; Chamorro, A.; Hurtado, K.; Romero, C.; Rueda, A.; Solano Salinas, C. J.; Wahl, D.; Zamudio, A.

    2007-10-01

    Geant4 is one of the most powerful tools for MC simulation of detectors and their applications. We present a student project to simulate a combined Transcranial Magnetic Stimulation-Positron Emission Tomography (TMS-PET) system using Geant4. This project aims to study PET-TMS systems by implementing a model for the brain response to the TMS pulse and studying the simulated PET response. In order to increase the speed of the simulations we parallelise our programs and investigate the possibility of using GRID computing.

  1. Implementation of mathematical phantom of hand and forearm in GEANT4 Monte Carlo code

    International Nuclear Information System (INIS)

    Pessanha, Paula Rocha; Queiroz Filho, Pedro Pacheco de; Santos, Denison de Souza

    2014-01-01

    In this work, the implementation of a hand and forearm Geant4 phantom code, for further evaluation of occupational exposure of ends of the radionuclides decay manipulated during procedures involving the use of injection syringe. The simulation model offered by Geant4 includes a full set of features, with the reconstruction of trajectories, geometries and physical models. For this work, the values calculated in the simulation are compared with the measurements rates by thermoluminescent dosimeters (TLDs) in physical phantom REMAB®. From the analysis of the data obtained through simulation and experimentation, of the 14 points studied, there was a discrepancy of only 8.2% of kerma values found, and these figures are considered compatible. The geometric phantom implemented in Geant4 Monte Carlo code was validated and can be used later for the evaluation of doses at ends

  2. Molecular scale track structure simulations in liquid water using the Geant4-DNA Monte-Carlo processes

    Czech Academy of Sciences Publication Activity Database

    Francis, Z.; Incerti, S.; Capra, R.; Mascialino, B.; Montarou, G.; Štěpán, Václav; Villagrasa, C.

    2011-01-01

    Roč. 69, č. 1 (2011), s. 220-226 ISSN 0969-8043 R&D Projects: GA MŠk OC09012 Institutional research plan: CEZ:AV0Z10480505 Keywords : Monte Carlo * Geant4 * Geant4 DNA * microdosimetry * cross sections Subject RIV: BO - Biophysics Impact factor: 1.172, year: 2011

  3. Track structure modeling in liquid water: A review of the Geant4-DNA very low energy extension of the Geant4 Monte Carlo simulation toolkit

    Czech Academy of Sciences Publication Activity Database

    Bernal, M. A.; Bordage, M. C.; Brown, J. M. C.; Davídková, Marie; Delage, E.; El Bitar, Z.; Enger, S. A.; Francis, Z.; Guatelli, S.; Ivanchenko, V.; Karamitros, M.; Kyriakou, I.; Maigne, L.; Meylan, S.; Murakami, K.; Okada, S.; Payno, H.; Perrot, Y.; Petrovic, I.; Pham, Q. T.; Ristic-Fira, A.; Sasaki, T.; Štěpán, Václav; Tran, H. N.; Villagrasa, C.; Incerti, S.

    2015-01-01

    Roč. 31, č. 8 (2015), s. 861-874 ISSN 1120-1797 Institutional support: RVO:61389005 Keywords : Monte Carlo * Geant4-DNA * radiolysis * radiobiology * ionizing radiation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.763, year: 2015

  4. Monte Carlo calculations of thermal neutron capture in gadolinium: a comparison of GEANT4 and MCNP with measurements.

    Science.gov (United States)

    Enger, Shirin A; Munck af Rosenschöld, Per; Rezaei, Arash; Lundqvist, Hans

    2006-02-01

    GEANT4 is a Monte Carlo code originally implemented for high-energy physics applications and is well known for particle transport at high energies. The capacity of GEANT4 to simulate neutron transport in the thermal energy region is not equally well known. The aim of this article is to compare MCNP, a code commonly used in low energy neutron transport calculations and GEANT4 with experimental results and select the suitable code for gadolinium neutron capture applications. To account for the thermal neutron scattering from chemically bound atoms [S(alpha,beta)] in biological materials a comparison of thermal neutron fluence in tissue-like poly(methylmethacrylate) phantom is made with MCNP4B, GEANT4 6.0 patch1, and measurements from the neutron capture therapy (NCT) facility at the Studsvik, Sweden. The fluence measurements agreed with MCNP calculated results considering S(alpha,beta). The location of the thermal neutron peak calculated with MCNP without S(alpha,beta) and GEANT4 is shifted by about 0.5 cm towards a shallower depth and is 25%-30% lower in amplitude. Dose distribution from the gadolinium neutron capture reaction is then simulated by MCNP and compared with measured data. The simulations made by MCNP agree well with experimental results. As long as thermal neutron scattering from chemically bound atoms are not included in GEANT4 it is not suitable for NCT applications.

  5. Comparison of GEANT4 Simulations with Experimental Data for Thick Al Absorbers

    International Nuclear Information System (INIS)

    Yevseyeva, Olga; Assis, Joaquim de; Evseev, Ivan; Schelin, Hugo; Paschuk, Sergei; Milhoretto, Edney; Setti, Joao; Diaz, Katherin; Lopes, Ricardo; Hormaza, Joel

    2009-01-01

    Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Therefore, relatively small differences in the total proton stopping power given, for example, by the different models provided by GEANT4 can lead to significant disagreements in the final proton energy spectra when integrated along lengthy proton trajectories. This work presents proton energy spectra obtained by GEANT4.8.2 simulations using ICRU49, Ziegler1985 and Ziegler2000 models for 19.68 MeV protons passing through a number of Al absorbers with various thicknesses. The spectra were compared with the experimental data, with TRIM/SRIM2008 and MCNPX2.4.0 simulations, and with the Payne analytical solution for the transport equation in the Fokker-Plank approximation. It is shown that the MCNPX simulations reasonably reproduce well all experimental spectra. For the relatively thin targets all the methods give practically identical results but this is not the same for the thick absorbers. It should be noted that all the spectra were measured at the proton energies significantly above 2 MeV, i.e., in the so-called 'Bethe-Bloch region'. Therefore the observed disagreements in GEANT4 results, simulated with different models, are somewhat unexpected. Further studies are necessary for better understanding and definitive conclusions.

  6. A Geant4 simulation package for the SAGE spectrometer

    International Nuclear Information System (INIS)

    Papadakis, P; Cox, D M; Butler, P A; Herzberg, R-D; Pakarinen, J; Konki, J; Greenlees, P T; Hauschild, K; Rahkila, P; Sandzelius, M; Sorri, J

    2012-01-01

    A comprehensive Geant4 simulation was built for the SAGE spectrometer. The simulation package includes the silicon and germanium detectors, the mechanical structure and the electromagnetic fields present in SAGE. This simulation can be used for making predictions through simulating experiments and for comparing simulated and experimental data to better understand the underlying physics.

  7. A Software Toolkit to Study Systematic Uncertainties of the Physics Models of the Geant4 Simulation Package

    CERN Document Server

    Genser, Krzysztof; Perdue, Gabriel; Wenzel, Hans; Yarba, Julia; Kelsey, Michael; Wright, Dennis H

    2016-01-01

    The Geant4 toolkit is used to model interactions between particles and matter. Geant4 employs a set of validated physics models that span a wide range of interaction energies. These models are tuned to cover a large variety of possible applications. This raises the critical question of what uncertainties are associated with the Geant4 physics model, or group of models, involved in a simulation project. To address the challenge, we have designed and implemented a comprehen- sive, modular, user-friendly software toolkit that allows the variation of one or more parameters of one or more Geant4 physics models involved in simulation studies. It also enables analysis of multiple variants of the resulting physics observables of interest in order to estimate the uncertain- ties associated with the simulation model choices. Key functionalities of the toolkit are presented in this paper and are illustrated with selected results.

  8. Design and performance evaluations of generic programming techniques in a R and D prototype of Geant4 physics

    Energy Technology Data Exchange (ETDEWEB)

    Pia, M G; Saracco, P; Sudhakar, M [INFN Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Zoglauer, A [University of California at Berkeley, Berkeley, CA 94720-7450 (United States); Augelli, M [CNES, 18 Av. Edouard Belin, 31401 Toulouse (France); Gargioni, E [University Medical Center Hamburg-Eppendorf, D-20246 Hamburg (Germany); Kim, C H [Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul, 133-791 (Korea, Republic of); Quintieri, L [INFN Laboratori Nazionali di Frascati, Via Enrico Fermi 40, I-00044 Frascati (Italy); Filho, P P de Queiroz; Santos, D de Souza [IRD, Av. Salvador Allende, s/n. 22780-160, Rio de Janeiro, RJ (Brazil); Weidenspointner, G [MPI fuer extraterrestrische Physik Postfach 1603, D-85740 Garching (Germany); Begalli, M, E-mail: mariagrazia.pia@ge.infn.i [UERJ, R. Sao Francisco Xavier, 524. 20550-013, Rio de Janeiro, RJ (Brazil)

    2010-04-01

    A R and D project has been recently launched to investigate Geant4 architectural design in view of addressing new experimental issues in HEP and other related physics disciplines. In the context of this project the use of generic programming techniques besides the conventional object oriented is investigated. Software design features and preliminary results from a new prototype implementation of Geant4 electromagnetic physics are illustrated. Performance evaluations are presented. Issues related to quality assurance in Geant4 physics modelling are discussed.

  9. Parameterized Shower Simulation in Lelaps: a Comparison with Geant4

    International Nuclear Information System (INIS)

    Langeveld, Willy G.J.

    2003-01-01

    The detector simulation toolkit Lelaps[1] simulates electromagnetic and hadronic showers in calorimetric detector elements of high-energy particle detectors using a parameterization based on the algorithms originally developed by Grindhammer and Peters[2] and Bock et al.[3]. The primary motivations of the present paper are to verify the implementation of the parameterization, to explore regions of energy where the parameterization is valid and to serve as a basis for further improvement of the algorithm. To this end, we compared the Lelaps simulation to a detailed simulation provided by Geant4[4]. A number of different calorimeters, both electromagnetic and hadronic, were implemented in both programs. Longitudinal and radial shower profiles and their fluctuations were obtained from Geant4 over a wide energy range and compared with those obtained from Lelaps. Generally the longitudinal shower profiles are found to be in good agreement in a large part of the energy range, with poorer results at energies below about 300 MeV. Radial profiles agree well in homogeneous detectors, but are somewhat deficient in segmented ones. These deficiencies are discussed

  10. Reanimation of the RICH Test Beam Simulation in GEANT4

    CERN Document Server

    Arzymatov, Kenenbek

    2017-01-01

    This test was originally developed by Sajan Easo (LHCb) ten years ago mostly for the purpose of testing the behavior of photomultipliers, but it wasn’t used in regression testing in Gauss/Geant4 famework. The goal of project is to revive simulation of cherenkov radiaton test by completing.

  11. SU-E-J-72: Geant4 Simulations of Spot-Scanned Proton Beam Treatment Plans

    Energy Technology Data Exchange (ETDEWEB)

    Kanehira, T; Sutherland, K; Matsuura, T; Umegaki, K; Shirato, H [Hokkaido University, Sapporo, Hokkaido (Japan)

    2014-06-01

    Purpose: To evaluate density inhomogeneities which can effect dose distributions for real-time image gated spot-scanning proton therapy (RGPT), a dose calculation system, using treatment planning system VQA (Hitachi Ltd., Tokyo) spot position data, was developed based on Geant4. Methods: A Geant4 application was developed to simulate spot-scanned proton beams at Hokkaido University Hospital. A CT scan (0.98 × 0.98 × 1.25 mm) was performed for prostate cancer treatment with three or four inserted gold markers (diameter 1.5 mm, volume 1.77 mm3) in or near the target tumor. The CT data was read into VQA. A spot scanning plan was generated and exported to text files, specifying the beam energy and position of each spot. The text files were converted and read into our Geant4-based software. The spot position was converted into steering magnet field strength (in Tesla) for our beam nozzle. Individual protons were tracked from the vacuum chamber, through the helium chamber, steering magnets, dose monitors, etc., in a straight, horizontal line. The patient CT data was converted into materials with variable density and placed in a parametrized volume at the isocenter. Gold fiducial markers were represented in the CT data by two adjacent voxels (volume 2.38 mm3). 600,000 proton histories were tracked for each target spot. As one beam contained about 1,000 spots, approximately 600 million histories were recorded for each beam on a blade server. Two plans were considered: two beam horizontal opposed (90 and 270 degree) and three beam (0, 90 and 270 degree). Results: We are able to convert spot scanning plans from VQA and simulate them with our Geant4-based code. Our system can be used to evaluate the effect of dose reduction caused by gold markers used for RGPT. Conclusion: Our Geant4 application is able to calculate dose distributions for spot scanned proton therapy.

  12. Validation of Neutrons in Geant4 Using TARC Data - production, interaction and transportation

    CERN Document Server

    Howard, A

    2007-01-01

    The TARC (Transmutation by Adiabatic Resonance Crossing) experiment has been simulated with the Geant4 toolkit. The experiment measured neutron production from 2.5 GeV/c and 3.5 GeV/c protons incident on high purity lead. The Geant4 simulation utilised either the Bertini or Binary nuclear cascade models together with the low energy neutron HP extension. The neutron time-energy correlation and relative fluence spectrum is compared between data and simulation. A thin target comparison was undertaken for incident protons of energy 800-1600 MeV and for pre-compound evaporation and nuclear de-excitation in the energy range 24-52 MeV.

  13. The local skin dose conversion coefficients of electrons, protons and alpha particles calculated using the Geant4 code.

    Science.gov (United States)

    Zhang, Bintuan; Dang, Bingrong; Wang, Zhuanzi; Wei, Wei; Li, Wenjian

    2013-10-01

    The skin tissue-equivalent slab reported in the International Commission on Radiological Protection (ICRP) Publication 116 to calculate the localised skin dose conversion coefficients (LSDCCs) was adopted into the Monte Carlo transport code Geant4. The Geant4 code was then utilised for computation of LSDCCs due to a circular parallel beam of monoenergetic electrons, protons and alpha particles electrons and alpha particles are found to be in good agreement with the results using the MCNPX code of ICRP 116 data. The present work thus validates the LSDCC values for both electrons and alpha particles using the Geant4 code.

  14. A Software Toolkit to Study Systematic Uncertainties of the Physics Models of the Geant4 Simulation Package

    Science.gov (United States)

    Genser, Krzysztof; Hatcher, Robert; Kelsey, Michael; Perdue, Gabriel; Wenzel, Hans; Wright, Dennis H.; Yarba, Julia

    2017-10-01

    The Geant4 simulation toolkit is used to model interactions between particles and matter. Geant4 employs a set of validated physics models that span a wide range of interaction energies. These models rely on measured cross-sections and phenomenological models with the physically motivated parameters that are tuned to cover many application domains. To study what uncertainties are associated with the Geant4 physics models we have designed and implemented a comprehensive, modular, user-friendly software toolkit that allows the variation of one or more parameters of one or more Geant4 physics models involved in simulation studies. It also enables analysis of multiple variants of the resulting physics observables of interest in order to estimate the uncertainties associated with the simulation model choices. Based on modern event-processing infrastructure software, the toolkit offers a variety of attractive features, e.g. flexible run-time configurable workflow, comprehensive bookkeeping, easy to expand collection of analytical components. Design, implementation technology, and key functionalities of the toolkit are presented in this paper and illustrated with selected results.

  15. Implementation of the n-body Monte-Carlo event generator into the Geant4 toolkit for photonuclear studies

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wen, E-mail: wenluo-ok@163.com [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Lan, Hao-yang [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Xu, Yi; Balabanski, Dimiter L. [Extreme Light Infrastructure-Nuclear Physics, “Horia Hulubei” National Institute for Physics and Nuclear Engineering (IFIN-HH), 30 Reactorului, 077125 Bucharest-Magurele (Romania)

    2017-03-21

    A data-based Monte Carlo simulation algorithm, Geant4-GENBOD, was developed by coupling the n-body Monte-Carlo event generator to the Geant4 toolkit, aiming at accurate simulations of specific photonuclear reactions for diverse photonuclear physics studies. Good comparisons of Geant4-GENBOD calculations with reported measurements of photo-neutron production cross-sections and yields, and with reported energy spectra of the {sup 6}Li(n,α)t reaction were performed. Good agreements between the calculations and experimental data were found and the validation of the developed program was verified consequently. Furthermore, simulations for the {sup 92}Mo(γ,p) reaction of astrophysics relevance and photo-neutron production of {sup 99}Mo/{sup 99m}Tc and {sup 225}Ra/{sup 225}Ac radioisotopes were investigated, which demonstrate the applicability of this program. We conclude that the Geant4-GENBOD is a reliable tool for study of the emerging experiment programs at high-intensity γ-beam laboratories, such as the Extreme Light Infrastructure – Nuclear Physics facility and the High Intensity Gamma-Ray Source at Duke University.

  16. Performance study of a cluster calculation; parallelization and application under geant4

    International Nuclear Information System (INIS)

    Trabelsi, Abir

    2007-01-01

    This work concretizes the final studies project for engineering computer sciences, it is archived within the national center of nuclear sciences and technology. The project consists in studying the performance of a set of machines in order to determine the best architecture to assemble them in a cluster. As well as the parallelism and the parallel implementation of GEANT4, as a tool of simulation. The realisation of this project consists on : 1) programming with C++ and executing the two benchmarks P MV and PMM on each station; 2) Interpreting this result in order to show the best architecture of the cluster; 3) parallelism with TOP-C the two benchmarks; 4) Executing the two Top-C versions on the cluster; 5) Generalizing this results; 6)parallelism et executing the parallel version of GEANT4. (Author). 14 refs

  17. GEANT4 simulations of the n{sub T}OF spallation source and their benchmarking

    Energy Technology Data Exchange (ETDEWEB)

    Lo Meo, S. [Research Centre ' ' Ezio Clementel' ' , ENEA, Bologna (Italy); Section of Bologna, INFN, Bologna (Italy); Cortes-Giraldo, M.A.; Lerendegui-Marco, J.; Guerrero, C.; Quesada, J.M. [Universidad de Sevilla, Facultad de Fisica, Sevilla (Spain); Massimi, C.; Vannini, G. [Section of Bologna, INFN, Bologna (Italy); University of Bologna, Physics and Astronomy Dept. ' ' Alma Mater Studiorum' ' , Bologna (Italy); Barbagallo, M.; Colonna, N. [INFN, Section of Bari, Bari (Italy); Mancusi, D. [CEA-Saclay, DEN, DM2S, SERMA, LTSD, Gif-sur-Yvette CEDEX (France); Mingrone, F. [Section of Bologna, INFN, Bologna (Italy); Sabate-Gilarte, M. [Universidad de Sevilla, Facultad de Fisica, Sevilla (Spain); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Vlachoudis, V. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Collaboration: The n_TOF Collaboration

    2015-12-15

    Neutron production and transport in the spallation target of the n{sub T}OF facility at CERN has been simulated with GEANT4. The results obtained with different models of high-energy nucleon-nucleus interaction have been compared with the measured characteristics of the neutron beam, in particular the flux and its dependence on neutron energy, measured in the first experimental area. The best agreement at present, within 20% for the absolute value of the flux, and within few percent for the energy dependence in the whole energy range from thermal to 1 GeV, is obtained with the INCL++ model coupled with the GEANT4 native de-excitation model. All other available models overestimate by a larger factor, of up to 70%, the n{sub T}OF neutron flux. The simulations are also able to accurately reproduce the neutron beam energy resolution function, which is essentially determined by the moderation time inside the target/moderator assembly. The results here reported provide confidence on the use of GEANT4 for simulations of spallation neutron sources. (orig.)

  18. Modeling a gamma spectroscopy system and predicting spectra with Geant-4

    International Nuclear Information System (INIS)

    Sahin, D.; Uenlue, K.

    2009-01-01

    An activity predictor software was previously developed to foresee activities, exposure rates and gamma spectra of activated samples for Radiation Science and Engineering Center (RSEC), Penn State Breazeale Reactor (PSBR), Neutron Activation Analysis (NAA) measurements. With Activity Predictor it has been demonstrated that the predicted spectra were less than satisfactory. In order to obtain better predicted spectra, a new detailed model for the RSEC NAA spectroscopy system with High Purity Germanium (HPGe) detector is developed using Geant-4. The model was validated with a National Bureau of Standards certified 60 Co source and tree activated high purity samples at PSBR. The predicted spectra agreed well with measured spectra. Error in net photo peak area values were 8.6-33.6%. Along with the previously developed activity predictor software, this new model in Geant-4 provided realistic spectra prediction for NAA experiments at RSEC PSBR. (author)

  19. Calibration of the radiation monitor onboard Akebono using Geant4

    Science.gov (United States)

    Asai, Keiko; Takashima, Takeshi; Koi, Tatsumi; Nagai, Tsugunobu

    Natural high-energy electrons and protons (keV-MeV) in the space contaminate the data re-ciprocally. In order to calibrate the energy ranges and to remove data contamination on the radiation monitor (RDM) onboard the Japanese satellite, Akebono (EXOS-D), the detector is investigated using the Geant4 simulation toolkit of computational particle tracing. The semi-polar orbiting Akebono, launched in February 1989, is active now. This satellite has been observed the space environment at altitudes of several thousands km. The RDM instrument onboard Akebono monitors energetic particles in the Earth's radiation belt and gives important data accumulated for about two solar cycles. The data from RDM are for electrons in three energy channels of 0.3 MeV, protons in three energy channels of ¿ 30 MeV, and alpha particles in one energy channels of 15-45 MeV. The energy ranges are however based on information of about 20 years ago so that the data seem to include some errors actuary. In addition, these data include contamination of electrons and protons reciprocally. Actuary it is noticed that the electron data are contaminated by the solar protons but unknown quantitative amount of the contamination. Therefore we need data calibration in order to correct the energy ranges and to remove data contamination. The Geant4 simulation gives information of trajectories of incident and secondary particles whose are interacted with materials. We examine the RDM monitor using the Geant4 simulation. We find from the results that relativistic electrons of MeV behave quite complicatedly because of particle-material interaction in the instrument. The results indicate that efficiencies of detection and contamination are dependent on energy. This study compares the electron data from Akebono RDM with the simultaneous observation of CRRES and tries to lead the values of correction for each of the energy channels.

  20. Visualization drivers for Geant4

    International Nuclear Information System (INIS)

    Beretvas, Andy

    2005-01-01

    This document is on Geant 4 visualization tools (drivers), evaluating pros and cons of each option, including recommendations on which tools to support at Fermilab for different applications. Four visualization drivers are evaluated. They re OpenGL, HepRep, DAWN and VRML. They all have good features, OpenGL provides graphic output with out an intermediate file. HepRep provides menus to assist the user. DAWN provides high quality plots and even for large files produces output quickly. VRML uses the smallest disk space for intermediate files. Large experiments at Fermilab will want to write their own display. They should proceed to make this display graphics independent. Medium experiment will probably want to use HepRep because of it's menu support. Smaller scale experiments will want to use OpenGL in the spirit of having immediate response, good quality output and keeping things simple

  1. Assessment of Geant4 Prompt-Gamma Emission Yields in the Context of Proton Therapy Monitoring

    Science.gov (United States)

    Pinto, Marco; Dauvergne, Denis; Freud, Nicolas; Krimmer, Jochen; Létang, Jean M.; Testa, Etienne

    2016-01-01

    Monte Carlo tools have been long used to assist the research and development of solutions for proton therapy monitoring. The present work focuses on the prompt-gamma emission yields by comparing experimental data with the outcomes of the current version of Geant4 using all applicable proton inelastic models. For the case in study and using the binary cascade model, it was found that Geant4 overestimates the prompt-gamma emission yields by 40.2 ± 0.3%, even though it predicts the prompt-gamma profile length of the experimental profile accurately. In addition, the default implementations of all proton inelastic models show an overestimation in the number of prompt gammas emitted. Finally, a set of built-in options and physically sound Geant4 source code changes have been tested in order to try to improve the discrepancy observed. A satisfactory agreement was found when using the QMD model with a wave packet width equal to 1.3 fm2. PMID:26858937

  2. A Toolkit to Study Sensitivity of the Geant4 Predictions to the Variations of the Physics Model Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Laura [Fermilab; Genser, Krzysztof [Fermilab; Hatcher, Robert [Fermilab; Kelsey, Michael [SLAC; Perdue, Gabriel [Fermilab; Wenzel, Hans [Fermilab; Wright, Dennis H. [SLAC; Yarba, Julia [Fermilab

    2017-08-21

    Geant4 is the leading detector simulation toolkit used in high energy physics to design detectors and to optimize calibration and reconstruction software. It employs a set of carefully validated physics models to simulate interactions of particles with matter across a wide range of interaction energies. These models, especially the hadronic ones, rely largely on directly measured cross-sections and phenomenological predictions with physically motivated parameters estimated by theoretical calculation or measurement. Because these models are tuned to cover a very wide range of possible simulation tasks, they may not always be optimized for a given process or a given material. This raises several critical questions, e.g. how sensitive Geant4 predictions are to the variations of the model parameters, or what uncertainties are associated with a particular tune of a Geant4 physics model, or a group of models, or how to consistently derive guidance for Geant4 model development and improvement from a wide range of available experimental data. We have designed and implemented a comprehensive, modular, user-friendly software toolkit to study and address such questions. It allows one to easily modify parameters of one or several Geant4 physics models involved in the simulation, and to perform collective analysis of multiple variants of the resulting physics observables of interest and comparison against a variety of corresponding experimental data. Based on modern event-processing infrastructure software, the toolkit offers a variety of attractive features, e.g. flexible run-time configurable workflow, comprehensive bookkeeping, easy to expand collection of analytical components. Design, implementation technology, and key functionalities of the toolkit are presented and illustrated with results obtained with Geant4 key hadronic models.

  3. Calculation of neutron fluence to dose equivalent conversion coefficients using GEANT4; Calculo de coeficientes de fluencia de neutrons para equivalente de dose individual utilizando o GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Rosane M.; Santos, Denison de S.; Queiroz Filho, Pedro P. de; Mauricio, CLaudia L.P.; Silva, Livia K. da; Pessanha, Paula R., E-mail: rosanemribeiro@oi.com.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Fluence to dose equivalent conversion coefficients provide the basis for the calculation of area and personal monitors. Recently, the ICRP has started a revision of these coefficients, including new Monte Carlo codes for benchmarking. So far, little information is available about neutron transport below 10 MeV in tissue-equivalent (TE) material performed with Monte Carlo GEANT4 code. The objective of this work is to calculate neutron fluence to personal dose equivalent conversion coefficients, H{sub p} (10)/Φ, with GEANT4 code. The incidence of monoenergetic neutrons was simulated as an expanded and aligned field, with energies ranging between thermal neutrons to 10 MeV on the ICRU slab of dimension 30 x 30 x 15 cm{sup 3}, composed of 76.2% of oxygen, 10.1% of hydrogen, 11.1% of carbon and 2.6% of nitrogen. For all incident energy, a cylindrical sensitive volume is placed at a depth of 10 mm, in the largest surface of the slab (30 x 30 cm{sup 2}). Physic process are included for neutrons, photons and charged particles, and calculations are made for neutrons and secondary particles which reach the sensitive volume. Results obtained are thus compared with values published in ICRP 74. Neutron fluence in the sensitive volume was calculated for benchmarking. The Monte Carlo GEANT4 code was found to be appropriate to calculate neutron doses at energies below 10 MeV correctly. (author)

  4. Extension of PENELOPE to protons: Simulation of nuclear reactions and benchmark with Geant4

    International Nuclear Information System (INIS)

    Sterpin, E.; Sorriaux, J.; Vynckier, S.

    2013-01-01

    Purpose: Describing the implementation of nuclear reactions in the extension of the Monte Carlo code (MC) PENELOPE to protons (PENH) and benchmarking with Geant4.Methods: PENH is based on mixed-simulation mechanics for both elastic and inelastic electromagnetic collisions (EM). The adopted differential cross sections for EM elastic collisions are calculated using the eikonal approximation with the Dirac–Hartree–Fock–Slater atomic potential. Cross sections for EM inelastic collisions are computed within the relativistic Born approximation, using the Sternheimer–Liljequist model of the generalized oscillator strength. Nuclear elastic and inelastic collisions were simulated using explicitly the scattering analysis interactive dialin database for 1 H and ICRU 63 data for 12 C, 14 N, 16 O, 31 P, and 40 Ca. Secondary protons, alphas, and deuterons were all simulated as protons, with the energy adapted to ensure consistent range. Prompt gamma emission can also be simulated upon user request. Simulations were performed in a water phantom with nuclear interactions switched off or on and integral depth–dose distributions were compared. Binary-cascade and precompound models were used for Geant4. Initial energies of 100 and 250 MeV were considered. For cases with no nuclear interactions simulated, additional simulations in a water phantom with tight resolution (1 mm in all directions) were performed with FLUKA. Finally, integral depth–dose distributions for a 250 MeV energy were computed with Geant4 and PENH in a homogeneous phantom with, first, ICRU striated muscle and, second, ICRU compact bone.Results: For simulations with EM collisions only, integral depth–dose distributions were within 1%/1 mm for doses higher than 10% of the Bragg-peak dose. For central-axis depth–dose and lateral profiles in a phantom with tight resolution, there are significant deviations between Geant4 and PENH (up to 60%/1 cm for depth–dose distributions). The agreement is much

  5. Extension of PENELOPE to protons: simulation of nuclear reactions and benchmark with Geant4.

    Science.gov (United States)

    Sterpin, E; Sorriaux, J; Vynckier, S

    2013-11-01

    Describing the implementation of nuclear reactions in the extension of the Monte Carlo code (MC) PENELOPE to protons (PENH) and benchmarking with Geant4. PENH is based on mixed-simulation mechanics for both elastic and inelastic electromagnetic collisions (EM). The adopted differential cross sections for EM elastic collisions are calculated using the eikonal approximation with the Dirac-Hartree-Fock-Slater atomic potential. Cross sections for EM inelastic collisions are computed within the relativistic Born approximation, using the Sternheimer-Liljequist model of the generalized oscillator strength. Nuclear elastic and inelastic collisions were simulated using explicitly the scattering analysis interactive dialin database for (1)H and ICRU 63 data for (12)C, (14)N, (16)O, (31)P, and (40)Ca. Secondary protons, alphas, and deuterons were all simulated as protons, with the energy adapted to ensure consistent range. Prompt gamma emission can also be simulated upon user request. Simulations were performed in a water phantom with nuclear interactions switched off or on and integral depth-dose distributions were compared. Binary-cascade and precompound models were used for Geant4. Initial energies of 100 and 250 MeV were considered. For cases with no nuclear interactions simulated, additional simulations in a water phantom with tight resolution (1 mm in all directions) were performed with FLUKA. Finally, integral depth-dose distributions for a 250 MeV energy were computed with Geant4 and PENH in a homogeneous phantom with, first, ICRU striated muscle and, second, ICRU compact bone. For simulations with EM collisions only, integral depth-dose distributions were within 1%/1 mm for doses higher than 10% of the Bragg-peak dose. For central-axis depth-dose and lateral profiles in a phantom with tight resolution, there are significant deviations between Geant4 and PENH (up to 60%/1 cm for depth-dose distributions). The agreement is much better with FLUKA, with deviations within

  6. Optimisation of a dual head semiconductor Compton camera using Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Harkness, L.J. [Department of Physics, University of Liverpool, Oliver Lodge Laboratory, Liverpool L697ZE (United Kingdom)], E-mail: ljh@ns.ph.liv.ac.uk; Boston, A.J.; Boston, H.C.; Cooper, R.J.; Cresswell, J.R.; Grint, A.N.; Nolan, P.J.; Oxley, D.C.; Scraggs, D.P. [Department of Physics, University of Liverpool, Oliver Lodge Laboratory, Liverpool L697ZE (United Kingdom); Beveridge, T.; Gillam, J. [School of Physics and Materials Engineering, Monash University, Melbourne (Australia); Lazarus, I. [STFC Daresbury Laboratory, Warrington, Cheshire (United Kingdom)

    2009-06-01

    Conventional medical gamma-ray camera systems utilise mechanical collimation to provide information on the position of an incident gamma-ray photon. Systems that use electronic collimation utilising Compton image reconstruction techniques have the potential to offer huge improvements in sensitivity. Position sensitive high purity germanium (HPGe) detector systems are being evaluated as part of a single photon emission computed tomography (SPECT) Compton camera system. Data have been acquired from the orthogonally segmented planar SmartPET detectors, operated in Compton camera mode. The minimum gamma-ray energy which can be imaged by the current system in Compton camera configuration is 244 keV due to the 20 mm thickness of the first scatter detector which causes large gamma-ray absorption. A simulation package for the optimisation of a new semiconductor Compton camera has been developed using the Geant4 toolkit. This paper will show results of preliminary analysis of the validated Geant4 simulation for gamma-ray energies of SPECT, 141 keV.

  7. GePEToS: A Geant4 Monte Carlo simulation package for positron emission tomography

    International Nuclear Information System (INIS)

    Jan, Sebastien; Collot, Johann; Gallin-Martel, Marie-Laure; Martin, Philippe; Mayet, Frederic; Tournefier, Edwige

    2003-01-01

    GePEToS is a simulation framework developed over the last few years for assessing the instrumental performance of future PET scanners. It is based on Geant4, written in Object- Oriented C++ and runs on Linux platforms. The validity of GePEToS has been tested on the well-known Siemens ECAT EXACT HR+ camera. The results of two application examples are presented: the design optimization of a liquid Xe μPET camera dedicated to small animal imaging as well as the evaluation of the effect of a strong axial magnetic field on the image resolution of a Concorde P4 μPET camera. Index Terms-Positron Emission Tomography, Monte Carlo Simulation, Geant 4. (authors)

  8. Calculation of neutron fluence to dose equivalent conversion coefficients using GEANT4

    International Nuclear Information System (INIS)

    Ribeiro, Rosane M.; Santos, Denison de S.; Queiroz Filho, Pedro P. de; Mauricio, CLaudia L.P.; Silva, Livia K. da; Pessanha, Paula R.

    2014-01-01

    Fluence to dose equivalent conversion coefficients provide the basis for the calculation of area and personal monitors. Recently, the ICRP has started a revision of these coefficients, including new Monte Carlo codes for benchmarking. So far, little information is available about neutron transport below 10 MeV in tissue-equivalent (TE) material performed with Monte Carlo GEANT4 code. The objective of this work is to calculate neutron fluence to personal dose equivalent conversion coefficients, H p (10)/Φ, with GEANT4 code. The incidence of monoenergetic neutrons was simulated as an expanded and aligned field, with energies ranging between thermal neutrons to 10 MeV on the ICRU slab of dimension 30 x 30 x 15 cm 3 , composed of 76.2% of oxygen, 10.1% of hydrogen, 11.1% of carbon and 2.6% of nitrogen. For all incident energy, a cylindrical sensitive volume is placed at a depth of 10 mm, in the largest surface of the slab (30 x 30 cm 2 ). Physic process are included for neutrons, photons and charged particles, and calculations are made for neutrons and secondary particles which reach the sensitive volume. Results obtained are thus compared with values published in ICRP 74. Neutron fluence in the sensitive volume was calculated for benchmarking. The Monte Carlo GEANT4 code was found to be appropriate to calculate neutron doses at energies below 10 MeV correctly. (author)

  9. Geant4 - A Simulation Toolkit

    International Nuclear Information System (INIS)

    2002-01-01

    Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. it has been designed and constructed to expose the physics models utilized, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics

  10. GEANT4 A Simulation toolkit

    CERN Document Server

    Agostinelli, S; Amako, K; Apostolakis, John; Araújo, H M; Arce, P; Asai, M; Axen, D A; Banerjee, S; Barrand, G; Behner, F; Bellagamba, L; Boudreau, J; Broglia, L; Brunengo, A; Chauvie, S; Chuma, J; Chytracek, R; Cooperman, G; Cosmo, G; Degtyarenko, P V; Dell'Acqua, A; De Paola, G O; Dietrich, D D; Enami, R; Feliciello, A; Ferguson, C; Fesefeldt, H S; Folger, G; Foppiano, F; Forti, A C; Garelli, S; Giani, S; Giannitrapani, R; Gibin, D; Gómez-Cadenas, J J; González, I; Gracía-Abríl, G; Greeniaus, L G; Greiner, W; Grichine, V M; Grossheim, A; Gumplinger, P; Hamatsu, R; Hashimoto, K; Hasui, H; Heikkinen, A M; Howard, A; Hutton, A M; Ivanchenko, V N; Johnson, A; Jones, F W; Kallenbach, Jeff; Kanaya, N; Kawabata, M; Kawabata, Y; Kawaguti, M; Kelner, S; Kent, P; Kodama, T; Kokoulin, R P; Kossov, M; Kurashige, H; Lamanna, E; Lampen, T; Lara, V; Lefébure, V; Lei, F; Liendl, M; Lockman, W; Longo, F; Magni, S; Maire, M; Mecking, B A; Medernach, E; Minamimoto, K; Mora de Freitas, P; Morita, Y; Murakami, K; Nagamatu, M; Nartallo, R; Nieminen, P; Nishimura, T; Ohtsubo, K; Okamura, M; O'Neale, S W; O'Ohata, Y; Perl, J; Pfeiffer, A; Pia, M G; Ranjard, F; Rybin, A; Sadilov, S; Di Salvo, E; Santin, G; Sasaki, T; Savvas, N; Sawada, Y; Scherer, S; Sei, S; Sirotenko, V I; Smith, D; Starkov, N; Stöcker, H; Sulkimo, J; Takahata, M; Tanaka, S; Chernyaev, E; Safai-Tehrani, F; Tropeano, M; Truscott, P R; Uno, H; Urbàn, L; Urban, P; Verderi, M; Walkden, A; Wander, W; Weber, H; Wellisch, J P; Wenaus, T; Williams, D C; Wright, D; Yamada, T; Yoshida, H; Zschiesche, D

    2003-01-01

    Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics.

  11. Geant4 - A Simulation Toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Dennis H

    2002-08-09

    GEANT4 is a toolkit for simulating the passage of particles through matter. it includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. it has been designed and constructed to expose the physics models utilized, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics.

  12. Benchmarking nuclear models of FLUKA and GEANT4 for carbon ion therapy

    CERN Document Server

    Bohlen, TT; Quesada, J M; Bohlen, T T; Cerutti, F; Gudowska, I; Ferrari, A; Mairani, A

    2010-01-01

    As carbon ions, at therapeutic energies, penetrate tissue, they undergo inelastic nuclear reactions and give rise to significant yields of secondary fragment fluences. Therefore, an accurate prediction of these fluences resulting from the primary carbon interactions is necessary in the patient's body in order to precisely simulate the spatial dose distribution and the resulting biological effect. In this paper, the performance of nuclear fragmentation models of the Monte Carlo transport codes, FLUKA and GEANT4, in tissue-like media and for an energy regime relevant for therapeutic carbon ions is investigated. The ability of these Monte Carlo codes to reproduce experimental data of charge-changing cross sections and integral and differential yields of secondary charged fragments is evaluated. For the fragment yields, the main focus is on the consideration of experimental approximations and uncertainties such as the energy measurement by time-of-flight. For GEANT4, the hadronic models G4BinaryLightIonReaction a...

  13. Geant4-DNA track-structure simulations for gold nanoparticles: The importance of electron discrete models in nanometer volumes.

    Science.gov (United States)

    Sakata, Dousatsu; Kyriakou, Ioanna; Okada, Shogo; Tran, Hoang N; Lampe, Nathanael; Guatelli, Susanna; Bordage, Marie-Claude; Ivanchenko, Vladimir; Murakami, Koichi; Sasaki, Takashi; Emfietzoglou, Dimitris; Incerti, Sebastien

    2018-05-01

    Gold nanoparticles (GNPs) are known to enhance the absorbed dose in their vicinity following photon-based irradiation. To investigate the therapeutic effectiveness of GNPs, previous Monte Carlo simulation studies have explored GNP dose enhancement using mostly condensed-history models. However, in general, such models are suitable for macroscopic volumes and for electron energies above a few hundred electron volts. We have recently developed, for the Geant4-DNA extension of the Geant4 Monte Carlo simulation toolkit, discrete physics models for electron transport in gold which include the description of the full atomic de-excitation cascade. These models allow event-by-event simulation of electron tracks in gold down to 10 eV. The present work describes how such specialized physics models impact simulation-based studies on GNP-radioenhancement in a context of x-ray radiotherapy. The new discrete physics models are compared to the Geant4 Penelope and Livermore condensed-history models, which are being widely used for simulation-based NP radioenhancement studies. An ad hoc Geant4 simulation application has been developed to calculate the absorbed dose in liquid water around a GNP and its radioenhancement, caused by secondary particles emitted from the GNP itself, when irradiated with a monoenergetic electron beam. The effect of the new physics models is also quantified in the calculation of secondary particle spectra, when originating in the GNP and when exiting from it. The new physics models show similar backscattering coefficients with the existing Geant4 Livermore and Penelope models in large volumes for 100 keV incident electrons. However, in submicron sized volumes, only the discrete models describe the high backscattering that should still be present around GNPs at these length scales. Sizeable differences (mostly above a factor of 2) are also found in the radial distribution of absorbed dose and secondary particles between the new and the existing Geant4

  14. Simulation of AntiMatter–Matter Interactions in Geant4

    Directory of Open Access Journals (Sweden)

    Galoyan Aida

    2018-01-01

    Full Text Available Cross sections of antiproton and antinucleus interactions with nuclei are calculated using stochastic averaging method. A new implementation of the Quark-Gluon-String Model (QGSM is proposed for simulation of multi-particle production in antinucleus-nucleus collisions. A combination of the cross sections and the new implementation of QGSM allows experimental data on antiproton and antinucleus interactions with nuclei to be described. The combination is included in the well-known Geant4 simulation toolkit.

  15. Design and construction of a graphical interface for automatic generation of simulation code GEANT4

    International Nuclear Information System (INIS)

    Driss, Mozher; Bouzaine Ismail

    2007-01-01

    This work is set in the context of the engineering studies final project; it is accomplished in the center of nuclear sciences and technologies in Sidi Thabet. This project is about conceiving and developing a system based on graphical user interface which allows an automatic codes generation for simulation under the GEANT4 engine. This system aims to facilitate the use of GEANT4 by scientific not necessary expert in this engine and to be used in different areas: research, industry and education. The implementation of this project uses Root library and several programming languages such as XML and XSL. (Author). 5 refs

  16. CHIPS_TPT models for exclusive Geant4 simulation of neutron-nuclear reactions at low energies

    Directory of Open Access Journals (Sweden)

    Kosov Mikhail V.

    2014-03-01

    Full Text Available A novel TPT code (Toolkit for Particle Transport, which is included in CHIPS_TPT physics list for Geant4 simulations, is briefly overviewed. Underlying concept of exclusive modelling is introduced and its beneficial features are illustrated with several examples. Widely used neutron Monte Carlo codes, MCNP and Geant4/HP, are based on inclusive algorithms that independently model neutron state change and secondary particles production while tracking. The exclusive approach implemented in TPT overcomes this unphysical separation and makes it possible to allow for kinematic restrictions as well as correlated emission of gamma-rays and secondaries.

  17. NaI(Tl) detectors modeling in MCNP-X and Gate/Geant4 codes

    Energy Technology Data Exchange (ETDEWEB)

    Affonso, Renato Raoni Werneck; Silva, Ademir Xavier da, E-mail: raoniwa@yahoo.com.br, E-mail: ademir@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Salgado, Cesar Marques, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    NaI (Tl) detectors are widely used in gamma-ray densitometry, but their modeling in Monte Carlo codes, such as MCNP-X and Gate/Geant4, needs a lot of work and does not yield comparable results with experimental arrangements, possibly due to non-simulated physical phenomena, such as light transport within the scintillator. Therefore, it is necessary a methodology that positively impacts the results of the simulations while maintaining the real dimensions of the detectors and other objects to allow validating a modeling that matches up with the experimental arrangement. Thus, the objective of this paper is to present the studies conducted with the MCNPX and Gate/Geant4 codes, in which the comparisons of their results were satisfactory, showing that both can be used for the same purposes. (author)

  18. Monte Carlo application based on GEANT4 toolkit to simulate a laser–plasma electron beam line for radiobiological studies

    Energy Technology Data Exchange (ETDEWEB)

    Lamia, D., E-mail: debora.lamia@ibfm.cnr.it [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Russo, G., E-mail: giorgio.russo@ibfm.cnr.it [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Casarino, C.; Gagliano, L.; Candiano, G.C. [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Labate, L. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); National Institute for Nuclear Physics INFN, Pisa Section and Frascati National Laboratories LNF (Italy); Baffigi, F.; Fulgentini, L.; Giulietti, A.; Koester, P.; Palla, D. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); Gizzi, L.A. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); National Institute for Nuclear Physics INFN, Pisa Section and Frascati National Laboratories LNF (Italy); Gilardi, M.C. [Institute of Molecular Bioimaging and Physiology IBFM CNR, Segrate (Italy); University of Milano-Bicocca, Milano (Italy)

    2015-06-21

    We report on the development of a Monte Carlo application, based on the GEANT4 toolkit, for the characterization and optimization of electron beams for clinical applications produced by a laser-driven plasma source. The GEANT4 application is conceived so as to represent in the most general way the physical and geometrical features of a typical laser-driven accelerator. It is designed to provide standard dosimetric figures such as percentage dose depth curves, two-dimensional dose distributions and 3D dose profiles at different positions both inside and outside the interaction chamber. The application was validated by comparing its predictions to experimental measurements carried out on a real laser-driven accelerator. The work is aimed at optimizing the source, by using this novel application, for radiobiological studies and, in perspective, for medical applications. - Highlights: • Development of a Monte Carlo application based on GEANT4 toolkit. • Experimental measurements carried out with a laser-driven acceleration system. • Validation of Geant4 application comparing experimental data with the simulated ones. • Dosimetric characterization of the acceleration system.

  19. Recent progress of GEANT4 electromagnetic physics for LHC and other applications

    NARCIS (Netherlands)

    Bagulya, A.; Brown, J.M.C.; Burkhardt, H.; Grichine, V.; Guatelli, S.; Incerti, S.; Ivanchenko, V. N.; Kadri, O.; Karamitros, M.; Maire, M.; Mashtakov, K.; Novak, M; Pandola, L.; Rancoita, P. G.; Sawkey, D.; Tacconi, M.; Urban, L.

    2017-01-01

    We report on the recent progress within the Geant4 electromagnetic physics subpackages. Several new interfaces and models recently introduced are already used in LHC applications and may be useful for any type of simulation. Significant developments were carried out to improve the user interface,

  20. Comparison of Geant4-DNA simulation of S-values with other Monte Carlo codes

    International Nuclear Information System (INIS)

    André, T.; Morini, F.; Karamitros, M.; Delorme, R.; Le Loirec, C.; Campos, L.; Champion, C.; Groetz, J.-E.; Fromm, M.; Bordage, M.-C.; Perrot, Y.; Barberet, Ph.

    2014-01-01

    Monte Carlo simulations of S-values have been carried out with the Geant4-DNA extension of the Geant4 toolkit. The S-values have been simulated for monoenergetic electrons with energies ranging from 0.1 keV up to 20 keV, in liquid water spheres (for four radii, chosen between 10 nm and 1 μm), and for electrons emitted by five isotopes of iodine (131, 132, 133, 134 and 135), in liquid water spheres of varying radius (from 15 μm up to 250 μm). The results have been compared to those obtained from other Monte Carlo codes and from other published data. The use of the Kolmogorov–Smirnov test has allowed confirming the statistical compatibility of all simulation results

  1. An Algorithm for Computing Screened Coulomb Scattering in Geant4

    OpenAIRE

    Mendenhall, Marcus H.; Weller, Robert A.

    2004-01-01

    An algorithm has been developed for the Geant4 Monte-Carlo package for the efficient computation of screened Coulomb interatomic scattering. It explicitly integrates the classical equations of motion for scattering events, resulting in precise tracking of both the projectile and the recoil target nucleus. The algorithm permits the user to plug in an arbitrary screening function, such as Lens-Jensen screening, which is good for backscattering calculations, or Ziegler-Biersack-Littmark screenin...

  2. Simulation of ALTEA calibration data with PHITS, FLUKA and GEANT4

    International Nuclear Information System (INIS)

    La Tessa, C.; Di Fino, L.; Larosa, M.; Lee, K.; Mancusi, D.; Matthiae, D.; Narici, L.; Zaconte, V.

    2009-01-01

    The ALTEA-Space detector has been calibrated by testing its response to several monochromatic beams. These measurements provided energy-deposition spectra in silicon of 100, 600 and 1000 MeV/nucleon 12 C and 200 and 600 MeV/nucleon 48 Ti. The results have been compared to three Monte Carlo transport codes, namely PHITS, GEANT4 and FLUKA. Median, full width at half maximum (FWHM) and interquartile range (IQR) have been calculated for all datasets to characterize location, width and asymmetry of the energy-deposition spectra. Particular attention has been devoted to the influence of δ rays on the shape of the energy-deposition spectrum, both with the help of analytical calculations and Monte Carlo simulations. The two approaches proved that, in this range of projectile charge, projectile energy and detector size, the leakage of secondary electrons might introduce a difference between the energy-loss and energy-deposition spectrum, in particular by changing the location, width and symmetry of the distribution. The overall agreement between the Monte Carlo predictions and the measurements is fair and makes PHITS, FLUKA and GEANT4 all possible candidates for simulating ALTEA-Space experiment.

  3. Monte Carlo simulation of a photodisintegration of 3 H experiment in Geant4

    Science.gov (United States)

    Gray, Isaiah

    2013-10-01

    An upcoming experiment involving photodisintegration of 3 H at the High Intensity Gamma-Ray Source facility at Duke University has been simulated in the software package Geant4. CAD models of silicon detectors and wire chambers were imported from Autodesk Inventor using the program FastRad and the Geant4 GDML importer. Sensitive detectors were associated with the appropriate logical volumes in the exported GDML file so that changes in detector geometry will be easily manifested in the simulation. Probability distribution functions for the energy and direction of outgoing protons were generated using numerical tables from previous theory, and energies and directions were sampled from these distributions using a rejection sampling algorithm. The simulation will be a useful tool to optimize detector geometry, estimate background rates, and test data analysis algorithms. This work was supported by the Triangle Universities Nuclear Laboratory REU program at Duke University.

  4. Automatic modeling for the Monte Carlo transport code Geant4

    International Nuclear Information System (INIS)

    Nie Fanzhi; Hu Liqin; Wang Guozhong; Wang Dianxi; Wu Yican; Wang Dong; Long Pengcheng; FDS Team

    2015-01-01

    Geant4 is a widely used Monte Carlo transport simulation package. Its geometry models could be described in Geometry Description Markup Language (GDML), but it is time-consuming and error-prone to describe the geometry models manually. This study implemented the conversion between computer-aided design (CAD) geometry models and GDML models. This method has been Studied based on Multi-Physics Coupling Analysis Modeling Program (MCAM). The tests, including FDS-Ⅱ model, demonstrated its accuracy and feasibility. (authors)

  5. Refactoring, reengineering and evolution: paths to Geant4 uncertainty quantification and performance improvement

    International Nuclear Information System (INIS)

    Batič, M; Hoff, G; Pia, M G; Saracco, P; Begalli, M; Han, M; Kim, C H; Seo, H; Hauf, S; Kuster, M; Weidenspointner, G; Zoglauer, A

    2012-01-01

    Ongoing investigations for the improvement of Geant4 accuracy and computational performance resulting by refactoring and reengineering parts of the code are discussed. Issues in refactoring that are specific to the domain of physics simulation are identified and their impact is elucidated. Preliminary quantitative results are reported.

  6. Geant4 and Fano cavity test: where are we?

    CERN Document Server

    Elles, S; Maire, M; Urbàn, L

    2008-01-01

    The electron transport algorithm implemented in Geant4 has been recently revised. The modifications concern several physics aspects of the simulation model: the step limitation, the energy loss along a step and the multiple scattering. The Fano cavity setup was used to test these developments. The upgrades increase significantly the accuracy of the electron transport simulation. The ratio of simulated to theoretical dose deposition in the cavity is stable to ~1% while varying several parameters and within ~1.5% of the expected value for water and graphite. Work is underway to identify and resolve the remaining shift.

  7. Geant4-DNA coupling and validation in the GATE Monte Carlo platform for DNA molecules irradiation in a calculation grid environment

    International Nuclear Information System (INIS)

    Pham, Quang Trung

    2014-01-01

    The Monte Carlo simulation methods are successfully being used in various areas of medical physics but also at different scales, for example, from the radiation therapy treatment planning systems to the prediction of the effects of radiation in cancer cells. The Monte Carlo simulation platform GATE based on the Geant4 tool-kit offers features dedicated to simulations in medical physics (nuclear medicine and radiotherapy). For radiobiology applications, the Geant4-DNA physical models are implemented to track particles till very low energy (eV) and are adapted for estimation of micro-dosimetric quantities. In order to implement a multi-scale Monte Carlo platform, we first validated the physical models of Geant4-DNA, and integrated them into GATE. Finally, we validated this implementation in the context of radiation therapy and proton therapy. In order to validate the Geant4-DNA physical models, dose point kernels for monoenergetic electrons (10 keV to 100 keV) were simulated using the physical models of Geant4-DNA and were compared to those simulated with Geant4 Standard physical models and another Monte Carlo code EGSnrc. The range and the stopping powers of electrons (7.4 eV to 1 MeV) and protons (1 keV to 100 MeV) calculated with GATE/Geant4-DNA were then compared with literature. We proposed to simulate with the GATE platform the impact of clinical and preclinical beams on cellular DNA. We modeled a clinical proton beam of 193.1 MeV, 6 MeV clinical electron beam and a X-ray irradiator beam. The beams models were validated by comparing absorbed dose computed and measured in liquid water. Then, the beams were used to calculate the frequency of energy deposits in DNA represented by different geometries. First, the DNA molecule was represented by small cylinders: 2 nm x 2 nm (∼10 bp), 5 nm x 10 nm (nucleosome) and 25 nm x 25 nm (chromatin fiber). All these cylinders were placed randomly in a sphere of liquid water (500 nm radius). Then we reconstructed the DNA

  8. Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry

    International Nuclear Information System (INIS)

    Chagren, S.; Tekaya, M.Ben; Reguigui, N.; Gharbi, F.

    2016-01-01

    In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a “virtual” reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60–2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed. - Highlights: • The GEANT4 code of CERN has been used to transfer the peak efficiency from point to points and voluminous detection configurations in HPGe gamma

  9. Geant4-based simulations of charge collection in CMOS Active Pixel Sensors

    International Nuclear Information System (INIS)

    Esposito, M.; Allinson, N.M.; Price, T.; Anaxagoras, T.

    2017-01-01

    Geant4 is an object-oriented toolkit for the simulation of the interaction of particles and radiation with matter. It provides a snapshot of the state of a simulated particle in time, as it travels through a specified geometry. One important area of application is the modelling of radiation detector systems. Here, we extend the abilities of such modelling to include charge transport and sharing in pixelated CMOS Active Pixel Sensors (APSs); though similar effects occur in other pixel detectors. The CMOS APSs discussed were developed in the framework of the PRaVDA consortium to assist the design of custom sensors to be used in an energy-range detector for proton Computed Tomography (pCT). The development of ad-hoc classes, providing a charge transport model for a CMOS APS and its integration into the standard Geant4 toolkit, is described. The proposed charge transport model includes, charge generation, diffusion, collection, and sharing across adjacent pixels, as well as the full electronic chain for a CMOS APS. The proposed model is validated against experimental data acquired with protons in an energy range relevant for pCT.

  10. The effects of nuclear data library processing on Geant4 and MCNP simulations of the thermal neutron scattering law

    Science.gov (United States)

    Hartling, K.; Ciungu, B.; Li, G.; Bentoumi, G.; Sur, B.

    2018-05-01

    Monte Carlo codes such as MCNP and Geant4 rely on a combination of physics models and evaluated nuclear data files (ENDF) to simulate the transport of neutrons through various materials and geometries. The grid representation used to represent the final-state scattering energies and angles associated with neutron scattering interactions can significantly affect the predictions of these codes. In particular, the default thermal scattering libraries used by MCNP6.1 and Geant4.10.3 do not accurately reproduce the ENDF/B-VII.1 model in simulations of the double-differential cross section for thermal neutrons interacting with hydrogen nuclei in a thin layer of water. However, agreement between model and simulation can be achieved within the statistical error by re-processing ENDF/B-VII.I thermal scattering libraries with the NJOY code. The structure of the thermal scattering libraries and sampling algorithms in MCNP and Geant4 are also reviewed.

  11. The study of response of wide band gap semiconductor detectors using the Geant4

    Directory of Open Access Journals (Sweden)

    Hussain Riaz

    2014-01-01

    Full Text Available The energy dependence on the intrinsic efficiency, absolute efficiency, full energy peak absolute efficiency and peak-to-total ratio have been studied for various wide band gap semiconductor detectors using the Geant4 based Monte Carlo simulations. The detector thickness of 1-4 mm and the area in 16-100 mm2 range were considered in this work. In excellent agreement with earlier work (Rybka et al., [20], the Geant4 simulated values of detector efficiencies have been found to decrease with incident g-ray energy. Both for the detector thickness and the detector area, the increasing trends have been observed for total efficiency as well as for full-energy peak efficiency in 0.1 MeV-50 MeV range. For Cd1-xZnxTe, the detector response remained insensitive to changes in relative proportions of Zn. For various wide band gap detectors studied in this work, the detection efficiency of TlBr was found highest over the entire range of energy, followed by the HgI2, CdTe, and then by CZT.

  12. Performance of Geant4 in simulating semiconductor particle detector response in the energy range below 1 MeV

    Science.gov (United States)

    Soti, G.; Wauters, F.; Breitenfeldt, M.; Finlay, P.; Kraev, I. S.; Knecht, A.; Porobić, T.; Zákoucký, D.; Severijns, N.

    2013-11-01

    Geant4 simulations play a crucial role in the analysis and interpretation of experiments providing low energy precision tests of the Standard Model. This paper focuses on the accuracy of the description of the electron processes in the energy range between 100 and 1000 keV. The effect of the different simulation parameters and multiple scattering models on the backscattering coefficients is investigated. Simulations of the response of HPGe and passivated implanted planar Si detectors to β particles are compared to experimental results. An overall good agreement is found between Geant4 simulations and experimental data.

  13. Proton and electron deep dose profiles for retinoblastoma based on GEANT 4 code

    International Nuclear Information System (INIS)

    Braga, Flavia V.; Campos, Tarcisio P.R. de; Ribeiro, Kilder L.

    2009-01-01

    Herein, the dosimetry responses to a retinoblastoma proton and electron radiation therapy were investigated. The computational tool applied to this simulation was the Geant4 code, version 4.9.1. The code allows simulating the charge particle interaction with eyeball tissue. In the present simulation, a box of 4 cm side water filled had represented the human eye. The simulation was performed considering mono energetic beams of protons and electrons with spectra of 57 to 70 MeV for protons and 2 to 8 MeV for electrons. The simulation was guide by the advanced hadron therapy example distributed with the Geant4 code. The phantom was divided in voxels with 0.2 mm side. The energy deposited in each voxel was evaluated taken the direct beam at one face. The simulation results show the delivery energy and therefore the dose deposited in each voxel. The deep dose profiles to proton and electron were plotted. The well known Bragg peak was reproduced for protons. The maximum delivered dose defined the position at the proton stopped. However, to electrons, the absorbed energies were delivered along its path producing a more continuous distribution following the water depth, but also being stopped in the end of its path. (author)

  14. Proton and electron deep dose profiles for retinoblastoma based on GEANT 4 code

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Flavia V., E-mail: flaviafisica@gmail.co [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares; Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Campos, Tarcisio P.R. de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares; Ribeiro, Kilder L., E-mail: kilderlr@gmail.co [Universidade Estadual de Feira de Santana (UEFS), BA (Brazil). Dept. de Fisica

    2009-07-01

    Herein, the dosimetry responses to a retinoblastoma proton and electron radiation therapy were investigated. The computational tool applied to this simulation was the Geant4 code, version 4.9.1. The code allows simulating the charge particle interaction with eyeball tissue. In the present simulation, a box of 4 cm side water filled had represented the human eye. The simulation was performed considering mono energetic beams of protons and electrons with spectra of 57 to 70 MeV for protons and 2 to 8 MeV for electrons. The simulation was guide by the advanced hadron therapy example distributed with the Geant4 code. The phantom was divided in voxels with 0.2 mm side. The energy deposited in each voxel was evaluated taken the direct beam at one face. The simulation results show the delivery energy and therefore the dose deposited in each voxel. The deep dose profiles to proton and electron were plotted. The well known Bragg peak was reproduced for protons. The maximum delivered dose defined the position at the proton stopped. However, to electrons, the absorbed energies were delivered along its path producing a more continuous distribution following the water depth, but also being stopped in the end of its path. (author)

  15. A Compton camera application for the GAMOS GEANT4-based framework

    Energy Technology Data Exchange (ETDEWEB)

    Harkness, L.J., E-mail: ljh@ns.ph.liv.ac.uk [Oliver Lodge Laboratory, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Arce, P. [Department of Basic Research, CIEMAT, Madrid (Spain); Judson, D.S.; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Dormand, J.; Jones, M.; Nolan, P.J.; Sampson, J.A.; Scraggs, D.P.; Sweeney, A. [Oliver Lodge Laboratory, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom)

    2012-04-11

    Compton camera systems can be used to image sources of gamma radiation in a variety of applications such as nuclear medicine, homeland security and nuclear decommissioning. To locate gamma-ray sources, a Compton camera employs electronic collimation, utilising Compton kinematics to reconstruct the paths of gamma rays which interact within the detectors. The main benefit of this technique is the ability to accurately identify and locate sources of gamma radiation within a wide field of view, vastly improving the efficiency and specificity over existing devices. Potential advantages of this imaging technique, along with advances in detector technology, have brought about a rapidly expanding area of research into the optimisation of Compton camera systems, which relies on significant input from Monte-Carlo simulations. In this paper, the functionality of a Compton camera application that has been integrated into GAMOS, the GEANT4-based Architecture for Medicine-Oriented Simulations, is described. The application simplifies the use of GEANT4 for Monte-Carlo investigations by employing a script based language and plug-in technology. To demonstrate the use of the Compton camera application, simulated data have been generated using the GAMOS application and acquired through experiment for a preliminary validation, using a Compton camera configured with double sided high purity germanium strip detectors. Energy spectra and reconstructed images for the data sets are presented.

