Cidade de Deus, Lugar Pobre e Violento. Articulando Representações Sociais

A expressiva reprodução da pobreza e da violência nos meios de comunicação de massa, a exemplo da cinematografia brasileira na contemporaneidade, provocam estudos em diversas áreas das ciências humanas e sociais. Esta pesquisa pretende contribuir com estes estudos, objetivando a apreensão das representações sociais de lugar pobre, lugar violento e do filme Cidade de Deus. O aporte teórico e metodológico empregado foi a Teoria do Núcleo Central das Representações Sociais. Participaram desta pesquisa cem sujeitos, divididos em dois grupos; o Grupo 01 foi formado por cinquenta moradores de bairros de classe média e alta e o Grupo 02 formado por cinquenta participantes moradores de bairros periféricos; ambos foram constituídos por moradores dos munícipios de Vitória e Vila Velha, Espírito Santo. Os dados foram coletados por meio de questionário composto por questões de evocação livre, fechadas e abertas. A determinação dos elementos periféricos e dos núcleos centrais das representações ocorreu por meio do software EVOC. Os resultados indicam que as representações sociais de lugar pobre relacionam-se às deficiências estruturais das periferias, à violência e, às carências individuais e coletivas; as representações sociais de lugar violento relacionam-se ao tráfico de drogas, a diferentes formas de violência, e às mortes consequentes do emprego de armas de fogo; e as representações do filme Cidade de Deus agregam elementos próprios das representações de lugar pobre e lugar violento. As similitudes entre elementos de representação dos objetos possibilitam reflexões acerca do papel dos media nos processos de comunicação como formadores e reprodutores das representações sociais. Palavras-chave: ... Cidade de Deus; Crítica cinematográfica

Structuring and support by Alfven waves around prestellar cores

Observations of molecular clouds show the existence of starless, dense cores, threaded by magnetic fields. Observed line widths indicate these dense condensates to be embedded in a supersonically turbulent environment. Under these conditions, the generation of magnetic waves is inevitable. In this paper, we study the structure and support of a 1D plane-parallel, self-gravitating slab, as a monochromatic, circularly polarized Alfven wave is injected in its central plane. Dimensional analysis shows that the solution must depend on three dimensionless parameters. To study the nonlinear, turbulent evolution of such a slab, we use 1D high resolution numerical simulations. For a parameter range inspired by molecular cloud observations, we find the following. 1) A single source of energy injection is sufficient to force persistent supersonic turbulence over several hydrostatic scale heights. 2) The time averaged spatial extension of the slab is comparable to the extension of the stationary, analytical WKB solution. Deviations, as well as the density substructure of the slab, depend on the wave-length of the injected wave. 3) Energy losses are dominated by loss of Poynting-flux and increase with increasing plasma beta. 4) Good spatial resolution is mandatory, making similar simulations in 3D currently prohibitively expensive.Comment: 13 pages, 8 figures, accepted for publication in A&A. The manuscript with full color, high-resolution, figures can be downloaded from http://www.astro.phys.ethz.ch/papers/folini/folini_p_nf.htm

Parallel Monte Carlo Search for Hough Transform

We investigate the problem of line detection in digital image processing and in special how state of the art algorithms behave in the presence of noise and whether CPU efficiency can be improved by the combination of a Monte Carlo Tree Search, hierarchical space decomposition, and parallel computing. The starting point of the investigation is the method introduced in 1962 by Paul Hough for detecting lines in binary images. Extended in the 1970s to the detection of space forms, what came to be known as Hough Transform (HT) has been proposed, for example, in the context of track fitting in the LHC ATLAS and CMS projects. The Hough Transform transfers the problem of line detection, for example, into one of optimization of the peak in a vote counting process for cells which contain the possible points of candidate lines. The detection algorithm can be computationally expensive both in the demands made upon the processor and on memory. Additionally, it can have a reduced effectiveness in detection in the presence of noise. Our first contribution consists in an evaluation of the use of a variation of the Radon Transform as a form of improving theeffectiveness of line detection in the presence of noise. Then, parallel algorithms for variations of the Hough Transform and the Radon Transform for line detection are introduced. An algorithm for Parallel Monte Carlo Search applied to line detection is also introduced. Their algorithmic complexities are discussed. Finally, implementations on multi-GPU and multicore architectures are discussed

Post-LS3 Experimental Options in ECN3

The Experimental Cavern North 3 (ECN3) is an underground experimental cavern on the CERN Pr\'evessin site. ECN3 currently hosts the NA62 experiment, with a physics programme devoted to rare kaon decays and searches of hidden particles approved until Long Shutdown 3 (LS3). Several options are proposed on the longer term in order to make best use of the worldwide unique potential of the high-intensity/high-energy proton beam extracted from the Super Proton Synchrotron (SPS) in ECN3. The current status of their study by the CERN Physics Beyond Colliders (PBC) Study Group is presented, including considerations on beam requirements and upgrades, detector R&D and construction, schedules and cost, as well as physics potential within the CERN and worldwide landscape.Comment: 113 pages, 39 figure

Conceptual Design of a Target and Capture Channel for a Muon Collider

The “target and capture channel” is one of the crucial systems in a Muon Collider, whose function is to create an intense muon beam from the decay of the pions generated by a multi-MW proton beam impinging on a particle-producing target. To guarantee the capture of the pions and resulting muons, the channel consists of a sequence of solenoids, providing a well-defined profile on axis, with 20 T peak at the target location and an adiabatic decrease along the channel length. The solenoids of the channel need substantial shielding from the radiation heat load and dose originating from the nuclear interactions at the target, which results in large bore in excess of 1 m. In this paper we describe a concept for the target and capture solenoid, built with modules whose geometry is optimized to produce the required field profile while minimizing the stored magnetic energy of the system. All solenoids are wound with an internally cooled HTS cable. We focus here on the magnetic and mechanical design of the magnets

