Educação Física Escolar: desafiando a sua presumível imutabilidade

O presente ensaio tem por objetivo analisar o senso comum que sinaliza para uma presumível imutabilidade ou ineficácia social do componente curricular Educação Física. A premissa da presente elaboração teórica é a de que a Educação Física Escolar comporta um processo evolutivo que aponta para sua legitimidade curricular desafiando, portanto, os corporativismos e as concepções a-históricas provenientes de determinadas esferas acadêmicas e profissionais

Atuação ambulatorial do profissional de educação física no atendimento a crianças e adolescentes obesos

A freqüência da obesidade na infância e adolescência aumentou nos últimos anos. Essa situação tem preocupado a área da saúde, não só pelas conseqüências promovidas pela obesidade na população em geral, mas pela imposição de prejuízos biopsicossociais, ainda na infância. O tratamento é bastante complexo, pois sua causa é multifatorial, exigindo atenção interdisciplinar. O presente trabalho teve como objetivo relatar o papel do professor de educação física na equipe de atendimento ambulatorial de crianças e adolescentes obesos. A atividade física, depois da taxa metabólica basal, é considerada o segundo maior componente do gasto energético diário. Diversos estudos demonstraram que a atividade física associada ao controle alimentar leva a melhores resultados do que essas ações isoladas. O aumento da atividade física é muito benéfico no tratamento de crianças e adolescentes obesos, pois permite maior ingestão alimentar e auxilia a preservar a massa magra. Entretanto, o exercício físico deve ser adaptado às condições de excesso de peso e de crescimento ósseo. Além desses cuidados, o profissional depara-se com a dificuldade de manter crianças e adolescentes em programa de exercício regular. Desse modo, a prescrição do aumento de movimento corporal após a anamnese da rotina diária de cada paciente foi a solução encontrada para, inicialmente, colocá-los em contato com o próprio corpo. Paralelamente, o professor de educação física auxilia a criança a encontrar um tipo de esporte que mais lhe agrade, dentro daqueles permitidos pelo seu excesso de peso e fase de crescimento. Geralmente, recomendam-se atividades que tenham baixo impacto, como nadar, caminhar e andar de bicicleta. O professor de educação física, como educador, deve fazer parte do atendimento multidisciplinar de crianças e adolescentes obesos

A educação física, o docente e a escola: concepções e práticas pedagógicas

Este artigo baseia-se em um estudo que investigou de que maneira as mudanças ocorridas na área da educação física vêm marcando a concepção do professor e a sua prática pedagógica. Trata-se de pesquisa qualitativa, investigando quatro professores de educação física, selecionados segundo os seguintes critérios: atuar no ensino público em escolas diferentes, ter tempo de formado e de docência diferentes entre eles. Os dados foram coletados através de entrevistas recorrentes. Este procedimento baseia-se em algumas etapas de entrevistas seguida de categorização dos dados após cada uma delas. Os sujeitos participam ativamente completando, alterando e esclarecendo informações, interagindo com o pesquisador. Os resultados possibilitaram identificar que as mudanças ocorridas na área da educação física, na visão dos docentes investigados, influenciam desde os aspectos relacionados à formação inicial, passando pelas condições de trabalho na escola e a forma de organizar a prática pedagógica, influenciando na valorização da área, bem como do docente

Energetic ion losses 'channeling' mechanism and strategy for mitigation

Results from two different sets of JET experiments are presented. In experiments in which toroidicity-induced Alfven eigenmodes (TAEs) localized at different radial locations had the same frequencies and toroidal mode numbers, the occurrence of enhanced losses after the excitation of TAEs in the core of the plasma was observed. On the contrary, enhanced losses were not observed if the TAEs localized at different radial locations had different frequencies and toroidal mode numbers. Numerical modeling indicates that, in the first set of experiments, the enhanced losses were caused by a combined effect of the TAEs localized at different radial locations. The TAEs localized in the plasma core transported energetic ions from the core to outer regions of the plasma. Then, the TAEs localized in outer regions of the plasma interacted with these ions just transported by the core-localized TAEs causing a further radial displacement of the ions to the plasma edge. This process eventually ends up causing the loss of the resonant ions. In the second set of experiments, it was found that TAEs localized in the plasma core and in outer regions did not interact with the same ions and so no enhanced losses were measured. Sheared profiles of the safety factor combined with flat mass density profiles lead to larger differences on the frequencies of the TAEs localized at different radial locations, eventually avoiding loss of energetic ions through the described mechanism