  16. R and D on co-working transport schemes in Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Pia, M G; Saracco, P; Sudhakar, M [INFN Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Zoglauer, A [University of California at Berkeley, Berkeley, CA 94720-7450 (United States); Augelli, M [CNES, 18 Av. Edouard Belin, 31401 Toulouse (France); Gargioni, E [University Medical Center Hamburg-Eppendorf, D-20246 Hamburg (Germany); Kim, C H [Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul, 133-791 (Korea, Republic of); Quintieri, L [INFN Laboratori Nazionali di Frascati, Via Enrico Fermi 40, I-00044 Frascati (Italy); Filho, P P de Queiroz; Santos, D de Souza [IRD, Av. Salvador Allende, s/n. 22780-160, Rio de Janeiro, RJ (Brazil); Weidenspointner, G [MPI Halbleiterlabor, Otto-Hahn-Ring 6, D-81739 Muenchen (Germany); Begalli, M, E-mail: mariagrazia.pia@ge.infn.i [UERJ, R. Sao Francisco Xavier, 524. 20550-013, Rio de Janeiro, RJ (Brazil)

    2010-04-01

    A research and development (R and D) project related to the extension of the Geant4 toolkit has been recently launched to address fundamental methods in radiation transport simulation. The project focuses on simulation at different scales in the same experimental environment; this problem requires new methods across the current boundaries of condensed-random-walk and discrete transport schemes. The new developments have been motivated by experimental requirements in various domains, including nanodosimetry, astronomy and detector developments for high energy physics applications.

  17. Assessment of Geant4 Maintainability with respect to software engineering references

    Science.gov (United States)

    Ronchieri, Elisabetta; Grazia Pia, Maria; Canaparo, Marco

    2017-10-01

    Over time computer scientists have been provided metrics to measure software maintainability. In existing literature, a large number of references can be found about this topic; nevertheless, a lack of quantitative assessment of maintainability metrics has been observed. In this paper, we summarize the challenges of adopting code measurements in the context of physics software system. In this pilot study, we have used Geant4 - a twenty-year-old software system - to conduct this research and set the grounds for further discussion.

  18. Efficient voxel navigation for proton therapy dose calculation in TOPAS and Geant4

    Science.gov (United States)

    Schümann, J.; Paganetti, H.; Shin, J.; Faddegon, B.; Perl, J.

    2012-06-01

    A key task within all Monte Carlo particle transport codes is ‘navigation’, the calculation to determine at each particle step what volume the particle may be leaving and what volume the particle may be entering. Navigation should be optimized to the specific geometry at hand. For patient dose calculation, this geometry generally involves voxelized computed tomography (CT) data. We investigated the efficiency of navigation algorithms on currently available voxel geometry parameterizations in the Monte Carlo simulation package Geant4: G4VPVParameterisation, G4VNestedParameterisation and G4PhantomParameterisation, the last with and without boundary skipping, a method where neighboring voxels with the same Hounsfield unit are combined into one larger voxel. A fourth parameterization approach (MGHParameterization), developed in-house before the latter two parameterizations became available in Geant4, was also included in this study. All simulations were performed using TOPAS, a tool for particle simulations layered on top of Geant4. Runtime comparisons were made on three distinct patient CT data sets: a head and neck, a liver and a prostate patient. We included an additional version of these three patients where all voxels, including the air voxels outside of the patient, were uniformly set to water in the runtime study. The G4VPVParameterisation offers two optimization options. One option has a 60-150 times slower simulation speed. The other is compatible in speed but requires 15-19 times more memory compared to the other parameterizations. We found the average CPU time used for the simulation relative to G4VNestedParameterisation to be 1.014 for G4PhantomParameterisation without boundary skipping and 1.015 for MGHParameterization. The average runtime ratio for G4PhantomParameterisation with and without boundary skipping for our heterogeneous data was equal to 0.97: 1. The calculated dose distributions agreed with the reference distribution for all but the G4

  19. CPU time optimization and precise adjustment of the Geant4 physics parameters for a VARIAN 2100 C/D gamma radiotherapy linear accelerator simulation using GAMOS

    Science.gov (United States)

    Arce, Pedro; Lagares, Juan Ignacio

    2018-02-01

    We have verified the GAMOS/Geant4 simulation model of a 6 MV VARIAN Clinac 2100 C/D linear accelerator by the procedure of adjusting the initial beam parameters to fit the percentage depth dose and cross-profile dose experimental data at different depths in a water phantom. Thanks to the use of a wide range of field sizes, from 2  ×  2 cm2 to 40  ×  40 cm2, a small phantom voxel size and high statistics, fine precision in the determination of the beam parameters has been achieved. This precision has allowed us to make a thorough study of the different physics models and parameters that Geant4 offers. The three Geant4 electromagnetic physics sets of models, i.e. Standard, Livermore and Penelope, have been compared to the experiment, testing the four different models of angular bremsstrahlung distributions as well as the three available multiple-scattering models, and optimizing the most relevant Geant4 electromagnetic physics parameters. Before the fitting, a comprehensive CPU time optimization has been done, using several of the Geant4 efficiency improvement techniques plus a few more developed in GAMOS.

  20. An Overview of the Geant4 Toolkit

    CERN Document Server

    Apostolakis, John

    2007-01-01

    Geant4 is a toolkit for the simulation of the transport of radiation trough matter. With a flexible kernel and choices between different physics modeling choices, it has been tailored to the requirements of a wide range of applications. With the toolkit a user can describe a setup's or detector's geometry and materials, navigate inside it, simulate the physical interactions using a choice of physics engines, underlying physics cross-sections and models, visualise and store results. Physics models describing electromagnetic and hadronic interactions are provided, as are decays and processes for optical photons. Several models, with different precision and performance are available for many processes. The toolkit includes coherent physics model configurations, which are called physics lists. Users can choose an existing physics list or create their own, depending on their requirements and the application area. A clear structure and readable code, enable the user to investigate the origin of physics results. App...

  1. Estimation of the dose deposited by electron beams in radiotherapy in voxelised phantoms using the Monte Carlo simulation platform GATE based on GEANT4 in a grid environment

    International Nuclear Information System (INIS)

    Perrot, Y.

    2011-01-01

    Radiation therapy treatment planning requires accurate determination of absorbed dose in the patient. Monte Carlo simulation is the most accurate method for solving the transport problem of particles in matter. This thesis is the first study dealing with the validation of the Monte Carlo simulation platform GATE (GEANT4 Application for Tomographic Emission), based on GEANT4 (Geometry And Tracking) libraries, for the computation of absorbed dose deposited by electron beams. This thesis aims at demonstrating that GATE/GEANT4 calculations are able to reach treatment planning requirements in situations where analytical algorithms are not satisfactory. The goal is to prove that GATE/GEANT4 is useful for treatment planning using electrons and competes with well validated Monte Carlo codes. This is demonstrated by the simulations with GATE/GEANT4 of realistic electron beams and electron sources used for external radiation therapy or targeted radiation therapy. The computed absorbed dose distributions are in agreement with experimental measurements and/or calculations from other Monte Carlo codes. Furthermore, guidelines are proposed to fix the physics parameters of the GATE/GEANT4 simulations in order to ensure the accuracy of absorbed dose calculations according to radiation therapy requirements. (author)

  2. Simulation of Auger electron emission from nanometer-size gold targets using the Geant4 Monte Carlo simulation toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Incerti, S., E-mail: sebastien.incerti@tdt.edu.vn [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Suerfu, B.; Xu, J. [Department of Physics, Princeton University, Princeton, NJ (United States); Ivantchenko, V. [Ecoanalytica, Moscow (Russian Federation); Geant4 Associates International Ltd, Hebden Bridge (United Kingdom); Mantero, A. [SWHARD srl, via Greto di Cornigliano 6r, 16152 Genova (Italy); Brown, J.M.C. [School of Mathematics and Physics, Queen’s University Belfast, Belfast, Northern Ireland (United Kingdom); Bernal, M.A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, SP (Brazil); Francis, Z. [Université Saint Joseph, Faculty of Sciences, Department of Physics, Beirut (Lebanon); Karamitros, M. [Notre Dame Radiation Laboratory, University of Notre Dame, Notre Dame, IN (United States); Tran, H.N. [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam)

    2016-04-01

    A revised atomic deexcitation framework for the Geant4 general purpose Monte Carlo toolkit capable of simulating full Auger deexcitation cascades was implemented in June 2015 release (version 10.2 Beta). An overview of this refined framework and testing of its capabilities is presented for the irradiation of gold nanoparticles (NP) with keV photon and MeV proton beams. The resultant energy spectra of secondary particles created within and that escape the NP are analyzed and discussed. It is anticipated that this new functionality will improve and increase the use of Geant4 in the medical physics, radiobiology, nanomedicine research and other low energy physics fields.

  3. Monte carlo simulations of the n_TOF lead spallation target with the Geant4 toolkit: A benchmark study

    Directory of Open Access Journals (Sweden)

    Lerendegui-Marco J.

    2017-01-01

    Full Text Available Monte Carlo (MC simulations are an essential tool to determine fundamental features of a neutron beam, such as the neutron flux or the γ-ray background, that sometimes can not be measured or at least not in every position or energy range. Until recently, the most widely used MC codes in this field had been MCNPX and FLUKA. However, the Geant4 toolkit has also become a competitive code for the transport of neutrons after the development of the native Geant4 format for neutron data libraries, G4NDL. In this context, we present the Geant4 simulations of the neutron spallation target of the n_TOF facility at CERN, done with version 10.1.1 of the toolkit. The first goal was the validation of the intra-nuclear cascade models implemented in the code using, as benchmark, the characteristics of the neutron beam measured at the first experimental area (EAR1, especially the neutron flux and energy distribution, and the time distribution of neutrons of equal kinetic energy, the so-called Resolution Function. The second goal was the development of a Monte Carlo tool aimed to provide useful calculations for both the analysis and planning of the upcoming measurements at the new experimental area (EAR2 of the facility.

  4. Monte carlo simulations of the n_TOF lead spallation target with the Geant4 toolkit: A benchmark study

    Science.gov (United States)

    Lerendegui-Marco, J.; Cortés-Giraldo, M. A.; Guerrero, C.; Quesada, J. M.; Meo, S. Lo; Massimi, C.; Barbagallo, M.; Colonna, N.; Mancussi, D.; Mingrone, F.; Sabaté-Gilarte, M.; Vannini, G.; Vlachoudis, V.; Aberle, O.; Andrzejewski, J.; Audouin, L.; Bacak, M.; Balibrea, J.; Bečvář, F.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brown, A.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Cardella, R.; Casanovas, A.; Cerutti, F.; Chen, Y. H.; Chiaveri, E.; Cortés, G.; Cosentino, L.; Damone, L. A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Dupont, E.; Durán, I.; Fernández-Domínguez, B.; Ferrari, A.; Ferreira, P.; Finocchiaro, P.; Göbel, K.; Gómez-Hornillos, M. B.; García, A. R.; Gawlik, A.; Gilardoni, S.; Glodariu, T.; Gonçalves, I. F.; González, E.; Griesmayer, E.; Gunsing, F.; Harada, H.; Heinitz, S.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Käppeler, F.; Kadi, Y.; Kalamara, A.; Kavrigin, P.; Kimura, A.; Kivel, N.; Kokkoris, M.; Krtička, M.; Kurtulgil, D.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Lonsdale, S. J.; Macina, D.; Marganiec, J.; Martínez, T.; Masi, A.; Mastinu, P.; Mastromarco, M.; Maugeri, E. A.; Mazzone, A.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Musumarra, A.; Negret, A.; Nolte, R.; Oprea, A.; Patronis, N.; Pavlik, A.; Perkowski, J.; Porras, I.; Praena, J.; Radeck, D.; Rauscher, T.; Reifarth, R.; Rout, P. C.; Rubbia, C.; Ryan, J. A.; Saxena, A.; Schillebeeckx, P.; Schumann, D.; Smith, A. G.; Sosnin, N. V.; Stamatopoulos, A.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tassan-Got, L.; Valenta, S.; Variale, V.; Vaz, P.; Ventura, A.; Vlastou, R.; Wallner, A.; Warren, S.; Woods, P. J.; Wright, T.; Žugec, P.

    2017-09-01

    Monte Carlo (MC) simulations are an essential tool to determine fundamental features of a neutron beam, such as the neutron flux or the γ-ray background, that sometimes can not be measured or at least not in every position or energy range. Until recently, the most widely used MC codes in this field had been MCNPX and FLUKA. However, the Geant4 toolkit has also become a competitive code for the transport of neutrons after the development of the native Geant4 format for neutron data libraries, G4NDL. In this context, we present the Geant4 simulations of the neutron spallation target of the n_TOF facility at CERN, done with version 10.1.1 of the toolkit. The first goal was the validation of the intra-nuclear cascade models implemented in the code using, as benchmark, the characteristics of the neutron beam measured at the first experimental area (EAR1), especially the neutron flux and energy distribution, and the time distribution of neutrons of equal kinetic energy, the so-called Resolution Function. The second goal was the development of a Monte Carlo tool aimed to provide useful calculations for both the analysis and planning of the upcoming measurements at the new experimental area (EAR2) of the facility.

  5. Use of SRIM and Garfield with Geant4 for the characterization of a hybrid 10B/3He neutron detector

    Science.gov (United States)

    van der Ende, B. M.; Rand, E. T.; Erlandson, A.; Li, L.

    2018-06-01

    This paper describes a method for more complete neutron detector characterization using Geant4's Monte Carlo methods for characterizing overall detector response rate and Garfield interfaced with SRIM for the simulation of the detector's raw pulses, as applied to a hybrid 10B/3He detector. The Geant4 models characterizing the detector's interaction with a 252Cf point source and parallel beams of mono-energetic neutrons (assuming ISO 8529 reference energy values) compare and agree well with calibrated 252Cf measurements to within 6.4%. Validated Geant4 model outputs serve as input to Garfield+SRIM calculations to provide meaningful pulse height spectra. Modifications to Garfield for this work were necessary to account for simultaneous tracking of electrons resulting from proton and triton reaction products from a single 3He neutron capture event, and it was further necessary to interface Garfield with the energy loss, range, and straggling calculations provided by SRIM. Individual raw pulses generated by Garfield+SRIM are also observed to agree well with experimentally measured raw pulses from the detector.

  6. SU-E-T-521: Investigation of the Uncertainties Involved in Secondary Neutron/gamma Production in Geant4/MCNP6 Monte Carlo Codes for Proton Therapy Application

    International Nuclear Information System (INIS)

    Mirzakhanian, L; Enger, S; Giusti, V

    2015-01-01

    Purpose: A major concern in proton therapy is the production of secondary neutrons causing secondary cancers, especially in young adults and children. Most utilized Monte Carlo codes in proton therapy are Geant4 and MCNP. However, the default versions of Geant4 and MCNP6 do not have suitable cross sections or physical models to properly handle secondary particle production in proton energy ranges used for therapy. In this study, default versions of Geant4 and MCNP6 were modified to better handle production of secondaries by adding the TENDL-2012 cross-section library. Methods: In-water proton depth-dose was measured at the “The Svedberg Laboratory” in Uppsala (Sweden). The proton beam was mono-energetic with mean energy of 178.25±0.2 MeV. The measurement set-up was simulated by Geant4 version 10.00 (default and modified version) and MCNP6. Proton depth-dose, primary and secondary particle fluence and neutron equivalent dose were calculated. In case of Geant4, the secondary particle fluence was filtered by all the physics processes to identify the main process responsible for the difference between the default and modified version. Results: The proton depth-dose curves and primary proton fluence show a good agreement between both Geant4 versions and MCNP6. With respect to the modified version, default Geant4 underestimates the production of secondary neutrons while overestimates that of gammas. The “ProtonInElastic” process was identified as the main responsible process for the difference between the two versions. MCNP6 shows higher neutron production and lower gamma production than both Geant4 versions. Conclusion: Despite the good agreement on the proton depth dose curve and primary proton fluence, there is a significant discrepancy on secondary neutron production between MCNP6 and both versions of Geant4. Further studies are thus in order to find the possible cause of this discrepancy or more accurate cross-sections/models to handle the nuclear

  7. Comparison of GATE/GEANT4 with EGSnrc and MCNP for electron dose calculations at energies between 15 keV and 20 MeV.

    Science.gov (United States)

    Maigne, L; Perrot, Y; Schaart, D R; Donnarieix, D; Breton, V

    2011-02-07

    The GATE Monte Carlo simulation platform based on the GEANT4 toolkit has come into widespread use for simulating positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging devices. Here, we explore its use for calculating electron dose distributions in water. Mono-energetic electron dose point kernels and pencil beam kernels in water are calculated for different energies between 15 keV and 20 MeV by means of GATE 6.0, which makes use of the GEANT4 version 9.2 Standard Electromagnetic Physics Package. The results are compared to the well-validated codes EGSnrc and MCNP4C. It is shown that recent improvements made to the GEANT4/GATE software result in significantly better agreement with the other codes. We furthermore illustrate several issues of general interest to GATE and GEANT4 users who wish to perform accurate simulations involving electrons. Provided that the electron step size is sufficiently restricted, GATE 6.0 and EGSnrc dose point kernels are shown to agree to within less than 3% of the maximum dose between 50 keV and 4 MeV, while pencil beam kernels are found to agree to within less than 4% of the maximum dose between 15 keV and 20 MeV.

  8. Modeling of a cyclotron target for the production of 11C with Geant4.

    Science.gov (United States)

    Chiappiniello, Andrea; Zagni, Federico; Infantino, Angelo; Vichi, Sara; Cicoria, Gianfranco; Morigi, Maria Pia; Marengo, Mario

    2018-04-12

    In medical cyclotron facilities, 11C is produced according to the 14N(p,α)11C reaction and widely employed in studies of prostate and brain cancers by Positron Emission Tomography. It is known from literature [1] that the 11C-target assembly shows a reduction in efficiency during time, meaning a decrease of activity produced at the end of bombardment. This effect might depend on aspects still not completely known. Possible causes of the loss of performance of the 11C-target assembly were addressed by Monte Carlo simulations. Geant4 was used to model the 11C-target assembly of a GE PETtrace cyclotron. The physical and transport parameters to be used in the energy range of medical applications were extracted from literature data and 11C routine productions. The Monte Carlo assessment of 11C saturation yield was performed varying several parameters such as the proton energy and the angle of the target assembly with respect to the proton beam. The estimated 11C saturation yield is in agreement with IAEA data at the energy of interest, while is about the 35% greater than experimental value. A more comprehensive modeling of the target system, including thermodynamic effect, is required. The energy absorbed in the inner layer of the target chamber was up to 46.5 J/mm2 under typical irradiation conditions. This study shows that Geant4 is potentially a useful tool to design and optimize targetry for PET radionuclide productions. Tests to choose the Geant4 physics libraries should be performed before using this tool with different energies and materials. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. SU-E-T-347: Validation of the Condensed History Algorithm of Geant4 Using the Fano Test

    International Nuclear Information System (INIS)

    Lee, H; Mathis, M; Sawakuchi, G

    2014-01-01

    Purpose: To validate the condensed history algorithm and physics of the Geant4 Monte Carlo toolkit for simulations of ionization chambers (ICs). This study is the first step to validate Geant4 for calculations of photon beam quality correction factors under the presence of a strong magnetic field for magnetic resonance guided linac system applications. Methods: The electron transport and boundary crossing algorithms of Geant4 version 9.6.p02 were tested under Fano conditions using the Geant4 example/application FanoCavity. User-defined parameters of the condensed history and multiple scattering algorithms were investigated under Fano test conditions for three scattering models (physics lists): G4UrbanMscModel95 (PhysListEmStandard-option3), G4GoudsmitSaundersonMsc (PhysListEmStandard-GS), and G4WentzelVIModel/G4CoulombScattering (PhysListEmStandard-WVI). Simulations were conducted using monoenergetic photon beams, ranging from 0.5 to 7 MeV and emphasizing energies from 0.8 to 3 MeV. Results: The GS and WVI physics lists provided consistent Fano test results (within ±0.5%) for maximum step sizes under 0.01 mm at 1.25 MeV, with improved performance at 3 MeV (within ±0.25%). The option3 physics list provided consistent Fano test results (within ±0.5%) for maximum step sizes above 1 mm. Optimal parameters for the option3 physics list were 10 km maximum step size with default values for other user-defined parameters: 0.2 dRoverRange, 0.01 mm final range, 0.04 range factor, 2.5 geometrical factor, and 1 skin. Simulations using the option3 physics list were ∼70 – 100 times faster compared to GS and WVI under optimal parameters. Conclusion: This work indicated that the option3 physics list passes the Fano test within ±0.5% when using a maximum step size of 10 km for energies suitable for IC calculations in a 6 MV spectrum without extensive computational times. Optimal user-defined parameters using the option3 physics list will be used in future IC simulations to

  10. BRDF profile of Tyvek and its implementation in the Geant4 simulation toolkit.

    Science.gov (United States)

    Nozka, Libor; Pech, Miroslav; Hiklova, Helena; Mandat, Dusan; Hrabovsky, Miroslav; Schovanek, Petr; Palatka, Miroslav

    2011-02-28

    Diffuse and specular characteristics of the Tyvek 1025-BL material are reported with respect to their implementation in the Geant4 Monte Carlo simulation toolkit. This toolkit incorporates the UNIFIED model. Coefficients defined by the UNIFIED model were calculated from the bidirectional reflectance distribution function (BRDF) profiles measured with a scatterometer for several angles of incidence. Results were amended with profile measurements made by a profilometer.

  11. Comparison of the thermal neutron scattering treatment in MCNP6 and GEANT4 codes

    Science.gov (United States)

    Tran, H. N.; Marchix, A.; Letourneau, A.; Darpentigny, J.; Menelle, A.; Ott, F.; Schwindling, J.; Chauvin, N.

    2018-06-01

    To ensure the reliability of simulation tools, verification and comparison should be made regularly. This paper describes the work performed in order to compare the neutron transport treatment in MCNP6.1 and GEANT4-10.3 in the thermal energy range. This work focuses on the thermal neutron scattering processes for several potential materials which would be involved in the neutron source designs of Compact Accelerator-based Neutrons Sources (CANS), such as beryllium metal, beryllium oxide, polyethylene, graphite, para-hydrogen, light water, heavy water, aluminium and iron. Both thermal scattering law and free gas model, coming from the evaluated data library ENDF/B-VII, were considered. It was observed that the GEANT4.10.03-patch2 version was not able to account properly the coherent elastic process occurring in crystal lattice. This bug is treated in this work and it should be included in the next release of the code. Cross section sampling and integral tests have been performed for both simulation codes showing a fair agreement between the two codes for most of the materials except for iron and aluminium.

  12. Automatic modeling for the Monte Carlo transport code Geant4 in MCAM

    International Nuclear Information System (INIS)

    Nie Fanzhi; Hu Liqin; Wang Guozhong; Wang Dianxi; Wu Yican; Wang Dong; Long Pengcheng; FDS Team

    2014-01-01

    Geant4 is a widely used Monte Carlo transport simulation package. Its geometry models could be described in geometry description markup language (GDML), but it is time-consuming and error-prone to describe the geometry models manually. This study implemented the conversion between computer-aided design (CAD) geometry models and GDML models. The conversion program was integrated into Multi-Physics Coupling Analysis Modeling Program (MCAM). The tests, including FDS-Ⅱ model, demonstrated its accuracy and feasibility. (authors)

  13. Comparison of electromagnetic and hadronic models generated using Geant 4 with antiproton dose measured in CERN.

    Science.gov (United States)

    Tavakoli, Mohammad Bagher; Reiazi, Reza; Mohammadi, Mohammad Mehdi; Jabbari, Keyvan

    2015-01-01

    After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.

  14. A COMPUTER CLUSTER SYSTEM FOR PSEUDO-PARALLEL EXECUTION OF GEANT4 SERIAL APPLICATION

    Directory of Open Access Journals (Sweden)

    Memmo Federici

    2013-12-01

    Full Text Available Simulation of the interactions between particles and matter in studies for developing X-rays detectors generally requires very long calculation times (up to several days or weeks. These times are often a serious limitation for the success of the simulations and for the accuracy of the simulated models. One of the tools used by the scientific community to perform these simulations is Geant4 (Geometry And Tracking [2, 3]. On the best of experience in the design of the AVES cluster computing system, Federici et al. [1], the IAPS (Istituto di Astrofisica e Planetologia Spaziali INAF laboratories were able to develop a cluster computer system dedicated to Geant 4. The Cluster is easy to use and easily expandable, and thanks to the design criteria adopted it achieves an excellent compromise between performance and cost. The management software developed for the Cluster splits the single instance of simulation on the cores available, allowing the use of software written for serial computation to reach a computing speed similar to that obtainable from a native parallel software. The simulations carried out on the Cluster showed an increase in execution time by a factor of 20 to 60 compared to the times obtained with the use of a single PC of medium quality.

  15. Progress and Validation of Geant4 Based Radioactive Decay Simulation Using the Examples of Simbol-X and IXO

    CERN Document Server

    Hauf, S; Pia, M G; Bell, Z; Briel, U; Chipaux, R; Hoffmann, D H H; Kendziorra, E; Laurent, P; Strüder, L; Tenzer, C; Weidenspointer, G; Zoglauer, A

    2009-01-01

    The anticipated high sensitivity and the science goals of the next generation X-ray space missions, like the International X-ray Observatory or Simbol-X, rely on a low instrumental background, which in turn requires optimized shielding concepts. We present Geant4 based simulation results on the IXO Wide Field Imager cosmic ray proton induced background in comparison with previous results obtained for the Simbol-X LED and HED focal plane detectors. Our results show that an improvement in mean differential background flux compared to actually operating X-ray observatories may be feasible with detectors based on DEPFET technology. In addition we present preliminary results concerning the validation of Geant4 based radioactive decay simulation in space applications as a part of the Nano5 project.

  16. Gamma-gamma density and lithology tools simulation based on GEANT4 advanced low energy Compton scattering (GALECS) package

    International Nuclear Information System (INIS)

    Esmaeili-sani, Vahid; Moussavi-zarandi, Ali; Boghrati, Behzad; Afarideh, Hossein

    2012-01-01

    Geophysical bore-hole data represent the physical properties of rocks, such as density and formation lithology, as a function of depth in a well. Properties of rocks are obtained from gamma ray transport logs. Transport of gamma rays, from a 137 Cs point gamma source situated in a bore-hole tool, through rock media to detectors, has been simulated using a GEANT4 radiation transport code. The advanced Compton scattering concepts were used to gain better analyses about well formation. The simulation and understanding of advanced Compton scattering highly depends on how accurately the effects of Doppler broadening and Rayleigh scattering are taken into account. A Monte Carlo package that simulates the gamma-gamma well logging tools based on GEANT4 advanced low energy Compton scattering (GALECS).

  17. Nuclear fragmentation reactions in extended media studied with Geant4 toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Pshenichnov, Igor, E-mail: pshenich@fias.uni-frankfurt.d [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); Institute for Nuclear Research, Russian Academy of Science, 117312 Moscow (Russian Federation); Botvina, Alexander [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); Institute for Nuclear Research, Russian Academy of Science, 117312 Moscow (Russian Federation); Mishustin, Igor [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); Kurchatov Institute, Russian Research Center, 123182 Moscow (Russian Federation); Greiner, Walter [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany)

    2010-03-15

    It is well-known from numerous experiments that nuclear multifragmentation is a dominating mechanism for production of intermediate mass fragments in nucleus-nucleus collisions at energies above 100AMeV. In this paper we investigate the validity and performance of the Fermi break-up model and the statistical multifragmentation model implemented as parts of the Geant4 toolkit. We study the impact of violent nuclear disintegration reactions on the depth-dose profiles and yields of secondary fragments for beams of light and medium-weight nuclei propagating in extended media. Implications for ion-beam cancer therapy and shielding from cosmic radiation are discussed.

  18. Nuclear fragmentation reactions in extended media studied with Geant4 toolkit

    International Nuclear Information System (INIS)

    Pshenichnov, Igor; Botvina, Alexander; Mishustin, Igor; Greiner, Walter

    2010-01-01

    It is well-known from numerous experiments that nuclear multifragmentation is a dominating mechanism for production of intermediate mass fragments in nucleus-nucleus collisions at energies above 100AMeV. In this paper we investigate the validity and performance of the Fermi break-up model and the statistical multifragmentation model implemented as parts of the Geant4 toolkit. We study the impact of violent nuclear disintegration reactions on the depth-dose profiles and yields of secondary fragments for beams of light and medium-weight nuclei propagating in extended media. Implications for ion-beam cancer therapy and shielding from cosmic radiation are discussed.

  19. Nuclear spectroscopy with Geant4: Proton and neutron emission & radioactivity

    Science.gov (United States)

    Sarmiento, L. G.; Rudolph, D.

    2016-07-01

    With the aid of a novel combination of existing equipment - JYFLTRAP and the TASISpec decay station - it is possible to perform very clean quantum-state selective, high-resolution particle-γ decay spectroscopy. We intend to study the determination of the branching ratio of the ℓ = 9 proton emission from the Iπ = 19/2-, 3174-keV isomer in the N = Z - 1 nucleus 53Co. The study aims to initiate a series of similar experiments along the proton dripline, thereby providing unique insights into "open quantum systems". The technique has been pioneered in case studies using SHIPTRAP and TASISpec at GSI. Newly available radioactive decay modes in Geant4 simulations are going to corroborate the anticipated experimental results.

  20. Geant4.10 simulation of geometric model for metaphase chromosome

    Energy Technology Data Exchange (ETDEWEB)

    Rafat-Motavalli, L., E-mail: rafat@um.ac.ir; Miri-Hakimabad, H.; Bakhtiyari, E.

    2016-04-01

    In this paper, a geometric model of metaphase chromosome is explained. The model is constructed according to the packing ratio and dimension of the structure from nucleosome up to chromosome. A B-DNA base pair is used to construct 200 base pairs of nucleosomes. Each chromatin fiber loop, which is the unit of repeat, has 49,200 bp. This geometry is entered in Geant4.10 Monte Carlo simulation toolkit and can be extended to the whole metaphase chromosomes and any application in which a DNA geometrical model is needed. The chromosome base pairs, chromosome length, and relative length of chromosomes are calculated. The calculated relative length is compared to the relative length of human chromosomes.

  1. Geant4.10 simulation of geometric model for metaphase chromosome

    International Nuclear Information System (INIS)

    Rafat-Motavalli, L.; Miri-Hakimabad, H.; Bakhtiyari, E.

    2016-01-01

    In this paper, a geometric model of metaphase chromosome is explained. The model is constructed according to the packing ratio and dimension of the structure from nucleosome up to chromosome. A B-DNA base pair is used to construct 200 base pairs of nucleosomes. Each chromatin fiber loop, which is the unit of repeat, has 49,200 bp. This geometry is entered in Geant4.10 Monte Carlo simulation toolkit and can be extended to the whole metaphase chromosomes and any application in which a DNA geometrical model is needed. The chromosome base pairs, chromosome length, and relative length of chromosomes are calculated. The calculated relative length is compared to the relative length of human chromosomes.

  2. SU-E-T-05: Comparing DNA Strand Break Yields for Photons under Different Irradiation Conditions with Geant4-DNA.

    Science.gov (United States)

    Pater, P; Bernal, M; Naqa, I El; Seuntjens, J

    2012-06-01

    To validate and scrutinize published DNA strand break data with Geant4-DNA and a probabilistic model. To study the impact of source size, electronic equilibrium and secondary electron tracking cutoff on direct relative biological effectiveness (DRBE). Geant4 (v4.9.5) was used to simulate a cylindrical region of interest (ROI) with r = 15 nm and length = 1.05 mm, in a slab of liquid water of 1.06 g/cm 3 density. The ROI was irradiated with mono-energetic photons, with a uniformly distributed volumetric isotropic source (0.28, 1.5 keV) or a plane beam (0.662, 1.25 MeV), of variable size. Electrons were tracked down to 50 or 10 eV, with G4-DNA processes and energy transfer greater than 10.79 eV was scored. Based on volume ratios, each scored event had a 0.0388 probability of happening on either DNA helix (break). Clusters of at least one break on each DNA helix within 3.4 nm were found using a DBSCAN algorithm and categorized as double strand breaks (DSB). All other events were categorized as single strand breaks (SSB). Geant4-DNA is able to reproduce strand break yields previously published. Homogeneous irradiation conditions should be present throughout the ROI for DRBE comparisons. SSB yields seem slightly dependent on the primary photon energy. DRBEs show a significant increasing trend for lower energy incident photons. A lower electron cutoff produces higher SSB yields, but decreases the SSB/DSB yields ratio. The probabilistic and geometrical DNA models can predict equivalent results. Using Geant4, we were able to reproduce previously published results on the direct strand break yields of photon and study the importance of irradiation conditions. We also show an ascending trend for DRBE with lower incident photon energies. A probabilistic model coupled with track structure analysis can be used to simulate strand break yields. NSERC, CIHR. © 2012 American Association of Physicists in Medicine.

  3. Geant4 simulations on Compton scattering of laser photons on relativistic electrons

    Energy Technology Data Exchange (ETDEWEB)

    Filipescu, D. [Extreme Light Infrastructure - Nuclear Physics, str. Atomistilor nr. 407, Bucharest-Magurele, P.O.BOX MG6, Romania and National Institute for Physics and Nuclear Engineering Horia Hulubei, str. Atomistilor nr. 407 (Romania); Utsunomiya, H. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan); Gheorghe, I.; Glodariu, T. [National Institute for Physics and Nuclear Engineering Horia Hulubei, str. Atomistilor nr. 407 (Romania); Tesileanu, O. [Extreme Light Infrastructure - Nuclear Physics, str. Atomistilor nr. 407, Bucharest-Magurele, P.O.BOX MG6 (Romania); Shima, T.; Takahisa, K. [Research Center for Nuclear Physics, Osaka University, Suita, Osaka 567-0047 (Japan); Miyamoto, S. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigori, Hyogo 678-1205 (Japan)

    2015-02-24

    Using Geant4, a complex simulation code of the interaction between laser photons and relativistic electrons was developed. We implemented physically constrained electron beam emittance and spacial distribution parameters and we also considered a Gaussian laser beam. The code was tested against experimental data produced at the γ-ray beam line GACKO (Gamma Collaboration Hutch of Konan University) of the synchrotron radiation facility NewSUBARU. Here we will discuss the implications of transverse missallignments of the collimation system relative to the electron beam axis.

  4. Comparative analysis of the sensitivity of the scanner rSPECT: using GAMOS: a Geant4-based framework

    International Nuclear Information System (INIS)

    Martinez Turtos, Rosana; Diaz Garcia, Angelina; Abreu Alfonso, Yamiel; Arteche, Jossue; Leyva Pernia, Diana

    2012-01-01

    The molecular imaging of cellular processes in vivo using preclinical animal studies and SPECT technique is one of the main reasons for the design of new devices with high spatial resolution. As an auxiliary tool, Monte Carlo simulation has allowed the characterization and optimization of those medical imaging systems effectively. At present there is a new simulation framework called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations); which code, libraries and particle transport method correspond to those developed by GEANT4 and contains specific applications for nuclear medicine. This tool has been already validated for PET technique by comparison with experimental data, while not yet been done the correct evaluation of GAMOS for SPECT systems. Present work have demonstrated the potential of GAMOS in obtaining simulated realistic data using this nuclear imaging technique. For this purpose, simulation of a novel installation 'rSPECT' ,dedicated to the study of rodents, has been done. The study comprises the collimation and detection geometries and the fundamental characteristics of the previous published experimental measurements for rSPECT installation. Studies have been done using 99mTc and 20% energy window. Sensitivity values obtained by simulation revealed an acceptable agreement with experimental values. Therefore we can conclude that simulation results have shown good agreement with the real data. This fact allowed to estimate the behavior of the new GEANT4 simulation platform 'GAMOS' in SPECT applications and have demonstrated the feasibility of reproducing experimental data. (author)

  5. SU-E-T-531: Performance Evaluation of Multithreaded Geant4 for Proton Therapy Dose Calculations in a High Performance Computing Facility

    International Nuclear Information System (INIS)

    Shin, J; Coss, D; McMurry, J; Farr, J; Faddegon, B

    2014-01-01

    Purpose: To evaluate the efficiency of multithreaded Geant4 (Geant4-MT, version 10.0) for proton Monte Carlo dose calculations using a high performance computing facility. Methods: Geant4-MT was used to calculate 3D dose distributions in 1×1×1 mm3 voxels in a water phantom and patient's head with a 150 MeV proton beam covering approximately 5×5 cm2 in the water phantom. Three timestamps were measured on the fly to separately analyze the required time for initialization (which cannot be parallelized), processing time of individual threads, and completion time. Scalability of averaged processing time per thread was calculated as a function of thread number (1, 100, 150, and 200) for both 1M and 50 M histories. The total memory usage was recorded. Results: Simulations with 50 M histories were fastest with 100 threads, taking approximately 1.3 hours and 6 hours for the water phantom and the CT data, respectively with better than 1.0 % statistical uncertainty. The calculations show 1/N scalability in the event loops for both cases. The gains from parallel calculations started to decrease with 150 threads. The memory usage increases linearly with number of threads. No critical failures were observed during the simulations. Conclusion: Multithreading in Geant4-MT decreased simulation time in proton dose distribution calculations by a factor of 64 and 54 at a near optimal 100 threads for water phantom and patient's data respectively. Further simulations will be done to determine the efficiency at the optimal thread number. Considering the trend of computer architecture development, utilizing Geant4-MT for radiotherapy simulations is an excellent cost-effective alternative for a distributed batch queuing system. However, because the scalability depends highly on simulation details, i.e., the ratio of the processing time of one event versus waiting time to access for the shared event queue, a performance evaluation as described is recommended

  6. Influence of thyroid volume reduction on absorbed dose in "1"3"1I therapy studied by using Geant4 Monte Carlo simulation

    International Nuclear Information System (INIS)

    Rahman, Ziaur; Arshed, Waheed; Ahmed, Waheed; Mirza, Sikander M.; Mirza, Nasir M.

    2014-01-01

    A simulation study has been performed to quantify the effect of volume reduction on the thyroid absorbed dose per decay and to investigate the variation of energy deposition per decay due to β- and γ-activity of "1"3"1I with volume/mass of thyroid, for water, ICRP- and ICRU-soft tissue taken as thyroid material. A Monte Carlo model of the thyroid, in the Geant4 radiation transport simulation toolkit was constructed to compute the β- and γ-absorbed dose in the simulated thyroid phantom for various values of its volume. The effect of the size and shape of the thyroid on energy deposition per decay has also been studied by using spherical, ellipsoidal and cylindrical models for the thyroid and varying its volume in 1-25 cm"3 range. The relative differences of Geant4 results for different models with each other and MCNP results lie well below 1.870%. The maximum relative difference among the Geant4 estimated results for water with ICRP and ICRU soft tissues is not more than 0.225%. S-values for ellipsoidal, spherical and cylindrical thyroid models were estimated and the relative difference with published results lies within 3.095%. The absorbed fraction values for beta particles show a good agreement with published values within 2.105% deviation. The Geant4 based simulation results of absorbed fractions for gammas again show a good agreement with the corresponding MCNP and EGS4 results (± 6.667%) but have 29.032% higher values than that of MIRD calculated values. Consistent with previous studies, the reduction of the thyroid volume is found to have a substantial effect on the absorbed dose. Geant4 simulations confirm dose dependence on the volume/mass of thyroid in agreement with MCNP and EGS4 computed values but are substantially different from MIRD8 data. Therefore, inclusion of size/mass dependence is indicated for "1"3"1I radiotherapy of the thyroid. (authors)

  7. Monte Carlo simulation and scatter correction of the GE Advance PET scanner with SimSET and Geant4

    International Nuclear Information System (INIS)

    Barret, Olivier; Carpenter, T Adrian; Clark, John C; Ansorge, Richard E; Fryer, Tim D

    2005-01-01

    For Monte Carlo simulations to be used as an alternative solution to perform scatter correction, accurate modelling of the scanner as well as speed is paramount. General-purpose Monte Carlo packages (Geant4, EGS, MCNP) allow a detailed description of the scanner but are not efficient at simulating voxel-based geometries (patient images). On the other hand, dedicated codes (SimSET, PETSIM) will perform well for voxel-based objects but will be poor in their capacity of simulating complex geometries such as a PET scanner. The approach adopted in this work was to couple a dedicated code (SimSET) with a general-purpose package (Geant4) to have the efficiency of the former and the capabilities of the latter. The combined SimSET+Geant4 code (SimG4) was assessed on the GE Advance PET scanner and compared to the use of SimSET only. A better description of the resolution and sensitivity of the scanner and of the scatter fraction was obtained with SimG4. The accuracy of scatter correction performed with SimG4 and SimSET was also assessed from data acquired with the 20 cm NEMA phantom. SimG4 was found to outperform SimSET and to give slightly better results than the GE scatter correction methods installed on the Advance scanner (curve fitting and scatter modelling for the 300-650 keV and 375-650 keV energy windows, respectively). In the presence of a hot source close to the edge of the field of view (as found in oxygen scans), the GE curve-fitting method was found to fail whereas SimG4 maintained its performance

  8. Validation of the coupling of mesh models to GEANT4 Monte Carlo code for simulation of internal sources of photons

    International Nuclear Information System (INIS)

    Caribe, Paulo Rauli Rafeson Vasconcelos; Cassola, Vagner Ferreira; Kramer, Richard; Khoury, Helen Jamil

    2013-01-01

    The use of three-dimensional models described by polygonal meshes in numerical dosimetry enables more accurate modeling of complex objects than the use of simple solid. The objectives of this work were validate the coupling of mesh models to the Monte Carlo code GEANT4 and evaluate the influence of the number of vertices in the simulations to obtain absorbed fractions of energy (AFEs). Validation of the coupling was performed to internal sources of photons with energies between 10 keV and 1 MeV for spherical geometries described by the GEANT4 and three-dimensional models with different number of vertices and triangular or quadrilateral faces modeled using Blender program. As a result it was found that there were no significant differences between AFEs for objects described by mesh models and objects described using solid volumes of GEANT4. Since that maintained the shape and the volume the decrease in the number of vertices to describe an object does not influence so meant dosimetric data, but significantly decreases the time required to achieve the dosimetric calculations, especially for energies less than 100 keV

  9. NEUTRON GENERATOR FACILITY AT SFU: GEANT4 DOSE RATE PREDICTION AND VERIFICATION.

    Science.gov (United States)

    Williams, J; Chester, A; Domingo, T; Rizwan, U; Starosta, K; Voss, P

    2016-11-01

    Detailed dose rate maps for a neutron generator facility at Simon Fraser University were produced via the GEANT4 Monte Carlo framework. Predicted neutron dose rates throughout the facility were compared with radiation survey measurements made during the facility commissioning process. When accounting for thermal neutrons, the prediction and measurement agree within a factor of 2 or better in most survey locations, and within 10 % inside the vault housing the neutron generator. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Diffusion-controlled reactions modeling in Geant4-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Karamitros, M., E-mail: matkara@gmail.com [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, INCIA, UMR 5287, F-33400 Talence (France); Luan, S. [University of New Mexico, Department of Computer Science, Albuquerque, NM (United States); Bernal, M.A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, SP (Brazil); Allison, J. [Geant4 Associates International Ltd (United Kingdom); Baldacchino, G. [CEA Saclay, IRAMIS, LIDYL, Radiation Physical Chemistry Group, F-91191 Gif sur Yvette Cedex (France); CNRS, UMR3299, SIS2M, F-91191 Gif sur Yvette Cedex (France); Davidkova, M. [Nuclear Physics Institute of the ASCR, Prague (Czech Republic); Francis, Z. [Saint Joseph University, Faculty of Sciences, Department of Physics, Mkalles, Beirut (Lebanon); Friedland, W. [Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg (Germany); Ivantchenko, V. [Ecoanalytica, 119899 Moscow (Russian Federation); Geant4 Associates International Ltd (United Kingdom); Ivantchenko, A. [Geant4 Associates International Ltd (United Kingdom); Mantero, A. [SwHaRD s.r.l., via Buccari 9, 16153 Genova (Italy); Nieminem, P.; Santin, G. [ESA-ESTEC, 2200 AG Noordwijk (Netherlands); Tran, H.N. [Division of Nuclear Physics and Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Stepan, V. [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Nuclear Physics Institute of the ASCR, Prague (Czech Republic); Incerti, S., E-mail: incerti@cenbg.in2p3.fr [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France)

    2014-10-01

    Context Under irradiation, a biological system undergoes a cascade of chemical reactions that can lead to an alteration of its normal operation. There are different types of radiation and many competing reactions. As a result the kinetics of chemical species is extremely complex. The simulation becomes then a powerful tool which, by describing the basic principles of chemical reactions, can reveal the dynamics of the macroscopic system. To understand the dynamics of biological systems under radiation, since the 80s there have been on-going efforts carried out by several research groups to establish a mechanistic model that consists in describing all the physical, chemical and biological phenomena following the irradiation of single cells. This approach is generally divided into a succession of stages that follow each other in time: (1) the physical stage, where the ionizing particles interact directly with the biological material; (2) the physico-chemical stage, where the targeted molecules release their energy by dissociating, creating new chemical species; (3) the chemical stage, where the new chemical species interact with each other or with the biomolecules; (4) the biological stage, where the repairing mechanisms of the cell come into play. This article focuses on the modeling of the chemical stage. Method This article presents a general method of speeding-up chemical reaction simulations in fluids based on the Smoluchowski equation and Monte-Carlo methods, where all molecules are explicitly simulated and the solvent is treated as a continuum. The model describes diffusion-controlled reactions. This method has been implemented in Geant4-DNA. The keys to the new algorithm include: (1) the combination of a method to compute time steps dynamically with a Brownian bridge process to account for chemical reactions, which avoids costly fixed time step simulations; (2) a k–d tree data structure for quickly locating, for a given molecule, its closest reactants. The

  11. Behaviors of the percentage depth dose curves along the beam axis of a phantom filled with different clinical PTO objects, a Monte Carlo Geant4 study

    International Nuclear Information System (INIS)

    EL Bakkali, Jaafar; EL Bardouni, Tarek; Safavi, Seyedmostafa; Mohammed, Maged; Saeed, Mroan

    2016-01-01

    The aim of this work is to assess the capabilities of Monte Carlo Geant4 code to reproduce the real percentage depth dose (PDD) curves generated in phantoms which mimic three important clinical treatment situations that include lung slab, bone slab, bone-lung slab geometries. It is hoped that this work will lead us to a better understanding of dose distributions in an inhomogeneous medium, and to identify any limitations of dose calculation algorithm implemented in the Geant4 code. For this purpose, the PDD dosimetric functions associated to the three clinical situations described above, were compared to one produced in a homogeneous water phantom. Our results show, firstly, that the Geant4 simulation shows potential mistakes on the shape of the calculated PDD curve of the first physical test object (PTO), and it is obviously not able to successfully predict dose values in regions near to the boundaries between two different materials. This is, surely due to the electron transport algorithm and it is well-known as the artifacts at interface phenomenon. To deal with this issue, we have added and optimized the StepMax parameter to the dose calculation program; consequently the artifacts due to the electron transport were quasi disappeared. However, the Geant4 simulation becomes painfully slow when we attempt to completely resolve the electron artifact problems by considering a smaller value of an electron StepMax parameter. After electron transport optimization, our results demonstrate the medium-level capabilities of the Geant4 code to modeling dose distribution in clinical PTO objects. - Highlights: • Assessment of the capabilities of Geant4 code to reproduce the PDD curves in heterogeneities. • Resolving artifacts due to the electron transport. • Understanding in dose distribution differences in interfaces which include water, bone, and lung interfaces.

  12. Gamma-gamma density and lithology tools simulation based on GEANT4 advanced low energy Compton scattering (GALECS) package

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeili-sani, Vahid, E-mail: vaheed_esmaeely80@yahoo.com [Department of Nuclear Engineering and Physics, Amirkabir University of Technology, P.O. Box 4155-4494, Tehran (Iran, Islamic Republic of); Moussavi-zarandi, Ali; Boghrati, Behzad; Afarideh, Hossein [Department of Nuclear Engineering and Physics, Amirkabir University of Technology, P.O. Box 4155-4494, Tehran (Iran, Islamic Republic of)

    2012-02-01

    Geophysical bore-hole data represent the physical properties of rocks, such as density and formation lithology, as a function of depth in a well. Properties of rocks are obtained from gamma ray transport logs. Transport of gamma rays, from a {sup 137}Cs point gamma source situated in a bore-hole tool, through rock media to detectors, has been simulated using a GEANT4 radiation transport code. The advanced Compton scattering concepts were used to gain better analyses about well formation. The simulation and understanding of advanced Compton scattering highly depends on how accurately the effects of Doppler broadening and Rayleigh scattering are taken into account. A Monte Carlo package that simulates the gamma-gamma well logging tools based on GEANT4 advanced low energy Compton scattering (GALECS).

  13. An Overview of the GEANT4 Toolkit

    International Nuclear Information System (INIS)

    Apostolakis, John; CERN; Wright, Dennis H.

    2007-01-01

    Geant4 is a toolkit for the simulation of the transport of radiation through matter. With a flexible kernel and choices between different physics modeling choices, it has been tailored to the requirements of a wide range of applications. With the toolkit a user can describe a setup's or detector's geometry and materials, navigate inside it, simulate the physical interactions using a choice of physics engines, underlying physics cross-sections and models, visualize and store results. Physics models describing electromagnetic and hadronic interactions are provided, as are decays and processes for optical photons. Several models, with different precision and performance are available for many processes. The toolkit includes coherent physics model configurations, which are called physics lists. Users can choose an existing physics list or create their own, depending on their requirements and the application area. A clear structure and readable code, enable the user to investigate the origin of physics results. Application areas include detector simulation and background simulation in High Energy Physics experiments, simulation of accelerator setups, studies in medical imaging and treatment, and the study of the effects of solar radiation on spacecraft instruments

  14. CLIC Detector Concepts as described in the CDR: Differences between the GEANT4 and Engineering Models

    CERN Document Server

    Elsener, K; Schlatter, D; Siegrist, N

    2011-01-01

    The CLIC_ILD and CLIC_SiD detector concepts as used for the CDR Vol. 2 in 2011 exist both in GEANT4 simulation models and in engineering layout drawings. At this early stage of a conceptual design, there are inevitably differences between these models, which are described in this note.

  15. Geant4 simulation of a 3D high resolution gamma camera

    International Nuclear Information System (INIS)

    Akhdar, H.; Kezzar, K.; Aksouh, F.; Assemi, N.; AlGhamdi, S.; AlGarawi, M.; Gerl, J.

    2015-01-01

    The aim of this work is to develop a 3D gamma camera with high position resolution and sensitivity relying on both distance/absorption and Compton scattering techniques and without using any passive collimation. The proposed gamma camera is simulated in order to predict its performance using the full benefit of Geant4 features that allow the construction of the needed geometry of the detectors, have full control of the incident gamma particles and study the response of the detector in order to test the suggested geometries. Three different geometries are simulated and each configuration is tested with three different scintillation materials (LaBr3, LYSO and CeBr3)

  16. Nuclear spectroscopy with Geant4: Proton and neutron emission & radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento, L. G., E-mail: Luis.Sarmiento@nuclear.lu.se; Rudolph, D. [Department of Physics, Lund University, 22100 Lund (Sweden)

    2016-07-07

    With the aid of a novel combination of existing equipment – JYFLTRAP and the TASISpec decay station – it is possible to perform very clean quantum-state selective, high-resolution particle-γ decay spectroscopy. We intend to study the determination of the branching ratio of the ℓ = 9 proton emission from the I{sup π} = 19/2{sup −}, 3174-keV isomer in the N = Z − 1 nucleus {sup 53}Co. The study aims to initiate a series of similar experiments along the proton dripline, thereby providing unique insights into “open quantum systems”. The technique has been pioneered in case studies using SHIPTRAP and TASISpec at GSI. Newly available radioactive decay modes in Geant4 simulations are going to corroborate the anticipated experimental results.

  17. A Geant4 evaluation of the Hornyak button and two candidate detectors for the TREAT hodoscope

    Science.gov (United States)

    Fu, Wenkai; Ghosh, Priyarshini; Harrison, Mark J.; McGregor, Douglas S.; Roberts, Jeremy A.

    2018-05-01

    The performance of traditional Hornyak buttons and two proposed variants for fast-neutron hodoscope applications was evaluated using Geant4. The Hornyak button is a ZnS(Ag)-based device previously deployed at the Idaho National Laboratory's TRansient REActor Test Facility (better known as TREAT) for monitoring fast neutrons emitted during pulsing of fissile fuel samples. Past use of these devices relied on pulse-shape discrimination to reduce the significant levels of background Cherenkov radiation. Proposed are two simple designs that reduce the overall light guide mass (here, polymethyl methacrylate or PMMA), employ silicon photomultipliers (SiPMs), and can be operated using pulse-height discrimination alone to eliminate background noise to acceptable levels. Geant4 was first used to model a traditional Hornyak button, and for assumed, hodoscope-like conditions, an intrinsic efficiency of 0.35% for mono-directional fission neutrons was predicted. The predicted efficiency is in reasonably good agreement with experimental data from the literature and, hence, served to validate the physics models and approximations employed. Geant4 models were then developed to optimize the materials and geometries of two alternatives to the Hornyak button, one based on a homogeneous mixture of ZnS(Ag) and PMMA, and one based on alternating layers of ZnS(Ag) and PMMA oriented perpendicular to the incident neutron beam. For the same radiation environment, optimized, 5-cm long (along the beam path) devices of the homogeneous and layered designs were predicted to have efficiencies of approximately 1.3% and 3.3%, respectively. For longer devices, i.e., lengths larger than 25 cm, these efficiencies were shown to peak at approximately 2.2% and 5.9%, respectively. Moreover, both designs were shown to discriminate Cherenkov noise intrinsically by using an appropriate pulse-height discriminator level, i.e., pulse-shape discrimination is not needed for these devices.

  18. Monte-Carlo Modelling and Verification of Photoluminescence of Gd{sub 2}O{sub 3}:Eu Scintillator by Using the GEANT4 Simulation Code

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Gyu-Seok; Kim, Kum-Bae; Choi, Sang-Hyoun [Korea Institute of Radiological and Medical Science, Seoul (Korea, Republic of); Song, Yong-Keun [Inje University, Gimhae (Korea, Republic of); Lee, Soon-Sung [University of Science and Technology, Daejeon (Korea, Republic of)

    2017-01-15

    Recently, Monte Carlo methods have been used to optimize the design and modeling of radiation detectors. However, most Monte Carlo codes have a fixed and simple optical physics, and the effect of the signal readout devices is not considered because of the limitations of the geometry function. Therefore, the disadvantages of the codes prevent the modeling of the scintillator detector. The modeling of a comprehensive and extensive detector system has been reported to be feasible when the optical physics model of the GEomerty ANd Tracking 4 (GEANT 4) simulation code is used. In this study, we performed a Gd{sub 2}O{sub 3}:Eu scintillator modelling by using the GEANT4 simulation code and compared the results with the measurement data. To obtain the measurement data for the scintillator, we synthesized the Gd{sub 2}O{sub 3}:Eu scintillator by using solution combustion method and we evaluated the characteristics of the scintillator by using X-ray diffraction and photoluminescence. We imported the measured data into the GEANT4 code because GEANT4 cannot simulate a fluorescence phenomenon. The imported data were used as an energy distribution for optical photon generation based on the energy deposited in the scintillator. As a result of the simulation, a strong emission peak consistent with the measured data was observed at 611 nm, and the overall trends of the spectrum agreed with the measured data. This result is significant because the characteristics of the scintillator are equally implemented in the simulation, indicating a valuable improvement in the modeling of scintillator-based radiation detectors.

  19. SU-E-T-427: Feasibility Study for Evaluation of IMRT Dose Distribution Using Geant4-Based Automated Algorithms

    International Nuclear Information System (INIS)

    Choi, H; Shin, W; Testa, M; Min, C; Kim, J

    2015-01-01

    Purpose: For intensity-modulated radiation therapy (IMRT) treatment planning validation using Monte Carlo (MC) simulations, a precise and automated procedure is necessary to evaluate the patient dose distribution. The aim of this study is to develop an automated algorithm for IMRT simulations using DICOM files and to evaluate the patient dose based on 4D simulation using the Geant4 MC toolkit. Methods: The head of a clinical linac (Varian Clinac 2300 IX) was modeled in Geant4 along with particular components such as the flattening filter and the multi-leaf collimator (MLC). Patient information and the position of the MLC were imported from the DICOM-RT interface. For each position of the MLC, a step- and-shoot technique was adopted. PDDs and lateral profiles were simulated in a water phantom (50×50×40 cm 3 ) and compared to measurement data. We used a lung phantom and MC-dose calculations were compared to the clinical treatment planning used at the Seoul National University Hospital. Results: In order to reproduce the measurement data, we tuned three free parameters: mean and standard deviation of the primary electron beam energy and the beam spot size. These parameters for 6 MV were found to be 5.6 MeV, 0.2378 MeV and 1 mm FWHM respectively. The average dose difference between measurements and simulations was less than 2% for PDDs and radial profiles. The lung phantom study showed fairly good agreement between MC and planning dose despite some unavoidable statistical fluctuation. Conclusion: The current feasibility study using the lung phantom shows the potential for IMRT dose validation using 4D MC simulations using Geant4 tool kits. This research was supported by Korea Institute of Nuclear safety and Development of Measurement Standards for Medical Radiation funded by Korea research Institute of Standards and Science. (KRISS-2015-15011032)

  20. Absorbing CAD system geometries into GEANT

    International Nuclear Information System (INIS)

    Womersley, J.; Dragovitsch, P.; Youssef, S.

    1991-01-01

    The simulation community has for many years discussed the possibility of direct conversion of geometrical detector models from computer- aided design and engineering systems (CAD systems) to the simulation packages (which we shall assume means GEANT). This would allow fast and simultaneous optimization of the physics performance and structural integrity of detector designs. The benefit that this would offer is the avoidance of such problems as the late discovery of the rather thick cryostats in the D-Zero detector. Recent progress in the absorption of CAD geometries into GEANT models is reviewed, including descriptions of the additions to the I-DEAS solid modeller package developed for the EMPACT SSC proposal, the COGENT CAD-to-GEANT interpreter developed by Quantum Research Services, and the OCTAGON package for representing arbitrary shapes in GEANT. Likely future directions of development are described. 2 refs., 7 figs

  1. Calculation of self–shielding factor for neutron activation experiments using GEANT4 and MCNP

    Energy Technology Data Exchange (ETDEWEB)

    Romero–Barrientos, Jaime, E-mail: jaromero@ing.uchile.cl [Comisión Chilena de Energía Nuclear, Nueva Bilbao 12501, Las Condes, Santiago (Chile); Universidad de Chile, DFI, Facultad de Ciencias Físicas Y Matemáticas, Avenida Blanco Encalada 2008, Santiago (Chile); Molina, F. [Comisión Chilena de Energía Nuclear, Nueva Bilbao 12501, Las Condes, Santiago (Chile); Aguilera, Pablo [Comisión Chilena de Energía Nuclear, Nueva Bilbao 12501, Las Condes, Santiago (Chile); Universidad de Chile, Depto. de Física, Facultad de Ciencias, Las Palmeras 3425, Ñuñoa, Santiago (Chile); Arellano, H. F. [Universidad de Chile, DFI, Facultad de Ciencias Físicas Y Matemáticas, Avenida Blanco Encalada 2008, Santiago (Chile)

    2016-07-07

    The neutron self–shielding factor G as a function of the neutron energy was obtained for 14 pure metallic samples in 1000 isolethargic energy bins from 1·10{sup −5}eV to 2·10{sup 7}eV using Monte Carlo simulations in GEANT4 and MCNP6. The comparison of these two Monte Carlo codes shows small differences in the final self–shielding factor mostly due to the different cross section databases that each program uses.

  2. The GEANT-CALOR interface

    International Nuclear Information System (INIS)

    Zeitnitz, C.; Gabriel, T.A.

    1994-01-01

    The simulation of large scale high energy physics experiments is based mainly on the GEANT package. In the current version 3.15 the simulation of hadronic interacting particles is based on GHEISHA or FLUKA. Both programs miss an accurate simulation of the interaction of low energy neutrons (E kin < 20 MeV) with the materials of the detector. The CALOR89 program package contains a low energetic neutron code. An interface between the CALOR program parts and the GEANT package has been developed

  3. Validation of a virtual source model of medical linac for Monte Carlo dose calculation using multi-threaded Geant4

    Science.gov (United States)

    Aboulbanine, Zakaria; El Khayati, Naïma

    2018-04-01

    The use of phase space in medical linear accelerator Monte Carlo (MC) simulations significantly improves the execution time and leads to results comparable to those obtained from full calculations. The classical representation of phase space stores directly the information of millions of particles, producing bulky files. This paper presents a virtual source model (VSM) based on a reconstruction algorithm, taking as input a compressed file of roughly 800 kb derived from phase space data freely available in the International Atomic Energy Agency (IAEA) database. This VSM includes two main components; primary and scattered particle sources, with a specific reconstruction method developed for each. Energy spectra and other relevant variables were extracted from IAEA phase space and stored in the input description data file for both sources. The VSM was validated for three photon beams: Elekta Precise 6 MV/10 MV and a Varian TrueBeam 6 MV. Extensive calculations in water and comparisons between dose distributions of the VSM and IAEA phase space were performed to estimate the VSM precision. The Geant4 MC toolkit in multi-threaded mode (Geant4-[mt]) was used for fast dose calculations and optimized memory use. Four field configurations were chosen for dose calculation validation to test field size and symmetry effects, , , and for squared fields, and for an asymmetric rectangular field. Good agreement in terms of formalism, for 3%/3 mm and 2%/3 mm criteria, for each evaluated radiation field and photon beam was obtained within a computation time of 60 h on a single WorkStation for a 3 mm voxel matrix. Analyzing the VSM’s precision in high dose gradient regions, using the distance to agreement concept (DTA), showed also satisfactory results. In all investigated cases, the mean DTA was less than 1 mm in build-up and penumbra regions. In regards to calculation efficiency, the event processing speed is six times faster using Geant4-[mt] compared to sequential

  4. Simulations of GCR interactions within planetary bodies using GEANT4

    Science.gov (United States)

    Mesick, K.; Feldman, W. C.; Stonehill, L. C.; Coupland, D. D. S.