Design and behaviour of the Large Hadron Collider external beam dumps capable of receiving 539 MJ/dump

Two 6 t beam dumps, made of a graphite core encapsulated in a stainless steel vessel, are used to absorb the energy of the two Large Hadron Collider (LHC) intense proton beams during operation of the accelerator. Operational issues started to appear in 2015 during LHC Run 2 (2014–2018) as a consequence of the progressive increase of the LHC beam kinetic energy, necessitating technical interventions in the highly radioactive areas around the dumps. Nitrogen gas leaks appeared after highly energetic beam impacts and instrumentation measurements indicated an initially unforeseen movement of the dumps. A computer modelling analysis campaign was launched to understand the origin of these issues, including both Monte Carlo simulations to model the proton beam interaction as well as advanced thermo-mechanical analyses. The main findings were that the amount of instantaneous energy deposited in the dump vessel leads to a strong dynamic response of the whole dump and high accelerations (above 200 g). Based on these findings, an upgraded design, including a new support system and beam windows, was implemented to ensure the dumps' compatibility with the more intense beams foreseen during LHC Run 3 (2022–2025) of 539 MJ per beam. In this paper an integral overview of the operational behaviour of the dumps and the upgraded configurations are discussed.Two 6-t beam dumps, made of a graphite core encapsulated in a stainless steel vessel, are used to absorb the energy of the two Large Hadron Collider (LHC) intense proton beams during operation of the accelerator. Operational issues started to appear in 2015 during LHC Run 2 (2014-2018) as a consequence of the progressive increase of the LHC beam kinetic energy, necessitating technical interventions in the highly radioactive areas around the dumps. Nitrogen gas leaks appeared after highly energetic beam impacts and instrumentation measurements indicated an initially unforeseen movement of the dumps. A computer modelling analysis campaign was launched to understand the origin of these issues, including both Monte Carlo simulations to model the proton beam interaction as well as advanced thermo-mechanical analyses. The main findings were that the amount of instantaneous energy deposited in the dump vessel leads to a strong dynamic response of the whole dump and high accelerations (above 2000g). Based on these findings, an upgraded design, including a new support system and beam windows, was implemented to ensure the dumps' compatibility with the more intense beams foreseen during LHC Run 3 (2022-2025) of 539 MJ per beam. In this paper an integral overview of the operational behaviour of the dumps and the upgraded configurations are discussed

Design of the third-generation lead-based neutron spallation target for the neutron time-of-flight facility at CERN

The neutron time-of-flight (n_TOF) facility at the European Laboratory for Particle Physics (CERN) is a pulsed white-spectrum neutron spallation source producing neutrons for two experimental areas: the Experimental Area 1 (EAR1), located 185 m horizontally from the target, and the Experimental Area 2 (EAR2), located 20 m above the target. The target, based on pure lead, is impacted by a high-intensity 20-GeV/c pulsed proton beam. The facility was conceived to study neutron-nucleus interactions for neutron kinetic energies between a few meV to several GeV, with applications of interest for nuclear astrophysics, nuclear technology, and medical research. After the second-generation target reached the end of its lifetime, the facility underwent a major upgrade during CERN's Long Shutdown 2 (LS2, 2019-2021), which included the installation of the new third-generation neutron target. The first- and second-generation targets were based on water-cooled massive lead blocks and were designed focusing on EAR1, since EAR2 was built later. The new target is cooled by nitrogen gas to avoid erosion-corrosion and contamination of cooling water with radioactive lead spallation products. Moreover, the new design is optimized also for the vertical flight path and EAR2. This paper presents an overview of the target design focused on both physics and thermomechanical performance, and includes a description of the nitrogen cooling circuit and radiation protection studies

Correlation between different Scheimpflug-based lens densitometry analysis and effective phacoemulsification time in mild nuclear cataracts

To assess the correlations between preoperative Scheimpflug-based lens densitometry and effective phacoemulsification time (EPT) in age-related nuclear cataracts.Purpose To assess the correlations between preoperative Scheimpflug-based lens densitometry and effective phacoemulsification time (EPT) in age-related nuclear cataracts. Design Retrospective consecutive study. Methods The setting was the Ophthalmology Department, Hospital de Braga, Portugal. The study population included 50 eyes (42 patients) with age-related nuclear cataracts submitted to uneventful phacoemulsification surgery. Different analysis methods of Scheimpflug-based lens densitometry were performed: Pentacam Nucleus Staging (PNS) score with an ordinal scale from 0 to 5 and three-dimensional (3D), linear and region of interest (ROI) methods, which are displayed on an absolute scale (from 0 to 100%). EPT was calculated for the cataract surgery, which was performed by the same surgeon. Correlations between lens densitometry variables and EPT were determined using Pearson or Spearman correlation coefficients according to data normality. Results There were significant correlations between EPT and average density and maximum density variables derived from the 3D (r = 0.596, p < 0.001; r = 0.632, p < 0.001, respectively) and ROI (r = 0.527, p < 0.001; r = 0.575, p < 0.001, respectively) methods. The average density was the only parameter derived from the linear analysis that showed a significant correlation with EPT (r = 0.293, p = 0.039). The PNS score did not show a significant correlation with EPT (rho = 0.124, p = 0.390). Conclusion The densitometric parameters based on the 3D method showed the highest correlations with EPT. The referred lens densitometric analysis approach may be used in preoperative assessment in order to predict EPT more efficiently in age-related nuclear cataractsinfo:eu-repo/semantics/publishedVersio