Micro ion beam analysis for the erosion of beryllium marker tiles in a tokamak limiter

Beryllium limiter marker tiles were exposed to plasma in the Joint European Torus to diagnose the erosion of main chamber wall materials. A limiter marker tile consists of a beryllium coating layer (7-9 mu m) on the top of bulk beryllium, with a nickel interlayer (2-3 mu m) between them. The thickness variation of the beryllium coating layer, after exposure to plasma, could indicate the erosion measured by ion beam analysis with backscattering spectrometry. However, interpretations from broad beam backscattering spectra were limited by the non-uniform surface structures. Therefore, micro-ion beam analysis (mu-IBA) with 3 MeV proton beam for Elastic back scattering spectrometry (EBS) and PIXE was used to scan samples. The spot size was in the range of 3-10 mu m. Scanned areas were analysed with scanning electron microscopy (SEM) as well. Combining results from mu-IBA and SEM, we obtained local spectra from carefully chosen areas on which the surface structures were relatively uniform. Local spectra suggested that the scanned area (approximate to 600 mu m x 1200 mu m) contained regions with serious erosion with only 2-3 mu m coating beryllium left, regions with intact marker tile, and droplets with 90% beryllium. The nonuniform erosion, droplets mainly formed by beryllium, and the possible mixture of beryllium and nickel were the major reasons that confused interpretation from broad beam EBS

Direct gyrokinetic comparison of pedestal transport in JET with carbon and ITER-like walls

This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another (pulse 92432) from after the installation of JET's ITER-like Wall (ILW). The discharges were selected for a comparison of JET-ILW and JET-C discharges with good confinement at high current (3 MA, corresponding also to low rho(*)) and retain the distinguishing features of JET-C and JET-ILW, notably, decreased pedestal top temperature for JET-ILW. A comparison of the profiles and heating power reveals a stark qualitative difference between the discharges: the JET-ILW pulse (92432) requires twice the heating power, at a gas rate of 1.9 x 10(22) e s(-1), to sustain roughly half the temperature gradient of the JET-C pulse (78697), operated at zero gas rate. This points to heat transport as a central component of the dynamics limiting the JET-ILW pedestal and reinforces the following emerging JET-ILW pedestal transport paradigm, which is proposed for further examination by both theory and experiment. ILW conditions modify the density pedestal in ways that decrease the normalized pedestal density gradient a/L-n, often via an outward shift in relation to the temperature pedestal. This is attributable to some combination of direct metal wall effects and the need for increased fueling to mitigate tungsten contamination. The modification to the density profile increases eta = L-n/L-T, thereby producing more robust ion temperature gradient (ITG) and electron temperature gradient driven instability. The decreased pedestal gradients for JET-ILW (92432) also result in a strongly reduced E x B shear rate, further enhancing the ion scale turbulence. Collectively, these effects limit the pedestal temperature and demand more heating power to achieve good pedestal performance. Our simulations, consistent with basic theoretical arguments, find higher ITG turbulence, stronger stiffness, and higher pedestal transport in the ILW plasma at lower rho(*)

Investigation of deuterium trapping and release in the JET divertor during the third ILW campaign using TDS

Selected set of samples from JET ITER-Like Wall (JET-ILW) divertor tiles exposed in 2015-2016 has been analysed using Thermal Desorption Spectrometry (TDS). The deuterium (D) amounts obtained with TDS were compared with Nuclear Reaction Analysis (NRA). The highest amount of D was found on the top part of inner divertor which has regions with the thickest deposited layers as for divertor tiles removed in 2014. This area resides deep in the scrape-off layer and plasma configurations for the second (ILW-2, 2013-2014) and the third (ILW-3, 2015-2016) JET-ILW campaigns were similar. Agreement between TDS and NRA is good on the apron of Tile 1 and on the upper vertical region whereas on the lower vertical region of Tile 1 the NRA results are clearly smaller than the TDS results. Inner divertor Tile 3 has somewhat less D than Tiles 0 and 1, and the D amount decreases towards the lower part of the tile. The D retention at the divertor inner and outer corner regions is not symmetric as there is more D retention poloidally at the inner than at the outer divertor corner. In most cases the TDS spectra for the ILW-3 samples are different from the corresponding ILW-2 spectra because HD and D-2 release occurs at higher temperatures than from the ILW-2 samples indicating that the low energy traps have been emptied during the plasma operations and that D is either in the energetically deep traps or located deeper in the sample