    2017-12-01

    On planetary bodies with little to no atmosphere, Galactic Cosmic Rays (GCRs) can hit the body and produce neutrons primarily through nuclear spallation within the top few meters of the surfaces. These neutrons undergo further nuclear interactions with elements near the planetary surface and some will escape the surface and can be detected by landed or orbiting neutron radiation detector instruments. The neutron leakage signal at fast neutron energies provides a measure of average atomic mass of the near-surface material and in the epithermal and thermal energy ranges is highly sensitive to the presence of hydrogen. Gamma-rays can also escape the surface, produced at characteristic energies depending on surface composition, and can be detected by gamma-ray instruments. The intra-nuclear cascade (INC) that occurs when high-energy GCRs interact with elements within a planetary surface to produce the leakage neutron and gamma-ray signals is highly complex, and therefore Monte Carlo based radiation transport simulations are commonly used for predicting and interpreting measurements from planetary neutron and gamma-ray spectroscopy instruments. In the past, the simulation code that has been widely used for this type of analysis is MCNPX [1], which was benchmarked against data from the Lunar Neutron Probe Experiment (LPNE) on Apollo 17 [2]. In this work, we consider the validity of the radiation transport code GEANT4 [3], another widely used but open-source code, by benchmarking simulated predictions of the LPNE experiment to the Apollo 17 data. We consider the impact of different physics model options on the results, and show which models best describe the INC based on agreement with the Apollo 17 data. The success of this validation then gives us confidence in using GEANT4 to simulate GCR-induced neutron leakage signals on Mars in relevance to a re-analysis of Mars Odyssey Neutron Spectrometer data. References [1] D.B. Pelowitz, Los Alamos National Laboratory, LA-CP-05

  5. INFLUENCIA DE LA PRESIÓN ATMOSFÉRICA EN LAS TRANSMISIONES A FRECUENCIA 2.4 GHz

    OpenAIRE

    González Romero, Pedro Vicente; Espina Ávila, Luis Gerardo

    2012-01-01

    La presente investigación se planteó como propósito fundamental determinar la influencia de la presión atmosférica sobre una señal transmitida en una frecuencia de 2.4 GHz. La investigación es de tipo explicativa, con diseño metodológico experimental. Mediante ella se obtiene la atenuación de una señal de 2.4GHz a diferentes presiones atmosféricas y se determinan las gráficas que muestran el comportamiento observado. Como resultado de esta investigación se observó que sí existe una influencia...

  6. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

    Science.gov (United States)

    Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

    2015-07-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10-6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications.

  7. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

    International Nuclear Information System (INIS)

    Lemaréchal, Yannick; Bert, Julien; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris; Falconnet, Claire; Després, Philippe; Valeri, Antoine

    2015-01-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125 I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10 −6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications. (paper)

  8. A Geant4 simulation of the depth dose percentage in brain tumors treatments using protons and carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, José A. M., E-mail: joadiazme@unal.edu.co; Torres, D. A., E-mail: datorresg@unal.edu.co [Physics Department, Universidad Nacional de Colombia, Bogot (Colombia)

    2016-07-07

    The deposited energy and dose distribution of beams of protons and carbon over a head are simulated using the free tool package Geant4 and the data analysis package ROOT-C++. The present work shows a methodology to understand the microscopical process occurring in a session of hadron-therapy using advance simulation tools.

  9. The generation of absorbed dose profiles of proton beam in water using Geant4 code

    International Nuclear Information System (INIS)

    Christovao, Marilia T.; Campos, Tarcisio Passos R. de

    2007-01-01

    The present article approaches simulations on the proton beam radiation therapy, using an application based on the code GEANT4, with Open GL as a visualization drive and JAS3 (Java Analysis Studio) analysis data tools systems, implementing the AIDA interfaces. The proton radiotherapy is adapted to treat cancer or other benign tumors that are close to sensitive structures, since it allows precise irradiation of the target with high doses, while the health tissues adjacent to vital organs and tissues are preserved, due to physical property of dose profile. GEANT4 is a toolkit for simulating the transport of particles through matter, in complex geometries. Taking advantage of the object-oriented project features, the user can adapt or extend the tool in all domain, due to the flexibility of the code, providing a subroutine's group for materials definition, geometries and particles properties in agreement with the user's needs to generate the Monte Carlo simulation. In this paper, the parameters of beam line used in the simulation possess adjustment elements, such as: the range shifter, composition and dimension; the beam line, energy, intensity, length, according with physic processes applied. The simulation result is the depth dose profiles on water, dependent on the various incident beam energy. Starting from those profiles, one can define appropriate conditions for proton radiotherapy in ocular region. (author)

  10. Analysis of GEANT4 Physics List Properties in the 12 GeV MOLLER Simulation Framework

    Science.gov (United States)

    Haufe, Christopher; Moller Collaboration

    2013-10-01

    To determine the validity of new physics beyond the scope of the electroweak theory, nuclear physicists across the globe have been collaborating on future endeavors that will provide the precision needed to confirm these speculations. One of these is the MOLLER experiment - a low-energy particle experiment that will utilize the 12 GeV upgrade of Jefferson Lab's CEBAF accelerator. The motivation of this experiment is to measure the parity-violating asymmetry of scattered polarized electrons off unpolarized electrons in a liquid hydrogen target. This measurement would allow for a more precise determination of the electron's weak charge and weak mixing angle. While still in its planning stages, the MOLLER experiment requires a detailed simulation framework in order to determine how the project should be run in the future. The simulation framework for MOLLER, called ``remoll'', is written in GEANT4 code. As a result, the simulation can utilize a number of GEANT4 coded physics lists that provide the simulation with a number of particle interaction constraints based off of different particle physics models. By comparing these lists with one another using the data-analysis application ROOT, the most optimal physics list for the MOLLER simulation can be determined and implemented. This material is based upon work supported by the National Science Foundation under Grant No. 714001.

  11. Validation of nuclear models in Geant4 using the dose distribution of a 177 MeV proton pencil beam

    International Nuclear Information System (INIS)

    Hall, David C; Paganetti, Harald; Makarova, Anastasia; Gottschalk, Bernard

    2016-01-01

    A proton pencil beam is associated with a surrounding low-dose envelope, originating from nuclear interactions. It is important for treatment planning systems to accurately model this envelope when performing dose calculations for pencil beam scanning treatments, and Monte Carlo (MC) codes are commonly used for this purpose. This work aims to validate the nuclear models employed by the Geant4 MC code, by comparing the simulated absolute dose distribution to a recent experiment of a 177 MeV proton pencil beam stopping in water. Striking agreement is observed over five orders of magnitude, with both the shape and normalisation well modelled. The normalisations of two depth dose curves are lower than experiment, though this could be explained by an experimental positioning error. The Geant4 neutron production model is also verified in the distal region. The entrance dose is poorly modelled, suggesting an unaccounted upstream source of low-energy protons. Recommendations are given for a follow-up experiment which could resolve these issues. (note)

  12. Geant4 simulations of the absorption of photons in CsI and NaI produced by electrons with energies up to 4 MeV and their application to precision measurements of the β-energy spectrum with a calorimetric technique

    Science.gov (United States)

    Huyan, X.; Naviliat-Cuncic, O.; Voytas, P.; Chandavar, S.; Hughes, M.; Minamisono, K.; Paulauskas, S. V.

    2018-01-01

    The yield of photons produced by electrons slowing down in CsI and NaI was studied with four electromagnetic physics constructors included in the Geant4 toolkit. The subsequent absorption of photons in detector geometries used for measurements of the β spectrum shape was also studied with a focus on the determination of the absorption fraction. For electrons with energies in the range 0.5-4 MeV, the relative photon yields determined with the four Geant4 constructors differ at the level of 10-2 in amplitude and the relative absorption fractions differ at the level of 10-4 in amplitude. The differences among constructors enabled the estimation of the sensitivity to Geant4 simulations for the measurement of the β energy spectrum shape in 6He decay using a calorimetric technique with ions implanted in the active volume of detectors. The size of the effect associated with photons escaping the detectors was quantified in terms of a slope which, on average, is respectively - 5 . 4 %/MeV and - 4 . 8 %/MeV for the CsI and NaI geometries. The corresponding relative uncertainties as determined from the spread of results obtained with the four Geant4 constructors are 0.0067 and 0.0058.

  13. GeantV: from CPU to accelerators

    Science.gov (United States)

    Amadio, G.; Ananya, A.; Apostolakis, J.; Arora, A.; Bandieramonte, M.; Bhattacharyya, A.; Bianchini, C.; Brun, R.; Canal, P.; Carminati, F.; Duhem, L.; Elvira, D.; Gheata, A.; Gheata, M.; Goulas, I.; Iope, R.; Jun, S.; Lima, G.; Mohanty, A.; Nikitina, T.; Novak, M.; Pokorski, W.; Ribon, A.; Sehgal, R.; Shadura, O.; Vallecorsa, S.; Wenzel, S.; Zhang, Y.

    2016-10-01

    The GeantV project aims to research and develop the next-generation simulation software describing the passage of particles through matter. While the modern CPU architectures are being targeted first, resources such as GPGPU, Intel© Xeon Phi, Atom or ARM cannot be ignored anymore by HEP CPU-bound applications. The proof of concept GeantV prototype has been mainly engineered for CPU's having vector units but we have foreseen from early stages a bridge to arbitrary accelerators. A software layer consisting of architecture/technology specific backends supports currently this concept. This approach allows to abstract out the basic types such as scalar/vector but also to formalize generic computation kernels using transparently library or device specific constructs based on Vc, CUDA, Cilk+ or Intel intrinsics. While the main goal of this approach is portable performance, as a bonus, it comes with the insulation of the core application and algorithms from the technology layer. This allows our application to be long term maintainable and versatile to changes at the backend side. The paper presents the first results of basket-based GeantV geometry navigation on the Intel© Xeon Phi KNC architecture. We present the scalability and vectorization study, conducted using Intel performance tools, as well as our preliminary conclusions on the use of accelerators for GeantV transport. We also describe the current work and preliminary results for using the GeantV transport kernel on GPUs.

  14. GeantV: from CPU to accelerators

    International Nuclear Information System (INIS)

    Amadio, G; Bianchini, C; Iope, R; Ananya, A; Arora, A; Apostolakis, J; Bandieramonte, M; Brun, R; Carminati, F; Gheata, A; Gheata, M; Goulas, I; Nikitina, T; Bhattacharyya, A; Mohanty, A; Canal, P; Elvira, D; Jun, S; Lima, G; Duhem, L

    2016-01-01

    The GeantV project aims to research and develop the next-generation simulation software describing the passage of particles through matter. While the modern CPU architectures are being targeted first, resources such as GPGPU, Intel© Xeon Phi, Atom or ARM cannot be ignored anymore by HEP CPU-bound applications. The proof of concept GeantV prototype has been mainly engineered for CPU's having vector units but we have foreseen from early stages a bridge to arbitrary accelerators. A software layer consisting of architecture/technology specific backends supports currently this concept. This approach allows to abstract out the basic types such as scalar/vector but also to formalize generic computation kernels using transparently library or device specific constructs based on Vc, CUDA, Cilk+ or Intel intrinsics. While the main goal of this approach is portable performance, as a bonus, it comes with the insulation of the core application and algorithms from the technology layer. This allows our application to be long term maintainable and versatile to changes at the backend side. The paper presents the first results of basket-based GeantV geometry navigation on the Intel© Xeon Phi KNC architecture. We present the scalability and vectorization study, conducted using Intel performance tools, as well as our preliminary conclusions on the use of accelerators for GeantV transport. We also describe the current work and preliminary results for using the GeantV transport kernel on GPUs. (paper)

  15. Monte Carlo simulation in nuclear medicine, radiotherapy-brachytherapy with a simulation platform GATE based on Geant4

    International Nuclear Information System (INIS)

    Berger, L.; Breton, V.; Donnarieix, D.; Elbitar, Z.; Gisclon, D.; Lazaro, D.; Maigne, L.; Reuillon, R.; Thiam, C.O.; Donnarieix, D.

    2003-01-01

    The totality of simulations made with the G.A.T.E. software gives extremely conclusive results. Its easiness to use and the power of the G.E.A.N.T.4. simulation code make of it a performing tool. The works made to parallel the simulation code reduce considerably the calculation time for a given simulation. A public version is planned for may 2004. (N.C.)

  16. A Geant4 simulation package for the TASISpec experimental detector setup

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento, L.G., E-mail: lgsarmientop@unal.edu.co [Universidad Nacional de Colombia, Bogota D.C. 111321 (Colombia); Lund University, S-22100 Lund (Sweden); Andersson, L.-L. [University of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE (United Kingdom); Rudolph, D. [Lund University, S-22100 Lund (Sweden)

    2012-03-01

    The experimental detector setup TASISpec (TA SCA in Small Image mode Spectroscopy) comprises composite Ge- and highly segmented Si-detectors. The setup is constructed to provide multi-coincidence spectroscopic data between {gamma}-rays, X-rays, conversion electrons, fission fragments, and {alpha}-particles for heavy and superheavy elements (Z{>=}100). The full array has been virtually constructed using the Geant4 simulation toolkit. The simulations will not only be used to explore the possibilities of the detector setup itself. More important, however, they will also shed light on the nuclear structure of the heaviest elements. This can be done by comparing the simulated detector response of complex decay modes with the experimental data. Such an iterative or 'self-consistent' way to understand experimental observables will provide more reliability when disentangling the data and deducing experimental decay schemes.

  17. Geant4 calculations for space radiation shielding material Al2O3

    Science.gov (United States)

    Capali, Veli; Acar Yesil, Tolga; Kaya, Gokhan; Kaplan, Abdullah; Yavuz, Mustafa; Tilki, Tahir

    2015-07-01

    Aluminium Oxide, Al2O3 is the most widely used material in the engineering applications. It is significant aluminium metal, because of its hardness and as a refractory material owing to its high melting point. This material has several engineering applications in diverse fields such as, ballistic armour systems, wear components, electrical and electronic substrates, automotive parts, components for electric industry and aero-engine. As well, it is used as a dosimeter for radiation protection and therapy applications for its optically stimulated luminescence properties. In this study, stopping powers and penetrating distances have been calculated for the alpha, proton, electron and gamma particles in space radiation shielding material Al2O3 for incident energies 1 keV - 1 GeV using GEANT4 calculation code.

  18. Simulation and modeling for the stand-off radiation detection system (SORDS) using GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, Andrew S [Los Alamos National Laboratory; Wallace, Mark [Los Alamos National Laboratory; Galassi, Mark [Los Alamos National Laboratory; Mocko, Michal [Los Alamos National Laboratory; Palmer, David [Los Alamos National Laboratory; Schultz, Larry [Los Alamos National Laboratory; Tornga, Shawn [Los Alamos National Laboratory

    2009-01-01

    A Stand-Off Radiation Detection System (SORDS) is being developed through a joint effort by Raytheon, Los Alamos National Laboratory, Bubble Technology Industries, Radiation Monitoring Devices, and the Massachusetts Institute of Technology, for the Domestic Nuclear Detection Office (DNDO). The system is a mobile truck-based platform performing detection, imaging, and spectroscopic identification of gamma-ray sources. A Tri-Modal Imaging (TMI) approach combines active-mask coded aperture imaging, Compton imaging, and shadow imaging techniques. Monte Carlo simulation and modeling using the GEANT4 toolkit was used to generate realistic data for the development of imaging algorithms and associated software code.

  19. Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry.

    Science.gov (United States)

    Chagren, S; Tekaya, M Ben; Reguigui, N; Gharbi, F

    2016-01-01

    In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a "virtual" reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60-2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Monte Carlo Simulation of Electron Beams for Radiotherapy - EGS4, MCNP4b and GEANT3 Intercomparison

    CERN Document Server

    Trindade, A; Alves, C M; Chaves, A; Lopes, C; Oliveira, C; Peralta, L

    2000-01-01

    In medical radiation physics, an increasing number of Monte Carlo codes are being used, which requires intercomparison between them to evaluated the accuracy of the simulated results against benchmark experiments. The Monte Carlo code EGS4, commonly used to simulate electron beams from medical linear accelerators, was compared with GEANT3 and MCNP4b. Intercomparison of electron energy spectra, angular and spatial distribution were carried out for the Siemens KD2 linear accelerator, at beam energies of 10 and 15 MeV for a field size of 10x10 cm2. Indirect validation was performed against electron depth doses curves and beam profiles measured in a MP3-PTW water phantom using a Markus planar chamber. Monte Carlo isodose lines were reconstructed and compared to those from commercial treatment planning systems (TPS's) and with experimental data.

  1. The GeantV project: preparing the future of simulation

    International Nuclear Information System (INIS)

    Amadio, G; Bianchini, C; Iope, R L; Apostolakis, J; Brun, R; Carminati, F; Gheata, A; Nikitina, T; Novak, M; Pokorski, W; Shadura, O; Bandieramonte, M; Bhattacharyya, A; Mohanty, A; Seghal, R; Canal, Ph; Elvira, D; Lima, G; Duhem, L; De Fine Licht, J

    2015-01-01

    Detector simulation is consuming at least half of the HEP computing cycles, and even so, experiments have to take hard decisions on what to simulate, as their needs greatly surpass the availability of computing resources. New experiments still in the design phase such as FCC, CLIC and ILC as well as upgraded versions of the existing LHC detectors will push further the simulation requirements. Since the increase in computing resources is not likely to keep pace with our needs, it is therefore necessary to explore innovative ways of speeding up simulation in order to sustain the progress of High Energy Physics. The GeantV project aims at developing a high performance detector simulation system integrating fast and full simulation that can be ported on different computing architectures, including CPU accelerators. After more than two years of R and D the project has produced a prototype capable of transporting particles in complex geometries exploiting micro-parallelism, SIMD and multithreading. Portability is obtained via C++ template techniques that allow the development of machine- independent computational kernels. A set of tables derived from Geant4 for cross sections and final states provides a realistic shower development and, having been ported into a Geant4 physics list, can be used as a basis for a direct performance comparison. (paper)

  2. Designing a new type of neutron detector for neutron and gamma-ray discrimination via GEANT4

    International Nuclear Information System (INIS)

    Shan, Qing; Chu, Shengnan; Ling, Yongsheng; Cai, Pingkun; Jia, Wenbao

    2016-01-01

    Design of a new type of neutron detector, consisting of a fast neutron converter, plastic scintillator, and Cherenkov detector, to discriminate 14-MeV fast neutrons and gamma rays in a pulsed n–γ mixed field and monitor their neutron fluxes is reported in this study. Both neutrons and gamma rays can produce fluorescence in the scintillator when they are incident on the detector. However, only the secondary charged particles of the gamma rays can produce Cherenkov light in the Cherenkov detector. The neutron and gamma-ray fluxes can be calculated by measuring the fluorescence and Cherenkov light. The GEANT4 Monte Carlo simulation toolkit is used to simulate the whole process occurring in the detector, whose optimum parameters are known. Analysis of the simulation results leads to a calculation method of neutron flux. This method is verified by calculating the neutron fluxes using pulsed n–γ mixed fields with different n/γ ratios, and the results show that the relative errors of all calculations are <5%. - Highlights: • A neutron detector is developed to discriminate 14-MeV fast neutrons and gamma rays. • The GEANT4 is used to optimize the parameters of the detector. • A calculation method of neutron flux is established through the simulation. • Several n/γ mixture fields are simulated to validate of the calculation method.

  3. Geant4 electromagnetic physics for high statistic simulation of LHC experiments

    CERN Document Server

    Allison, J; Bagulya, A; Champion, C; Elles, S; Garay, F; Grichine, V; Howard, A; Incerti, S; Ivanchenko, V; Jacquemier, J; Maire, M; Mantero, A; Nieminen, P; Pandola, L; Santin, G; Sawkey, D; Schalicke, A; Urban, L

    2012-01-01

    An overview of the current status of electromagnetic physics (EM) of the Geant4 toolkit is presented. Recent improvements are focused on the performance of large scale production for LHC and on the precision of simulation results over a wide energy range. Significant efforts have been made to improve the accuracy without compromising of CPU speed for EM particle transport. New biasing options have been introduced, which are applicable to any EM process. These include algorithms to enhance and suppress processes, force interactions or splitting of secondary particles. It is shown that the performance of the EM sub-package is improved. We will report extensions of the testing suite allowing high statistics validation of EM physics. It includes validation of multiple scattering, bremsstrahlung and other models. Cross checks between standard and low-energy EM models have been performed using evaluated data libraries and reference benchmark results.

  4. Geant4 calculations for space radiation shielding material Al2O3

    Directory of Open Access Journals (Sweden)

    Capali Veli

    2015-01-01

    Full Text Available Aluminium Oxide, Al2O3 is the most widely used material in the engineering applications. It is significant aluminium metal, because of its hardness and as a refractory material owing to its high melting point. This material has several engineering applications in diverse fields such as, ballistic armour systems, wear components, electrical and electronic substrates, automotive parts, components for electric industry and aero-engine. As well, it is used as a dosimeter for radiation protection and therapy applications for its optically stimulated luminescence properties. In this study, stopping powers and penetrating distances have been calculated for the alpha, proton, electron and gamma particles in space radiation shielding material Al2O3 for incident energies 1 keV – 1 GeV using GEANT4 calculation code.

  5. Simulation and Digitization of a Gas Electron Multiplier Detector Using Geant4 and an Object-Oriented Digitization Program

    Science.gov (United States)

    McMullen, Timothy; Liyanage, Nilanga; Xiong, Weizhi; Zhao, Zhiwen

    2017-01-01

    Our research has focused on simulating the response of a Gas Electron Multiplier (GEM) detector using computational methods. GEM detectors provide a cost effective solution for radiation detection in high rate environments. A detailed simulation of GEM detector response to radiation is essential for the successful adaption of these detectors to different applications. Using Geant4 Monte Carlo (GEMC), a wrapper around Geant4 which has been successfully used to simulate the Solenoidal Large Intensity Device (SoLID) at Jefferson Lab, we are developing a simulation of a GEM chamber similar to the detectors currently used in our lab. We are also refining an object-oriented digitization program, which translates energy deposition information from GEMC into electronic readout which resembles the readout from our physical detectors. We have run the simulation with beta particles produced by the simulated decay of a 90Sr source, as well as with a simulated bremsstrahlung spectrum. Comparing the simulation data with real GEM data taken under similar conditions is used to refine the simulation parameters. Comparisons between results from the simulations and results from detector tests will be presented.

  6. Muon Telescope (MuTe): A first study using Geant4

    Science.gov (United States)

    Asorey, H.; Balaguera-Rojas, A.; Calderon-Ardila, R.; Núñez, L. A.; Sanabria-Gómez, J. D.; Súarez-Durán, M.; Tapia, A.

    2017-07-01

    Muon tomography is based on recording the difference of absorption of muons by matter, as ordinary radiography does for using X-rays. The interaction of cosmic rays with the atmosphere produces extensive air showers which provides an abundant source for atmospheric muons, benefiting various applications of muon tomography, particularly the study of the inner structure of volcanoes. The MuTe (for Muon Telescope) is a hybrid detector composed of scintillation bars and a water Cherenkov detector designed to measure cosmic muon flux crossing volcanic edifices. This detector consists of two scintillator plates (1.44 m2 with 30 x 30 pixels), with a maximum distance of 2.0m of separation. In this work we report the first simulation of the MuTe using GEANT4 -set of simulation tools, based in C++ - that provides information about the interaction between radiation and matter. This computational tool allows us to know the energy deposited by the muons and modeling the response of the scintillators and the water cherenkov detector to the passage of radiation which is crucial to compare to our data analysis.

  7. Dose calculations at high altitudes and in deep space with GEANT4 using BIC and JQMD models for nucleus-nucleus reactions

    International Nuclear Information System (INIS)

    Sihver, L; Mancusi, D; Matthiae, D; Koi, T

    2008-01-01

    Radiation exposure of aircrew is more and more recognized as an occupational hazard. The ionizing environment at standard commercial aircraft flight altitudes consists mainly of secondary particles, of which the neutrons give a major contribution to the dose equivalent. Accurate estimations of neutron spectra in the atmosphere are therefore essential for correct calculations of aircrew doses. Energetic solar particle events (SPE) could also lead to significantly increased dose rates, especially at routes close to the North Pole, e.g. for flights between Europe and USA. It is also well known that the radiation environment encountered by personnel aboard low Earth orbit (LEO) spacecraft or aboard a spacecraft traveling outside the Earth's protective magnetosphere is much harsher compared with that within the atmosphere since the personnel are exposed to radiation from both galactic cosmic rays (GCR) and SPE. The relative contribution to the dose from GCR when traveling outside the Earth's magnetosphere, e.g. to the Moon or Mars, is even greater, and reliable and accurate particle and heavy ion transport codes are essential to calculate the radiation risks for both aircrew and personnel on spacecraft. We have therefore performed calculations of neutron distributions in the atmosphere, total dose equivalents, and quality factors at different depths in a water sphere in an imaginary spacecraft during solar minimum in a geosynchronous orbit. The calculations were performed with the GEANT4 Monte Carlo (MC) code using both the binary cascade (BIC) model, which is part of the standard GEANT4 package, and the JQMD model, which is used in the particle and heavy ion transport code PHITS GEANT4.

  8. Dose calculations at high altitudes and in deep space with GEANT4 using BIC and JQMD models for nucleus nucleus reactions

    Science.gov (United States)

    Sihver, L.; Matthiä, D.; Koi, T.; Mancusi, D.

    2008-10-01

    Radiation exposure of aircrew is more and more recognized as an occupational hazard. The ionizing environment at standard commercial aircraft flight altitudes consists mainly of secondary particles, of which the neutrons give a major contribution to the dose equivalent. Accurate estimations of neutron spectra in the atmosphere are therefore essential for correct calculations of aircrew doses. Energetic solar particle events (SPE) could also lead to significantly increased dose rates, especially at routes close to the North Pole, e.g. for flights between Europe and USA. It is also well known that the radiation environment encountered by personnel aboard low Earth orbit (LEO) spacecraft or aboard a spacecraft traveling outside the Earth's protective magnetosphere is much harsher compared with that within the atmosphere since the personnel are exposed to radiation from both galactic cosmic rays (GCR) and SPE. The relative contribution to the dose from GCR when traveling outside the Earth's magnetosphere, e.g. to the Moon or Mars, is even greater, and reliable and accurate particle and heavy ion transport codes are essential to calculate the radiation risks for both aircrew and personnel on spacecraft. We have therefore performed calculations of neutron distributions in the atmosphere, total dose equivalents, and quality factors at different depths in a water sphere in an imaginary spacecraft during solar minimum in a geosynchronous orbit. The calculations were performed with the GEANT4 Monte Carlo (MC) code using both the binary cascade (BIC) model, which is part of the standard GEANT4 package, and the JQMD model, which is used in the particle and heavy ion transport code PHITS GEANT4.

  9. GEANT4 simulation study of a gamma-ray detector for neutron resonance densitometry

    International Nuclear Information System (INIS)

    Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki

    2013-01-01

    A design study of a gamma-ray detector for neutron resonance densitometry was made with GEANT4. The neutron resonance densitometry, combining neutron resonance transmission analysis and neutron resonance capture analysis, is a non-destructive technique to measure amounts of nuclear materials in melted fuels of the Fukushima Daiichi nuclear power plants. In order to effectively quantify impurities in the melted fuels via prompt gamma-ray measurements, a gamma-ray detector for the neutron resonance densitometry consists of cylindrical and well type LaBr 3 scintillators. The present simulation showed that the proposed gamma-ray detector suffices to clearly detect the gamma rays emitted by 10 B(n, αγ) reaction in a high environmental background due to 137 Cs radioactivity with its Compton edge suppressed at a considerably small level. (author)

  10. Dose calculation on voxels phantoms using the GEANT4 code

    International Nuclear Information System (INIS)

    Martins, Maximiano C.; Santos, Denison S.; Queiroz Filho, Pedro P.; Begalli, Marcia

    2009-01-01

    This work implemented an anthropomorphic phantom of voxels on the structure of Monte Carlo GEANT4, for utilization by professionals from the radioprotection, external dosimetry and medical physics. This phantom allows the source displacement that can be isotropic punctual, plain beam, linear or radioactive gas, in order to obtain diverse irradiation geometries. In them, the radioactive sources exposure is simulated viewing the determination of effective dose or the dose in each organ of the human body. The Zubal head and body trunk phantom was used, and we can differentiate the organs and tissues by the chemical constitution in soft tissue, lung tissue, bone tissue, water and air. The calculation method was validated through the comparison with other well established method, the Visual Monte Carlo (VMC). Besides, a comparison was done with the international recommendation for the evaluation of dose by exposure to punctual sources, described in the document TECDOC - 1162- Generic Procedures for Assessment and Response During a Radiological Emergency, where analytical expressions for this calculation are given. Considerations are made on the validity limits of these expressions for various irradiation geometries, including linear sources, immersion into clouds and contaminated soils

  11. Towards the development of a comprehensive model of an electronic portal imaging device using Geant4

    International Nuclear Information System (INIS)

    Blake, S.; Kuncic, Z.; Vial, P.; Holloway, L.

    2010-01-01

    Full text: This work represents the first stage of an ongoing study to investigate the physical processes occurring within electronic portal imaging devices (EPlDs), including the effects of optical scattering on image quality and dosimetry. The objective of this work was to develop an initial Monte Carlo model of a linear accelerator (Iinac) beam and an EPID. The ability to simulate the radiation transport of both high energy and optical photons in a single Monte Carlo model was tested. Data from the Phase-space database for external beam radiotherapy (International Atomic Energy Agency, IAEA) was used with the Geant4 toolkit to construct a model of a Siemens Primus linac 6 MY photon source. Dose profiles and percent depth dose (PDD) curves were extracted from simulations of dose in water and compared to experimental measurements. A preliminary EPID model was developed to incorporate both high energy radiation and optical photon transport. Agreement in dose profiles inside the open beam was within 1.6%. Mean agreement in PDD curves beyond depth of dose maximum was within 6.1 % (local percent difference). The radiation transport of both high energy and optical photons were simulated and visualized in the EPID model. Further work is required to experimentally validate the EPID model. The comparison of simulated dose in water with measurements indicates that the IAEA phase-space may represent an accurate model of a linac source. We have demonstrated the feasibility of developing a comprehensive EPID model incorporating both high energy and optical physics in Geant4. (author)

  12. Implementation of a model in Geant4 of an accelerator on Cloudmc, a Web application for the parallelization of Monte Carlo simulations in the Cloud; Implementacion de un modelo en Geant4 de un acelerador en Cloudmc, una aplicacion Web para la paralelizacion de simulaciones Monte Carlo en la nube

    Energy Technology Data Exchange (ETDEWEB)

    Miras del Rio, H.; Jimenez Marrufo, R.; Cortes Giraldo, M. A.; Miras del Rio, C.

    2013-07-01

    This paper describes the implementation in CloudMC of a simulation program MC, based on the code of Geant4, a Siemens Accelerator model Oncor with the intention that in future can be used for calculation of radiation treatments with MC in short periods of time. (Author)

  13. ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy.

    Science.gov (United States)

    Afsharpour, H; Landry, G; D'Amours, M; Enger, S; Reniers, B; Poon, E; Carrier, J-F; Verhaegen, F; Beaulieu, L

    2012-06-07

    Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy.

  14. Simulations of neutron transport at low energy: a comparison between GEANT and MCNP.

    Science.gov (United States)

    Colonna, N; Altieri, S

    2002-06-01

    The use of the simulation tool GEANT for neutron transport at energies below 20 MeV is discussed, in particular with regard to shielding and dose calculations. The reliability of the GEANT/MICAP package for neutron transport in a wide energy range has been verified by comparing the results of simulations performed with this package in a wide energy range with the prediction of MCNP-4B, a code commonly used for neutron transport at low energy. A reasonable agreement between the results of the two codes is found for the neutron flux through a slab of material (iron and ordinary concrete), as well as for the dose released in soft tissue by neutrons. These results justify the use of the GEANT/MICAP code for neutron transport in a wide range of applications, including health physics problems.

  15. Development of a Geant4 application to characterise a prototype neutron detector based on three orthogonal 3He tubes inside an HDPE sphere.

    Science.gov (United States)

    Gracanin, V; Guatelli, S; Prokopovich, D; Rosenfeld, A B; Berry, A

    2017-01-01

    The Bonner Sphere Spectrometer (BSS) system is a well-established technique for neutron dosimetry that involves detection of thermal neutrons within a range of hydrogenous moderators. BSS detectors are often used to perform neutron field surveys in order to determine the ambient dose equivalent H*(10) and estimate health risk to personnel. There is a potential limitation of existing neutron survey techniques, since some detectors do not consider the direction of the neutron field, which can result in overly conservative estimates of dose in neutron fields. This paper shows the development of a Geant4 simulation application to characterise a prototype neutron detector based on three orthogonal 3 He tubes inside a single HDPE sphere built at the Australian Nuclear Science and Technology Organisation (ANSTO). The Geant4 simulation has been validated with respect to experimental measurements performed with an Am-Be source. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  16. Monte Carlo simulation of dose calculation in voxel and geometric phantoms using GEANT4 code

    International Nuclear Information System (INIS)

    Martins, Maximiano C.; Santos, Denison de S.; Queiroz Filho, Pedro P. de; Silva, Rosana de S. e; Begalli, Marcia

    2009-01-01

    Monte Carlo simulation techniques have become a valuable tool for scientific purposes. In radiation protection many quantities are obtained by means of the simulation of particles passing through human body models, also known as phantoms, allowing the calculation of doses deposited in an individual's organs exposed to ionizing radiation. These information are very useful from the medical viewpoint, as they are used in the planning of external beam radiotherapy and brachytherapy treatments. The goal of this work is the implementation of a voxel phantom and a geometrical phantom in the framework of the Geant4 tool kit, aiming at a future use of this code by professionals in the medical area. (author)

  17. Influencia de la responsabilidad social en la lealtad: aplicación en el mercado de servicios

    OpenAIRE

    García de los Salmones Sánchez, María del Mar; Rodríguez del Bosque Rodríguez, Ignacio Alfredo

    2011-01-01

    El presente trabajo analiza la influencia de la responsabilidad social corporativa en el comportamiento del consumidor mediante su inclusión en los modelos tradicionales de lealtad. Para ello, se parte de una revisión de la literatura sobre el concepto que da pie al planteamiento de varias hipótesis de investigación relativas a la influencia del comportamiento socialmente responsable en la valoración de un servicio y en la imagen corporativa, antecedentes directos, junto con...

  18. Abstract ID: 176 Geant4 implementation of inter-atomic interference effect in small-angle coherent X-ray scattering for materials of medical interest.

    Science.gov (United States)

    Paternò, Gianfranco; Cardarelli, Paolo; Contillo, Adriano; Gambaccini, Mauro; Taibi, Angelo

    2018-01-01

    Advanced applications of digital mammography such as dual-energy and tomosynthesis require multiple exposures and thus deliver higher dose compared to standard mammograms. A straightforward manner to reduce patient dose without affecting image quality would be removal of the anti-scatter grid, provided that the involved reconstruction algorithms are able to take the scatter figure into account [1]. Monte Carlo simulations are very well suited for the calculation of X-ray scatter distribution and can be used to integrate such information within the reconstruction software. Geant4 is an open source C++ particle tracking code widely used in several physical fields, including medical physics [2,3]. However, the coherent scattering cross section used by the standard Geant4 code does not take into account the influence of molecular interference. According to the independent atomic scattering approximation (the so-called free-atom model), coherent radiation is indistinguishable from primary radiation because its angular distribution is peaked in the forward direction. Since interference effects occur between x-rays scattered by neighbouring atoms in matter, it was shown experimentally that the scatter distribution is affected by the molecular structure of the target, even in amorphous materials. The most important consequence is that the coherent scatter distribution is not peaked in the forward direction, and the position of the maximum is strongly material-dependent [4]. In this contribution, we present the implementation of a method to take into account inter-atomic interference in small-angle coherent scattering in Geant4, including a dedicated data set of suitable molecular form factor values for several materials of clinical interest. Furthermore, we present scatter images of simple geometric phantoms in which the Rayleigh contribution is rigorously evaluated. Copyright © 2017.

  19. A Preliminary Study on Time Projection Chamber Simulation for Fission Cross Section Measurements with Geant4

    International Nuclear Information System (INIS)

    Kim, Jong Woon; Lee, Youngouk; Kim, Jae Cheon

    2014-01-01

    We present the details of the TPC simulation with Geant4 and show the results. TPC can provide more information than a fission chamber in that it is possible to distinguish different particle types. Simulations are conducted for uranium and plutonium targets with 20MeV neutrons. The simulation results are compared with the reference and show reasonable results. This is the first phase of study for realizing a TPC in the NFS at RAON, and we have more work to do, such as applying an electric field, signal processing in the simulation, and manufacturing of a TPC. The standard in fission cross section measurement is a fission chamber. It is basically just two parallel plates separated by a few centimeters of gas. A power supply connected to the plates sets up a moderate electric field. The target is deposited onto one of the plates. When fission occurs, the fragments ionize the gas, and the electric field causes the produced electrons to drift to the opposite plate, which records the total energy deposited in the chamber. A Time Projection Chamber (TPC) is a gas ionization detector similar to a fission chamber. However, it can measure the charged particle trajectories in the active volume in three dimensions by adding several readouts on the pad plane (fission chamber has only one readout one a pad plane). The specific ionization for each particle track enables the TPC to distinguish different particle types. A TPC will be used for fission cross section measurements in the Neutron Science Facility (NSF) at RAON. As a preliminary study, we present details of TPC simulation with Geant4 and discuss the results

  20. Investigation of radial dose effect on single event upset cross-section due to heavy ions using GEANT4

    International Nuclear Information System (INIS)

    Boorboor, S.; Feghhi, S.A.H.; Jafari, H.

    2015-01-01

    The heavy ions are the main cause to produce single event upset (SEU) damage on electronic devices since they are high LET radiations. The dimension of electronic components in new technology, arise a challenge in radiation effect estimations. Accurate investigations require fully considering the ion track in energy deposition as a radial dose distribution. In this work, the distribution of delta rays as well as LET have been calculated to determine ionization structure around ion track by a Monte Carlo code, GEANT4. The radial dose of several heavy ions with different energy in silicon was investigated and compared with the works by other authors in this field. The results showed that heavy ions with identical LET can have different SEU cross-section in silicon transistors. As a demonstrative example, according to our results, the error probability for 4.8 GeV iron was 8 times greater than that for 15 MeV carbon ions, in transistors with new process technology which have small dimension and low critical charges. Our results show that considering radial dose distribution considerably improves the accuracy of the SEU cross-section estimation in electronic devices especially for new technologies. - Highlights: • The single event upset is produced by heavy ions interaction on electronic devices. • The radial dose of several heavy ions in silicon was calculated by GEANT4. • Heavy ions with identical LET had different SEU cross-section in silicon transistors. • Low dimension and critical charge devices were more sensitive to radial dose effect

  1. Creation of a Geant4 Muon Tomography Package for Imaging of Nuclear Fuel in Dry Cask Storage

    Energy Technology Data Exchange (ETDEWEB)

    Tsoukalas, Lefteri H. [Purdue Univ., West Lafayette, IN (United States)

    2016-03-01

    This is the final report of the NEUP project “Creation of a Geant4 Muon Tomography Package for Imaging of Nuclear Fuel in Dry Cask Storage”, DE-NE0000695. The project started on December 1, 2013 and this report covers the period December 1, 2013 through November 30, 2015. The project was successfully completed and this report provides an overview of the main achievements, results and findings throughout the duration of the project. Additional details can be found in the main body of this report and on the individual Quarterly Reports and associated Deliverables of the project, uploaded in PICS-NE.

  2. Quantification of the validity of simulations based on Geant4 and FLUKA for photo-nuclear interactions in the high energy range

    Science.gov (United States)

    Quintieri, Lina; Pia, Maria Grazia; Augelli, Mauro; Saracco, Paolo; Capogni, Marco; Guarnieri, Guido

    2017-09-01

    Photo-nuclear interactions are relevant in many research fields of both fundamental and applied physics and, for this reason, accurate Monte Carlo simulations of photo-nuclear interactions can provide a valuable and indispensable support in a wide range of applications (i.e from the optimisation of photo-neutron source target to the dosimetric estimation in high energy accelerator, etc). Unfortunately, few experimental photo-nuclear data are available above 100 MeV, so that, in the high energy range (from hundreds of MeV up to GeV scale), the code predictions are based on physical models. The aim of this work is to compare the predictions of relevant observables involving photon-nuclear interaction modelling, obtained with GEANT4 and FLUKA, to experimental data (if available), in order to assess the code estimation reliability, over a wide energy range. In particular, the comparison of the estimated photo-neutron yields and energy spectra with the experimental results of the n@BTF experiment (carried out at the Beam Test Facility of DaΦne collider, in Frascati, Italy) is here reported and discussed. Moreover, the preliminary results of the comparison of the cross sections used in the codes with the"evaluated' data recommended by the IAEA are also presented for some selected cases (W, Pb, Zn).

  3. Modelling of the dose-rate variations with depth in the Martian regolith using GEANT4

    International Nuclear Information System (INIS)

    Morthekai, P.; Jain, M.; Dartnell, L.; Murray, A.S.; Botter-Jensen, L.; Desorgher, L.

    2007-01-01

    The environmental radiation field at the Martian surface consists mainly of Galactic Cosmic Rays (GCR) and charged particles ejected during the Solar Particle Events (SPE). Interactions between these radiation fluxes and the regolith result in a complex radiation field that varies both as a function of depth and time and can only be quantified using radiation transport models. We first describe here the main issues and constraints in deriving Martian dose rates. Preliminary results, obtained using the GEANT4 Monte Carlo simulation tool kit, suggest the surface dose rate is ∼63 mGy a -1 during quiet periods in solar activity. The accuracy of the model predictions has been tested by comparison with published observations of cosmic ray dose-rate variation in the Earth's atmosphere

  4. Geant4 simulation of ion chambers response to 60Co spectrum of LNMRI/IRD Shepherd 81-14D Radiator

    Science.gov (United States)

    Queiroz Filho, P. P.; Da Silva, C. N. M.

    2018-03-01

    The National Ionizing Radiation Metrology Laboratory of the Radioprotection and Dosimetry Institute (LNMRI / IRD) has recently acquired a Shepherd 81-14D Radiator. In this work we simulate, using Geant4, the behavior with the inverse square law radiation for 3 models of PTW spherical chambers used in radioprotection, a relevant information to planning the measurements. We did the corrections for the attenuation and scattering in the air for each distance, where we used the 60Co spectrum simulated previously.

  5. A fast and complete GEANT4 and ROOT Object-Oriented Toolkit: GROOT

    Science.gov (United States)

    Lattuada, D.; Balabanski, D. L.; Chesnevskaya, S.; Costa, M.; Crucillà, V.; Guardo, G. L.; La Cognata, M.; Matei, C.; Pizzone, R. G.; Romano, S.; Spitaleri, C.; Tumino, A.; Xu, Y.

    2018-01-01

    Present and future gamma-beam facilities represent a great opportunity to validate and evaluate the cross-sections of many photonuclear reactions at near-threshold energies. Monte Carlo (MC) simulations are very important to evaluate the reaction rates and to maximize the detection efficiency but, unfortunately, they can be very cputime-consuming and in some cases very hard to reproduce, especially when exploring near-threshold cross-section. We developed a software that makes use of the validated tracking GEANT4 libraries and the n-body event generator of ROOT in order to provide a fast, realiable and complete MC tool to be used for nuclear physics experiments. This tool is indeed intended to be used for photonuclear reactions at γ-beam facilities with ELISSA (ELI Silicon Strip Array), a new detector array under development at the Extreme Light Infrastructure - Nuclear Physics (ELI-NP). We discuss the results of MC simulations performed to evaluate the effects of the electromagnetic induced background, of the straggling due to the target thickness and of the resolution of the silicon detectors.

  6. Modeling the tagged-neutron UXO identification technique using the Geant4 toolkit

    International Nuclear Information System (INIS)

    Zhou, Y.; Zhu, X.; Wang, Y.; Mitra, S.

    2012-01-01

    It is proposed to use 14 MeV neutrons tagged by the associated particle neutron time-of-flight technique (APnTOF) to identify the fillers of unexploded ordnances (UXO) by characterizing their carbon, nitrogen and oxygen contents. To facilitate the design and construction of a prototype system, a preliminary simulation model was developed, using the Geant4 toolkit. This work established the toolkit environment for (a) generating tagged neutrons, (b) their transport and interactions within a sample to induce emission and detection of characteristic gamma-rays, and (c) 2D and 3D-image reconstruction of the interrogated object using the neutron and gamma-ray time-of-flight information. Using the modeling, this article demonstrates the novelty of the tagged-neutron approach for extracting useful signals with high signal-to-background discrimination of an object-of-interest from that of its environment. Simulations indicated that an UXO filled with the RDX explosive, hexogen (C 3 H 6 O 6 N 6 ), can be identified to a depth of 20 cm when buried in soil. (author)

  7. Simulations of the Response of the Cluster Detector/Scintillator Wall for the 4π facility at SIS/ESR using the GEANT Detector program

    International Nuclear Information System (INIS)

    Herrmann, N.; Maguire, C.F.; Cerruti, C.; Coffin, J.P.; Fintz, P.; Guillaume, G.; Jundt, F.; Rami, F.; Tezkratt, R.; Wagner, P.

    1990-01-01

    The expected response of the cluster detector/scintillator wall of the SIS/ESR 4π facility has been investigated with the use of the GEANT detector program and the FREESCO event generator code. Results are presented and discussed. It is shown in particular that the efficiency of the track reconstruction method should be acceptable

  8. Simulation Loop between CAD systems, Geant4 and GeoModel: Implementation and Results

    CERN Document Server

    Sharmazanashvili, Alexander; The ATLAS collaboration

    2015-01-01

    Data_vs_MonteCarlo discrepancy is one of the most important field of investigation for ATLAS simulation studies. There are several reasons of above mentioned discrepancies but primary interest is falling on geometry studies and investigation of how geometry descriptions of detector in simulation adequately representing “as-built” descriptions. Shapes consistency and detalization is not important while adequateness of volumes and weights of detector components are essential for tracking. There are 2 main reasons of faults of geometry descriptions in simulation: 1/ Inconsistency to “as-built” geometry descriptions; 2/Internal inaccuracies of transactions added by simulation packages itself. Georgian Engineering team developed hub on the base of CATIA platform and several tools enabling to read in CATIA different descriptions used by simulation packages, like XML/Persint->CATIA; IV/VP1->CATIA; GeoModel->CATIA; Geant4->CATIA. As a result it becomes possible to compare different descriptions with each othe...

  9. Geant4 simulation of the CERN-EU high-energy reference field (CERF) facility.

    Science.gov (United States)

    Prokopovich, D A; Reinhard, M I; Cornelius, I M; Rosenfeld, A B

    2010-09-01

    The CERN-EU high-energy reference field facility is used for testing and calibrating both active and passive radiation dosemeters for radiation protection applications in space and aviation. Through a combination of a primary particle beam, target and a suitable designed shielding configuration, the facility is able to reproduce the neutron component of the high altitude radiation field relevant to the jet aviation industry. Simulations of the facility using the GEANT4 (GEometry ANd Tracking) toolkit provide an improved understanding of the neutron particle fluence as well as the particle fluence of other radiation components present. The secondary particle fluence as a function of the primary particle fluence incident on the target and the associated dose equivalent rates were determined at the 20 designated irradiation positions available at the facility. Comparisons of the simulated results with previously published simulations obtained using the FLUKA Monte Carlo code, as well as with experimental results of the neutron fluence obtained with a Bonner sphere spectrometer, are made.

  10. Geant4 simulation of the response of phosphor screens for X-ray imaging

    International Nuclear Information System (INIS)

    Pistrui-Maximean, S.A.; Freud, N.; Letang, J.M.; Koch, A.; Munier, B.; Walenta, A.H.; Montarou, G.; Babot, D.

    2006-01-01

    In order to predict and optimize the response of phosphor screens, it is important to understand the role played by the different physical processes inside the scintillator layer. A simulation model based on the Monte Carlo code Geant4 was developed to determine the Modulation Transfer Function (MTF) of phosphor screens for energies used in X-ray medical imaging and nondestructive testing applications. The visualization of the dose distribution inside the phosphor layer gives an insight into how the MTF is progressively degraded by X-ray and electron transport. The simulation model allows to study the influence of physical and technological parameters on the detector performances, as well as to design and optimize new detector configurations. Preliminary MTF measurements have been carried out and agreement with experimental data has been found in the case of a commercial screen (Kodak Lanex Fine) at an X-ray tube potential of 100 kV. Further validation with other screens (transparent or granular) at different energies is under way

  11. Geant4 simulation of the response of phosphor screens for X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pistrui-Maximean, S.A. [Laboratory of Nondestructive Testing using Ionizing Radiation, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint Exupery, 69621 Villeurbanne Cedex (France)]. E-mail: simona.pistrui@insa-lyon.fr; Freud, N. [Laboratory of Nondestructive Testing using Ionizing Radiation, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint Exupery, 69621 Villeurbanne Cedex (France); Letang, J.M. [Laboratory of Nondestructive Testing using Ionizing Radiation, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint Exupery, 69621 Villeurbanne Cedex (France); Koch, A. [Thales Electron Devices, 38430 Moirans (France); Munier, B. [Thales Electron Devices, 38430 Moirans (France); Walenta, A.H. [Department of Detectors and Electronics, FB Physik, University of Siegen, 57068 Siegen (Germany); Montarou, G. [Corpuscular Physics Laboratory, Blaise Pascal University, 63177 Aubiere Cedex (France); Babot, D. [Laboratory of Nondestructive Testing using Ionizing Radiation, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint Exupery, 69621 Villeurbanne Cedex (France)

    2006-07-01

    In order to predict and optimize the response of phosphor screens, it is important to understand the role played by the different physical processes inside the scintillator layer. A simulation model based on the Monte Carlo code Geant4 was developed to determine the Modulation Transfer Function (MTF) of phosphor screens for energies used in X-ray medical imaging and nondestructive testing applications. The visualization of the dose distribution inside the phosphor layer gives an insight into how the MTF is progressively degraded by X-ray and electron transport. The simulation model allows to study the influence of physical and technological parameters on the detector performances, as well as to design and optimize new detector configurations. Preliminary MTF measurements have been carried out and agreement with experimental data has been found in the case of a commercial screen (Kodak Lanex Fine) at an X-ray tube potential of 100 kV. Further validation with other screens (transparent or granular) at different energies is under way.

  12. Validation of Geant4 fragmentation for Heavy Ion Therapy

    Science.gov (United States)

    Bolst, David; Cirrone, Giuseppe A. P.; Cuttone, Giacomo; Folger, Gunter; Incerti, Sebastien; Ivanchenko, Vladimir; Koi, Tatsumi; Mancusi, Davide; Pandola, Luciano; Romano, Francesco; Rosenfeld, Anatoly B.; Guatelli, Susanna

    2017-10-01

    12C ion therapy has had growing interest in recent years for its excellent dose conformity. However at therapeutic energies, which can be as high as 400 MeV/u, carbon ions produce secondary fragments. For an incident 400 MeV/u 12C ion beam, ∼ 70 % of the beam will undergo fragmentation before the Bragg Peak. The dosimetric and radiobiological impact of these fragments must be accurately characterised, as it can result in increasing the risk of secondary cancer for the patient as well as altering the relative biological effectiveness. This work investigates the accuracy of three different nuclear fragmentation models available in the Monte Carlo Toolkit Geant4, the Binary Intranuclear Cascade (BIC), the Quantum Molecular Dynamics (QMD) and the Liege Intranuclear Cascade (INCL++). The models were benchmarked against experimental data for a pristine 400 MeV/u 12C beam incident upon a water phantom, including fragment yield, angular and energy distribution. For fragment yields the three alternative models agreed between ∼ 5 and ∼ 35 % with experimental measurements, the QMD using the "Frag" option gave the best agreement for lighter fragments but had reduced agreement for larger fragments. For angular distributions INCL++ was seen to provide the best agreement among the models for all elements with the exception of Hydrogen, while BIC and QMD was seen to produce broader distributions compared to experiment. BIC and QMD performed similar to one another for kinetic energy distributions while INCL++ suffered from producing lower energy distributions compared to the other models and experiment.

  13. Geant4 simulations of soft proton scattering in X-ray optics. A tentative validation using laboratory measurements

    Science.gov (United States)

    Fioretti, Valentina; Mineo, Teresa; Bulgarelli, Andrea; Dondero, Paolo; Ivanchenko, Vladimir; Lei, Fan; Lotti, Simone; Macculi, Claudio; Mantero, Alfonso

    2017-12-01

    Low energy protons (process responsible for the grazing angle scattering processes is mandatory to evaluate the impact of such events on the performance (e.g. observation time, sensitivity) of future X-ray telescopes as the ESA ATHENA mission. The Remizovich model describes particles reflected by solids at glancing angles in terms of the Boltzmann transport equation using the diffuse approximation and the model of continuous slowing down in energy. For the first time this solution, in the approximation of no energy losses, is implemented, verified, and qualitatively validated on top of the Geant4 release 10.2, with the possibility to add a constant energy loss to each interaction. This implementation is verified by comparing the simulated proton distribution to both the theoretical probability distribution and with independent ray-tracing simulations. Both the new scattering physics and the Coulomb scattering already built in the official Geant4 distribution are used to reproduce the latest experimental results on grazing angle proton scattering. At 250 keV multiple scattering delivers large proton angles and it is not consistent with the observation. Among the tested models, the single scattering seems to better reproduce the scattering efficiency at the three energies but energy loss obtained at small scattering angles is significantly lower than the experimental values. In general, the energy losses obtained in the experiment are higher than what obtained by the simulation. The experimental data are not completely representative of the soft proton scattering experienced by current X-ray telescopes because of the lack of measurements at low energies (distribution at the exit of X-ray optics.

  14. Implementation of a model in Geant4 of an accelerator on Cloudmc, a Web application for the parallelization of Monte Carlo simulations in the Cloud

    International Nuclear Information System (INIS)

    Miras del Rio, H.; Jimenez Marrufo, R.; Cortes Giraldo, M. A.; Miras del Rio, C.

    2013-01-01

    This paper describes the implementation in CloudMC of a simulation program MC, based on the code of Geant4, a Siemens Accelerator model Oncor with the intention that in future can be used for calculation of radiation treatments with MC in short periods of time. (Author)

  15. Deposição da calda na cultura da soja em função de diferentes pressões de trabalho e pontas de pulverização

    OpenAIRE

    Cunha, João Paulo Arantes Rodrigues da; Marques, Rodrigo Santos; Alves, Guilherme Sousa

    2016-01-01

    RESUMO A pressão de trabalho influencia as características da pulverização hidráulica de produtos fitossanitários e pode alterar a penetração da calda no dossel da cultura da soja. Este trabalho teve como objetivo avaliar o efeito da pressão na deposição de calda em plantas de soja, promovida por diferentes modelos de pontas de pulverização. O experimento foi conduzido em delineamento de blocos ao acaso, em esquema fatorial 2 x 4 + 1, sendo duas pontas de pulverização (jato cônico vazio - ATR...

  16. Validation of GEANT4 Monte Carlo Models with a Highly Granular Scintillator-Steel Hadron Calorimeter

    CERN Document Server

    Adloff, C.; Blaising, J.J.; Drancourt, C.; Espargiliere, A.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Prast, J.; Vouters, G.; Francis, K.; Repond, J.; Schlereth, J.; Smith, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Buanes, T.; Eigen, G.; Mikami, Y.; Watson, N.K.; Mavromanolakis, G.; Thomson, M.A.; Ward, D.R.; Yan, W.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dotti, A.; Folger, G.; Ivantchenko, V.; Uzhinskiy, V.; Benyamna, M.; Cârloganu, C.; Fehr, F.; Gay, P.; Manen, S.; Royer, L.; Blazey, G.C.; Dyshkant, A.; Lima, J.G.R.; Zutshi, V.; Hostachy, J.Y.; Morin, L.; Cornett, U.; David, D.; Falley, G.; Gadow, K.; Gottlicher, P.; Gunter, C.; Hermberg, B.; Karstensen, S.; Krivan, F.; Lucaci-Timoce, A.I.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Vargas-Trevino, A.; Feege, N.; Garutti, E.; Marchesini, I.; Ramilli, M.; Eckert, P.; Harion, T.; Kaplan, A.; Schultz-Coulon, H.Ch.; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Dauncey, P.D.; Magnan, A.M.; Bartsch, V.; Wing, M.; Salvatore, F.; Alamillo, E.Calvo; Fouz, M.C.; Puerta-Pelayo, J.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Kirikova, N.; Kozlov, V.; Smirnov, P.; Soloviev, Y.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Tikhomirov, V.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Callier, S.; Conforti di Lorenzo, S.; Cornebise, P.; Doublet, Ph.; Dulucq, F.; Fleury, J.; Frisson, T.; van der Kolk, N.; Li, H.; Martin-Chassard, G.; Richard, F.; de la Taille, Ch.; Poschl, R.; Raux, L.; Rouene, J.; Seguin-Moreau, N.; Anduze, M.; Boudry, V.; Brient, J-C.; Jeans, D.; Mora de Freitas, P.; Musat, G.; Reinhard, M.; Ruan, M.; Videau, H.; Bulanek, B.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Takeshita, T.; Uozumi, S.; Gotze, M.; Hartbrich, O.; Sauer, J.; Weber, S.; Zeitnitz, C.

    2013-01-01

    Calorimeters with a high granularity are a fundamental requirement of the Particle Flow paradigm. This paper focuses on the prototype of a hadron calorimeter with analog readout, consisting of thirty-eight scintillator layers alternating with steel absorber planes. The scintillator plates are finely segmented into tiles individually read out via Silicon Photomultipliers. The presented results are based on data collected with pion beams in the energy range from 8GeV to 100GeV. The fine segmentation of the sensitive layers and the high sampling frequency allow for an excellent reconstruction of the spatial development of hadronic showers. A comparison between data and Monte Carlo simulations is presented, concerning both the longitudinal and lateral development of hadronic showers and the global response of the calorimeter. The performance of several GEANT4 physics lists with respect to these observables is evaluated.

  17. Geant4 simulation of ion chambers response to {sup 60}Co spectrum of LNMRI/IRD Shepherd 81-14D Radiator

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz Filho, P.P.; Silva, C.N.M. da, E-mail: queiroz@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The National Ionizing Radiation Metrology Laboratory of the Radioprotection and Dosimetry Institute (LNMRI / IRD) has recently acquired a Shepherd 81-14D Radiator. In this work we simulate, using Geant4, the behavior with the inverse square law radiation of the distance for 3 models of PTW spherical chambers used in radioprotection, a relevant information to planning the measurements. We did the corrections for the attenuation and scattering in the air for each distance, where we used the {sup 60}Co spectrum simulated previously. (author)

  18. First results of saturation curve measurements of heat-resistant steel using GEANT4 and MCNP5 codes

    International Nuclear Information System (INIS)

    Hoang, Duc-Tam; Tran, Thien-Thanh; Le, Bao-Tran; Vo, Hoang-Nguyen; Chau, Van-Tao; Tran, Kim-Tuyet; Huynh, Dinh-Chuong

    2015-01-01

    A gamma backscattering technique is applied to calculate the saturation curve and the effective mass attenuation coefficient of material. A NaI(Tl) detector collimated by collimator of large diameter is modeled by Monte Carlo technique using both MCNP5 and GEANT4 codes. The result shows a good agreement in response function of the scattering spectra for the two codes. Based on such spectra, the saturation curve of heat-resistant steel is determined. The results represent a strong confirmation that it is appropriate to use the detector collimator of large diameter to obtain the scattering spectra and this work is also the basis of experimental set-up for determining the thickness of material. (author)

  19. The simulation of an imaging gamma-ray Compton backscattering device using GEANT4

    International Nuclear Information System (INIS)

    Flechas, D.; Cristancho, F.; Sarmiento, L.G.; Fajardo, E.

    2014-01-01

    A gamma-backscattering imaging device dubbed Compton Camera, developed at GSI (Darmstadt, Germany) and modified and studied at the Nuclear Physics Group of the National University of Colombia in Bogota, uses the back-to-back emission of two gamma rays in the positron annihilation to construct a bidimensional image that represents the distribution of matter in the field-of-view of the camera. This imaging capability can be used in a host of different situations, for example, to identify and study deposition and structural defects, and to help locating concealed objects, to name just two cases. In order to increase the understanding of the response of the Compton Camera and, in particular, its image formation process, and to assist in the data analysis, a simulation of the camera was developed using the GEANT4 simulation toolkit. In this work, the images resulting from different experimental conditions are shown. The simulated images and their comparison with the experimental ones already suggest methods to improve the present experimental device. (author)

  20. Geant4 simulation of gamma conversion to muon pair for dark matter searches

    CERN Document Server

    Sokolov, Anton

    2017-01-01

    There is a direct evidence from different astronomical observations and CMB spectrum that 26% of the visible part of the Universe consists of so-called dark matter. There are many models explaining the phenomenon of dark matter, however none of them has been confirmed experimentally. It justifies the further searches for the dark matter that involve more and more various experiments, such as, for instance, SHiP experiment [1] at CERN or LDMX project [2] at SLAC. LDMX (Light Dark Matter eXperiment) is an electron fixedtarget missing momentum search for light dark matter. The main process that LDMX looks for is dark bremsstrahlung (i.e. emitting a light dark matter particle) by the several GeV electrons scattered off the target. This process is contaminated by the background of ordinary bremsstrahlung, that consists of many different processes which can be accounted for and vetoed by various counters. The experiment designs are studied with the Geant4 toolkit. Recently, one of the important background pro...

  1. Comparison of Geant4 multiple Coulomb scattering models with theory for radiotherapy protons.

    Science.gov (United States)

    Makarova, Anastasia; Gottschalk, Bernard; Sauerwein, Wolfgang

    2017-07-06

    Usually, Monte Carlo models are validated against experimental data. However, models of multiple Coulomb scattering (MCS) in the Gaussian approximation are exceptional in that we have theories which are probably more accurate than the experiments which have, so far, been done to test them. In problems directly sensitive to the distribution of angles leaving the target, the relevant theory is the Molière/Fano/Hanson variant of Molière theory (Gottschalk et al 1993 Nucl. Instrum. Methods Phys. Res. B 74 467-90). For transverse spreading of the beam in the target itself, the theory of Preston and Koehler (Gottschalk (2012 arXiv:1204.4470)) holds. Therefore, in this paper we compare Geant4 simulations, using the Urban and Wentzel models of MCS, with theory rather than experiment, revealing trends which would otherwise be obscured by experimental scatter. For medium-energy (radiotherapy) protons, and low-Z (water-like) target materials, Wentzel appears to be better than Urban in simulating the distribution of outgoing angles. For beam spreading in the target itself, the two models are essentially equal.

  2. Performance of GeantV EM Physics Models

    Energy Technology Data Exchange (ETDEWEB)

    Amadio, G.; et al.

    2016-10-14

    The recent progress in parallel hardware architectures with deeper vector pipelines or many-cores technologies brings opportunities for HEP experiments to take advantage of SIMD and SIMT computing models. Launched in 2013, the GeantV project studies performance gains in propagating multiple particles in parallel, improving instruction throughput and data locality in HEP event simulation on modern parallel hardware architecture. Due to the complexity of geometry description and physics algorithms of a typical HEP application, performance analysis is indispensable in identifying factors limiting parallel execution. In this report, we will present design considerations and preliminary computing performance of GeantV physics models on coprocessors (Intel Xeon Phi and NVidia GPUs) as well as on mainstream CPUs.

  3. Performance of GeantV EM Physics Models

    Science.gov (United States)

    Amadio, G.; Ananya, A.; Apostolakis, J.; Aurora, A.; Bandieramonte, M.; Bhattacharyya, A.; Bianchini, C.; Brun, R.; Canal, P.; Carminati, F.; Cosmo, G.; Duhem, L.; Elvira, D.; Folger, G.; Gheata, A.; Gheata, M.; Goulas, I.; Iope, R.; Jun, S. Y.; Lima, G.; Mohanty, A.; Nikitina, T.; Novak, M.; Pokorski, W.; Ribon, A.; Seghal, R.; Shadura, O.; Vallecorsa, S.; Wenzel, S.; Zhang, Y.

    2017-10-01

    The recent progress in parallel hardware architectures with deeper vector pipelines or many-cores technologies brings opportunities for HEP experiments to take advantage of SIMD and SIMT computing models. Launched in 2013, the GeantV project studies performance gains in propagating multiple particles in parallel, improving instruction throughput and data locality in HEP event simulation on modern parallel hardware architecture. Due to the complexity of geometry description and physics algorithms of a typical HEP application, performance analysis is indispensable in identifying factors limiting parallel execution. In this report, we will present design considerations and preliminary computing performance of GeantV physics models on coprocessors (Intel Xeon Phi and NVidia GPUs) as well as on mainstream CPUs.

  4. Performance of GeantV EM Physics Models

    CERN Document Server

    Amadio, G; Apostolakis, J; Aurora, A; Bandieramonte, M; Bhattacharyya, A; Bianchini, C; Brun, R; Canal P; Carminati, F; Cosmo, G; Duhem, L; Elvira, D; Folger, G; Gheata, A; Gheata, M; Goulas, I; Iope, R; Jun, S Y; Lima, G; Mohanty, A; Nikitina, T; Novak, M; Pokorski, W; Ribon, A; Seghal, R; Shadura, O; Vallecorsa, S; Wenzel, S; Zhang, Y

    2017-01-01

    The recent progress in parallel hardware architectures with deeper vector pipelines or many-cores technologies brings opportunities for HEP experiments to take advantage of SIMD and SIMT computing models. Launched in 2013, the GeantV project studies performance gains in propagating multiple particles in parallel, improving instruction throughput and data locality in HEP event simulation on modern parallel hardware architecture. Due to the complexity of geometry description and physics algorithms of a typical HEP application, performance analysis is indispensable in identifying factors limiting parallel execution. In this report, we will present design considerations and preliminary computing performance of GeantV physics models on coprocessors (Intel Xeon Phi and NVidia GPUs) as well as on mainstream CPUs.

  5. A polygon-surface reference Korean male phantom (PSRK-Man) and its direct implementation in Geant4 Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Hyeong; Jeong, Jong Hwi [Department of Nuclear Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Bolch, Wesley E [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Cho, Kun-Woo [Korea Institute of Nuclear Safety, 19 Guseong-dong, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Hwang, Sung Bae, E-mail: chkim@hanyang.ac.kr [Department of Physical Therapy, Kyungbuk College, Hyucheon 2-dong, Yeongju-si, Gyeongbuk 750-712 (Korea, Republic of)

    2011-05-21

    Even though the hybrid phantom embodies both the anatomic reality of voxel phantoms and the deformability of stylized phantoms, it must be voxelized to be used in a Monte Carlo code for dose calculation or some imaging simulation, which incurs the inherent limitations of voxel phantoms. In the present study, a voxel phantom named VKH-Man (Visible Korean Human-Man), was converted to a polygon-surface phantom (PSRK-Man, Polygon-Surface Reference Korean-Man), which was then adjusted to the Reference Korean data. Subsequently, the PSRK-Man polygon phantom was directly, without any voxelization process, implemented in the Geant4 Monte Carlo code for dose calculations. The calculated dose values and computation time were then compared with those of HDRK-Man (High Definition Reference Korean-Man), a corresponding voxel phantom adjusted to the same Reference Korean data from the same VKH-Man voxel phantom. Our results showed that the calculated dose values of the PSRK-Man surface phantom agreed well with those of the HDRK-Man voxel phantom. The calculation speed for the PSRK-Man polygon phantom though was 70-150 times slower than that of the HDRK-Man voxel phantom; that speed, however, could be acceptable in some applications, in that direct use of the surface phantom PSRK-Man in Geant4 does not require a separate voxelization process. Computing speed can be enhanced, in future, either by optimizing the Monte Carlo transport kernel for the polygon surfaces or by using modern computing technologies such as grid computing and general-purpose computing on graphics processing units programming.

  6. A polygon-surface reference Korean male phantom (PSRK-Man) and its direct implementation in Geant4 Monte Carlo simulation

    International Nuclear Information System (INIS)

    Kim, Chan Hyeong; Jeong, Jong Hwi; Bolch, Wesley E; Cho, Kun-Woo; Hwang, Sung Bae

    2011-01-01

    Even though the hybrid phantom embodies both the anatomic reality of voxel phantoms and the deformability of stylized phantoms, it must be voxelized to be used in a Monte Carlo code for dose calculation or some imaging simulation, which incurs the inherent limitations of voxel phantoms. In the present study, a voxel phantom named VKH-Man (Visible Korean Human-Man), was converted to a polygon-surface phantom (PSRK-Man, Polygon-Surface Reference Korean-Man), which was then adjusted to the Reference Korean data. Subsequently, the PSRK-Man polygon phantom was directly, without any voxelization process, implemented in the Geant4 Monte Carlo code for dose calculations. The calculated dose values and computation time were then compared with those of HDRK-Man (High Definition Reference Korean-Man), a corresponding voxel phantom adjusted to the same Reference Korean data from the same VKH-Man voxel phantom. Our results showed that the calculated dose values of the PSRK-Man surface phantom agreed well with those of the HDRK-Man voxel phantom. The calculation speed for the PSRK-Man polygon phantom though was 70-150 times slower than that of the HDRK-Man voxel phantom; that speed, however, could be acceptable in some applications, in that direct use of the surface phantom PSRK-Man in Geant4 does not require a separate voxelization process. Computing speed can be enhanced, in future, either by optimizing the Monte Carlo transport kernel for the polygon surfaces or by using modern computing technologies such as grid computing and general-purpose computing on graphics processing units programming.

  7. BCD/CPS: An event-level GEANT3 parallelization via CPS

    International Nuclear Information System (INIS)

    Roberts, L.A.

    1991-04-01

    BCD/CPS is an implementation of the Bottom Collider Detector GEANT3 simulation for CPS processor ranches. BCD/CPS demonstrates some of the capabilities of event-parallel applications applicable to current SSC detector simulations using the CPS and CZ/CPS communications protocols. Design, implementation and usage of the BCD/CPS simulation are presented along with extensive source listings for novice GEANT3/CPS programmers. 11 refs

  8. Modeling the TrueBeam linac using a CAD to Geant4 geometry implementation: Dose and IAEA-compliant phase space calculations

    International Nuclear Information System (INIS)

    Constantin, Magdalena; Perl, Joseph; LoSasso, Tom; Salop, Arthur; Whittum, David; Narula, Anisha; Svatos, Michelle; Keall, Paul J.

    2011-01-01

    Purpose: To create an accurate 6 MV Monte Carlo simulation phase space for the Varian TrueBeam treatment head geometry imported from cad (computer aided design) without adjusting the input electron phase space parameters. Methods: geant4 v4.9.2.p01 was employed to simulate the 6 MV beam treatment head geometry of the Varian TrueBeam linac. The electron tracks in the linear accelerator were simulated with Parmela, and the obtained electron phase space was used as an input to the Monte Carlo beam transport and dose calculations. The geometry components are tessellated solids included in geant4 as gdml (generalized dynamic markup language) files obtained via STEP (standard for the exchange of product) export from Pro/Engineering, followed by STEP import in Fastrad, a STEP-gdml converter. The linac has a compact treatment head and the small space between the shielding collimator and the divergent arc of the upper jaws forbids the implementation of a plane for storing the phase space. Instead, an IAEA (International Atomic Energy Agency) compliant phase space writer was implemented on a cylindrical surface. The simulation was run in parallel on a 1200 node Linux cluster. The 6 MV dose calculations were performed for field sizes varying from 4 x 4 to 40 x 40 cm 2 . The voxel size for the 60x60x40 cm 3 water phantom was 4x4x4 mm 3 . For the 10x10 cm 2 field, surface buildup calculations were performed using 4x4x2 mm 3 voxels within 20 mm of the surface. Results: For the depth dose curves, 98% of the calculated data points agree within 2% with the experimental measurements for depths between 2 and 40 cm. For depths between 5 and 30 cm, agreement within 1% is obtained for 99% (4x4), 95% (10x10), 94% (20x20 and 30x30), and 89% (40x40) of the data points, respectively. In the buildup region, the agreement is within 2%, except at 1 mm depth where the deviation is 5% for the 10x10 cm 2 open field. For the lateral dose profiles, within the field size for fields up to 30x30 cm 2

  9. Modeling the TrueBeam linac using a CAD to Geant4 geometry implementation: Dose and IAEA-compliant phase space calculations

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, Magdalena; Perl, Joseph; LoSasso, Tom; Salop, Arthur; Whittum, David; Narula, Anisha; Svatos, Michelle; Keall, Paul J. [Department of Radiation Oncology, Radiation Physics Division, Stanford University, Stanford, California 94304 (United States); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Memorial Sloan-Kettering Cancer Center, New York 10021 (United States); Varian Medical Systems, Inc., Palo Alto, California 94304 (United States); Department of Radiation Oncology, Radiation Physics Division, Stanford University, Stanford, California 94304 (United States)

    2011-07-15

    Purpose: To create an accurate 6 MV Monte Carlo simulation phase space for the Varian TrueBeam treatment head geometry imported from cad (computer aided design) without adjusting the input electron phase space parameters. Methods: geant4 v4.9.2.p01 was employed to simulate the 6 MV beam treatment head geometry of the Varian TrueBeam linac. The electron tracks in the linear accelerator were simulated with Parmela, and the obtained electron phase space was used as an input to the Monte Carlo beam transport and dose calculations. The geometry components are tessellated solids included in geant4 as gdml (generalized dynamic markup language) files obtained via STEP (standard for the exchange of product) export from Pro/Engineering, followed by STEP import in Fastrad, a STEP-gdml converter. The linac has a compact treatment head and the small space between the shielding collimator and the divergent arc of the upper jaws forbids the implementation of a plane for storing the phase space. Instead, an IAEA (International Atomic Energy Agency) compliant phase space writer was implemented on a cylindrical surface. The simulation was run in parallel on a 1200 node Linux cluster. The 6 MV dose calculations were performed for field sizes varying from 4 x 4 to 40 x 40 cm{sup 2}. The voxel size for the 60x60x40 cm{sup 3} water phantom was 4x4x4 mm{sup 3}. For the 10x10 cm{sup 2} field, surface buildup calculations were performed using 4x4x2 mm{sup 3} voxels within 20 mm of the surface. Results: For the depth dose curves, 98% of the calculated data points agree within 2% with the experimental measurements for depths between 2 and 40 cm. For depths between 5 and 30 cm, agreement within 1% is obtained for 99% (4x4), 95% (10x10), 94% (20x20 and 30x30), and 89% (40x40) of the data points, respectively. In the buildup region, the agreement is within 2%, except at 1 mm depth where the deviation is 5% for the 10x10 cm{sup 2} open field. For the lateral dose profiles, within the field size

  10. Study of x-ray fluorescence : Development in Geant4 of new models of cross sections for simulation PIXE. Biological and archaeological applications

    International Nuclear Information System (INIS)

    Ben Abdelouahed, Haifa

    2010-01-01

    a great number of times, that makes it possible to reproduce the macroscopic effects and to calculate sizes like, in our case, x-ray fluorescence. Among several tools available for Monte Carlo simulation of the interactions particle-matter, the tool for simulation Monte Carlo Geant4 is characterized by a particularly flexible architecture based on directed technology object. This is why, to build our code of simulation, our choice was fixed on the use of this tool. We treat in the first chapter the guiding principle of x-ray fluorescence, which leads us to present the various phenomena which limit its sensitivity of analysis. We devote the second chapter to the presentation of the Geant4 tool, and our tests of validation of its electromagnetic processes. We describe the performances and the limits of this tool as for the simulation of the cross sections. We will expose in this same chapter our development, in the Geant4 tool, of new models of calculation of the cross sections of ionization of the atoms by the protons and the particles alpha. We discuss also our method of validation of the models in question. This work was object of publication. It was taken into account by the Geant4 project: our development currently replaces the data base EEDL of Geant4 in the process of determination of the cross sections of ionization by charged particles, and makes thus functional the Geant4 tool in the simulation of the x-ray fluorescence induced by charged particles. We describe in the third chapter our use of the code worked out for the simulation of the effectiveness of absorption of the standard Si(Li) detector which constitutes the essential piece of our device of analysis by x-ray fluorescence. We expose the adopted approach which enabled us to optimize the geometrical parameters of the studied detector. This work was presented at the second international conference of spectroscopy. We present, in the fourth chapter, some examples of concrete applications on the study of

  11. Verification of Electromagnetic Physics Models for Parallel Computing Architectures in the GeantV Project

    Energy Technology Data Exchange (ETDEWEB)

    Amadio, G.; et al.

    2017-11-22

    An intensive R&D and programming effort is required to accomplish new challenges posed by future experimental high-energy particle physics (HEP) programs. The GeantV project aims to narrow the gap between the performance of the existing HEP detector simulation software and the ideal performance achievable, exploiting latest advances in computing technology. The project has developed a particle detector simulation prototype capable of transporting in parallel particles in complex geometries exploiting instruction level microparallelism (SIMD and SIMT), task-level parallelism (multithreading) and high-level parallelism (MPI), leveraging both the multi-core and the many-core opportunities. We present preliminary verification results concerning the electromagnetic (EM) physics models developed for parallel computing architectures within the GeantV project. In order to exploit the potential of vectorization and accelerators and to make the physics model effectively parallelizable, advanced sampling techniques have been implemented and tested. In this paper we introduce a set of automated statistical tests in order to verify the vectorized models by checking their consistency with the corresponding Geant4 models and to validate them against experimental data.

  12. Geant4 Hadronic Cascade Models and CMS Data Analysis : Computational Challenges in the LHC era

    CERN Document Server

    Heikkinen, Aatos

    This work belongs to the field of computational high-energy physics (HEP). The key methods used in this thesis work to meet the challenges raised by the Large Hadron Collider (LHC) era experiments are object-orientation with software engineering, Monte Carlo simulation, the computer technology of clusters, and artificial neural networks. The first aspect discussed is the development of hadronic cascade models, used for the accurate simulation of medium-energy hadron-nucleus reactions, up to 10 GeV. These models are typically needed in hadronic calorimeter studies and in the estimation of radiation backgrounds. Various applications outside HEP include the medical field (such as hadron treatment simulations), space science (satellite shielding), and nuclear physics (spallation studies). Validation results are presented for several significant improvements released in Geant4 simulation tool, and the significance of the new models for computing in the Large Hadron Collider era is estimated. In particular, we es...

  13. Influencia da aplicação de biofertilizantes na qualidade da produção da bananeira nanica (1º ciclo

    Directory of Open Access Journals (Sweden)

    Pedro B. Torres

    2014-04-01

    Full Text Available A agricultura orgânica é baseada em um sistema holístico, compatibilizando a produção de alimentos sem a utilização de insumos químicos na lavoura, aliado ao baixo custo de produção. Objetivou-se estudar os efeitos de tipos e doses de biofertilizantes na qualidade da produção da bananeira nanica (1º ciclo. Utilizou-se 5 tipos de biofertilizante e 10 doses de biofertilizantes (0; 0,3; 0,6; 0,9; 1,2; 1,5; 1,8; 2,1; 2,4 e 2,7 L planta-1 aplicação-1. A pesquisa foi conduzida, em condições de campo, no período de 20 de março de 2010 à maio de 2011, no CCHA da Universidade Estadual daParaíba, Campus Catolé do Rocha-PB. O delineamento experimental adotado foi o de blocos casualizados, com 50 tratamentos, no esquema fatorial 5 x 10, com quatro repetições, totalizando 200 plantas experimentais. Os maiores valores de diâmetro do fruto médio e diâmetro da polpa do fruto médio foram obtidos com a dose máxima de 2,7 L planta-1/aplicação-1 biofertilizante B1; O valor máximo do ºBrix da polpa do fruto médio foi obtido com a dose ótima do biofertilizante B4 (1,52 L planta-1/aplicação-1.

  14. Distributed Geant4 simulation in medical and space science applications using DIANE framework and the GRID

    CERN Document Server

    Moscicki, J T; Mantero, A; Pia, M G

    2003-01-01

    Distributed computing is one of the most important trends in IT which has recently gained significance for large-scale scientific applications. Distributed analysis environment (DIANE) is a R&D study, focusing on semiinteractive parallel and remote data analysis and simulation, which has been conducted at CERN. DIANE provides necessary software infrastructure for parallel scientific applications in the master-worker model. Advanced error recovery policies, automatic book-keeping of distributed jobs and on-line monitoring and control tools are provided. DIANE makes a transparent use of a number of different middleware implementations such as load balancing service (LSF, PBS, GRID Resource Broker, Condor) and security service (GSI, Kerberos, openssh). A number of distributed Geant 4 simulations have been deployed and tested, ranging from interactive radiotherapy treatment planning using dedicated clusters in hospitals, to globally-distributed simulations of astrophysics experiments using the European data g...

  15. Analysis of the dead layer of a detector of germanium with code ultrapure Monte Carlo SWORD-GEANT; Analisis del dead layer de un detector de germanio ultrapuro con el codigo de Monte Carlo SWORDS-GEANT

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, S.; Querol, A.; Ortiz, J.; Rodenas, J.; Verdu, G.

    2014-07-01

    In this paper the use of Monte Carlo code SWORD-GEANT is proposed to simulate an ultra pure germanium detector High Purity Germanium detector (HPGe) detector ORTEC specifically GMX40P4, coaxial geometry. (Author)

  16. New Standard Evaluated Neutron Cross Section Libraries for the GEANT4 Code and First Verification

    CERN Document Server

    Mendoza, Emilio; Koi, Tatsumi; Guerrero, Carlos

    2014-01-01

    The Monte Carlo simulation of the interaction of neutrons with matter relies on evaluated nuclear data libraries and models. The evaluated libraries are compilations of measured physical parameters (such as cross sections) combined with predictions of nuclear model calculations which have been adjusted to reproduce the experimental data. The results obtained from the simulations depend largely on the accuracy of the underlying nuclear data used, and thus it is important to have access to the nuclear data libraries available, either of general use or compiled for specific applications, and to perform exhaustive validations which cover the wide scope of application of the simulation code. In this paper we describe the work performed in order to extend the capabilities of the GEANT4 toolkit for the simulation of the interaction of neutrons with matter at neutron energies up to 20 MeV and a first verification of the results obtained. Such a work is of relevance for applications as diverse as the simulation of a n...

  17. Energy Response and Longitudinal Shower Profiles Measured in CMS HCAL and Comparison With Geant4

    CERN Document Server

    Baiatian, G; Emeliantchik, Igor; Massolov, V; Shumeiko, Nikolai; Stefanovich, R; Damgov, Jordan; Dimitrov, Lubomir; Genchev, Vladimir; Piperov, Stefan; Vankov, Ivan; Litov, Leander; Bencze, Gyorgy; Laszlo, Andras; Pal, Andras; Vesztergombi, Gyorgy; Zálán, Peter; Fenyvesi, Andras; Bawa, Harinder Singh; Beri, Suman Bala; Bhatnagar, Vipin; Kaur, Manjit; Kohli, Jatinder Mohan; Kumar, Arun; Singh, Jas Bir; Acharya, Bannaje Sripathi; Banerjee, Sunanda; Banerjee, Sudeshna; Chendvankar, Sanjay; Dugad, Shashikant; Kalmani, Suresh Devendrappa; Katta, S; Mazumdar, Kajari; Mondal, Naba Kumar; Nagaraj, P; Patil, Mandakini Ravindra; Reddy, L; Satyanarayana, B; Sharma, Seema; Sudhakar, Katta; Verma, Piyush; Hashemi, Majid; Mohammadi-Najafabadi, M; Paktinat, S; Golutvin, Igor; Kalagin, Vladimir; Kosarev, Ivan; Ladygin, Vladimir; Mescheryakov, G; Moissenz, P; Petrosian, A; Sergeyev, S; Smirnov, Vitaly; Vishnevskiy, Alexander; Volodko, Anton; Zarubin, Anatoli; Gavrilov, Vladimir; Gershtein, Yuri; Ilyina, N; Kaftanov, Vitali; Kisselevich, I; Kolossov, V; Krokhotin, Andrey; Kuleshov, Sergey; Litvintsev, Dmitri; Ulyanov, A; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Demianov, A; Gribushin, Andrey; Kodolova, Olga; Petrushanko, Sergey; Sarycheva, Ludmila; Teplov, V; Vardanyan, Irina; Yershov, A; Abramov, Victor; Goncharov, Petr; Kalinin, Alexey; Khmelnikov, Alexander; Korablev, Andrey; Korneev, Yury; Krinitsyn, Alexander; Kryshkin, V; Lukanin, Vladimir; Pikalov, Vladimir; Ryazanov, Anton; Talov, Vladimir; Turchanovich, L; Volkov, Alexey; Camporesi, Tiziano; De Visser, Theo; Vlassov, E; Aydin, Sezgin; Bakirci, Mustafa Numan; Cerci, Salim; Dumanoglu, Isa; Eskut, Eda; Kayis-Topaksu, A; Koylu, S; Kurt, Pelin; Onengüt, G; Ozkurt, Halil; Polatoz, A; Sogut, Kenan; Topakli, Huseyin; Vergili, Mehmet; Yetkin, Taylan; Cankocak, Kerem; Esendemir, Akif; Gamsizkan, Halil; Güler, M; Ozkan, Cigdem; Sekmen, Sezen; Serin-Zeyrek, M; Sever, Ramazan; Yazgan, Efe; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Dindar, Kamile; Gülmez, Erhan; Isiksal, Engin; Kaya, Mithat; Ozkorucuklu, Suat; Levchuk, Leonid; Sorokin, Pavel; Senchishin, V; Hauptman, John M; Abdullin, Salavat; Elias, John E; Elvira, D; Freeman, Jim; Green, Dan; Los, Serguei; O'Dell, Vivian; Ronzhin, Anatoly; Suzuki, Ichiro; Vidal, Richard; Whitmore, Juliana; Arcidy, M; Hazen, Eric; Heering, Arjan Hendrix; Lawlor, C; Lazic, Dragoslav; Machado, Emanuel; Rohlf, James; Varela, F; Wu, Shouxiang; Baden, Drew; Bard, Robert; Eno, Sarah Catherine; Grassi, Tullio; Jarvis, Chad; Kellogg, Richard G; Kunori, Shuichi; Mans, Jeremy; Skuja, Andris; Podrasky, V; Sanzeni, Christopher; Winn, Dave; Akgun, Ugur; Ayan, S; Duru, Firdevs; Merlo, Jean-Pierre; Mestvirishvili, Alexi; Miller, Michael; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Schmidt, Ianos; Akchurin, Nural; Carrell, Kenneth Wayne; Gumus, Kazim; Kim, Heejong; Spezziga, Mario; Thomas, Ray; Baarmand, Marc M; Mermerkaya, Hamit; Ralich, Robert; Vodopiyanov, Igor; Kramer, Laird; Linn, Stephan; Markowitz, Pete; Cushman, Priscilla; Ma, Yousi; Sherwood, Brian; Cremaldi, Lucien Marcus; Reidy, Jim; Sanders, David A; Karmgard, Daniel John; Ruchti, Randy; Fisher, Wade Cameron; Tully, Christopher; Bodek, Arie; De Barbaro, Pawel; Budd, Howard; Chung, Yeon Sei; Haelen, T; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Barnes, Virgil E; Laasanen, Alvin T

    2007-01-01

    The response of the CMS combined electromagnetic and hadron calorimeter to beams of pions with momenta in the range 5-300 GeV/c has been measured in the H2 test beam at CERN. The raw response with the electromagnetic compartment calibrated to electrons and the hadron compartment calibrated to 300 GeV pions may be represented by sigma = (1.2) sqrt{E} oplus (0.095) E. The fraction of energy visible in the calorimeter ranges from 0.72 at 5 GeV to 0.95 at 300 GeV, indicating a substantial nonlinearity. The intrinsic electron to hadron ratios are fit as a function of energy and found to be in the range 1.3-2.7 for the electromagnetic compartment and 1.4-1.8 for the hadronic compartment. The fits are used to correct the non-linearity of the e pi response to 5% over the entire measured range resulting in a substantially improved resolution at low energy. Longitudinal shower profile have been measured in detail and compared to Geant4 models, LHEP-3.7 and QGSP-2.8. At energies below 30 GeV, the data, LHEP and QGSP are...

  18. New networking solutions support GEANT2

    CERN Multimedia

    2006-01-01

    "Researchers across the globe are benefiting from new advanced networking solutions, deployed as part of the GEANT2. For the first time, scientists collaborating on the world's largest particle physics experiment, the Large Hadron Collider (LHC), now have access to point-to-point network connections between distributed research centres." (1 page)

  19. The performance of a new Geant4 Bertini intra-nuclear cascade model in high throughput computing (HTC) cluster architecture

    Energy Technology Data Exchange (ETDEWEB)

    Aatos, Heikkinen; Andi, Hektor; Veikko, Karimaki; Tomas, Linden [Helsinki Univ., Institute of Physics (Finland)

    2003-07-01

    We study the performance of a new Bertini intra-nuclear cascade model implemented in the general detector simulation tool-kit Geant4 with a High Throughput Computing (HTC) cluster architecture. A 60 node Pentium III open-Mosix cluster is used with the Mosix kernel performing automatic process load-balancing across several CPUs. The Mosix cluster consists of several computer classes equipped with Windows NT workstations that automatically boot, daily and become nodes of the Mosix cluster. The models included in our study are a Bertini intra-nuclear cascade model with excitons, consisting of a pre-equilibrium model, a nucleus explosion model, a fission model and an evaporation model. The speed and accuracy obtained for these models is presented. (authors)

  20. The simulation of the LANFOS-H food radiation contamination detector using Geant4 package

    Science.gov (United States)

    Piotrowski, Lech Wiktor; Casolino, Marco; Ebisuzaki, Toshikazu; Higashide, Kazuhiro

    2015-02-01

    Recent incident in the Fukushima power plant caused a growing concern about the radiation contamination and resulted in lowering the Japanese limits for the permitted amount of 137Cs in food to 100 Bq/kg. To increase safety and ease the concern we are developing LANFOS (Large Food Non-destructive Area Sampler)-a compact, easy to use detector for assessment of radiation in food. Described in this paper LANFOS-H has a 4 π coverage to assess the amount of 137Cs present, separating it from the possible 40K food contamination. Therefore, food samples do not have to be pre-processed prior to a test and can be consumed after measurements. It is designed for use by non-professionals in homes and small institutions such as schools, showing safety of the samples, but can be also utilized by specialists providing radiation spectrum. Proper assessment of radiation in food in the apparatus requires estimation of the γ conversion factor of the detectors-how many γ photons will produce a signal. In this paper we show results of the Monte Carlo estimation of this factor for various approximated shapes of fish, vegetables and amounts of rice, performed with Geant4 package. We find that the conversion factor combined from all the detectors is similar for all food types and is around 37%, varying maximally by 5% with sample length, much less than for individual detectors. The different inclinations and positions of samples in the detector introduce uncertainty of 1.4%. This small uncertainty validates the concept of a 4 π non-destructive apparatus.

  1. Modeling Monte Carlo of multileaf collimators using the code GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Alex C.H.; Lima, Fernando R.A., E-mail: oliveira.ach@yahoo.com, E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Lima, Luciano S.; Vieira, Jose W., E-mail: lusoulima@yahoo.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil)

    2014-07-01

    Radiotherapy uses various techniques and equipment for local treatment of cancer. The equipment most often used in radiotherapy to the patient irradiation is linear accelerator (Linac). Among the many algorithms developed for evaluation of dose distributions in radiotherapy planning, the algorithms based on Monte Carlo (MC) methods have proven to be very promising in terms of accuracy by providing more realistic results. The MC simulations for applications in radiotherapy are divided into two parts. In the first, the simulation of the production of the radiation beam by the Linac is performed and then the phase space is generated. The phase space contains information such as energy, position, direction, etc. of millions of particles (photons, electrons, positrons). In the second part the simulation of the transport of particles (sampled phase space) in certain configurations of irradiation field is performed to assess the dose distribution in the patient (or phantom). Accurate modeling of the Linac head is of particular interest in the calculation of dose distributions for intensity modulated radiation therapy (IMRT), where complex intensity distributions are delivered using a multileaf collimator (MLC). The objective of this work is to describe a methodology for modeling MC of MLCs using code Geant4. To exemplify this methodology, the Varian Millennium 120-leaf MLC was modeled, whose physical description is available in BEAMnrc Users Manual (20 11). The dosimetric characteristics (i.e., penumbra, leakage, and tongue-and-groove effect) of this MLC were evaluated. The results agreed with data published in the literature concerning the same MLC. (author)

  2. Simulation of the Production of Secondary Particles from a Neutron Beam on Polyethylene Targets using the GEANT4 Simulation Tool

    CERN Document Server

    Ilgner, C

    2003-01-01

    In view of a beam test of RadFET semiconductor detectors and optically stimulated luminescence (OSL) detectors as on-line dosimeters for radiation monitoring purposes in the caverns of the Large Hadron Collider (LHC) experiments, a simulation on the production of secondary particles from a neutron beam on a polyethylene target was carried out. We describe the yield of recoil protons, scattered neutrons as well as electrons, positrons and photons, when neutrons of an average energy of 20 MeV hit polyethylene targets of several thicknesses. The simulation was carried out using the latest release 5.2 of the GEANT4 detector description and simulation tool, including advanced hadron interaction models.

  3. Simulation of "6"0Co and "1"3"7Csspectra of irradiator Shepherd 81 - 14D do LNMRI/IRD using Geant4

    International Nuclear Information System (INIS)

    Queiroz Filho, P.P.; Cabral, T.S.; Silva, C.N.M. da

    2016-01-01

    In this work it were simulated, using Geant4, the "6"0Co and "1"3"7Cs spectra of the Irradiator Shepherd 81-14D acquired by the National Metrology Laboratory of Ionising Radiation of the Institute of Radiation Protection and Dosimetry ( LNMRI / IRD ), which will be used for calibration in radioprotection. Was checked if photons suffered his first interaction on the source, the structure of the head or the collimators. It was also observed the percentage of occurrence of each type of interaction in such structures. (author)

  4. 32 CFR 516.25 - DA Form 4.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true DA Form 4. 516.25 Section 516.25 National Defense... LITIGATION Reporting Legal Proceedings to HQDA § 516.25 DA Form 4. (a) General. The DA Form 4 (See figure C-2... properly prepared and sealed DA Form 4 are self-authenticating. (See Fed. R. Evid. 902). (b) Preparation at...

  5. Determination of tungsten target parameters for transmission X-ray tube: A simulation study using Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Nasseri, Mohammad M. [School of Plasma Physics and Nuclear Fusion, Institute of Nuclear Science and Technology (AEOI), Tehran (Iran, Islamic Republic of)

    2016-06-15

    Transmission X-ray tubes based on carbon nanotube have attracted significant attention recently. In most of these tubes, tungsten is used as the target material. In this article, the well-known simulator Geant4 was used to obtain some of the tungsten target parameters. The optimal thickness for maximum production of usable X-rays when the target is exposed to electron beams of different energies was obtained. The linear variation of optimal thickness of the target for different electron energies was also obtained. The data obtained in this study can be used to design X-ray tubes. A beryllium window was considered for the X-ray tube. The X-ray energy spectra at the moment of production and after passing through the target and window for different electron energies in the 30-110 keV range were also obtained. The results obtained show that with a specific thickness, the target material itself can act as filter, which enables generation of X-rays with a limited energy.

  6. Design and optimization of an energy degrader with a multi-wedge scheme based on Geant4

    Science.gov (United States)

    Liang, Zhikai; Liu, Kaifeng; Qin, Bin; Chen, Wei; Liu, Xu; Li, Dong; Xiong, Yongqian

    2018-05-01

    A proton therapy facility based on an isochronous superconducting cyclotron is under construction in Huazhong University of Science and Technology (HUST). To meet the clinical requirements, an energy degrader is essential in the beamline to modulate the fixed beam energy extracted from the cyclotron. Because of the multiple Coulomb scattering in the degrader, the beam emittance and the energy spread will be considerably increased during the energy degradation process. Therefore, a set of collimators is designed to restrict the increase in beam emittance after the energy degradation. The energy spread will be reduced in the following beam line which is not discussed in this paper. In this paper, the design considerations of an energy degrader and collimators are introduced, and the properties of the degrader material, degrader structure and the initial beam parameters are discussed using the Geant4 Monte-Carlo toolkit, with the main purpose of improving the overall performance of the degrader by multiple parameter optimization.

  7. Microdosimetry spectra and RBE of 1H, 4He, 7Li and 12C nuclei in water studied with Geant4

    International Nuclear Information System (INIS)

    Burigo, Lucas; Pshenichnov, Igor; Mishustin, Igor; Bleicher, Marcus

    2014-01-01

    A Geant4-based Monte Carlo model for Heavy-Ion Therapy (MCHIT) is used to study radiation fields of 1 H, 4 He, 7 Li and 12 C beams with similar ranges (∼160–180 mm) in water. Microdosimetry spectra are simulated for wall-less and walled Tissue Equivalent Proportional Counters (TEPCs) placed outside or inside a phantom, as in experiments performed, respectively, at NIRS, Japan and GSI, Germany. The impact of fragmentation reactions on microdosimetry spectra is investigated for 4 He, 7 Li and 12 C, and contributions from nuclear fragments of different charge are evaluated for various TEPC positions in the phantom. The microdosimetry spectra measured on the beam axis are well described by MCHIT, in particular, in the vicinity of the Bragg peak. However, the simulated spectra for the walled TEPC far from the beam axis are underestimated. Relative Biological Effectiveness (RBE) of the considered beams is estimated using a modified microdosimetric-kinetic model. Calculations show a similar rise of the RBE up to 2.2–2.9 close to the Bragg peak for helium, lithium and carbon beams compared to the modest values of 1–1.2 at the plateau region. Our results suggest that helium and lithium beams are also promising options for cancer therapy

  8. A computationally efficient moment-preserving Monte Carlo electron transport method with implementation in Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.A., E-mail: ddixon@lanl.gov [Los Alamos National Laboratory, P.O. Box 1663, MS P365, Los Alamos, NM 87545 (United States); Prinja, A.K., E-mail: prinja@unm.edu [Department of Nuclear Engineering, MSC01 1120, 1 University of New Mexico, Albuquerque, NM 87131-0001 (United States); Franke, B.C., E-mail: bcfrank@sandia.gov [Sandia National Laboratories, Albuquerque, NM 87123 (United States)

    2015-09-15

    This paper presents the theoretical development and numerical demonstration of a moment-preserving Monte Carlo electron transport method. Foremost, a full implementation of the moment-preserving (MP) method within the Geant4 particle simulation toolkit is demonstrated. Beyond implementation details, it is shown that the MP method is a viable alternative to the condensed history (CH) method for inclusion in current and future generation transport codes through demonstration of the key features of the method including: systematically controllable accuracy, computational efficiency, mathematical robustness, and versatility. A wide variety of results common to electron transport are presented illustrating the key features of the MP method. In particular, it is possible to achieve accuracy that is statistically indistinguishable from analog Monte Carlo, while remaining up to three orders of magnitude more efficient than analog Monte Carlo simulations. Finally, it is shown that the MP method can be generalized to any applicable analog scattering DCS model by extending previous work on the MP method beyond analytical DCSs to the partial-wave (PW) elastic tabulated DCS data.

  9. Characterisation of a SAGe well detector using GEANT4 and LabSOCS

    Energy Technology Data Exchange (ETDEWEB)

    Britton, R., E-mail: rich.britton@awe.co.uk [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); University of Surrey, Guildford GU2 7XH (United Kingdom); Davies, A.V. [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom)

    2015-06-21

    This paper reports on the performance of a recently developed Small Anode Germanium (SAGe) well detector from Canberra Industries. This has been specifically designed to improve the energy resolution of the detector, such that it is comparable to the performance of broad-energy designs while achieving far higher efficiencies. Accurate efficiency characterisations and cascade summing correction factors are crucial for quantifying the radionuclides present in environmental samples, and these were calculated for the complex geometry posed by the well detector using two different methodologies. The first relied on Monte-Carlo simulations based upon the GEANT4 toolkit, and the second utilised Canberra Industries GENIE™ 2000 Gamma Analysis software in conjunction with a LabSOCS™ characterisation. Both were found to be in excellent agreement for all nuclides except for {sup 152}Eu, which presents a known issue in the Canberra software (all nuclides affected by this issue were well documented, and fixes are being developed). The correction factors were used to analyse two fully characterised reference samples, yielding results in good agreement with the accepted activity concentrations. Given the sensitivity of well type geometries to cascade summing, this represents a considerable achievement, and paves the way for the use of the SAGe well detector in analysis of ‘real-world’ environmental samples. With the efficiency increase when using the SAGe well in place of a BEGe, substantial reductions in the Minimum Detectable Activity (MDA) should be achievable for a range of nuclides.

  10. Characterisation of a SAGe well detector using GEANT4 and LabSOCS

    International Nuclear Information System (INIS)

    Britton, R.; Davies, A.V.

    2015-01-01

    This paper reports on the performance of a recently developed Small Anode Germanium (SAGe) well detector from Canberra Industries. This has been specifically designed to improve the energy resolution of the detector, such that it is comparable to the performance of broad-energy designs while achieving far higher efficiencies. Accurate efficiency characterisations and cascade summing correction factors are crucial for quantifying the radionuclides present in environmental samples, and these were calculated for the complex geometry posed by the well detector using two different methodologies. The first relied on Monte-Carlo simulations based upon the GEANT4 toolkit, and the second utilised Canberra Industries GENIE™ 2000 Gamma Analysis software in conjunction with a LabSOCS™ characterisation. Both were found to be in excellent agreement for all nuclides except for 152 Eu, which presents a known issue in the Canberra software (all nuclides affected by this issue were well documented, and fixes are being developed). The correction factors were used to analyse two fully characterised reference samples, yielding results in good agreement with the accepted activity concentrations. Given the sensitivity of well type geometries to cascade summing, this represents a considerable achievement, and paves the way for the use of the SAGe well detector in analysis of ‘real-world’ environmental samples. With the efficiency increase when using the SAGe well in place of a BEGe, substantial reductions in the Minimum Detectable Activity (MDA) should be achievable for a range of nuclides

  11. Compressive effect of the magnetic field on the positron range in commonly used positron emitters simulated using Geant4

    Science.gov (United States)

    Li, Chong; Cao, Xingzhong; Liu, Fuyan; Tang, Haohui; Zhang, Zhiming; Wang, Baoyi; Wei, Long

    2017-11-01

    The compressive effect of a magnetic field on the positron range from commonly used positron emitters in PET (Positron Emission Tomography) was simulated using the Geant4 toolkit with H2O as the environmental material. The compression of the positron range, which was different in the directions parallel and perpendicular to the magnetic field, showed finite final variation of relative change rate versus the magnetic field. The variation greatly depended on the positron-emission energy spectrum in the same medium. Furthermore, the volume of the positron annihilation point was dramatically compressed as the magnetic field was set in the range of 3-6T. It was more prominent for 82Rb , which is generally used as a positron source in PET technology.

  12. Calibration and GEANT4 Simulations of the Phase II Proton Compute Tomography (pCT) Range Stack Detector

    Energy Technology Data Exchange (ETDEWEB)

    Uzunyan, S. A. [Northern Illinois Univ., DeKalb, IL (United States); Blazey, G. [Northern Illinois Univ., DeKalb, IL (United States); Boi, S. [Northern Illinois Univ., DeKalb, IL (United States); Coutrakon, G. [Northern Illinois Univ., DeKalb, IL (United States); Dyshkant, A. [Northern Illinois Univ., DeKalb, IL (United States); Francis, K. [Northern Illinois Univ., DeKalb, IL (United States); Hedin, D. [Northern Illinois Univ., DeKalb, IL (United States); Johnson, E. [Northern Illinois Univ., DeKalb, IL (United States); Kalnins, J. [Northern Illinois Univ., DeKalb, IL (United States); Zutshi, V. [Northern Illinois Univ., DeKalb, IL (United States); Ford, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rauch, J. E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rubinov, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Sellberg, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wilson, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Naimuddin, M. [Univ. of Delhi, New Delhi (India)

    2015-12-29

    Northern Illinois University in collaboration with Fermi National Accelerator Laboratory (FNAL) and Delhi University has been designing and building a proton CT scanner for applications in proton treatment planning. The Phase II proton CT scanner consists of eight planes of tracking detectors with two X and two Y coordinate measurements both before and after the patient. In addition, a range stack detector consisting of a stack of thin scintillator tiles, arranged in twelve eight-tile frames, is used to determine the water equivalent path length (WEPL) of each track through the patient. The X-Y coordinates and WEPL are required input for image reconstruction software to find the relative (proton) stopping powers (RSP) value of each voxel in the patient and generate a corresponding 3D image. In this Note we describe tests conducted in 2015 at the proton beam at the Central DuPage Hospital in Warrenville, IL, focusing on the range stack calibration procedure and comparisons with the GEANT~4 range stack simulation.

  13. GEANT4 simulation and evaluation of a time-of-flight spectrometer for nuclear cross section measurements in particle therapy

    International Nuclear Information System (INIS)

    Gruenwald, Oxana

    2011-01-01

    In 2007 a new project has been launched in a cooperation between the RWTH Aachen Physics Department, the University Hospital Aachen and the Philips Research Laboratories. The project aim is to validate and improve GEANT4 nuclear interaction models for use in proton and ion therapy. The method chosen here is the measurement of nuclear reaction cross sections which will not only provide a comparison to the simulation but will also allow to improve some of the parameters in the nuclear models. In the first phase of the project 200 MeV protons are used as a projectile in combination with a thin graphite target. For use in particle therapy the excitation functions of the most frequently produced isotopes need to be measured with an accuracy of 10% or less. For this purpose a dedicated detector system has been designed and implemented in GEANT4. The detection of target fragments produced by protons in graphite is achieved via time-of-flight spectrometry. In the setup presented here the primary beam first hits the Start detector and initiates the time-of-flight measurement before it passes through the apertures of two Veto detectors and impinges on the target. Successively, the secondary particles emanating from the target travel a short distance of 70/80 cm through vacuum (0.1 mbar) before they hit one of the 20 Stop detectors which end the time-of-flight measurement and record the energy deposited by the particle. The dissertation at hand describes the underlying detector concept and presents a detailed GEANT4 simulation of the setup which allows to evaluate the detector performance with respect to target fragment identification at a projectile energy of 200 MeV. At first, correlations of time-of-flight and energy deposition are built from simulated data and are subsequently used to reconstruct mass spectra of the detected fragments. Such influences on the detection performance as the target thickness, the residual pressure within the detector chamber, the Veto system

  14. GEANT4 simulation and evaluation of a time-of-flight spectrometer for nuclear cross section measurements in particle therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gruenwald, Oxana

    2011-06-08

    In 2007 a new project has been launched in a cooperation between the RWTH Aachen Physics Department, the University Hospital Aachen and the Philips Research Laboratories. The project aim is to validate and improve GEANT4 nuclear interaction models for use in proton and ion therapy. The method chosen here is the measurement of nuclear reaction cross sections which will not only provide a comparison to the simulation but will also allow to improve some of the parameters in the nuclear models. In the first phase of the project 200 MeV protons are used as a projectile in combination with a thin graphite target. For use in particle therapy the excitation functions of the most frequently produced isotopes need to be measured with an accuracy of 10% or less. For this purpose a dedicated detector system has been designed and implemented in GEANT4. The detection of target fragments produced by protons in graphite is achieved via time-of-flight spectrometry. In the setup presented here the primary beam first hits the Start detector and initiates the time-of-flight measurement before it passes through the apertures of two Veto detectors and impinges on the target. Successively, the secondary particles emanating from the target travel a short distance of 70/80 cm through vacuum (0.1 mbar) before they hit one of the 20 Stop detectors which end the time-of-flight measurement and record the energy deposited by the particle. The dissertation at hand describes the underlying detector concept and presents a detailed GEANT4 simulation of the setup which allows to evaluate the detector performance with respect to target fragment identification at a projectile energy of 200 MeV. At first, correlations of time-of-flight and energy deposition are built from simulated data and are subsequently used to reconstruct mass spectra of the detected fragments. Such influences on the detection performance as the target thickness, the residual pressure within the detector chamber, the Veto system

  15. BC404 scintillators as gamma locators studied via Geant4 simulations

    Science.gov (United States)

    Cortés, M. L.; Hoischen, R.; Eisenhauer, K.; Gerl, J.; Pietralla, N.

    2014-05-01

    In many applications in industry and academia, an accurate determination of the direction from where gamma rays are emitted is either needed or desirable. Ion-beam therapy treatments, the search for orphan sources, and homeland security applications are examples of fields that can benefit from directional sensitivity to gamma-radiation. Scintillation detectors are a good option for these types of applications as they have relatively low cost, are easy to handle and can be produced in a large range of different sizes. In this work a Geant4 simulation was developed to study the directional sensitivity of different BC404 scintillator geometries and arrangements. The simulation includes all the physical processes relevant for gamma detection in a scintillator. In particular, the creation and propagation of optical photons inside the scintillator was included. A simplified photomultiplier tube model was also simulated. The physical principle exploited is the angular dependence of the shape of the energy spectrum obtained from thin scintillator layers when irradiated from different angles. After an experimental confirmation of the working principle of the device and a check of the simulation, the possibilities and limitations of directional sensitivity to gamma radiation using scintillator layers was tested. For this purpose, point-like sources of typical energies expected in ion-beam therapy were used. Optimal scintillator thicknesses for different energies were determined and the setup efficiencies calculated. The use of arrays of scintillators to reconstruct the direction of incoming gamma rays was also studied. For this case, a spherical source emitting Bremsstrahlung radiation was used together with a setup consisting of scintillator layers. The capability of this setup to identify the center of the extended source was studied together with its angular resolution.

  16. Geant4 Analysis of a Thermal Neutron Real-Time Imaging System

    Science.gov (United States)

    Datta, Arka; Hawari, Ayman I.

    2017-07-01

    Thermal neutron imaging is a technique for nondestructive testing providing complementary information to X-ray imaging for a wide range of applications in science and engineering. Advancement of electronic imaging systems makes it possible to obtain neutron radiographs in real time. This method requires a scintillator to convert neutrons to optical photons and a charge-coupled device (CCD) camera to detect those photons. Alongside, a well collimated beam which reduces geometrical blurriness, the use of a thin scintillator can improve the spatial resolution significantly. A representative scintillator that has been applied widely for thermal neutron imaging is 6LiF:ZnS (Ag). In this paper, a multiphysics simulation approach for designing thermal neutron imaging system is investigated. The Geant4 code is used to investigate the performance of a thermal neutron imaging system starting with a neutron source and including the production of charged particles and optical photons in the scintillator and their transport for image formation in the detector. The simulation geometry includes the neutron beam collimator and sapphire filter. The 6LiF:ZnS (Ag) scintillator is modeled along with a pixelated detector for image recording. The spatial resolution of the system was obtained as the thickness of the scintillator screen was varied between 50 and 400 μm. The results of the simulation were compared to experimental results, including measurements performed using the PULSTAR nuclear reactor imaging beam, showing good agreement. Using the established model, further examination showed that the resolution contribution of the scintillator screen is correlated with its thickness and the range of the neutron absorption reaction products (i.e., the alpha and triton particles). Consequently, thinner screens exhibit improved spatial resolution. However, this will compromise detection efficiency due to the reduced probability of neutron absorption.

  17. Geant4 Monte Carlo simulation of absorbed dose and radiolysis yields enhancement from a gold nanoparticle under MeV proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tran, H.N., E-mail: tranngochoang@tdt.edu.vn [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Karamitros, M. [Notre Dame Radiation Laboratory, University of Notre-Dame, IN 46556 (United States); Ivanchenko, V.N. [Geant4 Associates International Ltd, Hebden Bridge (United Kingdom); Guatelli, S.; McKinnon, S. [Centre For Medical Radiation Physics, University of Wollongong (Australia); Illawarra Health and Medical Research, University of Wollongong, NSW (Australia); Murakami, K.; Sasaki, T.; Okada, S. [Computing Research Center, High Energy Accelerator Organization, KEK, Tsukuba City (Japan); Bordage, M.C. [INSERM, UMR 1037, CRCT, F-31000 Toulouse (France); Univ. Toulouse III-Paul Sabatier, UMR 1037, CRCT, F-31000 Toulouse (France); Francis, Z. [Saint Joseph University, Faculty of Sciences, Department of Physics, Beirut (Lebanon); El Bitar, Z. [Institut Pluridisciplinaire Hubert Curien/IN2P3/CNRS, Strasbourg (France); Bernal, M.A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, SP (Brazil); Shin, J.I. [Division of Heavy Ion Clinical Research, Korea Institute of Radiological and Medical Science, 75, Nowon-ro, Nowon-gu, Seoul (Korea, Republic of); Lee, S.B. [Proton Therapy Center, National Cancer Center, 323, Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do (Korea, Republic of); Barberet, Ph. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Tran, T.T. [VNUHCM-University of Science (Viet Nam); Brown, J.M.C. [School of Mathematics and Physics, Queen’s University Belfast, Belfast, Northern Ireland (United Kingdom); and others

    2016-04-15

    Gold nanoparticles have been reported as a possible radio-sensitizer agent in radiation therapy due to their ability to increase energy deposition and subsequent direct damage to cells and DNA within their local vicinity. Moreover, this increase in energy deposition also results in an increase of the radiochemical yields. In this work we present, for the first time, an in silico investigation, based on the general purpose Monte Carlo simulation toolkit Geant4, into energy deposition and radical species production around a spherical gold nanoparticle 50 nm in diameter via proton irradiation. Simulations were preformed for incident proton energies ranging from 2 to 170 MeV, which are of interest for clinical proton therapy.

  18. A Mitologia na Representação cultural e no consumo :Efeito e recepção do signo da cachaça

    OpenAIRE

    SILVA, Daniella Ramos da

    2009-01-01

    Este trabalho relata o estudo da mitologia na representação cultural e no consumo da cachaça. A origem pobre da cachaça determinou a inerência de mitos de desqualificação em sua representação cultural, tornando-a estigmatizada. Tendo em vista que o consumo não é mais tido como uma simples compra de produtos (bens ou serviços), mas de significados, a representação influencia o consumo, assim como o consumo influencia a representação. Com base neste pressuposto, procurou-se enten...

  19. Linking computer-aided design (CAD) to Geant4-based Monte Carlo simulations for precise implementation of complex treatment head geometries

    International Nuclear Information System (INIS)

    Constantin, Magdalena; Constantin, Dragos E; Keall, Paul J; Narula, Anisha; Svatos, Michelle; Perl, Joseph

    2010-01-01

    Most of the treatment head components of medical linear accelerators used in radiation therapy have complex geometrical shapes. They are typically designed using computer-aided design (CAD) applications. In Monte Carlo simulations of radiotherapy beam transport through the treatment head components, the relevant beam-generating and beam-modifying devices are inserted in the simulation toolkit using geometrical approximations of these components. Depending on their complexity, such approximations may introduce errors that can be propagated throughout the simulation. This drawback can be minimized by exporting a more precise geometry of the linac components from CAD and importing it into the Monte Carlo simulation environment. We present a technique that links three-dimensional CAD drawings of the treatment head components to Geant4 Monte Carlo simulations of dose deposition. (note)

  20. The radiation environment on the surface of Mars - Numerical calculations of the galactic component with GEANT4/PLANETOCOSMICS.

    Science.gov (United States)

    Matthiä, Daniel; Berger, Thomas

    2017-08-01

    Galactic cosmic radiation and secondary particles produced in the interaction with the atmosphere lead to a complex radiation field on the Martian surface. A workshop ("1st Mars Space Radiation Modeling Workshop") organized by the MSL-RAD science team was held in June 2016 in Boulder with the goal to compare models capable to predict this radiation field with each other and measurements from the RAD instrument onboard the curiosity rover taken between November 15, 2015 and January 15, 2016. In this work the results of PLANETOCOSMICS/GEANT4 contributed to the workshop are presented. Calculated secondary particle spectra on the Martian surface are investigated and the radiation field's directionality of the different particles in dependence on the energy is discussed. Omnidirectional particle fluxes are used in combination with fluence to dose conversion factors to calculate absorbed dose rates and dose equivalent rates in a slab of tissue. Copyright © 2017. Published by Elsevier Ltd.

  1. Geant4 simulation of the Elekta XVI kV CBCT unit for accurate description of potential late toxicity effects of image-guided radiotherapy

    International Nuclear Information System (INIS)

    Brochu, F M; Burnet, N G; Jena, R; Plaistow, R; Thomas, S J; Parker, M A

    2014-01-01

    This paper describes the modelisation of the Elekta XVI Cone Beam Computed Tomography (CBCT) machine components with Geant4 and its validation against calibration data taken for two commonly used machine setups. Preliminary dose maps of simulated CBCTs coming from this modelisation work are presented. This study is the first step of a research project, GHOST, aiming to improve the understanding of late toxicity risk in external beam radiotherapy patients by simulating dose depositions integrated from different sources (imaging, treatment beam) over the entire treatment plan. The second cancer risk will then be derived from different models relating irradiation dose and second cancer risk. (paper)

  2. Consistency evaluation between EGSnrc and Geant4 charged particle transport in an equilibrium magnetic field.

    Science.gov (United States)

    Yang, Y M; Bednarz, B

    2013-02-21

    Following the proposal by several groups to integrate magnetic resonance imaging (MRI) with radiation therapy, much attention has been afforded to examining the impact of strong (on the order of a Tesla) transverse magnetic fields on photon dose distributions. The effect of the magnetic field on dose distributions must be considered in order to take full advantage of the benefits of real-time intra-fraction imaging. In this investigation, we compared the handling of particle transport in magnetic fields between two Monte Carlo codes, EGSnrc and Geant4, to analyze various aspects of their electromagnetic transport algorithms; both codes are well-benchmarked for medical physics applications in the absence of magnetic fields. A water-air-water slab phantom and a water-lung-water slab phantom were used to highlight dose perturbations near high- and low-density interfaces. We have implemented a method of calculating the Lorentz force in EGSnrc based on theoretical models in literature, and show very good consistency between the two Monte Carlo codes. This investigation further demonstrates the importance of accurate dosimetry for MRI-guided radiation therapy (MRIgRT), and facilitates the integration of a ViewRay MRIgRT system in the University of Wisconsin-Madison's Radiation Oncology Department.

  3. Consistency evaluation between EGSnrc and Geant4 charged particle transport in an equilibrium magnetic field

    International Nuclear Information System (INIS)

    Yang, Y M; Bednarz, B

    2013-01-01

    Following the proposal by several groups to integrate magnetic resonance imaging (MRI) with radiation therapy, much attention has been afforded to examining the impact of strong (on the order of a Tesla) transverse magnetic fields on photon dose distributions. The effect of the magnetic field on dose distributions must be considered in order to take full advantage of the benefits of real-time intra-fraction imaging. In this investigation, we compared the handling of particle transport in magnetic fields between two Monte Carlo codes, EGSnrc and Geant4, to analyze various aspects of their electromagnetic transport algorithms; both codes are well-benchmarked for medical physics applications in the absence of magnetic fields. A water–air–water slab phantom and a water–lung–water slab phantom were used to highlight dose perturbations near high- and low-density interfaces. We have implemented a method of calculating the Lorentz force in EGSnrc based on theoretical models in literature, and show very good consistency between the two Monte Carlo codes. This investigation further demonstrates the importance of accurate dosimetry for MRI-guided radiation therapy (MRIgRT), and facilitates the integration of a ViewRay MRIgRT system in the University of Wisconsin-Madison's Radiation Oncology Department. (note)

  4. Thick-foils activation technique for neutron spectrum unfolding with the MINUIT routine-Comparison with GEANT4 simulations

    Science.gov (United States)

    Vagena, E.; Theodorou, K.; Stoulos, S.

    2018-04-01

    Neutron activation technique has been applied using a proposed set of twelve thick metal foils (Au, As, Cd, In, Ir, Er, Mn, Ni, Se, Sm, W, Zn) for off-site measurements to obtain the neutron spectrum over a wide energy range (from thermal up to a few MeV) in intense neutron-gamma mixed fields such as around medical Linacs. The unfolding procedure takes into account the activation rates measured using thirteen (n , γ) and two (n , p) reactions without imposing a guess solution-spectrum. The MINUIT minimization routine unfolds a neutron spectrum that is dominated by fast neutrons (70%) peaking at 0.3 MeV, while the thermal peak corresponds to the 15% of the total neutron fluence equal to the epithermal-resonances area. The comparison of the unfolded neutron spectrum against the simulated one with the GEANT4 Monte-Carlo code shows a reasonable agreement within the measurement uncertainties. Therefore, the proposed set of activation thick-foils could be a useful tool in order to determine low flux neutrons spectrum in intense mixed field.

  5. GEANT Monte Carlo simulations for the GREAT spectrometer

    International Nuclear Information System (INIS)

    Andreyev, A.N.; Butler, P.A.; Page, R.D.; Appelbe, D.E.; Jones, G.D.; Joss, D.T.; Herzberg, R.-D.; Regan, P.H.; Simpson, J.; Wadsworth, R.

    2004-01-01

    GEANT Monte Carlo simulations for the recently developed GREAT spectrometer are presented. Some novel applications of the spectrometer for γ-ray, conversion-electron and β-decay spectroscopy are discussed. The conversion-electron spectroscopy of heavy nuclei with strongly converted transitions and the extension of the recoil decay tagging method to β-decaying nuclei are considered in detail

  6. INFLUÊNCIA DA MATÉRIA ORGÂNICA NA BIODEGRADAÇÃO DO ÁCIDO 2,4-DICLOROFENOXIACÉTICO (2,4-D

    Directory of Open Access Journals (Sweden)

    Ida Carolina Neves Direito

    2015-07-01

    Full Text Available O herbicida ácido 2,4-diclorofenoxiacético (2,4-D é um dos mais utilizados no mundo e pode causar prejuízos ao meio ambiente e à saúde humana. Os microrganismos do solo tem importante função na degradação de compostos químicos como os pesticidas. A matéria orgânica, como adubos orgânicos e metabólitos secundários vegetais, podem estimular os microrganismos do solo. Dentre os metabólitos secundários vegetais, existem os flavonóides. O processo de degradação de flavonóides pode resultar no ácido protocatecóico, o qual é um intermediário na rota de degradação de pesticidas aromáticos, como o 2,4-D.  Este estudo investigou a influência da matéria orgânica na biodegradação do 2,4-D. Em um primeiro momento, analizamos a capacidade de crescimento de isolados bacterianos, que podem utilizar 2,4-D como única fonte de carbono, na presença de biopirol, quercetina e rutina. Em seguida, verificamos a influência destas moléculas orgânicas sobre a comunidade microbiana do solo com histórico de aplicação do 2,4-D. Os resultados mostraram que os isolados bacterianos são capazes de utilizar pelo menos um dos modelos de matéria orgânica empregados. Os resultados gerados no experimento conduzido para verificar a influencia da matéria orgânica sobre a comunidade microbiana e a degradação do 2,4-D sugere que a associação do 2,4-D com a matéria orgânica poderia ampliar a persistência deste no ambiente, ou poderia representar um estádio de adaptação dos microrganismos do solo. Nossos resultados sugerem que o efeito de resíduos orgânicos na biodegradação do 2,4-D tem potencial biotecnológico.

  7. GEANT4 simulation diagram showing the architecture of the ATLAS test line: the detectors are positioned to receive the beam from the SPS. A muon particle which enters the magnet and crosses all detectors is shown (blue line).

    CERN Multimedia

    2004-01-01

    GEANT4 simulation diagram showing the architecture of the ATLAS test line: the detectors are positioned to receive the beam from the SPS. A muon particle which enters the magnet and crosses all detectors is shown (blue line).

  8. GEANT4-based full simulation of the PADME experiment at the DAΦNE BTF

    Science.gov (United States)

    Leonardi, E.; Kozhuharov, V.; Raggi, M.; Valente, P.

    2017-10-01

    A possible solution to the dark matter problem postulates that dark particles can interact with Standard Model particles only through a new force mediated by a “portal”. If the new force has a U(1) gauge structure, the “portal” is a massive photon-like vector particle, called dark photon or A‧. The PADME experiment at the DAΦNE Beam-Test Facility (BTF) in Frascati is designed to detect dark photons produced in positron on fixed target annihilations decaying to dark matter (e+e-→γA‧) by measuring the final state missing mass. The experiment will be composed of a thin active diamond target where a 550 MeV positron beam will impinge to produce e+e- annihilation events. The surviving beam will be deflected with a magnet while the photons produced in the annihilation will be measured by a calorimeter composed of BGO crystals. To reject the background from Bremsstrahlung gamma production, a set of segmented plastic scintillator vetoes will be used to detect positrons exiting the target with an energy lower than that of the beam, while a fast small angle calorimeter will be used to reject the e+e-→γγ(γ) background. To optimize the experimental layout in terms of signal acceptance and background rejection, the full layout of the experiment was modelled with the GEANT4 simulation package. In this paper we will describe the details of the simulation and report on the results obtained with the software.

  9. The implementation of quality controls of gamma camera functioning and simulation of tomography techniques by Gate and GEANT4

    International Nuclear Information System (INIS)

    Ben Ameur, Narjes

    2011-01-01

    The reliability of medical devices is directly linked to the services quality offered to the patient. For this reason, quality control tests should be regularly conducted in every nuclear medicine service according to international norms. Our approach consists on realizing different quality control tests recommended by the Nema norm on a gamma-camera in order to evaluate its performance. The obtained data allowed us to study the different physical phenomena happening during a SPECT exam. It also allowed us to identify those affecting the image quality based on the simulation programmes: GEANT 4 and Gate. The obtained results of the quality control showed that the Gamma-camera has a high performance in terms of spatial resolution, linearity, uniformity and rotational center. The establishment of a model for a gamma-camera Symbia E (Siemens) using a Gate platform confirms the reliability of this platform in the conception and the optimization of the detectors.

  10. Influencia do indice de massa corporal no equilibrio e na configuracao plantar em obesos adultos

    Directory of Open Access Journals (Sweden)

    Liu Chiao Yi

    2014-01-01

    Full Text Available INTRODUÇÃO: A obesidade é uma doença crônica degenerativa multifatorial que pode levar a alterações do sistema musculoesquelético, como mudança do centro de gravidade e sobrecarga mecânica sobre os membros inferiores. OBJETIVOS: Correlacionar o índice de massa corporal (IMC com o equilíbrio corporal e verificar associação entre o IMC e a configuração plantar. MÉTODOS: Foram avaliados 30 obesos, de ambos os gêneros, com IMC maior ou igual a 30 Kg/m². Inicialmente, os voluntários foram submetidos às avaliações de medidas antropométricas a fim de calcular o valor do IMC. Em seguida, foram submetidos ao teste de equilíbrio corporal estático Balance Error Scoring System (BESS e a plantigrafia para a identificação da impressão plantar. Por meio do método de Viladot, os voluntários foram classificados em grupos: pé plano (GPP, pé cavo (GPC e pé neutro (GPN. A correlação entre as variáveis IMC e BESS foi calculada por meio do coeficiente de correlação linear de Pearson e associação entre o IMC e a configuração plantar foi realizada por meio da análise de variância (Anova. Para todas as análises, nível de significância considerado foi p < 0,05. RESULTADOS: Os valores da correlação entre o IMC e o BESS foram r = - 0,1 e p = 0,59. Os valores da associação do IMC entre GPN - GPP; GPN - GPC; GPP - GPC foram respectivamente: p = 0,76; p = 0,001; p = 0,07. CONCLUSÃO: O índice de massa corporal de adultos obesos não influencia o equilíbrio corporal, porém influencia na configuração plantar.

  11. Benefícios da aplicação de azoto, potássio e boro na fisiologia da oliveira em condições de sequeiro

    OpenAIRE

    Bacelar, E.A.; Correia, C.M.; Moutinho-Pereira, J.M.; Gonçalves, Berta; Arrobas, Margarida; Pavão, Francisco; Lopes, João; Cabanas, J.E.; Rodrigues, M.A.

    2007-01-01

    O azoto, o potássio e o boro são nutrientes que frequentemente condicionam a fisiologia da oliveira (Olea europaea L.). O azoto apresenta um papel primordial por ser constituinte de vários compostos orgânicos, em especial proteínas, ácidos nucleicos, hormonas e clorofila. O boro influencia directamente a produção por proporcionar maior desenvolvimento radicular, maximizando o aproveitamento da água e dos fertilizantes, bem como por estar directamente envolvido na formação da parede celular, c...

  12. Optimization of a general-purpose, actively scanned proton beamline for ocular treatments: Geant4 simulations.

    Science.gov (United States)

    Piersimoni, Pierluigi; Rimoldi, Adele; Riccardi, Cristina; Pirola, Michele; Molinelli, Silvia; Ciocca, Mario

    2015-03-08

    The Italian National Center for Hadrontherapy (CNAO, Centro Nazionale di Adroterapia Oncologica), a synchrotron-based hospital facility, started the treatment of patients within selected clinical trials in late 2011 and 2012 with actively scanned proton and carbon ion beams, respectively. The activation of a new clinical protocol for the irradiation of uveal melanoma using the existing general-purpose proton beamline is foreseen for late 2014. Beam characteristics and patient treatment setup need to be tuned to meet the specific requirements for such a type of treatment technique. The aim of this study is to optimize the CNAO transport beamline by adding passive components and minimizing air gap to achieve the optimal conditions for ocular tumor irradiation. The CNAO setup with the active and passive components along the transport beamline, as well as a human eye-modeled detector also including a realistic target volume, were simulated using the Monte Carlo Geant4 toolkit. The strong reduction of the air gap between the nozzle and patient skin, as well as the insertion of a range shifter plus a patient-specific brass collimator at a short distance from the eye, were found to be effective tools to be implemented. In perspective, this simulation toolkit could also be used as a benchmark for future developments and testing purposes on commercial treatment planning systems.

  13. Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Mahdipour, Seyed Ali [Physics Department, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); Mowlavi, Ali Asghar, E-mail: amowlavi@hsu.ac.ir [Physics Department, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); ICTP, Associate Federation Scheme, Medical Physics Field, Trieste (Italy)

    2016-07-01

    Radiotherapy with ion beams like proton and carbon has been used for treatment of eye uveal melanoma for many years. In this research, we have developed a new phantom of human eye for Monte Carlo simulation of tumors treatment to use in GEANT4 toolkit. Total depth−dose profiles for the proton, alpha, and carbon incident beams with the same ranges have been calculated in the phantom. Moreover, the deposited energy of the secondary particles for each of the primary beams is calculated. The dose curves are compared for 47.8 MeV proton, 190.1 MeV alpha, and 1060 MeV carbon ions that have the same range in the target region reaching to the center of tumor. The passively scattered spread-out Bragg peak (SOBP) for each incident beam as well as the flux curves of the secondary particles including neutron, gamma, and positron has been calculated and compared for the primary beams. The high sharpness of carbon beam's Bragg peak with low lateral broadening is the benefit of this beam in hadrontherapy but it has disadvantages of dose leakage in the tail after its Bragg peak and high intensity of neutron production. However, proton beam, which has a good conformation with tumor shape owing to the beam broadening caused by scattering, can be a good choice for the large-size tumors.

  14. Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit

    International Nuclear Information System (INIS)

    Mahdipour, Seyed Ali; Mowlavi, Ali Asghar

    2016-01-01

    Radiotherapy with ion beams like proton and carbon has been used for treatment of eye uveal melanoma for many years. In this research, we have developed a new phantom of human eye for Monte Carlo simulation of tumors treatment to use in GEANT4 toolkit. Total depth−dose profiles for the proton, alpha, and carbon incident beams with the same ranges have been calculated in the phantom. Moreover, the deposited energy of the secondary particles for each of the primary beams is calculated. The dose curves are compared for 47.8 MeV proton, 190.1 MeV alpha, and 1060 MeV carbon ions that have the same range in the target region reaching to the center of tumor. The passively scattered spread-out Bragg peak (SOBP) for each incident beam as well as the flux curves of the secondary particles including neutron, gamma, and positron has been calculated and compared for the primary beams. The high sharpness of carbon beam's Bragg peak with low lateral broadening is the benefit of this beam in hadrontherapy but it has disadvantages of dose leakage in the tail after its Bragg peak and high intensity of neutron production. However, proton beam, which has a good conformation with tumor shape owing to the beam broadening caused by scattering, can be a good choice for the large-size tumors.

  15. Optimization of {sup 6}LiF:ZnS(Ag) Scintillator Light Yield Using Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Yehuda-Zada, Y. [Nuclear Research Center Negev, Beer-Sheva (Israel); Ben-Gurion University (Israel); Pritchard, K.; Ziegler, J.B.; Cooksey, C.; Siebein, K. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Jackson, M.; Hurlbut, C. [Eljen Technology, Sweetwater Texas (United States); Kadmon, Y.; Cohen, Y.; Maliszewskyj, N.C. [Nuclear Research Center Negev, Beer-Sheva (Israel); Ibberson, R.M.; Majkrzak, C.F. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Orion, Y. [Ben-Gurion University (Israel); Osovizky, A. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Rotem Industries Ltd, Rotem Industrial Park (Israel); University of Maryland (United States)

    2015-07-01

    Neutrons provide an effective tool to probe materials structure. Neutron diffraction is a method to determine the atomic and magnetic structure of a material based on neutron scattering. By this method a collimated incident beam of thermal neutrons heat the examined sample and based on the obtained diffraction pattern information on the structure of the material is provided. Research for developing a novel cold neutron detector for Chromatic Analysis Neutron Diffractometer Or Reflectometer (CANDOR) is underway at the NIST center for neutron research. The system unique design is aimed to provide over ten times fold faster analysis of materials than conventional system. In order to achieve the fast analysis a large number of neutron detectors is required. A key design constraint for this detector is the thickness of the neutron sensitive element. This is met using {sup 6}LiF:ZnS(Ag) scintillation material with embedded wavelength shifting (WLS) fibers conducting scintillation light to silicon photomultiplier photo-sensors. The detector sensitivity is determined by both the neutron capture probability ({sup 6}Li density) and the detectable light output produced by the ZnS(Ag) ionization, the latter of which is hindered by the fluorescence absorption of the scintillation light by the ZnS. Tradeoffs between the neutron capture probability, stimulated light production and light attenuation for determining the optimal stoichiometry of the {sup 6}LiF and ZnS(Ag) as well as the volume ratio of scintillator and fiber. Simulations performed using the GEANT4 Monte Carlo package were made in order to optimize the detector design. GEANT4 enables the investigation of the neutron interaction with the detector, the ionization process and the light transfer process following the nuclear process. The series of conversions required for this detector were modelled: - A cold neutron enters the sensor and is captured by {sup 6}Li in the scintillator mixture ({sup 6}Li (n,α) {sup 3}H

  16. Comparison of electron dose-point kernels in water generated by the Monte Carlo codes, PENELOPE, GEANT4, MCNPX, and ETRAN.

    Science.gov (United States)

    Uusijärvi, Helena; Chouin, Nicolas; Bernhardt, Peter; Ferrer, Ludovic; Bardiès, Manuel; Forssell-Aronsson, Eva

    2009-08-01

    Point kernels describe the energy deposited at a certain distance from an isotropic point source and are useful for nuclear medicine dosimetry. They can be used for absorbed-dose calculations for sources of various shapes and are also a useful tool when comparing different Monte Carlo (MC) codes. The aim of this study was to compare point kernels calculated by using the mixed MC code, PENELOPE (v. 2006), with point kernels calculated by using the condensed-history MC codes, ETRAN, GEANT4 (v. 8.2), and MCNPX (v. 2.5.0). Point kernels for electrons with initial energies of 10, 100, 500, and 1 MeV were simulated with PENELOPE. Spherical shells were placed around an isotropic point source at distances from 0 to 1.2 times the continuous-slowing-down-approximation range (R(CSDA)). Detailed (event-by-event) simulations were performed for electrons with initial energies of less than 1 MeV. For 1-MeV electrons, multiple scattering was included for energy losses less than 10 keV. Energy losses greater than 10 keV were simulated in a detailed way. The point kernels generated were used to calculate cellular S-values for monoenergetic electron sources. The point kernels obtained by using PENELOPE and ETRAN were also used to calculate cellular S-values for the high-energy beta-emitter, 90Y, the medium-energy beta-emitter, 177Lu, and the low-energy electron emitter, 103mRh. These S-values were also compared with the Medical Internal Radiation Dose (MIRD) cellular S-values. The greatest differences between the point kernels (mean difference calculated for distances, electrons was 1.4%, 2.5%, and 6.9% for ETRAN, GEANT4, and MCNPX, respectively, compared to PENELOPE, if omitting the S-values when the activity was distributed on the cell surface for 10-keV electrons. The largest difference between the cellular S-values for the radionuclides, between PENELOPE and ETRAN, was seen for 177Lu (1.2%). There were large differences between the MIRD cellular S-values and those obtained from

  17. Aplicação do método Fuzzy na classificação da zona de convergência do Atlântico Sul no sul da Amazônia

    Directory of Open Access Journals (Sweden)

    Samuel Oliveira Vieira

    2014-12-01

    Full Text Available A Zona de Convergência do Atlântico Sul (ZCAS influencia a variabilidade da precipitação no sul da bacia Amazônica. Nesse sentido, foi aplicado o Método da Lógica Fuzzy de modo a ter um mecanismo de alerta para as chuvas acima da média climatológica devido à ZCAS (classificada como oceânica, costeira ou Amazônica sobre o Sul da Amazônia, nos meses de novembro a março no período 1999 a 2010. Um algoritmo objetivo na identificação da ocorrência de ZCAS foi esquematizado e a classificação em termos linguísticos permitiu categorizar em diferentes tipos. Durante os períodos de ZCAS, a possibilidade de ocorrer chuvas fortes diárias (> 20mm é mais de duas vezes maior do que a climatologia. ZCAS Amazônicas e costeiras produzem aproximadamente 71,4% da precipitação, referentes aos meses de janeiro a março representando 64% dos episódios atuantes no Sul da Amazônia.

  18. Inter-comparison of Dose Distributions Calculated by FLUKA, GEANT4, MCNP, and PHITS for Proton Therapy

    Science.gov (United States)

    Yang, Zi-Yi; Tsai, Pi-En; Lee, Shao-Chun; Liu, Yen-Chiang; Chen, Chin-Cheng; Sato, Tatsuhiko; Sheu, Rong-Jiun

    2017-09-01

    The dose distributions from proton pencil beam scanning were calculated by FLUKA, GEANT4, MCNP, and PHITS, in order to investigate their applicability in proton radiotherapy. The first studied case was the integrated depth dose curves (IDDCs), respectively from a 100 and a 226-MeV proton pencil beam impinging a water phantom. The calculated IDDCs agree with each other as long as each code employs 75 eV for the ionization potential of water. The second case considered a similar condition of the first case but with proton energies in a Gaussian distribution. The comparison to the measurement indicates the inter-code differences might not only due to different stopping power but also the nuclear physics models. How the physics parameter setting affect the computation time was also discussed. In the third case, the applicability of each code for pencil beam scanning was confirmed by delivering a uniform volumetric dose distribution based on the treatment plan, and the results showed general agreement between each codes, the treatment plan, and the measurement, except that some deviations were found in the penumbra region. This study has demonstrated that the selected codes are all capable of performing dose calculations for therapeutic scanning proton beams with proper physics settings.

  19. Efficiency corrections in determining the 137Cs inventory of environmental soil samples by using relative measurement method and GEANT4 simulations

    International Nuclear Information System (INIS)

    Li, Gang; Liang, Yongfei; Xu, Jiayun; Bai, Lixin

    2015-01-01

    The determination of 137 Cs inventory is widely used to estimate the soil erosion or deposition rate. The generally used method to determine the activity of volumetric samples is the relative measurement method, which employs a calibration standard sample with accurately known activity. This method has great advantages in accuracy and operation only when there is a small difference in elemental composition, sample density and geometry between measuring samples and the calibration standard. Otherwise it needs additional efficiency corrections in the calculating process. The Monte Carlo simulations can handle these correction problems easily with lower financial cost and higher accuracy. This work presents a detailed description to the simulation and calibration procedure for a conventionally used commercial P-type coaxial HPGe detector with cylindrical sample geometry. The effects of sample elemental composition, density and geometry were discussed in detail and calculated in terms of efficiency correction factors. The effect of sample placement was also analyzed, the results indicate that the radioactive nuclides and sample density are not absolutely uniform distributed along the axial direction. At last, a unified binary quadratic functional relationship of efficiency correction factors as a function of sample density and height was obtained by the least square fitting method. This function covers the sample density and height range of 0.8–1.8 g/cm 3 and 3.0–7.25 cm, respectively. The efficiency correction factors calculated by the fitted function are in good agreement with those obtained by the GEANT4 simulations with the determination coefficient value greater than 0.9999. The results obtained in this paper make the above-mentioned relative measurements more accurate and efficient in the routine radioactive analysis of environmental cylindrical soil samples. - Highlights: • Determination of 137 Cs inventory in environmental soil samples by using relative

  20. The GEANT4 simulation study of the characteristic γ-ray spectrum of TNT under soil induced by DT neutron

    International Nuclear Information System (INIS)

    Qin Xue; Han Jifeng; Yang Chaowen

    2014-01-01

    The characteristic γ-ray spectrum of TNT under soil induced by DT neutron is measured based on the PFTNA demining system. GEANT4 Monte Carlo simulation toolkit is used to simulate the whole experimental procedure. The simulative spectrum is compared with the experimental spectrum. The result shows that they are mainly consistent. It is for the first time to analyze the spectrum by Monte Carlo simulation, the share of the background sources such as neutron, gamma are obtained, the contribution that the experimental apparatus such as shielding, detector sleeve, moderator make to the background is analysed. The study found that the effective gamma signal (from soil and TNT) is only 29% of the full-spectrum signal, and the background signal is more than 68% of the full-spectrum signal, which is mainly produced in the shielding and the detector sleeve. The simulation result shows that by gradually improving the shielding and the cadmium of the detector sleeve, the share of the effective gamma signal can increase to 36% and the background signal can fell 7% eventually. (authors)

  1. Monte Carlo simulation of MOSFET dosimeter for electron backscatter using the GEANT4 code.

    Science.gov (United States)

    Chow, James C L; Leung, Michael K K

    2008-06-01

    The aim of this study is to investigate the influence of the body of the metal-oxide-semiconductor field effect transistor (MOSFET) dosimeter in measuring the electron backscatter from lead. The electron backscatter factor (EBF), which is defined as the ratio of dose at the tissue-lead interface to the dose at the same point without the presence of backscatter, was calculated by the Monte Carlo simulation using the GEANT4 code. Electron beams with energies of 4, 6, 9, and 12 MeV were used in the simulation. It was found that in the presence of the MOSFET body, the EBFs were underestimated by about 2%-0.9% for electron beam energies of 4-12 MeV, respectively. The trend of the decrease of EBF with an increase of electron energy can be explained by the small MOSFET dosimeter, mainly made of epoxy and silicon, not only attenuated the electron fluence of the electron beam from upstream, but also the electron backscatter generated by the lead underneath the dosimeter. However, this variation of the EBF underestimation is within the same order of the statistical uncertainties as the Monte Carlo simulations, which ranged from 1.3% to 0.8% for the electron energies of 4-12 MeV, due to the small dosimetric volume. Such small EBF deviation is therefore insignificant when the uncertainty of the Monte Carlo simulation is taken into account. Corresponding measurements were carried out and uncertainties compared to Monte Carlo results were within +/- 2%. Spectra of energy deposited by the backscattered electrons in dosimetric volumes with and without the lead and MOSFET were determined by Monte Carlo simulations. It was found that in both cases, when the MOSFET body is either present or absent in the simulation, deviations of electron energy spectra with and without the lead decrease with an increase of the electron beam energy. Moreover, the softer spectrum of the backscattered electron when lead is present can result in a reduction of the MOSFET response due to stronger

  2. A self-sufficient and general method for self-absorption correction in gamma-ray spectrometry using GEANT4

    International Nuclear Information System (INIS)

    Hurtado, S.; Villa, M.; Manjon, G.; Garcia-Tenorio, R.

    2007-01-01

    This paper presents a self-sufficient and general method for measurement of the activity of low-level gamma-emitters in voluminous samples by gamma-ray spectrometry with a coaxial germanium detector. Due to self-absorption within the sample, the full-energy peak efficiency of low-energy emitters in semiconductor gamma-spectrometers depends strongly on a number of factors including sample composition, density, sample size and gamma-ray energy. As long as those commented factors are well characterized, the influence of self-absorption in the full-energy peak efficiency of low-energy emitters can be calculated using Monte Carlo method based on GEANT4 code for each individual sample. However this task is quite tedious and time consuming. In this paper, we propose an alternative method to determine this influence for voluminous samples of unknown composition. Our method combines both transmission measurements and Monte Carlo simulations, avoiding the application of Monte Carlo full-energy peak efficiency determinations for each individual sample. To test the accuracy and precision of the proposed method, we have calculated 210 Pb activity in sediments samples from an estuary located in the vicinity of several phosphates factories with the proposed method, comparing the obtained results with the ones determined in the same samples using two alternative radiometric techniques

  3. Optimization of 6LiF:ZnS(Ag) scintillator light yield using GEANT4

    Science.gov (United States)

    Yehuda-Zada, Y.; Pritchard, K.; Ziegler, J. B.; Cooksey, C.; Siebein, K.; Jackson, M.; Hurlbut, C.; Kadmon, Y.; Cohen, Y.; Ibberson, R. M.; Majkrzak, C. F.; Maliszewskyj, N. C.; Orion, I.; Osovizky, A.

    2018-06-01

    A new cold neutron detector has been developed at the NIST Center for Neutron Research (NCNR) for the CANDoR (Chromatic Analysis Neutron Diffractometer or Reflectometer) project. Geometric and performance constraints dictate that this detector be exceptionally thin (∼ 2 mm). For this reason, the design of the detector consists of a 6LiF:ZnS(Ag) scintillator with embedded wavelength shifting (WLS) fibers. We used the GEANT4 package to simulate neutron capture and light transport in the detector to optimize the composition and arrangement of materials to satisfy the competing requirements of high neutron capture probability and light production and transport. In the process, we have developed a method for predicting light collection and total neutron detection efficiency for different detector configurations. The simulation was performed by adjusting crucial parameters such as the scintillator stoichiometry, light yield, component grain size, WLS fiber geometry, and reflectors at the outside edges of the scintillator volume. Three different detector configurations were fabricated and their test results were correlated with the simulations. Through this correlation we have managed to find a common photon threshold for the different detector configurations which was then used to simulate and predict the efficiencies for many other detector configurations. New detectors that have been fabricated based on simulation results yielding the desired sensitivity of 90% for 3.27 meV (5 Å) cold neutrons. The simulation has proven to be a useful tool by dramatically reducing the development period and the required number of detector prototypes. It can be used to test new designs with different thicknesses and different target neutron energies.

  4. Mucocele fronto-ethmoïdale geante avec extension intracranienne ...

    African Journals Online (AJOL)

    Mucocele fronto-ethmoïdale geante avec extension intracranienne: a propos d'un cas et revue de la litterature. A Kabre, DS Zabsonre, Y Haro. Abstract. Les mucocèles sont des pseudotumeurs kystiques développées aux dépens des sinus paranasaux. D'évolution lente et silencieuse elles se révèlent le plus souvent par ...

  5. Influencia del advergaming en los jóvenes universitarios de Lima

    Directory of Open Access Journals (Sweden)

    Alice Garrido Gallardo

    2014-11-01

    Full Text Available En tiempos donde el consumidor es capaz de encontrar lo que desea sin ser interrumpido por la publicidad, los anunciantes ven necesaria la tarea de expandir sus mensajes por medio de nuevas alternativas que acerquen al público con la marca de manera atractiva. El advergame forma parte de estas nuevas herramientas ya que busca fidelizar al consumidor mediante juegos interactivos que representen los valores, características y beneficios de la marca. Para conocer cuál es la influencia de esta herramienta publicitaria en los jóvenes de la ciudad de Lima, este artículo realiza un análisis sobre la actitud que ellos generan hacia la marca dependiendo del tratamiento que se le da en el juego, el tiempo de exposición y otras variables.

  6. Object-oriented analysis and design of a GEANT based detector simulator

    International Nuclear Information System (INIS)

    Amako, K.; Kanzaki, J.; Sasaki, T.; Takaiwa, Y.; Nakagawa, Y.; Yamagata, T.

    1994-01-01

    The authors give a status report of the project to design a detector simulation program by reengineering GEANT with the object-oriented methodology. They followed the Object Modeling Technique. They explain the object model they constructed. Also problems of the technique found during their study are discussed

  7. Capture reactions at astrophysically relevant energies: extended gas target experiments and GEANT simulations

    CERN Document Server

    Kölle, V; Braitmayer, S E; Mohr, P J; Wilmes, S; Staudt, G; Hammer, J W; Jäger, M; Knee, H; Kunz, R; Mayer, A

    1999-01-01

    Several resonances of the capture reaction sup 2 sup 0 Ne(alpha, gamma) sup 2 sup 4 Mg were measured using an extended windowless gas target system. Detailed GEANT simulations were performed to derive the strength and the total width of the resonances from the measured yield curve. The crucial experimental parameters, which are mainly the density profile in the gas target and the efficiency of the gamma-ray detector, were analyzed by a comparison between the measured data and the corresponding simulation calculations. The excellent agreement between the experimental data and the simulations gives detailed insight into these parameters. (author)

  8. GEANT4 simulation of the neutron background of the C$_6$D$_6$ set-up for capture studies at n_TOF

    CERN Document Server

    Žugec, P.; Bosnar, D.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortés, G.; Cortés-Giraldo, M.A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Duran, I.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A.R.; Giubrone, G.; Gómez-Hornillos, M.B.; Gonçalves, I.F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Heinitz, S.; Jenkins, D.G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Krtička, M.; Kroll, J.; Langer, C.; Lederer, C.; Leeb, H.; Leong, L.S.; Lo Meo, S.; Losito, R.; Manousos, A.; Marganiec, J.; Martìnez, T.; Massimi, C.; Mastinu, P.F.; Mastromarco, M.; Meaze, M.; Mendoza, E.; Mengoni, A.; Milazzo, P.M.; Mingrone, F.; Mirea, M.; Mondalaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Plompen, A.; Praena, J.; Quesada, J.M.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J.L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M.J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.

    2014-05-09

    The neutron sensitivity of the C$_6$D$_6$ detector setup used at n_TOF for capture measurements has been studied by means of detailed GEANT4 simulations. A realistic software replica of the entire n_TOF experimental hall, including the neutron beam line, sample, detector supports and the walls of the experimental area has been implemented in the simulations. The simulations have been analyzed in the same manner as experimental data, in particular by applying the Pulse Height Weighting Technique. The simulations have been validated against a measurement of the neutron background performed with a $^\\mathrm{nat}$C sample, showing an excellent agreement above 1 keV. At lower energies, an additional component in the measured $^\\mathrm{nat}$C yield has been discovered, which prevents the use of $^\\mathrm{nat}$C data for neutron background estimates at neutron energies below a few hundred eV. The origin and time structure of the neutron background have been derived from the simulations. Examples of the neutron backg...

  9. Analysis of Relative Biological Effectiveness of Proton Beams and Isoeffective Dose Profiles Using Geant4

    Directory of Open Access Journals (Sweden)

    Hosseini M. A.

    2017-06-01

    Full Text Available Background: The assessment of RBE quantity in the treatment of cancer tumors with proton beams in treatment planning systems (TPS is of high significance. Given the significance of the issue and the studies conducted in the literature, this quantity is fixed and is taken as equal to 1.1. Objective: The main objective of this study was to assess RBE quantity of proton beams and their variations in different depths of the tumor. This dependency makes RBE values used in TPS no longer be fixed as they depend on the depth of the tumor and therefore this dependency causes some changes in the physical dose profile. Materials and Methods: The energy spectrum of protons was measured at various depths of the tumor using proton beam simulations and well as the complete simulation of a cell to a pair of DNA bases through Monte Carlo GEANT4. The resulting energy spectrum was used to estimate the number of double-strand breaks generated in cells. Finally, RBE values were calculated in terms of the penetration depth in the tumor. Results and Conclusion: The simulation results show that the RBE value not fixed terms of the depth of the tumor and it differs from the clinical value of 1.1 at the end of the dose profile and this will lead to a non-uniform absorbed dose profile. Therefore, to create a uniform impact dose area, deep-finishing systems need to be designed by taking into account deep RBE values.

  10. Estudo da variação da resistência ao cisalhamento do resíduo solido urbano devido a presença de plástico mole

    OpenAIRE

    Gawlik, Francismara Martins

    2014-01-01

    A influencia do plástico mole na resistência ao cisalhamento do resíduo solido urbano (RSU) vem sendo alvo constante de estudo em virtude da sua enorme relevância nesta questão. No entanto trata-se de um tema complexo, visto que, são muitas as variáveis relacionadas ao problema, tais como, a quantidade de plástico, influencia do chorume em contanto com o plástico, inclinação do plástico em relação aos esforços normais e cisalhantes, resistência à tração do plástico, questões relacionadas à mo...

  11. Influencia da espessura das laminas e da cola na madeira laminada colada

    OpenAIRE

    Bohn, Adolar Ricardo

    1995-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnologico Estuda a influência que a espessura das lâminas tem no desempenho mecânico de vigas de madeira laminada colada, usando como parâmetros o módulo de elasticidade e resistência de ruptura na flexão. Faz um estudo sobre a possibilidade de diluição da cola e determina um percentual de diluição adequado para o Pinus Taeda e Pinus Elliottii.

  12. Exploring the Physics Limitations of Compact High Gradient Accelerating Structures Simulations of the Electron Current Spectrometer Setup in Geant4

    CERN Document Server

    Van Vliet, Philine Julia

    2017-01-01

    The high field gradient of 100 MV/m that will be applied to the accelerator cavities of the Compact Linear Collider (CLIC), gives rise to the problem of RF breakdowns. The field collapses and a plasma of electrons and ions is being formed in the cavity, preventing the RF field from penetrating the cavity. Electrons in the plasma are being accelerated and ejected out, resulting in a breakdown current up to a few Amp`eres, measured outside the cavities. These breakdowns lead to luminosity loss, so reducing their amount is of great importance. For this, a better understanding of the physics behind RF breakdowns is needed. To study these breakdowns, the XBox 2 test facility has a spectrometer setup installed after the RF cavity that is being conditioned. For this report, a simulation of this spectrometer setup has been made using Geant4. Once a detailed simulation of the RF field and cavity has been made, it can be connected to this simulation of the spectrometer setup and used to recreate the data that has b...

  13. Comparison of SRIM, MCNPX and GEANT simulations with experimental data for thick Al absorbers

    International Nuclear Information System (INIS)

    Evseev, Ivan G.; Schelin, Hugo R.; Paschuk, Sergei A.; Milhoretto, Edney; Setti, Joao A.P.; Yevseyeva, Olga; Assis, Joaquim T. de; Hormaza, Joel M.; Diaz, Katherin S.; Lopes, Ricardo T.

    2010-01-01

    Proton computerized tomography deals with relatively thick targets like the human head or trunk. In this case precise analytical calculation of the proton final energy is a rather complicated task, thus the Monte Carlo simulation stands out as a solution. We used the GEANT4.8.2 code to calculate the proton final energy spectra after passing a thick Al absorber and compared it with the same conditions of the experimental data. The ICRU49, Ziegler85 and Ziegler2000 models from the low energy extension pack were used. The results were also compared with the SRIM2008 and MCNPX2.4 simulations, and with solutions of the Boltzmann transport equation in the Fokker-Planck approximation.

  14. Comparison of SRIM, MCNPX and GEANT simulations with experimental data for thick Al absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Evseev, Ivan G. [Federal University of Technology-Parana-UTFPR, Av.7 de Setembro 3165, Curitiba-PR (Brazil); Schelin, Hugo R. [Federal University of Technology-Parana-UTFPR, Av.7 de Setembro 3165, Curitiba-PR (Brazil)], E-mail: schelin@utfpr.edu.br; Paschuk, Sergei A.; Milhoretto, Edney; Setti, Joao A.P. [Federal University of Technology-Parana-UTFPR, Av.7 de Setembro 3165, Curitiba-PR (Brazil); Yevseyeva, Olga; Assis, Joaquim T. de [Instituto Politecnico da UERJ, Rua Alberto Rangel s/n, Nova Friburgo-RJ (Brazil); Hormaza, Joel M. [Instituto de Biociencias da UNESP, Distrito de Rubiao Junior s/n, Botucatu-SP (Brazil); Diaz, Katherin S. [CEADEN, Calle 30 502 e/5ta y 7ma Avenida, Playa, Ciudad Habana (Cuba); Lopes, Ricardo T. [Laboratorio de Instrumentacao Nuclear, COPPE, UFRJ, Rio de Janeiro-RJ (Brazil)

    2010-04-15

    Proton computerized tomography deals with relatively thick targets like the human head or trunk. In this case precise analytical calculation of the proton final energy is a rather complicated task, thus the Monte Carlo simulation stands out as a solution. We used the GEANT4.8.2 code to calculate the proton final energy spectra after passing a thick Al absorber and compared it with the same conditions of the experimental data. The ICRU49, Ziegler85 and Ziegler2000 models from the low energy extension pack were used. The results were also compared with the SRIM2008 and MCNPX2.4 simulations, and with solutions of the Boltzmann transport equation in the Fokker-Planck approximation.

  15. O capital humano e a segurança dos alimentos: um olhar humanista na prática da alimentação coletiva

    OpenAIRE

    Rafael Almeida Ferreira de Abreu

    2015-01-01

    O presente estudo teve por objetivos: 1) caracterizar o Perfil Socioeconômico dos colaboradores; 2) caracterizar o Clima Organizacional; 3) caracterizar Comprometimento Organizacional; e 4) caracterizar e mapear o comportamento organizacional e verificar suas influencias no cumprimento da Boas Práticas de Higiene e Manipulação dos Alimentos. Refere-se a um estudo de caso com enfoque participativo utilizando-se de entrevistas, por se tratar de uma pesquisa essencialmente qualitativa. Concluira...

  16. Geant4 simulation for a study of a possible use of carbon ions pencil beam for the treatment of ocular melanomas with the active scanning system at CNAO Centre

    International Nuclear Information System (INIS)

    Farina, E.; Piersimoni, P.; Riccardi, C.; Rimoldi, A.; Tamborini, A.; Ciocca, M.

    2015-01-01

    The aim of this work is to validate the Geant4 application reproducing the CNAO (National Centre for Oncological Hadrontherapy) beamline and to study of a possible use of carbon ion pencil beams for the treatment of ocular melanomas at the CNAO Centre. The promising aspect of carbon ions radiotherapy for the treatment of this disease lies in its superior relative radiobiological effectiveness (RBE). The Monte Carlo Geant4 toolkit is used to simulate the complete CNAO extraction beamline, with the active and passive components along it. A human eye modeled detector, including a realistic target tumor volume, is used as target. Cross check with previous studies at CNAO using protons allows comparisons on possible benefits on using such a technique with respect to proton beams. Before the eye-detector irradiation a validation of the Geant4 simulation with CNAO experimental data is carried out with both carbon ions and protons. Important beam parameters such as the transverse FWHM and scanned radiation field 's uniformity are tested within the simulation and compared with experimental measurements at CNAO Centre. The physical processes involved in secondary particles generation by carbon ions and protons in the eye-detector are reproduced to take into account the additional dose to the primary beam given to irradiated eye's tissues. A study of beam shaping is carried out to produce a uniform 3D dose distribution (shaped on the tumor) by the use of a spread out Bragg peak. The eye-detector is then irradiated through a two dimensional transverse beam scan at different depths. In the use case the eye-detector is rotated of an angle of 40 deg. in the vertical direction, in order to mis-align the tumor from healthy tissues in front of it. The treatment uniformity on the tumor in the eye-detector is tested. For a more quantitative description of the deposited dose in the eye-detector and for the evaluation of the ratio between the dose deposited in the tumor and

  17. Geant4 simulation for a study of a possible use of carbon ions pencil beam for the treatment of ocular melanomas with the active scanning system at CNAO Centre

    Energy Technology Data Exchange (ETDEWEB)

    Farina, E. [University of Pavia-Department of Physics, via Bassi 6, 27100 Pavia (Italy); Piersimoni, P. [Division of Radiation Research, Loma Linda University, Loma Linda, CA 92354 (United States); Riccardi, C.; Rimoldi, A.; Tamborini, A. [University of Pavia-Department of Physics, via Bassi 6, 27100 Pavia (Italy); INFN Section of Pavia, via Bassi 6, 27100 Pavia (Italy); Ciocca, M. [Medical Physics Unit, Centro Nazionale di Adroterapia Oncologica - CNAO Foundation, Strada Campeggi 53, 27100 Pavia (Italy)

    2015-07-01

    The aim of this work is to validate the Geant4 application reproducing the CNAO (National Centre for Oncological Hadrontherapy) beamline and to study of a possible use of carbon ion pencil beams for the treatment of ocular melanomas at the CNAO Centre. The promising aspect of carbon ions radiotherapy for the treatment of this disease lies in its superior relative radiobiological effectiveness (RBE). The Monte Carlo Geant4 toolkit is used to simulate the complete CNAO extraction beamline, with the active and passive components along it. A human eye modeled detector, including a realistic target tumor volume, is used as target. Cross check with previous studies at CNAO using protons allows comparisons on possible benefits on using such a technique with respect to proton beams. Before the eye-detector irradiation a validation of the Geant4 simulation with CNAO experimental data is carried out with both carbon ions and protons. Important beam parameters such as the transverse FWHM and scanned radiation field 's uniformity are tested within the simulation and compared with experimental measurements at CNAO Centre. The physical processes involved in secondary particles generation by carbon ions and protons in the eye-detector are reproduced to take into account the additional dose to the primary beam given to irradiated eye's tissues. A study of beam shaping is carried out to produce a uniform 3D dose distribution (shaped on the tumor) by the use of a spread out Bragg peak. The eye-detector is then irradiated through a two dimensional transverse beam scan at different depths. In the use case the eye-detector is rotated of an angle of 40 deg. in the vertical direction, in order to mis-align the tumor from healthy tissues in front of it. The treatment uniformity on the tumor in the eye-detector is tested. For a more quantitative description of the deposited dose in the eye-detector and for the evaluation of the ratio between the dose deposited in the tumor and

  18. Monte Carlo simulations of dose distribution in water phantom for monoenergetic photon sources in the energy range of 20 keV and 2 MeV using a customized GEANT4 distribution

    International Nuclear Information System (INIS)

    Heredia, Eduardo; Rodrigues Jr, Orlando; Campos, Leticia Lucente

    2008-01-01

    Full text: Monte Carlo simulation methods are important tools in the areas of radiation transport and dosimetry, assisting in the radiation therapy treatment planning, study of energy deposition in complex systems and aid in the agreement the experimental results in the research of new materials. However, two aspects can affect the use of these tools: complexity in real world problems transposition to the simulation environment and difficulty in computational codes utilization. The objective of this work is to present a free software distribution based in the GEANT4 Monte Carlo code. The distribution was customized with the addition of tools for the development, visualization and data analysis in a software package with simplified installation and attended configuration. A wizard tool was developed and incorporated to the software package aiming to assist the user in the simulation skeleton creation and the election of the compilation and link flags for new models of simulation in the area of the radiation dosimetry. This software distribution is part of a wider project for the development of an infrastructure based in the GEANT4 for the radiation transport simulation under the perspective of a non centered computational architecture in dosimetry. The absorbed dose distribution in water phantom was simulated for monoenergetic photon sources with energies between 20 keV and 2 MeV. All results and analyses were generated with the tools incorporated in the software package. (author)

  19. Reaction Cross Section Calculations in Neutron Induced Reactions and GEANT4 Simulation of Hadronic Interactions for the Reactor Moderator Material BeO

    Directory of Open Access Journals (Sweden)

    Veli ÇAPALI

    2016-05-01

    Full Text Available BeO is one of the most common moderator material for neutron moderation; due to its high density, neutron capture cross section and physical-chemical properties that provides usage at elevated temperatures. As it’s known, for various applications in the field of reactor design and neutron capture, reaction cross–section data are required. The cross–sections of (n,α, (n,2n, (n,t, (n,EL and (n,TOT reactions for 9Be and 16O nuclei have been calculated by using TALYS 1.6 Two Component Exciton model and EMPIRE 3.2 Exciton model in this study. Hadronic interactions of low energetic neutrons and generated isotopes–particles have been investigated for a situation in which BeO was used as a neutron moderator by using GEANT4, which is a powerful simulation software. In addition, energy deposition along BeO material has been obtained. Results from performed calculations were compared with the experimental nuclear reaction data exist in EXFOR.

  20. Evaluation of the fluence to dose conversion coefficients for high energy neutrons using a voxel phantom coupled with the GEANT4 code

    CERN Document Server

    Paganini, S

    2005-01-01

    Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from Galactic cosmic radiation. Crews of future high-speed commercial flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the male adult voxels phantom MAX, developed in the Nuclear Energy Department of Pernambuco Federal University in Brazil, has been coupled with the Monte Carlo simulation code GEANT4. This toolkit, distributed and upgraded from the international scientific community of CERN/Switzerland, simulates thermal to ultrahigh energy neutrons transport and interactions in the matter. The high energy neutrons are pointed as the component that contribute about 70% of the neutron effective dose that represent the 35% to 60% total dose at aircraft altitude. In this research calculations of conversion coefficients from fluence to effective dose are performed for neutrons of energies from 100 MeV ...

  1. As raízes da arquitectura japonesa na obra de Tadao Ando : Museu de Arte Moderna de Fort Worth e Templo da Água

    OpenAIRE

    Martins, Pedro Miguel Sobral, 1986-

    2017-01-01

    Dissertação de mestrado integrado em Arquitectura, Universidade Lusíada de Lisboa, 2013 Exame público realizado em 26 de Fevereiro de 2014 Esta dissertação tem por base a análise dos conceitos da estética e arquitectura tradicionais do Japão, à luz da sua influência e contemporaneidade no momento presente. Foi analisada, a integração e contributo das correntes religiosas que maior influencia tiveram na definição dos conceitos de belo, bem como, o diálogo destes princípios estéticos c...

  2. Simulation, optimization and testing of a novel high spatial resolution X-ray imager based on Zinc Oxide nanowires in Anodic Aluminium Oxide membrane using Geant4

    Science.gov (United States)

    Esfandi, F.; Saramad, S.

    2015-07-01

    In this work, a new generation of scintillator based X-ray imagers based on ZnO nanowires in Anodized Aluminum Oxide (AAO) nanoporous template is characterized. The optical response of ordered ZnO nanowire arrays in porous AAO template under low energy X-ray illumination is simulated by the Geant4 Monte Carlo code and compared with experimental results. The results show that for 10 keV X-ray photons, by considering the light guiding properties of zinc oxide inside the AAO template and suitable selection of detector thickness and pore diameter, the spatial resolution less than one micrometer and the detector detection efficiency of 66% are accessible. This novel nano scintillator detector can have many advantages for medical applications in the future.

  3. Simulation, optimization and testing of a novel high spatial resolution X-ray imager based on Zinc Oxide nanowires in Anodic Aluminium Oxide membrane using Geant4

    International Nuclear Information System (INIS)

    Esfandi, F.; Saramad, S.

    2015-01-01

    In this work, a new generation of scintillator based X-ray imagers based on ZnO nanowires in Anodized Aluminum Oxide (AAO) nanoporous template is characterized. The optical response of ordered ZnO nanowire arrays in porous AAO template under low energy X-ray illumination is simulated by the Geant4 Monte Carlo code and compared with experimental results. The results show that for 10 keV X-ray photons, by considering the light guiding properties of zinc oxide inside the AAO template and suitable selection of detector thickness and pore diameter, the spatial resolution less than one micrometer and the detector detection efficiency of 66% are accessible. This novel nano scintillator detector can have many advantages for medical applications in the future

  4. Simulating cosmic radiation absorption and secondary particle production of solar panel layers of Low Earth Orbit (LEO) satellite with GEANT4

    Science.gov (United States)

    Yiǧitoǧlu, Merve; Veske, Doǧa; Nilüfer Öztürk, Zeynep; Bilge Demirköz, Melahat

    2016-07-01

    All devices which operate in space are exposed to cosmic rays during their operation. The resulting radiation may cause fatal damages in the solid structure of devices and the amount of absorbed radiation dose and secondary particle production for each component should be calculated carefully before the production. Solar panels are semiconductor solid state devices and are very sensitive to radiation. Even a short term power cut-off may yield a total failure of the satellite. Even little doses of radiation can change the characteristics of solar cells. This deviation can be caused by rarer high energetic particles as well as the total ionizing dose from the abundant low energy particles. In this study, solar panels planned for a specific LEO satellite, IMECE, are analyzed layer by layer. The Space Environment Information System (SPENVIS) database and GEANT4 simulation software are used to simulate the layers of the panels. The results obtained from the simulation will be taken in account to determine the amount of radiation protection and resistance needed for the panels or to revise the design of the panels.

  5. The GEANT4 toolkit capability in the hadron therapy field: simulation of a transport beam line

    International Nuclear Information System (INIS)

    Cirrone, G.A.P.; Cuttone, G.; Di Rosa, F.; Raffaele, L.; Russo, G.; Guatelli, S.; Pia, M.G.

    2006-01-01

    At Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare of Catania (Sicily, Italy), the first Italian hadron therapy facility named CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) has been realized. Inside CATANA 62 MeV proton beams, accelerated by a superconducting cyclotron, are used for the radiotherapeutic treatments of some types of ocular tumours. Therapy with hadron beams still represents a pioneer technique, and only a few centers worldwide can provide this advanced specialized cancer treatment. On the basis of the experience so far gained, and considering the future hadron-therapy facilities to be developed (Rinecker, Munich Germany, Heidelberg/GSI, Darmstadt, Germany, PSI Villigen, Switzerland, CNAO, Pavia, Italy, Centro di Adroterapia, Catania, Italy) we decided to develop a Monte Carlo application based on the GEANT4 toolkit, for the design, the realization and the optimization of a proton-therapy beam line. Another feature of our project is to provide a general tool able to study the interactions of hadrons with the human tissue and to test the analytical-based treatment planning systems actually used in the routine practice. All the typical elements of a hadron-therapy line, such as diffusers, range shifters, collimators and detectors were modelled. In particular, we simulated the Markus type ionization chamber and a Gaf Chromic film as dosimeters to reconstruct the depth (Bragg peak and Spread Out Bragg Peak) and lateral dose distributions, respectively. We validated our simulated detectors comparing the results with the experimental data available in our facility

  6. The GEANT4 toolkit capability in the hadron therapy field: simulation of a transport beam line

    Science.gov (United States)

    Cirrone, G. A. P.; Cuttone, G.; Di Rosa, F.; Raffaele, L.; Russo, G.; Guatelli, S.; Pia, M. G.

    2006-01-01

    At Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare of Catania (Sicily, Italy), the first Italian hadron therapy facility named CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) has been realized. Inside CATANA 62 MeV proton beams, accelerated by a superconducting cyclotron, are used for the radiotherapeutic treatments of some types of ocular tumours. Therapy with hadron beams still represents a pioneer technique, and only a few centers worldwide can provide this advanced specialized cancer treatment. On the basis of the experience so far gained, and considering the future hadron-therapy facilities to be developed (Rinecker, Munich Germany, Heidelberg/GSI, Darmstadt, Germany, PSI Villigen, Switzerland, CNAO, Pavia, Italy, Centro di Adroterapia, Catania, Italy) we decided to develop a Monte Carlo application based on the GEANT4 toolkit, for the design, the realization and the optimization of a proton-therapy beam line. Another feature of our project is to provide a general tool able to study the interactions of hadrons with the human tissue and to test the analytical-based treatment planning systems actually used in the routine practice. All the typical elements of a hadron-therapy line, such as diffusers, range shifters, collimators and detectors were modelled. In particular, we simulated the Markus type ionization chamber and a Gaf Chromic film as dosimeters to reconstruct the depth (Bragg peak and Spread Out Bragg Peak) and lateral dose distributions, respectively. We validated our simulated detectors comparing the results with the experimental data available in our facility.

  7. The GEANT4 toolkit capability in the hadron therapy field: simulation of a transport beam line

    Energy Technology Data Exchange (ETDEWEB)

    Cirrone, G.A.P. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, Catania (Italy); Cuttone, G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, Catania (Italy); Di Rosa, F. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, Catania (Italy); Raffaele, L. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, Catania (Italy); Russo, G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, Catania (Italy); Guatelli, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, Via Dodecaneso 33, Genova (Italy); Pia, M.G. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, Via Dodecaneso 33, Genova (Italy)

    2006-01-15

    At Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare of Catania (Sicily, Italy), the first Italian hadron therapy facility named CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) has been realized. Inside CATANA 62 MeV proton beams, accelerated by a superconducting cyclotron, are used for the radiotherapeutic treatments of some types of ocular tumours. Therapy with hadron beams still represents a pioneer technique, and only a few centers worldwide can provide this advanced specialized cancer treatment. On the basis of the experience so far gained, and considering the future hadron-therapy facilities to be developed (Rinecker, Munich Germany, Heidelberg/GSI, Darmstadt, Germany, PSI Villigen, Switzerland, CNAO, Pavia, Italy, Centro di Adroterapia, Catania, Italy) we decided to develop a Monte Carlo application based on the GEANT4 toolkit, for the design, the realization and the optimization of a proton-therapy beam line. Another feature of our project is to provide a general tool able to study the interactions of hadrons with the human tissue and to test the analytical-based treatment planning systems actually used in the routine practice. All the typical elements of a hadron-therapy line, such as diffusers, range shifters, collimators and detectors were modelled. In particular, we simulated the Markus type ionization chamber and a Gaf Chromic film as dosimeters to reconstruct the depth (Bragg peak and Spread Out Bragg Peak) and lateral dose distributions, respectively. We validated our simulated detectors comparing the results with the experimental data available in our facility.

  8. Teoria da mente e compreensão das emoções: um estudo comparativo com alunos do ensino fundamental

    OpenAIRE

    Ribas, Deyse Aparecida

    2011-01-01

    A teoria da mente, entendimento que as crianças elaboram acerca da mente, incluindo-se emoções, intenções, desejos e crenças, permite predizer o comportamento e formular o entendimento do mundo social. A compreensão das emoções, um dos aspectos constituintes da teoria da mente, também influencia o conhecimento sociocognitivo e parece estar intimamente ligada à trajetória de desenvolvimento social e ao ajustamento escolar. Tal constatação leva a indagar sobre como se daria a compreensão das em...

  9. Number distribution of leakage neutrons for single neutron emission event and one source emission event in multiplying medium for two variables - a GEANT4 study

    International Nuclear Information System (INIS)

    Roy, Arup Singha; Raman, Anand; Chaudhury, Probal; Thomas, Renju G.

    2018-01-01

    A quantitative knowledge about the neutron multiplying character of a neutron multiplying medium such as High enriched Uranium (HEU), Weapon Graded plutonium (WGPu) and similar special nuclear materials is essential for improving the probability of detection of these materials to check against illicit trafficking. The objective of this study is to gain a deeper insight in to the neutron and gamma multiplication behaviour of these materials. The leakage number distribution of neutron and gamma initiated by a source emission event (Spontaneous Fission) as well as single neutron emission event has been obtained in the course of this study. The computations for this study were carried out through GEANT4 simulation and also with the help of FREYA incorporated into it. This helped to carry out a detailed analysis of each history more realistically and obtain more reliable results

  10. Simulation calculations using the code Geant III for the EUROGAM device

    Energy Technology Data Exchange (ETDEWEB)

    Beck, F A; Curien, D; Duchene, G; France, G de; Wei, L [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires

    1992-08-01

    Simulation calculations are good tools to determine, at a low cost, the characteristics of a detector. It enables to change the geometry of the counter in an iterative way to optimize its response leading to the best performances for the whole multi-detector device. This kind of calculations have been performed using the Geant III code for the EUROGAM device. (author). 3 tabs., 5 figs.

  11. Reflexões e perspectivas sobre a inclusão e exclusão da disciplina de Filosofia no currículo escolar

    Directory of Open Access Journals (Sweden)

    Sandra Aparecida Batista

    2017-08-01

    Full Text Available este artigo por meio de pesquisa bibliográfica de abordagem qualitativa tece algumas reflexões acerca da problemática da inclusão e exclusão da disciplina de Filosofia no currículo escolar. O ensino da filosofia no Brasil tem suas origens no período colonial, perpassando pela ditadura militar, quando a mesma foi extinta das grades curriculares, pelo período da redemocratização, onde se deu a re-inclusão da disciplina como optativa e posteriormente como obrigatória, bem como da reforma do ensino médio, via Medida Provisória (MP nº. 746/2016, que trata da exclusão da disciplina no currículo escolar.  Neste sentido, há um entendimento de que este processo se dá por influencia das relações de poder embutidas no currículo, visto que o mesmo não é um elemento, simples programa ou quadro de conteúdos, mas, sobretudo um instrumento permeado por lutas e disputas hegemônicas que reflete o interesse da ideologia dominante, bem como da importância da disciplina na formação do pensamento reflexivo, autônomo, crítico e emancipatório. Como resultado evidenciou-se que a inclusão e exclusão da disciplina ocorrem por influencia das relações de poder embutidas no currículo escolar, de modo a atender interesses ideológicos e hegemônicos, independente das contribuições sociais e humanas da disciplina.

  12. Use of the GEANT4 Monte Carlo to determine three-dimensional dose factors for radionuclide dosimetry

    International Nuclear Information System (INIS)

    Amato, Ernesto; Italiano, Antonio; Minutoli, Fabio; Baldari, Sergio

    2013-01-01

    The voxel-level dosimetry is the most simple and common approach to internal dosimetry of nonuniform distributions of activity within the human body. Aim of this work was to obtain the dose “S” factors (mGy/MBqs) at the voxel level for eight beta and beta–gamma emitting radionuclides commonly used in nuclear medicine diagnostic and therapeutic procedures. We developed a Monte Carlo simulation in GEANT4 of a region of soft tissue as defined by the ICRP, divided into 11×11×11 cubic voxels, 3 mm in side. The simulation used the parameterizations of the electromagnetic interaction optimized for low energy (EEDL, EPDL). The decay of each radionuclide ( 32 P, 90 Y, 99m Tc, 177 Lu, 131 I, 153 Sm, 186 Re, 188 Re) were simulated homogeneously distributed within the central voxel (0,0,0), and the energy deposited in the surrounding voxels was mediated on the 8 octants of the three dimensional space, for reasons of symmetry. The results obtained were compared with those available in the literature. While the iodine deviations remain within 16%, for phosphorus, a pure beta emitter, the agreement is very good for self-dose (0,0,0) and good for the dose to first neighbors, while differences are observed ranging from −60% to +100% for voxels far distant from the source. The existence of significant differences in the percentage calculation of the voxel S factors, especially for pure beta emitters such as 32 P or 90 Y, has already been highlighted by other authors. These data can usefully extend the dosimetric approach based on the voxel to other radionuclides not covered in the available literature

  13. Simulation of silicon microdosimetry spectra in fast neutron therapy using the GEANT4 Monte Carlo toolkit

    International Nuclear Information System (INIS)

    Cornelius, I.M.; Rosenfeld, A.B.

    2003-01-01

    Microdosimetry is used to predict the biological effects of the densely ionizing radiation environments of hadron therapy and space. The creation of a solid state microdosimeter to replace the conventional Tissue Equivalent Proportional Counter (TEPC) is a topic of ongoing research. The Centre for Medical Radiation Physics has been investigating a technique using microscopic arrays of reverse biased PN junctions. A prototype silicon-on-insulator (SOI) microdosimeter was developed and preliminary measurements have been conducted at several hadron therapy facilities. Several factors impede the application of silicon microdosimeters to hadron therapy. One of the major limitations is that of tissue equivalence, ideally the silicon microdosimeter should provide a microdosimetry distribution identical to that of a microscopic volume of tissue. For microdosimetry in neutron fields, such as Fast Neutron Therapy, it is important that products resulting from neutron interactions in the non tissue equivalent sensitive volume do not contribute significantly to the spectrum. Experimental measurements have been conducted at the Gershenson Radiation Oncology Center, Harper Hospital, Detroit by Bradley et al. The aim was to provide a comparison with measurements performed with a TEPC under identical experimental conditions. Monte Carlo based calculations of these measurements were made using the GEANT4 Monte Carlo toolkit. Agreement between experimental and theoretical results was observed. The model illustrated the importance of neutron interactions in the non tissue equivalent sensitive volume and showed this effect to decrease with sensitive volume size as expected. Simulations were also performed for 1 micron cubic silicon sensitive volumes embedded in tissue equivalent material to predict the best case scenario for silicon microdosimetry in Fast Neutron Therapy

  14. Contribution to the energy calibration of GLAST-LAT's calorimeter and validation of hadronic cascade models available with GEANT4

    International Nuclear Information System (INIS)

    Bregeon, J.

    2005-09-01

    GLAST is the new generation of Gamma-ray telescope and should dramatically improve our knowledge of the gamma-ray sky when it is launched on September 7. 2007. Data from the beam test that was held at GANIL with low energy ions were analyzed in order to measure the light quenching factor of CsI for all kinds of ions from proton to krypton of energy between 0 and 73 MeV per nucleon. These results have been very useful to understand the light quenching for relativistic ions that was measured during the GSI beam test. The knowledge of light quenching in GLAST CsI detectors for high energy ions is required for the on-orbit calibration with cosmic rays to succeed. Hadronic background rejection is another major issue for GLAST, thus, all the algorithms rely on the GLAST official Monte-Carlo simulation, GlastRelease. Hadronic cascade data from the GSI beam test and from another beam test held at CERN on the SPS have been used to benchmark hadronic cascade simulation within the framework of GEANT4, on which GlastRelease is based. Testing the good reproduction of simple parameters in GLAST-like calorimeters for hadronic cascades generated by 1.7 GeV, 3.4 GeV, 10 GeV and 20 GeV protons or pions led us to the conclusion that at high energy the default LHEP model is good enough, whereas at low energy the Bertini intra-nuclear cascade model should be used. (author)

  15. PERCEPÇÃO DA INFLUÊNCIA DA GESTÃO ESTRATÉGICA DE PESSOAS NO COMPROMETIMENTO ORGANIZACIONAL

    Directory of Open Access Journals (Sweden)

    Vera Lúcia da Silva Ventura

    2014-12-01

    Full Text Available Este artigo apresenta os resultados de uma pesquisa realizada em uma Instituição de Ensino Superior. O objetivo foi investigar as percepções de docentes do ensino superior acerca da influência da gestão estratégica de pessoas no comprometimento organizacional. O estudo foi delineado pela pesquisa qualitativa e pelo método fenomenológico, com utilização da estratégia de pesquisa de estudo de caso único. Como estratégias de coleta de dados realizaram-se entrevistas, observação participante e pesquisa documental por meio de roteiros semi-estruturados. Esses dados foram tratados pelos procedimentos de análise de conteúdo e análise documental.  Os resultados indicaram que, pela percepção dos entrevistados, a gestão estratégica de pessoas influencia o comprometimento dos docentes com a instituição e com a sua missão profissional como professores. Verificou-se que os docentes da graduação percebem essa influência com ênfase no comprometimento afetivo, enquanto que os docentes da pós-graduação demonstram a percepção dessa influência, com maior relevância, no comprometimento normativo.

  16. Analisis de redes sociales y procesos de influencia en la toma de decision grupal

    Directory of Open Access Journals (Sweden)

    Jorge Ricardo Vivas

    2001-01-01

    Full Text Available En el presente trabajo se analizan los procesos de influencia por medio del estudio de las relaciones entre medidas convencionales y estructurales en tareas de toma de decisión grupal. Se exploraron los componentes de conectividad y prestigio como facilitadores del proceso de influencia; la conectividad por medio del flujo global, la participación, la densidad de la red ego centrada y la cohesión o distancia reticular. El prestigio se analizó por medio del status sociométrico, medidas de influencia y centralidad (grado, prestigio y poder y medidas de equivalencia estructural para delimitar roles y posiciones. Se utilizó la prueba Supervivencia en la Luna y participaron 70 alumnos de tercer año de la Carrera de Psicología. Los resultados muestran que existe una asociación significativa entre el conocimiento previo a la tarea y la influencia social medida como contribución al producto grupal, que las medidas de centralidad tienen relación con aspectos de la dinámica grupal y no con la contribución al producto y que los roles varían dentro y fuera de la tarea. La influencia está significativamente asociada a la densidad de la red personal. La interpretación de los resultados sugiere que las redes personales de baja densidad favorecen la capacidad de influencia en la producción grupal y que la alta cohesión y conectividad subgrupal la deterioran. También sugieren que las medidas de centralidad se relacionan con influencia en el tráfico comunicacional pero no con la productividad. Y que el status previo y el obtenido durante la actividad, no se vinculan con la producción.

  17. Use of the GEANT4 Monte Carlo to determine three-dimensional dose factors for radionuclide dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Amato, Ernesto, E-mail: eamato@unime.it [University of Messina, Department of Biomedical Sciences and of Morphologic and Functional Imaging, Section of Radiological Sciences (Italy); Italiano, Antonio [INFN – Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Messina (Italy); Minutoli, Fabio; Baldari, Sergio [University of Messina, Department of Biomedical Sciences and of Morphologic and Functional Imaging, Section of Radiological Sciences (Italy)

    2013-04-21

    The voxel-level dosimetry is the most simple and common approach to internal dosimetry of nonuniform distributions of activity within the human body. Aim of this work was to obtain the dose “S” factors (mGy/MBqs) at the voxel level for eight beta and beta–gamma emitting radionuclides commonly used in nuclear medicine diagnostic and therapeutic procedures. We developed a Monte Carlo simulation in GEANT4 of a region of soft tissue as defined by the ICRP, divided into 11×11×11 cubic voxels, 3 mm in side. The simulation used the parameterizations of the electromagnetic interaction optimized for low energy (EEDL, EPDL). The decay of each radionuclide ({sup 32}P, {sup 90}Y, {sup 99m}Tc, {sup 177}Lu, {sup 131}I, {sup 153}Sm, {sup 186}Re, {sup 188}Re) were simulated homogeneously distributed within the central voxel (0,0,0), and the energy deposited in the surrounding voxels was mediated on the 8 octants of the three dimensional space, for reasons of symmetry. The results obtained were compared with those available in the literature. While the iodine deviations remain within 16%, for phosphorus, a pure beta emitter, the agreement is very good for self-dose (0,0,0) and good for the dose to first neighbors, while differences are observed ranging from −60% to +100% for voxels far distant from the source. The existence of significant differences in the percentage calculation of the voxel S factors, especially for pure beta emitters such as {sup 32}P or {sup 90}Y, has already been highlighted by other authors. These data can usefully extend the dosimetric approach based on the voxel to other radionuclides not covered in the available literature.

  18. Influência germânica nos primórdios da enfermagem profissional na cidade do Recife, Pernambuco (1924-1927 Influencia germánica en los inicios de la enfermería profesional en la ciudad de Recife, Pernambuco (1924-1927 Germanic influence in the early days of professional nursing in the city of Recife, Pernambuco (1924-1927

    Directory of Open Access Journals (Sweden)

    Fátima Maria da Silva Abrão

    2010-06-01

    Full Text Available Estudo histórico-social, que teve como objetivo a análise da influência germânica no campo da saúde nos primórdios da enfermagem profissional na cidade do Recife, Pernambuco. Foi feita análise do conteúdo dos documentos à luz do pensamento de Bourdieu. Na interpretação dos dados, a noção de campo e poder foi utilizada de modo a contemplar as forças que contribuem para a formação do campo organizacional da enfermagem. O recorte temporal foi de 1924, com a vinda das enfermeiras alemãs para trabalhar no Hospital do Centenário (HC, até 1927, quando ocorre a saída da enfermeira administradora. Utilizaram-se fontes primárias e secundárias. Como resultado, observa-se que a cultura alemã exerceu forte influência no campo da saúde, comércio, indústria, economia e educação. A influência se dá nos primórdios da enfermagem profissional pelo reconhecimento da atuação das enfermeiras pela dedicação e abnegação aos enfermos no trabalho que desenvolviam.Estudio histórico-social, que tuvo como objetivo el análisis de la influencia germánica en el campo de la salud en los inicios de la enfermería profesional en la ciudad de Recife, Pernambuco. Fue realizado el análisis del contenido de los documentos bajo la óptica del pensamiento de Bourdieu. En la interpretación de los datos las nociones de campo y poder fueron utilizadas como forma de contemplar las fuerzas que contribuyen a la formación del campo organizacional de la enfermería. El corte de tiempo se produjo en 1924, con la llegada de las enfermeras alemanas para trabajar en el Hospital del Centenario (HC y se extendió hasta 1927, donde se presenta la salida de la enfermera administradora. Se utilizaron fuentes primarias y secundarias. Como resultado, se observa que la cultura alemana ejerció una fuerte influencia en el campo de la salud, en el comercio, industria, economía y educación. La influencia se presenta en los inicios de la enfermería profesional

  19. IMPORTÂNCIA E INTERACÇÕES DA INTENSIDADE DA DISTRIBUIÇÃO COM A PERFORMANCE: ESTUDO EXPLORATÓRIO DE ÁGUA ENGARRAFADA

    Directory of Open Access Journals (Sweden)

    Joana Cabeçadas

    2006-04-01

    Full Text Available Este estudo pretende abordar a importância da variável intensidade da distribuição como estratégia de marketing, bem como as interações com outras variáveis relevantes para as empresas. Tal análise revela-se extremamente importante, já que, para produtos para os quais não faz sentido adotar estratégias de diferenciação, as empresas devem compreender bem as implicações e determinantes da intensidade da distribuição. Procura-se avaliar a importância da competitividade da força de vendas, enquanto força interna. O estudo demonstra e justifica a relação positiva que existe entre a competitividade da força de vendas e as variáveis intensidade da distribuição e performance da força de vendas. Como o mercado em estudo é extremamente competitivo, evidencia-se a relevância da intensidade da competição. Verifica-se que um aumento dessa variável tem um impacto positivo na intensidade da distribuição e na performance da força de vendas. Na maioria dos casos confirma-se que a quota de mercado, enquanto medida de performance do ano anterior, influencia positivamente a nossa variável estratégica. Por sua vez, o aumento da intensidade da distribuição melhora a performance da força de vendas e, conseqüentemente, o desempenho da empresa.

  20. Variation of Bragg curve characteristic induced by changing the position of inhomogeneous material: Geant4 simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Park, So-Hyun; Jung, Won-Gyun; Suh, Tae-Suk [Catholic University, Seoul (Korea, Republic of); Jang, Hong-Seok; Choi, Byeong-Oak [Seoul St. Mary' s Hospital, Seoul (Korea, Republic of); Rah, Jeong-Eun; Park, Sun-Gyong; Lee, Se-Byeong [National Cancer Center, Ilsan (Korea, Republic of)

    2011-02-15

    When proton beam passes through the human body, the stopping power and the depth-dose distribution of the proton are influenced by the relative location among adjacent materials or the difference in material conditions. Our study demonstrates the effect of inhomogeneous materials placed in the Plateau and Bragg peak regions of the Bragg curve in water. We evaluated the Bragg peak position, range, penumbra and integrated doses by using the Geant4 simulation toolkit. The positions of inhomogeneities were selected as the proximal 36% and 50% points of the maximum dose, which indicates the location at entrance regions of the Plateau and the Bragg peak, respectively. Bone (density {rho} = 1.85 g/cm{sup 3}) and adipose tissue (density {rho} = 0.92 g/cm{sup 3}) were selected as inhomogeneous materials. The thickness of each material was varied by 0.1 cm between 0.1 cm and 1.0 cm. In addition, the initial energy of the proton beam was changed in 30 MeV steps between 108 MeV and 220 MeV. The effects of inhomogeneous conditions were performed for various parameters: Bragg peak position, range, penumbra width, full width at half maximum and dose of Bragg curve. A dose perturbation was observed in the region of the Bragg peak and inhomogeneous material, especially, When the bone equivalent material was inserted within the Bragg curve. However, there were no significant variations in the other parameters, except for the dose perturbation depending on the inserted location of each material. This study shows the characteristic changes in the Bragg curve due to inhomogeneous materials.

  1. Stochastic optimization of GeantV code by use of genetic algorithms

    Science.gov (United States)

    Amadio, G.; Apostolakis, J.; Bandieramonte, M.; Behera, S. P.; Brun, R.; Canal, P.; Carminati, F.; Cosmo, G.; Duhem, L.; Elvira, D.; Folger, G.; Gheata, A.; Gheata, M.; Goulas, I.; Hariri, F.; Jun, S. Y.; Konstantinov, D.; Kumawat, H.; Ivantchenko, V.; Lima, G.; Nikitina, T.; Novak, M.; Pokorski, W.; Ribon, A.; Seghal, R.; Shadura, O.; Vallecorsa, S.; Wenzel, S.

    2017-10-01

    GeantV is a complex system based on the interaction of different modules needed for detector simulation, which include transport of particles in fields, physics models simulating their interactions with matter and a geometrical modeler library for describing the detector and locating the particles and computing the path length to the current volume boundary. The GeantV project is recasting the classical simulation approach to get maximum benefit from SIMD/MIMD computational architectures and highly massive parallel systems. This involves finding the appropriate balance between several aspects influencing computational performance (floating-point performance, usage of off-chip memory bandwidth, specification of cache hierarchy, etc.) and handling a large number of program parameters that have to be optimized to achieve the best simulation throughput. This optimization task can be treated as a black-box optimization problem, which requires searching the optimum set of parameters using only point-wise function evaluations. The goal of this study is to provide a mechanism for optimizing complex systems (high energy physics particle transport simulations) with the help of genetic algorithms and evolution strategies as tuning procedures for massive parallel simulations. One of the described approaches is based on introducing a specific multivariate analysis operator that could be used in case of resource expensive or time consuming evaluations of fitness functions, in order to speed-up the convergence of the black-box optimization problem.

  2. Design and Construction of a Positron Emission Tomography (PET) Unit and Medical Applications with GEANT Detector Simulation Package

    Energy Technology Data Exchange (ETDEWEB)

    Karagoz, Muge [Bogazici Univ., Istanbul (Turkey)

    1998-01-01

    In order to investigate the possibility of the construction of a sample PET coincidence unit in our HEP laboratory, a setup with two face to face PMTs and two 2x8 Csi(Tl) scintillator matrices has been constructed. In this setup, 1-D projections of a pointlike 22 Na positron source at different angles have been measured. Using these projections a 2-D image has been formed. Monte Carlo studies of this setup have been implemented using the detector simulation tool in CERN program library, GEANT. Again with GEANT a sample human body is created to study the effects of proton therapy. Utilization of the simulation as a pretherapy tool is also investigated.

  3. A influência da iniciativa hospital amigo da criança na amamentação La influencia de la Iniciativa Hospital Amigo del Niño en el amamantamiento The influence of the 'Friend of Children Hospital' campaign on breast-feeding

    Directory of Open Access Journals (Sweden)

    Valéria Lerch Lunardi

    2004-12-01

    Full Text Available O trabalho investiga a percepção de mulheres que foram parturientes num Hospital Amigo da Criança (HAC sobre a influência dessa proposta na sua decisão de aleitar. Realizamos entrevistas semi-estruturadas enfocando o processo de aleitamento materno (AM, expectativas, vivências e importância da equipe de saúde. A análise de conteúdo dos dados realizou-se a partir dos "Dez Passos para o Sucesso do Aleitamento Materno". Constatamos que em situações reconhecidas pelas mulheres como problemáticas e não encontrando respostas que atenuassem diferentes desconfortos e o sofrimento vivenciados, frente ao seu desejo de amamentar, interromperam o AM. Consideramos que com a manutenção do apoio à mulher, pelo HAC, para o enfrentamento dessas dificuldades, sua influência pode ser decisiva para a continuidade do AM.El trabajo investiga la percepción de las mujeres que eran parturientas en un Hospital Amigo del Niño (HAN sobre la influencia de esta propuesta en su decisión de amamantar. Realizamos entrevistas semiestructuradas enfocando el proceso de amamantar (AM; las expectativas; las vivencias; la importancia del equipo de salud, entre otros. El análisis de contenido de los datos se realizó a partir de los «Diez Pasos para el Éxito de Amamantamiento Materno». Constatamos que en situaciones reconocidas por las mujeres como problemáticas y no encontrando respuestas que atenuaran diferentes incomodidades y el sufrimiento vivenciado, frente a su deseo de amamantar, interrumpieron el AM. Consideramos que con el mantenimiento del apoyo a la mujer, por el HAC para el enfrentamiento de esas dificultades, su influencia puede ser decisiva para la continuidad del AM.The paper investigates the awareness of women who gave birth in a 'Friend of Children' Hospital (FCH of the influence of this campaign on their decision to breast-feed. We conducted semi-structured interviews, focusing the maternal breast-feeding process, expectations, experiences

  4. Validation of GEANT3 simulation studies with a dual-head PMT ClearPET TM prototype

    CERN Document Server

    Ziemons, K; Streun, M; Pietrzyk, U

    2004-01-01

    The ClearPET TM project is proposed by working groups of the Crystal Clear Collaboration (CCC) to develop a 2/sup nd/ generation high performance small animal positron emission tomograph (PET). High sensitivity and high spatial resolution is foreseen for the ClearPET TM camera by using a phoswich arrangement combining mixed lutetium yttrium aluminum perovskite (LuYAP:Ce) and lutetium oxyorthosilicate (LSO) scintillating crystals. Design optimizations for the first photomultiplier tube (PMT) based ClearPET camera are done with a Monte-Carlo simulation package implemented on GEANT3 (CERN, Geneva, Switzerland). A dual-head prototype has been built to test the frontend electronics and was used to validate the implementation of the GEANT3 simulation tool. Multiple simulations were performed following the experimental protocols to measure the intrinsic resolution and the sensitivity profile in axial and radial direction. Including a mean energy resolution of about 27.0% the simulated intrinsic resolution is about (...

  5. Los mecanismos de influencia en el liderazgo

    OpenAIRE

    Arango Cardona, Patricia

    2016-01-01

    Este trabajo tiene como objetivo fundamental identificar las tácticas de influencia que utiliza el señor Carlos Pérez, gerente y socio principal de G. & M., en su trato cotidiano con sus colaboradores, así como la reacción de estos últimos ante dichas tácticas.

  6. Influencia de la práctica deportiva en la integración sensorial en niños: Evaluación estabilométrica

    OpenAIRE

    Gómez Sánchez, Stella Maris

    2016-01-01

    Tesis Doctoral leída en la Universidad Rey Juan Carlos de Madrid en 2013. Directores de la Tesis: Rafael Linares García-Valdecasas y D. Antonio Gil Crujera Objetivo: Evaluar la influencia de la actividad física en las oscilaciones posturales en niños y niñas sanos, así como los factores que pueden influir en el mantenimiento de la estabilidad postural. Métodos: Se incluyeron 39 niños y niñas que no realizaban deporte de manera regular y 44 niños y niñas que realizaban deporte al menos d...

  7. Development of a computational system based in the code GEANT4 for dosimetric evaluation in radiotherapy; Desenvolvimento de um sistema computacional baseado no Codigo GEANT4 para avaliacoes dosimetricas em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Alex Cristovao Holanda de

    2016-10-01

    The incidence of cancer has grown in Brazil, as well as around the world, following the change in the age profile of the population. One of the most important techniques and commonly used in cancer treatment is radiotherapy. Around 60% of new cases of cancer use radiation in at least one phase of treatment. The most used equipment for radiotherapy is a linear accelerator (Linac) which produces electron or X-ray beams in energy range from 5 to 30 MeV. The most appropriate way to irradiate a patient is determined during treatment planning. Currently, treatment planning system (TPS) is the main and the most important tool in the process of planning for radiotherapy. The main objective of this work is to develop a computational system based on the MC code Geant4 for dose evaluations in photon beam radiotherapy. In addition to treatment planning, these dose evaluations can be performed for research and quality control of equipment and TPSs. The computer system, called Quimera, consists of a graphical user interface (qGUI) and three MC applications (qLinacs, qMATphantoms and qNCTphantoms). The qGUI has the function of interface for the MC applications, by creating or editing the input files, running simulations and analyzing the results. The qLinacs is used for modeling and generation of Linac beams (phase space). The qMATphantoms and qNCTphantoms are used for dose calculations in virtual models of physical phantoms and computed tomography (CT) images, respectively. From manufacturer's data, models of a Varian Linac photon beam and a Varian multileaf collimator (MLC) were simulated in the qLinacs. The Linac and MLC modelling were validated using experimental data. qMATphamtoms and qNCTphantoms were validated using IAEA phase spaces. In this first version, the Quimera can be used for research, radiotherapy planning of simple treatments and quality control in photon beam radiotherapy. The MC applications work independent of the qGUI and the qGUI can be used for

  8. Influencia de las Emociones en el Proceso de Aprendizaje en Educación Inicial en Niños de 4 a 5 Años de Edad en el Centro de Estimulación Integral y Apoyo Psicoterapéutico de la Universidad del Azuay "CEIAP"

    OpenAIRE

    Zamora Torres, Johanna Elizabeth

    2013-01-01

    La presente investigación aborda la influencia de las emociones en el proceso de aprendizaje en educación inicial en niños de 4 a 5 años de edad, considerando que en esta etapa se desarrollan las diferentes áreas: cognitiva, motriz, lenguaje, social, afectiva, y el aspecto emocional indispensable para el correcto desenvolvimiento futuro del niño. Se abordará sobre la influencia de las emociones en el proceso enseñanza-aprendizaje ya que tradicionalmente ha existido una separación casi ab...

  9. Diagnostico ambiental integrado da area de influencia do descarte do material dragado do estuario de Santos

    OpenAIRE

    Luis Renato Bastos Lia

    2008-01-01

    Resumo: A Costa da Mata Atlântica é uma região do Estado de São Paulo com uma grande importância econômica, principalmente devido ao porto de Santos, o maior da América Latina e ao complexo industrial de Cubatão. O estuário da região foi impactado ao longo de anos pelas atividades antrópicas das indústrias, porto e da população residente nas vizinhanças do estuário. O objetivo deste trabalho consistiu no desenvolvimento e aplicação de uma metodologia integrada para um diagnóstico ambiental...

  10. GEANT4 simulation of a scintillating-fibre tracker for the cosmic-ray muon tomography of legacy nuclear waste containers

    Energy Technology Data Exchange (ETDEWEB)

    Clarkson, A.; Hamilton, D.J.; Hoek, M.; Ireland, D.G. [SUPA, School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8QQ, Scotland (United Kingdom); Johnstone, J.R. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG, England (United Kingdom); Kaiser, R.; Keri, T.; Lumsden, S. [SUPA, School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8QQ, Scotland (United Kingdom); Mahon, D.F., E-mail: David.Mahon@Glasgow.ac.uk [SUPA, School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8QQ, Scotland (United Kingdom); McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S. [SUPA, School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8QQ, Scotland (United Kingdom); Shearer, C.; Staines, C. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG, England (United Kingdom); Yang, G. [SUPA, School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8QQ, Scotland (United Kingdom); Zimmerman, C. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG, England (United Kingdom)

    2014-05-11

    Cosmic-ray muons are highly penetrative charged particles that are observed at the sea level with a flux of approximately one per square centimetre per minute. They interact with matter primarily through Coulomb scattering, which is exploited in the field of muon tomography to image shielded objects in a wide range of applications. In this paper, simulation studies are presented that assess the feasibility of a scintillating-fibre tracker system for use in the identification and characterisation of nuclear materials stored within industrial legacy waste containers. A system consisting of a pair of tracking modules above and a pair below the volume to be assayed is simulated within the GEANT4 framework using a range of potential fibre pitches and module separations. Each module comprises two orthogonal planes of fibres that allow the reconstruction of the initial and Coulomb-scattered muon trajectories. A likelihood-based image reconstruction algorithm has been developed that allows the container content to be determined with respect to the scattering density λ, a parameter which is related to the atomic number Z of the scattering material. Images reconstructed from this simulation are presented for a range of anticipated scenarios that highlight the expected image resolution and the potential of this system for the identification of high-Z materials within a shielded, concrete-filled container. First results from a constructed prototype system are presented in comparison with those from a detailed simulation. Excellent agreement between experimental data and simulation is observed showing clear discrimination between the different materials assayed throughout.

  11. GEANT4 simulation of a scintillating-fibre tracker for the cosmic-ray muon tomography of legacy nuclear waste containers

    Science.gov (United States)

    Clarkson, A.; Hamilton, D. J.; Hoek, M.; Ireland, D. G.; Johnstone, J. R.; Kaiser, R.; Keri, T.; Lumsden, S.; Mahon, D. F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Shearer, C.; Staines, C.; Yang, G.; Zimmerman, C.

    2014-05-01

    Cosmic-ray muons are highly penetrative charged particles that are observed at the sea level with a flux of approximately one per square centimetre per minute. They interact with matter primarily through Coulomb scattering, which is exploited in the field of muon tomography to image shielded objects in a wide range of applications. In this paper, simulation studies are presented that assess the feasibility of a scintillating-fibre tracker system for use in the identification and characterisation of nuclear materials stored within industrial legacy waste containers. A system consisting of a pair of tracking modules above and a pair below the volume to be assayed is simulated within the GEANT4 framework using a range of potential fibre pitches and module separations. Each module comprises two orthogonal planes of fibres that allow the reconstruction of the initial and Coulomb-scattered muon trajectories. A likelihood-based image reconstruction algorithm has been developed that allows the container content to be determined with respect to the scattering density λ, a parameter which is related to the atomic number Z of the scattering material. Images reconstructed from this simulation are presented for a range of anticipated scenarios that highlight the expected image resolution and the potential of this system for the identification of high-Z materials within a shielded, concrete-filled container. First results from a constructed prototype system are presented in comparison with those from a detailed simulation. Excellent agreement between experimental data and simulation is observed showing clear discrimination between the different materials assayed throughout.

  12. Detector Simulations with DD4hep

    Science.gov (United States)

    Petrič, M.; Frank, M.; Gaede, F.; Lu, S.; Nikiforou, N.; Sailer, A.

    2017-10-01

    Detector description is a key component of detector design studies, test beam analyses, and most of particle physics experiments that require the simulation of more and more different detector geometries and event types. This paper describes DD4hep, which is an easy-to-use yet flexible and powerful detector description framework that can be used for detector simulation and also extended to specific needs for a particular working environment. Linear collider detector concepts ILD, SiD and CLICdp as well as detector development collaborations CALICE and FCal have chosen to adopt the DD4hep geometry framework and its DDG4 pathway to Geant4 as its core simulation and reconstruction tools. The DDG4 plugins suite includes a wide variety of input formats, provides access to the Geant4 particle gun or general particles source and allows for handling of Monte Carlo truth information, eg. by linking hits and the primary particle that caused them, which is indispensable for performance and efficiency studies. An extendable array of segmentations and sensitive detectors allows the simulation of a wide variety of detector technologies. This paper shows how DD4hep allows to perform complex Geant4 detector simulations without compiling a single line of additional code by providing a palette of sub-detector components that can be combined and configured via compact XML files. Simulation is controlled either completely via the command line or via simple Python steering files interpreted by a Python executable. It also discusses how additional plugins and extensions can be created to increase the functionality.

  13. A FORMAÇÃO REFERENCIAL DO COMPORTAMENTO ORGANIZACIONAL NO ENFOQUE DA GESTÃO ARQUIVÍSTICA

    Directory of Open Access Journals (Sweden)

    Rosangela Formentini Caldas

    2012-06-01

    Full Text Available A aplicabilidade das teorias administrativas explica o processo de mudança e adaptação das unidades informacionais e refletem a influencia que o ambiente exerce sobre as organizações. O foco em estudos que otimizam os recursos institucionais, promovem uma compreensão da área da CI determinando sua essencial função na sociedade do conhecimento. O ambiente organizacional sofre influencias diretas do processo administrativo do trabalho e a solução de conflitos promove o êxito das organizações. No departamento de arquivo, o fator dos grupos informais determinados na teoria das relações humanas, exerce uma forte influência na gestão local. A pesquisa propôs verificar as influências social e científica da teoria das relações humanas para o processo de gestão de arquivos e para tanto se utilizou o estudo de caso de um arquivo pertencente a uma instituição universitária. A ferramenta estratégica de recolha de dados foi o Grupo Focal. A análise dos dados guiou-se por três fases distintas: Elementos motivacionais; influência comportamental no indivíduo e; integração da organização formal com a informal. Como resultados do estudo, a motivação e um bom ambiente de trabalho destacaram-se nos fatores que desenvolvem habilidades e competências dos funcionários, interferindo no comportamento organizacional que faz-se presente através de formas de recompensas, reconhecimento, homem social e grupos informais. Entende-se que pesquisas dessa natureza contribuem para o desenvolvimento da gestão de arquivos e sugere-se que os dados resultantes da análise sejam aplicados em arquivos com uma estrutura organizacional mais complexa, como no caso de arquivos públicos institucionais.

  14. A comparison of MCNP6-1.0 and GEANT 4-10.1 when evaluating the neutron output of a complex real world nuclear environment: The thermal neutron facility at the Tri Universities Meson facility

    Energy Technology Data Exchange (ETDEWEB)

    Monk, S.D., E-mail: s.monk@lancaster.ac.uk [Department of Engineering, Lancaster University, Lancaster LA1 4YW (United Kingdom); Shippen, B.A. [Department of Engineering, Lancaster University, Lancaster LA1 4YW (United Kingdom); Colling, B.R. [Department of Engineering, Lancaster University, Lancaster LA1 4YW (United Kingdom); Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Cheneler, D.; Al Hamrashdi, H.; Alton, T. [Department of Engineering, Lancaster University, Lancaster LA1 4YW (United Kingdom)

    2017-05-15

    Highlights: • Comparison of the use of MCNP6 and GEANT4 Monte Carlo software when large distances and thicknesses are considered. • The Thermal Neutron Facility (TNF) at TRIUMF used as an example real life example location. • The effects of water, aluminium, iron and lead considered over various thicknesses up to 3 m. - Abstract: A comparison of the Monte Carlo based simulation codes MCNP6-1.0 and GEANT4-10.1 as used for modelling large scale structures is presented here. The high-energy neutron field at the Tri Universities Meson Facility (TRIUMF) in Vancouver, British Columbia is the structure modelled in this work. Work with the emphasis on the modelling of the facility and comparing with experimental results has been published previously, whereas this work is focussed on comparing the performance of the codes over relatively high depths of material rather than the accuracy of the results themselves in comparison to experimental data. Comparisons of three different locations within the neutron facility are modelled and presented using both codes as well as analysis of the transport of typical neutrons fields through large blocks of iron, water, lead and aluminium in order to determine where any deviations are likely to have occurred. Results indicate that over short distances, results from the two codes are in broad agreement – although over greater distances and within more complex geometries, deviation increases dramatically. The conclusions reached are that it is likely the deviations between the codes is caused by both the compounding effect of slight differences between the cross section files used by the two codes to determine the neutron transport through iron, and differences in the processes used by both codes.

  15. Benchmarking and validation of a Geant4-SHADOW Monte Carlo simulation for dose calculations in microbeam radiation therapy.

    Science.gov (United States)

    Cornelius, Iwan; Guatelli, Susanna; Fournier, Pauline; Crosbie, Jeffrey C; Sanchez Del Rio, Manuel; Bräuer-Krisch, Elke; Rosenfeld, Anatoly; Lerch, Michael

    2014-05-01

    Microbeam radiation therapy (MRT) is a synchrotron-based radiotherapy modality that uses high-intensity beams of spatially fractionated radiation to treat tumours. The rapid evolution of MRT towards clinical trials demands accurate treatment planning systems (TPS), as well as independent tools for the verification of TPS calculated dose distributions in order to ensure patient safety and treatment efficacy. Monte Carlo computer simulation represents the most accurate method of dose calculation in patient geometries and is best suited for the purpose of TPS verification. A Monte Carlo model of the ID17 biomedical beamline at the European Synchrotron Radiation Facility has been developed, including recent modifications, using the Geant4 Monte Carlo toolkit interfaced with the SHADOW X-ray optics and ray-tracing libraries. The code was benchmarked by simulating dose profiles in water-equivalent phantoms subject to irradiation by broad-beam (without spatial fractionation) and microbeam (with spatial fractionation) fields, and comparing against those calculated with a previous model of the beamline developed using the PENELOPE code. Validation against additional experimental dose profiles in water-equivalent phantoms subject to broad-beam irradiation was also performed. Good agreement between codes was observed, with the exception of out-of-field doses and toward the field edge for larger field sizes. Microbeam results showed good agreement between both codes and experimental results within uncertainties. Results of the experimental validation showed agreement for different beamline configurations. The asymmetry in the out-of-field dose profiles due to polarization effects was also investigated, yielding important information for the treatment planning process in MRT. This work represents an important step in the development of a Monte Carlo-based independent verification tool for treatment planning in MRT.

  16. The study of the particle trajectories in the magnetic fields of MARUSYA setup using GEANT 3 package

    International Nuclear Information System (INIS)

    Argintaru, Danut; Besliu, Calin; Jipa, Alexandru; Esanu, Tiberiu; Calin, Marius; Argintaru, Cristina

    2005-01-01

    Using the GEANT 3 package we simulate the trajectories of the detected particles in the MARUSYA (JINR Dubna) setup. The dependence between the particle momenta and TOF, dE/dx, velocities and angles are important both for the detectors design and particle identification (PID). (authors)

  17. Regulación de las metalotioneínas durante el estrés y la inflamación, y su influencia durante la respuesta inflamatoria

    OpenAIRE

    Carrasco Trancoso, Javier

    2000-01-01

    Regulación de las metalotioneínas durante el estrés y la inflamación, y su influencia durante la respuesta inflamatoria. Las metalotioneínas (MTs) son unas proteínas de bajo peso molecular (6-7 kDa) con capacidad para ligar metales pesados como el Zn y el Cu. En los roedores existen cuatro isoformas diferentes denominadas MT-I, -II, -III y IV. Las MT-I y MT-II se expresan prácticamente en todos los tejidos del organismo y son inducibles por metales pesados, agentes oxidantes, hormonas, la inf...

  18. A influência da comunicação não verbal no cuidado de enfermagem La influencia de la comunicación no verbal en la atención de enfermería The influence of non-verbal communication in nursing care

    Directory of Open Access Journals (Sweden)

    Carla Cristina Viana Santos

    2005-08-01

    Full Text Available Este estudo é vinculado ao Núcleo de Pesquisa e Experimentação em Enfermagem da Escola de Enfermagem Alfredo Pinto UNIRIO, e que teve origem durante o desenvolvimento de um trabalho monográfico. O objeto constitui-se no significado da comunicação não-verbal sob a ótica dos graduandos de enfermagem. Apresenta como objetivos: Identificar o significado da comunicação não verbal para os acadêmicos de enfermagem e Analisar a influência da mesma no cuidado de enfermagem. A abordagem metodológica utilizada foi à qualitativa aplicando-se como estratégia a dinâmica de sensibilidade para a coleta de dados. Observa-se que os alunos da graduação identificam a importância e a influência da comunicação não verbal durante a assistência, entretanto, há a necessidade em se ampliar o conhecimento do processo de comunicação não verbal para implementação do cuidado de enfermagem.Este estudio está vinculado al Núcleo de Investigación y Experimentación en Enfermería de la Escuela de Enfermería Alfredo Pinto UNIRIO, y que tuvo origen durante el desarrollo de un trabajo de monografía. El objeto se constituye en el significado de la comunicación no-verbal según la visión de los estudiantes de graduación en enfermería. Presenta como objetivos: Identificar el significado de la comunicación no-verbal para los académicos de enfermería, y Analizar la influencia de la misma en el cuidado de enfermería. El enfoque metodológico utilizado fue el cualitativo, y se aplicó la dinámica de sensibilidad como estrategia para la recopilación de datos. Se observa que los alumnos del curso de graduación identifican la importancia y la influencia de la comunicación no-verbal durante la asistencia, sin embargo, existe la necesidad de ampliar el conocimiento del proceso de comunicación no-verbal para la implementación del cuidado de enfermería.The present study is linked to the Center for Researching and Testing in Nursing at the

  19. La influencia de la convivencia escolar en el nivel de inclusión educativa, en estudiantes de bachiller

    Directory of Open Access Journals (Sweden)

    MSc. Rolando Medina Peña

    2016-04-01

    Full Text Available La inclusión educativa muchas veces no es bien entendida y se interpreta de diversas formas en el mundo. Desde el campo educativo se connota, a la manera en que la ins­titución educacional da respuesta a la diversidad y, tiene relación directa con el término necesidades educativas es­peciales (NEE. La investigación examina la influencia del código de convivencia escolar en el nivel de inclusión edu­cativa, a partir de la asunción de las necesidades educati­vas especiales de algunos de sus estudiantes. Se perfec­ciona la comprensión de las NEE, de inclusión educativa y los recursos educativos que se ajustan a las peculiaridades del desarrollo humano.

  20. UMA DISCUSSÃO SOBRE A NATUREZA CONTINGENTE E O CRITÉRIO DE RECONHECIMENTO DA DÍVIDA ATIVA DA UNIÃO

    Directory of Open Access Journals (Sweden)

    Paterson da Rocha Severo

    2016-12-01

    Full Text Available A dívida ativa é um crédito decorrente de receitas públicas não recebidas no prazo estabelecido, registrado nas contas públicas após a apuração de sua liquidez e certeza por autoridade administrativa competente. Considerando que dado seu elevado montante o reconhecimento da Dívida Ativa da União (DAU influencia a análise do Balanço Geral da União (BGU, e que o processo de convergência no Setor Público requer a adoção de padrões contábeis fundamentados na Teoria Contábil, o presente estudo tem como objetivo apresentar uma discussão sobre a natureza contingente e o critério de reconhecimento da DAU. Assim, foram levantados dados do período de 2008 a 2013 no Sistema Integrado de Administração Financeira do Governo Federal (SIAFI e no Sistema Integrado da Dívida Ativa da Procuradoria-Geral da Fazenda Nacional (DW Sida, para análise do perfil dos créditos inscritos. Os resultados do estudo mostram que em sua maior parte os valores registrados em DAU apresenta incertezas quanto à sua validade e real possibilidade de recebimento, caracterizando-se, portanto, como ativo contingente. Assim, a DAU deve ser reconhecida no BGU apenas quando benefícios econômicos ou potenciais futuros forem considerados praticamente certos pelos órgãos responsáveis por sua gestão.

  1. Detailed GEANT description of the SDC central calorimeters

    International Nuclear Information System (INIS)

    Glagolev, V.V.; Li, W.

    1994-01-01

    This article represents the very detailed simulation model of the SDC central calorimeters and some results which were obtained using that model. The central calorimeters structure was coded on the GEANT 3.15 base in the frame of the SDCSIM environment. The SDCSIM is the general shell for simulation of the SDC set-up. The calorimeters geometry has been coded according to the FNAL and ANL engineering drawings and engineering data file. SDC central calorimeters detailed description is extremely useful for different simulation tasks, for fast simulation program parameters tuning, for different geometry especially studying (local response nonuniformity from bulkheads in the e.m. calorimeter and from coil supports and many others) and for the interpretation of the experimental data from the calorimeters. This simulation model is very useful for tasks of the test beam modules calorimeter calibration and for calorimeter in situ calibration. 3 refs., 8 figs

  2. Influencia de la densidad y del confinamiento con geotextil en columnas de grava

    OpenAIRE

    Miranda Manzanares, Marina

    2014-01-01

    RESUMEN: El tratamiento con columnas de grava es uno de los métodos de mejora del terreno empleados habitualmente para la cimentación de terraplenes o estructuras sobre suelos blandos. El estudio realizado en esta Tesis Doctoral se centra en analizar: - La influencia de la densidad de la grava de la columna - El empleo de columnas ensacadas con geotextil. El análisis de la influencia de la densidad de la grava se ha realizado mediante ensayos realizados en laboratorio en modelo reducido con d...

  3. Influencia de la densidad y del confinamiento con geotextil en columnas de grava

    OpenAIRE

    Miranda Manzanares, Marina

    2014-01-01

    El tratamiento con columnas de grava es uno de los métodos de mejora del terreno empleados habitualmente para la cimentación de terraplenes o estructuras sobre suelos blandos. El estudio realizado en esta Tesis Doctoral se centra en analizar: - La influencia de la densidad de la grava de la columna - El empleo de columnas ensacadas con geotextil. El análisis de la influencia de la densidad de la grava se ha realizado mediante ensayos realizados en laboratorio en modelo reducido con dos densid...

  4. GEANT4 simulation of the neutron background of the C{sub 6}D{sub 6} set-up for capture studies at n{sub T}OF

    Energy Technology Data Exchange (ETDEWEB)

    Žugec, P., E-mail: pzugec@phy.hr [Department of Physics, Faculty of Science, University of Zagreb (Croatia); Colonna, N. [Istituto Nazionale di Fisica Nucleare, Bari (Italy); Bosnar, D. [Department of Physics, Faculty of Science, University of Zagreb (Croatia); Altstadt, S. [Johann-Wolfgang-Goethe Universität, Frankfurt (Germany); Andrzejewski, J. [Uniwersytet Łódzki, Lodz (Poland); Audouin, L. [Centre National de la Recherche Scientifique/IN2P3 – IPN, Orsay (France); Barbagallo, M. [Istituto Nazionale di Fisica Nucleare, Bari (Italy); Bécares, V. [Centro de Investigaciones Energeticas Medioambientales y Tecnológicas (CIEMAT), Madrid (Spain); Bečvář, F. [Charles University, Prague (Czech Republic); Belloni, F. [Commissariat à l' Énergie Atomique (CEA) Saclay – Irfu, Gif-sur-Yvette (France); Berthoumieux, E. [Commissariat à l' Énergie Atomique (CEA) Saclay – Irfu, Gif-sur-Yvette (France); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Billowes, J. [University of Manchester, Oxford Road, Manchester (United Kingdom); Boccone, V.; Brugger, M.; Calviani, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Calviño, F. [Universitat Politecnica de Catalunya, Barcelona (Spain); Cano-Ott, D. [Centro de Investigaciones Energeticas Medioambientales y Tecnológicas (CIEMAT), Madrid (Spain); Carrapiço, C. [Instituto Tecnológico e Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, Lisboa (Portugal); Cerutti, F. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); and others

    2014-10-01

    The neutron sensitivity of the C{sub 6}D{sub 6} detector setup used at n{sub T}OF facility for capture measurements has been studied by means of detailed GEANT4 simulations. A realistic software replica of the entire n{sub T}OF experimental hall, including the neutron beam line, sample, detector supports and the walls of the experimental area has been implemented in the simulations. The simulations have been analyzed in the same manner as experimental data, in particular by applying the Pulse Height Weighting Technique. The simulations have been validated against a measurement of the neutron background performed with a {sup nat}C sample, showing an excellent agreement above 1 keV. At lower energies, an additional component in the measured {sup nat}C yield has been discovered, which prevents the use of {sup nat}C data for neutron background estimates at neutron energies below a few hundred eV. The origin and time structure of the neutron background have been derived from the simulations. Examples of the neutron background for two different samples are demonstrating the important role of accurate simulations of the neutron background in capture cross-section measurements.

  5. Geant4 simulation of clinical proton and carbon ion beams for the treatment of ocular melanomas with the full 3-D pencil beam scanning system

    Energy Technology Data Exchange (ETDEWEB)

    Farina, Edoardo; Riccardi, Cristina; Rimoldi, Adele; Tamborini, Aurora [University of Pavia and the INFN section of Pavia, via Bassi 6, 27100 Pavia (Italy); Piersimoni, Pierluigi [Division of Radiation Research, Loma Linda University, Loma Linda, CA 92354 (United States); Ciocca, Mario [Medical Physics Unit, CNAO Foundation, Strada Campeggi 53, 27100 Pavia (Italy)

    2015-07-01

    This work investigates the possibility to use carbon ion beams delivered with active scanning modality, for the treatment of ocular melanomas at the Centro Nazionale di Adroterapia Oncologica (CNAO) in Pavia. The radiotherapy with carbon ions offers many advantages with respect to the radiotherapy with protons or photons, such as a higher relative radio-biological effectiveness (RBE) and a dose release better localized to the tumor. The Monte Carlo (MC) Geant4 10.00 patch-03 toolkit is used to reproduce the complete CNAO extraction beam line, including all the active and passive components characterizing it. The simulation of proton and carbon ion beams and radiation scanned field is validated against CNAO experimental data. For the irradiation study of the ocular melanoma an eye-detector, representing a model of a human eye, is implemented in the simulation. Each element of the eye is reproduced with its chemical and physical properties. Inside the eye-detector a realistic tumor volume is placed and used as the irradiation target. A comparison between protons and carbon ions eye irradiations allows to study possible treatment benefits if carbon ions are used instead of protons. (authors)

  6. Modeling of very low frequency (VLF radio wave signal profile due to solar flares using the GEANT4 Monte Carlo simulation coupled with ionospheric chemistry

    Directory of Open Access Journals (Sweden)

    S. Palit

    2013-09-01

    Full Text Available X-ray photons emitted during solar flares cause ionization in the lower ionosphere (~60 to 100 km in excess of what is expected to occur due to a quiet sun. Very low frequency (VLF radio wave signals reflected from the D-region of the ionosphere are affected by this excess ionization. In this paper, we reproduce the deviation in VLF signal strength during solar flares by numerical modeling. We use GEANT4 Monte Carlo simulation code to compute the rate of ionization due to a M-class flare and a X-class flare. The output of the simulation is then used in a simplified ionospheric chemistry model to calculate the time variation of electron density at different altitudes in the D-region of the ionosphere. The resulting electron density variation profile is then self-consistently used in the LWPC code to obtain the time variation of the change in VLF signal. We did the modeling of the VLF signal along the NWC (Australia to IERC/ICSP (India propagation path and compared the results with observations. The agreement is found to be very satisfactory.

  7. Benchmarking the Geant4 full system simulation of an associated alpha-particle detector for use in a D-T neutron generator.

    Science.gov (United States)

    Zhang, Xiaodong; Hayward, Jason P; Cates, Joshua W; Hausladen, Paul A; Laubach, Mitchell A; Sparger, Johnathan E; Donnald, Samuel B

    2012-08-01

    The position-sensitive alpha-particle detector used to provide the starting time and initial direction of D-T neutrons in a fast-neutron imaging system was simulated with a Geant4-based Monte Carlo program. The whole detector system, which consists of a YAP:Ce scintillator, a fiber-optic faceplate, a light guide, and a position-sensitive photo-multiplier tube (PSPMT), was modeled, starting with incident D-T alphas. The scintillation photons, whose starting time follows the distribution of a scintillation decay curve, were produced and emitted uniformly into a solid angle of 4π along the track segments of the alpha and its secondaries. Through tracking all photons and taking into account the quantum efficiency of the photocathode, the number of photoelectrons and their time and position distributions were obtained. Using a four-corner data reconstruction formula, the flood images of the alpha detector with and without optical grease between the YAP scintillator and the fiber-optic faceplate were obtained, which show agreement with the experimental results. The reconstructed position uncertainties of incident alpha particles for both cases are 1.198 mm and 0.998 mm respectively across the sensitive area of the detector. Simulation results also show that comparing with other faceplates composed of 500 μm, 300 μm, and 100 μm fibers, the 10-μm-fiber faceplate is the best choice to build the detector for better position performance. In addition, the study of the background originating inside the D-T generator suggests that for 500-μm-thick YAP:Ce coated with 1-μm-thick aluminum, and very good signal-to-noise ratio can be expected through application of a simple threshold. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. A Influencia dos roedores e aves na regeneraçao da Araucaria angustifolia (Bert.)O. Ktze

    OpenAIRE

    Müller, Jorge Alberto

    2013-01-01

    Este trabalho foi desenvolvido na Reserva Experimental do Setor de Ciências Agrárias, da Universidade Federal do Paraná, em São João do Triunfo a 130 quilômetros de Curitiba durante os anos de 19 81 e 19 82 em uma área de mata nativa, cujas árvores predominantes são araucárias. Os experimentos foram complementados por testes realizados no laboratório e no viveiro florestal do Curso de Engenharia Florestal. Visando incrementar a regeneração da araucária através da proteção de suas sementes- pi...

  9. A Geant4-based Simulation to Evaluate the Feasibility of Using Nuclear Resonance Fluorescence (NRF) in Determining Atomic Compositions of Body Tissue in Cancer Diagnostics and Irradiation

    Science.gov (United States)

    Gilbo, Yekaterina; Wijesooriya, Krishni; Liyanage, Nilanga

    2017-01-01

    Customarily applied in homeland security for identifying concealed explosives and chemical weapons, NRF (Nuclear Resonance Fluorescence) may have high potential in determining atomic compositions of body tissue. High energy photons incident on a target excite the target nuclei causing characteristic re-emission of resonance photons. As the nuclei of each isotope have well-defined excitation energies, NRF uniquely indicates the isotopic content of the target. NRF radiation corresponding to nuclear isotopes present in the human body is emitted during radiotherapy based on Bremsstrahlung photons generated in a linear electron accelerator. We have developed a Geant4 simulation in order to help assess NRF capabilities in detecting, mapping, and characterizing tumors. We have imported a digital phantom into the simulation using anatomical data linked to known chemical compositions of various tissues. Work is ongoing to implement the University of Virginia's cancer center treatment setup and patient geometry, and to collect and analyze the simulation's physics quantities to evaluate the potential of NRF for medical imaging applications. Preliminary results will be presented.

  10. The effect of 111In radionuclide distance and auger electron energy on direct induction of DNA double-strand breaks: a Monte Carlo study using Geant4 toolkit.

    Science.gov (United States)

    Piroozfar, Behnaz; Raisali, Gholamreza; Alirezapour, Behrouz; Mirzaii, Mohammad

    2018-04-01

    In this study, the effect of 111 In position and Auger electron energy on direct induction of DSBs was investigated. The Geant4-DNA simulation toolkit was applied using a simple B-DNA form extracted from PDBlib library. First, the simulation was performed for electrons with energies of 111 In and equal emission probabilities to find the most effective electron energies. Then, 111 In Auger electrons' actual spectrum was considered and their contribution in DSB induction analysed. The results showed that the most effective electron energy is 183 eV, but due to the higher emission probability of 350 eV electrons, most of the DSBs were induced by the latter electrons. Also, it was observed that most of the DSBs are induced by electrons emitted within 4 nm of the central axis of the DNA and were mainly due to breaks with <4 base pairs distance in opposing strands. Whilst, when 111 In atoms are very close to the DNA, 1.3 DSBs have been obtained per decay of 111 In atoms. The results show that the most effective Auger electrons are the 350 eV electrons from 111 In atoms with <4 nm distance from the central axis of the DNA which induce ∼1.3 DSBs per decay when bound to the DNA. This value seems reasonable when compared with the reported experimental data.

  11. Enriquecimento da dieta do bicho-da-seda com extrato hidrossolúvel de soja Enrichment of the silkworms diet with soybean water soluble extract

    Directory of Open Access Journals (Sweden)

    Gustavo do Valle Polycarpo

    2012-09-01

    Full Text Available O objetivo deste trabalho foi avaliar se a suplementação da dieta do bicho-da-seda com extrato hidrossolúvel de soja (EHS interfere na produção de casulos e no consumo de folhas de amoreira (Morus alba L. de diferentes cultivares pelas lagartas. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 4x5, com quatro cultivares de amoreira ('IZ64', 'IZ56/4', 'FM86' e 'FMSM' e cinco dietas (folhas não tratadas, folhas umedecidas com água, folhas enriquecidas com EHS, em três níveis: suplementação da dieta com 5, 10 e 20% de PB. O EHS foi aspergido sobre as folhas, tendo a água como agente dispersante. O consumo foi verificado pela diferença entre a quantidade de folhas fornecidas e a quantidade não consumida pelas lagartas. A ingestão de alimento apresentou-se de forma quadrática, diminuindo à medida que o EHS foi adicionado à dieta. Houve interação dos fatores cultivar e dieta. O fornecimento de folhas de amoreira com acréscimo proteico de 10% por meio do EHS melhorou a qualidade dos casulos do bicho-da-seda com a utilização das cultivares 'IZ56/4' e 'FMSM'. A pulverização de EHS nas folhas da cultivar 'IZ64' prejudicou a produção de casulos. Lagartas do bicho-da-seda, alimentadas com folhas de amoreira sem suplementação, produziram cascas séricas mais pesadas com folhas das cultivares 'IZ64' e 'FMSM'. A aspersão de água nas folhas incrementou o peso de cascas séricas produzidas a partir da cultivar 'FM86'. A suplementação da dieta com EHS diminui o consumo da lagarta do bicho-da-seda. A aplicação de EHS influencia a produção de casulos em função da cultivar utilizada.The aim of this research was to assess if the supplementation of the silkworm diet with soybean water soluble extract (WSE interferes on the consumption of mulberry leaves (Morus alba L. by the caterpillars and on cocoon production. The experimental design was completely randomized in factorial arrangement 4x5

  12. Corpo e religião: marcas da educação evangélica no corpo feminino

    Directory of Open Access Journals (Sweden)

    Ana Carolina Capellini Rigoni

    2013-03-01

    Full Text Available Este estudo teve como objetivo compreender a forma como a Igreja Evangélica Assembleia de Deus influencia na educação do corpo das meninas que a frequentam. O estudo teve como base o referencial teórico da Sociologia e da Antropologia, constituindo-se como uma etnografia, realizada em um templo da Assembleia de Deus na cidade de Campinas/SP, entre março de 2006 a dezembro de 2007. A partir deste estudo percebemos o modo como a educação religiosa recebida pelas meninas gera implicações na educação do corpo das mesmas, que estabelecem uma espécie de negociação entre os costumes postulados pela Igreja e outras formas de educação.

  13. Detector simulations with DD4hep

    CERN Document Server

    AUTHOR|(SzGeCERN)668365; Frank, Markus; Gaede, Frank-Dieter; Lu, Shaojun; Nikiforou, Nikiforos; Sailer, Andre

    2017-01-01

    Detector description is a key component of detector design studies, test beam analyses, and most of particle physics experiments that require the simulation of more and more different detector geometries and event types. This paper describes DD4hep, which is an easy-to-use yet flexible and powerful detector description framework that can be used for detector simulation and also extended to specific needs for a particular working environment. Linear collider detector concepts ILD, SiD and CLICdp as well as detector development collaborations CALICE and FCal have chosen to adopt the DD4hep geometry framework and its DDG4 pathway to Geant4 as its core simulation and reconstruction tools. The DDG4 plugins suite includes a wide variety of input formats, provides access to the Geant4 particle gun or general particles source and allows for handling of Monte Carlo truth information, e.g. by linking hits and the primary particle that caused them, which is indispensable for performance and efficiency studies. An extend...

  14. Lateral variations of radiobiological properties of therapeutic fields of 1H, 4He, 12C and 16O ions studied with Geant4 and microdosimetric kinetic model

    Science.gov (United States)

    Dewey, Sophie; Burigo, Lucas; Pshenichnov, Igor; Mishustin, Igor; Bleicher, Marcus

    2017-07-01

    As known, in cancer therapy with ion beams the relative biological effectiveness (RBE) of ions changes in the course of their propagation in tissues. Such changes are caused not only by increasing the linear energy transfer (LET) of beam particles with the penetration depth towards the Bragg peak, but also by nuclear reactions induced by beam nuclei leading to the production of various secondary particles. Although the changes of RBE along the beam axis have been studied quite well, much less attention has been paid to the evolution of RBE in the transverse direction, perpendicular to the beam axis. In order to fill this gap, we simulated radiation fields of 1H, 4He, 12C and 16O nuclei of 20 mm in diameter by means of a Geant4-based Monte Carlo model for heavy-ion therapy connected with the modified microdosimetric kinetic model to describe the response of normal ((α/β)_x-rays=3.8 Gy) and early-responding ((α/β)_x-rays=10 Gy) tissues. Depth and radial distributions of saturation-corrected dose-mean lineal energy, RBE and RBE-weighted dose are investigated for passive beam shaping and active beam scanning. The field of 4He has a small lateral spread as compared with 1H field, and it is characterised by a modest lateral variation of RBE suggesting the use of fixed RBE values across the field transverse cross section at each depth. Reduced uncertainties of RBE on the boundary of a 4He treatment field can be advantageous in a specific case of an organ at risk located in lateral proximity to the target volume. It is found that the lateral distributions of RBE calculated for 12C and 16O fields demonstrate fast variations in the radial direction due to changes of dose and composition of secondary fragments in the field penumbra. Nevertheless, the radiation fields of all four projectiles at radii larger than 20 mm can be characterized by a common RBE value defined by tissue radiosensitivity. These findings can help, in particular, in accessing the transverse

  15. Análise da distribuição espacial de dose absorvida em próton terapia ocular Spatial distribution analysis of absorbed dose in ocular proton radiation therapy

    Directory of Open Access Journals (Sweden)

    Marília Tavares Christóvão

    2010-08-01

    Full Text Available OBJETIVO: Propõe-se avaliar os perfis de dose em profundidade e as distribuições espaciais de dose para protocolos de radioterapia ocular por prótons, a partir de simulações computacionais em código nuclear e modelo de olho discretizado em voxels. MATERIAIS E MÉTODOS: As ferramentas computacionais empregadas foram o código Geant4 (GEometry ANd Tracking Toolkit e o SISCODES (Sistema Computacional para Dosimetria em Radioterapia. O Geant4 é um pacote de software livre, utilizado para simular a passagem de partículas nucleares com carga elétrica através da matéria, pelo método de Monte Carlo. Foram executadas simulações computacionais reprodutivas de radioterapia por próton baseada em instalações pré-existentes. RESULTADOS: Os dados das simulações foram integrados ao modelo de olho através do código SISCODES, para geração das distribuições espaciais de doses. Perfis de dose em profundidade reproduzindo o pico de Bragg puro e modulado são apresentados. Importantes aspectos do planejamento radioterápico com prótons são abordados, como material absorvedor, modulação, dimensões do colimador, energia incidente do próton e produção de isodoses. CONCLUSÃO: Conclui-se que a terapia por prótons, quando adequadamente modulada e direcionada, pode reproduzir condições ideais de deposição de dose em neoplasias oculares.OBJECTIVE: The present study proposes the evaluation of the depth-dose profiles and the spatial distribution of radiation dose for ocular proton beam radiotherapy protocols, based on computer simulations in nuclear codes and an eye model discretized into voxels. MATERIALS AND METHODS: The employed computational tools were Geant4 (GEometry ANd Tracking Toolkit and SISCODES (Sistema Computacional para Dosimetria em Radioterapia - Computer System for Dosimetry in Radiotherapy. Geant4 is a toolkit for simulating the passage of particles through the matter, based on Monte Carlo method. Computer simulations

  16. Música y cerebro: influencia del arte musical en la biología humana

    OpenAIRE

    Siesto Sánchez, Violeta

    2017-01-01

    Trabajo de fin de grado. Grado en Biología. Curso académico 2016-2017 El trabajo analiza la posible influencia de la música en el desarrollo de las habilidades humanas. Se analiza la anatomía humana relacionada en el proceso, desde el sistema auditivo hasta la corteza cerebral. La segunda parte del estudio lo pone en relación con el proceso de percepción y se refiere a la relaciónd el hombre con la música a lo largo de la historia, con particular atención a la influencia que pueda haber t...

  17. Impacto da Conversão da Cobertura Natural em Pastagem e Área Urbana sobre Variáveis Biofísicas no Sul do Amazonas

    Directory of Open Access Journals (Sweden)

    Vagner Marques Pavão

    Full Text Available Resumo A substituição da cobertura natural por áreas de pastagem afeta o albedo superficial, que por sua vez influencia no saldo de radiação e na temperatura superficial. Assim, o objetivo desse trabalho foi avaliar os impactos do desmatamento sobre variáveis biofísicas no município de Apuí-AM, por imagens Landsat 5 TM (Thematic Mapper. As imagens utilizadas nesse estudo foram fornecidas pelo Serviço Geológico dos Estados Unidos (USGS. A imagem de 20/07/2010 foi processada por etapas intermediárias do SEBAL (Surface Energy Balance Algorithm for Land. O desmatamento no município de Apuí aumentou em 20% nos últimos 20 anos analisados. O NDVI da Floresta foi 20 e 43% maior que da pastagem e da área urbana, respectivamente. O albedo da superfície na pastagem e na área urbana foram 16% maiores que na área de Floresta e a temperatura de brilho da superfície na pastagem e na área urbana foram 16 e 10% maiores que na área de Floresta, respectivamente. O Rn na área de Floresta foi 8% e 6% maior que na área urbana e na pastagem, respectivamente. Portanto, a conversão da Floresta Amazônica modifica o balanço de radiação com maior disponibilidade de calor sensível da superfície nas áreas de pastagem e urbana.

  18. INFLUENCIA DEL TEMPO DE LA MÚSICA EN LAS EMOCIONES

    Directory of Open Access Journals (Sweden)

    Jonathan Azael Caballero-Meneses

    2010-01-01

    Full Text Available Se sabe que la música puede influir en dos componentes de lasemociones: el arousal y la valencia. En particular, se ha reportadoque el tempo o rapidez de la música está directamenterelacionado con el arousal, aunque su relación con la valenciao medida de afecto no es aún clara. En este trabajo se analizóla influencia del tempo en ambos componentes mediante laexposición de 24 estudiantes de licenciatura a treinta extractosmusicales de distinto tempo. Además se evaluó la posiblemodulación de la relación tempo-valencia por el rasgo de personalidadextroversión/introversión. Los resultados confirmaronla influencia del tempo sobre el arousal, pero no sobrela valencia, así como una posible mediación de la dimensiónde personalidad introversión-extroversión sobre la valencia.

  19. Avaliação agroeconômica das culturas da beterraba e coentro em função da época de estabelecimento do consórcio

    OpenAIRE

    Grangeiro,Leilson Costa; Santos,Allysson Pereira; Freitas,Francisco Claúdio Lopes; Simão,Livia Maciel Costa; Bezerra Neto,Francisco

    2011-01-01

    A consorciação de culturas é uma prática de cultivo usada na produção de hortaliças, e que influencia sobremaneira a produtividade dessas culturas, além de gerar vários benefícios agroeconômicos. O objetivo do presente trabalho foi avaliar os rendimentos de beterraba (Beta vulgarias L.) e coentro (Coriandrum sativum L.) em função da época de estabelecimento do consórcio entre essas culturas. O trabalho foi conduzido na Universidade Federal Rural do Semiárido, Mossoró-RN, durante o período de ...

  20. Auto-relato e relato de informante secundário na avaliação da saúde em idosos

    OpenAIRE

    Jardim, Renata; Barreto, Sandhi Maria; Giatti, Luana

    2010-01-01

    OBJETIVO: Analisar se o modelo explicativo para a avaliação da saúde do idoso com base no auto-relato é comparável com o modelo de relato do informante secundário e se a auto-avaliação de saúde do informante secundário influencia a avaliação da saúde do idoso. MÉTODOS: Estudo transversal com 230 pares idoso-informante secundário realizado em Belo Horizonte, MG, em 2007. Foram investigadas variáveis sociodemográficas e de saúde dos idosos por meio de entrevista estruturada. Utilizou-se regress...

  1. Efeito da cadência de pedalada sobre a arquitetura do músculo vasto lateral e o comprimento da unidade músculo-tendínea

    OpenAIRE

    Júlio Cezar Lima da Silva

    2016-01-01

    A cadência de pedalada é um importante componente na produção de potência, sendo responsável pelas mudanças na velocidade de encurtamento muscular, a qual influencia diretamente o desempenho no ciclismo. Ainda não está claro se a redução na ativação muscular e o menor torque no pedivela estão associados com a redução na contribuição dos tecidos ativos e/ou passivos em diferentes velocidades de pedalada. O objetivo da presente dissertação foi investigar o efeito de diferentes cadências de peda...

  2. Niilismo, Ressentimento e Patologia: A Filosofia de Schopenhauer como Sintoma da Decadência Cultural Europeia Segunda a Crítica de Friedrich Nietzsche

    Directory of Open Access Journals (Sweden)

    Eli Vagner Rodrigues

    2017-02-01

    Full Text Available Pretende-se neste artigo abordar o problema da relação entre o ressentimento e a formação dos juízos morais presentes na obra de Schopenhauer a partir de uma perspectiva crítica proposta por Nietzsche que tem suas bases na constatação de que existe na ética ocidental um enfraquecimento das posturas afirmativas da vida como resultado de uma decadência fisiopatológica que influencia a ordem dos juízos morais sobre a existência humana. A ética niilista de Schopenhauer seria um exemplo de uma desagregação dos instintos afirmativos vitais configurando-se por isso como uma moral da fraqueza e, consequentemente um sintoma da decadência cultural europeia.

  3. Application of the GEANT3 geometry package to the description of the OPAL detector

    Energy Technology Data Exchange (ETDEWEB)

    Allison, J; Brun, R; Bruyant, F; Zanarini, P; Bullock, F W; Hobson, P R; Chang, C Y; Dumont, J J; Hemingway, R J; McPherson, A C

    1987-10-01

    We present the general features of the GEANT3 package for coding the geometrical structure of a large and complex detector in the computer programs used for their design and analysis. This package has been developed in the context of Monte Carlo studies of detector performance but should be well matched to the problem of analysis. As a specific example, we illustrate the description of the OPAL detector for the Large Electron Positron collider at CERN and show the results of a sample study using this description.

  4. GEANT4 hadronic cascade models analysis of proton and charged pion transverse momentum spectra from p plus Cu and Pb collisions at 3, 8, and 15 GeV/c

    CERN Document Server

    Abdel-Waged, Khaled; Uzhinskii, V V

    2011-01-01

    We describe how various hadronic cascade models, which are implemented in the GEANT4 toolkit, describe proton and charged pion transverse momentum spectra from p + Cu and Pb collisions at 3, 8, and 15 GeV/c, recently measured in the hadron production (HARP) experiment at CERN. The Binary, ultrarelativistic quantum molecular dynamics (UrQMD) and modified FRITIOF (FTF) hadronic cascade models are chosen for investigation. The first two models are based on limited (Binary) and branched (UrQMD) binary scattering between cascade particles which can be either a baryon or meson, in the three-dimensional space of the nucleus, while the latter (FTF) considers collective interactions between nucleons only, on the plane of impact parameter. It is found that the slow (p(T) 0.3 GeV/c) proton spectra are not strongly affected by the differences between the FTF and UrQMD models. It is also shown that the UrQMD and FTF combined with Binary (FTFB) models could reproduce both proton and charged pion spectra from p + Cu and Pb...

  5. Analise da influencia das fontes de carbono na patogenicidade do Moniliophthora perniciosa pathogenicity em Theobroma cacao

    OpenAIRE

    Fatima Cerqueira Alvim

    2009-01-01

    Resumo: O fungo basidiomiceto hemibiotrófico Moniliophthora perniciosa, agente causal da doença vassoura-de-bruxa (VB) em Theobroma cacao, é o principal patógeno da lavoura cacaueira nas Américas e no Caribe. O presente trabalho apresentou como objetivo primordial identificar proteínas relacionadas com a patogenicidade deste fungo. No primeiro capítulo desta tese foi demonstrado o efeito de diferentes fontes de carbono sobre a morfologia e fisiologia do M, perniciosa. O fungo foi crescido em ...

  6. Estudo comparativo sobre representações visuais em interfaces com base em ícones de dispositivos móveis da Apple

    OpenAIRE

    Marshal Becon Lauzer

    2013-01-01

    Esta dissertação teve por objetivo verificar se existe um diferencial estético nas representações visuais nas interfaces gráficas dos dispositivos móveis da Apple e, se existir, se esse diferencial efetivamente influencia o vínculo do usuário com a marca e se o usuário tem consciência dele. Para tanto é apresentada uma breve análise diacrônica sobre as interfaces computacionais, bem como uma descrição de momentos chave na história da referida empresa. A partir disto, são abordadas questões qu...

  7. Influencia del tamaño del cristal de cinc de láminas de acero galvanizadas en ambientes que contienen cloruros y sulfatos

    Directory of Open Access Journals (Sweden)

    Julieth Andrea Ramírez-Jerez

    2015-05-01

    Full Text Available El trabajo evaluó la influencia del tamaño del cristal de cinc en el comportamiento electroquímico de láminas de acero galvanizadas por inmersión en caliente. Los ensayos se realizaron en una celda electroquímica plana en soluciones con diferentes concentraciones de NaCl y NaSO4. La velocidad y el mecanismo de corrosión, así como las características resistivas y difusivas de las láminas se evaluaron mediante técnicas electroquímicas, como espectroscopia de impedancia electroquímica (EIS, resistencia a la polarización (Rp y curvas potenciodinámicas. La composición y distribución de los productos de corrosión (FeO y algunos compuestos de cinc y el daño superficial causado por estos se determinaron por medio de DRX y SEM-EDS. Los resultados mostraron que la degradación de la capa de óxidos formada se ve afectada por la presencia de cloruros que penetran, llegan a la superficie del metal base y generan corrosión localizada.

  8. Influencia del polvo del horno de cemento sobre plantas y animales

    Directory of Open Access Journals (Sweden)

    Pajenkamp, H.

    1963-06-01

    Full Text Available Not availableEl pretendido «polvo de cemento» de los alrededores de las fábricas no es de cemento, sino que se compone, en su mayor parte, de caliza molida muy fina. Es, por tanto, un producto intermedio de la fabricación del cemento. Sería mucho más correcto llamarle «polvo del horno de cemento». Continuamente alegan los agricultores que este «polvo del horno de cemento» es dañino para plantas y animales, y en los últimos años, para probar la validez de tales asertos, se han llevado a cabo numerosas investigaciones científicas para estudiar los efectos de este polvo. Estamos hoy día en posesión de una serie· de trabajos muy completos que dan una idea clara sobre el efecto del polvo del horno de cemento. Los animales domésticos útiles (por ejemplo: corderos, vacas de leche no sufren ningún perjuicio clínico, ninguna deficiencia de su estado general, a pesar de serie administradas grandes dosis de polvo. Los ensayos agrícolas con plantas útiles (avena, trébol, remolacha azucarera, pastos que han sido efectuados durante varios años, han demostrado que ni siquiera cantidades elevadas de polvo provocan perjuicios ni influencias nefastas sobre el crecimiento y sobre la recolección.

  9. Influencia del Pseudo Dionisio en Nicolás de Cusa

    Directory of Open Access Journals (Sweden)

    Andrés Hubert R

    2007-01-01

    Full Text Available Nicolás de Cusa (1401-1464 reconoce la influencia del Pseudo Dionisio en su propio pensamiento, especialmente en su teología negativa. Este trabajo busca mostrar esta influencia en el libro referencia del Cusano: el De Docta Ignorantia (la Docta Ignorancia. Esta obra consta de 3 partes. Solo en la primera parte, Nicolás sigue de cerca las ideas del Pseudo Dionisio y solo en ella lo cita. En las demás, aunque se nota la influencia, nuestro autor se siente más libre: las fundaciones están firmes, el constructor puede construir libremente. Para probar esta tesis, se toman dos ejemplos: el tema de las tinieblas y la coincidencia de los opuestos. Este ejercicio permite conocer cómo y por qué se recibió al Pseudo Dionisio en la historia de la teología. Permite también profundizar el sentido de la teología de Nicolás de CusaThe reflections of Nicolas of Cusa (1401-1464 recognise the influence of Pseudo Dyonisius, particularly in his negative theology. The present study shows this influence on Nicolas' most important book: the De Docta Ignorantia (the Learned Ignorance. The book is divided into three parts and it is in the first part that Nicolas directly pursues the ideas of Pseudo Dyonisius and it is only here that he quotes them. In the other parts of the book although the influence is noted, the foundations have been set and are solid and the author or builder can construct with freedom. To prove this thesis, 2 examples are presented: the theme of darkness and the coincidence of opposites. This exercise shows how and why Pseudo Dyonisius has been accepted into the history of the theology. It also deepens the meaning of the Nicolas of Cusa's theology

  10. QUALIDADE FÍSICO-QUÍMICA DA UVA E PERFIL SENSORIAL VÍNICO PARA DIFERENTES CULTIVARES DE VIDEIRA SUBMETIDAS À PODA MECANIZADA

    Directory of Open Access Journals (Sweden)

    ANTONIO ODAIR SANTOS

    2015-06-01

    Full Text Available Estudos ao longo do Globo têm mostrado que a mecanização da poda, dentre outros processos de manejo da videira, é adequada para a obtenção de vinhedos com “stands” bem formados e com qualidade de produção equivalente ou superior àqueles conduzidos sob manejo manual, sobretudo com economia de capital humano e financeiro. Informações sobre o padrão de poda que influencia diretamente a ecofisiologia do dossel, a composição do rendimento e a qualidade de derivados da uva são existentes para condições de manejo tradicional manual, mas incipientes para a uma condição mecanizada, no Brasil. Um experimento foi realizado com Vitis sp. e Vitis vinifera, visando a estudar os impactos da adoção inicial da poda mecanizada, sobre a composição do rendimento, qualidade da uva e perfil sensorial dos vinhos produzidos no experimento. Os resultados mostraram que a aplicação da poda mecanizada em vinhedos tradicionais causou pequenas flutuações na qualidade da uva, em duas safras analisadas.

  11. Calculation of direct effects of {sup 60}Co gamma rays on the different DNA structural levels: A simulation study using the Geant4-DNA toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Tajik, Marjan; Rozatian, Amir S.H. [Department of Physics, University of Isfahan, Hezar Jarib Street, Isfahan 81746-73441 (Iran, Islamic Republic of); Semsarha, Farid, E-mail: Semsarha@ibb.ut.ac.ir [Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box: 13145-1384, Tehran (Iran, Islamic Republic of)

    2015-03-01

    In this study, simple single strand breaks (SSB) and double strand breaks (DSB) due to direct effects of the secondary electron spectrum of {sup 60}Co gamma rays on different organizational levels of a volume model of the B-DNA conformation have been calculated using the Geant4-DNA toolkit. Result of this study for the direct DSB yield shows a good agreement with other theoretical and experimental results obtained by both photons and their secondary electrons; however, in the case of SSB a noticeable difference can be observed. Moreover, regarding the almost constant yields of the direct strand breaks in the different structural levels of the DNA, calculated in this work, and compared with some theoretical studies, it can be deduced that the direct strand breaks yields depend mainly on the primary double helix structure of the DNA and the higher-order structures cannot have a noticeable effect on the direct DNA damage inductions by {sup 60}Co gamma rays. In contrast, a direct dependency between the direct SSB and DSB yields and the volume of the DNA structure has been found. Also, a further study on the histone proteins showed that they can play an important role in the trapping of low energy electrons without any significant effect on the direct DNA strand breaks inductions, at least in the range of energies used in the current study.

  12. Los niños, la influencia de la televisión y el rendimiento escolar

    OpenAIRE

    Pauta Guevara, Ricardo Arturo

    2015-01-01

    La presente investigación titulada “Los niños, la influencia de la televisión y el rendimiento escolar”, tiene como objetivo general mostrar la influencia que ejerce la Televisión en el comportamiento y en el rendimiento escolar de los niños de 6 a 9 años de edad, de clase media de Lima. Los medios de comunicación hoy en día, son parte de nuestra vida. Nos acompañan y entretienen, ponen a nuestro alcance lo ajeno y lejano, alientan nuestra imaginación con personajes e historias, nos mantienen...

  13. Impacto da Educação na Renda das Famílias Rurais da Amazônia: Uma Análise a Partir da Agricultura Familiar no Acre.

    Directory of Open Access Journals (Sweden)

    Francisco Dietima da Silva Bezerra

    2014-10-01

    Full Text Available No Brasil, tem se observado nas últimas décadas, a persistência de um quadro histórico de alta desigualdade de renda que têm contribuindo para que o país seja considerado como uma das nações mais desiguais do planeta. Dentre os fatores que têm contribuído para manter as disparidades de rendimentos em patamares tão elevados, destaca-se a heterogeneidade educacional, principalmente no meio rural. Diante da importância do tema tratado, a presente pesquisa consiste em analisar o impacto da educação no desempenho econômico das famílias rurais do Estado do Acre. Utiliza-se a metodologia do projeto de pesquisa Análise Socioeconômica dos Sistemas de Produção Familiar no Estado do Acre (ASPF, desenvolvido pelo Centro de Ciências Jurídicas e Sociais Aplicadas (CCJSA da Universidade Federal do Acre (UFAC, a partir de indicadores de resultado econômico e medidas de relação. Os resultados indicam que no Vale do Acre o nível de escolaridade influencia significativamente no desempenho econômico das famílias analisadas, diferentemente do Vale do Juruá, em que o desempenho econômico tem menor relação com a escolaridade das famílias e é mais fortemente condicionado por outros fatores estruturais e/ou de mercado.

  14. Development of a computational system based in the code GEANT4 for dosimetric evaluation in radiotherapy

    International Nuclear Information System (INIS)

    Oliveira, Alex Cristovao Holanda de

    2016-01-01

    The incidence of cancer has grown in Brazil, as well as around the world, following the change in the age profile of the population. One of the most important techniques and commonly used in cancer treatment is radiotherapy. Around 60% of new cases of cancer use radiation in at least one phase of treatment. The most used equipment for radiotherapy is a linear accelerator (Linac) which produces electron or X-ray beams in energy range from 5 to 30 MeV. The most appropriate way to irradiate a patient is determined during treatment planning. Currently, treatment planning system (TPS) is the main and the most important tool in the process of planning for radiotherapy. The main objective of this work is to develop a computational system based on the MC code Geant4 for dose evaluations in photon beam radiotherapy. In addition to treatment planning, these dose evaluations can be performed for research and quality control of equipment and TPSs. The computer system, called Quimera, consists of a graphical user interface (qGUI) and three MC applications (qLinacs, qMATphantoms and qNCTphantoms). The qGUI has the function of interface for the MC applications, by creating or editing the input files, running simulations and analyzing the results. The qLinacs is used for modeling and generation of Linac beams (phase space). The qMATphantoms and qNCTphantoms are used for dose calculations in virtual models of physical phantoms and computed tomography (CT) images, respectively. From manufacturer's data, models of a Varian Linac photon beam and a Varian multileaf collimator (MLC) were simulated in the qLinacs. The Linac and MLC modelling were validated using experimental data. qMATphamtoms and qNCTphantoms were validated using IAEA phase spaces. In this first version, the Quimera can be used for research, radiotherapy planning of simple treatments and quality control in photon beam radiotherapy. The MC applications work independent of the qGUI and the qGUI can be used for

  15. 32 CFR Appendix F to Part 623 - Power of Attorney (DA Form 4881-4-R)

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Power of Attorney (DA Form 4881-4-R) F Appendix F to Part 623 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY SUPPLIES AND EQUIPMENT LOAN OF ARMY MATERIEL Pt. 623, App. F Appendix F to Part 623—Power of Attorney (DA Form 4881-4-R...

  16. A dor e o protagonismo da mulher na parturição

    Directory of Open Access Journals (Sweden)

    Raquel da Rocha Pereira

    2011-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVO: Compreender pela teoria das representações sociais, as dimensões socioculturais da dor e seu impacto no protagonismo da mulher na parturição. MÉTODO: Para a investigação, utilizou-se a metodologia qualitativa, com o referencial teórico da fenomenologia e da teoria da representação social. Foram realizadas 45 entrevistas semiestruturadas com gestantes dos serviços público e privado de saúde de Joinville, SC, com no mínimo quatro consultas de pré-natal e que estavam no terceiro trimestre de gestação. RESULTADOS: Da análise de conteúdo das falas, emergiram três categorias empíricas: medos e preocupações, vivências e influência sociocultural, as quais possibilitaram construir três categorias interpretativas: modelo biomédico, desinformação e papel da mulher na decisão pela via de parto. Os achados relatados neste artigo evidenciam a dor como um dos elementos construtores das representações sociais feminina sobre a parturição. Observou-se que a dor influencia o comportamento da gestante a partir do medo e se torna a gênese de outros sentimentos aversivos e preocupações que envolvem o evento da parturição. CONCLUSÃO: Nesse contexto, a dor revela-se como um dos principais construtores das atuais representações sociais femininas sobre a parturição e contribui para a curva ascendente nos índices de cesárea no Brasil.

  17. DA NECESSIDADE DE EFETUAÇÃO DA REPRESENTAÇÃO DA VÍTIMA NOS CRIMES DE VIOLÊNCIA DOMÉSTICA CONTRA A MULHER, À LUZ DA AÇÃO DIRETA DE INCONSTITUCIONALIDADE 4.424/DF.

    Directory of Open Access Journals (Sweden)

    Ozana Rodrigues Boritza

    2018-03-01

    Full Text Available Este trabalho possui a finalidade de discutir acerca da necessidade de efetuação da representação criminal da vítima, em casos de violência doméstica e familiar contra a mulher, sob o enfoque da decisão proferida pelo Supremo Tribunal Federal no julgamento da Ação Direta de Inconstitucionalidade 4.424/DF. Procurar-se-á demonstrar quão antiga é a condição de submissão da mulher, através de um estudo das sociedades ao longo da história, abordando suas características, a fim de identificar a herança deixada por estas para a sociedade atual. Será apreciada a Lei 11.340/06 (Maria da Penha, destacando as razões de sua criação, seus objetivos, fins sociais e as modificações que efetuou no ordenamento jurídico nacional ao entrar em vigor. Buscar-se-á entender no que consiste a violência doméstica e familiar contra a mulher, suas formas de expressão, as peculiaridades presentes em tal situação, vislumbrando elencar também os motivos que impedem muitas vítimas de denunciar seus agressores.

  18. Efficiency corrections in determining the (137)Cs inventory of environmental soil samples by using relative measurement method and GEANT4 simulations.

    Science.gov (United States)

    Li, Gang; Liang, Yongfei; Xu, Jiayun; Bai, Lixin

    2015-08-01

    The determination of (137)Cs inventory is widely used to estimate the soil erosion or deposition rate. The generally used method to determine the activity of volumetric samples is the relative measurement method, which employs a calibration standard sample with accurately known activity. This method has great advantages in accuracy and operation only when there is a small difference in elemental composition, sample density and geometry between measuring samples and the calibration standard. Otherwise it needs additional efficiency corrections in the calculating process. The Monte Carlo simulations can handle these correction problems easily with lower financial cost and higher accuracy. This work presents a detailed description to the simulation and calibration procedure for a conventionally used commercial P-type coaxial HPGe detector with cylindrical sample geometry. The effects of sample elemental composition, density and geometry were discussed in detail and calculated in terms of efficiency correction factors. The effect of sample placement was also analyzed, the results indicate that the radioactive nuclides and sample density are not absolutely uniform distributed along the axial direction. At last, a unified binary quadratic functional relationship of efficiency correction factors as a function of sample density and height was obtained by the least square fitting method. This function covers the sample density and height range of 0.8-1.8 g/cm(3) and 3.0-7.25 cm, respectively. The efficiency correction factors calculated by the fitted function are in good agreement with those obtained by the GEANT4 simulations with the determination coefficient value greater than 0.9999. The results obtained in this paper make the above-mentioned relative measurements more accurate and efficient in the routine radioactive analysis of environmental cylindrical soil samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. La influencia externa en las políticas educativas de Argentina, Brasil y Chile (1990-2006)

    OpenAIRE

    Rambla, Francesc Xavier,

    2009-01-01

    El objetivo del artículo es analizar el papel que juega la influencia internacional en el diseño y aplicación de políticas educativas en el Cono Sur. Específicamente pretende explorar el proceso a través del cual las ideas, recomendaciones y metas globales modelan las políticas educativas latinoamericanas. Para ello, el artículo se centra en el programa de Educación para Todos en el Acuerdo General de Comercio de Servicios, analizando los mecanismos de influencia externa que intervienen en ca...

  20. Physical models, cross sections, and numerical approximations used in MCNP and GEANT4 Monte Carlo codes for photon and electron absorbed fraction calculation.

    Science.gov (United States)

    Yoriyaz, Hélio; Moralles, Maurício; Siqueira, Paulo de Tarso Dalledone; Guimarães, Carla da Costa; Cintra, Felipe Belonsi; dos Santos, Adimir

    2009-11-01

    Radiopharmaceutical applications in nuclear medicine require a detailed dosimetry estimate of the radiation energy delivered to the human tissues. Over the past years, several publications addressed the problem of internal dose estimate in volumes of several sizes considering photon and electron sources. Most of them used Monte Carlo radiation transport codes. Despite the widespread use of these codes due to the variety of resources and potentials they offered to carry out dose calculations, several aspects like physical models, cross sections, and numerical approximations used in the simulations still remain an object of study. Accurate dose estimate depends on the correct selection of a set of simulation options that should be carefully chosen. This article presents an analysis of several simulation options provided by two of the most used codes worldwide: MCNP and GEANT4. For this purpose, comparisons of absorbed fraction estimates obtained with different physical models, cross sections, and numerical approximations are presented for spheres of several sizes and composed as five different biological tissues. Considerable discrepancies have been found in some cases not only between the different codes but also between different cross sections and algorithms in the same code. Maximum differences found between the two codes are 5.0% and 10%, respectively, for photons and electrons. Even for simple problems as spheres and uniform radiation sources, the set of parameters chosen by any Monte Carlo code significantly affects the final results of a simulation, demonstrating the importance of the correct choice of parameters in the simulation.

  1. Influencia de Gregorio de Nisa sobre Juan Escoto Eriúgena: Aproximación a partir del Periphyseon

    OpenAIRE

    Pachas, José Antonio

    2004-01-01

    A partir de los cinco libros del Periphyseon el autor intenta un acercamiento entre el pensamiento de Juan Escoto Eriúgena y Gregorio de Nisa, buscando sobre todo las principales influencias del segundo sobre el primero. Encuentra una plataforma de amplia base común entre ambos pensadores, marcada principalmente por un tipo de pensamiento circular según el esquema: procesión y retorno. Sin embargo, es notoria la influencia del Niseno sobre el Carolingio, principalmente cuando se trata de plan...

  2. An application of the GEANT3 geometry package to the description of the OPAL detector

    International Nuclear Information System (INIS)

    Allison, J.; Bullock, F.W.; Hobson, P.R.; Lorazo, B.; Mallet, J.; Patrick, G.; Possoz, A.; Rossi, A.; Bologna Univ.; Ward, D.R.; Ward, C.P.

    1987-01-01

    We present the general features of the GEANT3 package for coding the geometrical structure of a large and complex detector in the computer programs used for their design and analysis. This package has been developed in the context of Monte Carlo studies of detector performance but should be well matched to the problem of analysis. As a specific example, we illustrate the description of the OPAL detector for the Large Electron Positron collider at CERN and show the results of a sample study using this description. (orig.)

  3. Pharmacological profile of DA-6886, a novel 5-HT4 receptor agonist to accelerate colonic motor activity in mice.

    Science.gov (United States)

    Lee, Min Jung; Cho, Kang Hun; Park, Hyun Min; Sung, Hyun Jung; Choi, Sunghak; Im, Weonbin

    2014-07-15

    DA-6886, the gastrointestinal prokinetic benzamide derivative is a novel 5-HT4 receptor agonist being developed for the treatment of constipation-predominant irritable bowel syndrome (IBS-C). The purpose of this study was to characterize in vitro and in vivo pharmacological profile of DA-6886. We used various receptor binding assay, cAMP accumulation assay, organ bath experiment and colonic transit assay in normal and chemically constipated mice. DA-6886 exhibited high affinity and selectivity to human 5-HT4 receptor splice variants, with mean pKi of 7.1, 7.5, 7.9 for the human 5-HT4a, 5-HT4b and 5-HT4d, respectively. By contrast, DA-6886 did not show significant affinity for several receptors including dopamine D2 receptor, other 5-HT receptors except for 5-HT2B receptor (pKi value of 6.2). The affinity for 5-HT4 receptor was translated into functional agonist activity in Cos-7 cells expressing 5-HT4 receptor splice variants. Furthermore, DA-6886 induced relaxation of the rat oesophagus preparation (pEC50 value of 7.4) in a 5-HT4 receptor antagonist-sensitive manner. The evaluation of DA-6886 in CHO cells expressing hERG channels revealed that it inhibited hERG channel current with an pIC50 value of 4.3, indicating that the compound was 1000-fold more selective for the 5-HT4 receptor over hERG channels. In the normal ICR mice, oral administration of DA-6886 (0.4 and 2mg/kg) resulted in marked stimulation of colonic transit. Furthermore, in the loperamide-induced constipation mouse model, 2mg/kg of DA-6886 significantly improved the delay of colonic transit, similar to 10mg/kg of tegaserod. Taken together, DA-6886 is a highly potent and selective 5-HT4 receptor agonist to accelerate colonic transit in mice, which might be therapeutic agent having a favorable safety profile in the treatment of gastrointestinal motor disorders such as IBS-C and chronic constipation. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Una retórica de la influencia

    Directory of Open Access Journals (Sweden)

    Cecilia González

    2008-07-01

    Full Text Available Entre las últimas décadas del siglo XIX y las primeras del XX se publica en el Río de la Plata un número considerable de relatos anclados en los debates que recorren la cultura europea del momento y que giran en torno a fenómenos de influencia. Este denominador común se declina, según los textos, en una serie de temas privilegiados : hipnosis, sugestión, herencia, mimetismo, vampirismo, parasitismo, emanación de todo tipo de rayos, ondas y fluidos capaces de modificar el comportamiento de un ...

  5. La influencia social de los medios de comunicación en Twitter

    Directory of Open Access Journals (Sweden)

    Karines Rodríguez Díaz

    2017-06-01

    Full Text Available En este artículo se expone cómo se desarrolla la influencia social de los medios de comunicación sobre los usuarios en Twitter, durante la celebración de la VII Cumbre de la Asociación de Estados del Caribe (AEC. La investigación parte del análisis de un corpus de 1500 tuits con las etiquetas temáticas #CubaCaribe, #VIICumbreAEC, #CumbreAEC. Utilizando el análisis del discurso mediado por computador, los resultados muestran la habilidad de influencia de los medios de comunicación a través de patrones de repetición-reacción y en la construcción del consenso sobre la valoración del acontecimiento. El reporte de caso explica cómo los parlamentos mediáticos repercuten en la comunidad de usuarios en el contexto microblogging.

  6. Psicodinâmica da violência de grandes grupos e da violência de massas

    Directory of Open Access Journals (Sweden)

    Vamik D. Volkan

    Full Text Available A partir de Freud, as teorias psicanalistas sobre grandes grupos focalizam, principalmente, as percepções e os significados que, psicologicamente, os indivíduos atribuem a eles. Este texto analisa alguns aspectos sobre a psicologia dos grandes grupos e sua psicodinâmica interna e específica. Toma como referência grupos étnicos, nacionais, religiosos e ideológicos cujo pertencimento dos sujeitos iniciou-se na infância. O autor faz uma comparação entre o processo de luto em indivíduos e o processo de luto em grandes grupos para ilustrar por que é necessário investir no conhecimento da psicologia destes últimos como um objeto específico. O autor descreve, ainda, sinais e sintomas de regressão em grandes grupos. Quando há ameaça à identidade coletiva, pode ocorrer um processo de violência de massas que obviamente influencia a saúde pública.

  7. Recuperación de listeria monocytogenes dañada subletalmente por efecto de la congelación

    OpenAIRE

    Blanco Gutiérrez, María del Mar

    1995-01-01

    Se han estudiado distintos aspectos relacionados con la influencia que ejerce la congelación sobre la viabilidad y el daño celular sobre las listerias en general y l. Monocytogenes, asi como distintas cuestiones con relación a la detección de listerias a partir de muestras que han sufrido un proceso de congelación. Respecto a la primera parte, hemos observado que la resistencia de l. Monocytogenes a los efectos letales y subletales de la congelación (-20 c) se ve influenciada por la concentra...

  8. Melhoria da produtividade do processo de usinagem de uniões em ferro fundido maleável preto

    OpenAIRE

    Pereira, Sidnei

    2007-01-01

    Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Mecânica A produtividade é um dos fatores de maior impacto no desempenho de uma empresa, pois influencia diretamente nos custos dos produtos e no dimensionamento adequado da fábrica relacionado à produção, pessoas e tempos de máquinas paradas. Na usinagem especificamente, há muitas variáveis de processo que dificultam o trabalho de melhora no índice de produtividade...

  9. BRASIL BAJO INFLUENCIA NAPOLEÓNICA Y FRANCESA: LOS MENSAJEROS DE LA INDEPENDENCIA: MILITARES, LIBREROS Y PERIODISTAS

    OpenAIRE

    PUIGMAL, PATRICK

    2013-01-01

    La historiografía clásica presenta la independencia de Brasil como un evento particular, generalmente aislado del acontecer continental y sin hacer referencia a la influencia militar y política napoleónica. Este artículo tiene como propósito principal entender la emancipación brasileña en un contexto mucho más amplio y demostrar la amplia presencia e influencia napoleónica en el marco de la lucha militar y de la construcción del Estado nuevo, permitiendo así integrar a Brasil en un movimiento...

  10. A influencia da politica de recursos humanos na satisfação docente : o caso da Fundação Universidade Estadual do Oeste do Parana - FUNIOESTE

    OpenAIRE

    Nogueira, Paulo Roberto Chavarria

    1993-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro Socio-Economico O presente estudo analisou a política de recursos humanos da Fundação Universidade Estadual do Oeste do Paraná - FUNIOESTE e sua relação com a satisfação no trabalho, envolvendo os docentes lotados nos quatros campi da instituição, a saber: FACISA, FACIMAR, FACITOL e FECIVEL. Esta pesquisa objetivou identificar os componentes que integram a política de recursos humanos da FUNIOESTE, apurar o índice de s...

  11. 1. Bon Appétit! O Efeito da Assinatura do Chef de Cozinha para Pratos Tradicional e Gourmet

    Directory of Open Access Journals (Sweden)

    Mariana da Silva Lopes

    2017-12-01

    Full Text Available Apesar de o termo gourmet ser usual no campo da gastronomia, na área beverage and food management são escassos os estudos que investiguem esse fenômeno da culinária no comportamento do consumidor. Assim, o principal objetivo desse estudo é analisar o efeito da assinatura do Chef de cozinha em pratos com abordagens tradicional ou gourmet. Foram realizados dois experimentos com 257 consumidores no total. Os dados foram analisados por meio de técnicas descritivas e análise de variância. Os resultados indicaram que a assinatura do Chef de cozinha aumenta a intenção de compra do prato tradicional, mas não tem efeito sobre a percepção de qualidade. Já para o prato gourmet, ocorre de forma contrária, ou seja, aumenta a percepção de qualidade, mas não tem influencia sobre a intenção de compra do mesmo.

  12. INFLUENCIA DE LA COMPOSICION DE LA LECHE EN POLVO SOBRE LA ACTIVIDAD DE AGUA APLICANDO EL MODELO DE GAB

    Directory of Open Access Journals (Sweden)

    Julio Gil

    2016-01-01

    Full Text Available El presente trabajo, mediante el estudio de las isotermas de sorción a 25ºC, analiza la influencia sobre la actividad de agua (aw, de las diferentes composiciones de leche en polvo entera, descremada y reducida en lactosa. Justamente la incorporación de esta última a trabajos anteriores permite ampliar el comportamiento diferencial de los distintos componentes. E l trabajo permite establecer la relación entre el contenido de humedad de las leches en polvo estudiadas, con su actividad de agua (aw. Los resultados experimentales son evaluados con el modelo referencial de GAB , observando que el trazado de las isotermas y los parámetros del modelo se ajustan satisfactoriamente a los valores obtenidos . Se obser va la clara influencia de la presencia de los monosacáridos (glucosa y galactosa en la leche reducida en lactosa, que disminuyen la actividad a valores mayores a 0 . 4, debido a la mayor solubilidad de estos. El contenido graso en la leche entera, al no ser adsorbente se manifiesta en valores mayores para la actividad de agua.

  13. Relação entre necessidade de adornos com satisfação com imagem corporal e autoconceito profissional da equipe de enfermagem

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    Ana Cláudia Puggina

    2015-12-01

    Full Text Available Resumo Objetivo: Relacionar a sensação de falta de adornos com a satisfação da imagem corporal e o autoconceito profissional dos membros da equipe de enfermagem. Métodos: Estudo analítico quantitativo. Profissionais da equipe de enfermagem (n = 46 responderam a Escala de Autoconceito Profissional, a Escala de Avaliação da Satisfação da Imagem Corporal e um questionário de caracterização. Resultados: O escore médio total da Escala de Autoconceito Profissional foi de 111,6 (± 13,3 e da Escala Avaliação da Satisfação com a Imagem Corporal foi de 81,6 (± 14,1. Houve diferenças estatisticamente significativas na comparação da sensação de falta de adornos nas dimensões Realização (valor de p = 0,0074, Autoconfiança (valor de p = 0,0386 e Saúde (valor de p = 0,0109 da Escala Autoconceito Profissional. Conclusão: Indivíduos mais realizados, mais autoconfiantes, que mais percebem a influencia do trabalho na própria saúde e mais satisfeitos com a aparência não sentiram falta de adornos no ambiente hospitalar.

  14. Cuatro indicios de la influencia de la Declaración universal de los derechos humanos de 1948 en el constitucionalismo Colombiano

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    Juan Carlos Upegui Mejía

    2009-12-01

    Full Text Available El autor desarrolla la tesis de la influencia de la Declaración Universal de los Derechos Humanos de 1948 en el constitucionalismo colombiano a partir de la identificación de cuatro indicios: 1. el conocimiento y la invocación de la Declaración Universal por parte de varios delegatarios a la Asamblea Constituyente de 1991; 2. algunas cifras sobre la invocación de la Declaración Universal durante los primeros 16 años de funcionamiento de la Corte Constitucional colombiana; 3. algunos datos cualitativos sobre la influencia de la Declaración Universal en la concepción de los derechos fundamentales de la Corte Constitucional colombiana; y, finalmente, 4. una breve reseña de algunos manuales de derecho constitucional, donde se indica la forma en que estos han o no acogido los contenidos de la Declaración, así como la relación de esta última con el derecho interno.

  15. Institutional and Strategic Influences on IT Architecture Decisions: comparative case studies in Brazilian companiesInfluências Institucionais e Estratégicas em Decisões de Arquitetura de TI: estudo de casos comparados em empresas brasileiras Influencias Institucionales y Estratégicas en la toma de Decisiones de la Arquitectura de TI: estudio de casos en empresas brasileñas

    Directory of Open Access Journals (Sweden)

    SOUZA, Cesar Alexandre

    2013-09-01

    Full Text Available ABSTRACTThe aim of this paper is to examine the influences on IT architecture decisions by viewing it through the lens of Institutional Theory and of Strategic Choice Theory, using the comparative case studies. Institutional influence can be the result of an external action or of something internal within the organizational, whereas strategic influence is related to the voluntary behavior of managers. The case of a large-scale company, where there is extensive internal policy formalization, was compared to a midsize company with a less mature architecture level. In spite of their differences as to the use of IT architecture, similar findings appeared in both organizations concerning these two influences. Both types of influence act together: the strategic type was most mentioned during interviews, whereas the institutional type appeared in decisions related to innovation and risks.RESUMOEsta pesquisa tem como objetivo examinar as influências sobre as decisões de arquitetura de TI sob as lentes da Teoria Institucional e da Teoria da Escolha Estratégica por meio de estudos de casos comparados. A influência institucional pode ser proveniente de uma ação externa ou de algo interno à organização, ao passo que a influência estratégica está relacionada com a ação voluntária dos gestores. O caso de uma empresa de grande porte, que possui maior formalização de suas políticas, foi comparado com o de outra de médio porte, que está em um estágio de maturidade de arquitetura menos avançado. As duas organizações, apesar de haver diferenças em relação ao uso da arquitetura de TI, apresentaram resultados semelhantes relacionados à atuação dessas duas influências. Ambas as influências agem em conjunto: a estratégica foi a mais mencionada pelos entrevistados e a institucional apareceu pontualmente em decisões que envolviam inovação e riscos.RESUMENA partir de la Teoría Institucional y de la Teoría de la Elección Estrat

  16. Posibles factores que producen la caída de fruto de Myrciaria dubia (HBK Mc Vaugh, "camu camu" durante la fenología reproductiva de la colección "cinco cuencas" en el centro experimental San Miguel - IIAP, Loreto, Perú

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    Sonia Farro

    2010-01-01

    Full Text Available Se evaluaron plantas de “camu camu” en cinco cuencas de Loreto (Perú, según el porcentaje de frutos con síntomas de infestación por plagas, la retención de flores y frutos en cada una de las cuencas y diámetros de ramas, y la influencia de la precipitación y temperatura en el proceso de caída de frutos según el estado fenológico. En el factor genético, la cuenca del río Putumayo destacó por presentar mayor retención de frutos, mayor rendimiento y peso promedio de frutos, así como menor ataque por plagas. Durante el proceso fenológico que duró 12 semanas, la etapa crítica de caída de flores y frutos ocurrió durante las primeras 7, siendo la retención de flores del 5.12%. Las plagas observadas son causantes del 9.27% de la caída, siendo el 9.15% causada por Edessa sp., y 0.12% por Conotrachellus dubiae. El otro 90.73% fue originado por otros factores no determinados tales como fisiológicos, nutritivos, competencia, vientos, lluvia. Los factores ambientales de temperatura y precipitación, ejercen una influencia directa e inversamente proporcional a la caída de frutos, respectivamente.

  17. ANÁLISE ESPACIAL DA TEMPERATURA E DA PRECIPITAÇÃO MEDIA ANUAL NO ESTADO DE SÃO PAULO / SPATIAL ANALYSIS OF MEAN ANNUAL TEMPERATURE AND RAINFALL FOR THE SÃO PAULO STATE

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    SIDNEY R. VIEIRA

    2009-11-01

    Full Text Available O objetivo deste trabalho foi analisar a variabilidade espacial da temperatura e da precipitação média anual no Estado de São Paulo. Foram utilizados dados de 416 estações climatológicas, referente ao período de 1936 a 1992 e analisados dois parâmetros climatológicos (temperatura média anual e precipitação pluvial média anual. Os dados foram analisados por meio da estatística descritiva e dageoestatística, para posterior construção de mapas de variabilidade espacial. Os resultados evidenciam que a altitude (m e a temperatura média anual (ºC apresentaram baixos valores de efeito pepita enquanto que a precipitação pluvial média anual (mm apresentou um maior pra esseparâmetro. A temperatura média anual (ºC e a precipitação pluvial média anual (mm apresentaram periodicidade detectada por meio do semivariograma experimental. Os mapas de distribuição espacial evidenciam a influencia da altitude sobre os valores estimados por krigagem para temperatura médiaanual (ºC e precipitação pluvial média anual (mm.

  18. Influencia lunar en cultivos, animales y ser humano

    OpenAIRE

    Mera Andrade, Rafael; Artieda Rojas, Jorge; Muñoz Espinoza, Manolo; Romero Viamonte, Katherine

    2017-01-01

    Los saberes ancestrales son la base para solucionar problemas de manera sencilla. La luna, desde tiempos pasados se ha mostrado como un indicador de afectaciones tanto en el suelo, los animales de distintas regiones y el hombre. La influencia lunar tiene un gran efecto en la pecuaria, debido a que los animales dependen de la luminosidad para alimentarse o salvaguardar su vida, las fases lunares tienen un efecto positivo en la ganadería y en los animales marinos ya que benefician algunos aspec...

  19. Avaliação da expressão imunoistoquímica da proteína p16INK4a no adenocarcinoma de esôfago Protein p16INK4a immunohistochemical expression in adenocarcinoma of the esophagus

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    Mário Henrique Osanai

    2011-12-01

    Full Text Available INTRODUÇÃO: O adenocarcinoma de esôfago apresenta aumento de frequência nas últimas décadas, particularmente em países desenvolvidos. O esôfago de Barrett é reconhecido como a principal lesão precursora e o estudo da sequência metaplasia-displasia-adenocarcinoma mostra a ocorrência de alterações genéticas desde suas fases mais incipientes. As alterações no p16INK4a são relatadas como frequentes no esôfago de Barrett e no carcinoma de esôfago. OBJETIVO: Verificar a prevalência da expressão imunoistoquímica da proteína p16INK4a em exames anatomopatológicos de pacientes com adenocarcinoma de esôfago. MÉTODO: A população do estudo foi constituída de 37 pacientes com adenocarcinoma de esôfago. A expressão da proteína p16 foi detectada por meio de análise imunoistoquímica, com anticorpo primário p16INK4aAb-7, clone 16P07, NeoMarkers e avaliada de acordo com o Sistema de Escore de Imunorreatividade (Immunoreactive scoring system - IRS modificado. RESULTADOS: No grupo houve predominância de pacientes do sexo masculino (86,5% e a maioria dos casos correspondia a estádios avançados (III e IV = 67,5%. Em 12 casos (32,4% foi identificada expressão imunoistoquímica da proteína p16INK4a. Não foi observada relação significativa entre a perda da expressão da proteína p16INK4a e o grau de diferenciação histológica (p=0,81 nem com o estadiamento da doença (p=0,485. CONCLUSÃO: Ocorre perda da expressão imunoistoquímica da proteína p16INK4a, corroborando as informações de que a inativação do gene p16 é um evento frequente e que pode exercer papel importante na carcinogênese do adenocarcinoma de esôfago.BACKGROUND: The esophageal adenocarcinoma shows an increasing frequence in the last decades, specially in the developed countries. The Barrett´s esophagus is accepted as the major premalignant lesion and the metaplasia-dysplasia-adenocarcinoma sequence presents a lot of genetic changes since its early

  20. Efeito da idade e da posição radial na densidade básica e dimensões dos traqueídeos da madeira de Pinus taeda L. Effect of age and of the radial position in the basic density and dimensions of the tracheids of the wood of Pinus taeda L.

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    Rita de Cássia SOUSA

    2007-12-01

    Full Text Available O Pinus taeda L. é uma conífera exóticacultivada no Brasil. A madeira dessa espécie éutilizada na construção civil, dormentes, laminação,postes, resina, celulose e serraria. A questão básicaabordada no presente trabalho foi verificar se aidade da árvore influencia na densidade básica enas dimensões dos traqueídeos da madeira eanalisar as possíveis variações dessas propriedades,no sentido medula-casca, ao longo do raio dastoras de P. taeda. As propriedades estudadas foram:densidade básica (DB, comprimento, diâmetro eespessura da parede dos traqueídeos em função daidade em relação à posição radial. As propriedadesem estudo foram determinadas no Laboratório deAnatomia e Qualidade da Madeira do InstitutoFlorestal do Estado de São Paulo. Foram amostradascinco árvores no DAP (diâmetro à altura do peito,1,30 m médio em cada uma das idades de 9, 13e 20 anos de populações comerciais da região deSengés/PR. Os resultados indicaram que a idade daárvore influencia diretamente nessas propriedadesque são diferenciadas na posição radial da madeirade P. taeda. Também foi observado que ocorreuuma correlação positiva alta entre a densidadebásica e o comprimento dos traqueídeos.The Pinus taeda L. is an exotic conifercultivated in Brazil. The wood of that species isused in civil constructions, sleepers, veneer, posts,resin, cellulose and sawmill. The subject approachedin the present work was to verify if the age of thetree influences in the basic density and in thedimensions of the tracheids of the wood and toanalyze the possible variations of those properties,in the sense from pith to bark, along the ray of thelogs of P. taeda. The studied properties were: basicdensity (DB, length, diameter and thickness ofthe wall of the tracheids in function of the agerelated with the radial position. The properties instudy were established in the Laboratory of Anatomyand Quality of the Wood of the Forestry Institute ofSão Paulo

  1. Dimensões e indicadores da qualidade de vida e do bem-estar no trabalho

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    Cleide Aparecida da Silva

    Full Text Available Investigou-se a influência de dimensões da qualidade de vida e bem-estar no trabalho (salários e benefícios; oportunidades de uso e desenvolvimento das próprias competências; condições físicas e de segurança no ambiente de trabalho; relacionamento e comunicação entre supervisores e empregados; relacionamento interpessoal com colegas de trabalho sobre seus indicadores (comprometimento organizacional afetivo, satisfação no trabalho, afetos positivos dirigidos ao trabalho. Duzentos e oitenta e quatro empregados do setor elétrico estatal responderam a escalas de avaliação dos diferentes construtos investigados. As oportunidades de uso e desenvolvimento das próprias competências foram o principal preditor positivo dos três indicadores considerados. Tais oportunidades caracterizam-se como um recurso motivacional do contexto laboral que influencia positivamente os indicadores da qualidade de vida e bem-estar no trabalho.

  2. Variação da concentração de vitamina C, ºBrix e acidez em néctar de laranja em embalagens cartonadas = Modification of vitamin C concentration, Brix and acidity in orange nectar in aseptic packaging

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    Telma Lucia de Oliveira

    2007-07-01

    Full Text Available Amostras de néctar de laranja, acondicionadas em embalagens cartonadas, foram armazenadas em local climatizado (25°C e em refrigerador (4°C. Durante oito semanas, análises de vitamina C, Brix e acidez foram realizadas no momento da abertura daembalagem, e seu produto residual foi ainda analisado durante quatro dias de estocagem em refrigerador. Analisando-se os resultados das variáveis por métodos estatísticos, observou-se que a temperatura de armazenagem influencia a quantidade de vitamina C do néctar delaranja. Ocorre decréscimo significativo na concentração de vitamina C, mas não há influência da temperatura de armazenagem no Brix e acidez do produto. O tempo de armazenamento influencia vitamina C, Brix e acidez. Constata-se, ainda, que após oito semanas de estocagem e quatro dias de abertura da embalagem a quantidade de vitamina C,em um copo de 200 mL do néctar de laranja estudado, supre a necessidade média diária de um adulto (60 mg.Samples of orange nectar in aseptic packaging were stored incontrolled room temperature (25°C and in a refrigerator (4°C. For eight weeks, analyses of vitamin C, Brix and acidity were conducted as the packages were opened, and their residual products were further analyzed during a period of four days stored in a refrigerator.By using statistical models from the results found, it was concluded that storage temperature influences the quantity of vitamin C in orange nectar. There was a significant decrease in vitamin C concentration in nectar, but storage temperature does not influenceacidity or Brix. Storage time does influence vitamin C, Brix and acidity. It was concluded that after eight weeks of storage and four days of opening the package, the amount of vitamin C in a 200 mL glass of orange nectar is enough to supply the average needed dailyintake (60 mg of vitamin C for an adult.

  3. Hoteles y sanatorios: influencia de la tuberculosis en la arquitectura del turismo de masas

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    Eduardo Jiménez Morales

    Full Text Available Resumen Este artículo pretende constatar la influencia que ha ejercido la tuberculosis en la formalización de la arquitectura del turismo de masas. Para ello se repasa la evolución tipológica del hotel a partir de la eclosión del sanatorio antituberculoso en el contexto de la estación turística alpina de mediados del siglo XIX. Un recorrido que se realiza tendiendo puentes entre los progresos en arquitectura y los avances en terapias médicas. El objetivo es hacer evidente el proceso de hibridación que se produce entre ambas tipologías arquitectónicas. Una imbricación que se extiende hasta la Segunda Guerra Mundial pero cuya influencia aún persiste en la arquitectura del turismo masivo de sol y playa.

  4. Influencia de la actividad física y la alimentación equilibrada en la mejora de la calidad de vida /

    OpenAIRE

    Vidaurrazaga Dobaran, Andoni

    2013-01-01

    Se estudia la influencia que la actividad física tiene en la calidad de vida de las personas. Es de sobra conocido que vivir de forma saludable es beneficioso para la salud pero se trata de esclarecer qué entendemos por “vivir de forma saludable” y cuál puede ser su influencia en el mantenimiento y mejora de la calidad de vida de las personas

  5. A condição sénior no Sul da Europa e na Escandinávia

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    António Calha

    2015-06-01

    Full Text Available O aumento da esperança média de vida associado a uma retração significativa da natalidade tem contribuído para um rápido envelhecimento das sociedades e uma profunda alteração da estrutura demográfica de muitos dos países europeus. Neste artigo, analisamos as especificidades da condição sénior nos países do Sul da Europa e da Escandinávia. Tratando-se de países com uma configuração de modelos de proteção social distintos, procuramos perceber se existem formas diferenciadas de viver a velhice nessas sociedades. Para tal, recorremos à análise dos resultados obtidos no European Social Survey (round 5 - 2010. A análise realizada revela que a existência de diferentes modelos que configuram a condição sénior nas sociedades em análise traduz-se em formas diferenciadas de lidar com o processo de envelhecimento. Concluímos que a condição de idoso não depende exclusivamente dos fatores biológicos relacionados com a limitação física, pois o contexto social em que se enquadra a vivência desse período da vida também influencia a condição sénior e a forma como os idosos a perspetivam.

  6. El ambiente emocional del aula y su influencia en el aprendizaje del niño de 4 a 5 años

    OpenAIRE

    Benavides Yépez, Diana Paola

    2003-01-01

    El presente trabajo bajo el tema “El ambiente emocional del aula y su influencia en el aprendizaje” está concebido para conocer y comprender mejor la relación y adaptación persona – ambiente y cómo los ambientes sociales en donde se lleva a cabo el aprendizaje pueden motivar o desmotivar a los niños a aprender y a comportarse. La vida del niño, como continuación del hogar, es la ampliación de su círculo de vida social al encontrar en el nivel preescolar nuevas condiciones de adaptación al ...

  7. AN IMPROVED SPECTROSCOPIC ANALYSIS OF DA WHITE DWARFS FROM THE SLOAN DIGITAL SKY SURVEY DATA RELEASE 4

    International Nuclear Information System (INIS)

    Tremblay, P.-E.; Bergeron, P.; Gianninas, A.

    2011-01-01

    We present an improved spectroscopic and photometric analysis of hydrogen-line DA white dwarfs from the Sloan Digital Sky Survey Data Release 4 (SDSS DR4) based on model atmospheres that include improved Stark broadening profiles with non-ideal gas effects. We also perform a careful visual inspection of all spectroscopic fits with high signal-to-noise ratios (S/Ns > 12) and present improved atmospheric parameters (T eff and log g) for each white dwarf. Through a comparison of spectroscopic and photometric temperatures, we report the discovery of 35 DA+DB/DC double degenerate candidates and two helium-rich DA stars. We also determine that a cutoff at S/N = 15 optimizes the size and quality of the sample for computing the mean mass of DA white dwarfs, for which we report a value of 0.613 M sun . We compare our results to previous analyses of the SDSS DR4 and find a good agreement if we account for the shift produced by the improved Stark profiles. Finally, the properties of DA white dwarfs in the SDSS are weighed against those of the Villanova White Dwarf Catalog sample of Gianninas et al. We find systematically lower masses (by about 3% on average), a difference that we trace back to the data reduction procedure of the SDSS. We conclude that a better understanding of these differences will be important to determine the absolute temperature scale and mean mass of DA white dwarfs.

  8. Violência no trabalho da Enfermagem: um olhar às consequências

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    Maiara Bordignon

    Full Text Available RESUMO Objetivo: refletir acerca das consequências da violência no trabalho experienciada por profissionais de enfermagem. Método: trata-se de um artigo de reflexão que contou com o auxílio de publicações recentes relacionadas a esta proposta, sobretudo de pesquisas realizadas no Brasil e em outros países. Resultados: a exposição à violência no trabalho tem sido vinculada a problemas de saúde nos profissionais de enfermagem, que se apresentam por danos físicos, manifestações emocionais, transtornos e distúrbios psíquicos. Além disso, influencia o desempenho do trabalhador, sua dimensão familiar e social. Conclusão: aponta-se para o potencial nocivo e oneroso deste fenômeno, por ser capaz de ocasionar sofrimento, adoecimento, afastamentos do trabalho e até a morte. Esta reflexão sensibiliza, ainda mais, para a importância de ambientes de trabalho seguros e em condições adequadas na área da saúde.

  9. Monte Carlo simulation of fission yields, kinetic energy, fission neutron spectrum and decay γ-ray spectrum for 232Th(n,f) reaction induced by 3H(d,n) 4He neutron source

    International Nuclear Information System (INIS)

    Zheng Wei; Zeen Yao; Changlin Lan; Yan Yan; Yunjian Shi; Siqi Yan; Jie Wang; Junrun Wang; Jingen Chen; Chinese Academy of Sciences, Shanghai

    2015-01-01

    Monte Carlo transport code Geant4 has been successfully utilised to study of neutron-induced fission reaction for 232 Th in the transport neutrons generated from 3 H(d,n) 4 He neutron source. The purpose of this work is to examine the applicability of Monte Carlo simulations for the computation of fission reaction process. For this, Monte Carlo simulates and calculates the characteristics of fission reaction process of 232 Th(n,f), such as the fission yields distribution, kinetic energy distribution, fission neutron spectrum and decay γ-ray spectrum. This is the first time to simulate the process of neutron-induced fission reaction using Geant4 code. Typical computational results of neutron-induced fission reaction of 232 Th(n,f) reaction are presented. The computational results are compared with the previous experimental data and evaluated nuclear data to confirm the certain physical process model in Geant4 of scientific rationality. (author)

  10. Portal transmídia mundo do sítio: análise do projeto transmídia do Sítio do Picapau Amarelo e sua relação com as demais extensões da obra de Monteiro Lobato

    OpenAIRE

    Rubens Francisco Torres

    2014-01-01

    Importante autor da literatura infantojuvenil brasileira, Monteiro Lobato criou com seus livros do Sítio do Picapau Amarelo um universo que permanece e influencia o imaginário da população brasileira até hoje. Esse universo não se restringiu apenas à literatura, ele expandiuse também em outras mídias ao longo de quase noventa anos, por meio de seriados televisivos, histórias em quadrinhos, cinema, entre outras mídias. Em 2011, tornou-se disponível o portal online Mundo do Sítio, primeiro prod...

  11. Sobre los determinantes y efectos de la influencia de politica (On the Determinants and Effects of Political Influence)

    OpenAIRE

    Alberto Chong; Mark Gradstein

    2007-01-01

    En este trabajo se emplea una encuesta de gran alcance entre empresas de varios países para evaluar su influencia en las políticas oficiales. Se halló que la influencia guarda una relación con empresas más grandes propiedad del Estado que tienen un alto grado de concentración de la propiedad. Por el contrario, la tenencia foránea tiene escasa importancia. También se descubrió que la medida en que se considera que las políticas gubernamentales y la legislación entorpecen el crecimiento de las ...

  12. Influencia que tienen los programas de televisión infantil en los argumentos del juego simbólico

    OpenAIRE

    Jácome R., María Esther

    2004-01-01

    La influencia negativa de los programas televisivos dirigidos ó no a niños de 4 a 5 años determinan los argumentos del juego infantil, esta situación se evidencia en las repetidas manifestaciones de agresividad en el entorno escolar y familiar; en el uso de términos despectivos que descalifican y ridiculizan a compañeros y amigos; en los argumentos de conversación frente al juego; en el rechazo a las actividades físicas que impliquen movimiento; en la asunción de roles y postur...

  13. Atores e ações na construção da governança corporativa brasileira

    Directory of Open Access Journals (Sweden)

    Grün Roberto

    2003-01-01

    Full Text Available Este ensaio procura analisar a evolução da cena econômica e institucional brasileira que vem produzindo uma nova relação entre as grandes empresas, seus acionistas e os intermediários financeiros e espraiando suas conseqüências sobre os sindicatos e a previdência. O autor aborda as vicissitudes das tentativas de instalação no Brasil do modelo de governança corporativa, usando as câmaras setoriais como um contraponto cognitivo. Apresenta também algumas particularidades da tramitação recente das leis que regulam a governança corporativa, enfocando as dificuldades enfrentadas pelos agentes que tentam trazer esse conceito, oriundo do mundo financeiro anglo-saxão, para a cena brasileira. A discussão pretende mostrar que, de um lado, as dificuldades são expressão da resistência do modelo de capitalismo brasileiro, que passa, atualmente, por um processo de deslegitimação causado pela prevalência dos partidários da globalização, considerados os intelectuais orgânicos das elites dominantes do momento; de outro, que os atores "globalizantes" recebem uma ajuda decisiva e aparentemente inesperada das cúpulas do movimento sindical, o que influencia bastante a disputa econômica e política travada em torno da implantação ou não da governança corporativa e seus contornos.

  14. La polémica influencia de Adolfo Posada en el pensamiento de los catedráticos de derecho de la generación del 900

    Directory of Open Access Journals (Sweden)

    Raquel García Bouzas

    2014-10-01

    Full Text Available Contenido: Las razones de la influencia de Posada entre los juristas rioplatenses. Un particular enfoque del krausismo. Receptividad y difusión de su pensamiento. Concepción organicista del estado. El sufragio como un deber.Valoración de su influencia en nuestra historia intelectual

  15. Influência da procainamida sobre o bloqueio neuromuscular produzido pelo rocurônio e investigação sobre o mecanismo de ação da procainamida na junção neuromuscular Influencia de la procainamida sobre el bloqueo neuromuscular producido por el rocuronio e investigación sobre el mecanismo de acción de la procainamida en la junción neuromuscular Influence of procainamide on the neuromuscular blockade caused by rocuronium and investigation on the mechanism of action of procainamide on the neuromuscular junction

    Directory of Open Access Journals (Sweden)

    Thalita Duque Martins

    2007-02-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A potencialização da procainamida sobre o bloqueio neuromuscular produzido pela d-tubocurarina já está comprovada, porém o mecanismo é controverso. O objetivo do estudo foi avaliar a influência da procainamida no bloqueio neuromuscular produzido pelo rocurônio e investigar os mecanismos desta interação. MÉTODO: Foram utilizados 15 ratos (250 a 300 g em preparação descrita por Bülbring. Formaram-se os seguintes grupos (n = 5 cada: procainamida - 20 µg.mL-1 (Grupo I; rocurônio - 4 µg.mL-1 (Grupo II e rocurônio - 4 µg.mL-1 e procainamida - 20 µg.mL-1 (Grupo III. Avaliaram-se: 1 a amplitude das contrações musculares sob estimulação indireta em cada grupo, antes e após a adição dos fármacos; 2 os potenciais de placa terminal em miniatura (PPTM; 3 a eficácia da 4-aminopiridina na reversão do bloqueio neuromuscular. O mecanismo da interação foi estudado em Biventer cervicis (n = 5 e diafragma de rato desnervado (n = 5, observando-se a influência da procainamida na resposta à acetilcolina antes e após a adição da procainamida. RESULTADOS: A procainamida isoladamente não alterou as respostas neuromusculares. O bloqueio produzido com o Grupo III foi de 68,6% ± 7,1%, com diferença significativa (p = 0,0067 em relação ao Grupo II (10,4% ± 4,5%, revertido pela 4-aminopiridina. A procainamida ocasionou aumento na freqüência dos PPTM, seguido de bloqueio revertido pela 4-aminopiridina. Em Biventer cervicis a procainamida aumentou a resposta à ação de contração da acetilcolina, resultado não observado com o diafragma desnervado. CONCLUSÕES: A procainamida potencializou o bloqueio produzido pelo rocurônio. As alterações observadas com PPTM e Biventer cervicis identificaram ação pré-sináptica. O antagonismo da 4-aminopiridina sobre o bloqueio dos PPTM sugeriu dessensibilização dos receptores pela procainamida.JUSTIFICATIVA Y OBJETIVOS: La potenciación de la procainamida sobre

  16. Influencia de la preparación física en el dominio técnico futbolista 12-14 años del Club el Nacional

    OpenAIRE

    Alomoto Navarrete, Rocío

    2014-01-01

    Siendo conocedores de la realidad deportiva ecuatoriana en la formación de deportistas en diferentes etápas sabiendo que en la étapa de inciación deportiva el aprendizaje de la técnica deportiva depende de una buena preparación física es importante analizar la influencia de la preparación física en el dominio técnico de futbolista 12-14 años así como su influencia en el dominio técnico de este deporte. El objetivo es proponer una programa de ejercicios para la influencia de la preparación fís...

  17. O comportamento do consumidor do setor farmacêutico diante da demanda não atendida – implicações para a cadeia de suprimentos

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Gouvêa

    2007-03-01

    Full Text Available Neste artigo é realizado um estudo sobre o comportamento dos clientes de uma drogaria, na situação de não haver encontrado o produto desejado. O objetivo deste estudo é avaliar o comportamento dos clientes, considerando a importância dos consumidores como elo final da cadeia de suprimentos de um setor. O comportamento de compra dos consumidores finais afeta decisivamente o gerenciamento da cadeia de suprimentos, uma vez que influencia a tomada de decisões das várias empresas da cadeia. Conhecer efetivamente o comportamento dos vários elos da cadeia, incluindo o consumidor final, traz inúmeras vantagens, entre elas maior compreensão de interligações especialmente significativas na cadeia, melhor gestão da capacidade produtiva, política de estocagem mais eficiente e facilidade para focalizar uma perspectiva de longo prazo. Um mapeamento das associações das possíveis decisões comportamentais dos clientes a suas características individuais foi obtido por meio da técnica de análise de correspondência múltipla. Essa análise permitiu maior compreensão de aspectos subjacentes ao comportamento dos clientes da drogaria que foi objeto de estudo deste trabalho.

  18. A força do cinema para a massificação ou para a promoção da diversidade cultural

    Directory of Open Access Journals (Sweden)

    Cecília Leão Oderich

    2017-12-01

    Full Text Available A imagem influencia a compreensão, o conhecimento, a formação ideológica de indivíduos e grupos. Este trabalho apresenta um ensaio que analisa a força do cinema como arte que pode tanto legitimar padrões em processos de apropriação, padronização e massificação cultural, quanto pode se constituir como um espaço de inclusão, de crítica, de diversidade cultural e diálogo intercultural. São apresentados exemplos de filmes e os desafios dos cinemas nacionais e do cinema independente quando buscam além da hegemonia do visual. A perspectivação sobre diferentes temas, desde questões étnicas, da obesidade, do colonialismo, da escolarização, da “deformidade”, por exemplo, pode ocorrer a partir do cinema de massa ou do cinema independente. A pesquisa sobre cinema pode ajudar na crítica anticolonizadora, no diálogo intercultural e na ampliação da tomada de consciência sobre a importância da arte e do cinema nas forças que conjuminam em modelos e padrões para uma suposta normalidade ou sucesso, na busca por relações menos estereotipadas.

  19. Influencia del tempo de la música en las emociones

    Directory of Open Access Journals (Sweden)

    Jonathan Azael Caballero-Meneses

    2010-01-01

    exposición de 24 estudiantes de licenciatura a treinta extractos musicales de distinto tempo. Además se evaluó la posible modulación de la relación tempo-valencia por el rasgo de personalidad extroversión/introversión. Los resultados confirmaron la influencia del tempo sobre el arousal, pero no sobre la valencia, así como una posible mediación de la dimensión de personalidad introversión-extroversión sobre la valencia.

  20. La influencia de la musicoterapia en ni??os con disfemia

    OpenAIRE

    P??rez Bazoco, M??nica

    2015-01-01

    En este trabajo se pretende realizar una peque??a investigaci??n sobre la influencia que tiene la musicoterapia en los ni??os que presentan disfemia. La musicoterapia es un medio de rehabilitaci??n que incide tanto desde el punto de vista fisiol??gico (como puede ser la ejercitaci??n de la voz), como desde la perspectiva emocional e intelectual, proporcionando un desarrollo afectivo y cognoscitivo. Por tanto, la din??mica planteada de modelos mel??dicos y r??tmicos parece repercutir en el des...

  1. Influencia sobre parámetros biológicos de Tagosodes orizicolus relacionados con el Virus Hoja Blanca y su permanencia en invernaderos.

    Directory of Open Access Journals (Sweden)

    Rafael Meneses

    2007-03-01

    Full Text Available Con el objetivo de determinar la influencia que ejerce el Virus Hoja Blanca (VHB sobre el insecto, se estudiaron tres colonias de T. orizicolus, procedentes de diferentes zonas arroceras de Colombia (Tolima, Costa y Jamundí En las colonias de Costa (3 años y Tolima, (9 meses, de multiplicación en condiciones semicontroladas de invernadero, no se encontró influencia negativa del virus en la longevidad de machos y hembras, y la fecundidad diaria, no ocurriendo de modo semejante en los insectos de Jamundí (4 meses que si se manifestaron efectos deletéreos en todos los parámetros antes señalados; aspecto éste muy importante en la interacción entre entomólogos, virólogos y mejoradores, en la calidad de las evaluaciones de resistencia a esta plaga y al VHB de las líneas de arroz, depende el grado de resistencia o susceptibilidad de la nuevas variedades comerciales y éste es el principal factor en el Manejo Integrado de T. orizicolus y del VHB.

  2. Evidências da relação entre a evolução da gestão ambiental e a adoção de práticas de green supply chain management no setor eletroeletrônico brasileiro

    Directory of Open Access Journals (Sweden)

    Ana Beatriz Lopes de Sousa Jabbour

    2014-09-01

    Full Text Available Na pesquisa apresentada, teve-se como objetivo verificar se a evolução da gestão ambiental se relaciona positivamente com a adoção de práticas de green supply chain management (GSCM por empresas do setor eletroeletrônico do Brasil. Para fazer frente ao objetivo exposto, foi realizada uma pesquisa quantitativa, por meio de um levantamento survey, com cem empresas do setor eletroeletrônico brasileiro. Os dados coletados foram processados por meio de técnicas estatísticas descritivas, análise fatorial exploratória e modelagem de equações estruturais. Os resultados mais importantes da pesquisa foram: na amostra, práticas de GSCM orientadas para a recuperação dos investimentos das empresas, como a revenda de materiais inservíveis e outros resíduos, além da adequação à legislação e à auditoria ambiental, obtiveram médias elevadas; e a hipótese de pesquisa (H1 foi confirmada e considerada estatisticamente válida, indicando que a evolução da gestão ambiental influencia a adoção de práticas de GSCM.

  3. Estudio de la influencia del lavado y del ensimaje sobre la estabilidad de hilatura y las propiedades de los hilados.

    OpenAIRE

    Coll Tortosa, Liberto; Palet Alsina, Daniel; Cegarra Sánchez, José; Gacén Guillén, Joaquín; Naik, Arun

    1995-01-01

    En el presente trabajo se estudia la influencia de un lavado deficiente de la lana sobre la estabilidad de hilatura y las propiedades de los hilados. El motivo de este estudio es solucionar el problema de la acumulación de residuos no hilables en los órganos de la máquina de hilar, que repercuten negativamente en la hilatura y en las propiedades de los hilados. Este problema fue abordado en un trabajo anterior (julio 91) en el que se analizó la influencia de la intensidad del aclarado, sin en...

  4. Adaptive track scheduling to optimize concurrency and vectorization in GeantV

    International Nuclear Information System (INIS)

    Apostolakis, J; Brun, R; Carminati, F; Gheata, A; Novak, M; Wenzel, S; Bandieramonte, M; Bitzes, G; Canal, P; Elvira, V D; Jun, S Y; Lima, G; Licht, J C De Fine; Duhem, L; Sehgal, R; Shadura, O

    2015-01-01

    The GeantV project is focused on the R and D of new particle transport techniques to maximize parallelism on multiple levels, profiting from the use of both SIMD instructions and co-processors for the CPU-intensive calculations specific to this type of applications. In our approach, vectors of tracks belonging to multiple events and matching different locality criteria must be gathered and dispatched to algorithms having vector signatures. While the transport propagates tracks and changes their individual states, data locality becomes harder to maintain. The scheduling policy has to be changed to maintain efficient vectors while keeping an optimal level of concurrency. The model has complex dynamics requiring tuning the thresholds to switch between the normal regime and special modes, i.e. prioritizing events to allow flushing memory, adding new events in the transport pipeline to boost locality, dynamically adjusting the particle vector size or switching between vector to single track mode when vectorization causes only overhead. This work requires a comprehensive study for optimizing these parameters to make the behaviour of the scheduler self-adapting, presenting here its initial results. (paper)

  5. Study on light output and energy resolution of PbWO4 crystal

    International Nuclear Information System (INIS)

    Su Guanghui; Yue Ke; Sun Zhiyu

    2010-01-01

    The light output and energy resolution of PbWO 4 crystal are studied with different wrapping materials and methods. The Wrapping condition was optimized by analyzing the experimental data to gain higher light output and better energy resolution. A GEANT4-based package has been developed to simulate the corresponding features of PbWO 4 crystal, and the simulation results are consistent with the experimental data. (authors)

  6. Craniocervical posture analysis in patients with temporomandibular disorder Análise da postura cranio-cervical em pacientes com disfunção temporomandibular

    Directory of Open Access Journals (Sweden)

    DH Iunes

    2009-02-01

    influencia na postura da cabeça e no posicionamento da coluna cervical. MÉTODOS: Noventa mulheres escolhidas aleatoriamente foram diagnosticadas por meio dos Critérios para Diagnóstico em Pesquisa para Disfunções Temporomandibulares (RDC/TMD por um examinador treinado e divididas em três grupos: grupo 1, diagnóstico de disfunção miofascial (grupo I do eixo I do RDC; grupo 2, com DTM mista (grupo I, II e III do eixo I do RDC e controle, sem DTM . Em seguida, foram fotografadas em vista anterior e em perfil por um único examinador. Para a realização dessas fotografias, foram demarcados sobre a pele os seguintes pontos anatômicos: protuberância occiptal, C4, C7, articulação acromioclavicular e esternoclavicular. A partir desses pontos, foram analisados diferentes ângulos por meio do aplicativo ALCimagem-2000. Essas mesmas fotos foram posteriormente avaliadas qualitativamente (avaliação visual. Em seguida, foi solicitada uma radiografia e uma telerradiografia em perfil. O examinador foi cego ao analisar as imagens. Para comparação dos resultados, foi utilizado o teste qui-quadrado e a análise de variância com nível de significância de 5%. RESULTADOS: Independentemente do método utilizado, os resultados revelaram que a postura da cabeça e da coluna cervical não diferem entre o grupo com DTM e sem DTM, independentemente do grupo diagnosticado. CONCLUSÃO: A postura do indivíduo com DTM miogênica ou artrogênica não é diferente do indivíduo sem DTM. A presença da DTM não influencia na postura da cabeça e da coluna cervical.

  7. Influencia familiar sobre las actitudes ante el consumo de drogas en adolescentes españoles

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    María de la Villa Moral Jiménez

    2013-08-01

    Full Text Available En la cultura mediterránea la familia sigue siendo la agencia socializadora por excelencia, a pesar de diversos cambios referenciales y en la intensidad de los afectos, así como en los estilos disciplinares característicos de nuevas tipologías de familias postmodernas. La influencia y modelado familiar sobre las actitudes ante el consumo de sustancias psicoactivas en adolescentes está bien establecida en indicadores tales como experiencias paternas con las drogas, apego y supervisión parental, clima afectivo, dinámica sociofamiliar, etc. Nuestro objeto de estudio se centra en el análisis psicosocial de tales indicadores, así como en ofrecer un análisis diferencial de la valoración de la relación paterno-filial en relación con las actitudes ante el consumo de drogas en un colectivo de adolescentes españoles. Se ha confirmado una mayor permisividad actitudinal y menor concienciación ante los efectos dañinos de las drogas en los hijos de padres consumidores de sustancias psicoactivas tanto legales como ilegales. Se confirma la importancia psicosocial del Apoyo más valorado por los adolescentes que no consumen drogas, así como la percepción diferencial del empleo del Castigo-Coerción y de la Reprobación en adolescentes consumidores que presentan niveles de mayor permisividad actitudinal.

  8. A influência da Ação Católica na atuação social e pastoral de D. Waldyr Calheiros: o caso dos Direitos Humanos na cidade Volta Redonda * La influencia de la Acción Catolica...

    Directory of Open Access Journals (Sweden)

    LUIZ FERNANDO MANGEA DA SILVA

    2014-09-01

    Full Text Available Resumo: O presente artigo faz uma análise da influência da Ação Católica na atuação social e pastoral de D. Waldyr Calheiros de Novaes na Diocese de Barra do Piraí/Volta Redonda, tendo como base o contexto sociopolítico nacional e local do início da década de 1950 até 1968. Essa atuação se inicia a partir do episódio referente à violação dos direitos humanos, em que operários da Companhia Siderúrgica Nacional e intelectuais volta-redondenses foram presos após uma comemoração pelos 20 anos da Declaração Universal dos Direitos do Homem. No evento, também foram comemorados os dois anos da chegada e posse do bispo à diocese. Houve, por parte da organização do evento, a iniciativa de incluir dramatizações que simbolizavam o universo dos trabalhadores. Não podemos esquecer que Volta Redonda era uma cidade militarizada, por causa da instalação do 1º Batalhão de Infantaria Blindada em Barra Mansa, cidade vizinha. O serviço de espionagem do regime militar identificou as lideranças operárias e intelectuais, o que resultou nas prisões dos organizadores do evento. Foi nesse episódio que o bispo se declarou preso no batalhão, em protesto contra a detenção dessas lideranças.Palavras-chave: Waldyr Calheiros de Novaes – Ação Católica – Ditadura Militar e Direitos Humanos. Resumen: Este artículo analiza la influencia de la Acción Católica en el trabajo social y pastoral D. Waldyr Calheiros de Novaes en la Diócesis de Barra do Piraí/Volta Redonda, en función del contexto socio-político nacional y local de la década de 1950 hasta 1968 . Dicha acción se inicia desde el episodio relativo a la violación de los derechos humanos, en el que los trabajadores nacionales Steel Company y los intelectuales era redondenses fueron arrestados después de una celebración para el 20 aniversario de la Declaración universal de los derechos humanos. En el evento, también se celebraron dos años de la llegada e

  9. La influencia católica en la configuración del sistema político y educativo nacional argentino a fines del siglo XIX

    Directory of Open Access Journals (Sweden)

    Oscar Daniel Duarte

    2014-05-01

    Full Text Available El presente artículo describe las diferentes corrientes de pensamiento que influenciaron en el proceso de conformación estatal argentino. Sobresalen entre ellas la línea liberal y la línea católica de fuerte influencia en la elite dirigente del país. A partir de allí realizamos un análisis sobre la orientación política tomada por el Estado y la influencia impelida por el catolicismo particularmente en el debate sobre la conformación del aparato educativo nacional. La conclusión a la que arribamos en este estudio explica el por qué del sometimiento político e ideológico al que se vio sujeto el Estado argentino respecto a la influencia del Vaticano.

  10. Astigmatismo interno : epidemiología, clasificación e influencia en los resultados de la cirugía refractiva corneal

    OpenAIRE

    Gargallo Martínez, Beatriz

    2015-01-01

    Objetivos: Trabajos previos muestran que la corrección astigmática mediante cirugía láser en sujetos con grandes cantidades de astigmatismo interno (AI) es menos predecible. La influencia exacta del AI en los resultados de la cirugía refractiva, así como la exactitud en su medida o su relación con el resto de estructuras ópticas del ojo se desconoce. Ésta tesis pretende estudiar y analizar la epidemiología del AI y su influencia en los resultados de la cirugía refractiva. Si aumentamos el ...

  11. VER À DISTÂNCIA: A PRODUÇÃO AUDIOVISUAL DE JOVENS HOMENS DE UMA ÁREA RURAL DA ÁFRICA DO SUL

    Directory of Open Access Journals (Sweden)

    Alex Vailati

    2014-12-01

    Full Text Available Este trabalho analisa a relação entre imaginação e produção audiovisual, entre um grupo de jovens homens em KwaMashabane, uma área rural da África do Sul. Através da metodologia vídeo-colaborativa serão analisadas as relações de poder que sustentam a produção de vídeos. O evidente papel subalterno dos jovens locais e a análise do processo de produção revelam diferentes níveis de hegemonia. Se a autoridade dos adultos não é ainda contestável pelos jovens, parece que os símbolos neoliberais, imagens e narrações estão tornando-se a maior retórica que influencia a imaginação dos jovens.

  12. The influence of aquatic humic substances characteristics on the coagulation efficiency using ferric chloride; Influencia das caracteristicas das substancias humicas aquaticas na eficiencia da coagulacao com o cloreto ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Sloboda, Eliane; Vieira, Eny Maria [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica], e-mail: elisloboda@hotmail.com; Dantas, Angela Di Bernardo; Bernardo, Luiz Di [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Hidraulica e Saneamento

    2009-07-01

    The aim of this study was to verify the influence of the apparent molecular size of aquatic humic substances on the effectiveness of coagulation with ferric chloride. Coagulation-filtration tests using jar test and bench-scale sand filters were carried out on samples of water with true color of approximately 100 Hazen units, prepared with aquatic humic substances of different molecular sizes (F{sub 1}: < 0.45 {mu}m, F{sub 2}: 100 kDa - 0.45 {mu}m, F{sub 3}: 30 - 100 kDa and F{sub 4}{sup '} : < 30 kDa). For the water samples with lower apparent molecular size fractions, greater dosages of coagulant was needed to remove the color around 5.0 Hanzen units, mainly because these water samples contain higher concentrations of fulvic acids, which exhibited a larger number of negatively-charged groups. (author)

  13. Influência dos Direcionadores do Uso da TI na Governança de TIThe Influence of Use Drivers in it GovernanceInfluencia de los Gestores del Uso de la TI en la Gobernanza de TI

    Directory of Open Access Journals (Sweden)

    SILVA, Brivaldo André Marinho da

    2011-03-01

    Full Text Available RESUMOO presente trabalho propõe-se a analisar como as dimensões que tipificam o ambiente organizacional, aqui entendidas como direcionadores do uso de Tecnologia de Informação (TI, influenciam na estruturação de sua governança. Para tanto, o quadro teórico apoiou-se nas relações das dimensões do uso da TI por meio de direcionadores de mercado, organizacional, do indivíduo e de TI, bem como na visão de sua governança, baseada em estágios dos processos de decisão de TI, mapeando-os nas principais decisões críticas, que envolvem seus princípios, arquitetura, infraestrutura, investimentos e priorização, bem como aplicações de negócio. O estudo propõe um modelo teórico resultante da revisão da literatura específica que, por meio da estratégia de estudo de caso, foi aplicado em entrevistas com os principais tomadores de decisão da estrutura de governança de uma instituição de educação profissional, atuante em nível nacional, somado às informações baseadas em registros internos e observação não participativa. Obteve-se que as características de investimentos em TI influenciam positivamente as principais decisões sobre sua governança, por meio dos direcionadores de uso que envolvem a instituição e que estão presentes nos fatores externos que impactam as principais decisões críticas da área, influenciando-as, exceto às relacionadas aos princípios de TI. Verificou-se também que o contexto interno não influencia diretamente todos os aspectos das decisões sobre a governança. Por fim, percebeu-se que a TI não é vista como elemento capaz de estruturar os arquétipos de governança pelo seu uso, ficando definidos pela hierarquia organizacional da instituição.ABSTRACTThis study aims to examine how the dimensions that typify the organizational environment, here understood as drivers of the use of Information Technology (IT, influence in structuring their governance. So, the theoretical framework has

  14. Morfotectônica da Bacia Hidrográfica do Rio Bonito, Petrópolis, RJ

    Directory of Open Access Journals (Sweden)

    Laura Delgado Mendes

    2007-11-01

    Full Text Available O objetivo deste trabalho é investigar o papel das estruturas subjacentes associadas à evolução tectônica regional e o seu reflexo na geomorfologia, a partir de uma abordagem morfotectônica na bacia do rio Bonito, localizada no extremo norte do município de Petrópolis, Planalto Serrano do Estado do Rio de Janeiro. As estruturas identificadas na área correspondem a falhas e famílias de juntas, que estão relacionadas com as descontinuidades de caráter regional e diretamente associadas ao contexto geológico regional ao qual se inserem, exibindo condições significativamente marcadas pelos processos vinculados à ruptura continental e abertura do Oceano Atlântico, iniciados a partir do Jurássico Superior, especialmente pela reativação de descontinuidades preexistentes. O controle tectônico-estrutural se reflete na compartimentação morfotectônica a partir (ada integração dos dados estruturais, da análise dos lineamentos da rede de drenagem, que definem trends de lineamentos que correspondem a estruturas identificadas e medidas, (b do relevo, que apresenta escalonamentos e o desenvolvimento de vales suspensos, e (c da distribuição espacial da cobertura sedimentar que reproduz a complexidade de feições observadas tanto no contexto local quanto no regional. Dessa maneira, tendo como princípio que a tectônica influencia diretamente a evolução da paisagem, os dados obtidos mostram uma interferência direta das estruturas na compartimentação morfotectônica e na dinâmica e evolução da paisagem da área em estudo.

  15. Influencia da largura do corpo-de-prova na medida da tenacidade do concreto reforçado com fibras de aço

    OpenAIRE

    Ana Maria Oliveira Villares

    2001-01-01

    Resumo: A quantificação da tenacidade dos concretos reforçados com fibras de aço (CRFA) pode ser afetada por diversos fatores, dependendo do método adotado e do procedimento para realizar o ensaio de flexão sob deformação controlada. Esses fatores incluem entre outros: configuração do ensaio, configuração do carregamento, taxa e controle do carregamento, tipo de equipamento para medida do deslocamento vertical, tipo de máquina; temperatura ambiente, tamanho e geometria do corpo-de-prova. A an...

  16. Capítulo 4. A imagem predatória da cidade

    OpenAIRE

    Fernandes, Luís

    2018-01-01

    As seduções primeiras A ciência teve de si própria, ao longo de muito tempo, uma imagem que a dizia representação do mundo. A objectividade é a transposição dos objectos da realidade para enunciados rigorosos. Trazer o mundo para dentro da linguagem e, dentro desta, poder exprimir as relações entre fenómenos através do número e da lei — eis o programa que governou a vontade de saber desde o início da modernidade. A visão da ciência como tradução do mundo tem hoje de negociar o seu estatuto na...

  17. La administración educativa y su influencia en el rendimiento académico de los alumnos del nivel secundario en Puno

    OpenAIRE

    Quispe Sairitupa, Míriam Edith

    2011-01-01

    La tesis titulada "La Administración Educativa y su Influencia en el Rendimiento Académico de los Alumnos del Nivel Secundario en Puno" se desarrolló en la ciudad de Puno en el año lectivo 2009, con ocho instituciones educativas del nivel secundario. El objetivo fue determinar la influencia que ejerce la administración educativa en el rendimiento académico de los estudiantes del nivel secundario de la ciudad de Puno, así como establecer el rendimiento académico de los estudiantes cuya direcci...

  18. Influencia de la televisión en los niños Análisis a través del dibujo infantil

    OpenAIRE

    Jiménez Yanez, César; Mancinas Chaves, Rosalba

    2013-01-01

    Este artículo presenta los resultados de un estudio sobre la influencia de la televisión en los niños para el cual se utilizó el dibujo infantil como instrumento de análisis. La televisión, su influencia y el impacto que causa en diversos sectores de la población es un tema bastante estudiado desde distintas disciplinas, en este trabajo el uso del dibujo como herramienta y mecanismo de análisis, es la novedad. El dibujo infantil es un medio de expresión que aporta nuevos elementos para la dis...

  19. La influencia del fenómeno El Niño y del índice de oscilación del sur en las precipitaciones de Cochabamba, Bolivia

    Directory of Open Access Journals (Sweden)

    1998-01-01

    Cochabamba, Bolivia, ubicados entre los 17°20’ y 17°45’ de latitud sur y de 66°05’ y 66°20’ de longitud oeste. Se utilizó la información de 20 estaciones meteorológicas, y las series de TSM del IOS. Las series que se estudiaron fueron divididas en anual, mensual y diaria. Se aplicaron los análisis cualitativo y cuantitativo. Con la aplicación de “Series de Tiempo” se determinó el año hidrológico y las anomalías de las precipitaciones, ajustándose a un promedio móvil de 4 años para las estaciones que reciben la influencia remanente de los frentes del sur y de la Zona de Convergencia Intra tropical-ZCIT y de 5 años para el resto de las estaciones. Se concluyó que la influencia del fenómeno El Niño se da más en las precipitaciones registradas en Cochabamba y con menor incidencia en las precipitaciones registradas en Arani. La influencia del IOS se da más en las precipitaciones de Arani y en menor proporción en las precipitaciones en Cochabamba. Lo cual implica que la influencia del fenómeno El Niño y del Índice de Oscilación del Sur se da en la distribución espacio-temporal de las precipitaciones registradas en los valles de Cochabamba. Esta anomalía afecta directamente la agricultura y de forma indirecta el incremento de los problemas socioeconómicos en el departamento de Cochabamba. “EL NIÑO” PHENOMENON AND SOUTHERN OSCILLATION INDEX INFLUENCE ON THE PRECIPITATION IN COCHABAMBA, BOLIVIA. For a long time, the “El Niño” phenomenon and the Southern Oscillation Index (SOI had been attributed as a factor of less importance on the time-space distribution of the registered atmospheric precipitation in the Cochabamba valley, mainly, and in Bolivia, in general. This study had been carried out at the Alto (upper, Central (middle and Bajo (lower valleys in the Cochabamba department, in Bolivia. These valleys are located between 17°20’ and 17°45’ South, and between 66°05‘and 66°20‘West. The information from 20 meteorological stations, the

  20. A variedade da dieta é fator protetor para a pressão arterial sistólica elevada

    Directory of Open Access Journals (Sweden)

    Erick Prado de Oliveira

    2012-04-01

    Full Text Available FUNDAMENTO: A dieta influencia diretamente a hipertensão arterial (HAS, que é um dos principais fatores de risco da doença cardiovascular. OBJETIVO: Associar a HAS com fatores dietéticos de adultos clinicamente selecionados para programa de mudança de estilo de vida. MÉTODOS: Estudo transversal composto por 335 indivíduos, com idade entre 44 e 65 anos, clinicamente selecionados para um programa de mudança de estilo de vida. Foram avaliados os dados antropométricos (IMC, % de gordura e circunferência abdominal, os componentes bioquímicos (concentrações plasmáticas de glicose, triglicerídeos, colesterol total, HDL-c e LDL-c e a dieta, por meio do recordatório de 24 horas. A qualidade da dieta foi avaliada pelo Índice de Alimentação Saudável. A pressão arterial foi mensurada de acordo com a V Diretriz Brasileira de Hipertensão Arterial e classificada de acordo com o NCEP-ATPIII. A regressão logística foi realizada para determinar a probabilidade de alterações na PAS e PAD de acordo com a ingestão dietética. Adotou-se como significante o valor de p < 0,05. RESULTADOS: Observou-se correlação positiva da pressão arterial diastólica com o consumo de colesterol e açúcar; e negativa com a ingestão de fibras, porções de óleo e qualidade da dieta. A variedade da dieta ≥ 8 itens alimentares apresentou efeito protetor para alterações da pressão arterial sistólica; OR = 0,361 (0,148-0,878. CONCLUSÃO: A maior variedade da dieta ofereceu efeito protetor para alteração da pressão arterial sistólica.

  1. Morphometry and granulosa cells number of preantral ovarian follicles from bovine (“Bos indicus” preserved at 4ºC in saline solution for different periods of time Morfometria e número de células da granulosa de folículos ovarianos pré-antrais de bovino ("Bos indicus" preservados a 4ºC em solução salina por diferentes períodos de tempo

    Directory of Open Access Journals (Sweden)

    Hélder Silva Luna

    2008-04-01

    grupos 12, 24 e 48 h (P > 0,05. Conclui-se que o resfriamento, à temperatura de 4 ºC, não influencia na morfometria folicular e quantidade de células da granulosa.

  2. Os 4Ps do composto de marketing na literatura de Ciência da Informação

    OpenAIRE

    Amaral,Sueli Angelica Do

    2000-01-01

    Analisa 60 documentos sobre os 4Ps do composto de marketing em unidades de informação da literatura de Ciência dei Informação no período de 1975 a 1995, para conhecer quantos e quais autores escreveram sobre o tema, qual o pioneiro, quem foi o pioneiro a propor adição de Ps. Apresenta a cronologia dos documentos estudados e discute as 4Ps do composto de marketing. Propõe a adoção da mais completa proposta analisada como forma de garantir o futuro das unidades de informação.

  3. INFLUENCIA DEL TEMPO DE LA MÚSICA EN LAS EMOCIONES

    OpenAIRE

    Jonathan Azael Caballero-Meneses; Marina Menez

    2010-01-01

    Se sabe que la música puede influir en dos componentes de las emociones: el arousal y la valencia. En particular, se ha reportado que el tempo o rapidez de la música está directamente relacionado con el arousal, aunque su relación con la valencia o medida de afecto no es aún clara. En este trabajo se analizó la influencia del tempo en ambos componentes mediante la exposición de 24 estudiantes de licenciatura a treinta extractos musicales de distinto tempo. Además se evaluó la posible m...

  4. Influencia de la publicidad televisiva peruana en el consumo de alimentos no saludables en escolares de 4º a 6º primaria

    Directory of Open Access Journals (Sweden)

    Evelin C. Rojas-Huayllani

    2013-01-01

    Full Text Available Introducción: La exposición a la publicidad televisiva promueve el consumo de alimentos no saludables, constituyendo un riesgo para el aumento del sobrepeso y obesidad. Objetivo: Determinar la influencia de la publicidad televisiva peruana en el consumo de alimentos no saludables en escolares de 4º a 6º de primaria. Diseño: Descriptivo de asociación cruzada. Lugar: Institución Educativa Nº 7072, Villa El Salvador, Lima, Perú. Participantes: Escolares entre 9 y 12 años de edad. Intervenciones: Se aplicó dos encuestas previamente validadas y probadas en prueba piloto, a 120 escolares de ambos sexos que asistieron a clases y que tuvieron consentimiento informado firmado por sus padres. Principales medidas de resultados: Tiempo de ver televisión y consumo de alimentos no saludables. Resultados: Los estudiantes en promedio vieron televisión más de 7 horas diarias (DS 1,17. Los programas más vistos fueron los que estaban dirigidos a público mayor de 14 años. Los alimentos no saludables más publicitados y comprados fueron galletas y bebidas azucaradas. Se encontró asociación significativa entre alimentos no saludables más vistos en TV y consumo de alimentos no saludables. Conclusiones: Existió relación entre la publicidad televisiva y el consumo de alimentos no saludables en escolares del nivel primario.

  5. The UNC-4 homeobox protein represses mab-9 expression in DA motor neurons in Caenorhabditis elegans

    DEFF Research Database (Denmark)

    Jafari, Gholamali; Appleford, Peter J; Seago, Julian

    2011-01-01

    , an RNAi screen designed to identify upstream transcriptional regulators of mab-9 showed that silencing of unc-4 (encoding a paired-class homeodomain protein) increases mab-9::gfp expression in the nervous system, specifically in posterior DA motor neurons. Over-expression of unc-4 from a heat...

  6. Influencia del modelo elástico en la dinámica de estructuras articuladas

    OpenAIRE

    Muñoz, M.; López-Hernández, E.

    1997-01-01

    Se estudia la influencia en la dinámica de una estructura articulada de barras de madera, de la aproximación a las propiedades tensión-deformación del material. Se ha adoptado un método de cálculo por diferencias finitas en el dominio del tiempo, con un modelo de masas concentradas en los nodos.

  7. La influencia de la publicidad infantil de alimentos: antecedentes y estado de la cuestión

    Directory of Open Access Journals (Sweden)

    Cristina González Díaz

    2013-11-01

    Full Text Available Actualmente estamos asistiendo a un incesante bombardeo de noticias que nos muestran el tipo de productos que la publicidad de alimentos, dirigida específicamente al target infantil, publicita: productos hipercalóricos, con altos niveles en azúcares y sal, etc; en definitiva, productos poco recomendables en la dieta del niño. Al mismo tiempo, no cesan de publicarse investigaciones académicas sobre el poder persuasivo y la capacidad de influencia que este tipo concreto de publicidad posee sobre el niño. Bajo este contexto, este artículo trata de abordar los estudios académicos más significativos que han investigado la posible relación entre la publicidad de alimentos dirigida a niños y la problemática de la obesidad, o más a grandes rasgos, la influencia que la publicidad específica de este sector puede tener en la ingesta de alimentos poco saludables

  8. Uso e influencia de la televisión en la infancia

    OpenAIRE

    Arroyo Jiménez, Isabel

    2012-01-01

    Esta investigación está contextualizada en torno al uso e influencia que ejerce la televisión en la infancia. En concreto hemos escogido un grupo de niños del tercer ciclo de Educación Primaria (10-12 años). Primeramente, tratamos de comprobar el uso que hacen de la televisión los alumnos que hemos tomado como muestra así como el tipo de programas que ven. Posteriormente, analizaremos una pequeña muestra de esos programas más seguidos por nuestros alumnos encuestados. Para ello, partire...

  9. La motivación laboral y su influencia en la empresa

    OpenAIRE

    Jiménez Cacho, Raquel

    2017-01-01

    Este proyecto se centra en un tema de gran interés como es la motivación laboral y su influencia en la empresa. Como sabemos este tema no es nuevo y se ha analizado y estudiado desde hace mucho tiempo, debido a la incidencia que tiene en el mundo laboral, económico y social. La motivación laboral lleva una trayectoria positiva en cuanto a su estudio e importancia, gracias a su estrecha relación con los problemas, soluciones, costes, beneficios y ventajas competitivas de las empresas. Para ...

  10. Perspectivas socioculturais e econômicas da gestão hoteleira: um estudo de caso no Hostel Ralé Chateau – Rio de Janeiro

    OpenAIRE

    Rodrigo Amado dos Santos; Lorene Monteiro Maia; Natan Teixeira Cavalcanti; Mirian Picinini Méxas; Marcelo Jasmim Meiriño

    2016-01-01

    O processo de pacificação das favelas cariocas, por meio das Unidades de Polícia Pacificadora (UPP), não apenas altera o cenário da segurança pública, como também influencia os aspectos econômicos e socioculturais, destacando-se o turismo. Nota-se, a partir dessa política de segurança, um crescente número de turistas interessados em conhecer essas localidades, devido às suas questões sociais e identitárias específicas à cultura carioca. Assim, empresas hoteleiras enxergaram ali não apenas nic...

  11. A GEOGRAFIA DAS TECNOLOGIAS DA INFORMAÇÃO E COMUNICAÇÃO NO BRASIL CONTEMPORÂNEO

    Directory of Open Access Journals (Sweden)

    Vandeir Robson Matias

    2014-03-01

    Full Text Available Entre as tecnologias atuais, destaca-se a internet que influencia o cotidiano das relações socioespaciais, o comércio e as relações internacionais, além de transformar as estruturas físicas que auxiliam na formação do ciberespaço. Castells (2003 observa que, desde meados da década de 1980 ao final da década de 1990, um imenso número de comunidades locais passou a operar online, pois, os movimentos locais pré-intenet estavam em busca de novas oportunidades de auto-organização e elevação das expressões mais politicamente orientadas e governos municipais empenhados em fortalecer sua legitimidade pela criação de novos canais de participação dos cidadãos. Busca-se nesse artigo identificar, compreender e analisar o alcance do uso da internet no Brasil para entender a relação da população brasileira com esse recurso, quantos são os usuários, o que buscam, qual a sua idade, rendimentos, localização, entre outros indicadores. Utilizar-se-ão indicadores quantitativos de perfil dos usuários e aplicações para discutir a espacialização das (TICs e seus elementos pela sociedade brasileira em diferentes regiões e contextos geográficos.

  12. Os 4Ps do composto de marketing na literatura de Ciência da Informação

    Directory of Open Access Journals (Sweden)

    Sueli Angelica Do Amaral

    Full Text Available Analisa 60 documentos sobre os 4Ps do composto de marketing em unidades de informação da literatura de Ciência dei Informação no período de 1975 a 1995, para conhecer quantos e quais autores escreveram sobre o tema, qual o pioneiro, quem foi o pioneiro a propor adição de Ps. Apresenta a cronologia dos documentos estudados e discute as 4Ps do composto de marketing. Propõe a adoção da mais completa proposta analisada como forma de garantir o futuro das unidades de informação.

  13. La centralidad en las comunicaciones y la influencia percibida en los pequeños grupos

    Directory of Open Access Journals (Sweden)

    Nancy Noemi Terroni

    Full Text Available Este trabajo reporta los resultados de medidas del análisis de redes en la comunicación de pequeños grupos que resuelven una tarea de recuperación de memoria y su asociación con la influencia percibida. El reactivo empleado es una historia y los 65 participantes, alumnos de la Universidad Nacional de Mar del Plata, debieron reconstruir la misma primero en forma individual, luego grupal colaborativa y nuevamente en forma individual. Se registraron las interacciones grupales con comunicación cara a cara y mediada por computadora; se analizaron las medidas de prominencia, la centralidad y el prestigio de la comunicación y el tipo de alocución, orientado a la gestión grupal o hacia la tarea. Se observaron asociaciones significativas entre las medidas reticulares y la influencia percibida para ambos medios de comunicación y se hallaron diferencias en la comunicación de gestión grupal. Se discuten estos resultados con relación a las restricciones que imponen los canales de comunicación mediados.

  14. Evolución de la inmunología e influencia en los trasplantes de órganos

    OpenAIRE

    Carretero Vegas, Luz María

    2012-01-01

    Se profundiza en el conocimiento sobre los mecanismos del sistema inmunológico y la evolución histórica de los mismos para conocer la influencia de la inmunología en los trasplantes y las medidas preventivas más adecuadas para evitar las complicaciones

  15. The 10 kDa domain of human erythrocyte protein 4.1 binds the Plasmodium falciparum EBA-181 protein

    Directory of Open Access Journals (Sweden)

    Coetzer Theresa L

    2006-11-01

    Full Text Available Abstract Background Erythrocyte invasion by Plasmodium falciparum parasites represents a key mechanism during malaria pathogenesis. Erythrocyte binding antigen-181 (EBA-181 is an important invasion protein, which mediates a unique host cell entry pathway. A novel interaction between EBA-181 and human erythrocyte membrane protein 4.1 (4.1R was recently demonstrated using phage display technology. In the current study, recombinant proteins were utilized to define and characterize the precise molecular interaction between the two proteins. Methods 4.1R structural domains (30, 16, 10 and 22 kDa domain and the 4.1R binding region in EBA-181 were synthesized in specific Escherichia coli strains as recombinant proteins and purified using magnetic bead technology. Recombinant proteins were subsequently used in blot-overlay and histidine pull-down assays to determine the binding domain in 4.1R. Results Blot overlay and histidine pull-down experiments revealed specific interaction between the 10 kDa domain of 4.1R and EBA-181. Binding was concentration dependent as well as saturable and was abolished by heat denaturation of 4.1R. Conclusion The interaction of EBA-181 with the highly conserved 10 kDa domain of 4.1R provides new insight into the molecular mechanisms utilized by P. falciparum during erythrocyte entry. The results highlight the potential multifunctional role of malaria invasion proteins, which may contribute to the success of the pathogenic stage of the parasite's life cycle.

  16. Uma Análise Multidimensional da Pobreza dos Municípios Paranaenses em 2010

    Directory of Open Access Journals (Sweden)

    Ana Eloísa Giovanetti

    2015-06-01

    Full Text Available O presente trabalho traz uma análise multidimensional da pobreza para os municípios do estado do Paraná, no ano de 2010. Para isso, construiu-se um indicador de pobreza multidimensional (usando o método fuzzy, analisando a proximidade dos municípios quanto aos resultados (estatística I de Moran, estimando, na sequencia, os fatores determinantes dessa pobreza, via econometria espacial. Como resultado observou-se uma concentração dos melhores resultados nas regiões oeste e norte do Paraná. Como determinantes da condição de pobreza, identificaram-se os seguintes fatores, cuja influencia é positiva (ou seja, que tende a elevar a condição de pobreza: razão de dependência, população rural e índice de Gini. E os que exercem efeito negativo (retraindo o índice são: escolaridade, PIB e emprego per capita. Além disso, a defasagem espacial se mostrou relevante, indicando que a pobreza em um determinado município é explicada positivamente pela incidência de pobreza nos municípios vizinhos.

  17. Influência do polimorfismo I/D do gene da eca na HPE de jovens normotensos

    Directory of Open Access Journals (Sweden)

    Manuella de Oliveira Fernandes

    2015-08-01

    Full Text Available INTRODUÇÃO: A hipotensão pós-exercício (HPE é considerada uma estratégia não farmacológica adotada para redução da pressão arterial (PA. Ademais, sabe-se que a presença de alguns polimorfismos genéticos influencia a resposta pressórica, como o I/D do gene da enzima conversora da angiotensina (ECA. Objetivo: Analisar a influência do polimorfismo I/D da ECA sobre a HPE após três diferentes intensidades de exercício em jovens normotensos e fisicamente ativos.MÉTODOS: Vinte e seis jovens saudáveis (DD = 11; ID/II = 15 realizaram uma sessão máxima de 1.600 metros, na pista de atletismo e outras três sessões experimentais (Sessão Moderada: 6% abaixo do limiar anaeróbio, Sessão Intensa: 6% acima do limiar anaeróbio e Sessão de Controle, com aferições prévias da PA, por 20 minutos e posteriores ao exercício por 60 minutos.RESULTADOS: Observou-se que o exercício moderado ocasionou HPE independentemente do grupo genotípico, sendo mais evidente para a pressão arterial sistólica nos momentos 45 minutos e 60 minutos (p ≤ 0,05. Verificou-se também que a característica gênica exerceu influência sobre a área abaixo da curva pressórica (p ≤ 0,005 sobre a pressão arterial diastólica, formada 1 hora após o exercício.CONCLUSÃO: Conclui-se que o exercício moderado ocasiona HPE em jovens normotensos e fisicamente ativos, independentemente do polimorfismo I/D no gene da ECA, sendo que esse polimorfismo exerce influência sobre a hipotensão diastólica, e os indivíduos portadores do alelo I apresentam maior decaimento da PA diastólica (PAD.

  18. Estudo experimental comparando o uso do 2-octil cianoAcrilato ao nylon 4-0 na sutura da pele

    Directory of Open Access Journals (Sweden)

    Ruffo de Freitas-Júnior

    Full Text Available OBJETIVO: Comparar o 2-octil cianoacrilato com o fio de "nylon" no fechamento da pele em ratos. MÉTODOS: Vinte e cinco ratos da linhagem Wistar, foram submetidos à incisão de 3 cm de cada lado do abdome. A síntese foi feita utilizando em um dos lados o "nylon" 4.0, pontos intradérmicos, e do outro o 2-octil cianoacrilato. Após sete dias, o fio foi removido e as incisões, analisadas quanto às complicações. Após 40 dias, o resultado da cicatriz foi avaliado. Os ratos foram sacrificados, as cicatrizes foram ressecadas, fixadas e enviadas ao patologista, sem informação sobre qual o método utilizado. RESULTADOS: Houve dois óbitos durante a anestesia e um tardio. O tempo de operação foi de 136 segundos com a cola e 176 segundos, com o "nylon" (P=0,003. Dentre as 50 operações realizadas, as complicações foram: um hematoma com cada método (P=0,80, quinze deiscências da cola contra 11 do "nylon" (P=0,20, sete cicatrizes de aspecto ruim ou razoável da cola contra quatro do "nylon" (P=0,30, três infecções na cola contra duas (P=0,40. Ao exame patológico, a mediana da largura da cicatriz foi de 1.119 micra com a cola e 1.800 com o "nylon" (P=0,40. A espessura foi de 1.795 contra 1.705 micra (P=0,40. CONCLUSÃO: O 2-octil cianoacrilato apresentou o mesmo aspecto cicatricial, a mesma resistência e as mesmas complicações que a sutura com o "nylon" 4.0, porém permitindo redução no tempo cirúrgico.

  19. Influencia de la Estimulación Temprana a través de Actividades Lúdicas para Mejorar el Desarrollo Cognitivo en los Niños y Niñas de 4 Años de la Institución Educativa Inicial Alto de Amados. Arequipa 2016

    OpenAIRE

    Talavera Guevara, Meilly Juanita

    2017-01-01

    La investigación tiene como enunciado: “Influencia de la estimulación temprana a través de actividades lúdicas para mejorar el desarrollo cognitivo en los niños y niñas de 4 años de la Institución Educativa Inicial Alto de Amados. Arequipa 2016” • La variable independiente es: Estimulación Temprana. • La variable dependiente es: Desarrollo Cognitivo. • Los indicadores para la variable independiente son: Juegos lúdicos. • Los indicadores para la variable dependiente son: Percepció...

  20. Análise funcional e histológica da ação da neurotropina-4 sobre a lesão medular em ratos

    OpenAIRE

    Roberto Minoru Hita

    2008-01-01

    As pesquisas em lesão medular tiveram um avanço significativo nas últimas duas décadas. Várias substâncias têm sido testadas, dentre elas, os fatores neurotróficos que são proteínas que auxiliam na maturação e desenvolvimento do sistema nervoso. O objetivo deste estudo foi conduzir testes que propiciem a análise dos efeitos da recuperação funcional locomotora e regeneração axonal em ratos submetidos a testes experimentais com a utilização da substância neurotropina-4. O estudo consistiu de 30...

  1. Espaço arquitetônico x apropriação: estudo de caso no Centro do Rio de Janeiro - Largo da Carioca e rua Uruguaiana

    Directory of Open Access Journals (Sweden)

    Ethel Pinheiro Santana

    2003-06-01

    Full Text Available O trabalho a ser desenvolvido aborda as formas de apropriação estabelecidas em duas áreas de estudo no centro da cidade do Rio de Janeiro, o Largo da Carioca e a rua Uruguaiana, bem como suas áreas adjacentes, levando em consideração o suporte físico existente - palco de desenvolvimento de sua ocupação formal - e a massa edificada do entorno direto que influencia, estimula e configura a imagem mental e urbana que se tem destas áreas. Com base nos elementos morfológicos de José Lamas¹ , para a apreciação e a análise do entorno físico, e os elementos configuradores do espaço, de acordo com Kevin Lynch² , que permeiam e configuram a noção da imagem que se constrói da cidade, propõe-se um confronto entre a forma arquitetônica estruturadora do espaço, analisada sobre os aspectos físicos, e o domínio humano sobre este, levando em consideração os aspectos sociológicos e apropriativos.

  2. Impacto do polimorfismo genetico da enzima conversora da angiotensina no remodelamento cardiaco

    Directory of Open Access Journals (Sweden)

    Felipe Neves de Albuquerque

    2014-01-01

    Full Text Available Fundamento: O papel dos polimorfismos genéticos da enzima de conversão da angiotensina na insuficiência cardíaca, como preditor de desfechos ecocardiográficos, ainda não está estabelecido. é necessário identificar o perfil local para observar o impacto desses genótipos na população brasileira, sendo inédito o estudo da insuficiência cardíaca de etiologia exclusivamente não isquêmica em seguimento mais longo que 5 anos. Objetivo: Determinar a distribuição das variantes do polimorfismo genético da enzima de conversão da angiotensina e sua relação com a evolução ecocardiográfica de pacientes com insuficiência cardíaca de etiologia não isquêmica. Métodos: Análise secundária de prontuários de 111 pacientes e identificação das variantes do polimorfismo genético da enzima de conversão da angiotensina, classificadas como DD (Deleção/Deleção, DI (Deleção/Inserção ou II (Inserção/Inserção. Resultados: As médias da coorte foram: seguimento de 64,9 meses, idade de 59,5 anos, 60,4% eram homens, 51,4% eram brancos, 98,2% faziam uso de betabloqueadores e 89,2% de inibidores da enzima de conversão da angiotensina ou de bloqueador do receptor da angiotensina. A distribuição do polimorfismo genético da enzima de conversão da angiotensina foi: 51,4% de DD; 44,1% de DI; e 4,5% de II. Não se observou nenhuma diferença das características clínicas ou de tratamento entre os grupos. O diâmetro sistólico do ventrículo esquerdo final foi a única variável ecocardiográfica isolada significativamente diferente entre os polimorfismos genéticos da enzima de conversão da angiotensina: 59,2 ± 1,8 para DD versus 52,3 ± 1,9 para DI versus 59,2 ± 5,2 para II (p = 0,029. No seguimento ecocardiográfico, todas as variáveis (diferença entre a fração de ejeção do ventrículo esquerdo da última e da primeira consulta; diferença entre o diâmetro sistólico do ventrículo esquerdo da última e da primeira

  3. Influencia léxica del muisca en el español actual clasificada en campos semántico

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    DIANA ANDREA GIRALDO GALLEGO

    2014-01-01

    Full Text Available La presencia léxica del muisca en el dialecto cundiboyacense es una muestra de que esta influencia aún sigue vigente. El objetivo de este artículo es presentar los préstamos y posibles préstamos del muisca en el español actual clasificados en campos semánticos. Los datos se recolectaron en los municipios de Machetá y Tibirita en el departamento de Cundinamarca; Guateque, Sutatenza, Guayatá, La Capilla, Garagoa, Chinavita y Pachavita en el departamento de Boyacá. Los resultados se organizaron en siete campos semánticos: campo y cultivo; minería; espacio; animales; familia y ciclo de vida; cuerpo humano; recipientes, alimentación y vivienda. Se concluyó que los campos que presentan una mayor influencia son los que corresponden a cultivo y animales.

  4. Influencia de la microestructura en el comportamiento en fatiga de aceros perlíticos

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    Toledano, M.

    2004-04-01

    Full Text Available This article accounts the relationship between the microstructure of pearlitic steels (influenced by the cold-drawn manufacturing process and the growing rate of sub critical cracks, produced by a cyclic-constant amplitude load. The microstructural study is performed in two levels: the pearlitic colony (first level and the pearlitic lamellar microstructure (second microstructural level. The analysis of the fatigue behaviour was focused on the region II of the fatigue crack propagation regime, in which the crack growing rate per cicle, da/dN, is controlled by the amplitude of the stress intensity range, as described by Paris law. The enhancement of the fatigue behaviour, in the stable growing zone, is related with the progressive orientation of the pearlitic colonies in the cold drawing direction, showing a linear relation between the intersect parameter of the Paris law (mechanical property and the alignment angle of the microstructure.

    Este artículo pretende poner de manifiesto la influencia que los cambios microestructurales inducidos en un acero hipoeutectoide mediante un proceso de trefilado, tienen sobre la velocidad de crecimiento de fisuras sub-críticas, desarrolladas por solicitación cíclica con amplitud de carga constante. El análisis microestructural ha sido realizado a dos niveles: la colonia perlítica (primer nivel y la microestructura laminar de la perlita (segundo nivel microestructural. El análisis del comportamiento en fatiga se ha centrado en la región II del régimen de propagación de fisuras por fatiga, en donde la velocidad de crecimiento de fisuras, da/dN, está controlada por la amplitud del factor de intensidad de tensiones, K, según queda descrito por la ley de Paris. Los resultados obtenidos muestran que la mejora en el comportamiento en fatiga de los aceros, en la zona de crecimiento estable de la fisura, se relaciona con el alineamiento de las colonias perlíticas en la dirección del trefilado

  5. MORTALIDADE FEMININA E ANOS DE VIDA PERDIDOS POR HOMICÍDIO/AGRESSÃO EM CAPITAL BRASILEIRA APÓS PROMULGAÇÃO DA LEI MARIA DA PENHA

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    Nádia de Araújo Amaral

    2013-01-01

    Full Text Available La violencia contra la mujer es un fenómeno que afecta a todas las personas en todas las partes del mundo. En Brasil, en 2006, se promulgó la Ley 11.340/2006, bautizada como Ley Maria da Penha, con la función basilar de cohibir la violencia domestica, familiar y afectiva. La finalidad del estudio fue comparar la mortalidad femenina por agresión/homicidio antes y después de la Ley en Rio Branco, Acre, Brasil. Fue desarrollado un estudio ecológico con víctimas de agresión y homicidios registrados en el Sistema de Información de Mortalidad, del 2002 al 2010. Las mujeres víctimas de homicidio tenían entre 21 e 25 años (28,6%, bajo nivel de escolaridad (39,3% y sin ocupación (64,3%. La incidencia de óbitos mostró disminución seguido por aumento en los últimos dos años, con reflejos en los Años Potenciales de Vida Perdidos en el rango de edad de 16 a 39 años. La Ley Maria da Penha es una realidad en el país y tiene papel relevante en la sociedad por esa razón su efectividad e influencia deben ser analizadas en otras investigaciones.

  6. O passado anulado: os reflexos da inadequada justiça transicional para a democracia brasileira

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    Carla Dóro de Oliveira

    2017-08-01

    Full Text Available O trabalho busca analisar o processo transicional brasileiro pelo estudo das medidas adotadas pelo Estado durante a redemocratização. A partir disso, buscou-se reconhecer os aspectos positivos e negativos do processo justransicional, identificando de que forma sua incompletude influencia na democracia e na persistência de um cenário de violência no país. Na metodologia utilizou-se pesquisa bibliográfica numa abordagem qualitativa. Os resultados do trabalho apontam que medidas adotadas pelo Brasil, apesar de relevantes, são insuficientes para a consolidação de uma cultura democrática e de respeito aos direitos humanos no país, impondo-se, assim, a implementação da justiça transicional em todos os seus aspectos.

  7. Influencia de la densidad en el crecimiento de juveniles de Colossoma macropomum, en jaulas flotantes. Río Nanay, Loreto, Perú

    OpenAIRE

    Ruiz Frias, Angel; Universidad Nacional de la Amazonía Peruana; Pezo Díaz, Roberto; Universidad Nacional de la Amazonía Peruana; Bendayán Acosta, Nora Yonny; Universidad Nacional de la Amazonía Peruana; Tirado Herrera, Emérita Rosabel; Universidad Nacional de la Amazonía Peruana; Sánchez Vela, Carol Margareth; Universidad Nacional de la Amazonía Peruana; Cubas Guerra, Rossana; Universidad Nacional de la Amazonía Peruana; Burga Cabrera, Adriana del Pilar; Universidad Nacional de la Amazonía Peruana; Cardama C., José Antonio; Universidad Nacional de la Amazonía Peruana; Sánchez H., Sandra Milagros; Universidad Nacional de la Amazonía Peruana; MarinhoTorres, Lonnye; Universidad Nacional de la Amazonía Peruana; Fababa Ríos, Denis; Universidad Nacional de la Amazonía Peruana; Arbildo Ortiz, Humberto; Universidad Nacional de la Amazonía Peruana

    2015-01-01

    Se evaluó la influencia de tres densidades de cultivo sobre el crecimiento de juveniles de consumo humano en jaulas flotantes, en monocultivo (gamitana, Colossoma macropomum), con tratamientos (T1: 5, T2: 10 y T3: 15 peces/m3) en el caño San Pedro, cuenca baja del río Nanay, Loreto, Perú. En el monocultivo (2008), se utilizaron noventa peces que fueron alimentados con una dieta extrusada de 22% de proteína bruta, con una tasa de alimentación de 4% de la biomasa de cada jaula. Se monitorearon ...

  8. SANEAMENTO BÁSICO E SEU REFLEXO NAS CONDIÇÕES SOCIOAMBIENTAIS DA ZONA RURAL DO BAIXO MUNIM (MARANHÃO

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    João José Pessoa Mota

    2015-07-01

    Full Text Available O saneamento básico contribui para o equilíbrio da humanidade, através dos serviços de abastecimento de água, disposição dos esgotos sanitários, acondicionamento do lixo e provimento da drenagem. No Brasil 38,4% dos domicílios não estão ligados a uma rede coletora de esgoto, sendo que no Maranhão apenas 19,9% dos domicílios tem esgotamento sanitário adequado, ficando bem abaixo da média da região nordeste que chega a 35,6%. Os serviços de saneamento básico são externalidades positivas de responsabilidade pública e sua provisão é um entrave enfrentado pelos gestores, que devem considerar aspectos da economia, meio ambiente, saúde e educação, prevendo a elevação na utilização dos recursos naturais e a quantidade de resíduos a serem tratados. Objetivou-se analisar os serviços de saneamento básico e suas influencias nas condições socioambientais da zona rural do Baixo Munim – MA. A metodologia utilizada foi a análise quantitativa e qualitativa, envolvendo visitas a campo, registros fotográficos, aplicação de questionários e entrevistas, comparando os valores encontrados. Foram realizados comparativos do PIB e das disposições dos serviços de saneamento entre as regiões do país, apontando diferenças entre a zona rural e urbana, mas também entre as cidades sedes das comunidades objeto de estudo. A região estudada representa uma participação insignificante na composição do PIB do estado, com baixo indicadores de desenvolvimento e com uma evolução insuficiente nos serviços de saneamento. O atendimento por rede de esgoto praticamente não existe na região, sendo baseado no uso de fossas rudimentares, influenciando negativamente a bela paisagem local, comprometendo a qualidade de vida.

  9. Influencia del medio familiar en niños con conductas agresivas

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    Nilo Valentín Noroño Morales

    2002-06-01

    Full Text Available Se realizó un estudio descriptivo, sobre la influencia del medio familiar en niños de 9 a 11 años, con conductas agresivas, evaluados y diagnosticados en el Departamento de Psicología del Policlínico " Dr. Tomás Romay"; la muestra estuvo conformada además, por los padres de estos niños. A todos ellos se les aplicó una serie de técnicas con el objetivo principal de describir las características del medio familiar y su influencia en las conductas agresivas de los infantes. Se concluyó en que como características del medio familiar predominaron las familias disfuncionales incompletas, con manifestaciones de agresividad, alcoholismo, mala integración social y familiar, rechazo hacia los hijos e irresponsabilidad en su cuidado y atención.A descriptive study of the influence of the family environment on children aged 9-11 years old, evaluated and diagnosed at the Psychology Department of "Dr Tomás Romay" polyclinics, was carried out. The children´s parents were also part of the sample. All of them were applied a series of techniques to find out the characteristics of the family environment and its influence on children´s aggressive behaviors. It was concluded that the predominant characteristics were uncompleted dysfunctional families with manifestations of aggressiveness, alcoholism, poor social and family integration, rejection to children and lack of responsibility in relation to their care and attention.

  10. Hedonismo e consumo. O papel do especialista da área do vinho como mediador de experiências.

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    Carla Teixeira

    2016-01-01

    Full Text Available Inscrevendo-se este trabalho no âmbito conjugado da Teoria do Texto e do Interacionismo Sociodiscursivo, defender-se-á que o domínio de uma prática discursiva por parte do produtor textual se reflete no texto.Este ponto de vista será exemplificado a partir da análise de um corpus de géneros textuais que combinam a atividade de produção e de comercialização do vinho com a atividade jornalística, em particular, no género recensão crítica sobre o vinho. Atendendo a que o conjunto de textos observado se integra no que se chama de imprensa “de serviços” moderna que participa da sociedade de hiperconsumo e tendo como dispositivo de análise os tipos de discurso, serão analisadas as representações que o jornalista especialista constrói de si (figuração interna do agir e do seu interlocutor, o leitor-consumidor (figuração externa do agir, posteriormente contrastadas com outros textos jornalísticos sobre o vinho. Os dados demonstrarão que o conhecimento sobre o vinho do especialista influencia diretamente a experiência hedonista que é construída no texto, pelo que só o agir deste sujeito é que pode mediar uma experiência qualificada.

  11. As relações na escola e a construção da autonomia: um estudo da perspectiva da psicologia Relationships in the school and the construction of autonomy: a study from the perspective of psychology

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    Ana Paula Petroni

    2010-08-01

    Full Text Available Este artigo apresenta reflexões de uma pesquisa de Mestrado, que investigou a compreensão de educadores de uma escola pública sobre autonomia e em que medida ver-se ou não como autônomo influencia a atuação docente. Tomou-se como aporte teórico-metodológico os pressupostos de Vigotski e da teoria da Educação Libertadora, de Paulo Freire. Como instrumentos, foram utilizados entrevistas semiestruturadas e relatos de cenas das vivências da pesquisadora nas reuniões docentes. Como resultado, constatou-se que, embora alguns professores se mostrem autorregulados, suas práticas não se caracterizam como autônomas, assim como não se percebem como sujeitos capazes de exercer a autonomia, sobretudo em decorrência das condições materiais em que exercem suas atividades. Evidenciou-se, também, que as formas como as relações se empreendem na escola, permeadas por questões burocráticas e disputa de poder, constituem-se empecilho para o desenvolvimento da autonomia e da emancipação de seus atores.This paper presents some reflections first presented in a Master degree research which has investigated the understanding of educators from a public school about autonomy, and whether seeing themselves as an autonomous being or not has influence in teaching performance. The theoretical basis was drawn from theoretic-methodological ideas of Vigotski and Paulo Freire's Liberative Education theory. The instruments used were semi-structured interviews and accounts of scenes from the experiences of the researcher during the faculty meetings. As a result, it was found that although some teachers demonstrate self regulation, their practices are not characterized as autonomous and do not perceive themselves as subjects capable of exercising autonomy, especially because of the material conditions in which they conduct their activities. It was clear, too, that the ways in which relationships are undertake in school, permeated by bureaucratic issues and

  12. Influencia de la personalidad en la clínica del trastorno de pánico con o sin agorafobia : un estudio exploratorio

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    Osma López, Jorge Javier

    2009-01-01

    El interés científico por determinar los factores de vulnerabilidad relacionados con la psicopatología ha cobrado relevancia en los últimos años. En este sentido, el estudio de las características de personalidad tanto normal como patológica y su influencia en distintos trastornos mentales es un campo del máximo interés para la psicología clínica y la Psicopatología. El trabajo de tesis doctoral que lleva por título "Influencia de la personalidad en la clínica del trastorno de pánico con o si...

  13. Influencia de la pérdida foliar sobre la cosecha en el cv. Gruesa, Musa acuminata Colla (AAA, cultivado bajo invernadero en las Islas Canarias

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    Juan Cabrera Cabrera

    2010-12-01

    Full Text Available El cultivo de la variedad de platanera Gruesa, selección local de Dwarf Cavendish, ha experimentado un importante aumento en los últimos años en las Islas Canarias, tanto al aire libre como bajo invernadero. La eliminación de hojas, tras la floración, es una práctica habitual en los cultivos bajo invernadero. Asimismo es frecuente la pérdida de hojas por el efecto de los vientos en los cultivos al aire libre. El objetivo de este trabajo es evaluar, mediante simulación de pérdida foliar por daños mecánicos, la influencia que tiene la disminución de superficie foliar sobre el llenado y cosecha de la fruta en dicho cultivar. Para ello, cuatro meses antes de la cosecha se efectuaron cinco niveles de defoliación: 0%, 25%, 50%, 75% y 100%. Se valoran dos métodos diferentes de defoliación, eliminación de limbo foliar y tronchado de hojas con posterior corte de éstas. Se analizan y presentan datos morfológicos, fenológicos y productivos, así como valoración de la metodología empleada en este trabajo para la simulación de daños. A partir de un 25% de defoliado, equivalente a 7.5 hojas funcionales por planta, se detectaron diferencias significativas con las plantas testigos.

  14. Influencia de los factores que definen el modelo estético corporal en el bienestar de las mujeres jóvenes afectadas o no afectadas por anorexia y bulimia

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    Victoria Carrillo Durán

    2013-06-01

    Full Text Available OBJETIVO DEL ESTUDIO: El modelo estético corporal actual viene determinado por diferentes factores personales y socioculturales, siendo necesario profundizar su influencia e identificar las dimensiones en que se agrupan. METODOLOGÍA: Para eso, se evaluó la actitud de una muestra de 95 mujeres (saludables y enfermas de anorexia y bulimia frente a la repercusión de su bienestar en determinados factores relacionados con el modelo estético corporal. En segundo lugar, se realizó un análisis factorial de Componentes Principales para determinar las dimensiones en que se agrupan. RESULTADOS Y CONCLUSIONES: Concluímos, que son tres las dimensiones de influencia extraídas: primera: "la dimensión social y de autoestima", segunda: "la dimensión sociocultural relacionada con los medios de comunicación" y tercera: "la dimensión de influencia del compañero y la aceptación". A pesar de ser mayor la influencia de los factores personales, familia, amigos y compañero, la "dimensión sociocultural mediática" es la que determina una diferencia mayor entre ambos grupos.

  15. Espacios y ambientes comerciales. La influencia del contexto en la eficacia comunicativa

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    Martínez Sánchez, Mª Eugenia; Universitat Autònoma de Barcelona. Departament de Comunicació Audiovisual i Publicitat

    2015-01-01

    El ambiente que rodea a un consumidor cuando se encuentra en un establecimiento comercial puede provocar efectos sobre él que deriven en una conducta y comportamiento favorable o desfavorable ante los procesos comunicativos que se producen en él. La investigación surgió de la necesidad de averiguar la capacidad de influencia que poseen los componentes del contexto espacial (color de la pared, iluminación, música, etc.) que rodean al sujeto; es decir, conocer cómo intervienen éstos en el ámbit...

  16. Características de carcaça e da carne de novilhas Charolês e 3/4 Charolês 1/4 Nelore, terminadas em confinamento Carcass and meat characteristics of Charolais and 3/4 Charolais 1/4 Nellore cull heifers, finished in feedlot

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    João Restle

    2001-06-01

    Full Text Available O objetivo deste trabalho foi estudar os aspectos quantitativos e qualitativos da carcaça e da carne de novilhas de descarte dos genótipos Charolês (C e 3/4 C 1/4 Nelore (N. Foram usadas 25 novilhas de três anos, terminadas em confinamento por 80 dias. Não se verificou diferença para peso de abate (473,6 vs. 468,8 kg, peso de carcaça fria (241,8 vs. 241,8 kg, rendimento de carcaça fria (51,09 vs. 51,61%, espessura de gordura (4,13 vs. 4,78 mm, porcentagem de dianteiro (35,52 vs. 36,01% e de costilhar (15,03 vs. 15,42%, conformação (10,75 vs. 10,56 pontos e comprimento de carcaça (127,4 vs. 129,9 cm. As novilhas C apresentaram maior porcentagem do corte serrote (49,95 vs. 48,57% e perímetro de braço (36,73 vs. 35,00 cm que as ¾ C ¼ N. Não houve diferença significativa para a composição física da carcaça, cor (3,46 vs. 3,11 pontos, textura (3,67 vs. 3,33 pontos, marmoreio (6,40 vs. 5,00 pontos, maciez (6,48 vs. 6,19 pontos, palatabilidade (6,33 vs. 6,33 pontos e força para corte das fibras da carne, por meio do aparelho WB-Shear (5,99 vs. 6,24 pontos. A suculência da carne foi melhor nas novilhas C (6,18 vs. 5,67 pontos. A partir desses resultados, pode-se concluir que, para novilhas abatidas aos três anos, não existem diferenças expressivas nos aspectos quantitativos e qualitativos da carcaça e da carne entre os dois genótipos.The objective of this work was to study the quantitative and qualitative carcass and meat characteristics of Charolais (C and 3/4 C 1/4 Nellore (N cull heifers. Twenty-five culled heifers, three years old, were feedlot finished per 80 days period. No significant difference was observed for slaughter weight (473.6 vs. 468.8 kg, cold carcass weight (241.8 vs. 241.8 kg, dressing percentage (51.09 vs. 51.61%, fat thickness (4.13 vs. 4.78 mm, forequarter percentage (35.52 vs. 36.01%, sidecut percentage (15.03 vs. 15.42%, conformation (10.75 vs. 10.56 points and carcass length (127.4 vs. 129.9 cm. The

  17. La influencia social de la televisión: fuentes y métodos de estudio

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    MANUEL MARTÍN SERRANO

    1982-01-01

    Full Text Available Se propone una teoría de la influencia de la televisión, basada en valores de objetividad social. Se analizan como defectuosos los estudios previos sobre el papel de la televisión como mediadora de las relaciones entre el productor, el consumidor y el votante, llevados a cabo por empresas de mercadotecnia porque no promueven un mayor uso social de la televisión. La publicidad se basa en la falsificación y ocultamiento de la realidad. La publicidad política compromete a la democracia al apelar a las emociones más que a la discusión racional. El papel de la televisión en los procesos de socialización esta en función de los modelos significativos de ambos, la televisión y su audiencia: donde estos sistemas de valores y referencia coinciden, la influencia de la televisión será fuerte. Se sugiere que el efecto básico de la televisión no puede ser cambiado sin cambios correlativos en la organización social.

  18. Nivel de influencia de los medios de comunicación sobre la alimentación saludable en adolescentes de colegios públicos de un distrito de Lima

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    Verónica Román

    2010-07-01

    Full Text Available Introducción: Los medios de comunicación tienen gran influencia en el comportamiento de adolescentes; sus mensajes pueden ser potenciadores o perjudiciales para su salud. Objetivos: Determinar el grado de influencia que ejercen los medios de comunicación tanto en estudiantes pertenecientes a escuelas promotoras para el desarrollo sostenible (EDPS como en aquellos que no pertenecen, así como cuáles son aquellos que más influyen sobre alimentación saludable en estudiantes de nivel secundario. Además, determinar si la condición de EDPS se encuentra asociada a una mayor o menor influencia de los medios de comunicación. Diseño: Estudio observacional, descriptivo y transversal. Lugar: Instituciones Educativas del distrito Puente Piedra. Participantes: Adolescentes de ambos sexos. Intervenciones: Trescientos treinta adolescentes fueron elegidos por conveniencia y distribuidos equitativamente entre pertenecientes y no pertenecientes a EPDS. Cada adolescente respondió un cuestionario sobre la influencia percibida de medios de comunicación acerca de alimentación saludable. Se aplicó chi cuadrado para asociar niveles y Man-Whitney, para comparar puntajes. Principales medidas de resultados: Nivel de influencia percibida de medios de comunicación, cuya puntuación fue: 0 a 8 (bajo, 9 a 16 (medio, 17 a 24 (alto. Resultados: El nivel de influencia ‘medio’ obtuvo el mayor porcentaje en ambos grupos. El promedio de puntaje fue 10,9 para los pertenecientes y 10,6 para los no pertenecientes a EPDS, sobre un máximo de 24 puntos. El medio de comunicación que más influyó en la elección de los alimentos para ambos grupos fue la televisión. El que menos influyó para los pertenecientes fue el diario y para los no pertenecientes, la radio. La familia influenciaría más en la elección de alimentos en los pertenecientes a EPDS y los medios de comunicación en los no pertenecientes. Conclusiones: El nivel de influencia de los medios de

  19. Pela reconstrução dos mitos da enfermagem a partir da qualidade emancipatória do cuidado Por la construcción de los mitos de la enfermería a partir de la cualidad emancipatória del cuidado Reconstructing myths of nursing through the emancipatory quality of care

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    Maria Raquel Gomes Maia Pires

    2007-12-01

    Full Text Available Esse estudo teórico se debruça sobre a influencia dos mitos e tradições históricas da enfermagem na prática profissional, presentes em muitos dos seus agentes, à luz triedro emancipatório do cuidar, expresso pelo conhecer para cuidar melhor, cuidar para confrontar, cuidar para emancipar. Remete-se ao estudo da fragilidade política do enfermeiro para desvelar aspectos conservadores e positivistas recorrentes na profissão, fruto da historicidade que a constrói. Objetiva-se refletir teoricamente sobre os discursos conservadores da enfermagem e indicar, com base na perspectiva emancipatória do cuidar, possibilidades para reconstrução do fazer histórico da categoria, ampliando as dimensões da prática social. Propõe-se que a enfermagem assuma os mitos e ritos como ricas contradições da realidade, desmitificando-os reflexivamente por meio da politicidade do cuidado (mediação entre ajuda e poder capaz de forjar autonomias.Ese estudio teórico se inclina so-bre la influencia de los mitos y tradiciones históricas de la enfermería en la práctica profesional, presentes en muchos de sus agentes, a la luz triedro emancipado del cuidar, expreso por el conocer para cuidar mejor, cuidar para confrontar, cuidar para emancipar. Se remete al estudio de la fragilidad política del enfermero para desvelar aspectos conservadores y positivistas recurrentes en la profesión, fruto de la historicidad que la construye. Se objetiva reflejar teóricamente sobre los discursos conservadores de la enfermería e indicar, con base en la perspectiva emancipada del cuidar, posibilidades para la reconstrucción del hacer de la categoría, ampliando las dimensiones de la práctica social. Se propone que la enfermería asuma los mitos y ritos como ricas contradicciones de la realidad, los desmitificando reflexivamente por medio de la politicidade del cuidado (mediación entre ayuda y poder capaz de forjar autonomíasThis theoretical study focuses on the

  20. Repetibilidade da produção, número e peso de frutos de seleções de pitanga roxa

    Directory of Open Access Journals (Sweden)

    José Severino de Lira Júnior

    2010-01-01

    Full Text Available Este trabalho teve como objetivos avaliar a produção, número de frutos e peso do fruto de seleções de pitanga roxa (Eugenia uniflora L. estimar por diferentes métodos seus coefificientes de repetibilidade e o número mínimo de avaliações necessárias para selecioná-las com maior confiabilidade, sob as condições edafoclimáticas da Zona da Mata Norte de Pernambuco. O método de componentes principais mostra-se eficiente para estimar coeficientes de repetibilidade da produção, número de frutos e peso da pitanga. A cultivar Tropicana (fruto vermelho apresenta a maior produção média anual, quando comparada com as pitangas de coloração roxa. Entre as cinco seleções de pitanga roxa, a IPA-15.1 apresenta a maior produção média anual. Para peso do fruto, o melhor resultado foi obtido pela seleção IPA-41.1. Os coeficientes estimados para produção número de frutos e peso da pitanga indicam que a variância ambiental pouco influencia essas características fenotípicas de uma safra para outra. Para produção, número de frutos e peso do fruto são necessárias 2, 2 e 5 safras, respectivamente, para selecionar genótipos superiores de pitanga com 90% de confiabilidade dos resultados.